cachepc-linux

Fork of AMDESE/linux with modifications for CachePC side-channel attack
git clone https://git.sinitax.com/sinitax/cachepc-linux
Log | Files | Refs | README | LICENSE | sfeed.txt

uas-detect.h (4432B)

      1/* SPDX-License-Identifier: GPL-2.0 */
      2#include <linux/usb.h>
      3#include <linux/usb/hcd.h>
      4#include "usb.h"
      5
      6static int uas_is_interface(struct usb_host_interface *intf)
      7{
      8	return (intf->desc.bInterfaceClass == USB_CLASS_MASS_STORAGE &&
      9		intf->desc.bInterfaceSubClass == USB_SC_SCSI &&
     10		intf->desc.bInterfaceProtocol == USB_PR_UAS);
     11}
     12
     13static struct usb_host_interface *uas_find_uas_alt_setting(
     14		struct usb_interface *intf)
     15{
     16	int i;
     17
     18	for (i = 0; i < intf->num_altsetting; i++) {
     19		struct usb_host_interface *alt = &intf->altsetting[i];
     20
     21		if (uas_is_interface(alt))
     22			return alt;
     23	}
     24
     25	return NULL;
     26}
     27
     28static int uas_find_endpoints(struct usb_host_interface *alt,
     29			      struct usb_host_endpoint *eps[])
     30{
     31	struct usb_host_endpoint *endpoint = alt->endpoint;
     32	unsigned i, n_endpoints = alt->desc.bNumEndpoints;
     33
     34	for (i = 0; i < n_endpoints; i++) {
     35		unsigned char *extra = endpoint[i].extra;
     36		int len = endpoint[i].extralen;
     37		while (len >= 3) {
     38			if (extra[1] == USB_DT_PIPE_USAGE) {
     39				unsigned pipe_id = extra[2];
     40				if (pipe_id > 0 && pipe_id < 5)
     41					eps[pipe_id - 1] = &endpoint[i];
     42				break;
     43			}
     44			len -= extra[0];
     45			extra += extra[0];
     46		}
     47	}
     48
     49	if (!eps[0] || !eps[1] || !eps[2] || !eps[3])
     50		return -ENODEV;
     51
     52	return 0;
     53}
     54
     55static int uas_use_uas_driver(struct usb_interface *intf,
     56			      const struct usb_device_id *id,
     57			      unsigned long *flags_ret)
     58{
     59	struct usb_host_endpoint *eps[4] = { };
     60	struct usb_device *udev = interface_to_usbdev(intf);
     61	struct usb_hcd *hcd = bus_to_hcd(udev->bus);
     62	unsigned long flags = id->driver_info;
     63	struct usb_host_interface *alt;
     64	int r;
     65
     66	alt = uas_find_uas_alt_setting(intf);
     67	if (!alt)
     68		return 0;
     69
     70	r = uas_find_endpoints(alt, eps);
     71	if (r < 0)
     72		return 0;
     73
     74	/*
     75	 * ASMedia has a number of usb3 to sata bridge chips, at the time of
     76	 * this writing the following versions exist:
     77	 * ASM1051 - no uas support version
     78	 * ASM1051 - with broken (*) uas support
     79	 * ASM1053 - with working uas support, but problems with large xfers
     80	 * ASM1153 - with working uas support
     81	 *
     82	 * Devices with these chips re-use a number of device-ids over the
     83	 * entire line, so the device-id is useless to determine if we're
     84	 * dealing with an ASM1051 (which we want to avoid).
     85	 *
     86	 * The ASM1153 can be identified by config.MaxPower == 0,
     87	 * where as the ASM105x models have config.MaxPower == 36.
     88	 *
     89	 * Differentiating between the ASM1053 and ASM1051 is trickier, when
     90	 * connected over USB-3 we can look at the number of streams supported,
     91	 * ASM1051 supports 32 streams, where as early ASM1053 versions support
     92	 * 16 streams, newer ASM1053-s also support 32 streams, but have a
     93	 * different prod-id.
     94	 *
     95	 * (*) ASM1051 chips do work with UAS with some disks (with the
     96	 *     US_FL_NO_REPORT_OPCODES quirk), but are broken with other disks
     97	 */
     98	if (le16_to_cpu(udev->descriptor.idVendor) == 0x174c &&
     99			(le16_to_cpu(udev->descriptor.idProduct) == 0x5106 ||
    100			 le16_to_cpu(udev->descriptor.idProduct) == 0x55aa)) {
    101		if (udev->actconfig->desc.bMaxPower == 0) {
    102			/* ASM1153, do nothing */
    103		} else if (udev->speed < USB_SPEED_SUPER) {
    104			/* No streams info, assume ASM1051 */
    105			flags |= US_FL_IGNORE_UAS;
    106		} else if (usb_ss_max_streams(&eps[1]->ss_ep_comp) == 32) {
    107			/* Possibly an ASM1051, disable uas */
    108			flags |= US_FL_IGNORE_UAS;
    109		} else {
    110			/* ASM1053, these have issues with large transfers */
    111			flags |= US_FL_MAX_SECTORS_240;
    112		}
    113	}
    114
    115	/* All Seagate disk enclosures have broken ATA pass-through support */
    116	if (le16_to_cpu(udev->descriptor.idVendor) == 0x0bc2)
    117		flags |= US_FL_NO_ATA_1X;
    118
    119	usb_stor_adjust_quirks(udev, &flags);
    120
    121	if (flags & US_FL_IGNORE_UAS) {
    122		dev_warn(&udev->dev,
    123			"UAS is ignored for this device, using usb-storage instead\n");
    124		return 0;
    125	}
    126
    127	if (udev->bus->sg_tablesize == 0) {
    128		dev_warn(&udev->dev,
    129			"The driver for the USB controller %s does not support scatter-gather which is\n",
    130			hcd->driver->description);
    131		dev_warn(&udev->dev,
    132			"required by the UAS driver. Please try an other USB controller if you wish to use UAS.\n");
    133		return 0;
    134	}
    135
    136	if (udev->speed >= USB_SPEED_SUPER && !hcd->can_do_streams) {
    137		dev_warn(&udev->dev,
    138			"USB controller %s does not support streams, which are required by the UAS driver.\n",
    139			hcd_to_bus(hcd)->bus_name);
    140		dev_warn(&udev->dev,
    141			"Please try an other USB controller if you wish to use UAS.\n");
    142		return 0;
    143	}
    144
    145	if (flags_ret)
    146		*flags_ret = flags;
    147
    148	return 1;
    149}