cachepc-linux

Fork of AMDESE/linux with modifications for CachePC side-channel attack
git clone https://git.sinitax.com/sinitax/cachepc-linux
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hcd.c (91960B)


      1// SPDX-License-Identifier: GPL-2.0+
      2/*
      3 * (C) Copyright Linus Torvalds 1999
      4 * (C) Copyright Johannes Erdfelt 1999-2001
      5 * (C) Copyright Andreas Gal 1999
      6 * (C) Copyright Gregory P. Smith 1999
      7 * (C) Copyright Deti Fliegl 1999
      8 * (C) Copyright Randy Dunlap 2000
      9 * (C) Copyright David Brownell 2000-2002
     10 */
     11
     12#include <linux/bcd.h>
     13#include <linux/module.h>
     14#include <linux/version.h>
     15#include <linux/kernel.h>
     16#include <linux/sched/task_stack.h>
     17#include <linux/slab.h>
     18#include <linux/completion.h>
     19#include <linux/utsname.h>
     20#include <linux/mm.h>
     21#include <asm/io.h>
     22#include <linux/device.h>
     23#include <linux/dma-mapping.h>
     24#include <linux/mutex.h>
     25#include <asm/irq.h>
     26#include <asm/byteorder.h>
     27#include <asm/unaligned.h>
     28#include <linux/platform_device.h>
     29#include <linux/workqueue.h>
     30#include <linux/pm_runtime.h>
     31#include <linux/types.h>
     32#include <linux/genalloc.h>
     33#include <linux/io.h>
     34#include <linux/kcov.h>
     35
     36#include <linux/phy/phy.h>
     37#include <linux/usb.h>
     38#include <linux/usb/hcd.h>
     39#include <linux/usb/otg.h>
     40
     41#include "usb.h"
     42#include "phy.h"
     43
     44
     45/*-------------------------------------------------------------------------*/
     46
     47/*
     48 * USB Host Controller Driver framework
     49 *
     50 * Plugs into usbcore (usb_bus) and lets HCDs share code, minimizing
     51 * HCD-specific behaviors/bugs.
     52 *
     53 * This does error checks, tracks devices and urbs, and delegates to a
     54 * "hc_driver" only for code (and data) that really needs to know about
     55 * hardware differences.  That includes root hub registers, i/o queues,
     56 * and so on ... but as little else as possible.
     57 *
     58 * Shared code includes most of the "root hub" code (these are emulated,
     59 * though each HC's hardware works differently) and PCI glue, plus request
     60 * tracking overhead.  The HCD code should only block on spinlocks or on
     61 * hardware handshaking; blocking on software events (such as other kernel
     62 * threads releasing resources, or completing actions) is all generic.
     63 *
     64 * Happens the USB 2.0 spec says this would be invisible inside the "USBD",
     65 * and includes mostly a "HCDI" (HCD Interface) along with some APIs used
     66 * only by the hub driver ... and that neither should be seen or used by
     67 * usb client device drivers.
     68 *
     69 * Contributors of ideas or unattributed patches include: David Brownell,
     70 * Roman Weissgaerber, Rory Bolt, Greg Kroah-Hartman, ...
     71 *
     72 * HISTORY:
     73 * 2002-02-21	Pull in most of the usb_bus support from usb.c; some
     74 *		associated cleanup.  "usb_hcd" still != "usb_bus".
     75 * 2001-12-12	Initial patch version for Linux 2.5.1 kernel.
     76 */
     77
     78/*-------------------------------------------------------------------------*/
     79
     80/* Keep track of which host controller drivers are loaded */
     81unsigned long usb_hcds_loaded;
     82EXPORT_SYMBOL_GPL(usb_hcds_loaded);
     83
     84/* host controllers we manage */
     85DEFINE_IDR (usb_bus_idr);
     86EXPORT_SYMBOL_GPL (usb_bus_idr);
     87
     88/* used when allocating bus numbers */
     89#define USB_MAXBUS		64
     90
     91/* used when updating list of hcds */
     92DEFINE_MUTEX(usb_bus_idr_lock);	/* exported only for usbfs */
     93EXPORT_SYMBOL_GPL (usb_bus_idr_lock);
     94
     95/* used for controlling access to virtual root hubs */
     96static DEFINE_SPINLOCK(hcd_root_hub_lock);
     97
     98/* used when updating an endpoint's URB list */
     99static DEFINE_SPINLOCK(hcd_urb_list_lock);
    100
    101/* used to protect against unlinking URBs after the device is gone */
    102static DEFINE_SPINLOCK(hcd_urb_unlink_lock);
    103
    104/* wait queue for synchronous unlinks */
    105DECLARE_WAIT_QUEUE_HEAD(usb_kill_urb_queue);
    106
    107/*-------------------------------------------------------------------------*/
    108
    109/*
    110 * Sharable chunks of root hub code.
    111 */
    112
    113/*-------------------------------------------------------------------------*/
    114#define KERNEL_REL	bin2bcd(LINUX_VERSION_MAJOR)
    115#define KERNEL_VER	bin2bcd(LINUX_VERSION_PATCHLEVEL)
    116
    117/* usb 3.1 root hub device descriptor */
    118static const u8 usb31_rh_dev_descriptor[18] = {
    119	0x12,       /*  __u8  bLength; */
    120	USB_DT_DEVICE, /* __u8 bDescriptorType; Device */
    121	0x10, 0x03, /*  __le16 bcdUSB; v3.1 */
    122
    123	0x09,	    /*  __u8  bDeviceClass; HUB_CLASSCODE */
    124	0x00,	    /*  __u8  bDeviceSubClass; */
    125	0x03,       /*  __u8  bDeviceProtocol; USB 3 hub */
    126	0x09,       /*  __u8  bMaxPacketSize0; 2^9 = 512 Bytes */
    127
    128	0x6b, 0x1d, /*  __le16 idVendor; Linux Foundation 0x1d6b */
    129	0x03, 0x00, /*  __le16 idProduct; device 0x0003 */
    130	KERNEL_VER, KERNEL_REL, /*  __le16 bcdDevice */
    131
    132	0x03,       /*  __u8  iManufacturer; */
    133	0x02,       /*  __u8  iProduct; */
    134	0x01,       /*  __u8  iSerialNumber; */
    135	0x01        /*  __u8  bNumConfigurations; */
    136};
    137
    138/* usb 3.0 root hub device descriptor */
    139static const u8 usb3_rh_dev_descriptor[18] = {
    140	0x12,       /*  __u8  bLength; */
    141	USB_DT_DEVICE, /* __u8 bDescriptorType; Device */
    142	0x00, 0x03, /*  __le16 bcdUSB; v3.0 */
    143
    144	0x09,	    /*  __u8  bDeviceClass; HUB_CLASSCODE */
    145	0x00,	    /*  __u8  bDeviceSubClass; */
    146	0x03,       /*  __u8  bDeviceProtocol; USB 3.0 hub */
    147	0x09,       /*  __u8  bMaxPacketSize0; 2^9 = 512 Bytes */
    148
    149	0x6b, 0x1d, /*  __le16 idVendor; Linux Foundation 0x1d6b */
    150	0x03, 0x00, /*  __le16 idProduct; device 0x0003 */
    151	KERNEL_VER, KERNEL_REL, /*  __le16 bcdDevice */
    152
    153	0x03,       /*  __u8  iManufacturer; */
    154	0x02,       /*  __u8  iProduct; */
    155	0x01,       /*  __u8  iSerialNumber; */
    156	0x01        /*  __u8  bNumConfigurations; */
    157};
    158
    159/* usb 2.5 (wireless USB 1.0) root hub device descriptor */
    160static const u8 usb25_rh_dev_descriptor[18] = {
    161	0x12,       /*  __u8  bLength; */
    162	USB_DT_DEVICE, /* __u8 bDescriptorType; Device */
    163	0x50, 0x02, /*  __le16 bcdUSB; v2.5 */
    164
    165	0x09,	    /*  __u8  bDeviceClass; HUB_CLASSCODE */
    166	0x00,	    /*  __u8  bDeviceSubClass; */
    167	0x00,       /*  __u8  bDeviceProtocol; [ usb 2.0 no TT ] */
    168	0xFF,       /*  __u8  bMaxPacketSize0; always 0xFF (WUSB Spec 7.4.1). */
    169
    170	0x6b, 0x1d, /*  __le16 idVendor; Linux Foundation 0x1d6b */
    171	0x02, 0x00, /*  __le16 idProduct; device 0x0002 */
    172	KERNEL_VER, KERNEL_REL, /*  __le16 bcdDevice */
    173
    174	0x03,       /*  __u8  iManufacturer; */
    175	0x02,       /*  __u8  iProduct; */
    176	0x01,       /*  __u8  iSerialNumber; */
    177	0x01        /*  __u8  bNumConfigurations; */
    178};
    179
    180/* usb 2.0 root hub device descriptor */
    181static const u8 usb2_rh_dev_descriptor[18] = {
    182	0x12,       /*  __u8  bLength; */
    183	USB_DT_DEVICE, /* __u8 bDescriptorType; Device */
    184	0x00, 0x02, /*  __le16 bcdUSB; v2.0 */
    185
    186	0x09,	    /*  __u8  bDeviceClass; HUB_CLASSCODE */
    187	0x00,	    /*  __u8  bDeviceSubClass; */
    188	0x00,       /*  __u8  bDeviceProtocol; [ usb 2.0 no TT ] */
    189	0x40,       /*  __u8  bMaxPacketSize0; 64 Bytes */
    190
    191	0x6b, 0x1d, /*  __le16 idVendor; Linux Foundation 0x1d6b */
    192	0x02, 0x00, /*  __le16 idProduct; device 0x0002 */
    193	KERNEL_VER, KERNEL_REL, /*  __le16 bcdDevice */
    194
    195	0x03,       /*  __u8  iManufacturer; */
    196	0x02,       /*  __u8  iProduct; */
    197	0x01,       /*  __u8  iSerialNumber; */
    198	0x01        /*  __u8  bNumConfigurations; */
    199};
    200
    201/* no usb 2.0 root hub "device qualifier" descriptor: one speed only */
    202
    203/* usb 1.1 root hub device descriptor */
    204static const u8 usb11_rh_dev_descriptor[18] = {
    205	0x12,       /*  __u8  bLength; */
    206	USB_DT_DEVICE, /* __u8 bDescriptorType; Device */
    207	0x10, 0x01, /*  __le16 bcdUSB; v1.1 */
    208
    209	0x09,	    /*  __u8  bDeviceClass; HUB_CLASSCODE */
    210	0x00,	    /*  __u8  bDeviceSubClass; */
    211	0x00,       /*  __u8  bDeviceProtocol; [ low/full speeds only ] */
    212	0x40,       /*  __u8  bMaxPacketSize0; 64 Bytes */
    213
    214	0x6b, 0x1d, /*  __le16 idVendor; Linux Foundation 0x1d6b */
    215	0x01, 0x00, /*  __le16 idProduct; device 0x0001 */
    216	KERNEL_VER, KERNEL_REL, /*  __le16 bcdDevice */
    217
    218	0x03,       /*  __u8  iManufacturer; */
    219	0x02,       /*  __u8  iProduct; */
    220	0x01,       /*  __u8  iSerialNumber; */
    221	0x01        /*  __u8  bNumConfigurations; */
    222};
    223
    224
    225/*-------------------------------------------------------------------------*/
    226
    227/* Configuration descriptors for our root hubs */
    228
    229static const u8 fs_rh_config_descriptor[] = {
    230
    231	/* one configuration */
    232	0x09,       /*  __u8  bLength; */
    233	USB_DT_CONFIG, /* __u8 bDescriptorType; Configuration */
    234	0x19, 0x00, /*  __le16 wTotalLength; */
    235	0x01,       /*  __u8  bNumInterfaces; (1) */
    236	0x01,       /*  __u8  bConfigurationValue; */
    237	0x00,       /*  __u8  iConfiguration; */
    238	0xc0,       /*  __u8  bmAttributes;
    239				 Bit 7: must be set,
    240				     6: Self-powered,
    241				     5: Remote wakeup,
    242				     4..0: resvd */
    243	0x00,       /*  __u8  MaxPower; */
    244
    245	/* USB 1.1:
    246	 * USB 2.0, single TT organization (mandatory):
    247	 *	one interface, protocol 0
    248	 *
    249	 * USB 2.0, multiple TT organization (optional):
    250	 *	two interfaces, protocols 1 (like single TT)
    251	 *	and 2 (multiple TT mode) ... config is
    252	 *	sometimes settable
    253	 *	NOT IMPLEMENTED
    254	 */
    255
    256	/* one interface */
    257	0x09,       /*  __u8  if_bLength; */
    258	USB_DT_INTERFACE,  /* __u8 if_bDescriptorType; Interface */
    259	0x00,       /*  __u8  if_bInterfaceNumber; */
    260	0x00,       /*  __u8  if_bAlternateSetting; */
    261	0x01,       /*  __u8  if_bNumEndpoints; */
    262	0x09,       /*  __u8  if_bInterfaceClass; HUB_CLASSCODE */
    263	0x00,       /*  __u8  if_bInterfaceSubClass; */
    264	0x00,       /*  __u8  if_bInterfaceProtocol; [usb1.1 or single tt] */
    265	0x00,       /*  __u8  if_iInterface; */
    266
    267	/* one endpoint (status change endpoint) */
    268	0x07,       /*  __u8  ep_bLength; */
    269	USB_DT_ENDPOINT, /* __u8 ep_bDescriptorType; Endpoint */
    270	0x81,       /*  __u8  ep_bEndpointAddress; IN Endpoint 1 */
    271	0x03,       /*  __u8  ep_bmAttributes; Interrupt */
    272	0x02, 0x00, /*  __le16 ep_wMaxPacketSize; 1 + (MAX_ROOT_PORTS / 8) */
    273	0xff        /*  __u8  ep_bInterval; (255ms -- usb 2.0 spec) */
    274};
    275
    276static const u8 hs_rh_config_descriptor[] = {
    277
    278	/* one configuration */
    279	0x09,       /*  __u8  bLength; */
    280	USB_DT_CONFIG, /* __u8 bDescriptorType; Configuration */
    281	0x19, 0x00, /*  __le16 wTotalLength; */
    282	0x01,       /*  __u8  bNumInterfaces; (1) */
    283	0x01,       /*  __u8  bConfigurationValue; */
    284	0x00,       /*  __u8  iConfiguration; */
    285	0xc0,       /*  __u8  bmAttributes;
    286				 Bit 7: must be set,
    287				     6: Self-powered,
    288				     5: Remote wakeup,
    289				     4..0: resvd */
    290	0x00,       /*  __u8  MaxPower; */
    291
    292	/* USB 1.1:
    293	 * USB 2.0, single TT organization (mandatory):
    294	 *	one interface, protocol 0
    295	 *
    296	 * USB 2.0, multiple TT organization (optional):
    297	 *	two interfaces, protocols 1 (like single TT)
    298	 *	and 2 (multiple TT mode) ... config is
    299	 *	sometimes settable
    300	 *	NOT IMPLEMENTED
    301	 */
    302
    303	/* one interface */
    304	0x09,       /*  __u8  if_bLength; */
    305	USB_DT_INTERFACE, /* __u8 if_bDescriptorType; Interface */
    306	0x00,       /*  __u8  if_bInterfaceNumber; */
    307	0x00,       /*  __u8  if_bAlternateSetting; */
    308	0x01,       /*  __u8  if_bNumEndpoints; */
    309	0x09,       /*  __u8  if_bInterfaceClass; HUB_CLASSCODE */
    310	0x00,       /*  __u8  if_bInterfaceSubClass; */
    311	0x00,       /*  __u8  if_bInterfaceProtocol; [usb1.1 or single tt] */
    312	0x00,       /*  __u8  if_iInterface; */
    313
    314	/* one endpoint (status change endpoint) */
    315	0x07,       /*  __u8  ep_bLength; */
    316	USB_DT_ENDPOINT, /* __u8 ep_bDescriptorType; Endpoint */
    317	0x81,       /*  __u8  ep_bEndpointAddress; IN Endpoint 1 */
    318	0x03,       /*  __u8  ep_bmAttributes; Interrupt */
    319		    /* __le16 ep_wMaxPacketSize; 1 + (MAX_ROOT_PORTS / 8)
    320		     * see hub.c:hub_configure() for details. */
    321	(USB_MAXCHILDREN + 1 + 7) / 8, 0x00,
    322	0x0c        /*  __u8  ep_bInterval; (256ms -- usb 2.0 spec) */
    323};
    324
    325static const u8 ss_rh_config_descriptor[] = {
    326	/* one configuration */
    327	0x09,       /*  __u8  bLength; */
    328	USB_DT_CONFIG, /* __u8 bDescriptorType; Configuration */
    329	0x1f, 0x00, /*  __le16 wTotalLength; */
    330	0x01,       /*  __u8  bNumInterfaces; (1) */
    331	0x01,       /*  __u8  bConfigurationValue; */
    332	0x00,       /*  __u8  iConfiguration; */
    333	0xc0,       /*  __u8  bmAttributes;
    334				 Bit 7: must be set,
    335				     6: Self-powered,
    336				     5: Remote wakeup,
    337				     4..0: resvd */
    338	0x00,       /*  __u8  MaxPower; */
    339
    340	/* one interface */
    341	0x09,       /*  __u8  if_bLength; */
    342	USB_DT_INTERFACE, /* __u8 if_bDescriptorType; Interface */
    343	0x00,       /*  __u8  if_bInterfaceNumber; */
    344	0x00,       /*  __u8  if_bAlternateSetting; */
    345	0x01,       /*  __u8  if_bNumEndpoints; */
    346	0x09,       /*  __u8  if_bInterfaceClass; HUB_CLASSCODE */
    347	0x00,       /*  __u8  if_bInterfaceSubClass; */
    348	0x00,       /*  __u8  if_bInterfaceProtocol; */
    349	0x00,       /*  __u8  if_iInterface; */
    350
    351	/* one endpoint (status change endpoint) */
    352	0x07,       /*  __u8  ep_bLength; */
    353	USB_DT_ENDPOINT, /* __u8 ep_bDescriptorType; Endpoint */
    354	0x81,       /*  __u8  ep_bEndpointAddress; IN Endpoint 1 */
    355	0x03,       /*  __u8  ep_bmAttributes; Interrupt */
    356		    /* __le16 ep_wMaxPacketSize; 1 + (MAX_ROOT_PORTS / 8)
    357		     * see hub.c:hub_configure() for details. */
    358	(USB_MAXCHILDREN + 1 + 7) / 8, 0x00,
    359	0x0c,       /*  __u8  ep_bInterval; (256ms -- usb 2.0 spec) */
    360
    361	/* one SuperSpeed endpoint companion descriptor */
    362	0x06,        /* __u8 ss_bLength */
    363	USB_DT_SS_ENDPOINT_COMP, /* __u8 ss_bDescriptorType; SuperSpeed EP */
    364		     /* Companion */
    365	0x00,        /* __u8 ss_bMaxBurst; allows 1 TX between ACKs */
    366	0x00,        /* __u8 ss_bmAttributes; 1 packet per service interval */
    367	0x02, 0x00   /* __le16 ss_wBytesPerInterval; 15 bits for max 15 ports */
    368};
    369
    370/* authorized_default behaviour:
    371 * -1 is authorized for all devices except wireless (old behaviour)
    372 * 0 is unauthorized for all devices
    373 * 1 is authorized for all devices
    374 * 2 is authorized for internal devices
    375 */
    376#define USB_AUTHORIZE_WIRED	-1
    377#define USB_AUTHORIZE_NONE	0
    378#define USB_AUTHORIZE_ALL	1
    379#define USB_AUTHORIZE_INTERNAL	2
    380
    381static int authorized_default = USB_AUTHORIZE_WIRED;
    382module_param(authorized_default, int, S_IRUGO|S_IWUSR);
    383MODULE_PARM_DESC(authorized_default,
    384		"Default USB device authorization: 0 is not authorized, 1 is "
    385		"authorized, 2 is authorized for internal devices, -1 is "
    386		"authorized except for wireless USB (default, old behaviour)");
    387/*-------------------------------------------------------------------------*/
    388
    389/**
    390 * ascii2desc() - Helper routine for producing UTF-16LE string descriptors
    391 * @s: Null-terminated ASCII (actually ISO-8859-1) string
    392 * @buf: Buffer for USB string descriptor (header + UTF-16LE)
    393 * @len: Length (in bytes; may be odd) of descriptor buffer.
    394 *
    395 * Return: The number of bytes filled in: 2 + 2*strlen(s) or @len,
    396 * whichever is less.
    397 *
    398 * Note:
    399 * USB String descriptors can contain at most 126 characters; input
    400 * strings longer than that are truncated.
    401 */
    402static unsigned
    403ascii2desc(char const *s, u8 *buf, unsigned len)
    404{
    405	unsigned n, t = 2 + 2*strlen(s);
    406
    407	if (t > 254)
    408		t = 254;	/* Longest possible UTF string descriptor */
    409	if (len > t)
    410		len = t;
    411
    412	t += USB_DT_STRING << 8;	/* Now t is first 16 bits to store */
    413
    414	n = len;
    415	while (n--) {
    416		*buf++ = t;
    417		if (!n--)
    418			break;
    419		*buf++ = t >> 8;
    420		t = (unsigned char)*s++;
    421	}
    422	return len;
    423}
    424
    425/**
    426 * rh_string() - provides string descriptors for root hub
    427 * @id: the string ID number (0: langids, 1: serial #, 2: product, 3: vendor)
    428 * @hcd: the host controller for this root hub
    429 * @data: buffer for output packet
    430 * @len: length of the provided buffer
    431 *
    432 * Produces either a manufacturer, product or serial number string for the
    433 * virtual root hub device.
    434 *
    435 * Return: The number of bytes filled in: the length of the descriptor or
    436 * of the provided buffer, whichever is less.
    437 */
    438static unsigned
    439rh_string(int id, struct usb_hcd const *hcd, u8 *data, unsigned len)
    440{
    441	char buf[100];
    442	char const *s;
    443	static char const langids[4] = {4, USB_DT_STRING, 0x09, 0x04};
    444
    445	/* language ids */
    446	switch (id) {
    447	case 0:
    448		/* Array of LANGID codes (0x0409 is MSFT-speak for "en-us") */
    449		/* See http://www.usb.org/developers/docs/USB_LANGIDs.pdf */
    450		if (len > 4)
    451			len = 4;
    452		memcpy(data, langids, len);
    453		return len;
    454	case 1:
    455		/* Serial number */
    456		s = hcd->self.bus_name;
    457		break;
    458	case 2:
    459		/* Product name */
    460		s = hcd->product_desc;
    461		break;
    462	case 3:
    463		/* Manufacturer */
    464		snprintf (buf, sizeof buf, "%s %s %s", init_utsname()->sysname,
    465			init_utsname()->release, hcd->driver->description);
    466		s = buf;
    467		break;
    468	default:
    469		/* Can't happen; caller guarantees it */
    470		return 0;
    471	}
    472
    473	return ascii2desc(s, data, len);
    474}
    475
    476
    477/* Root hub control transfers execute synchronously */
    478static int rh_call_control (struct usb_hcd *hcd, struct urb *urb)
    479{
    480	struct usb_ctrlrequest *cmd;
    481	u16		typeReq, wValue, wIndex, wLength;
    482	u8		*ubuf = urb->transfer_buffer;
    483	unsigned	len = 0;
    484	int		status;
    485	u8		patch_wakeup = 0;
    486	u8		patch_protocol = 0;
    487	u16		tbuf_size;
    488	u8		*tbuf = NULL;
    489	const u8	*bufp;
    490
    491	might_sleep();
    492
    493	spin_lock_irq(&hcd_root_hub_lock);
    494	status = usb_hcd_link_urb_to_ep(hcd, urb);
    495	spin_unlock_irq(&hcd_root_hub_lock);
    496	if (status)
    497		return status;
    498	urb->hcpriv = hcd;	/* Indicate it's queued */
    499
    500	cmd = (struct usb_ctrlrequest *) urb->setup_packet;
    501	typeReq  = (cmd->bRequestType << 8) | cmd->bRequest;
    502	wValue   = le16_to_cpu (cmd->wValue);
    503	wIndex   = le16_to_cpu (cmd->wIndex);
    504	wLength  = le16_to_cpu (cmd->wLength);
    505
    506	if (wLength > urb->transfer_buffer_length)
    507		goto error;
    508
    509	/*
    510	 * tbuf should be at least as big as the
    511	 * USB hub descriptor.
    512	 */
    513	tbuf_size =  max_t(u16, sizeof(struct usb_hub_descriptor), wLength);
    514	tbuf = kzalloc(tbuf_size, GFP_KERNEL);
    515	if (!tbuf) {
    516		status = -ENOMEM;
    517		goto err_alloc;
    518	}
    519
    520	bufp = tbuf;
    521
    522
    523	urb->actual_length = 0;
    524	switch (typeReq) {
    525
    526	/* DEVICE REQUESTS */
    527
    528	/* The root hub's remote wakeup enable bit is implemented using
    529	 * driver model wakeup flags.  If this system supports wakeup
    530	 * through USB, userspace may change the default "allow wakeup"
    531	 * policy through sysfs or these calls.
    532	 *
    533	 * Most root hubs support wakeup from downstream devices, for
    534	 * runtime power management (disabling USB clocks and reducing
    535	 * VBUS power usage).  However, not all of them do so; silicon,
    536	 * board, and BIOS bugs here are not uncommon, so these can't
    537	 * be treated quite like external hubs.
    538	 *
    539	 * Likewise, not all root hubs will pass wakeup events upstream,
    540	 * to wake up the whole system.  So don't assume root hub and
    541	 * controller capabilities are identical.
    542	 */
    543
    544	case DeviceRequest | USB_REQ_GET_STATUS:
    545		tbuf[0] = (device_may_wakeup(&hcd->self.root_hub->dev)
    546					<< USB_DEVICE_REMOTE_WAKEUP)
    547				| (1 << USB_DEVICE_SELF_POWERED);
    548		tbuf[1] = 0;
    549		len = 2;
    550		break;
    551	case DeviceOutRequest | USB_REQ_CLEAR_FEATURE:
    552		if (wValue == USB_DEVICE_REMOTE_WAKEUP)
    553			device_set_wakeup_enable(&hcd->self.root_hub->dev, 0);
    554		else
    555			goto error;
    556		break;
    557	case DeviceOutRequest | USB_REQ_SET_FEATURE:
    558		if (device_can_wakeup(&hcd->self.root_hub->dev)
    559				&& wValue == USB_DEVICE_REMOTE_WAKEUP)
    560			device_set_wakeup_enable(&hcd->self.root_hub->dev, 1);
    561		else
    562			goto error;
    563		break;
    564	case DeviceRequest | USB_REQ_GET_CONFIGURATION:
    565		tbuf[0] = 1;
    566		len = 1;
    567		fallthrough;
    568	case DeviceOutRequest | USB_REQ_SET_CONFIGURATION:
    569		break;
    570	case DeviceRequest | USB_REQ_GET_DESCRIPTOR:
    571		switch (wValue & 0xff00) {
    572		case USB_DT_DEVICE << 8:
    573			switch (hcd->speed) {
    574			case HCD_USB32:
    575			case HCD_USB31:
    576				bufp = usb31_rh_dev_descriptor;
    577				break;
    578			case HCD_USB3:
    579				bufp = usb3_rh_dev_descriptor;
    580				break;
    581			case HCD_USB25:
    582				bufp = usb25_rh_dev_descriptor;
    583				break;
    584			case HCD_USB2:
    585				bufp = usb2_rh_dev_descriptor;
    586				break;
    587			case HCD_USB11:
    588				bufp = usb11_rh_dev_descriptor;
    589				break;
    590			default:
    591				goto error;
    592			}
    593			len = 18;
    594			if (hcd->has_tt)
    595				patch_protocol = 1;
    596			break;
    597		case USB_DT_CONFIG << 8:
    598			switch (hcd->speed) {
    599			case HCD_USB32:
    600			case HCD_USB31:
    601			case HCD_USB3:
    602				bufp = ss_rh_config_descriptor;
    603				len = sizeof ss_rh_config_descriptor;
    604				break;
    605			case HCD_USB25:
    606			case HCD_USB2:
    607				bufp = hs_rh_config_descriptor;
    608				len = sizeof hs_rh_config_descriptor;
    609				break;
    610			case HCD_USB11:
    611				bufp = fs_rh_config_descriptor;
    612				len = sizeof fs_rh_config_descriptor;
    613				break;
    614			default:
    615				goto error;
    616			}
    617			if (device_can_wakeup(&hcd->self.root_hub->dev))
    618				patch_wakeup = 1;
    619			break;
    620		case USB_DT_STRING << 8:
    621			if ((wValue & 0xff) < 4)
    622				urb->actual_length = rh_string(wValue & 0xff,
    623						hcd, ubuf, wLength);
    624			else /* unsupported IDs --> "protocol stall" */
    625				goto error;
    626			break;
    627		case USB_DT_BOS << 8:
    628			goto nongeneric;
    629		default:
    630			goto error;
    631		}
    632		break;
    633	case DeviceRequest | USB_REQ_GET_INTERFACE:
    634		tbuf[0] = 0;
    635		len = 1;
    636		fallthrough;
    637	case DeviceOutRequest | USB_REQ_SET_INTERFACE:
    638		break;
    639	case DeviceOutRequest | USB_REQ_SET_ADDRESS:
    640		/* wValue == urb->dev->devaddr */
    641		dev_dbg (hcd->self.controller, "root hub device address %d\n",
    642			wValue);
    643		break;
    644
    645	/* INTERFACE REQUESTS (no defined feature/status flags) */
    646
    647	/* ENDPOINT REQUESTS */
    648
    649	case EndpointRequest | USB_REQ_GET_STATUS:
    650		/* ENDPOINT_HALT flag */
    651		tbuf[0] = 0;
    652		tbuf[1] = 0;
    653		len = 2;
    654		fallthrough;
    655	case EndpointOutRequest | USB_REQ_CLEAR_FEATURE:
    656	case EndpointOutRequest | USB_REQ_SET_FEATURE:
    657		dev_dbg (hcd->self.controller, "no endpoint features yet\n");
    658		break;
    659
    660	/* CLASS REQUESTS (and errors) */
    661
    662	default:
    663nongeneric:
    664		/* non-generic request */
    665		switch (typeReq) {
    666		case GetHubStatus:
    667			len = 4;
    668			break;
    669		case GetPortStatus:
    670			if (wValue == HUB_PORT_STATUS)
    671				len = 4;
    672			else
    673				/* other port status types return 8 bytes */
    674				len = 8;
    675			break;
    676		case GetHubDescriptor:
    677			len = sizeof (struct usb_hub_descriptor);
    678			break;
    679		case DeviceRequest | USB_REQ_GET_DESCRIPTOR:
    680			/* len is returned by hub_control */
    681			break;
    682		}
    683		status = hcd->driver->hub_control (hcd,
    684			typeReq, wValue, wIndex,
    685			tbuf, wLength);
    686
    687		if (typeReq == GetHubDescriptor)
    688			usb_hub_adjust_deviceremovable(hcd->self.root_hub,
    689				(struct usb_hub_descriptor *)tbuf);
    690		break;
    691error:
    692		/* "protocol stall" on error */
    693		status = -EPIPE;
    694	}
    695
    696	if (status < 0) {
    697		len = 0;
    698		if (status != -EPIPE) {
    699			dev_dbg (hcd->self.controller,
    700				"CTRL: TypeReq=0x%x val=0x%x "
    701				"idx=0x%x len=%d ==> %d\n",
    702				typeReq, wValue, wIndex,
    703				wLength, status);
    704		}
    705	} else if (status > 0) {
    706		/* hub_control may return the length of data copied. */
    707		len = status;
    708		status = 0;
    709	}
    710	if (len) {
    711		if (urb->transfer_buffer_length < len)
    712			len = urb->transfer_buffer_length;
    713		urb->actual_length = len;
    714		/* always USB_DIR_IN, toward host */
    715		memcpy (ubuf, bufp, len);
    716
    717		/* report whether RH hardware supports remote wakeup */
    718		if (patch_wakeup &&
    719				len > offsetof (struct usb_config_descriptor,
    720						bmAttributes))
    721			((struct usb_config_descriptor *)ubuf)->bmAttributes
    722				|= USB_CONFIG_ATT_WAKEUP;
    723
    724		/* report whether RH hardware has an integrated TT */
    725		if (patch_protocol &&
    726				len > offsetof(struct usb_device_descriptor,
    727						bDeviceProtocol))
    728			((struct usb_device_descriptor *) ubuf)->
    729				bDeviceProtocol = USB_HUB_PR_HS_SINGLE_TT;
    730	}
    731
    732	kfree(tbuf);
    733 err_alloc:
    734
    735	/* any errors get returned through the urb completion */
    736	spin_lock_irq(&hcd_root_hub_lock);
    737	usb_hcd_unlink_urb_from_ep(hcd, urb);
    738	usb_hcd_giveback_urb(hcd, urb, status);
    739	spin_unlock_irq(&hcd_root_hub_lock);
    740	return 0;
    741}
    742
    743/*-------------------------------------------------------------------------*/
    744
    745/*
    746 * Root Hub interrupt transfers are polled using a timer if the
    747 * driver requests it; otherwise the driver is responsible for
    748 * calling usb_hcd_poll_rh_status() when an event occurs.
    749 *
    750 * Completion handler may not sleep. See usb_hcd_giveback_urb() for details.
    751 */
    752void usb_hcd_poll_rh_status(struct usb_hcd *hcd)
    753{
    754	struct urb	*urb;
    755	int		length;
    756	int		status;
    757	unsigned long	flags;
    758	char		buffer[6];	/* Any root hubs with > 31 ports? */
    759
    760	if (unlikely(!hcd->rh_pollable))
    761		return;
    762	if (!hcd->uses_new_polling && !hcd->status_urb)
    763		return;
    764
    765	length = hcd->driver->hub_status_data(hcd, buffer);
    766	if (length > 0) {
    767
    768		/* try to complete the status urb */
    769		spin_lock_irqsave(&hcd_root_hub_lock, flags);
    770		urb = hcd->status_urb;
    771		if (urb) {
    772			clear_bit(HCD_FLAG_POLL_PENDING, &hcd->flags);
    773			hcd->status_urb = NULL;
    774			if (urb->transfer_buffer_length >= length) {
    775				status = 0;
    776			} else {
    777				status = -EOVERFLOW;
    778				length = urb->transfer_buffer_length;
    779			}
    780			urb->actual_length = length;
    781			memcpy(urb->transfer_buffer, buffer, length);
    782
    783			usb_hcd_unlink_urb_from_ep(hcd, urb);
    784			usb_hcd_giveback_urb(hcd, urb, status);
    785		} else {
    786			length = 0;
    787			set_bit(HCD_FLAG_POLL_PENDING, &hcd->flags);
    788		}
    789		spin_unlock_irqrestore(&hcd_root_hub_lock, flags);
    790	}
    791
    792	/* The USB 2.0 spec says 256 ms.  This is close enough and won't
    793	 * exceed that limit if HZ is 100. The math is more clunky than
    794	 * maybe expected, this is to make sure that all timers for USB devices
    795	 * fire at the same time to give the CPU a break in between */
    796	if (hcd->uses_new_polling ? HCD_POLL_RH(hcd) :
    797			(length == 0 && hcd->status_urb != NULL))
    798		mod_timer (&hcd->rh_timer, (jiffies/(HZ/4) + 1) * (HZ/4));
    799}
    800EXPORT_SYMBOL_GPL(usb_hcd_poll_rh_status);
    801
    802/* timer callback */
    803static void rh_timer_func (struct timer_list *t)
    804{
    805	struct usb_hcd *_hcd = from_timer(_hcd, t, rh_timer);
    806
    807	usb_hcd_poll_rh_status(_hcd);
    808}
    809
    810/*-------------------------------------------------------------------------*/
    811
    812static int rh_queue_status (struct usb_hcd *hcd, struct urb *urb)
    813{
    814	int		retval;
    815	unsigned long	flags;
    816	unsigned	len = 1 + (urb->dev->maxchild / 8);
    817
    818	spin_lock_irqsave (&hcd_root_hub_lock, flags);
    819	if (hcd->status_urb || urb->transfer_buffer_length < len) {
    820		dev_dbg (hcd->self.controller, "not queuing rh status urb\n");
    821		retval = -EINVAL;
    822		goto done;
    823	}
    824
    825	retval = usb_hcd_link_urb_to_ep(hcd, urb);
    826	if (retval)
    827		goto done;
    828
    829	hcd->status_urb = urb;
    830	urb->hcpriv = hcd;	/* indicate it's queued */
    831	if (!hcd->uses_new_polling)
    832		mod_timer(&hcd->rh_timer, (jiffies/(HZ/4) + 1) * (HZ/4));
    833
    834	/* If a status change has already occurred, report it ASAP */
    835	else if (HCD_POLL_PENDING(hcd))
    836		mod_timer(&hcd->rh_timer, jiffies);
    837	retval = 0;
    838 done:
    839	spin_unlock_irqrestore (&hcd_root_hub_lock, flags);
    840	return retval;
    841}
    842
    843static int rh_urb_enqueue (struct usb_hcd *hcd, struct urb *urb)
    844{
    845	if (usb_endpoint_xfer_int(&urb->ep->desc))
    846		return rh_queue_status (hcd, urb);
    847	if (usb_endpoint_xfer_control(&urb->ep->desc))
    848		return rh_call_control (hcd, urb);
    849	return -EINVAL;
    850}
    851
    852/*-------------------------------------------------------------------------*/
    853
    854/* Unlinks of root-hub control URBs are legal, but they don't do anything
    855 * since these URBs always execute synchronously.
    856 */
    857static int usb_rh_urb_dequeue(struct usb_hcd *hcd, struct urb *urb, int status)
    858{
    859	unsigned long	flags;
    860	int		rc;
    861
    862	spin_lock_irqsave(&hcd_root_hub_lock, flags);
    863	rc = usb_hcd_check_unlink_urb(hcd, urb, status);
    864	if (rc)
    865		goto done;
    866
    867	if (usb_endpoint_num(&urb->ep->desc) == 0) {	/* Control URB */
    868		;	/* Do nothing */
    869
    870	} else {				/* Status URB */
    871		if (!hcd->uses_new_polling)
    872			del_timer (&hcd->rh_timer);
    873		if (urb == hcd->status_urb) {
    874			hcd->status_urb = NULL;
    875			usb_hcd_unlink_urb_from_ep(hcd, urb);
    876			usb_hcd_giveback_urb(hcd, urb, status);
    877		}
    878	}
    879 done:
    880	spin_unlock_irqrestore(&hcd_root_hub_lock, flags);
    881	return rc;
    882}
    883
    884
    885/*-------------------------------------------------------------------------*/
    886
    887/**
    888 * usb_bus_init - shared initialization code
    889 * @bus: the bus structure being initialized
    890 *
    891 * This code is used to initialize a usb_bus structure, memory for which is
    892 * separately managed.
    893 */
    894static void usb_bus_init (struct usb_bus *bus)
    895{
    896	memset (&bus->devmap, 0, sizeof(struct usb_devmap));
    897
    898	bus->devnum_next = 1;
    899
    900	bus->root_hub = NULL;
    901	bus->busnum = -1;
    902	bus->bandwidth_allocated = 0;
    903	bus->bandwidth_int_reqs  = 0;
    904	bus->bandwidth_isoc_reqs = 0;
    905	mutex_init(&bus->devnum_next_mutex);
    906}
    907
    908/*-------------------------------------------------------------------------*/
    909
    910/**
    911 * usb_register_bus - registers the USB host controller with the usb core
    912 * @bus: pointer to the bus to register
    913 *
    914 * Context: task context, might sleep.
    915 *
    916 * Assigns a bus number, and links the controller into usbcore data
    917 * structures so that it can be seen by scanning the bus list.
    918 *
    919 * Return: 0 if successful. A negative error code otherwise.
    920 */
    921static int usb_register_bus(struct usb_bus *bus)
    922{
    923	int result = -E2BIG;
    924	int busnum;
    925
    926	mutex_lock(&usb_bus_idr_lock);
    927	busnum = idr_alloc(&usb_bus_idr, bus, 1, USB_MAXBUS, GFP_KERNEL);
    928	if (busnum < 0) {
    929		pr_err("%s: failed to get bus number\n", usbcore_name);
    930		goto error_find_busnum;
    931	}
    932	bus->busnum = busnum;
    933	mutex_unlock(&usb_bus_idr_lock);
    934
    935	usb_notify_add_bus(bus);
    936
    937	dev_info (bus->controller, "new USB bus registered, assigned bus "
    938		  "number %d\n", bus->busnum);
    939	return 0;
    940
    941error_find_busnum:
    942	mutex_unlock(&usb_bus_idr_lock);
    943	return result;
    944}
    945
    946/**
    947 * usb_deregister_bus - deregisters the USB host controller
    948 * @bus: pointer to the bus to deregister
    949 *
    950 * Context: task context, might sleep.
    951 *
    952 * Recycles the bus number, and unlinks the controller from usbcore data
    953 * structures so that it won't be seen by scanning the bus list.
    954 */
    955static void usb_deregister_bus (struct usb_bus *bus)
    956{
    957	dev_info (bus->controller, "USB bus %d deregistered\n", bus->busnum);
    958
    959	/*
    960	 * NOTE: make sure that all the devices are removed by the
    961	 * controller code, as well as having it call this when cleaning
    962	 * itself up
    963	 */
    964	mutex_lock(&usb_bus_idr_lock);
    965	idr_remove(&usb_bus_idr, bus->busnum);
    966	mutex_unlock(&usb_bus_idr_lock);
    967
    968	usb_notify_remove_bus(bus);
    969}
    970
    971/**
    972 * register_root_hub - called by usb_add_hcd() to register a root hub
    973 * @hcd: host controller for this root hub
    974 *
    975 * This function registers the root hub with the USB subsystem.  It sets up
    976 * the device properly in the device tree and then calls usb_new_device()
    977 * to register the usb device.  It also assigns the root hub's USB address
    978 * (always 1).
    979 *
    980 * Return: 0 if successful. A negative error code otherwise.
    981 */
    982static int register_root_hub(struct usb_hcd *hcd)
    983{
    984	struct device *parent_dev = hcd->self.controller;
    985	struct usb_device *usb_dev = hcd->self.root_hub;
    986	const int devnum = 1;
    987	int retval;
    988
    989	usb_dev->devnum = devnum;
    990	usb_dev->bus->devnum_next = devnum + 1;
    991	set_bit (devnum, usb_dev->bus->devmap.devicemap);
    992	usb_set_device_state(usb_dev, USB_STATE_ADDRESS);
    993
    994	mutex_lock(&usb_bus_idr_lock);
    995
    996	usb_dev->ep0.desc.wMaxPacketSize = cpu_to_le16(64);
    997	retval = usb_get_device_descriptor(usb_dev, USB_DT_DEVICE_SIZE);
    998	if (retval != sizeof usb_dev->descriptor) {
    999		mutex_unlock(&usb_bus_idr_lock);
   1000		dev_dbg (parent_dev, "can't read %s device descriptor %d\n",
   1001				dev_name(&usb_dev->dev), retval);
   1002		return (retval < 0) ? retval : -EMSGSIZE;
   1003	}
   1004
   1005	if (le16_to_cpu(usb_dev->descriptor.bcdUSB) >= 0x0201) {
   1006		retval = usb_get_bos_descriptor(usb_dev);
   1007		if (!retval) {
   1008			usb_dev->lpm_capable = usb_device_supports_lpm(usb_dev);
   1009		} else if (usb_dev->speed >= USB_SPEED_SUPER) {
   1010			mutex_unlock(&usb_bus_idr_lock);
   1011			dev_dbg(parent_dev, "can't read %s bos descriptor %d\n",
   1012					dev_name(&usb_dev->dev), retval);
   1013			return retval;
   1014		}
   1015	}
   1016
   1017	retval = usb_new_device (usb_dev);
   1018	if (retval) {
   1019		dev_err (parent_dev, "can't register root hub for %s, %d\n",
   1020				dev_name(&usb_dev->dev), retval);
   1021	} else {
   1022		spin_lock_irq (&hcd_root_hub_lock);
   1023		hcd->rh_registered = 1;
   1024		spin_unlock_irq (&hcd_root_hub_lock);
   1025
   1026		/* Did the HC die before the root hub was registered? */
   1027		if (HCD_DEAD(hcd))
   1028			usb_hc_died (hcd);	/* This time clean up */
   1029	}
   1030	mutex_unlock(&usb_bus_idr_lock);
   1031
   1032	return retval;
   1033}
   1034
   1035/*
   1036 * usb_hcd_start_port_resume - a root-hub port is sending a resume signal
   1037 * @bus: the bus which the root hub belongs to
   1038 * @portnum: the port which is being resumed
   1039 *
   1040 * HCDs should call this function when they know that a resume signal is
   1041 * being sent to a root-hub port.  The root hub will be prevented from
   1042 * going into autosuspend until usb_hcd_end_port_resume() is called.
   1043 *
   1044 * The bus's private lock must be held by the caller.
   1045 */
   1046void usb_hcd_start_port_resume(struct usb_bus *bus, int portnum)
   1047{
   1048	unsigned bit = 1 << portnum;
   1049
   1050	if (!(bus->resuming_ports & bit)) {
   1051		bus->resuming_ports |= bit;
   1052		pm_runtime_get_noresume(&bus->root_hub->dev);
   1053	}
   1054}
   1055EXPORT_SYMBOL_GPL(usb_hcd_start_port_resume);
   1056
   1057/*
   1058 * usb_hcd_end_port_resume - a root-hub port has stopped sending a resume signal
   1059 * @bus: the bus which the root hub belongs to
   1060 * @portnum: the port which is being resumed
   1061 *
   1062 * HCDs should call this function when they know that a resume signal has
   1063 * stopped being sent to a root-hub port.  The root hub will be allowed to
   1064 * autosuspend again.
   1065 *
   1066 * The bus's private lock must be held by the caller.
   1067 */
   1068void usb_hcd_end_port_resume(struct usb_bus *bus, int portnum)
   1069{
   1070	unsigned bit = 1 << portnum;
   1071
   1072	if (bus->resuming_ports & bit) {
   1073		bus->resuming_ports &= ~bit;
   1074		pm_runtime_put_noidle(&bus->root_hub->dev);
   1075	}
   1076}
   1077EXPORT_SYMBOL_GPL(usb_hcd_end_port_resume);
   1078
   1079/*-------------------------------------------------------------------------*/
   1080
   1081/**
   1082 * usb_calc_bus_time - approximate periodic transaction time in nanoseconds
   1083 * @speed: from dev->speed; USB_SPEED_{LOW,FULL,HIGH}
   1084 * @is_input: true iff the transaction sends data to the host
   1085 * @isoc: true for isochronous transactions, false for interrupt ones
   1086 * @bytecount: how many bytes in the transaction.
   1087 *
   1088 * Return: Approximate bus time in nanoseconds for a periodic transaction.
   1089 *
   1090 * Note:
   1091 * See USB 2.0 spec section 5.11.3; only periodic transfers need to be
   1092 * scheduled in software, this function is only used for such scheduling.
   1093 */
   1094long usb_calc_bus_time (int speed, int is_input, int isoc, int bytecount)
   1095{
   1096	unsigned long	tmp;
   1097
   1098	switch (speed) {
   1099	case USB_SPEED_LOW: 	/* INTR only */
   1100		if (is_input) {
   1101			tmp = (67667L * (31L + 10L * BitTime (bytecount))) / 1000L;
   1102			return 64060L + (2 * BW_HUB_LS_SETUP) + BW_HOST_DELAY + tmp;
   1103		} else {
   1104			tmp = (66700L * (31L + 10L * BitTime (bytecount))) / 1000L;
   1105			return 64107L + (2 * BW_HUB_LS_SETUP) + BW_HOST_DELAY + tmp;
   1106		}
   1107	case USB_SPEED_FULL:	/* ISOC or INTR */
   1108		if (isoc) {
   1109			tmp = (8354L * (31L + 10L * BitTime (bytecount))) / 1000L;
   1110			return ((is_input) ? 7268L : 6265L) + BW_HOST_DELAY + tmp;
   1111		} else {
   1112			tmp = (8354L * (31L + 10L * BitTime (bytecount))) / 1000L;
   1113			return 9107L + BW_HOST_DELAY + tmp;
   1114		}
   1115	case USB_SPEED_HIGH:	/* ISOC or INTR */
   1116		/* FIXME adjust for input vs output */
   1117		if (isoc)
   1118			tmp = HS_NSECS_ISO (bytecount);
   1119		else
   1120			tmp = HS_NSECS (bytecount);
   1121		return tmp;
   1122	default:
   1123		pr_debug ("%s: bogus device speed!\n", usbcore_name);
   1124		return -1;
   1125	}
   1126}
   1127EXPORT_SYMBOL_GPL(usb_calc_bus_time);
   1128
   1129
   1130/*-------------------------------------------------------------------------*/
   1131
   1132/*
   1133 * Generic HC operations.
   1134 */
   1135
   1136/*-------------------------------------------------------------------------*/
   1137
   1138/**
   1139 * usb_hcd_link_urb_to_ep - add an URB to its endpoint queue
   1140 * @hcd: host controller to which @urb was submitted
   1141 * @urb: URB being submitted
   1142 *
   1143 * Host controller drivers should call this routine in their enqueue()
   1144 * method.  The HCD's private spinlock must be held and interrupts must
   1145 * be disabled.  The actions carried out here are required for URB
   1146 * submission, as well as for endpoint shutdown and for usb_kill_urb.
   1147 *
   1148 * Return: 0 for no error, otherwise a negative error code (in which case
   1149 * the enqueue() method must fail).  If no error occurs but enqueue() fails
   1150 * anyway, it must call usb_hcd_unlink_urb_from_ep() before releasing
   1151 * the private spinlock and returning.
   1152 */
   1153int usb_hcd_link_urb_to_ep(struct usb_hcd *hcd, struct urb *urb)
   1154{
   1155	int		rc = 0;
   1156
   1157	spin_lock(&hcd_urb_list_lock);
   1158
   1159	/* Check that the URB isn't being killed */
   1160	if (unlikely(atomic_read(&urb->reject))) {
   1161		rc = -EPERM;
   1162		goto done;
   1163	}
   1164
   1165	if (unlikely(!urb->ep->enabled)) {
   1166		rc = -ENOENT;
   1167		goto done;
   1168	}
   1169
   1170	if (unlikely(!urb->dev->can_submit)) {
   1171		rc = -EHOSTUNREACH;
   1172		goto done;
   1173	}
   1174
   1175	/*
   1176	 * Check the host controller's state and add the URB to the
   1177	 * endpoint's queue.
   1178	 */
   1179	if (HCD_RH_RUNNING(hcd)) {
   1180		urb->unlinked = 0;
   1181		list_add_tail(&urb->urb_list, &urb->ep->urb_list);
   1182	} else {
   1183		rc = -ESHUTDOWN;
   1184		goto done;
   1185	}
   1186 done:
   1187	spin_unlock(&hcd_urb_list_lock);
   1188	return rc;
   1189}
   1190EXPORT_SYMBOL_GPL(usb_hcd_link_urb_to_ep);
   1191
   1192/**
   1193 * usb_hcd_check_unlink_urb - check whether an URB may be unlinked
   1194 * @hcd: host controller to which @urb was submitted
   1195 * @urb: URB being checked for unlinkability
   1196 * @status: error code to store in @urb if the unlink succeeds
   1197 *
   1198 * Host controller drivers should call this routine in their dequeue()
   1199 * method.  The HCD's private spinlock must be held and interrupts must
   1200 * be disabled.  The actions carried out here are required for making
   1201 * sure than an unlink is valid.
   1202 *
   1203 * Return: 0 for no error, otherwise a negative error code (in which case
   1204 * the dequeue() method must fail).  The possible error codes are:
   1205 *
   1206 *	-EIDRM: @urb was not submitted or has already completed.
   1207 *		The completion function may not have been called yet.
   1208 *
   1209 *	-EBUSY: @urb has already been unlinked.
   1210 */
   1211int usb_hcd_check_unlink_urb(struct usb_hcd *hcd, struct urb *urb,
   1212		int status)
   1213{
   1214	struct list_head	*tmp;
   1215
   1216	/* insist the urb is still queued */
   1217	list_for_each(tmp, &urb->ep->urb_list) {
   1218		if (tmp == &urb->urb_list)
   1219			break;
   1220	}
   1221	if (tmp != &urb->urb_list)
   1222		return -EIDRM;
   1223
   1224	/* Any status except -EINPROGRESS means something already started to
   1225	 * unlink this URB from the hardware.  So there's no more work to do.
   1226	 */
   1227	if (urb->unlinked)
   1228		return -EBUSY;
   1229	urb->unlinked = status;
   1230	return 0;
   1231}
   1232EXPORT_SYMBOL_GPL(usb_hcd_check_unlink_urb);
   1233
   1234/**
   1235 * usb_hcd_unlink_urb_from_ep - remove an URB from its endpoint queue
   1236 * @hcd: host controller to which @urb was submitted
   1237 * @urb: URB being unlinked
   1238 *
   1239 * Host controller drivers should call this routine before calling
   1240 * usb_hcd_giveback_urb().  The HCD's private spinlock must be held and
   1241 * interrupts must be disabled.  The actions carried out here are required
   1242 * for URB completion.
   1243 */
   1244void usb_hcd_unlink_urb_from_ep(struct usb_hcd *hcd, struct urb *urb)
   1245{
   1246	/* clear all state linking urb to this dev (and hcd) */
   1247	spin_lock(&hcd_urb_list_lock);
   1248	list_del_init(&urb->urb_list);
   1249	spin_unlock(&hcd_urb_list_lock);
   1250}
   1251EXPORT_SYMBOL_GPL(usb_hcd_unlink_urb_from_ep);
   1252
   1253/*
   1254 * Some usb host controllers can only perform dma using a small SRAM area.
   1255 * The usb core itself is however optimized for host controllers that can dma
   1256 * using regular system memory - like pci devices doing bus mastering.
   1257 *
   1258 * To support host controllers with limited dma capabilities we provide dma
   1259 * bounce buffers. This feature can be enabled by initializing
   1260 * hcd->localmem_pool using usb_hcd_setup_local_mem().
   1261 *
   1262 * The initialized hcd->localmem_pool then tells the usb code to allocate all
   1263 * data for dma using the genalloc API.
   1264 *
   1265 * So, to summarize...
   1266 *
   1267 * - We need "local" memory, canonical example being
   1268 *   a small SRAM on a discrete controller being the
   1269 *   only memory that the controller can read ...
   1270 *   (a) "normal" kernel memory is no good, and
   1271 *   (b) there's not enough to share
   1272 *
   1273 * - So we use that, even though the primary requirement
   1274 *   is that the memory be "local" (hence addressable
   1275 *   by that device), not "coherent".
   1276 *
   1277 */
   1278
   1279static int hcd_alloc_coherent(struct usb_bus *bus,
   1280			      gfp_t mem_flags, dma_addr_t *dma_handle,
   1281			      void **vaddr_handle, size_t size,
   1282			      enum dma_data_direction dir)
   1283{
   1284	unsigned char *vaddr;
   1285
   1286	if (*vaddr_handle == NULL) {
   1287		WARN_ON_ONCE(1);
   1288		return -EFAULT;
   1289	}
   1290
   1291	vaddr = hcd_buffer_alloc(bus, size + sizeof(unsigned long),
   1292				 mem_flags, dma_handle);
   1293	if (!vaddr)
   1294		return -ENOMEM;
   1295
   1296	/*
   1297	 * Store the virtual address of the buffer at the end
   1298	 * of the allocated dma buffer. The size of the buffer
   1299	 * may be uneven so use unaligned functions instead
   1300	 * of just rounding up. It makes sense to optimize for
   1301	 * memory footprint over access speed since the amount
   1302	 * of memory available for dma may be limited.
   1303	 */
   1304	put_unaligned((unsigned long)*vaddr_handle,
   1305		      (unsigned long *)(vaddr + size));
   1306
   1307	if (dir == DMA_TO_DEVICE)
   1308		memcpy(vaddr, *vaddr_handle, size);
   1309
   1310	*vaddr_handle = vaddr;
   1311	return 0;
   1312}
   1313
   1314static void hcd_free_coherent(struct usb_bus *bus, dma_addr_t *dma_handle,
   1315			      void **vaddr_handle, size_t size,
   1316			      enum dma_data_direction dir)
   1317{
   1318	unsigned char *vaddr = *vaddr_handle;
   1319
   1320	vaddr = (void *)get_unaligned((unsigned long *)(vaddr + size));
   1321
   1322	if (dir == DMA_FROM_DEVICE)
   1323		memcpy(vaddr, *vaddr_handle, size);
   1324
   1325	hcd_buffer_free(bus, size + sizeof(vaddr), *vaddr_handle, *dma_handle);
   1326
   1327	*vaddr_handle = vaddr;
   1328	*dma_handle = 0;
   1329}
   1330
   1331void usb_hcd_unmap_urb_setup_for_dma(struct usb_hcd *hcd, struct urb *urb)
   1332{
   1333	if (IS_ENABLED(CONFIG_HAS_DMA) &&
   1334	    (urb->transfer_flags & URB_SETUP_MAP_SINGLE))
   1335		dma_unmap_single(hcd->self.sysdev,
   1336				urb->setup_dma,
   1337				sizeof(struct usb_ctrlrequest),
   1338				DMA_TO_DEVICE);
   1339	else if (urb->transfer_flags & URB_SETUP_MAP_LOCAL)
   1340		hcd_free_coherent(urb->dev->bus,
   1341				&urb->setup_dma,
   1342				(void **) &urb->setup_packet,
   1343				sizeof(struct usb_ctrlrequest),
   1344				DMA_TO_DEVICE);
   1345
   1346	/* Make it safe to call this routine more than once */
   1347	urb->transfer_flags &= ~(URB_SETUP_MAP_SINGLE | URB_SETUP_MAP_LOCAL);
   1348}
   1349EXPORT_SYMBOL_GPL(usb_hcd_unmap_urb_setup_for_dma);
   1350
   1351static void unmap_urb_for_dma(struct usb_hcd *hcd, struct urb *urb)
   1352{
   1353	if (hcd->driver->unmap_urb_for_dma)
   1354		hcd->driver->unmap_urb_for_dma(hcd, urb);
   1355	else
   1356		usb_hcd_unmap_urb_for_dma(hcd, urb);
   1357}
   1358
   1359void usb_hcd_unmap_urb_for_dma(struct usb_hcd *hcd, struct urb *urb)
   1360{
   1361	enum dma_data_direction dir;
   1362
   1363	usb_hcd_unmap_urb_setup_for_dma(hcd, urb);
   1364
   1365	dir = usb_urb_dir_in(urb) ? DMA_FROM_DEVICE : DMA_TO_DEVICE;
   1366	if (IS_ENABLED(CONFIG_HAS_DMA) &&
   1367	    (urb->transfer_flags & URB_DMA_MAP_SG))
   1368		dma_unmap_sg(hcd->self.sysdev,
   1369				urb->sg,
   1370				urb->num_sgs,
   1371				dir);
   1372	else if (IS_ENABLED(CONFIG_HAS_DMA) &&
   1373		 (urb->transfer_flags & URB_DMA_MAP_PAGE))
   1374		dma_unmap_page(hcd->self.sysdev,
   1375				urb->transfer_dma,
   1376				urb->transfer_buffer_length,
   1377				dir);
   1378	else if (IS_ENABLED(CONFIG_HAS_DMA) &&
   1379		 (urb->transfer_flags & URB_DMA_MAP_SINGLE))
   1380		dma_unmap_single(hcd->self.sysdev,
   1381				urb->transfer_dma,
   1382				urb->transfer_buffer_length,
   1383				dir);
   1384	else if (urb->transfer_flags & URB_MAP_LOCAL)
   1385		hcd_free_coherent(urb->dev->bus,
   1386				&urb->transfer_dma,
   1387				&urb->transfer_buffer,
   1388				urb->transfer_buffer_length,
   1389				dir);
   1390
   1391	/* Make it safe to call this routine more than once */
   1392	urb->transfer_flags &= ~(URB_DMA_MAP_SG | URB_DMA_MAP_PAGE |
   1393			URB_DMA_MAP_SINGLE | URB_MAP_LOCAL);
   1394}
   1395EXPORT_SYMBOL_GPL(usb_hcd_unmap_urb_for_dma);
   1396
   1397static int map_urb_for_dma(struct usb_hcd *hcd, struct urb *urb,
   1398			   gfp_t mem_flags)
   1399{
   1400	if (hcd->driver->map_urb_for_dma)
   1401		return hcd->driver->map_urb_for_dma(hcd, urb, mem_flags);
   1402	else
   1403		return usb_hcd_map_urb_for_dma(hcd, urb, mem_flags);
   1404}
   1405
   1406int usb_hcd_map_urb_for_dma(struct usb_hcd *hcd, struct urb *urb,
   1407			    gfp_t mem_flags)
   1408{
   1409	enum dma_data_direction dir;
   1410	int ret = 0;
   1411
   1412	/* Map the URB's buffers for DMA access.
   1413	 * Lower level HCD code should use *_dma exclusively,
   1414	 * unless it uses pio or talks to another transport,
   1415	 * or uses the provided scatter gather list for bulk.
   1416	 */
   1417
   1418	if (usb_endpoint_xfer_control(&urb->ep->desc)) {
   1419		if (hcd->self.uses_pio_for_control)
   1420			return ret;
   1421		if (hcd->localmem_pool) {
   1422			ret = hcd_alloc_coherent(
   1423					urb->dev->bus, mem_flags,
   1424					&urb->setup_dma,
   1425					(void **)&urb->setup_packet,
   1426					sizeof(struct usb_ctrlrequest),
   1427					DMA_TO_DEVICE);
   1428			if (ret)
   1429				return ret;
   1430			urb->transfer_flags |= URB_SETUP_MAP_LOCAL;
   1431		} else if (hcd_uses_dma(hcd)) {
   1432			if (object_is_on_stack(urb->setup_packet)) {
   1433				WARN_ONCE(1, "setup packet is on stack\n");
   1434				return -EAGAIN;
   1435			}
   1436
   1437			urb->setup_dma = dma_map_single(
   1438					hcd->self.sysdev,
   1439					urb->setup_packet,
   1440					sizeof(struct usb_ctrlrequest),
   1441					DMA_TO_DEVICE);
   1442			if (dma_mapping_error(hcd->self.sysdev,
   1443						urb->setup_dma))
   1444				return -EAGAIN;
   1445			urb->transfer_flags |= URB_SETUP_MAP_SINGLE;
   1446		}
   1447	}
   1448
   1449	dir = usb_urb_dir_in(urb) ? DMA_FROM_DEVICE : DMA_TO_DEVICE;
   1450	if (urb->transfer_buffer_length != 0
   1451	    && !(urb->transfer_flags & URB_NO_TRANSFER_DMA_MAP)) {
   1452		if (hcd->localmem_pool) {
   1453			ret = hcd_alloc_coherent(
   1454					urb->dev->bus, mem_flags,
   1455					&urb->transfer_dma,
   1456					&urb->transfer_buffer,
   1457					urb->transfer_buffer_length,
   1458					dir);
   1459			if (ret == 0)
   1460				urb->transfer_flags |= URB_MAP_LOCAL;
   1461		} else if (hcd_uses_dma(hcd)) {
   1462			if (urb->num_sgs) {
   1463				int n;
   1464
   1465				/* We don't support sg for isoc transfers ! */
   1466				if (usb_endpoint_xfer_isoc(&urb->ep->desc)) {
   1467					WARN_ON(1);
   1468					return -EINVAL;
   1469				}
   1470
   1471				n = dma_map_sg(
   1472						hcd->self.sysdev,
   1473						urb->sg,
   1474						urb->num_sgs,
   1475						dir);
   1476				if (n <= 0)
   1477					ret = -EAGAIN;
   1478				else
   1479					urb->transfer_flags |= URB_DMA_MAP_SG;
   1480				urb->num_mapped_sgs = n;
   1481				if (n != urb->num_sgs)
   1482					urb->transfer_flags |=
   1483							URB_DMA_SG_COMBINED;
   1484			} else if (urb->sg) {
   1485				struct scatterlist *sg = urb->sg;
   1486				urb->transfer_dma = dma_map_page(
   1487						hcd->self.sysdev,
   1488						sg_page(sg),
   1489						sg->offset,
   1490						urb->transfer_buffer_length,
   1491						dir);
   1492				if (dma_mapping_error(hcd->self.sysdev,
   1493						urb->transfer_dma))
   1494					ret = -EAGAIN;
   1495				else
   1496					urb->transfer_flags |= URB_DMA_MAP_PAGE;
   1497			} else if (object_is_on_stack(urb->transfer_buffer)) {
   1498				WARN_ONCE(1, "transfer buffer is on stack\n");
   1499				ret = -EAGAIN;
   1500			} else {
   1501				urb->transfer_dma = dma_map_single(
   1502						hcd->self.sysdev,
   1503						urb->transfer_buffer,
   1504						urb->transfer_buffer_length,
   1505						dir);
   1506				if (dma_mapping_error(hcd->self.sysdev,
   1507						urb->transfer_dma))
   1508					ret = -EAGAIN;
   1509				else
   1510					urb->transfer_flags |= URB_DMA_MAP_SINGLE;
   1511			}
   1512		}
   1513		if (ret && (urb->transfer_flags & (URB_SETUP_MAP_SINGLE |
   1514				URB_SETUP_MAP_LOCAL)))
   1515			usb_hcd_unmap_urb_for_dma(hcd, urb);
   1516	}
   1517	return ret;
   1518}
   1519EXPORT_SYMBOL_GPL(usb_hcd_map_urb_for_dma);
   1520
   1521/*-------------------------------------------------------------------------*/
   1522
   1523/* may be called in any context with a valid urb->dev usecount
   1524 * caller surrenders "ownership" of urb
   1525 * expects usb_submit_urb() to have sanity checked and conditioned all
   1526 * inputs in the urb
   1527 */
   1528int usb_hcd_submit_urb (struct urb *urb, gfp_t mem_flags)
   1529{
   1530	int			status;
   1531	struct usb_hcd		*hcd = bus_to_hcd(urb->dev->bus);
   1532
   1533	/* increment urb's reference count as part of giving it to the HCD
   1534	 * (which will control it).  HCD guarantees that it either returns
   1535	 * an error or calls giveback(), but not both.
   1536	 */
   1537	usb_get_urb(urb);
   1538	atomic_inc(&urb->use_count);
   1539	atomic_inc(&urb->dev->urbnum);
   1540	usbmon_urb_submit(&hcd->self, urb);
   1541
   1542	/* NOTE requirements on root-hub callers (usbfs and the hub
   1543	 * driver, for now):  URBs' urb->transfer_buffer must be
   1544	 * valid and usb_buffer_{sync,unmap}() not be needed, since
   1545	 * they could clobber root hub response data.  Also, control
   1546	 * URBs must be submitted in process context with interrupts
   1547	 * enabled.
   1548	 */
   1549
   1550	if (is_root_hub(urb->dev)) {
   1551		status = rh_urb_enqueue(hcd, urb);
   1552	} else {
   1553		status = map_urb_for_dma(hcd, urb, mem_flags);
   1554		if (likely(status == 0)) {
   1555			status = hcd->driver->urb_enqueue(hcd, urb, mem_flags);
   1556			if (unlikely(status))
   1557				unmap_urb_for_dma(hcd, urb);
   1558		}
   1559	}
   1560
   1561	if (unlikely(status)) {
   1562		usbmon_urb_submit_error(&hcd->self, urb, status);
   1563		urb->hcpriv = NULL;
   1564		INIT_LIST_HEAD(&urb->urb_list);
   1565		atomic_dec(&urb->use_count);
   1566		/*
   1567		 * Order the write of urb->use_count above before the read
   1568		 * of urb->reject below.  Pairs with the memory barriers in
   1569		 * usb_kill_urb() and usb_poison_urb().
   1570		 */
   1571		smp_mb__after_atomic();
   1572
   1573		atomic_dec(&urb->dev->urbnum);
   1574		if (atomic_read(&urb->reject))
   1575			wake_up(&usb_kill_urb_queue);
   1576		usb_put_urb(urb);
   1577	}
   1578	return status;
   1579}
   1580
   1581/*-------------------------------------------------------------------------*/
   1582
   1583/* this makes the hcd giveback() the urb more quickly, by kicking it
   1584 * off hardware queues (which may take a while) and returning it as
   1585 * soon as practical.  we've already set up the urb's return status,
   1586 * but we can't know if the callback completed already.
   1587 */
   1588static int unlink1(struct usb_hcd *hcd, struct urb *urb, int status)
   1589{
   1590	int		value;
   1591
   1592	if (is_root_hub(urb->dev))
   1593		value = usb_rh_urb_dequeue(hcd, urb, status);
   1594	else {
   1595
   1596		/* The only reason an HCD might fail this call is if
   1597		 * it has not yet fully queued the urb to begin with.
   1598		 * Such failures should be harmless. */
   1599		value = hcd->driver->urb_dequeue(hcd, urb, status);
   1600	}
   1601	return value;
   1602}
   1603
   1604/*
   1605 * called in any context
   1606 *
   1607 * caller guarantees urb won't be recycled till both unlink()
   1608 * and the urb's completion function return
   1609 */
   1610int usb_hcd_unlink_urb (struct urb *urb, int status)
   1611{
   1612	struct usb_hcd		*hcd;
   1613	struct usb_device	*udev = urb->dev;
   1614	int			retval = -EIDRM;
   1615	unsigned long		flags;
   1616
   1617	/* Prevent the device and bus from going away while
   1618	 * the unlink is carried out.  If they are already gone
   1619	 * then urb->use_count must be 0, since disconnected
   1620	 * devices can't have any active URBs.
   1621	 */
   1622	spin_lock_irqsave(&hcd_urb_unlink_lock, flags);
   1623	if (atomic_read(&urb->use_count) > 0) {
   1624		retval = 0;
   1625		usb_get_dev(udev);
   1626	}
   1627	spin_unlock_irqrestore(&hcd_urb_unlink_lock, flags);
   1628	if (retval == 0) {
   1629		hcd = bus_to_hcd(urb->dev->bus);
   1630		retval = unlink1(hcd, urb, status);
   1631		if (retval == 0)
   1632			retval = -EINPROGRESS;
   1633		else if (retval != -EIDRM && retval != -EBUSY)
   1634			dev_dbg(&udev->dev, "hcd_unlink_urb %pK fail %d\n",
   1635					urb, retval);
   1636		usb_put_dev(udev);
   1637	}
   1638	return retval;
   1639}
   1640
   1641/*-------------------------------------------------------------------------*/
   1642
   1643static void __usb_hcd_giveback_urb(struct urb *urb)
   1644{
   1645	struct usb_hcd *hcd = bus_to_hcd(urb->dev->bus);
   1646	struct usb_anchor *anchor = urb->anchor;
   1647	int status = urb->unlinked;
   1648
   1649	urb->hcpriv = NULL;
   1650	if (unlikely((urb->transfer_flags & URB_SHORT_NOT_OK) &&
   1651	    urb->actual_length < urb->transfer_buffer_length &&
   1652	    !status))
   1653		status = -EREMOTEIO;
   1654
   1655	unmap_urb_for_dma(hcd, urb);
   1656	usbmon_urb_complete(&hcd->self, urb, status);
   1657	usb_anchor_suspend_wakeups(anchor);
   1658	usb_unanchor_urb(urb);
   1659	if (likely(status == 0))
   1660		usb_led_activity(USB_LED_EVENT_HOST);
   1661
   1662	/* pass ownership to the completion handler */
   1663	urb->status = status;
   1664	/*
   1665	 * This function can be called in task context inside another remote
   1666	 * coverage collection section, but kcov doesn't support that kind of
   1667	 * recursion yet. Only collect coverage in softirq context for now.
   1668	 */
   1669	kcov_remote_start_usb_softirq((u64)urb->dev->bus->busnum);
   1670	urb->complete(urb);
   1671	kcov_remote_stop_softirq();
   1672
   1673	usb_anchor_resume_wakeups(anchor);
   1674	atomic_dec(&urb->use_count);
   1675	/*
   1676	 * Order the write of urb->use_count above before the read
   1677	 * of urb->reject below.  Pairs with the memory barriers in
   1678	 * usb_kill_urb() and usb_poison_urb().
   1679	 */
   1680	smp_mb__after_atomic();
   1681
   1682	if (unlikely(atomic_read(&urb->reject)))
   1683		wake_up(&usb_kill_urb_queue);
   1684	usb_put_urb(urb);
   1685}
   1686
   1687static void usb_giveback_urb_bh(struct tasklet_struct *t)
   1688{
   1689	struct giveback_urb_bh *bh = from_tasklet(bh, t, bh);
   1690	struct list_head local_list;
   1691
   1692	spin_lock_irq(&bh->lock);
   1693	bh->running = true;
   1694 restart:
   1695	list_replace_init(&bh->head, &local_list);
   1696	spin_unlock_irq(&bh->lock);
   1697
   1698	while (!list_empty(&local_list)) {
   1699		struct urb *urb;
   1700
   1701		urb = list_entry(local_list.next, struct urb, urb_list);
   1702		list_del_init(&urb->urb_list);
   1703		bh->completing_ep = urb->ep;
   1704		__usb_hcd_giveback_urb(urb);
   1705		bh->completing_ep = NULL;
   1706	}
   1707
   1708	/* check if there are new URBs to giveback */
   1709	spin_lock_irq(&bh->lock);
   1710	if (!list_empty(&bh->head))
   1711		goto restart;
   1712	bh->running = false;
   1713	spin_unlock_irq(&bh->lock);
   1714}
   1715
   1716/**
   1717 * usb_hcd_giveback_urb - return URB from HCD to device driver
   1718 * @hcd: host controller returning the URB
   1719 * @urb: urb being returned to the USB device driver.
   1720 * @status: completion status code for the URB.
   1721 *
   1722 * Context: atomic. The completion callback is invoked in caller's context.
   1723 * For HCDs with HCD_BH flag set, the completion callback is invoked in tasklet
   1724 * context (except for URBs submitted to the root hub which always complete in
   1725 * caller's context).
   1726 *
   1727 * This hands the URB from HCD to its USB device driver, using its
   1728 * completion function.  The HCD has freed all per-urb resources
   1729 * (and is done using urb->hcpriv).  It also released all HCD locks;
   1730 * the device driver won't cause problems if it frees, modifies,
   1731 * or resubmits this URB.
   1732 *
   1733 * If @urb was unlinked, the value of @status will be overridden by
   1734 * @urb->unlinked.  Erroneous short transfers are detected in case
   1735 * the HCD hasn't checked for them.
   1736 */
   1737void usb_hcd_giveback_urb(struct usb_hcd *hcd, struct urb *urb, int status)
   1738{
   1739	struct giveback_urb_bh *bh;
   1740	bool running, high_prio_bh;
   1741
   1742	/* pass status to tasklet via unlinked */
   1743	if (likely(!urb->unlinked))
   1744		urb->unlinked = status;
   1745
   1746	if (!hcd_giveback_urb_in_bh(hcd) && !is_root_hub(urb->dev)) {
   1747		__usb_hcd_giveback_urb(urb);
   1748		return;
   1749	}
   1750
   1751	if (usb_pipeisoc(urb->pipe) || usb_pipeint(urb->pipe)) {
   1752		bh = &hcd->high_prio_bh;
   1753		high_prio_bh = true;
   1754	} else {
   1755		bh = &hcd->low_prio_bh;
   1756		high_prio_bh = false;
   1757	}
   1758
   1759	spin_lock(&bh->lock);
   1760	list_add_tail(&urb->urb_list, &bh->head);
   1761	running = bh->running;
   1762	spin_unlock(&bh->lock);
   1763
   1764	if (running)
   1765		;
   1766	else if (high_prio_bh)
   1767		tasklet_hi_schedule(&bh->bh);
   1768	else
   1769		tasklet_schedule(&bh->bh);
   1770}
   1771EXPORT_SYMBOL_GPL(usb_hcd_giveback_urb);
   1772
   1773/*-------------------------------------------------------------------------*/
   1774
   1775/* Cancel all URBs pending on this endpoint and wait for the endpoint's
   1776 * queue to drain completely.  The caller must first insure that no more
   1777 * URBs can be submitted for this endpoint.
   1778 */
   1779void usb_hcd_flush_endpoint(struct usb_device *udev,
   1780		struct usb_host_endpoint *ep)
   1781{
   1782	struct usb_hcd		*hcd;
   1783	struct urb		*urb;
   1784
   1785	if (!ep)
   1786		return;
   1787	might_sleep();
   1788	hcd = bus_to_hcd(udev->bus);
   1789
   1790	/* No more submits can occur */
   1791	spin_lock_irq(&hcd_urb_list_lock);
   1792rescan:
   1793	list_for_each_entry_reverse(urb, &ep->urb_list, urb_list) {
   1794		int	is_in;
   1795
   1796		if (urb->unlinked)
   1797			continue;
   1798		usb_get_urb (urb);
   1799		is_in = usb_urb_dir_in(urb);
   1800		spin_unlock(&hcd_urb_list_lock);
   1801
   1802		/* kick hcd */
   1803		unlink1(hcd, urb, -ESHUTDOWN);
   1804		dev_dbg (hcd->self.controller,
   1805			"shutdown urb %pK ep%d%s-%s\n",
   1806			urb, usb_endpoint_num(&ep->desc),
   1807			is_in ? "in" : "out",
   1808			usb_ep_type_string(usb_endpoint_type(&ep->desc)));
   1809		usb_put_urb (urb);
   1810
   1811		/* list contents may have changed */
   1812		spin_lock(&hcd_urb_list_lock);
   1813		goto rescan;
   1814	}
   1815	spin_unlock_irq(&hcd_urb_list_lock);
   1816
   1817	/* Wait until the endpoint queue is completely empty */
   1818	while (!list_empty (&ep->urb_list)) {
   1819		spin_lock_irq(&hcd_urb_list_lock);
   1820
   1821		/* The list may have changed while we acquired the spinlock */
   1822		urb = NULL;
   1823		if (!list_empty (&ep->urb_list)) {
   1824			urb = list_entry (ep->urb_list.prev, struct urb,
   1825					urb_list);
   1826			usb_get_urb (urb);
   1827		}
   1828		spin_unlock_irq(&hcd_urb_list_lock);
   1829
   1830		if (urb) {
   1831			usb_kill_urb (urb);
   1832			usb_put_urb (urb);
   1833		}
   1834	}
   1835}
   1836
   1837/**
   1838 * usb_hcd_alloc_bandwidth - check whether a new bandwidth setting exceeds
   1839 *				the bus bandwidth
   1840 * @udev: target &usb_device
   1841 * @new_config: new configuration to install
   1842 * @cur_alt: the current alternate interface setting
   1843 * @new_alt: alternate interface setting that is being installed
   1844 *
   1845 * To change configurations, pass in the new configuration in new_config,
   1846 * and pass NULL for cur_alt and new_alt.
   1847 *
   1848 * To reset a device's configuration (put the device in the ADDRESSED state),
   1849 * pass in NULL for new_config, cur_alt, and new_alt.
   1850 *
   1851 * To change alternate interface settings, pass in NULL for new_config,
   1852 * pass in the current alternate interface setting in cur_alt,
   1853 * and pass in the new alternate interface setting in new_alt.
   1854 *
   1855 * Return: An error if the requested bandwidth change exceeds the
   1856 * bus bandwidth or host controller internal resources.
   1857 */
   1858int usb_hcd_alloc_bandwidth(struct usb_device *udev,
   1859		struct usb_host_config *new_config,
   1860		struct usb_host_interface *cur_alt,
   1861		struct usb_host_interface *new_alt)
   1862{
   1863	int num_intfs, i, j;
   1864	struct usb_host_interface *alt = NULL;
   1865	int ret = 0;
   1866	struct usb_hcd *hcd;
   1867	struct usb_host_endpoint *ep;
   1868
   1869	hcd = bus_to_hcd(udev->bus);
   1870	if (!hcd->driver->check_bandwidth)
   1871		return 0;
   1872
   1873	/* Configuration is being removed - set configuration 0 */
   1874	if (!new_config && !cur_alt) {
   1875		for (i = 1; i < 16; ++i) {
   1876			ep = udev->ep_out[i];
   1877			if (ep)
   1878				hcd->driver->drop_endpoint(hcd, udev, ep);
   1879			ep = udev->ep_in[i];
   1880			if (ep)
   1881				hcd->driver->drop_endpoint(hcd, udev, ep);
   1882		}
   1883		hcd->driver->check_bandwidth(hcd, udev);
   1884		return 0;
   1885	}
   1886	/* Check if the HCD says there's enough bandwidth.  Enable all endpoints
   1887	 * each interface's alt setting 0 and ask the HCD to check the bandwidth
   1888	 * of the bus.  There will always be bandwidth for endpoint 0, so it's
   1889	 * ok to exclude it.
   1890	 */
   1891	if (new_config) {
   1892		num_intfs = new_config->desc.bNumInterfaces;
   1893		/* Remove endpoints (except endpoint 0, which is always on the
   1894		 * schedule) from the old config from the schedule
   1895		 */
   1896		for (i = 1; i < 16; ++i) {
   1897			ep = udev->ep_out[i];
   1898			if (ep) {
   1899				ret = hcd->driver->drop_endpoint(hcd, udev, ep);
   1900				if (ret < 0)
   1901					goto reset;
   1902			}
   1903			ep = udev->ep_in[i];
   1904			if (ep) {
   1905				ret = hcd->driver->drop_endpoint(hcd, udev, ep);
   1906				if (ret < 0)
   1907					goto reset;
   1908			}
   1909		}
   1910		for (i = 0; i < num_intfs; ++i) {
   1911			struct usb_host_interface *first_alt;
   1912			int iface_num;
   1913
   1914			first_alt = &new_config->intf_cache[i]->altsetting[0];
   1915			iface_num = first_alt->desc.bInterfaceNumber;
   1916			/* Set up endpoints for alternate interface setting 0 */
   1917			alt = usb_find_alt_setting(new_config, iface_num, 0);
   1918			if (!alt)
   1919				/* No alt setting 0? Pick the first setting. */
   1920				alt = first_alt;
   1921
   1922			for (j = 0; j < alt->desc.bNumEndpoints; j++) {
   1923				ret = hcd->driver->add_endpoint(hcd, udev, &alt->endpoint[j]);
   1924				if (ret < 0)
   1925					goto reset;
   1926			}
   1927		}
   1928	}
   1929	if (cur_alt && new_alt) {
   1930		struct usb_interface *iface = usb_ifnum_to_if(udev,
   1931				cur_alt->desc.bInterfaceNumber);
   1932
   1933		if (!iface)
   1934			return -EINVAL;
   1935		if (iface->resetting_device) {
   1936			/*
   1937			 * The USB core just reset the device, so the xHCI host
   1938			 * and the device will think alt setting 0 is installed.
   1939			 * However, the USB core will pass in the alternate
   1940			 * setting installed before the reset as cur_alt.  Dig
   1941			 * out the alternate setting 0 structure, or the first
   1942			 * alternate setting if a broken device doesn't have alt
   1943			 * setting 0.
   1944			 */
   1945			cur_alt = usb_altnum_to_altsetting(iface, 0);
   1946			if (!cur_alt)
   1947				cur_alt = &iface->altsetting[0];
   1948		}
   1949
   1950		/* Drop all the endpoints in the current alt setting */
   1951		for (i = 0; i < cur_alt->desc.bNumEndpoints; i++) {
   1952			ret = hcd->driver->drop_endpoint(hcd, udev,
   1953					&cur_alt->endpoint[i]);
   1954			if (ret < 0)
   1955				goto reset;
   1956		}
   1957		/* Add all the endpoints in the new alt setting */
   1958		for (i = 0; i < new_alt->desc.bNumEndpoints; i++) {
   1959			ret = hcd->driver->add_endpoint(hcd, udev,
   1960					&new_alt->endpoint[i]);
   1961			if (ret < 0)
   1962				goto reset;
   1963		}
   1964	}
   1965	ret = hcd->driver->check_bandwidth(hcd, udev);
   1966reset:
   1967	if (ret < 0)
   1968		hcd->driver->reset_bandwidth(hcd, udev);
   1969	return ret;
   1970}
   1971
   1972/* Disables the endpoint: synchronizes with the hcd to make sure all
   1973 * endpoint state is gone from hardware.  usb_hcd_flush_endpoint() must
   1974 * have been called previously.  Use for set_configuration, set_interface,
   1975 * driver removal, physical disconnect.
   1976 *
   1977 * example:  a qh stored in ep->hcpriv, holding state related to endpoint
   1978 * type, maxpacket size, toggle, halt status, and scheduling.
   1979 */
   1980void usb_hcd_disable_endpoint(struct usb_device *udev,
   1981		struct usb_host_endpoint *ep)
   1982{
   1983	struct usb_hcd		*hcd;
   1984
   1985	might_sleep();
   1986	hcd = bus_to_hcd(udev->bus);
   1987	if (hcd->driver->endpoint_disable)
   1988		hcd->driver->endpoint_disable(hcd, ep);
   1989}
   1990
   1991/**
   1992 * usb_hcd_reset_endpoint - reset host endpoint state
   1993 * @udev: USB device.
   1994 * @ep:   the endpoint to reset.
   1995 *
   1996 * Resets any host endpoint state such as the toggle bit, sequence
   1997 * number and current window.
   1998 */
   1999void usb_hcd_reset_endpoint(struct usb_device *udev,
   2000			    struct usb_host_endpoint *ep)
   2001{
   2002	struct usb_hcd *hcd = bus_to_hcd(udev->bus);
   2003
   2004	if (hcd->driver->endpoint_reset)
   2005		hcd->driver->endpoint_reset(hcd, ep);
   2006	else {
   2007		int epnum = usb_endpoint_num(&ep->desc);
   2008		int is_out = usb_endpoint_dir_out(&ep->desc);
   2009		int is_control = usb_endpoint_xfer_control(&ep->desc);
   2010
   2011		usb_settoggle(udev, epnum, is_out, 0);
   2012		if (is_control)
   2013			usb_settoggle(udev, epnum, !is_out, 0);
   2014	}
   2015}
   2016
   2017/**
   2018 * usb_alloc_streams - allocate bulk endpoint stream IDs.
   2019 * @interface:		alternate setting that includes all endpoints.
   2020 * @eps:		array of endpoints that need streams.
   2021 * @num_eps:		number of endpoints in the array.
   2022 * @num_streams:	number of streams to allocate.
   2023 * @mem_flags:		flags hcd should use to allocate memory.
   2024 *
   2025 * Sets up a group of bulk endpoints to have @num_streams stream IDs available.
   2026 * Drivers may queue multiple transfers to different stream IDs, which may
   2027 * complete in a different order than they were queued.
   2028 *
   2029 * Return: On success, the number of allocated streams. On failure, a negative
   2030 * error code.
   2031 */
   2032int usb_alloc_streams(struct usb_interface *interface,
   2033		struct usb_host_endpoint **eps, unsigned int num_eps,
   2034		unsigned int num_streams, gfp_t mem_flags)
   2035{
   2036	struct usb_hcd *hcd;
   2037	struct usb_device *dev;
   2038	int i, ret;
   2039
   2040	dev = interface_to_usbdev(interface);
   2041	hcd = bus_to_hcd(dev->bus);
   2042	if (!hcd->driver->alloc_streams || !hcd->driver->free_streams)
   2043		return -EINVAL;
   2044	if (dev->speed < USB_SPEED_SUPER)
   2045		return -EINVAL;
   2046	if (dev->state < USB_STATE_CONFIGURED)
   2047		return -ENODEV;
   2048
   2049	for (i = 0; i < num_eps; i++) {
   2050		/* Streams only apply to bulk endpoints. */
   2051		if (!usb_endpoint_xfer_bulk(&eps[i]->desc))
   2052			return -EINVAL;
   2053		/* Re-alloc is not allowed */
   2054		if (eps[i]->streams)
   2055			return -EINVAL;
   2056	}
   2057
   2058	ret = hcd->driver->alloc_streams(hcd, dev, eps, num_eps,
   2059			num_streams, mem_flags);
   2060	if (ret < 0)
   2061		return ret;
   2062
   2063	for (i = 0; i < num_eps; i++)
   2064		eps[i]->streams = ret;
   2065
   2066	return ret;
   2067}
   2068EXPORT_SYMBOL_GPL(usb_alloc_streams);
   2069
   2070/**
   2071 * usb_free_streams - free bulk endpoint stream IDs.
   2072 * @interface:	alternate setting that includes all endpoints.
   2073 * @eps:	array of endpoints to remove streams from.
   2074 * @num_eps:	number of endpoints in the array.
   2075 * @mem_flags:	flags hcd should use to allocate memory.
   2076 *
   2077 * Reverts a group of bulk endpoints back to not using stream IDs.
   2078 * Can fail if we are given bad arguments, or HCD is broken.
   2079 *
   2080 * Return: 0 on success. On failure, a negative error code.
   2081 */
   2082int usb_free_streams(struct usb_interface *interface,
   2083		struct usb_host_endpoint **eps, unsigned int num_eps,
   2084		gfp_t mem_flags)
   2085{
   2086	struct usb_hcd *hcd;
   2087	struct usb_device *dev;
   2088	int i, ret;
   2089
   2090	dev = interface_to_usbdev(interface);
   2091	hcd = bus_to_hcd(dev->bus);
   2092	if (dev->speed < USB_SPEED_SUPER)
   2093		return -EINVAL;
   2094
   2095	/* Double-free is not allowed */
   2096	for (i = 0; i < num_eps; i++)
   2097		if (!eps[i] || !eps[i]->streams)
   2098			return -EINVAL;
   2099
   2100	ret = hcd->driver->free_streams(hcd, dev, eps, num_eps, mem_flags);
   2101	if (ret < 0)
   2102		return ret;
   2103
   2104	for (i = 0; i < num_eps; i++)
   2105		eps[i]->streams = 0;
   2106
   2107	return ret;
   2108}
   2109EXPORT_SYMBOL_GPL(usb_free_streams);
   2110
   2111/* Protect against drivers that try to unlink URBs after the device
   2112 * is gone, by waiting until all unlinks for @udev are finished.
   2113 * Since we don't currently track URBs by device, simply wait until
   2114 * nothing is running in the locked region of usb_hcd_unlink_urb().
   2115 */
   2116void usb_hcd_synchronize_unlinks(struct usb_device *udev)
   2117{
   2118	spin_lock_irq(&hcd_urb_unlink_lock);
   2119	spin_unlock_irq(&hcd_urb_unlink_lock);
   2120}
   2121
   2122/*-------------------------------------------------------------------------*/
   2123
   2124/* called in any context */
   2125int usb_hcd_get_frame_number (struct usb_device *udev)
   2126{
   2127	struct usb_hcd	*hcd = bus_to_hcd(udev->bus);
   2128
   2129	if (!HCD_RH_RUNNING(hcd))
   2130		return -ESHUTDOWN;
   2131	return hcd->driver->get_frame_number (hcd);
   2132}
   2133
   2134/*-------------------------------------------------------------------------*/
   2135#ifdef CONFIG_USB_HCD_TEST_MODE
   2136
   2137static void usb_ehset_completion(struct urb *urb)
   2138{
   2139	struct completion  *done = urb->context;
   2140
   2141	complete(done);
   2142}
   2143/*
   2144 * Allocate and initialize a control URB. This request will be used by the
   2145 * EHSET SINGLE_STEP_SET_FEATURE test in which the DATA and STATUS stages
   2146 * of the GetDescriptor request are sent 15 seconds after the SETUP stage.
   2147 * Return NULL if failed.
   2148 */
   2149static struct urb *request_single_step_set_feature_urb(
   2150	struct usb_device	*udev,
   2151	void			*dr,
   2152	void			*buf,
   2153	struct completion	*done)
   2154{
   2155	struct urb *urb;
   2156	struct usb_hcd *hcd = bus_to_hcd(udev->bus);
   2157	struct usb_host_endpoint *ep;
   2158
   2159	urb = usb_alloc_urb(0, GFP_KERNEL);
   2160	if (!urb)
   2161		return NULL;
   2162
   2163	urb->pipe = usb_rcvctrlpipe(udev, 0);
   2164	ep = (usb_pipein(urb->pipe) ? udev->ep_in : udev->ep_out)
   2165				[usb_pipeendpoint(urb->pipe)];
   2166	if (!ep) {
   2167		usb_free_urb(urb);
   2168		return NULL;
   2169	}
   2170
   2171	urb->ep = ep;
   2172	urb->dev = udev;
   2173	urb->setup_packet = (void *)dr;
   2174	urb->transfer_buffer = buf;
   2175	urb->transfer_buffer_length = USB_DT_DEVICE_SIZE;
   2176	urb->complete = usb_ehset_completion;
   2177	urb->status = -EINPROGRESS;
   2178	urb->actual_length = 0;
   2179	urb->transfer_flags = URB_DIR_IN;
   2180	usb_get_urb(urb);
   2181	atomic_inc(&urb->use_count);
   2182	atomic_inc(&urb->dev->urbnum);
   2183	if (map_urb_for_dma(hcd, urb, GFP_KERNEL)) {
   2184		usb_put_urb(urb);
   2185		usb_free_urb(urb);
   2186		return NULL;
   2187	}
   2188
   2189	urb->context = done;
   2190	return urb;
   2191}
   2192
   2193int ehset_single_step_set_feature(struct usb_hcd *hcd, int port)
   2194{
   2195	int retval = -ENOMEM;
   2196	struct usb_ctrlrequest *dr;
   2197	struct urb *urb;
   2198	struct usb_device *udev;
   2199	struct usb_device_descriptor *buf;
   2200	DECLARE_COMPLETION_ONSTACK(done);
   2201
   2202	/* Obtain udev of the rhub's child port */
   2203	udev = usb_hub_find_child(hcd->self.root_hub, port);
   2204	if (!udev) {
   2205		dev_err(hcd->self.controller, "No device attached to the RootHub\n");
   2206		return -ENODEV;
   2207	}
   2208	buf = kmalloc(USB_DT_DEVICE_SIZE, GFP_KERNEL);
   2209	if (!buf)
   2210		return -ENOMEM;
   2211
   2212	dr = kmalloc(sizeof(struct usb_ctrlrequest), GFP_KERNEL);
   2213	if (!dr) {
   2214		kfree(buf);
   2215		return -ENOMEM;
   2216	}
   2217
   2218	/* Fill Setup packet for GetDescriptor */
   2219	dr->bRequestType = USB_DIR_IN;
   2220	dr->bRequest = USB_REQ_GET_DESCRIPTOR;
   2221	dr->wValue = cpu_to_le16(USB_DT_DEVICE << 8);
   2222	dr->wIndex = 0;
   2223	dr->wLength = cpu_to_le16(USB_DT_DEVICE_SIZE);
   2224	urb = request_single_step_set_feature_urb(udev, dr, buf, &done);
   2225	if (!urb)
   2226		goto cleanup;
   2227
   2228	/* Submit just the SETUP stage */
   2229	retval = hcd->driver->submit_single_step_set_feature(hcd, urb, 1);
   2230	if (retval)
   2231		goto out1;
   2232	if (!wait_for_completion_timeout(&done, msecs_to_jiffies(2000))) {
   2233		usb_kill_urb(urb);
   2234		retval = -ETIMEDOUT;
   2235		dev_err(hcd->self.controller,
   2236			"%s SETUP stage timed out on ep0\n", __func__);
   2237		goto out1;
   2238	}
   2239	msleep(15 * 1000);
   2240
   2241	/* Complete remaining DATA and STATUS stages using the same URB */
   2242	urb->status = -EINPROGRESS;
   2243	usb_get_urb(urb);
   2244	atomic_inc(&urb->use_count);
   2245	atomic_inc(&urb->dev->urbnum);
   2246	retval = hcd->driver->submit_single_step_set_feature(hcd, urb, 0);
   2247	if (!retval && !wait_for_completion_timeout(&done,
   2248						msecs_to_jiffies(2000))) {
   2249		usb_kill_urb(urb);
   2250		retval = -ETIMEDOUT;
   2251		dev_err(hcd->self.controller,
   2252			"%s IN stage timed out on ep0\n", __func__);
   2253	}
   2254out1:
   2255	usb_free_urb(urb);
   2256cleanup:
   2257	kfree(dr);
   2258	kfree(buf);
   2259	return retval;
   2260}
   2261EXPORT_SYMBOL_GPL(ehset_single_step_set_feature);
   2262#endif /* CONFIG_USB_HCD_TEST_MODE */
   2263
   2264/*-------------------------------------------------------------------------*/
   2265
   2266#ifdef	CONFIG_PM
   2267
   2268int hcd_bus_suspend(struct usb_device *rhdev, pm_message_t msg)
   2269{
   2270	struct usb_hcd	*hcd = bus_to_hcd(rhdev->bus);
   2271	int		status;
   2272	int		old_state = hcd->state;
   2273
   2274	dev_dbg(&rhdev->dev, "bus %ssuspend, wakeup %d\n",
   2275			(PMSG_IS_AUTO(msg) ? "auto-" : ""),
   2276			rhdev->do_remote_wakeup);
   2277	if (HCD_DEAD(hcd)) {
   2278		dev_dbg(&rhdev->dev, "skipped %s of dead bus\n", "suspend");
   2279		return 0;
   2280	}
   2281
   2282	if (!hcd->driver->bus_suspend) {
   2283		status = -ENOENT;
   2284	} else {
   2285		clear_bit(HCD_FLAG_RH_RUNNING, &hcd->flags);
   2286		hcd->state = HC_STATE_QUIESCING;
   2287		status = hcd->driver->bus_suspend(hcd);
   2288	}
   2289	if (status == 0) {
   2290		usb_set_device_state(rhdev, USB_STATE_SUSPENDED);
   2291		hcd->state = HC_STATE_SUSPENDED;
   2292
   2293		if (!PMSG_IS_AUTO(msg))
   2294			usb_phy_roothub_suspend(hcd->self.sysdev,
   2295						hcd->phy_roothub);
   2296
   2297		/* Did we race with a root-hub wakeup event? */
   2298		if (rhdev->do_remote_wakeup) {
   2299			char	buffer[6];
   2300
   2301			status = hcd->driver->hub_status_data(hcd, buffer);
   2302			if (status != 0) {
   2303				dev_dbg(&rhdev->dev, "suspend raced with wakeup event\n");
   2304				hcd_bus_resume(rhdev, PMSG_AUTO_RESUME);
   2305				status = -EBUSY;
   2306			}
   2307		}
   2308	} else {
   2309		spin_lock_irq(&hcd_root_hub_lock);
   2310		if (!HCD_DEAD(hcd)) {
   2311			set_bit(HCD_FLAG_RH_RUNNING, &hcd->flags);
   2312			hcd->state = old_state;
   2313		}
   2314		spin_unlock_irq(&hcd_root_hub_lock);
   2315		dev_dbg(&rhdev->dev, "bus %s fail, err %d\n",
   2316				"suspend", status);
   2317	}
   2318	return status;
   2319}
   2320
   2321int hcd_bus_resume(struct usb_device *rhdev, pm_message_t msg)
   2322{
   2323	struct usb_hcd	*hcd = bus_to_hcd(rhdev->bus);
   2324	int		status;
   2325	int		old_state = hcd->state;
   2326
   2327	dev_dbg(&rhdev->dev, "usb %sresume\n",
   2328			(PMSG_IS_AUTO(msg) ? "auto-" : ""));
   2329	if (HCD_DEAD(hcd)) {
   2330		dev_dbg(&rhdev->dev, "skipped %s of dead bus\n", "resume");
   2331		return 0;
   2332	}
   2333
   2334	if (!PMSG_IS_AUTO(msg)) {
   2335		status = usb_phy_roothub_resume(hcd->self.sysdev,
   2336						hcd->phy_roothub);
   2337		if (status)
   2338			return status;
   2339	}
   2340
   2341	if (!hcd->driver->bus_resume)
   2342		return -ENOENT;
   2343	if (HCD_RH_RUNNING(hcd))
   2344		return 0;
   2345
   2346	hcd->state = HC_STATE_RESUMING;
   2347	status = hcd->driver->bus_resume(hcd);
   2348	clear_bit(HCD_FLAG_WAKEUP_PENDING, &hcd->flags);
   2349	if (status == 0)
   2350		status = usb_phy_roothub_calibrate(hcd->phy_roothub);
   2351
   2352	if (status == 0) {
   2353		struct usb_device *udev;
   2354		int port1;
   2355
   2356		spin_lock_irq(&hcd_root_hub_lock);
   2357		if (!HCD_DEAD(hcd)) {
   2358			usb_set_device_state(rhdev, rhdev->actconfig
   2359					? USB_STATE_CONFIGURED
   2360					: USB_STATE_ADDRESS);
   2361			set_bit(HCD_FLAG_RH_RUNNING, &hcd->flags);
   2362			hcd->state = HC_STATE_RUNNING;
   2363		}
   2364		spin_unlock_irq(&hcd_root_hub_lock);
   2365
   2366		/*
   2367		 * Check whether any of the enabled ports on the root hub are
   2368		 * unsuspended.  If they are then a TRSMRCY delay is needed
   2369		 * (this is what the USB-2 spec calls a "global resume").
   2370		 * Otherwise we can skip the delay.
   2371		 */
   2372		usb_hub_for_each_child(rhdev, port1, udev) {
   2373			if (udev->state != USB_STATE_NOTATTACHED &&
   2374					!udev->port_is_suspended) {
   2375				usleep_range(10000, 11000);	/* TRSMRCY */
   2376				break;
   2377			}
   2378		}
   2379	} else {
   2380		hcd->state = old_state;
   2381		usb_phy_roothub_suspend(hcd->self.sysdev, hcd->phy_roothub);
   2382		dev_dbg(&rhdev->dev, "bus %s fail, err %d\n",
   2383				"resume", status);
   2384		if (status != -ESHUTDOWN)
   2385			usb_hc_died(hcd);
   2386	}
   2387	return status;
   2388}
   2389
   2390/* Workqueue routine for root-hub remote wakeup */
   2391static void hcd_resume_work(struct work_struct *work)
   2392{
   2393	struct usb_hcd *hcd = container_of(work, struct usb_hcd, wakeup_work);
   2394	struct usb_device *udev = hcd->self.root_hub;
   2395
   2396	usb_remote_wakeup(udev);
   2397}
   2398
   2399/**
   2400 * usb_hcd_resume_root_hub - called by HCD to resume its root hub
   2401 * @hcd: host controller for this root hub
   2402 *
   2403 * The USB host controller calls this function when its root hub is
   2404 * suspended (with the remote wakeup feature enabled) and a remote
   2405 * wakeup request is received.  The routine submits a workqueue request
   2406 * to resume the root hub (that is, manage its downstream ports again).
   2407 */
   2408void usb_hcd_resume_root_hub (struct usb_hcd *hcd)
   2409{
   2410	unsigned long flags;
   2411
   2412	spin_lock_irqsave (&hcd_root_hub_lock, flags);
   2413	if (hcd->rh_registered) {
   2414		pm_wakeup_event(&hcd->self.root_hub->dev, 0);
   2415		set_bit(HCD_FLAG_WAKEUP_PENDING, &hcd->flags);
   2416		queue_work(pm_wq, &hcd->wakeup_work);
   2417	}
   2418	spin_unlock_irqrestore (&hcd_root_hub_lock, flags);
   2419}
   2420EXPORT_SYMBOL_GPL(usb_hcd_resume_root_hub);
   2421
   2422#endif	/* CONFIG_PM */
   2423
   2424/*-------------------------------------------------------------------------*/
   2425
   2426#ifdef	CONFIG_USB_OTG
   2427
   2428/**
   2429 * usb_bus_start_enum - start immediate enumeration (for OTG)
   2430 * @bus: the bus (must use hcd framework)
   2431 * @port_num: 1-based number of port; usually bus->otg_port
   2432 * Context: atomic
   2433 *
   2434 * Starts enumeration, with an immediate reset followed later by
   2435 * hub_wq identifying and possibly configuring the device.
   2436 * This is needed by OTG controller drivers, where it helps meet
   2437 * HNP protocol timing requirements for starting a port reset.
   2438 *
   2439 * Return: 0 if successful.
   2440 */
   2441int usb_bus_start_enum(struct usb_bus *bus, unsigned port_num)
   2442{
   2443	struct usb_hcd		*hcd;
   2444	int			status = -EOPNOTSUPP;
   2445
   2446	/* NOTE: since HNP can't start by grabbing the bus's address0_sem,
   2447	 * boards with root hubs hooked up to internal devices (instead of
   2448	 * just the OTG port) may need more attention to resetting...
   2449	 */
   2450	hcd = bus_to_hcd(bus);
   2451	if (port_num && hcd->driver->start_port_reset)
   2452		status = hcd->driver->start_port_reset(hcd, port_num);
   2453
   2454	/* allocate hub_wq shortly after (first) root port reset finishes;
   2455	 * it may issue others, until at least 50 msecs have passed.
   2456	 */
   2457	if (status == 0)
   2458		mod_timer(&hcd->rh_timer, jiffies + msecs_to_jiffies(10));
   2459	return status;
   2460}
   2461EXPORT_SYMBOL_GPL(usb_bus_start_enum);
   2462
   2463#endif
   2464
   2465/*-------------------------------------------------------------------------*/
   2466
   2467/**
   2468 * usb_hcd_irq - hook IRQs to HCD framework (bus glue)
   2469 * @irq: the IRQ being raised
   2470 * @__hcd: pointer to the HCD whose IRQ is being signaled
   2471 *
   2472 * If the controller isn't HALTed, calls the driver's irq handler.
   2473 * Checks whether the controller is now dead.
   2474 *
   2475 * Return: %IRQ_HANDLED if the IRQ was handled. %IRQ_NONE otherwise.
   2476 */
   2477irqreturn_t usb_hcd_irq (int irq, void *__hcd)
   2478{
   2479	struct usb_hcd		*hcd = __hcd;
   2480	irqreturn_t		rc;
   2481
   2482	if (unlikely(HCD_DEAD(hcd) || !HCD_HW_ACCESSIBLE(hcd)))
   2483		rc = IRQ_NONE;
   2484	else if (hcd->driver->irq(hcd) == IRQ_NONE)
   2485		rc = IRQ_NONE;
   2486	else
   2487		rc = IRQ_HANDLED;
   2488
   2489	return rc;
   2490}
   2491EXPORT_SYMBOL_GPL(usb_hcd_irq);
   2492
   2493/*-------------------------------------------------------------------------*/
   2494
   2495/* Workqueue routine for when the root-hub has died. */
   2496static void hcd_died_work(struct work_struct *work)
   2497{
   2498	struct usb_hcd *hcd = container_of(work, struct usb_hcd, died_work);
   2499	static char *env[] = {
   2500		"ERROR=DEAD",
   2501		NULL
   2502	};
   2503
   2504	/* Notify user space that the host controller has died */
   2505	kobject_uevent_env(&hcd->self.root_hub->dev.kobj, KOBJ_OFFLINE, env);
   2506}
   2507
   2508/**
   2509 * usb_hc_died - report abnormal shutdown of a host controller (bus glue)
   2510 * @hcd: pointer to the HCD representing the controller
   2511 *
   2512 * This is called by bus glue to report a USB host controller that died
   2513 * while operations may still have been pending.  It's called automatically
   2514 * by the PCI glue, so only glue for non-PCI busses should need to call it.
   2515 *
   2516 * Only call this function with the primary HCD.
   2517 */
   2518void usb_hc_died (struct usb_hcd *hcd)
   2519{
   2520	unsigned long flags;
   2521
   2522	dev_err (hcd->self.controller, "HC died; cleaning up\n");
   2523
   2524	spin_lock_irqsave (&hcd_root_hub_lock, flags);
   2525	clear_bit(HCD_FLAG_RH_RUNNING, &hcd->flags);
   2526	set_bit(HCD_FLAG_DEAD, &hcd->flags);
   2527	if (hcd->rh_registered) {
   2528		clear_bit(HCD_FLAG_POLL_RH, &hcd->flags);
   2529
   2530		/* make hub_wq clean up old urbs and devices */
   2531		usb_set_device_state (hcd->self.root_hub,
   2532				USB_STATE_NOTATTACHED);
   2533		usb_kick_hub_wq(hcd->self.root_hub);
   2534	}
   2535	if (usb_hcd_is_primary_hcd(hcd) && hcd->shared_hcd) {
   2536		hcd = hcd->shared_hcd;
   2537		clear_bit(HCD_FLAG_RH_RUNNING, &hcd->flags);
   2538		set_bit(HCD_FLAG_DEAD, &hcd->flags);
   2539		if (hcd->rh_registered) {
   2540			clear_bit(HCD_FLAG_POLL_RH, &hcd->flags);
   2541
   2542			/* make hub_wq clean up old urbs and devices */
   2543			usb_set_device_state(hcd->self.root_hub,
   2544					USB_STATE_NOTATTACHED);
   2545			usb_kick_hub_wq(hcd->self.root_hub);
   2546		}
   2547	}
   2548
   2549	/* Handle the case where this function gets called with a shared HCD */
   2550	if (usb_hcd_is_primary_hcd(hcd))
   2551		schedule_work(&hcd->died_work);
   2552	else
   2553		schedule_work(&hcd->primary_hcd->died_work);
   2554
   2555	spin_unlock_irqrestore (&hcd_root_hub_lock, flags);
   2556	/* Make sure that the other roothub is also deallocated. */
   2557}
   2558EXPORT_SYMBOL_GPL (usb_hc_died);
   2559
   2560/*-------------------------------------------------------------------------*/
   2561
   2562static void init_giveback_urb_bh(struct giveback_urb_bh *bh)
   2563{
   2564
   2565	spin_lock_init(&bh->lock);
   2566	INIT_LIST_HEAD(&bh->head);
   2567	tasklet_setup(&bh->bh, usb_giveback_urb_bh);
   2568}
   2569
   2570struct usb_hcd *__usb_create_hcd(const struct hc_driver *driver,
   2571		struct device *sysdev, struct device *dev, const char *bus_name,
   2572		struct usb_hcd *primary_hcd)
   2573{
   2574	struct usb_hcd *hcd;
   2575
   2576	hcd = kzalloc(sizeof(*hcd) + driver->hcd_priv_size, GFP_KERNEL);
   2577	if (!hcd)
   2578		return NULL;
   2579	if (primary_hcd == NULL) {
   2580		hcd->address0_mutex = kmalloc(sizeof(*hcd->address0_mutex),
   2581				GFP_KERNEL);
   2582		if (!hcd->address0_mutex) {
   2583			kfree(hcd);
   2584			dev_dbg(dev, "hcd address0 mutex alloc failed\n");
   2585			return NULL;
   2586		}
   2587		mutex_init(hcd->address0_mutex);
   2588		hcd->bandwidth_mutex = kmalloc(sizeof(*hcd->bandwidth_mutex),
   2589				GFP_KERNEL);
   2590		if (!hcd->bandwidth_mutex) {
   2591			kfree(hcd->address0_mutex);
   2592			kfree(hcd);
   2593			dev_dbg(dev, "hcd bandwidth mutex alloc failed\n");
   2594			return NULL;
   2595		}
   2596		mutex_init(hcd->bandwidth_mutex);
   2597		dev_set_drvdata(dev, hcd);
   2598	} else {
   2599		mutex_lock(&usb_port_peer_mutex);
   2600		hcd->address0_mutex = primary_hcd->address0_mutex;
   2601		hcd->bandwidth_mutex = primary_hcd->bandwidth_mutex;
   2602		hcd->primary_hcd = primary_hcd;
   2603		primary_hcd->primary_hcd = primary_hcd;
   2604		hcd->shared_hcd = primary_hcd;
   2605		primary_hcd->shared_hcd = hcd;
   2606		mutex_unlock(&usb_port_peer_mutex);
   2607	}
   2608
   2609	kref_init(&hcd->kref);
   2610
   2611	usb_bus_init(&hcd->self);
   2612	hcd->self.controller = dev;
   2613	hcd->self.sysdev = sysdev;
   2614	hcd->self.bus_name = bus_name;
   2615
   2616	timer_setup(&hcd->rh_timer, rh_timer_func, 0);
   2617#ifdef CONFIG_PM
   2618	INIT_WORK(&hcd->wakeup_work, hcd_resume_work);
   2619#endif
   2620
   2621	INIT_WORK(&hcd->died_work, hcd_died_work);
   2622
   2623	hcd->driver = driver;
   2624	hcd->speed = driver->flags & HCD_MASK;
   2625	hcd->product_desc = (driver->product_desc) ? driver->product_desc :
   2626			"USB Host Controller";
   2627	return hcd;
   2628}
   2629EXPORT_SYMBOL_GPL(__usb_create_hcd);
   2630
   2631/**
   2632 * usb_create_shared_hcd - create and initialize an HCD structure
   2633 * @driver: HC driver that will use this hcd
   2634 * @dev: device for this HC, stored in hcd->self.controller
   2635 * @bus_name: value to store in hcd->self.bus_name
   2636 * @primary_hcd: a pointer to the usb_hcd structure that is sharing the
   2637 *              PCI device.  Only allocate certain resources for the primary HCD
   2638 *
   2639 * Context: task context, might sleep.
   2640 *
   2641 * Allocate a struct usb_hcd, with extra space at the end for the
   2642 * HC driver's private data.  Initialize the generic members of the
   2643 * hcd structure.
   2644 *
   2645 * Return: On success, a pointer to the created and initialized HCD structure.
   2646 * On failure (e.g. if memory is unavailable), %NULL.
   2647 */
   2648struct usb_hcd *usb_create_shared_hcd(const struct hc_driver *driver,
   2649		struct device *dev, const char *bus_name,
   2650		struct usb_hcd *primary_hcd)
   2651{
   2652	return __usb_create_hcd(driver, dev, dev, bus_name, primary_hcd);
   2653}
   2654EXPORT_SYMBOL_GPL(usb_create_shared_hcd);
   2655
   2656/**
   2657 * usb_create_hcd - create and initialize an HCD structure
   2658 * @driver: HC driver that will use this hcd
   2659 * @dev: device for this HC, stored in hcd->self.controller
   2660 * @bus_name: value to store in hcd->self.bus_name
   2661 *
   2662 * Context: task context, might sleep.
   2663 *
   2664 * Allocate a struct usb_hcd, with extra space at the end for the
   2665 * HC driver's private data.  Initialize the generic members of the
   2666 * hcd structure.
   2667 *
   2668 * Return: On success, a pointer to the created and initialized HCD
   2669 * structure. On failure (e.g. if memory is unavailable), %NULL.
   2670 */
   2671struct usb_hcd *usb_create_hcd(const struct hc_driver *driver,
   2672		struct device *dev, const char *bus_name)
   2673{
   2674	return __usb_create_hcd(driver, dev, dev, bus_name, NULL);
   2675}
   2676EXPORT_SYMBOL_GPL(usb_create_hcd);
   2677
   2678/*
   2679 * Roothubs that share one PCI device must also share the bandwidth mutex.
   2680 * Don't deallocate the bandwidth_mutex until the last shared usb_hcd is
   2681 * deallocated.
   2682 *
   2683 * Make sure to deallocate the bandwidth_mutex only when the last HCD is
   2684 * freed.  When hcd_release() is called for either hcd in a peer set,
   2685 * invalidate the peer's ->shared_hcd and ->primary_hcd pointers.
   2686 */
   2687static void hcd_release(struct kref *kref)
   2688{
   2689	struct usb_hcd *hcd = container_of (kref, struct usb_hcd, kref);
   2690
   2691	mutex_lock(&usb_port_peer_mutex);
   2692	if (hcd->shared_hcd) {
   2693		struct usb_hcd *peer = hcd->shared_hcd;
   2694
   2695		peer->shared_hcd = NULL;
   2696		peer->primary_hcd = NULL;
   2697	} else {
   2698		kfree(hcd->address0_mutex);
   2699		kfree(hcd->bandwidth_mutex);
   2700	}
   2701	mutex_unlock(&usb_port_peer_mutex);
   2702	kfree(hcd);
   2703}
   2704
   2705struct usb_hcd *usb_get_hcd (struct usb_hcd *hcd)
   2706{
   2707	if (hcd)
   2708		kref_get (&hcd->kref);
   2709	return hcd;
   2710}
   2711EXPORT_SYMBOL_GPL(usb_get_hcd);
   2712
   2713void usb_put_hcd (struct usb_hcd *hcd)
   2714{
   2715	if (hcd)
   2716		kref_put (&hcd->kref, hcd_release);
   2717}
   2718EXPORT_SYMBOL_GPL(usb_put_hcd);
   2719
   2720int usb_hcd_is_primary_hcd(struct usb_hcd *hcd)
   2721{
   2722	if (!hcd->primary_hcd)
   2723		return 1;
   2724	return hcd == hcd->primary_hcd;
   2725}
   2726EXPORT_SYMBOL_GPL(usb_hcd_is_primary_hcd);
   2727
   2728int usb_hcd_find_raw_port_number(struct usb_hcd *hcd, int port1)
   2729{
   2730	if (!hcd->driver->find_raw_port_number)
   2731		return port1;
   2732
   2733	return hcd->driver->find_raw_port_number(hcd, port1);
   2734}
   2735
   2736static int usb_hcd_request_irqs(struct usb_hcd *hcd,
   2737		unsigned int irqnum, unsigned long irqflags)
   2738{
   2739	int retval;
   2740
   2741	if (hcd->driver->irq) {
   2742
   2743		snprintf(hcd->irq_descr, sizeof(hcd->irq_descr), "%s:usb%d",
   2744				hcd->driver->description, hcd->self.busnum);
   2745		retval = request_irq(irqnum, &usb_hcd_irq, irqflags,
   2746				hcd->irq_descr, hcd);
   2747		if (retval != 0) {
   2748			dev_err(hcd->self.controller,
   2749					"request interrupt %d failed\n",
   2750					irqnum);
   2751			return retval;
   2752		}
   2753		hcd->irq = irqnum;
   2754		dev_info(hcd->self.controller, "irq %d, %s 0x%08llx\n", irqnum,
   2755				(hcd->driver->flags & HCD_MEMORY) ?
   2756					"io mem" : "io port",
   2757				(unsigned long long)hcd->rsrc_start);
   2758	} else {
   2759		hcd->irq = 0;
   2760		if (hcd->rsrc_start)
   2761			dev_info(hcd->self.controller, "%s 0x%08llx\n",
   2762					(hcd->driver->flags & HCD_MEMORY) ?
   2763						"io mem" : "io port",
   2764					(unsigned long long)hcd->rsrc_start);
   2765	}
   2766	return 0;
   2767}
   2768
   2769/*
   2770 * Before we free this root hub, flush in-flight peering attempts
   2771 * and disable peer lookups
   2772 */
   2773static void usb_put_invalidate_rhdev(struct usb_hcd *hcd)
   2774{
   2775	struct usb_device *rhdev;
   2776
   2777	mutex_lock(&usb_port_peer_mutex);
   2778	rhdev = hcd->self.root_hub;
   2779	hcd->self.root_hub = NULL;
   2780	mutex_unlock(&usb_port_peer_mutex);
   2781	usb_put_dev(rhdev);
   2782}
   2783
   2784/**
   2785 * usb_stop_hcd - Halt the HCD
   2786 * @hcd: the usb_hcd that has to be halted
   2787 *
   2788 * Stop the root-hub polling timer and invoke the HCD's ->stop callback.
   2789 */
   2790static void usb_stop_hcd(struct usb_hcd *hcd)
   2791{
   2792	hcd->rh_pollable = 0;
   2793	clear_bit(HCD_FLAG_POLL_RH, &hcd->flags);
   2794	del_timer_sync(&hcd->rh_timer);
   2795
   2796	hcd->driver->stop(hcd);
   2797	hcd->state = HC_STATE_HALT;
   2798
   2799	/* In case the HCD restarted the timer, stop it again. */
   2800	clear_bit(HCD_FLAG_POLL_RH, &hcd->flags);
   2801	del_timer_sync(&hcd->rh_timer);
   2802}
   2803
   2804/**
   2805 * usb_add_hcd - finish generic HCD structure initialization and register
   2806 * @hcd: the usb_hcd structure to initialize
   2807 * @irqnum: Interrupt line to allocate
   2808 * @irqflags: Interrupt type flags
   2809 *
   2810 * Finish the remaining parts of generic HCD initialization: allocate the
   2811 * buffers of consistent memory, register the bus, request the IRQ line,
   2812 * and call the driver's reset() and start() routines.
   2813 */
   2814int usb_add_hcd(struct usb_hcd *hcd,
   2815		unsigned int irqnum, unsigned long irqflags)
   2816{
   2817	int retval;
   2818	struct usb_device *rhdev;
   2819	struct usb_hcd *shared_hcd;
   2820
   2821	if (!hcd->skip_phy_initialization && usb_hcd_is_primary_hcd(hcd)) {
   2822		hcd->phy_roothub = usb_phy_roothub_alloc(hcd->self.sysdev);
   2823		if (IS_ERR(hcd->phy_roothub))
   2824			return PTR_ERR(hcd->phy_roothub);
   2825
   2826		retval = usb_phy_roothub_init(hcd->phy_roothub);
   2827		if (retval)
   2828			return retval;
   2829
   2830		retval = usb_phy_roothub_set_mode(hcd->phy_roothub,
   2831						  PHY_MODE_USB_HOST_SS);
   2832		if (retval)
   2833			retval = usb_phy_roothub_set_mode(hcd->phy_roothub,
   2834							  PHY_MODE_USB_HOST);
   2835		if (retval)
   2836			goto err_usb_phy_roothub_power_on;
   2837
   2838		retval = usb_phy_roothub_power_on(hcd->phy_roothub);
   2839		if (retval)
   2840			goto err_usb_phy_roothub_power_on;
   2841	}
   2842
   2843	dev_info(hcd->self.controller, "%s\n", hcd->product_desc);
   2844
   2845	switch (authorized_default) {
   2846	case USB_AUTHORIZE_NONE:
   2847		hcd->dev_policy = USB_DEVICE_AUTHORIZE_NONE;
   2848		break;
   2849
   2850	case USB_AUTHORIZE_ALL:
   2851		hcd->dev_policy = USB_DEVICE_AUTHORIZE_ALL;
   2852		break;
   2853
   2854	case USB_AUTHORIZE_INTERNAL:
   2855		hcd->dev_policy = USB_DEVICE_AUTHORIZE_INTERNAL;
   2856		break;
   2857
   2858	case USB_AUTHORIZE_WIRED:
   2859	default:
   2860		hcd->dev_policy = hcd->wireless ?
   2861			USB_DEVICE_AUTHORIZE_NONE : USB_DEVICE_AUTHORIZE_ALL;
   2862		break;
   2863	}
   2864
   2865	set_bit(HCD_FLAG_HW_ACCESSIBLE, &hcd->flags);
   2866
   2867	/* per default all interfaces are authorized */
   2868	set_bit(HCD_FLAG_INTF_AUTHORIZED, &hcd->flags);
   2869
   2870	/* HC is in reset state, but accessible.  Now do the one-time init,
   2871	 * bottom up so that hcds can customize the root hubs before hub_wq
   2872	 * starts talking to them.  (Note, bus id is assigned early too.)
   2873	 */
   2874	retval = hcd_buffer_create(hcd);
   2875	if (retval != 0) {
   2876		dev_dbg(hcd->self.sysdev, "pool alloc failed\n");
   2877		goto err_create_buf;
   2878	}
   2879
   2880	retval = usb_register_bus(&hcd->self);
   2881	if (retval < 0)
   2882		goto err_register_bus;
   2883
   2884	rhdev = usb_alloc_dev(NULL, &hcd->self, 0);
   2885	if (rhdev == NULL) {
   2886		dev_err(hcd->self.sysdev, "unable to allocate root hub\n");
   2887		retval = -ENOMEM;
   2888		goto err_allocate_root_hub;
   2889	}
   2890	mutex_lock(&usb_port_peer_mutex);
   2891	hcd->self.root_hub = rhdev;
   2892	mutex_unlock(&usb_port_peer_mutex);
   2893
   2894	rhdev->rx_lanes = 1;
   2895	rhdev->tx_lanes = 1;
   2896	rhdev->ssp_rate = USB_SSP_GEN_UNKNOWN;
   2897
   2898	switch (hcd->speed) {
   2899	case HCD_USB11:
   2900		rhdev->speed = USB_SPEED_FULL;
   2901		break;
   2902	case HCD_USB2:
   2903		rhdev->speed = USB_SPEED_HIGH;
   2904		break;
   2905	case HCD_USB25:
   2906		rhdev->speed = USB_SPEED_WIRELESS;
   2907		break;
   2908	case HCD_USB3:
   2909		rhdev->speed = USB_SPEED_SUPER;
   2910		break;
   2911	case HCD_USB32:
   2912		rhdev->rx_lanes = 2;
   2913		rhdev->tx_lanes = 2;
   2914		rhdev->ssp_rate = USB_SSP_GEN_2x2;
   2915		rhdev->speed = USB_SPEED_SUPER_PLUS;
   2916		break;
   2917	case HCD_USB31:
   2918		rhdev->ssp_rate = USB_SSP_GEN_2x1;
   2919		rhdev->speed = USB_SPEED_SUPER_PLUS;
   2920		break;
   2921	default:
   2922		retval = -EINVAL;
   2923		goto err_set_rh_speed;
   2924	}
   2925
   2926	/* wakeup flag init defaults to "everything works" for root hubs,
   2927	 * but drivers can override it in reset() if needed, along with
   2928	 * recording the overall controller's system wakeup capability.
   2929	 */
   2930	device_set_wakeup_capable(&rhdev->dev, 1);
   2931
   2932	/* HCD_FLAG_RH_RUNNING doesn't matter until the root hub is
   2933	 * registered.  But since the controller can die at any time,
   2934	 * let's initialize the flag before touching the hardware.
   2935	 */
   2936	set_bit(HCD_FLAG_RH_RUNNING, &hcd->flags);
   2937
   2938	/* "reset" is misnamed; its role is now one-time init. the controller
   2939	 * should already have been reset (and boot firmware kicked off etc).
   2940	 */
   2941	if (hcd->driver->reset) {
   2942		retval = hcd->driver->reset(hcd);
   2943		if (retval < 0) {
   2944			dev_err(hcd->self.controller, "can't setup: %d\n",
   2945					retval);
   2946			goto err_hcd_driver_setup;
   2947		}
   2948	}
   2949	hcd->rh_pollable = 1;
   2950
   2951	retval = usb_phy_roothub_calibrate(hcd->phy_roothub);
   2952	if (retval)
   2953		goto err_hcd_driver_setup;
   2954
   2955	/* NOTE: root hub and controller capabilities may not be the same */
   2956	if (device_can_wakeup(hcd->self.controller)
   2957			&& device_can_wakeup(&hcd->self.root_hub->dev))
   2958		dev_dbg(hcd->self.controller, "supports USB remote wakeup\n");
   2959
   2960	/* initialize tasklets */
   2961	init_giveback_urb_bh(&hcd->high_prio_bh);
   2962	init_giveback_urb_bh(&hcd->low_prio_bh);
   2963
   2964	/* enable irqs just before we start the controller,
   2965	 * if the BIOS provides legacy PCI irqs.
   2966	 */
   2967	if (usb_hcd_is_primary_hcd(hcd) && irqnum) {
   2968		retval = usb_hcd_request_irqs(hcd, irqnum, irqflags);
   2969		if (retval)
   2970			goto err_request_irq;
   2971	}
   2972
   2973	hcd->state = HC_STATE_RUNNING;
   2974	retval = hcd->driver->start(hcd);
   2975	if (retval < 0) {
   2976		dev_err(hcd->self.controller, "startup error %d\n", retval);
   2977		goto err_hcd_driver_start;
   2978	}
   2979
   2980	/* starting here, usbcore will pay attention to the shared HCD roothub */
   2981	shared_hcd = hcd->shared_hcd;
   2982	if (!usb_hcd_is_primary_hcd(hcd) && shared_hcd && HCD_DEFER_RH_REGISTER(shared_hcd)) {
   2983		retval = register_root_hub(shared_hcd);
   2984		if (retval != 0)
   2985			goto err_register_root_hub;
   2986
   2987		if (shared_hcd->uses_new_polling && HCD_POLL_RH(shared_hcd))
   2988			usb_hcd_poll_rh_status(shared_hcd);
   2989	}
   2990
   2991	/* starting here, usbcore will pay attention to this root hub */
   2992	if (!HCD_DEFER_RH_REGISTER(hcd)) {
   2993		retval = register_root_hub(hcd);
   2994		if (retval != 0)
   2995			goto err_register_root_hub;
   2996
   2997		if (hcd->uses_new_polling && HCD_POLL_RH(hcd))
   2998			usb_hcd_poll_rh_status(hcd);
   2999	}
   3000
   3001	return retval;
   3002
   3003err_register_root_hub:
   3004	usb_stop_hcd(hcd);
   3005err_hcd_driver_start:
   3006	if (usb_hcd_is_primary_hcd(hcd) && hcd->irq > 0)
   3007		free_irq(irqnum, hcd);
   3008err_request_irq:
   3009err_hcd_driver_setup:
   3010err_set_rh_speed:
   3011	usb_put_invalidate_rhdev(hcd);
   3012err_allocate_root_hub:
   3013	usb_deregister_bus(&hcd->self);
   3014err_register_bus:
   3015	hcd_buffer_destroy(hcd);
   3016err_create_buf:
   3017	usb_phy_roothub_power_off(hcd->phy_roothub);
   3018err_usb_phy_roothub_power_on:
   3019	usb_phy_roothub_exit(hcd->phy_roothub);
   3020
   3021	return retval;
   3022}
   3023EXPORT_SYMBOL_GPL(usb_add_hcd);
   3024
   3025/**
   3026 * usb_remove_hcd - shutdown processing for generic HCDs
   3027 * @hcd: the usb_hcd structure to remove
   3028 *
   3029 * Context: task context, might sleep.
   3030 *
   3031 * Disconnects the root hub, then reverses the effects of usb_add_hcd(),
   3032 * invoking the HCD's stop() method.
   3033 */
   3034void usb_remove_hcd(struct usb_hcd *hcd)
   3035{
   3036	struct usb_device *rhdev = hcd->self.root_hub;
   3037	bool rh_registered;
   3038
   3039	dev_info(hcd->self.controller, "remove, state %x\n", hcd->state);
   3040
   3041	usb_get_dev(rhdev);
   3042	clear_bit(HCD_FLAG_RH_RUNNING, &hcd->flags);
   3043	if (HC_IS_RUNNING (hcd->state))
   3044		hcd->state = HC_STATE_QUIESCING;
   3045
   3046	dev_dbg(hcd->self.controller, "roothub graceful disconnect\n");
   3047	spin_lock_irq (&hcd_root_hub_lock);
   3048	rh_registered = hcd->rh_registered;
   3049	hcd->rh_registered = 0;
   3050	spin_unlock_irq (&hcd_root_hub_lock);
   3051
   3052#ifdef CONFIG_PM
   3053	cancel_work_sync(&hcd->wakeup_work);
   3054#endif
   3055	cancel_work_sync(&hcd->died_work);
   3056
   3057	mutex_lock(&usb_bus_idr_lock);
   3058	if (rh_registered)
   3059		usb_disconnect(&rhdev);		/* Sets rhdev to NULL */
   3060	mutex_unlock(&usb_bus_idr_lock);
   3061
   3062	/*
   3063	 * tasklet_kill() isn't needed here because:
   3064	 * - driver's disconnect() called from usb_disconnect() should
   3065	 *   make sure its URBs are completed during the disconnect()
   3066	 *   callback
   3067	 *
   3068	 * - it is too late to run complete() here since driver may have
   3069	 *   been removed already now
   3070	 */
   3071
   3072	/* Prevent any more root-hub status calls from the timer.
   3073	 * The HCD might still restart the timer (if a port status change
   3074	 * interrupt occurs), but usb_hcd_poll_rh_status() won't invoke
   3075	 * the hub_status_data() callback.
   3076	 */
   3077	usb_stop_hcd(hcd);
   3078
   3079	if (usb_hcd_is_primary_hcd(hcd)) {
   3080		if (hcd->irq > 0)
   3081			free_irq(hcd->irq, hcd);
   3082	}
   3083
   3084	usb_deregister_bus(&hcd->self);
   3085	hcd_buffer_destroy(hcd);
   3086
   3087	usb_phy_roothub_power_off(hcd->phy_roothub);
   3088	usb_phy_roothub_exit(hcd->phy_roothub);
   3089
   3090	usb_put_invalidate_rhdev(hcd);
   3091	hcd->flags = 0;
   3092}
   3093EXPORT_SYMBOL_GPL(usb_remove_hcd);
   3094
   3095void
   3096usb_hcd_platform_shutdown(struct platform_device *dev)
   3097{
   3098	struct usb_hcd *hcd = platform_get_drvdata(dev);
   3099
   3100	/* No need for pm_runtime_put(), we're shutting down */
   3101	pm_runtime_get_sync(&dev->dev);
   3102
   3103	if (hcd->driver->shutdown)
   3104		hcd->driver->shutdown(hcd);
   3105}
   3106EXPORT_SYMBOL_GPL(usb_hcd_platform_shutdown);
   3107
   3108int usb_hcd_setup_local_mem(struct usb_hcd *hcd, phys_addr_t phys_addr,
   3109			    dma_addr_t dma, size_t size)
   3110{
   3111	int err;
   3112	void *local_mem;
   3113
   3114	hcd->localmem_pool = devm_gen_pool_create(hcd->self.sysdev, 4,
   3115						  dev_to_node(hcd->self.sysdev),
   3116						  dev_name(hcd->self.sysdev));
   3117	if (IS_ERR(hcd->localmem_pool))
   3118		return PTR_ERR(hcd->localmem_pool);
   3119
   3120	local_mem = devm_memremap(hcd->self.sysdev, phys_addr,
   3121				  size, MEMREMAP_WC);
   3122	if (IS_ERR(local_mem))
   3123		return PTR_ERR(local_mem);
   3124
   3125	/*
   3126	 * Here we pass a dma_addr_t but the arg type is a phys_addr_t.
   3127	 * It's not backed by system memory and thus there's no kernel mapping
   3128	 * for it.
   3129	 */
   3130	err = gen_pool_add_virt(hcd->localmem_pool, (unsigned long)local_mem,
   3131				dma, size, dev_to_node(hcd->self.sysdev));
   3132	if (err < 0) {
   3133		dev_err(hcd->self.sysdev, "gen_pool_add_virt failed with %d\n",
   3134			err);
   3135		return err;
   3136	}
   3137
   3138	return 0;
   3139}
   3140EXPORT_SYMBOL_GPL(usb_hcd_setup_local_mem);
   3141
   3142/*-------------------------------------------------------------------------*/
   3143
   3144#if IS_ENABLED(CONFIG_USB_MON)
   3145
   3146const struct usb_mon_operations *mon_ops;
   3147
   3148/*
   3149 * The registration is unlocked.
   3150 * We do it this way because we do not want to lock in hot paths.
   3151 *
   3152 * Notice that the code is minimally error-proof. Because usbmon needs
   3153 * symbols from usbcore, usbcore gets referenced and cannot be unloaded first.
   3154 */
   3155
   3156int usb_mon_register(const struct usb_mon_operations *ops)
   3157{
   3158
   3159	if (mon_ops)
   3160		return -EBUSY;
   3161
   3162	mon_ops = ops;
   3163	mb();
   3164	return 0;
   3165}
   3166EXPORT_SYMBOL_GPL (usb_mon_register);
   3167
   3168void usb_mon_deregister (void)
   3169{
   3170
   3171	if (mon_ops == NULL) {
   3172		printk(KERN_ERR "USB: monitor was not registered\n");
   3173		return;
   3174	}
   3175	mon_ops = NULL;
   3176	mb();
   3177}
   3178EXPORT_SYMBOL_GPL (usb_mon_deregister);
   3179
   3180#endif /* CONFIG_USB_MON || CONFIG_USB_MON_MODULE */