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	struct epf_ntb_epc *ntb_epc;
144	struct epf_ntb_ctrl *ctrl;
145	unsigned int irq_type;
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_IRQ_MSIX : PCI_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[barno].fixed_size;
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[peer_barno].fixed_size;
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, epc_features, 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 * @id: NTB endpoint function device ID
2079 *
2080 * Probe NTB function driver when endpoint function bus detects a NTB
2081 * endpoint function.
2082 */
2083static int epf_ntb_probe(struct pci_epf *epf,
2084			 const struct pci_epf_device_id *id)
2085{
2086	struct epf_ntb *ntb;
2087	struct device *dev;
2088
2089	dev = &epf->dev;
2090
2091	ntb = devm_kzalloc(dev, sizeof(*ntb), GFP_KERNEL);
2092	if (!ntb)
2093		return -ENOMEM;
2094
2095	epf->header = &epf_ntb_header;
2096	ntb->epf = epf;
2097	epf_set_drvdata(epf, ntb);
2098
2099	return 0;
2100}
2101
2102static const struct pci_epf_ops epf_ntb_ops = {
2103	.bind	= epf_ntb_bind,
2104	.unbind	= epf_ntb_unbind,
2105	.add_cfs = epf_ntb_add_cfs,
2106};
2107
2108static const struct pci_epf_device_id epf_ntb_ids[] = {
2109	{
2110		.name = "pci_epf_ntb",
2111	},
2112	{},
2113};
2114
2115static struct pci_epf_driver epf_ntb_driver = {
2116	.driver.name	= "pci_epf_ntb",
2117	.probe		= epf_ntb_probe,
2118	.id_table	= epf_ntb_ids,
2119	.ops		= &epf_ntb_ops,
2120	.owner		= THIS_MODULE,
2121};
2122
2123static int __init epf_ntb_init(void)
2124{
2125	int ret;
2126
2127	kpcintb_workqueue = alloc_workqueue("kpcintb", WQ_MEM_RECLAIM |
2128					    WQ_HIGHPRI, 0);
2129	ret = pci_epf_register_driver(&epf_ntb_driver);
2130	if (ret) {
2131		destroy_workqueue(kpcintb_workqueue);
2132		pr_err("Failed to register pci epf ntb driver --> %d\n", ret);
2133		return ret;
2134	}
2135
2136	return 0;
2137}
2138module_init(epf_ntb_init);
2139
2140static void __exit epf_ntb_exit(void)
2141{
2142	pci_epf_unregister_driver(&epf_ntb_driver);
2143	destroy_workqueue(kpcintb_workqueue);
2144}
2145module_exit(epf_ntb_exit);
2146
2147MODULE_DESCRIPTION("PCI EPF NTB DRIVER");
2148MODULE_AUTHOR("Kishon Vijay Abraham I <kishon@ti.com>");
2149MODULE_LICENSE("GPL v2");
2150