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