cachepc-linux

Fork of AMDESE/linux with modifications for CachePC side-channel attack
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pci-epf-ntb.c (74340B)


      1// SPDX-License-Identifier: GPL-2.0
      2/*
      3 * Endpoint Function Driver to implement Non-Transparent Bridge functionality
      4 *
      5 * Copyright (C) 2020 Texas Instruments
      6 * Author: Kishon Vijay Abraham I <kishon@ti.com>
      7 */
      8
      9/*
     10 * The PCI NTB function driver configures the SoC with multiple PCIe Endpoint
     11 * (EP) controller instances (see diagram below) in such a way that
     12 * transactions from one EP controller are routed to the other EP controller.
     13 * Once PCI NTB function driver configures the SoC with multiple EP instances,
     14 * HOST1 and HOST2 can communicate with each other using SoC as a bridge.
     15 *
     16 *    +-------------+                                   +-------------+
     17 *    |             |                                   |             |
     18 *    |    HOST1    |                                   |    HOST2    |
     19 *    |             |                                   |             |
     20 *    +------^------+                                   +------^------+
     21 *           |                                                 |
     22 *           |                                                 |
     23 * +---------|-------------------------------------------------|---------+
     24 * |  +------v------+                                   +------v------+  |
     25 * |  |             |                                   |             |  |
     26 * |  |     EP      |                                   |     EP      |  |
     27 * |  | CONTROLLER1 |                                   | CONTROLLER2 |  |
     28 * |  |             <----------------------------------->             |  |
     29 * |  |             |                                   |             |  |
     30 * |  |             |                                   |             |  |
     31 * |  |             |  SoC With Multiple EP Instances   |             |  |
     32 * |  |             |  (Configured using NTB Function)  |             |  |
     33 * |  +-------------+                                   +-------------+  |
     34 * +---------------------------------------------------------------------+
     35 */
     36
     37#include <linux/delay.h>
     38#include <linux/io.h>
     39#include <linux/module.h>
     40#include <linux/slab.h>
     41
     42#include <linux/pci-epc.h>
     43#include <linux/pci-epf.h>
     44
     45static struct workqueue_struct *kpcintb_workqueue;
     46
     47#define COMMAND_CONFIGURE_DOORBELL	1
     48#define COMMAND_TEARDOWN_DOORBELL	2
     49#define COMMAND_CONFIGURE_MW		3
     50#define COMMAND_TEARDOWN_MW		4
     51#define COMMAND_LINK_UP			5
     52#define COMMAND_LINK_DOWN		6
     53
     54#define COMMAND_STATUS_OK		1
     55#define COMMAND_STATUS_ERROR		2
     56
     57#define LINK_STATUS_UP			BIT(0)
     58
     59#define SPAD_COUNT			64
     60#define DB_COUNT			4
     61#define NTB_MW_OFFSET			2
     62#define DB_COUNT_MASK			GENMASK(15, 0)
     63#define MSIX_ENABLE			BIT(16)
     64#define MAX_DB_COUNT			32
     65#define MAX_MW				4
     66
     67enum epf_ntb_bar {
     68	BAR_CONFIG,
     69	BAR_PEER_SPAD,
     70	BAR_DB_MW1,
     71	BAR_MW2,
     72	BAR_MW3,
     73	BAR_MW4,
     74};
     75
     76struct epf_ntb {
     77	u32 num_mws;
     78	u32 db_count;
     79	u32 spad_count;
     80	struct pci_epf *epf;
     81	u64 mws_size[MAX_MW];
     82	struct config_group group;
     83	struct epf_ntb_epc *epc[2];
     84};
     85
     86#define to_epf_ntb(epf_group) container_of((epf_group), struct epf_ntb, group)
     87
     88struct epf_ntb_epc {
     89	u8 func_no;
     90	u8 vfunc_no;
     91	bool linkup;
     92	bool is_msix;
     93	int msix_bar;
     94	u32 spad_size;
     95	struct pci_epc *epc;
     96	struct epf_ntb *epf_ntb;
     97	void __iomem *mw_addr[6];
     98	size_t msix_table_offset;
     99	struct epf_ntb_ctrl *reg;
    100	struct pci_epf_bar *epf_bar;
    101	enum pci_barno epf_ntb_bar[6];
    102	struct delayed_work cmd_handler;
    103	enum pci_epc_interface_type type;
    104	const struct pci_epc_features *epc_features;
    105};
    106
    107struct epf_ntb_ctrl {
    108	u32	command;
    109	u32	argument;
    110	u16	command_status;
    111	u16	link_status;
    112	u32	topology;
    113	u64	addr;
    114	u64	size;
    115	u32	num_mws;
    116	u32	mw1_offset;
    117	u32	spad_offset;
    118	u32	spad_count;
    119	u32	db_entry_size;
    120	u32	db_data[MAX_DB_COUNT];
    121	u32	db_offset[MAX_DB_COUNT];
    122} __packed;
    123
    124static struct pci_epf_header epf_ntb_header = {
    125	.vendorid	= PCI_ANY_ID,
    126	.deviceid	= PCI_ANY_ID,
    127	.baseclass_code	= PCI_BASE_CLASS_MEMORY,
    128	.interrupt_pin	= PCI_INTERRUPT_INTA,
    129};
    130
    131/**
    132 * epf_ntb_link_up() - Raise link_up interrupt to both the hosts
    133 * @ntb: NTB device that facilitates communication between HOST1 and HOST2
    134 * @link_up: true or false indicating Link is UP or Down
    135 *
    136 * Once NTB function in HOST1 and the NTB function in HOST2 invoke
    137 * ntb_link_enable(), this NTB function driver will trigger a link event to
    138 * the NTB client in both the hosts.
    139 */
    140static int epf_ntb_link_up(struct epf_ntb *ntb, bool link_up)
    141{
    142	enum pci_epc_interface_type type;
    143	enum pci_epc_irq_type irq_type;
    144	struct epf_ntb_epc *ntb_epc;
    145	struct epf_ntb_ctrl *ctrl;
    146	struct pci_epc *epc;
    147	u8 func_no, vfunc_no;
    148	bool is_msix;
    149	int ret;
    150
    151	for (type = PRIMARY_INTERFACE; type <= SECONDARY_INTERFACE; type++) {
    152		ntb_epc = ntb->epc[type];
    153		epc = ntb_epc->epc;
    154		func_no = ntb_epc->func_no;
    155		vfunc_no = ntb_epc->vfunc_no;
    156		is_msix = ntb_epc->is_msix;
    157		ctrl = ntb_epc->reg;
    158		if (link_up)
    159			ctrl->link_status |= LINK_STATUS_UP;
    160		else
    161			ctrl->link_status &= ~LINK_STATUS_UP;
    162		irq_type = is_msix ? PCI_EPC_IRQ_MSIX : PCI_EPC_IRQ_MSI;
    163		ret = pci_epc_raise_irq(epc, func_no, vfunc_no, irq_type, 1);
    164		if (ret) {
    165			dev_err(&epc->dev,
    166				"%s intf: Failed to raise Link Up IRQ\n",
    167				pci_epc_interface_string(type));
    168			return ret;
    169		}
    170	}
    171
    172	return 0;
    173}
    174
    175/**
    176 * epf_ntb_configure_mw() - Configure the Outbound Address Space for one host
    177 *   to access the memory window of other host
    178 * @ntb: NTB device that facilitates communication between HOST1 and HOST2
    179 * @type: PRIMARY interface or SECONDARY interface
    180 * @mw: Index of the memory window (either 0, 1, 2 or 3)
    181 *
    182 * +-----------------+    +---->+----------------+-----------+-----------------+
    183 * |       BAR0      |    |     |   Doorbell 1   +-----------> MSI|X ADDRESS 1 |
    184 * +-----------------+    |     +----------------+           +-----------------+
    185 * |       BAR1      |    |     |   Doorbell 2   +---------+ |                 |
    186 * +-----------------+----+     +----------------+         | |                 |
    187 * |       BAR2      |          |   Doorbell 3   +-------+ | +-----------------+
    188 * +-----------------+----+     +----------------+       | +-> MSI|X ADDRESS 2 |
    189 * |       BAR3      |    |     |   Doorbell 4   +-----+ |   +-----------------+
    190 * +-----------------+    |     |----------------+     | |   |                 |
    191 * |       BAR4      |    |     |                |     | |   +-----------------+
    192 * +-----------------+    |     |      MW1       +---+ | +-->+ MSI|X ADDRESS 3||
    193 * |       BAR5      |    |     |                |   | |     +-----------------+
    194 * +-----------------+    +---->-----------------+   | |     |                 |
    195 *   EP CONTROLLER 1            |                |   | |     +-----------------+
    196 *                              |                |   | +---->+ MSI|X ADDRESS 4 |
    197 *                              +----------------+   |       +-----------------+
    198 *                      (A)      EP CONTROLLER 2     |       |                 |
    199 *                                 (OB SPACE)        |       |                 |
    200 *                                                   +------->      MW1        |
    201 *                                                           |                 |
    202 *                                                           |                 |
    203 *                                                   (B)     +-----------------+
    204 *                                                           |                 |
    205 *                                                           |                 |
    206 *                                                           |                 |
    207 *                                                           |                 |
    208 *                                                           |                 |
    209 *                                                           +-----------------+
    210 *                                                           PCI Address Space
    211 *                                                           (Managed by HOST2)
    212 *
    213 * This function performs stage (B) in the above diagram (see MW1) i.e., map OB
    214 * address space of memory window to PCI address space.
    215 *
    216 * This operation requires 3 parameters
    217 *  1) Address in the outbound address space
    218 *  2) Address in the PCI Address space
    219 *  3) Size of the address region to be mapped
    220 *
    221 * The address in the outbound address space (for MW1, MW2, MW3 and MW4) is
    222 * stored in epf_bar corresponding to BAR_DB_MW1 for MW1 and BAR_MW2, BAR_MW3
    223 * BAR_MW4 for rest of the BARs of epf_ntb_epc that is connected to HOST1. This
    224 * is populated in epf_ntb_alloc_peer_mem() in this driver.
    225 *
    226 * The address and size of the PCI address region that has to be mapped would
    227 * be provided by HOST2 in ctrl->addr and ctrl->size of epf_ntb_epc that is
    228 * connected to HOST2.
    229 *
    230 * Please note Memory window1 (MW1) and Doorbell registers together will be
    231 * mapped to a single BAR (BAR2) above for 32-bit BARs. The exact BAR that's
    232 * used for Memory window (MW) can be obtained from epf_ntb_bar[BAR_DB_MW1],
    233 * epf_ntb_bar[BAR_MW2], epf_ntb_bar[BAR_MW2], epf_ntb_bar[BAR_MW2].
    234 */
    235static int epf_ntb_configure_mw(struct epf_ntb *ntb,
    236				enum pci_epc_interface_type type, u32 mw)
    237{
    238	struct epf_ntb_epc *peer_ntb_epc, *ntb_epc;
    239	struct pci_epf_bar *peer_epf_bar;
    240	enum pci_barno peer_barno;
    241	struct epf_ntb_ctrl *ctrl;
    242	phys_addr_t phys_addr;
    243	u8 func_no, vfunc_no;
    244	struct pci_epc *epc;
    245	u64 addr, size;
    246	int ret = 0;
    247
    248	ntb_epc = ntb->epc[type];
    249	epc = ntb_epc->epc;
    250
    251	peer_ntb_epc = ntb->epc[!type];
    252	peer_barno = peer_ntb_epc->epf_ntb_bar[mw + NTB_MW_OFFSET];
    253	peer_epf_bar = &peer_ntb_epc->epf_bar[peer_barno];
    254
    255	phys_addr = peer_epf_bar->phys_addr;
    256	ctrl = ntb_epc->reg;
    257	addr = ctrl->addr;
    258	size = ctrl->size;
    259	if (mw + NTB_MW_OFFSET == BAR_DB_MW1)
    260		phys_addr += ctrl->mw1_offset;
    261
    262	if (size > ntb->mws_size[mw]) {
    263		dev_err(&epc->dev,
    264			"%s intf: MW: %d Req Sz:%llxx > Supported Sz:%llx\n",
    265			pci_epc_interface_string(type), mw, size,
    266			ntb->mws_size[mw]);
    267		ret = -EINVAL;
    268		goto err_invalid_size;
    269	}
    270
    271	func_no = ntb_epc->func_no;
    272	vfunc_no = ntb_epc->vfunc_no;
    273
    274	ret = pci_epc_map_addr(epc, func_no, vfunc_no, phys_addr, addr, size);
    275	if (ret)
    276		dev_err(&epc->dev,
    277			"%s intf: Failed to map memory window %d address\n",
    278			pci_epc_interface_string(type), mw);
    279
    280err_invalid_size:
    281
    282	return ret;
    283}
    284
    285/**
    286 * epf_ntb_teardown_mw() - Teardown the configured OB ATU
    287 * @ntb: NTB device that facilitates communication between HOST1 and HOST2
    288 * @type: PRIMARY interface or SECONDARY interface
    289 * @mw: Index of the memory window (either 0, 1, 2 or 3)
    290 *
    291 * Teardown the configured OB ATU configured in epf_ntb_configure_mw() using
    292 * pci_epc_unmap_addr()
    293 */
    294static void epf_ntb_teardown_mw(struct epf_ntb *ntb,
    295				enum pci_epc_interface_type type, u32 mw)
    296{
    297	struct epf_ntb_epc *peer_ntb_epc, *ntb_epc;
    298	struct pci_epf_bar *peer_epf_bar;
    299	enum pci_barno peer_barno;
    300	struct epf_ntb_ctrl *ctrl;
    301	phys_addr_t phys_addr;
    302	u8 func_no, vfunc_no;
    303	struct pci_epc *epc;
    304
    305	ntb_epc = ntb->epc[type];
    306	epc = ntb_epc->epc;
    307
    308	peer_ntb_epc = ntb->epc[!type];
    309	peer_barno = peer_ntb_epc->epf_ntb_bar[mw + NTB_MW_OFFSET];
    310	peer_epf_bar = &peer_ntb_epc->epf_bar[peer_barno];
    311
    312	phys_addr = peer_epf_bar->phys_addr;
    313	ctrl = ntb_epc->reg;
    314	if (mw + NTB_MW_OFFSET == BAR_DB_MW1)
    315		phys_addr += ctrl->mw1_offset;
    316	func_no = ntb_epc->func_no;
    317	vfunc_no = ntb_epc->vfunc_no;
    318
    319	pci_epc_unmap_addr(epc, func_no, vfunc_no, phys_addr);
    320}
    321
    322/**
    323 * epf_ntb_configure_msi() - Map OB address space to MSI address
    324 * @ntb: NTB device that facilitates communication between HOST1 and HOST2
    325 * @type: PRIMARY interface or SECONDARY interface
    326 * @db_count: Number of doorbell interrupts to map
    327 *
    328 *+-----------------+    +----->+----------------+-----------+-----------------+
    329 *|       BAR0      |    |      |   Doorbell 1   +---+------->   MSI ADDRESS   |
    330 *+-----------------+    |      +----------------+   |       +-----------------+
    331 *|       BAR1      |    |      |   Doorbell 2   +---+       |                 |
    332 *+-----------------+----+      +----------------+   |       |                 |
    333 *|       BAR2      |           |   Doorbell 3   +---+       |                 |
    334 *+-----------------+----+      +----------------+   |       |                 |
    335 *|       BAR3      |    |      |   Doorbell 4   +---+       |                 |
    336 *+-----------------+    |      |----------------+           |                 |
    337 *|       BAR4      |    |      |                |           |                 |
    338 *+-----------------+    |      |      MW1       |           |                 |
    339 *|       BAR5      |    |      |                |           |                 |
    340 *+-----------------+    +----->-----------------+           |                 |
    341 *  EP CONTROLLER 1             |                |           |                 |
    342 *                              |                |           |                 |
    343 *                              +----------------+           +-----------------+
    344 *                     (A)       EP CONTROLLER 2             |                 |
    345 *                                 (OB SPACE)                |                 |
    346 *                                                           |      MW1        |
    347 *                                                           |                 |
    348 *                                                           |                 |
    349 *                                                   (B)     +-----------------+
    350 *                                                           |                 |
    351 *                                                           |                 |
    352 *                                                           |                 |
    353 *                                                           |                 |
    354 *                                                           |                 |
    355 *                                                           +-----------------+
    356 *                                                           PCI Address Space
    357 *                                                           (Managed by HOST2)
    358 *
    359 *
    360 * This function performs stage (B) in the above diagram (see Doorbell 1,
    361 * Doorbell 2, Doorbell 3, Doorbell 4) i.e map OB address space corresponding to
    362 * doorbell to MSI address in PCI address space.
    363 *
    364 * This operation requires 3 parameters
    365 *  1) Address reserved for doorbell in the outbound address space
    366 *  2) MSI-X address in the PCIe Address space
    367 *  3) Number of MSI-X interrupts that has to be configured
    368 *
    369 * The address in the outbound address space (for the Doorbell) is stored in
    370 * epf_bar corresponding to BAR_DB_MW1 of epf_ntb_epc that is connected to
    371 * HOST1. This is populated in epf_ntb_alloc_peer_mem() in this driver along
    372 * with address for MW1.
    373 *
    374 * pci_epc_map_msi_irq() takes the MSI address from MSI capability register
    375 * and maps the OB address (obtained in epf_ntb_alloc_peer_mem()) to the MSI
    376 * address.
    377 *
    378 * epf_ntb_configure_msi() also stores the MSI data to raise each interrupt
    379 * in db_data of the peer's control region. This helps the peer to raise
    380 * doorbell of the other host by writing db_data to the BAR corresponding to
    381 * BAR_DB_MW1.
    382 */
    383static int epf_ntb_configure_msi(struct epf_ntb *ntb,
    384				 enum pci_epc_interface_type type, u16 db_count)
    385{
    386	struct epf_ntb_epc *peer_ntb_epc, *ntb_epc;
    387	u32 db_entry_size, db_data, db_offset;
    388	struct pci_epf_bar *peer_epf_bar;
    389	struct epf_ntb_ctrl *peer_ctrl;
    390	enum pci_barno peer_barno;
    391	phys_addr_t phys_addr;
    392	u8 func_no, vfunc_no;
    393	struct pci_epc *epc;
    394	int ret, i;
    395
    396	ntb_epc = ntb->epc[type];
    397	epc = ntb_epc->epc;
    398
    399	peer_ntb_epc = ntb->epc[!type];
    400	peer_barno = peer_ntb_epc->epf_ntb_bar[BAR_DB_MW1];
    401	peer_epf_bar = &peer_ntb_epc->epf_bar[peer_barno];
    402	peer_ctrl = peer_ntb_epc->reg;
    403	db_entry_size = peer_ctrl->db_entry_size;
    404
    405	phys_addr = peer_epf_bar->phys_addr;
    406	func_no = ntb_epc->func_no;
    407	vfunc_no = ntb_epc->vfunc_no;
    408
    409	ret = pci_epc_map_msi_irq(epc, func_no, vfunc_no, phys_addr, db_count,
    410				  db_entry_size, &db_data, &db_offset);
    411	if (ret) {
    412		dev_err(&epc->dev, "%s intf: Failed to map MSI IRQ\n",
    413			pci_epc_interface_string(type));
    414		return ret;
    415	}
    416
    417	for (i = 0; i < db_count; i++) {
    418		peer_ctrl->db_data[i] = db_data | i;
    419		peer_ctrl->db_offset[i] = db_offset;
    420	}
    421
    422	return 0;
    423}
    424
    425/**
    426 * epf_ntb_configure_msix() - Map OB address space to MSI-X address
    427 * @ntb: NTB device that facilitates communication between HOST1 and HOST2
    428 * @type: PRIMARY interface or SECONDARY interface
    429 * @db_count: Number of doorbell interrupts to map
    430 *
    431 *+-----------------+    +----->+----------------+-----------+-----------------+
    432 *|       BAR0      |    |      |   Doorbell 1   +-----------> MSI-X ADDRESS 1 |
    433 *+-----------------+    |      +----------------+           +-----------------+
    434 *|       BAR1      |    |      |   Doorbell 2   +---------+ |                 |
    435 *+-----------------+----+      +----------------+         | |                 |
    436 *|       BAR2      |           |   Doorbell 3   +-------+ | +-----------------+
    437 *+-----------------+----+      +----------------+       | +-> MSI-X ADDRESS 2 |
    438 *|       BAR3      |    |      |   Doorbell 4   +-----+ |   +-----------------+
    439 *+-----------------+    |      |----------------+     | |   |                 |
    440 *|       BAR4      |    |      |                |     | |   +-----------------+
    441 *+-----------------+    |      |      MW1       +     | +-->+ MSI-X ADDRESS 3||
    442 *|       BAR5      |    |      |                |     |     +-----------------+
    443 *+-----------------+    +----->-----------------+     |     |                 |
    444 *  EP CONTROLLER 1             |                |     |     +-----------------+
    445 *                              |                |     +---->+ MSI-X ADDRESS 4 |
    446 *                              +----------------+           +-----------------+
    447 *                     (A)       EP CONTROLLER 2             |                 |
    448 *                                 (OB SPACE)                |                 |
    449 *                                                           |      MW1        |
    450 *                                                           |                 |
    451 *                                                           |                 |
    452 *                                                   (B)     +-----------------+
    453 *                                                           |                 |
    454 *                                                           |                 |
    455 *                                                           |                 |
    456 *                                                           |                 |
    457 *                                                           |                 |
    458 *                                                           +-----------------+
    459 *                                                           PCI Address Space
    460 *                                                           (Managed by HOST2)
    461 *
    462 * This function performs stage (B) in the above diagram (see Doorbell 1,
    463 * Doorbell 2, Doorbell 3, Doorbell 4) i.e map OB address space corresponding to
    464 * doorbell to MSI-X address in PCI address space.
    465 *
    466 * This operation requires 3 parameters
    467 *  1) Address reserved for doorbell in the outbound address space
    468 *  2) MSI-X address in the PCIe Address space
    469 *  3) Number of MSI-X interrupts that has to be configured
    470 *
    471 * The address in the outbound address space (for the Doorbell) is stored in
    472 * epf_bar corresponding to BAR_DB_MW1 of epf_ntb_epc that is connected to
    473 * HOST1. This is populated in epf_ntb_alloc_peer_mem() in this driver along
    474 * with address for MW1.
    475 *
    476 * The MSI-X address is in the MSI-X table of EP CONTROLLER 2 and
    477 * the count of doorbell is in ctrl->argument of epf_ntb_epc that is connected
    478 * to HOST2. MSI-X table is stored memory mapped to ntb_epc->msix_bar and the
    479 * offset is in ntb_epc->msix_table_offset. From this epf_ntb_configure_msix()
    480 * gets the MSI-X address and data.
    481 *
    482 * epf_ntb_configure_msix() also stores the MSI-X data to raise each interrupt
    483 * in db_data of the peer's control region. This helps the peer to raise
    484 * doorbell of the other host by writing db_data to the BAR corresponding to
    485 * BAR_DB_MW1.
    486 */
    487static int epf_ntb_configure_msix(struct epf_ntb *ntb,
    488				  enum pci_epc_interface_type type,
    489				  u16 db_count)
    490{
    491	const struct pci_epc_features *epc_features;
    492	struct epf_ntb_epc *peer_ntb_epc, *ntb_epc;
    493	struct pci_epf_bar *peer_epf_bar, *epf_bar;
    494	struct pci_epf_msix_tbl *msix_tbl;
    495	struct epf_ntb_ctrl *peer_ctrl;
    496	u32 db_entry_size, msg_data;
    497	enum pci_barno peer_barno;
    498	phys_addr_t phys_addr;
    499	u8 func_no, vfunc_no;
    500	struct pci_epc *epc;
    501	size_t align;
    502	u64 msg_addr;
    503	int ret, i;
    504
    505	ntb_epc = ntb->epc[type];
    506	epc = ntb_epc->epc;
    507
    508	epf_bar = &ntb_epc->epf_bar[ntb_epc->msix_bar];
    509	msix_tbl = epf_bar->addr + ntb_epc->msix_table_offset;
    510
    511	peer_ntb_epc = ntb->epc[!type];
    512	peer_barno = peer_ntb_epc->epf_ntb_bar[BAR_DB_MW1];
    513	peer_epf_bar = &peer_ntb_epc->epf_bar[peer_barno];
    514	phys_addr = peer_epf_bar->phys_addr;
    515	peer_ctrl = peer_ntb_epc->reg;
    516	epc_features = ntb_epc->epc_features;
    517	align = epc_features->align;
    518
    519	func_no = ntb_epc->func_no;
    520	vfunc_no = ntb_epc->vfunc_no;
    521	db_entry_size = peer_ctrl->db_entry_size;
    522
    523	for (i = 0; i < db_count; i++) {
    524		msg_addr = ALIGN_DOWN(msix_tbl[i].msg_addr, align);
    525		msg_data = msix_tbl[i].msg_data;
    526		ret = pci_epc_map_addr(epc, func_no, vfunc_no, phys_addr, msg_addr,
    527				       db_entry_size);
    528		if (ret) {
    529			dev_err(&epc->dev,
    530				"%s intf: Failed to configure MSI-X IRQ\n",
    531				pci_epc_interface_string(type));
    532			return ret;
    533		}
    534		phys_addr = phys_addr + db_entry_size;
    535		peer_ctrl->db_data[i] = msg_data;
    536		peer_ctrl->db_offset[i] = msix_tbl[i].msg_addr & (align - 1);
    537	}
    538	ntb_epc->is_msix = true;
    539
    540	return 0;
    541}
    542
    543/**
    544 * epf_ntb_configure_db() - Configure the Outbound Address Space for one host
    545 *   to ring the doorbell of other host
    546 * @ntb: NTB device that facilitates communication between HOST1 and HOST2
    547 * @type: PRIMARY interface or SECONDARY interface
    548 * @db_count: Count of the number of doorbells that has to be configured
    549 * @msix: Indicates whether MSI-X or MSI should be used
    550 *
    551 * Invokes epf_ntb_configure_msix() or epf_ntb_configure_msi() required for
    552 * one HOST to ring the doorbell of other HOST.
    553 */
    554static int epf_ntb_configure_db(struct epf_ntb *ntb,
    555				enum pci_epc_interface_type type,
    556				u16 db_count, bool msix)
    557{
    558	struct epf_ntb_epc *ntb_epc;
    559	struct pci_epc *epc;
    560	int ret;
    561
    562	if (db_count > MAX_DB_COUNT)
    563		return -EINVAL;
    564
    565	ntb_epc = ntb->epc[type];
    566	epc = ntb_epc->epc;
    567
    568	if (msix)
    569		ret = epf_ntb_configure_msix(ntb, type, db_count);
    570	else
    571		ret = epf_ntb_configure_msi(ntb, type, db_count);
    572
    573	if (ret)
    574		dev_err(&epc->dev, "%s intf: Failed to configure DB\n",
    575			pci_epc_interface_string(type));
    576
    577	return ret;
    578}
    579
    580/**
    581 * epf_ntb_teardown_db() - Unmap address in OB address space to MSI/MSI-X
    582 *   address
    583 * @ntb: NTB device that facilitates communication between HOST1 and HOST2
    584 * @type: PRIMARY interface or SECONDARY interface
    585 *
    586 * Invoke pci_epc_unmap_addr() to unmap OB address to MSI/MSI-X address.
    587 */
    588static void
    589epf_ntb_teardown_db(struct epf_ntb *ntb, enum pci_epc_interface_type type)
    590{
    591	struct epf_ntb_epc *peer_ntb_epc, *ntb_epc;
    592	struct pci_epf_bar *peer_epf_bar;
    593	enum pci_barno peer_barno;
    594	phys_addr_t phys_addr;
    595	u8 func_no, vfunc_no;
    596	struct pci_epc *epc;
    597
    598	ntb_epc = ntb->epc[type];
    599	epc = ntb_epc->epc;
    600
    601	peer_ntb_epc = ntb->epc[!type];
    602	peer_barno = peer_ntb_epc->epf_ntb_bar[BAR_DB_MW1];
    603	peer_epf_bar = &peer_ntb_epc->epf_bar[peer_barno];
    604	phys_addr = peer_epf_bar->phys_addr;
    605	func_no = ntb_epc->func_no;
    606	vfunc_no = ntb_epc->vfunc_no;
    607
    608	pci_epc_unmap_addr(epc, func_no, vfunc_no, phys_addr);
    609}
    610
    611/**
    612 * epf_ntb_cmd_handler() - Handle commands provided by the NTB Host
    613 * @work: work_struct for the two epf_ntb_epc (PRIMARY and SECONDARY)
    614 *
    615 * Workqueue function that gets invoked for the two epf_ntb_epc
    616 * periodically (once every 5ms) to see if it has received any commands
    617 * from NTB host. The host can send commands to configure doorbell or
    618 * configure memory window or to update link status.
    619 */
    620static void epf_ntb_cmd_handler(struct work_struct *work)
    621{
    622	enum pci_epc_interface_type type;
    623	struct epf_ntb_epc *ntb_epc;
    624	struct epf_ntb_ctrl *ctrl;
    625	u32 command, argument;
    626	struct epf_ntb *ntb;
    627	struct device *dev;
    628	u16 db_count;
    629	bool is_msix;
    630	int ret;
    631
    632	ntb_epc = container_of(work, struct epf_ntb_epc, cmd_handler.work);
    633	ctrl = ntb_epc->reg;
    634	command = ctrl->command;
    635	if (!command)
    636		goto reset_handler;
    637	argument = ctrl->argument;
    638
    639	ctrl->command = 0;
    640	ctrl->argument = 0;
    641
    642	ctrl = ntb_epc->reg;
    643	type = ntb_epc->type;
    644	ntb = ntb_epc->epf_ntb;
    645	dev = &ntb->epf->dev;
    646
    647	switch (command) {
    648	case COMMAND_CONFIGURE_DOORBELL:
    649		db_count = argument & DB_COUNT_MASK;
    650		is_msix = argument & MSIX_ENABLE;
    651		ret = epf_ntb_configure_db(ntb, type, db_count, is_msix);
    652		if (ret < 0)
    653			ctrl->command_status = COMMAND_STATUS_ERROR;
    654		else
    655			ctrl->command_status = COMMAND_STATUS_OK;
    656		break;
    657	case COMMAND_TEARDOWN_DOORBELL:
    658		epf_ntb_teardown_db(ntb, type);
    659		ctrl->command_status = COMMAND_STATUS_OK;
    660		break;
    661	case COMMAND_CONFIGURE_MW:
    662		ret = epf_ntb_configure_mw(ntb, type, argument);
    663		if (ret < 0)
    664			ctrl->command_status = COMMAND_STATUS_ERROR;
    665		else
    666			ctrl->command_status = COMMAND_STATUS_OK;
    667		break;
    668	case COMMAND_TEARDOWN_MW:
    669		epf_ntb_teardown_mw(ntb, type, argument);
    670		ctrl->command_status = COMMAND_STATUS_OK;
    671		break;
    672	case COMMAND_LINK_UP:
    673		ntb_epc->linkup = true;
    674		if (ntb->epc[PRIMARY_INTERFACE]->linkup &&
    675		    ntb->epc[SECONDARY_INTERFACE]->linkup) {
    676			ret = epf_ntb_link_up(ntb, true);
    677			if (ret < 0)
    678				ctrl->command_status = COMMAND_STATUS_ERROR;
    679			else
    680				ctrl->command_status = COMMAND_STATUS_OK;
    681			goto reset_handler;
    682		}
    683		ctrl->command_status = COMMAND_STATUS_OK;
    684		break;
    685	case COMMAND_LINK_DOWN:
    686		ntb_epc->linkup = false;
    687		ret = epf_ntb_link_up(ntb, false);
    688		if (ret < 0)
    689			ctrl->command_status = COMMAND_STATUS_ERROR;
    690		else
    691			ctrl->command_status = COMMAND_STATUS_OK;
    692		break;
    693	default:
    694		dev_err(dev, "%s intf UNKNOWN command: %d\n",
    695			pci_epc_interface_string(type), command);
    696		break;
    697	}
    698
    699reset_handler:
    700	queue_delayed_work(kpcintb_workqueue, &ntb_epc->cmd_handler,
    701			   msecs_to_jiffies(5));
    702}
    703
    704/**
    705 * epf_ntb_peer_spad_bar_clear() - Clear Peer Scratchpad BAR
    706 * @ntb_epc: EPC associated with one of the HOST which holds peer's outbound
    707 *	     address.
    708 *
    709 *+-----------------+------->+------------------+        +-----------------+
    710 *|       BAR0      |        |  CONFIG REGION   |        |       BAR0      |
    711 *+-----------------+----+   +------------------+<-------+-----------------+
    712 *|       BAR1      |    |   |SCRATCHPAD REGION |        |       BAR1      |
    713 *+-----------------+    +-->+------------------+<-------+-----------------+
    714 *|       BAR2      |            Local Memory            |       BAR2      |
    715 *+-----------------+                                    +-----------------+
    716 *|       BAR3      |                                    |       BAR3      |
    717 *+-----------------+                                    +-----------------+
    718 *|       BAR4      |                                    |       BAR4      |
    719 *+-----------------+                                    +-----------------+
    720 *|       BAR5      |                                    |       BAR5      |
    721 *+-----------------+                                    +-----------------+
    722 *  EP CONTROLLER 1                                        EP CONTROLLER 2
    723 *
    724 * Clear BAR1 of EP CONTROLLER 2 which contains the HOST2's peer scratchpad
    725 * region. While BAR1 is the default peer scratchpad BAR, an NTB could have
    726 * other BARs for peer scratchpad (because of 64-bit BARs or reserved BARs).
    727 * This function can get the exact BAR used for peer scratchpad from
    728 * epf_ntb_bar[BAR_PEER_SPAD].
    729 *
    730 * Since HOST2's peer scratchpad is also HOST1's self scratchpad, this function
    731 * gets the address of peer scratchpad from
    732 * peer_ntb_epc->epf_ntb_bar[BAR_CONFIG].
    733 */
    734static void epf_ntb_peer_spad_bar_clear(struct epf_ntb_epc *ntb_epc)
    735{
    736	struct pci_epf_bar *epf_bar;
    737	enum pci_barno barno;
    738	u8 func_no, vfunc_no;
    739	struct pci_epc *epc;
    740
    741	epc = ntb_epc->epc;
    742	func_no = ntb_epc->func_no;
    743	vfunc_no = ntb_epc->vfunc_no;
    744	barno = ntb_epc->epf_ntb_bar[BAR_PEER_SPAD];
    745	epf_bar = &ntb_epc->epf_bar[barno];
    746	pci_epc_clear_bar(epc, func_no, vfunc_no, epf_bar);
    747}
    748
    749/**
    750 * epf_ntb_peer_spad_bar_set() - Set peer scratchpad BAR
    751 * @ntb: NTB device that facilitates communication between HOST1 and HOST2
    752 * @type: PRIMARY interface or SECONDARY interface
    753 *
    754 *+-----------------+------->+------------------+        +-----------------+
    755 *|       BAR0      |        |  CONFIG REGION   |        |       BAR0      |
    756 *+-----------------+----+   +------------------+<-------+-----------------+
    757 *|       BAR1      |    |   |SCRATCHPAD REGION |        |       BAR1      |
    758 *+-----------------+    +-->+------------------+<-------+-----------------+
    759 *|       BAR2      |            Local Memory            |       BAR2      |
    760 *+-----------------+                                    +-----------------+
    761 *|       BAR3      |                                    |       BAR3      |
    762 *+-----------------+                                    +-----------------+
    763 *|       BAR4      |                                    |       BAR4      |
    764 *+-----------------+                                    +-----------------+
    765 *|       BAR5      |                                    |       BAR5      |
    766 *+-----------------+                                    +-----------------+
    767 *  EP CONTROLLER 1                                        EP CONTROLLER 2
    768 *
    769 * Set BAR1 of EP CONTROLLER 2 which contains the HOST2's peer scratchpad
    770 * region. While BAR1 is the default peer scratchpad BAR, an NTB could have
    771 * other BARs for peer scratchpad (because of 64-bit BARs or reserved BARs).
    772 * This function can get the exact BAR used for peer scratchpad from
    773 * epf_ntb_bar[BAR_PEER_SPAD].
    774 *
    775 * Since HOST2's peer scratchpad is also HOST1's self scratchpad, this function
    776 * gets the address of peer scratchpad from
    777 * peer_ntb_epc->epf_ntb_bar[BAR_CONFIG].
    778 */
    779static int epf_ntb_peer_spad_bar_set(struct epf_ntb *ntb,
    780				     enum pci_epc_interface_type type)
    781{
    782	struct epf_ntb_epc *peer_ntb_epc, *ntb_epc;
    783	struct pci_epf_bar *peer_epf_bar, *epf_bar;
    784	enum pci_barno peer_barno, barno;
    785	u32 peer_spad_offset;
    786	u8 func_no, vfunc_no;
    787	struct pci_epc *epc;
    788	struct device *dev;
    789	int ret;
    790
    791	dev = &ntb->epf->dev;
    792
    793	peer_ntb_epc = ntb->epc[!type];
    794	peer_barno = peer_ntb_epc->epf_ntb_bar[BAR_CONFIG];
    795	peer_epf_bar = &peer_ntb_epc->epf_bar[peer_barno];
    796
    797	ntb_epc = ntb->epc[type];
    798	barno = ntb_epc->epf_ntb_bar[BAR_PEER_SPAD];
    799	epf_bar = &ntb_epc->epf_bar[barno];
    800	func_no = ntb_epc->func_no;
    801	vfunc_no = ntb_epc->vfunc_no;
    802	epc = ntb_epc->epc;
    803
    804	peer_spad_offset = peer_ntb_epc->reg->spad_offset;
    805	epf_bar->phys_addr = peer_epf_bar->phys_addr + peer_spad_offset;
    806	epf_bar->size = peer_ntb_epc->spad_size;
    807	epf_bar->barno = barno;
    808	epf_bar->flags = PCI_BASE_ADDRESS_MEM_TYPE_32;
    809
    810	ret = pci_epc_set_bar(epc, func_no, vfunc_no, epf_bar);
    811	if (ret) {
    812		dev_err(dev, "%s intf: peer SPAD BAR set failed\n",
    813			pci_epc_interface_string(type));
    814		return ret;
    815	}
    816
    817	return 0;
    818}
    819
    820/**
    821 * epf_ntb_config_sspad_bar_clear() - Clear Config + Self scratchpad BAR
    822 * @ntb_epc: EPC associated with one of the HOST which holds peer's outbound
    823 *	     address.
    824 *
    825 * +-----------------+------->+------------------+        +-----------------+
    826 * |       BAR0      |        |  CONFIG REGION   |        |       BAR0      |
    827 * +-----------------+----+   +------------------+<-------+-----------------+
    828 * |       BAR1      |    |   |SCRATCHPAD REGION |        |       BAR1      |
    829 * +-----------------+    +-->+------------------+<-------+-----------------+
    830 * |       BAR2      |            Local Memory            |       BAR2      |
    831 * +-----------------+                                    +-----------------+
    832 * |       BAR3      |                                    |       BAR3      |
    833 * +-----------------+                                    +-----------------+
    834 * |       BAR4      |                                    |       BAR4      |
    835 * +-----------------+                                    +-----------------+
    836 * |       BAR5      |                                    |       BAR5      |
    837 * +-----------------+                                    +-----------------+
    838 *   EP CONTROLLER 1                                        EP CONTROLLER 2
    839 *
    840 * Clear BAR0 of EP CONTROLLER 1 which contains the HOST1's config and
    841 * self scratchpad region (removes inbound ATU configuration). While BAR0 is
    842 * the default self scratchpad BAR, an NTB could have other BARs for self
    843 * scratchpad (because of reserved BARs). This function can get the exact BAR
    844 * used for self scratchpad from epf_ntb_bar[BAR_CONFIG].
    845 *
    846 * Please note the self scratchpad region and config region is combined to
    847 * a single region and mapped using the same BAR. Also note HOST2's peer
    848 * scratchpad is HOST1's self scratchpad.
    849 */
    850static void epf_ntb_config_sspad_bar_clear(struct epf_ntb_epc *ntb_epc)
    851{
    852	struct pci_epf_bar *epf_bar;
    853	enum pci_barno barno;
    854	u8 func_no, vfunc_no;
    855	struct pci_epc *epc;
    856
    857	epc = ntb_epc->epc;
    858	func_no = ntb_epc->func_no;
    859	vfunc_no = ntb_epc->vfunc_no;
    860	barno = ntb_epc->epf_ntb_bar[BAR_CONFIG];
    861	epf_bar = &ntb_epc->epf_bar[barno];
    862	pci_epc_clear_bar(epc, func_no, vfunc_no, epf_bar);
    863}
    864
    865/**
    866 * epf_ntb_config_sspad_bar_set() - Set Config + Self scratchpad BAR
    867 * @ntb_epc: EPC associated with one of the HOST which holds peer's outbound
    868 *	     address.
    869 *
    870 * +-----------------+------->+------------------+        +-----------------+
    871 * |       BAR0      |        |  CONFIG REGION   |        |       BAR0      |
    872 * +-----------------+----+   +------------------+<-------+-----------------+
    873 * |       BAR1      |    |   |SCRATCHPAD REGION |        |       BAR1      |
    874 * +-----------------+    +-->+------------------+<-------+-----------------+
    875 * |       BAR2      |            Local Memory            |       BAR2      |
    876 * +-----------------+                                    +-----------------+
    877 * |       BAR3      |                                    |       BAR3      |
    878 * +-----------------+                                    +-----------------+
    879 * |       BAR4      |                                    |       BAR4      |
    880 * +-----------------+                                    +-----------------+
    881 * |       BAR5      |                                    |       BAR5      |
    882 * +-----------------+                                    +-----------------+
    883 *   EP CONTROLLER 1                                        EP CONTROLLER 2
    884 *
    885 * Map BAR0 of EP CONTROLLER 1 which contains the HOST1's config and
    886 * self scratchpad region. While BAR0 is the default self scratchpad BAR, an
    887 * NTB could have other BARs for self scratchpad (because of reserved BARs).
    888 * This function can get the exact BAR used for self scratchpad from
    889 * epf_ntb_bar[BAR_CONFIG].
    890 *
    891 * Please note the self scratchpad region and config region is combined to
    892 * a single region and mapped using the same BAR. Also note HOST2's peer
    893 * scratchpad is HOST1's self scratchpad.
    894 */
    895static int epf_ntb_config_sspad_bar_set(struct epf_ntb_epc *ntb_epc)
    896{
    897	struct pci_epf_bar *epf_bar;
    898	enum pci_barno barno;
    899	u8 func_no, vfunc_no;
    900	struct epf_ntb *ntb;
    901	struct pci_epc *epc;
    902	struct device *dev;
    903	int ret;
    904
    905	ntb = ntb_epc->epf_ntb;
    906	dev = &ntb->epf->dev;
    907
    908	epc = ntb_epc->epc;
    909	func_no = ntb_epc->func_no;
    910	vfunc_no = ntb_epc->vfunc_no;
    911	barno = ntb_epc->epf_ntb_bar[BAR_CONFIG];
    912	epf_bar = &ntb_epc->epf_bar[barno];
    913
    914	ret = pci_epc_set_bar(epc, func_no, vfunc_no, epf_bar);
    915	if (ret) {
    916		dev_err(dev, "%s inft: Config/Status/SPAD BAR set failed\n",
    917			pci_epc_interface_string(ntb_epc->type));
    918		return ret;
    919	}
    920
    921	return 0;
    922}
    923
    924/**
    925 * epf_ntb_config_spad_bar_free() - Free the physical memory associated with
    926 *   config + scratchpad region
    927 * @ntb: NTB device that facilitates communication between HOST1 and HOST2
    928 *
    929 * +-----------------+------->+------------------+        +-----------------+
    930 * |       BAR0      |        |  CONFIG REGION   |        |       BAR0      |
    931 * +-----------------+----+   +------------------+<-------+-----------------+
    932 * |       BAR1      |    |   |SCRATCHPAD REGION |        |       BAR1      |
    933 * +-----------------+    +-->+------------------+<-------+-----------------+
    934 * |       BAR2      |            Local Memory            |       BAR2      |
    935 * +-----------------+                                    +-----------------+
    936 * |       BAR3      |                                    |       BAR3      |
    937 * +-----------------+                                    +-----------------+
    938 * |       BAR4      |                                    |       BAR4      |
    939 * +-----------------+                                    +-----------------+
    940 * |       BAR5      |                                    |       BAR5      |
    941 * +-----------------+                                    +-----------------+
    942 *   EP CONTROLLER 1                                        EP CONTROLLER 2
    943 *
    944 * Free the Local Memory mentioned in the above diagram. After invoking this
    945 * function, any of config + self scratchpad region of HOST1 or peer scratchpad
    946 * region of HOST2 should not be accessed.
    947 */
    948static void epf_ntb_config_spad_bar_free(struct epf_ntb *ntb)
    949{
    950	enum pci_epc_interface_type type;
    951	struct epf_ntb_epc *ntb_epc;
    952	enum pci_barno barno;
    953	struct pci_epf *epf;
    954
    955	epf = ntb->epf;
    956	for (type = PRIMARY_INTERFACE; type <= SECONDARY_INTERFACE; type++) {
    957		ntb_epc = ntb->epc[type];
    958		barno = ntb_epc->epf_ntb_bar[BAR_CONFIG];
    959		if (ntb_epc->reg)
    960			pci_epf_free_space(epf, ntb_epc->reg, barno, type);
    961	}
    962}
    963
    964/**
    965 * epf_ntb_config_spad_bar_alloc() - Allocate memory for config + scratchpad
    966 *   region
    967 * @ntb: NTB device that facilitates communication between HOST1 and HOST2
    968 * @type: PRIMARY interface or SECONDARY interface
    969 *
    970 * +-----------------+------->+------------------+        +-----------------+
    971 * |       BAR0      |        |  CONFIG REGION   |        |       BAR0      |
    972 * +-----------------+----+   +------------------+<-------+-----------------+
    973 * |       BAR1      |    |   |SCRATCHPAD REGION |        |       BAR1      |
    974 * +-----------------+    +-->+------------------+<-------+-----------------+
    975 * |       BAR2      |            Local Memory            |       BAR2      |
    976 * +-----------------+                                    +-----------------+
    977 * |       BAR3      |                                    |       BAR3      |
    978 * +-----------------+                                    +-----------------+
    979 * |       BAR4      |                                    |       BAR4      |
    980 * +-----------------+                                    +-----------------+
    981 * |       BAR5      |                                    |       BAR5      |
    982 * +-----------------+                                    +-----------------+
    983 *   EP CONTROLLER 1                                        EP CONTROLLER 2
    984 *
    985 * Allocate the Local Memory mentioned in the above diagram. The size of
    986 * CONFIG REGION is sizeof(struct epf_ntb_ctrl) and size of SCRATCHPAD REGION
    987 * is obtained from "spad-count" configfs entry.
    988 *
    989 * The size of both config region and scratchpad region has to be aligned,
    990 * since the scratchpad region will also be mapped as PEER SCRATCHPAD of
    991 * other host using a separate BAR.
    992 */
    993static int epf_ntb_config_spad_bar_alloc(struct epf_ntb *ntb,
    994					 enum pci_epc_interface_type type)
    995{
    996	const struct pci_epc_features *peer_epc_features, *epc_features;
    997	struct epf_ntb_epc *peer_ntb_epc, *ntb_epc;
    998	size_t msix_table_size, pba_size, align;
    999	enum pci_barno peer_barno, barno;
   1000	struct epf_ntb_ctrl *ctrl;
   1001	u32 spad_size, ctrl_size;
   1002	u64 size, peer_size;
   1003	struct pci_epf *epf;
   1004	struct device *dev;
   1005	bool msix_capable;
   1006	u32 spad_count;
   1007	void *base;
   1008
   1009	epf = ntb->epf;
   1010	dev = &epf->dev;
   1011	ntb_epc = ntb->epc[type];
   1012
   1013	epc_features = ntb_epc->epc_features;
   1014	barno = ntb_epc->epf_ntb_bar[BAR_CONFIG];
   1015	size = epc_features->bar_fixed_size[barno];
   1016	align = epc_features->align;
   1017
   1018	peer_ntb_epc = ntb->epc[!type];
   1019	peer_epc_features = peer_ntb_epc->epc_features;
   1020	peer_barno = ntb_epc->epf_ntb_bar[BAR_PEER_SPAD];
   1021	peer_size = peer_epc_features->bar_fixed_size[peer_barno];
   1022
   1023	/* Check if epc_features is populated incorrectly */
   1024	if ((!IS_ALIGNED(size, align)))
   1025		return -EINVAL;
   1026
   1027	spad_count = ntb->spad_count;
   1028
   1029	ctrl_size = sizeof(struct epf_ntb_ctrl);
   1030	spad_size = spad_count * 4;
   1031
   1032	msix_capable = epc_features->msix_capable;
   1033	if (msix_capable) {
   1034		msix_table_size = PCI_MSIX_ENTRY_SIZE * ntb->db_count;
   1035		ctrl_size = ALIGN(ctrl_size, 8);
   1036		ntb_epc->msix_table_offset = ctrl_size;
   1037		ntb_epc->msix_bar = barno;
   1038		/* Align to QWORD or 8 Bytes */
   1039		pba_size = ALIGN(DIV_ROUND_UP(ntb->db_count, 8), 8);
   1040		ctrl_size = ctrl_size + msix_table_size + pba_size;
   1041	}
   1042
   1043	if (!align) {
   1044		ctrl_size = roundup_pow_of_two(ctrl_size);
   1045		spad_size = roundup_pow_of_two(spad_size);
   1046	} else {
   1047		ctrl_size = ALIGN(ctrl_size, align);
   1048		spad_size = ALIGN(spad_size, align);
   1049	}
   1050
   1051	if (peer_size) {
   1052		if (peer_size < spad_size)
   1053			spad_count = peer_size / 4;
   1054		spad_size = peer_size;
   1055	}
   1056
   1057	/*
   1058	 * In order to make sure SPAD offset is aligned to its size,
   1059	 * expand control region size to the size of SPAD if SPAD size
   1060	 * is greater than control region size.
   1061	 */
   1062	if (spad_size > ctrl_size)
   1063		ctrl_size = spad_size;
   1064
   1065	if (!size)
   1066		size = ctrl_size + spad_size;
   1067	else if (size < ctrl_size + spad_size)
   1068		return -EINVAL;
   1069
   1070	base = pci_epf_alloc_space(epf, size, barno, align, type);
   1071	if (!base) {
   1072		dev_err(dev, "%s intf: Config/Status/SPAD alloc region fail\n",
   1073			pci_epc_interface_string(type));
   1074		return -ENOMEM;
   1075	}
   1076
   1077	ntb_epc->reg = base;
   1078
   1079	ctrl = ntb_epc->reg;
   1080	ctrl->spad_offset = ctrl_size;
   1081	ctrl->spad_count = spad_count;
   1082	ctrl->num_mws = ntb->num_mws;
   1083	ctrl->db_entry_size = align ? align : 4;
   1084	ntb_epc->spad_size = spad_size;
   1085
   1086	return 0;
   1087}
   1088
   1089/**
   1090 * epf_ntb_config_spad_bar_alloc_interface() - Allocate memory for config +
   1091 *   scratchpad region for each of PRIMARY and SECONDARY interface
   1092 * @ntb: NTB device that facilitates communication between HOST1 and HOST2
   1093 *
   1094 * Wrapper for epf_ntb_config_spad_bar_alloc() which allocates memory for
   1095 * config + scratchpad region for a specific interface
   1096 */
   1097static int epf_ntb_config_spad_bar_alloc_interface(struct epf_ntb *ntb)
   1098{
   1099	enum pci_epc_interface_type type;
   1100	struct device *dev;
   1101	int ret;
   1102
   1103	dev = &ntb->epf->dev;
   1104
   1105	for (type = PRIMARY_INTERFACE; type <= SECONDARY_INTERFACE; type++) {
   1106		ret = epf_ntb_config_spad_bar_alloc(ntb, type);
   1107		if (ret) {
   1108			dev_err(dev, "%s intf: Config/SPAD BAR alloc failed\n",
   1109				pci_epc_interface_string(type));
   1110			return ret;
   1111		}
   1112	}
   1113
   1114	return 0;
   1115}
   1116
   1117/**
   1118 * epf_ntb_free_peer_mem() - Free memory allocated in peers outbound address
   1119 *   space
   1120 * @ntb_epc: EPC associated with one of the HOST which holds peers outbound
   1121 *   address regions
   1122 *
   1123 * +-----------------+    +---->+----------------+-----------+-----------------+
   1124 * |       BAR0      |    |     |   Doorbell 1   +-----------> MSI|X ADDRESS 1 |
   1125 * +-----------------+    |     +----------------+           +-----------------+
   1126 * |       BAR1      |    |     |   Doorbell 2   +---------+ |                 |
   1127 * +-----------------+----+     +----------------+         | |                 |
   1128 * |       BAR2      |          |   Doorbell 3   +-------+ | +-----------------+
   1129 * +-----------------+----+     +----------------+       | +-> MSI|X ADDRESS 2 |
   1130 * |       BAR3      |    |     |   Doorbell 4   +-----+ |   +-----------------+
   1131 * +-----------------+    |     |----------------+     | |   |                 |
   1132 * |       BAR4      |    |     |                |     | |   +-----------------+
   1133 * +-----------------+    |     |      MW1       +---+ | +-->+ MSI|X ADDRESS 3||
   1134 * |       BAR5      |    |     |                |   | |     +-----------------+
   1135 * +-----------------+    +---->-----------------+   | |     |                 |
   1136 *   EP CONTROLLER 1            |                |   | |     +-----------------+
   1137 *                              |                |   | +---->+ MSI|X ADDRESS 4 |
   1138 *                              +----------------+   |       +-----------------+
   1139 *                      (A)      EP CONTROLLER 2     |       |                 |
   1140 *                                 (OB SPACE)        |       |                 |
   1141 *                                                   +------->      MW1        |
   1142 *                                                           |                 |
   1143 *                                                           |                 |
   1144 *                                                   (B)     +-----------------+
   1145 *                                                           |                 |
   1146 *                                                           |                 |
   1147 *                                                           |                 |
   1148 *                                                           |                 |
   1149 *                                                           |                 |
   1150 *                                                           +-----------------+
   1151 *                                                           PCI Address Space
   1152 *                                                           (Managed by HOST2)
   1153 *
   1154 * Free memory allocated in EP CONTROLLER 2 (OB SPACE) in the above diagram.
   1155 * It'll free Doorbell 1, Doorbell 2, Doorbell 3, Doorbell 4, MW1 (and MW2, MW3,
   1156 * MW4).
   1157 */
   1158static void epf_ntb_free_peer_mem(struct epf_ntb_epc *ntb_epc)
   1159{
   1160	struct pci_epf_bar *epf_bar;
   1161	void __iomem *mw_addr;
   1162	phys_addr_t phys_addr;
   1163	enum epf_ntb_bar bar;
   1164	enum pci_barno barno;
   1165	struct pci_epc *epc;
   1166	size_t size;
   1167
   1168	epc = ntb_epc->epc;
   1169
   1170	for (bar = BAR_DB_MW1; bar < BAR_MW4; bar++) {
   1171		barno = ntb_epc->epf_ntb_bar[bar];
   1172		mw_addr = ntb_epc->mw_addr[barno];
   1173		epf_bar = &ntb_epc->epf_bar[barno];
   1174		phys_addr = epf_bar->phys_addr;
   1175		size = epf_bar->size;
   1176		if (mw_addr) {
   1177			pci_epc_mem_free_addr(epc, phys_addr, mw_addr, size);
   1178			ntb_epc->mw_addr[barno] = NULL;
   1179		}
   1180	}
   1181}
   1182
   1183/**
   1184 * epf_ntb_db_mw_bar_clear() - Clear doorbell and memory BAR
   1185 * @ntb_epc: EPC associated with one of the HOST which holds peer's outbound
   1186 *   address
   1187 *
   1188 * +-----------------+    +---->+----------------+-----------+-----------------+
   1189 * |       BAR0      |    |     |   Doorbell 1   +-----------> MSI|X ADDRESS 1 |
   1190 * +-----------------+    |     +----------------+           +-----------------+
   1191 * |       BAR1      |    |     |   Doorbell 2   +---------+ |                 |
   1192 * +-----------------+----+     +----------------+         | |                 |
   1193 * |       BAR2      |          |   Doorbell 3   +-------+ | +-----------------+
   1194 * +-----------------+----+     +----------------+       | +-> MSI|X ADDRESS 2 |
   1195 * |       BAR3      |    |     |   Doorbell 4   +-----+ |   +-----------------+
   1196 * +-----------------+    |     |----------------+     | |   |                 |
   1197 * |       BAR4      |    |     |                |     | |   +-----------------+
   1198 * +-----------------+    |     |      MW1       +---+ | +-->+ MSI|X ADDRESS 3||
   1199 * |       BAR5      |    |     |                |   | |     +-----------------+
   1200 * +-----------------+    +---->-----------------+   | |     |                 |
   1201 *   EP CONTROLLER 1            |                |   | |     +-----------------+
   1202 *                              |                |   | +---->+ MSI|X ADDRESS 4 |
   1203 *                              +----------------+   |       +-----------------+
   1204 *                      (A)      EP CONTROLLER 2     |       |                 |
   1205 *                                 (OB SPACE)        |       |                 |
   1206 *                                                   +------->      MW1        |
   1207 *                                                           |                 |
   1208 *                                                           |                 |
   1209 *                                                   (B)     +-----------------+
   1210 *                                                           |                 |
   1211 *                                                           |                 |
   1212 *                                                           |                 |
   1213 *                                                           |                 |
   1214 *                                                           |                 |
   1215 *                                                           +-----------------+
   1216 *                                                           PCI Address Space
   1217 *                                                           (Managed by HOST2)
   1218 *
   1219 * Clear doorbell and memory BARs (remove inbound ATU configuration). In the above
   1220 * diagram it clears BAR2 TO BAR5 of EP CONTROLLER 1 (Doorbell BAR, MW1 BAR, MW2
   1221 * BAR, MW3 BAR and MW4 BAR).
   1222 */
   1223static void epf_ntb_db_mw_bar_clear(struct epf_ntb_epc *ntb_epc)
   1224{
   1225	struct pci_epf_bar *epf_bar;
   1226	enum epf_ntb_bar bar;
   1227	enum pci_barno barno;
   1228	u8 func_no, vfunc_no;
   1229	struct pci_epc *epc;
   1230
   1231	epc = ntb_epc->epc;
   1232
   1233	func_no = ntb_epc->func_no;
   1234	vfunc_no = ntb_epc->vfunc_no;
   1235
   1236	for (bar = BAR_DB_MW1; bar < BAR_MW4; bar++) {
   1237		barno = ntb_epc->epf_ntb_bar[bar];
   1238		epf_bar = &ntb_epc->epf_bar[barno];
   1239		pci_epc_clear_bar(epc, func_no, vfunc_no, epf_bar);
   1240	}
   1241}
   1242
   1243/**
   1244 * epf_ntb_db_mw_bar_cleanup() - Clear doorbell/memory BAR and free memory
   1245 *   allocated in peers outbound address space
   1246 * @ntb: NTB device that facilitates communication between HOST1 and HOST2
   1247 * @type: PRIMARY interface or SECONDARY interface
   1248 *
   1249 * Wrapper for epf_ntb_db_mw_bar_clear() to clear HOST1's BAR and
   1250 * epf_ntb_free_peer_mem() which frees up HOST2 outbound memory.
   1251 */
   1252static void epf_ntb_db_mw_bar_cleanup(struct epf_ntb *ntb,
   1253				      enum pci_epc_interface_type type)
   1254{
   1255	struct epf_ntb_epc *peer_ntb_epc, *ntb_epc;
   1256
   1257	ntb_epc = ntb->epc[type];
   1258	peer_ntb_epc = ntb->epc[!type];
   1259
   1260	epf_ntb_db_mw_bar_clear(ntb_epc);
   1261	epf_ntb_free_peer_mem(peer_ntb_epc);
   1262}
   1263
   1264/**
   1265 * epf_ntb_configure_interrupt() - Configure MSI/MSI-X capability
   1266 * @ntb: NTB device that facilitates communication between HOST1 and HOST2
   1267 * @type: PRIMARY interface or SECONDARY interface
   1268 *
   1269 * Configure MSI/MSI-X capability for each interface with number of
   1270 * interrupts equal to "db_count" configfs entry.
   1271 */
   1272static int epf_ntb_configure_interrupt(struct epf_ntb *ntb,
   1273				       enum pci_epc_interface_type type)
   1274{
   1275	const struct pci_epc_features *epc_features;
   1276	bool msix_capable, msi_capable;
   1277	struct epf_ntb_epc *ntb_epc;
   1278	u8 func_no, vfunc_no;
   1279	struct pci_epc *epc;
   1280	struct device *dev;
   1281	u32 db_count;
   1282	int ret;
   1283
   1284	ntb_epc = ntb->epc[type];
   1285	dev = &ntb->epf->dev;
   1286
   1287	epc_features = ntb_epc->epc_features;
   1288	msix_capable = epc_features->msix_capable;
   1289	msi_capable = epc_features->msi_capable;
   1290
   1291	if (!(msix_capable || msi_capable)) {
   1292		dev_err(dev, "MSI or MSI-X is required for doorbell\n");
   1293		return -EINVAL;
   1294	}
   1295
   1296	func_no = ntb_epc->func_no;
   1297	vfunc_no = ntb_epc->vfunc_no;
   1298
   1299	db_count = ntb->db_count;
   1300	if (db_count > MAX_DB_COUNT) {
   1301		dev_err(dev, "DB count cannot be more than %d\n", MAX_DB_COUNT);
   1302		return -EINVAL;
   1303	}
   1304
   1305	ntb->db_count = db_count;
   1306	epc = ntb_epc->epc;
   1307
   1308	if (msi_capable) {
   1309		ret = pci_epc_set_msi(epc, func_no, vfunc_no, db_count);
   1310		if (ret) {
   1311			dev_err(dev, "%s intf: MSI configuration failed\n",
   1312				pci_epc_interface_string(type));
   1313			return ret;
   1314		}
   1315	}
   1316
   1317	if (msix_capable) {
   1318		ret = pci_epc_set_msix(epc, func_no, vfunc_no, db_count,
   1319				       ntb_epc->msix_bar,
   1320				       ntb_epc->msix_table_offset);
   1321		if (ret) {
   1322			dev_err(dev, "MSI configuration failed\n");
   1323			return ret;
   1324		}
   1325	}
   1326
   1327	return 0;
   1328}
   1329
   1330/**
   1331 * epf_ntb_alloc_peer_mem() - Allocate memory in peer's outbound address space
   1332 * @dev: The PCI device.
   1333 * @ntb_epc: EPC associated with one of the HOST whose BAR holds peer's outbound
   1334 *   address
   1335 * @bar: BAR of @ntb_epc in for which memory has to be allocated (could be
   1336 *   BAR_DB_MW1, BAR_MW2, BAR_MW3, BAR_MW4)
   1337 * @peer_ntb_epc: EPC associated with HOST whose outbound address space is
   1338 *   used by @ntb_epc
   1339 * @size: Size of the address region that has to be allocated in peers OB SPACE
   1340 *
   1341 *
   1342 * +-----------------+    +---->+----------------+-----------+-----------------+
   1343 * |       BAR0      |    |     |   Doorbell 1   +-----------> MSI|X ADDRESS 1 |
   1344 * +-----------------+    |     +----------------+           +-----------------+
   1345 * |       BAR1      |    |     |   Doorbell 2   +---------+ |                 |
   1346 * +-----------------+----+     +----------------+         | |                 |
   1347 * |       BAR2      |          |   Doorbell 3   +-------+ | +-----------------+
   1348 * +-----------------+----+     +----------------+       | +-> MSI|X ADDRESS 2 |
   1349 * |       BAR3      |    |     |   Doorbell 4   +-----+ |   +-----------------+
   1350 * +-----------------+    |     |----------------+     | |   |                 |
   1351 * |       BAR4      |    |     |                |     | |   +-----------------+
   1352 * +-----------------+    |     |      MW1       +---+ | +-->+ MSI|X ADDRESS 3||
   1353 * |       BAR5      |    |     |                |   | |     +-----------------+
   1354 * +-----------------+    +---->-----------------+   | |     |                 |
   1355 *   EP CONTROLLER 1            |                |   | |     +-----------------+
   1356 *                              |                |   | +---->+ MSI|X ADDRESS 4 |
   1357 *                              +----------------+   |       +-----------------+
   1358 *                      (A)      EP CONTROLLER 2     |       |                 |
   1359 *                                 (OB SPACE)        |       |                 |
   1360 *                                                   +------->      MW1        |
   1361 *                                                           |                 |
   1362 *                                                           |                 |
   1363 *                                                   (B)     +-----------------+
   1364 *                                                           |                 |
   1365 *                                                           |                 |
   1366 *                                                           |                 |
   1367 *                                                           |                 |
   1368 *                                                           |                 |
   1369 *                                                           +-----------------+
   1370 *                                                           PCI Address Space
   1371 *                                                           (Managed by HOST2)
   1372 *
   1373 * Allocate memory in OB space of EP CONTROLLER 2 in the above diagram. Allocate
   1374 * for Doorbell 1, Doorbell 2, Doorbell 3, Doorbell 4, MW1 (and MW2, MW3, MW4).
   1375 */
   1376static int epf_ntb_alloc_peer_mem(struct device *dev,
   1377				  struct epf_ntb_epc *ntb_epc,
   1378				  enum epf_ntb_bar bar,
   1379				  struct epf_ntb_epc *peer_ntb_epc,
   1380				  size_t size)
   1381{
   1382	const struct pci_epc_features *epc_features;
   1383	struct pci_epf_bar *epf_bar;
   1384	struct pci_epc *peer_epc;
   1385	phys_addr_t phys_addr;
   1386	void __iomem *mw_addr;
   1387	enum pci_barno barno;
   1388	size_t align;
   1389
   1390	epc_features = ntb_epc->epc_features;
   1391	align = epc_features->align;
   1392
   1393	if (size < 128)
   1394		size = 128;
   1395
   1396	if (align)
   1397		size = ALIGN(size, align);
   1398	else
   1399		size = roundup_pow_of_two(size);
   1400
   1401	peer_epc = peer_ntb_epc->epc;
   1402	mw_addr = pci_epc_mem_alloc_addr(peer_epc, &phys_addr, size);
   1403	if (!mw_addr) {
   1404		dev_err(dev, "%s intf: Failed to allocate OB address\n",
   1405			pci_epc_interface_string(peer_ntb_epc->type));
   1406		return -ENOMEM;
   1407	}
   1408
   1409	barno = ntb_epc->epf_ntb_bar[bar];
   1410	epf_bar = &ntb_epc->epf_bar[barno];
   1411	ntb_epc->mw_addr[barno] = mw_addr;
   1412
   1413	epf_bar->phys_addr = phys_addr;
   1414	epf_bar->size = size;
   1415	epf_bar->barno = barno;
   1416	epf_bar->flags = PCI_BASE_ADDRESS_MEM_TYPE_32;
   1417
   1418	return 0;
   1419}
   1420
   1421/**
   1422 * epf_ntb_db_mw_bar_init() - Configure Doorbell and Memory window BARs
   1423 * @ntb: NTB device that facilitates communication between HOST1 and HOST2
   1424 * @type: PRIMARY interface or SECONDARY interface
   1425 *
   1426 * Wrapper for epf_ntb_alloc_peer_mem() and pci_epc_set_bar() that allocates
   1427 * memory in OB address space of HOST2 and configures BAR of HOST1
   1428 */
   1429static int epf_ntb_db_mw_bar_init(struct epf_ntb *ntb,
   1430				  enum pci_epc_interface_type type)
   1431{
   1432	const struct pci_epc_features *epc_features;
   1433	struct epf_ntb_epc *peer_ntb_epc, *ntb_epc;
   1434	struct pci_epf_bar *epf_bar;
   1435	struct epf_ntb_ctrl *ctrl;
   1436	u32 num_mws, db_count;
   1437	enum epf_ntb_bar bar;
   1438	enum pci_barno barno;
   1439	u8 func_no, vfunc_no;
   1440	struct pci_epc *epc;
   1441	struct device *dev;
   1442	size_t align;
   1443	int ret, i;
   1444	u64 size;
   1445
   1446	ntb_epc = ntb->epc[type];
   1447	peer_ntb_epc = ntb->epc[!type];
   1448
   1449	dev = &ntb->epf->dev;
   1450	epc_features = ntb_epc->epc_features;
   1451	align = epc_features->align;
   1452	func_no = ntb_epc->func_no;
   1453	vfunc_no = ntb_epc->vfunc_no;
   1454	epc = ntb_epc->epc;
   1455	num_mws = ntb->num_mws;
   1456	db_count = ntb->db_count;
   1457
   1458	for (bar = BAR_DB_MW1, i = 0; i < num_mws; bar++, i++) {
   1459		if (bar == BAR_DB_MW1) {
   1460			align = align ? align : 4;
   1461			size = db_count * align;
   1462			size = ALIGN(size, ntb->mws_size[i]);
   1463			ctrl = ntb_epc->reg;
   1464			ctrl->mw1_offset = size;
   1465			size += ntb->mws_size[i];
   1466		} else {
   1467			size = ntb->mws_size[i];
   1468		}
   1469
   1470		ret = epf_ntb_alloc_peer_mem(dev, ntb_epc, bar,
   1471					     peer_ntb_epc, size);
   1472		if (ret) {
   1473			dev_err(dev, "%s intf: DoorBell mem alloc failed\n",
   1474				pci_epc_interface_string(type));
   1475			goto err_alloc_peer_mem;
   1476		}
   1477
   1478		barno = ntb_epc->epf_ntb_bar[bar];
   1479		epf_bar = &ntb_epc->epf_bar[barno];
   1480
   1481		ret = pci_epc_set_bar(epc, func_no, vfunc_no, epf_bar);
   1482		if (ret) {
   1483			dev_err(dev, "%s intf: DoorBell BAR set failed\n",
   1484				pci_epc_interface_string(type));
   1485			goto err_alloc_peer_mem;
   1486		}
   1487	}
   1488
   1489	return 0;
   1490
   1491err_alloc_peer_mem:
   1492	epf_ntb_db_mw_bar_cleanup(ntb, type);
   1493
   1494	return ret;
   1495}
   1496
   1497/**
   1498 * epf_ntb_epc_destroy_interface() - Cleanup NTB EPC interface
   1499 * @ntb: NTB device that facilitates communication between HOST1 and HOST2
   1500 * @type: PRIMARY interface or SECONDARY interface
   1501 *
   1502 * Unbind NTB function device from EPC and relinquish reference to pci_epc
   1503 * for each of the interface.
   1504 */
   1505static void epf_ntb_epc_destroy_interface(struct epf_ntb *ntb,
   1506					  enum pci_epc_interface_type type)
   1507{
   1508	struct epf_ntb_epc *ntb_epc;
   1509	struct pci_epc *epc;
   1510	struct pci_epf *epf;
   1511
   1512	if (type < 0)
   1513		return;
   1514
   1515	epf = ntb->epf;
   1516	ntb_epc = ntb->epc[type];
   1517	if (!ntb_epc)
   1518		return;
   1519	epc = ntb_epc->epc;
   1520	pci_epc_remove_epf(epc, epf, type);
   1521	pci_epc_put(epc);
   1522}
   1523
   1524/**
   1525 * epf_ntb_epc_destroy() - Cleanup NTB EPC interface
   1526 * @ntb: NTB device that facilitates communication between HOST1 and HOST2
   1527 *
   1528 * Wrapper for epf_ntb_epc_destroy_interface() to cleanup all the NTB interfaces
   1529 */
   1530static void epf_ntb_epc_destroy(struct epf_ntb *ntb)
   1531{
   1532	enum pci_epc_interface_type type;
   1533
   1534	for (type = PRIMARY_INTERFACE; type <= SECONDARY_INTERFACE; type++)
   1535		epf_ntb_epc_destroy_interface(ntb, type);
   1536}
   1537
   1538/**
   1539 * epf_ntb_epc_create_interface() - Create and initialize NTB EPC interface
   1540 * @ntb: NTB device that facilitates communication between HOST1 and HOST2
   1541 * @epc: struct pci_epc to which a particular NTB interface should be associated
   1542 * @type: PRIMARY interface or SECONDARY interface
   1543 *
   1544 * Allocate memory for NTB EPC interface and initialize it.
   1545 */
   1546static int epf_ntb_epc_create_interface(struct epf_ntb *ntb,
   1547					struct pci_epc *epc,
   1548					enum pci_epc_interface_type type)
   1549{
   1550	const struct pci_epc_features *epc_features;
   1551	struct pci_epf_bar *epf_bar;
   1552	struct epf_ntb_epc *ntb_epc;
   1553	u8 func_no, vfunc_no;
   1554	struct pci_epf *epf;
   1555	struct device *dev;
   1556
   1557	dev = &ntb->epf->dev;
   1558
   1559	ntb_epc = devm_kzalloc(dev, sizeof(*ntb_epc), GFP_KERNEL);
   1560	if (!ntb_epc)
   1561		return -ENOMEM;
   1562
   1563	epf = ntb->epf;
   1564	vfunc_no = epf->vfunc_no;
   1565	if (type == PRIMARY_INTERFACE) {
   1566		func_no = epf->func_no;
   1567		epf_bar = epf->bar;
   1568	} else {
   1569		func_no = epf->sec_epc_func_no;
   1570		epf_bar = epf->sec_epc_bar;
   1571	}
   1572
   1573	ntb_epc->linkup = false;
   1574	ntb_epc->epc = epc;
   1575	ntb_epc->func_no = func_no;
   1576	ntb_epc->vfunc_no = vfunc_no;
   1577	ntb_epc->type = type;
   1578	ntb_epc->epf_bar = epf_bar;
   1579	ntb_epc->epf_ntb = ntb;
   1580
   1581	epc_features = pci_epc_get_features(epc, func_no, vfunc_no);
   1582	if (!epc_features)
   1583		return -EINVAL;
   1584	ntb_epc->epc_features = epc_features;
   1585
   1586	ntb->epc[type] = ntb_epc;
   1587
   1588	return 0;
   1589}
   1590
   1591/**
   1592 * epf_ntb_epc_create() - Create and initialize NTB EPC interface
   1593 * @ntb: NTB device that facilitates communication between HOST1 and HOST2
   1594 *
   1595 * Get a reference to EPC device and bind NTB function device to that EPC
   1596 * for each of the interface. It is also a wrapper to
   1597 * epf_ntb_epc_create_interface() to allocate memory for NTB EPC interface
   1598 * and initialize it
   1599 */
   1600static int epf_ntb_epc_create(struct epf_ntb *ntb)
   1601{
   1602	struct pci_epf *epf;
   1603	struct device *dev;
   1604	int ret;
   1605
   1606	epf = ntb->epf;
   1607	dev = &epf->dev;
   1608
   1609	ret = epf_ntb_epc_create_interface(ntb, epf->epc, PRIMARY_INTERFACE);
   1610	if (ret) {
   1611		dev_err(dev, "PRIMARY intf: Fail to create NTB EPC\n");
   1612		return ret;
   1613	}
   1614
   1615	ret = epf_ntb_epc_create_interface(ntb, epf->sec_epc,
   1616					   SECONDARY_INTERFACE);
   1617	if (ret) {
   1618		dev_err(dev, "SECONDARY intf: Fail to create NTB EPC\n");
   1619		goto err_epc_create;
   1620	}
   1621
   1622	return 0;
   1623
   1624err_epc_create:
   1625	epf_ntb_epc_destroy_interface(ntb, PRIMARY_INTERFACE);
   1626
   1627	return ret;
   1628}
   1629
   1630/**
   1631 * epf_ntb_init_epc_bar_interface() - Identify BARs to be used for each of
   1632 *   the NTB constructs (scratchpad region, doorbell, memorywindow)
   1633 * @ntb: NTB device that facilitates communication between HOST1 and HOST2
   1634 * @type: PRIMARY interface or SECONDARY interface
   1635 *
   1636 * Identify the free BARs to be used for each of BAR_CONFIG, BAR_PEER_SPAD,
   1637 * BAR_DB_MW1, BAR_MW2, BAR_MW3 and BAR_MW4.
   1638 */
   1639static int epf_ntb_init_epc_bar_interface(struct epf_ntb *ntb,
   1640					  enum pci_epc_interface_type type)
   1641{
   1642	const struct pci_epc_features *epc_features;
   1643	struct epf_ntb_epc *ntb_epc;
   1644	enum pci_barno barno;
   1645	enum epf_ntb_bar bar;
   1646	struct device *dev;
   1647	u32 num_mws;
   1648	int i;
   1649
   1650	barno = BAR_0;
   1651	ntb_epc = ntb->epc[type];
   1652	num_mws = ntb->num_mws;
   1653	dev = &ntb->epf->dev;
   1654	epc_features = ntb_epc->epc_features;
   1655
   1656	/* These are required BARs which are mandatory for NTB functionality */
   1657	for (bar = BAR_CONFIG; bar <= BAR_DB_MW1; bar++, barno++) {
   1658		barno = pci_epc_get_next_free_bar(epc_features, barno);
   1659		if (barno < 0) {
   1660			dev_err(dev, "%s intf: Fail to get NTB function BAR\n",
   1661				pci_epc_interface_string(type));
   1662			return barno;
   1663		}
   1664		ntb_epc->epf_ntb_bar[bar] = barno;
   1665	}
   1666
   1667	/* These are optional BARs which don't impact NTB functionality */
   1668	for (bar = BAR_MW2, i = 1; i < num_mws; bar++, barno++, i++) {
   1669		barno = pci_epc_get_next_free_bar(epc_features, barno);
   1670		if (barno < 0) {
   1671			ntb->num_mws = i;
   1672			dev_dbg(dev, "BAR not available for > MW%d\n", i + 1);
   1673		}
   1674		ntb_epc->epf_ntb_bar[bar] = barno;
   1675	}
   1676
   1677	return 0;
   1678}
   1679
   1680/**
   1681 * epf_ntb_init_epc_bar() - Identify BARs to be used for each of the NTB
   1682 * constructs (scratchpad region, doorbell, memorywindow)
   1683 * @ntb: NTB device that facilitates communication between HOST1 and HOST2
   1684 *
   1685 * Wrapper to epf_ntb_init_epc_bar_interface() to identify the free BARs
   1686 * to be used for each of BAR_CONFIG, BAR_PEER_SPAD, BAR_DB_MW1, BAR_MW2,
   1687 * BAR_MW3 and BAR_MW4 for all the interfaces.
   1688 */
   1689static int epf_ntb_init_epc_bar(struct epf_ntb *ntb)
   1690{
   1691	enum pci_epc_interface_type type;
   1692	struct device *dev;
   1693	int ret;
   1694
   1695	dev = &ntb->epf->dev;
   1696	for (type = PRIMARY_INTERFACE; type <= SECONDARY_INTERFACE; type++) {
   1697		ret = epf_ntb_init_epc_bar_interface(ntb, type);
   1698		if (ret) {
   1699			dev_err(dev, "Fail to init EPC bar for %s interface\n",
   1700				pci_epc_interface_string(type));
   1701			return ret;
   1702		}
   1703	}
   1704
   1705	return 0;
   1706}
   1707
   1708/**
   1709 * epf_ntb_epc_init_interface() - Initialize NTB interface
   1710 * @ntb: NTB device that facilitates communication between HOST1 and HOST2
   1711 * @type: PRIMARY interface or SECONDARY interface
   1712 *
   1713 * Wrapper to initialize a particular EPC interface and start the workqueue
   1714 * to check for commands from host. This function will write to the
   1715 * EP controller HW for configuring it.
   1716 */
   1717static int epf_ntb_epc_init_interface(struct epf_ntb *ntb,
   1718				      enum pci_epc_interface_type type)
   1719{
   1720	struct epf_ntb_epc *ntb_epc;
   1721	u8 func_no, vfunc_no;
   1722	struct pci_epc *epc;
   1723	struct pci_epf *epf;
   1724	struct device *dev;
   1725	int ret;
   1726
   1727	ntb_epc = ntb->epc[type];
   1728	epf = ntb->epf;
   1729	dev = &epf->dev;
   1730	epc = ntb_epc->epc;
   1731	func_no = ntb_epc->func_no;
   1732	vfunc_no = ntb_epc->vfunc_no;
   1733
   1734	ret = epf_ntb_config_sspad_bar_set(ntb->epc[type]);
   1735	if (ret) {
   1736		dev_err(dev, "%s intf: Config/self SPAD BAR init failed\n",
   1737			pci_epc_interface_string(type));
   1738		return ret;
   1739	}
   1740
   1741	ret = epf_ntb_peer_spad_bar_set(ntb, type);
   1742	if (ret) {
   1743		dev_err(dev, "%s intf: Peer SPAD BAR init failed\n",
   1744			pci_epc_interface_string(type));
   1745		goto err_peer_spad_bar_init;
   1746	}
   1747
   1748	ret = epf_ntb_configure_interrupt(ntb, type);
   1749	if (ret) {
   1750		dev_err(dev, "%s intf: Interrupt configuration failed\n",
   1751			pci_epc_interface_string(type));
   1752		goto err_peer_spad_bar_init;
   1753	}
   1754
   1755	ret = epf_ntb_db_mw_bar_init(ntb, type);
   1756	if (ret) {
   1757		dev_err(dev, "%s intf: DB/MW BAR init failed\n",
   1758			pci_epc_interface_string(type));
   1759		goto err_db_mw_bar_init;
   1760	}
   1761
   1762	if (vfunc_no <= 1) {
   1763		ret = pci_epc_write_header(epc, func_no, vfunc_no, epf->header);
   1764		if (ret) {
   1765			dev_err(dev, "%s intf: Configuration header write failed\n",
   1766				pci_epc_interface_string(type));
   1767			goto err_write_header;
   1768		}
   1769	}
   1770
   1771	INIT_DELAYED_WORK(&ntb->epc[type]->cmd_handler, epf_ntb_cmd_handler);
   1772	queue_work(kpcintb_workqueue, &ntb->epc[type]->cmd_handler.work);
   1773
   1774	return 0;
   1775
   1776err_write_header:
   1777	epf_ntb_db_mw_bar_cleanup(ntb, type);
   1778
   1779err_db_mw_bar_init:
   1780	epf_ntb_peer_spad_bar_clear(ntb->epc[type]);
   1781
   1782err_peer_spad_bar_init:
   1783	epf_ntb_config_sspad_bar_clear(ntb->epc[type]);
   1784
   1785	return ret;
   1786}
   1787
   1788/**
   1789 * epf_ntb_epc_cleanup_interface() - Cleanup NTB interface
   1790 * @ntb: NTB device that facilitates communication between HOST1 and HOST2
   1791 * @type: PRIMARY interface or SECONDARY interface
   1792 *
   1793 * Wrapper to cleanup a particular NTB interface.
   1794 */
   1795static void epf_ntb_epc_cleanup_interface(struct epf_ntb *ntb,
   1796					  enum pci_epc_interface_type type)
   1797{
   1798	struct epf_ntb_epc *ntb_epc;
   1799
   1800	if (type < 0)
   1801		return;
   1802
   1803	ntb_epc = ntb->epc[type];
   1804	cancel_delayed_work(&ntb_epc->cmd_handler);
   1805	epf_ntb_db_mw_bar_cleanup(ntb, type);
   1806	epf_ntb_peer_spad_bar_clear(ntb_epc);
   1807	epf_ntb_config_sspad_bar_clear(ntb_epc);
   1808}
   1809
   1810/**
   1811 * epf_ntb_epc_cleanup() - Cleanup all NTB interfaces
   1812 * @ntb: NTB device that facilitates communication between HOST1 and HOST2
   1813 *
   1814 * Wrapper to cleanup all NTB interfaces.
   1815 */
   1816static void epf_ntb_epc_cleanup(struct epf_ntb *ntb)
   1817{
   1818	enum pci_epc_interface_type type;
   1819
   1820	for (type = PRIMARY_INTERFACE; type <= SECONDARY_INTERFACE; type++)
   1821		epf_ntb_epc_cleanup_interface(ntb, type);
   1822}
   1823
   1824/**
   1825 * epf_ntb_epc_init() - Initialize all NTB interfaces
   1826 * @ntb: NTB device that facilitates communication between HOST1 and HOST2
   1827 *
   1828 * Wrapper to initialize all NTB interface and start the workqueue
   1829 * to check for commands from host.
   1830 */
   1831static int epf_ntb_epc_init(struct epf_ntb *ntb)
   1832{
   1833	enum pci_epc_interface_type type;
   1834	struct device *dev;
   1835	int ret;
   1836
   1837	dev = &ntb->epf->dev;
   1838
   1839	for (type = PRIMARY_INTERFACE; type <= SECONDARY_INTERFACE; type++) {
   1840		ret = epf_ntb_epc_init_interface(ntb, type);
   1841		if (ret) {
   1842			dev_err(dev, "%s intf: Failed to initialize\n",
   1843				pci_epc_interface_string(type));
   1844			goto err_init_type;
   1845		}
   1846	}
   1847
   1848	return 0;
   1849
   1850err_init_type:
   1851	epf_ntb_epc_cleanup_interface(ntb, type - 1);
   1852
   1853	return ret;
   1854}
   1855
   1856/**
   1857 * epf_ntb_bind() - Initialize endpoint controller to provide NTB functionality
   1858 * @epf: NTB endpoint function device
   1859 *
   1860 * Initialize both the endpoint controllers associated with NTB function device.
   1861 * Invoked when a primary interface or secondary interface is bound to EPC
   1862 * device. This function will succeed only when EPC is bound to both the
   1863 * interfaces.
   1864 */
   1865static int epf_ntb_bind(struct pci_epf *epf)
   1866{
   1867	struct epf_ntb *ntb = epf_get_drvdata(epf);
   1868	struct device *dev = &epf->dev;
   1869	int ret;
   1870
   1871	if (!epf->epc) {
   1872		dev_dbg(dev, "PRIMARY EPC interface not yet bound\n");
   1873		return 0;
   1874	}
   1875
   1876	if (!epf->sec_epc) {
   1877		dev_dbg(dev, "SECONDARY EPC interface not yet bound\n");
   1878		return 0;
   1879	}
   1880
   1881	ret = epf_ntb_epc_create(ntb);
   1882	if (ret) {
   1883		dev_err(dev, "Failed to create NTB EPC\n");
   1884		return ret;
   1885	}
   1886
   1887	ret = epf_ntb_init_epc_bar(ntb);
   1888	if (ret) {
   1889		dev_err(dev, "Failed to create NTB EPC\n");
   1890		goto err_bar_init;
   1891	}
   1892
   1893	ret = epf_ntb_config_spad_bar_alloc_interface(ntb);
   1894	if (ret) {
   1895		dev_err(dev, "Failed to allocate BAR memory\n");
   1896		goto err_bar_alloc;
   1897	}
   1898
   1899	ret = epf_ntb_epc_init(ntb);
   1900	if (ret) {
   1901		dev_err(dev, "Failed to initialize EPC\n");
   1902		goto err_bar_alloc;
   1903	}
   1904
   1905	epf_set_drvdata(epf, ntb);
   1906
   1907	return 0;
   1908
   1909err_bar_alloc:
   1910	epf_ntb_config_spad_bar_free(ntb);
   1911
   1912err_bar_init:
   1913	epf_ntb_epc_destroy(ntb);
   1914
   1915	return ret;
   1916}
   1917
   1918/**
   1919 * epf_ntb_unbind() - Cleanup the initialization from epf_ntb_bind()
   1920 * @epf: NTB endpoint function device
   1921 *
   1922 * Cleanup the initialization from epf_ntb_bind()
   1923 */
   1924static void epf_ntb_unbind(struct pci_epf *epf)
   1925{
   1926	struct epf_ntb *ntb = epf_get_drvdata(epf);
   1927
   1928	epf_ntb_epc_cleanup(ntb);
   1929	epf_ntb_config_spad_bar_free(ntb);
   1930	epf_ntb_epc_destroy(ntb);
   1931}
   1932
   1933#define EPF_NTB_R(_name)						\
   1934static ssize_t epf_ntb_##_name##_show(struct config_item *item,		\
   1935				      char *page)			\
   1936{									\
   1937	struct config_group *group = to_config_group(item);		\
   1938	struct epf_ntb *ntb = to_epf_ntb(group);			\
   1939									\
   1940	return sysfs_emit(page, "%d\n", ntb->_name);			\
   1941}
   1942
   1943#define EPF_NTB_W(_name)						\
   1944static ssize_t epf_ntb_##_name##_store(struct config_item *item,	\
   1945				       const char *page, size_t len)	\
   1946{									\
   1947	struct config_group *group = to_config_group(item);		\
   1948	struct epf_ntb *ntb = to_epf_ntb(group);			\
   1949	u32 val;							\
   1950									\
   1951	if (kstrtou32(page, 0, &val) < 0)				\
   1952		return -EINVAL;						\
   1953									\
   1954	ntb->_name = val;						\
   1955									\
   1956	return len;							\
   1957}
   1958
   1959#define EPF_NTB_MW_R(_name)						\
   1960static ssize_t epf_ntb_##_name##_show(struct config_item *item,		\
   1961				      char *page)			\
   1962{									\
   1963	struct config_group *group = to_config_group(item);		\
   1964	struct epf_ntb *ntb = to_epf_ntb(group);			\
   1965	int win_no;							\
   1966									\
   1967	sscanf(#_name, "mw%d", &win_no);				\
   1968									\
   1969	return sysfs_emit(page, "%lld\n", ntb->mws_size[win_no - 1]);	\
   1970}
   1971
   1972#define EPF_NTB_MW_W(_name)						\
   1973static ssize_t epf_ntb_##_name##_store(struct config_item *item,	\
   1974				       const char *page, size_t len)	\
   1975{									\
   1976	struct config_group *group = to_config_group(item);		\
   1977	struct epf_ntb *ntb = to_epf_ntb(group);			\
   1978	struct device *dev = &ntb->epf->dev;				\
   1979	int win_no;							\
   1980	u64 val;							\
   1981									\
   1982	if (kstrtou64(page, 0, &val) < 0)				\
   1983		return -EINVAL;						\
   1984									\
   1985	if (sscanf(#_name, "mw%d", &win_no) != 1)			\
   1986		return -EINVAL;						\
   1987									\
   1988	if (ntb->num_mws < win_no) {					\
   1989		dev_err(dev, "Invalid num_nws: %d value\n", ntb->num_mws); \
   1990		return -EINVAL;						\
   1991	}								\
   1992									\
   1993	ntb->mws_size[win_no - 1] = val;				\
   1994									\
   1995	return len;							\
   1996}
   1997
   1998static ssize_t epf_ntb_num_mws_store(struct config_item *item,
   1999				     const char *page, size_t len)
   2000{
   2001	struct config_group *group = to_config_group(item);
   2002	struct epf_ntb *ntb = to_epf_ntb(group);
   2003	u32 val;
   2004
   2005	if (kstrtou32(page, 0, &val) < 0)
   2006		return -EINVAL;
   2007
   2008	if (val > MAX_MW)
   2009		return -EINVAL;
   2010
   2011	ntb->num_mws = val;
   2012
   2013	return len;
   2014}
   2015
   2016EPF_NTB_R(spad_count)
   2017EPF_NTB_W(spad_count)
   2018EPF_NTB_R(db_count)
   2019EPF_NTB_W(db_count)
   2020EPF_NTB_R(num_mws)
   2021EPF_NTB_MW_R(mw1)
   2022EPF_NTB_MW_W(mw1)
   2023EPF_NTB_MW_R(mw2)
   2024EPF_NTB_MW_W(mw2)
   2025EPF_NTB_MW_R(mw3)
   2026EPF_NTB_MW_W(mw3)
   2027EPF_NTB_MW_R(mw4)
   2028EPF_NTB_MW_W(mw4)
   2029
   2030CONFIGFS_ATTR(epf_ntb_, spad_count);
   2031CONFIGFS_ATTR(epf_ntb_, db_count);
   2032CONFIGFS_ATTR(epf_ntb_, num_mws);
   2033CONFIGFS_ATTR(epf_ntb_, mw1);
   2034CONFIGFS_ATTR(epf_ntb_, mw2);
   2035CONFIGFS_ATTR(epf_ntb_, mw3);
   2036CONFIGFS_ATTR(epf_ntb_, mw4);
   2037
   2038static struct configfs_attribute *epf_ntb_attrs[] = {
   2039	&epf_ntb_attr_spad_count,
   2040	&epf_ntb_attr_db_count,
   2041	&epf_ntb_attr_num_mws,
   2042	&epf_ntb_attr_mw1,
   2043	&epf_ntb_attr_mw2,
   2044	&epf_ntb_attr_mw3,
   2045	&epf_ntb_attr_mw4,
   2046	NULL,
   2047};
   2048
   2049static const struct config_item_type ntb_group_type = {
   2050	.ct_attrs	= epf_ntb_attrs,
   2051	.ct_owner	= THIS_MODULE,
   2052};
   2053
   2054/**
   2055 * epf_ntb_add_cfs() - Add configfs directory specific to NTB
   2056 * @epf: NTB endpoint function device
   2057 * @group: A pointer to the config_group structure referencing a group of
   2058 *	   config_items of a specific type that belong to a specific sub-system.
   2059 *
   2060 * Add configfs directory specific to NTB. This directory will hold
   2061 * NTB specific properties like db_count, spad_count, num_mws etc.,
   2062 */
   2063static struct config_group *epf_ntb_add_cfs(struct pci_epf *epf,
   2064					    struct config_group *group)
   2065{
   2066	struct epf_ntb *ntb = epf_get_drvdata(epf);
   2067	struct config_group *ntb_group = &ntb->group;
   2068	struct device *dev = &epf->dev;
   2069
   2070	config_group_init_type_name(ntb_group, dev_name(dev), &ntb_group_type);
   2071
   2072	return ntb_group;
   2073}
   2074
   2075/**
   2076 * epf_ntb_probe() - Probe NTB function driver
   2077 * @epf: NTB endpoint function device
   2078 *
   2079 * Probe NTB function driver when endpoint function bus detects a NTB
   2080 * endpoint function.
   2081 */
   2082static int epf_ntb_probe(struct pci_epf *epf)
   2083{
   2084	struct epf_ntb *ntb;
   2085	struct device *dev;
   2086
   2087	dev = &epf->dev;
   2088
   2089	ntb = devm_kzalloc(dev, sizeof(*ntb), GFP_KERNEL);
   2090	if (!ntb)
   2091		return -ENOMEM;
   2092
   2093	epf->header = &epf_ntb_header;
   2094	ntb->epf = epf;
   2095	epf_set_drvdata(epf, ntb);
   2096
   2097	return 0;
   2098}
   2099
   2100static struct pci_epf_ops epf_ntb_ops = {
   2101	.bind	= epf_ntb_bind,
   2102	.unbind	= epf_ntb_unbind,
   2103	.add_cfs = epf_ntb_add_cfs,
   2104};
   2105
   2106static const struct pci_epf_device_id epf_ntb_ids[] = {
   2107	{
   2108		.name = "pci_epf_ntb",
   2109	},
   2110	{},
   2111};
   2112
   2113static struct pci_epf_driver epf_ntb_driver = {
   2114	.driver.name	= "pci_epf_ntb",
   2115	.probe		= epf_ntb_probe,
   2116	.id_table	= epf_ntb_ids,
   2117	.ops		= &epf_ntb_ops,
   2118	.owner		= THIS_MODULE,
   2119};
   2120
   2121static int __init epf_ntb_init(void)
   2122{
   2123	int ret;
   2124
   2125	kpcintb_workqueue = alloc_workqueue("kpcintb", WQ_MEM_RECLAIM |
   2126					    WQ_HIGHPRI, 0);
   2127	ret = pci_epf_register_driver(&epf_ntb_driver);
   2128	if (ret) {
   2129		destroy_workqueue(kpcintb_workqueue);
   2130		pr_err("Failed to register pci epf ntb driver --> %d\n", ret);
   2131		return ret;
   2132	}
   2133
   2134	return 0;
   2135}
   2136module_init(epf_ntb_init);
   2137
   2138static void __exit epf_ntb_exit(void)
   2139{
   2140	pci_epf_unregister_driver(&epf_ntb_driver);
   2141	destroy_workqueue(kpcintb_workqueue);
   2142}
   2143module_exit(epf_ntb_exit);
   2144
   2145MODULE_DESCRIPTION("PCI EPF NTB DRIVER");
   2146MODULE_AUTHOR("Kishon Vijay Abraham I <kishon@ti.com>");
   2147MODULE_LICENSE("GPL v2");