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_epc: EPC associated with one of the HOST which holds peer's outbound
700  *	     address.
701  *
702  *+-----------------+------->+------------------+        +-----------------+
703  *|       BAR0      |        |  CONFIG REGION   |        |       BAR0      |
704  *+-----------------+----+   +------------------+<-------+-----------------+
705  *|       BAR1      |    |   |SCRATCHPAD REGION |        |       BAR1      |
706  *+-----------------+    +-->+------------------+<-------+-----------------+
707  *|       BAR2      |            Local Memory            |       BAR2      |
708  *+-----------------+                                    +-----------------+
709  *|       BAR3      |                                    |       BAR3      |
710  *+-----------------+                                    +-----------------+
711  *|       BAR4      |                                    |       BAR4      |
712  *+-----------------+                                    +-----------------+
713  *|       BAR5      |                                    |       BAR5      |
714  *+-----------------+                                    +-----------------+
715  *  EP CONTROLLER 1                                        EP CONTROLLER 2
716  *
717  * Clear BAR1 of EP CONTROLLER 2 which contains the HOST2's peer scratchpad
718  * region. While BAR1 is the default peer scratchpad BAR, an NTB could have
719  * other BARs for peer scratchpad (because of 64-bit BARs or reserved BARs).
720  * This function can get the exact BAR used for peer scratchpad from
721  * epf_ntb_bar[BAR_PEER_SPAD].
722  *
723  * Since HOST2's peer scratchpad is also HOST1's self scratchpad, this function
724  * gets the address of peer scratchpad from
725  * peer_ntb_epc->epf_ntb_bar[BAR_CONFIG].
726  */
727 static void epf_ntb_peer_spad_bar_clear(struct epf_ntb_epc *ntb_epc)
728 {
729 	struct pci_epf_bar *epf_bar;
730 	enum pci_barno barno;
731 	struct pci_epc *epc;
732 	u8 func_no;
733 
734 	epc = ntb_epc->epc;
735 	func_no = ntb_epc->func_no;
736 	barno = ntb_epc->epf_ntb_bar[BAR_PEER_SPAD];
737 	epf_bar = &ntb_epc->epf_bar[barno];
738 	pci_epc_clear_bar(epc, func_no, epf_bar);
739 }
740 
741 /**
742  * epf_ntb_peer_spad_bar_set() - Set peer scratchpad BAR
743  * @ntb: NTB device that facilitates communication between HOST1 and HOST2
744  * @type: PRIMARY interface or SECONDARY interface
745  *
746  *+-----------------+------->+------------------+        +-----------------+
747  *|       BAR0      |        |  CONFIG REGION   |        |       BAR0      |
748  *+-----------------+----+   +------------------+<-------+-----------------+
749  *|       BAR1      |    |   |SCRATCHPAD REGION |        |       BAR1      |
750  *+-----------------+    +-->+------------------+<-------+-----------------+
751  *|       BAR2      |            Local Memory            |       BAR2      |
752  *+-----------------+                                    +-----------------+
753  *|       BAR3      |                                    |       BAR3      |
754  *+-----------------+                                    +-----------------+
755  *|       BAR4      |                                    |       BAR4      |
756  *+-----------------+                                    +-----------------+
757  *|       BAR5      |                                    |       BAR5      |
758  *+-----------------+                                    +-----------------+
759  *  EP CONTROLLER 1                                        EP CONTROLLER 2
760  *
761  * Set BAR1 of EP CONTROLLER 2 which contains the HOST2's peer scratchpad
762  * region. While BAR1 is the default peer scratchpad BAR, an NTB could have
763  * other BARs for peer scratchpad (because of 64-bit BARs or reserved BARs).
764  * This function can get the exact BAR used for peer scratchpad from
765  * epf_ntb_bar[BAR_PEER_SPAD].
766  *
767  * Since HOST2's peer scratchpad is also HOST1's self scratchpad, this function
768  * gets the address of peer scratchpad from
769  * peer_ntb_epc->epf_ntb_bar[BAR_CONFIG].
770  */
771 static int epf_ntb_peer_spad_bar_set(struct epf_ntb *ntb,
772 				     enum pci_epc_interface_type type)
773 {
774 	struct epf_ntb_epc *peer_ntb_epc, *ntb_epc;
775 	struct pci_epf_bar *peer_epf_bar, *epf_bar;
776 	enum pci_barno peer_barno, barno;
777 	u32 peer_spad_offset;
778 	struct pci_epc *epc;
779 	struct device *dev;
780 	u8 func_no;
781 	int ret;
782 
783 	dev = &ntb->epf->dev;
784 
785 	peer_ntb_epc = ntb->epc[!type];
786 	peer_barno = peer_ntb_epc->epf_ntb_bar[BAR_CONFIG];
787 	peer_epf_bar = &peer_ntb_epc->epf_bar[peer_barno];
788 
789 	ntb_epc = ntb->epc[type];
790 	barno = ntb_epc->epf_ntb_bar[BAR_PEER_SPAD];
791 	epf_bar = &ntb_epc->epf_bar[barno];
792 	func_no = ntb_epc->func_no;
793 	epc = ntb_epc->epc;
794 
795 	peer_spad_offset = peer_ntb_epc->reg->spad_offset;
796 	epf_bar->phys_addr = peer_epf_bar->phys_addr + peer_spad_offset;
797 	epf_bar->size = peer_ntb_epc->spad_size;
798 	epf_bar->barno = barno;
799 	epf_bar->flags = PCI_BASE_ADDRESS_MEM_TYPE_32;
800 
801 	ret = pci_epc_set_bar(epc, func_no, epf_bar);
802 	if (ret) {
803 		dev_err(dev, "%s intf: peer SPAD BAR set failed\n",
804 			pci_epc_interface_string(type));
805 		return ret;
806 	}
807 
808 	return 0;
809 }
810 
811 /**
812  * epf_ntb_config_sspad_bar_clear() - Clear Config + Self scratchpad BAR
813  * @ntb_epc: EPC associated with one of the HOST which holds peer's outbound
814  *	     address.
815  *
816  * +-----------------+------->+------------------+        +-----------------+
817  * |       BAR0      |        |  CONFIG REGION   |        |       BAR0      |
818  * +-----------------+----+   +------------------+<-------+-----------------+
819  * |       BAR1      |    |   |SCRATCHPAD REGION |        |       BAR1      |
820  * +-----------------+    +-->+------------------+<-------+-----------------+
821  * |       BAR2      |            Local Memory            |       BAR2      |
822  * +-----------------+                                    +-----------------+
823  * |       BAR3      |                                    |       BAR3      |
824  * +-----------------+                                    +-----------------+
825  * |       BAR4      |                                    |       BAR4      |
826  * +-----------------+                                    +-----------------+
827  * |       BAR5      |                                    |       BAR5      |
828  * +-----------------+                                    +-----------------+
829  *   EP CONTROLLER 1                                        EP CONTROLLER 2
830  *
831  * Clear BAR0 of EP CONTROLLER 1 which contains the HOST1's config and
832  * self scratchpad region (removes inbound ATU configuration). While BAR0 is
833  * the default self scratchpad BAR, an NTB could have other BARs for self
834  * scratchpad (because of reserved BARs). This function can get the exact BAR
835  * used for self scratchpad from epf_ntb_bar[BAR_CONFIG].
836  *
837  * Please note the self scratchpad region and config region is combined to
838  * a single region and mapped using the same BAR. Also note HOST2's peer
839  * scratchpad is HOST1's self scratchpad.
840  */
841 static void epf_ntb_config_sspad_bar_clear(struct epf_ntb_epc *ntb_epc)
842 {
843 	struct pci_epf_bar *epf_bar;
844 	enum pci_barno barno;
845 	struct pci_epc *epc;
846 	u8 func_no;
847 
848 	epc = ntb_epc->epc;
849 	func_no = ntb_epc->func_no;
850 	barno = ntb_epc->epf_ntb_bar[BAR_CONFIG];
851 	epf_bar = &ntb_epc->epf_bar[barno];
852 	pci_epc_clear_bar(epc, func_no, epf_bar);
853 }
854 
855 /**
856  * epf_ntb_config_sspad_bar_set() - Set Config + Self scratchpad BAR
857  * @ntb_epc: EPC associated with one of the HOST which holds peer's outbound
858  *	     address.
859  *
860  * +-----------------+------->+------------------+        +-----------------+
861  * |       BAR0      |        |  CONFIG REGION   |        |       BAR0      |
862  * +-----------------+----+   +------------------+<-------+-----------------+
863  * |       BAR1      |    |   |SCRATCHPAD REGION |        |       BAR1      |
864  * +-----------------+    +-->+------------------+<-------+-----------------+
865  * |       BAR2      |            Local Memory            |       BAR2      |
866  * +-----------------+                                    +-----------------+
867  * |       BAR3      |                                    |       BAR3      |
868  * +-----------------+                                    +-----------------+
869  * |       BAR4      |                                    |       BAR4      |
870  * +-----------------+                                    +-----------------+
871  * |       BAR5      |                                    |       BAR5      |
872  * +-----------------+                                    +-----------------+
873  *   EP CONTROLLER 1                                        EP CONTROLLER 2
874  *
875  * Map BAR0 of EP CONTROLLER 1 which contains the HOST1's config and
876  * self scratchpad region. While BAR0 is the default self scratchpad BAR, an
877  * NTB could have other BARs for self scratchpad (because of reserved BARs).
878  * This function can get the exact BAR used for self scratchpad from
879  * epf_ntb_bar[BAR_CONFIG].
880  *
881  * Please note the self scratchpad region and config region is combined to
882  * a single region and mapped using the same BAR. Also note HOST2's peer
883  * scratchpad is HOST1's self scratchpad.
884  */
885 static int epf_ntb_config_sspad_bar_set(struct epf_ntb_epc *ntb_epc)
886 {
887 	struct pci_epf_bar *epf_bar;
888 	enum pci_barno barno;
889 	struct epf_ntb *ntb;
890 	struct pci_epc *epc;
891 	struct device *dev;
892 	u8 func_no;
893 	int ret;
894 
895 	ntb = ntb_epc->epf_ntb;
896 	dev = &ntb->epf->dev;
897 
898 	epc = ntb_epc->epc;
899 	func_no = ntb_epc->func_no;
900 	barno = ntb_epc->epf_ntb_bar[BAR_CONFIG];
901 	epf_bar = &ntb_epc->epf_bar[barno];
902 
903 	ret = pci_epc_set_bar(epc, func_no, epf_bar);
904 	if (ret) {
905 		dev_err(dev, "%s inft: Config/Status/SPAD BAR set failed\n",
906 			pci_epc_interface_string(ntb_epc->type));
907 		return ret;
908 	}
909 
910 	return 0;
911 }
912 
913 /**
914  * epf_ntb_config_spad_bar_free() - Free the physical memory associated with
915  *   config + scratchpad region
916  * @ntb: NTB device that facilitates communication between HOST1 and HOST2
917  *
918  * +-----------------+------->+------------------+        +-----------------+
919  * |       BAR0      |        |  CONFIG REGION   |        |       BAR0      |
920  * +-----------------+----+   +------------------+<-------+-----------------+
921  * |       BAR1      |    |   |SCRATCHPAD REGION |        |       BAR1      |
922  * +-----------------+    +-->+------------------+<-------+-----------------+
923  * |       BAR2      |            Local Memory            |       BAR2      |
924  * +-----------------+                                    +-----------------+
925  * |       BAR3      |                                    |       BAR3      |
926  * +-----------------+                                    +-----------------+
927  * |       BAR4      |                                    |       BAR4      |
928  * +-----------------+                                    +-----------------+
929  * |       BAR5      |                                    |       BAR5      |
930  * +-----------------+                                    +-----------------+
931  *   EP CONTROLLER 1                                        EP CONTROLLER 2
932  *
933  * Free the Local Memory mentioned in the above diagram. After invoking this
934  * function, any of config + self scratchpad region of HOST1 or peer scratchpad
935  * region of HOST2 should not be accessed.
936  */
937 static void epf_ntb_config_spad_bar_free(struct epf_ntb *ntb)
938 {
939 	enum pci_epc_interface_type type;
940 	struct epf_ntb_epc *ntb_epc;
941 	enum pci_barno barno;
942 	struct pci_epf *epf;
943 
944 	epf = ntb->epf;
945 	for (type = PRIMARY_INTERFACE; type <= SECONDARY_INTERFACE; type++) {
946 		ntb_epc = ntb->epc[type];
947 		barno = ntb_epc->epf_ntb_bar[BAR_CONFIG];
948 		if (ntb_epc->reg)
949 			pci_epf_free_space(epf, ntb_epc->reg, barno, type);
950 	}
951 }
952 
953 /**
954  * epf_ntb_config_spad_bar_alloc() - Allocate memory for config + scratchpad
955  *   region
956  * @ntb: NTB device that facilitates communication between HOST1 and HOST2
957  * @type: PRIMARY interface or SECONDARY interface
958  *
959  * +-----------------+------->+------------------+        +-----------------+
960  * |       BAR0      |        |  CONFIG REGION   |        |       BAR0      |
961  * +-----------------+----+   +------------------+<-------+-----------------+
962  * |       BAR1      |    |   |SCRATCHPAD REGION |        |       BAR1      |
963  * +-----------------+    +-->+------------------+<-------+-----------------+
964  * |       BAR2      |            Local Memory            |       BAR2      |
965  * +-----------------+                                    +-----------------+
966  * |       BAR3      |                                    |       BAR3      |
967  * +-----------------+                                    +-----------------+
968  * |       BAR4      |                                    |       BAR4      |
969  * +-----------------+                                    +-----------------+
970  * |       BAR5      |                                    |       BAR5      |
971  * +-----------------+                                    +-----------------+
972  *   EP CONTROLLER 1                                        EP CONTROLLER 2
973  *
974  * Allocate the Local Memory mentioned in the above diagram. The size of
975  * CONFIG REGION is sizeof(struct epf_ntb_ctrl) and size of SCRATCHPAD REGION
976  * is obtained from "spad-count" configfs entry.
977  *
978  * The size of both config region and scratchpad region has to be aligned,
979  * since the scratchpad region will also be mapped as PEER SCRATCHPAD of
980  * other host using a separate BAR.
981  */
982 static int epf_ntb_config_spad_bar_alloc(struct epf_ntb *ntb,
983 					 enum pci_epc_interface_type type)
984 {
985 	const struct pci_epc_features *peer_epc_features, *epc_features;
986 	struct epf_ntb_epc *peer_ntb_epc, *ntb_epc;
987 	size_t msix_table_size, pba_size, align;
988 	enum pci_barno peer_barno, barno;
989 	struct epf_ntb_ctrl *ctrl;
990 	u32 spad_size, ctrl_size;
991 	u64 size, peer_size;
992 	struct pci_epf *epf;
993 	struct device *dev;
994 	bool msix_capable;
995 	u32 spad_count;
996 	void *base;
997 
998 	epf = ntb->epf;
999 	dev = &epf->dev;
1000 	ntb_epc = ntb->epc[type];
1001 
1002 	epc_features = ntb_epc->epc_features;
1003 	barno = ntb_epc->epf_ntb_bar[BAR_CONFIG];
1004 	size = epc_features->bar_fixed_size[barno];
1005 	align = epc_features->align;
1006 
1007 	peer_ntb_epc = ntb->epc[!type];
1008 	peer_epc_features = peer_ntb_epc->epc_features;
1009 	peer_barno = ntb_epc->epf_ntb_bar[BAR_PEER_SPAD];
1010 	peer_size = peer_epc_features->bar_fixed_size[peer_barno];
1011 
1012 	/* Check if epc_features is populated incorrectly */
1013 	if ((!IS_ALIGNED(size, align)))
1014 		return -EINVAL;
1015 
1016 	spad_count = ntb->spad_count;
1017 
1018 	ctrl_size = sizeof(struct epf_ntb_ctrl);
1019 	spad_size = spad_count * 4;
1020 
1021 	msix_capable = epc_features->msix_capable;
1022 	if (msix_capable) {
1023 		msix_table_size = PCI_MSIX_ENTRY_SIZE * ntb->db_count;
1024 		ctrl_size = ALIGN(ctrl_size, 8);
1025 		ntb_epc->msix_table_offset = ctrl_size;
1026 		ntb_epc->msix_bar = barno;
1027 		/* Align to QWORD or 8 Bytes */
1028 		pba_size = ALIGN(DIV_ROUND_UP(ntb->db_count, 8), 8);
1029 		ctrl_size = ctrl_size + msix_table_size + pba_size;
1030 	}
1031 
1032 	if (!align) {
1033 		ctrl_size = roundup_pow_of_two(ctrl_size);
1034 		spad_size = roundup_pow_of_two(spad_size);
1035 	} else {
1036 		ctrl_size = ALIGN(ctrl_size, align);
1037 		spad_size = ALIGN(spad_size, align);
1038 	}
1039 
1040 	if (peer_size) {
1041 		if (peer_size < spad_size)
1042 			spad_count = peer_size / 4;
1043 		spad_size = peer_size;
1044 	}
1045 
1046 	/*
1047 	 * In order to make sure SPAD offset is aligned to its size,
1048 	 * expand control region size to the size of SPAD if SPAD size
1049 	 * is greater than control region size.
1050 	 */
1051 	if (spad_size > ctrl_size)
1052 		ctrl_size = spad_size;
1053 
1054 	if (!size)
1055 		size = ctrl_size + spad_size;
1056 	else if (size < ctrl_size + spad_size)
1057 		return -EINVAL;
1058 
1059 	base = pci_epf_alloc_space(epf, size, barno, align, type);
1060 	if (!base) {
1061 		dev_err(dev, "%s intf: Config/Status/SPAD alloc region fail\n",
1062 			pci_epc_interface_string(type));
1063 		return -ENOMEM;
1064 	}
1065 
1066 	ntb_epc->reg = base;
1067 
1068 	ctrl = ntb_epc->reg;
1069 	ctrl->spad_offset = ctrl_size;
1070 	ctrl->spad_count = spad_count;
1071 	ctrl->num_mws = ntb->num_mws;
1072 	ctrl->db_entry_size = align ? align : 4;
1073 	ntb_epc->spad_size = spad_size;
1074 
1075 	return 0;
1076 }
1077 
1078 /**
1079  * epf_ntb_config_spad_bar_alloc_interface() - Allocate memory for config +
1080  *   scratchpad region for each of PRIMARY and SECONDARY interface
1081  * @ntb: NTB device that facilitates communication between HOST1 and HOST2
1082  *
1083  * Wrapper for epf_ntb_config_spad_bar_alloc() which allocates memory for
1084  * config + scratchpad region for a specific interface
1085  */
1086 static int epf_ntb_config_spad_bar_alloc_interface(struct epf_ntb *ntb)
1087 {
1088 	enum pci_epc_interface_type type;
1089 	struct device *dev;
1090 	int ret;
1091 
1092 	dev = &ntb->epf->dev;
1093 
1094 	for (type = PRIMARY_INTERFACE; type <= SECONDARY_INTERFACE; type++) {
1095 		ret = epf_ntb_config_spad_bar_alloc(ntb, type);
1096 		if (ret) {
1097 			dev_err(dev, "%s intf: Config/SPAD BAR alloc failed\n",
1098 				pci_epc_interface_string(type));
1099 			return ret;
1100 		}
1101 	}
1102 
1103 	return 0;
1104 }
1105 
1106 /**
1107  * epf_ntb_free_peer_mem() - Free memory allocated in peers outbound address
1108  *   space
1109  * @ntb_epc: EPC associated with one of the HOST which holds peers outbound
1110  *   address regions
1111  *
1112  * +-----------------+    +---->+----------------+-----------+-----------------+
1113  * |       BAR0      |    |     |   Doorbell 1   +-----------> MSI|X ADDRESS 1 |
1114  * +-----------------+    |     +----------------+           +-----------------+
1115  * |       BAR1      |    |     |   Doorbell 2   +---------+ |                 |
1116  * +-----------------+----+     +----------------+         | |                 |
1117  * |       BAR2      |          |   Doorbell 3   +-------+ | +-----------------+
1118  * +-----------------+----+     +----------------+       | +-> MSI|X ADDRESS 2 |
1119  * |       BAR3      |    |     |   Doorbell 4   +-----+ |   +-----------------+
1120  * +-----------------+    |     |----------------+     | |   |                 |
1121  * |       BAR4      |    |     |                |     | |   +-----------------+
1122  * +-----------------+    |     |      MW1       +---+ | +-->+ MSI|X ADDRESS 3||
1123  * |       BAR5      |    |     |                |   | |     +-----------------+
1124  * +-----------------+    +---->-----------------+   | |     |                 |
1125  *   EP CONTROLLER 1            |                |   | |     +-----------------+
1126  *                              |                |   | +---->+ MSI|X ADDRESS 4 |
1127  *                              +----------------+   |       +-----------------+
1128  *                      (A)      EP CONTROLLER 2     |       |                 |
1129  *                                 (OB SPACE)        |       |                 |
1130  *                                                   +------->      MW1        |
1131  *                                                           |                 |
1132  *                                                           |                 |
1133  *                                                   (B)     +-----------------+
1134  *                                                           |                 |
1135  *                                                           |                 |
1136  *                                                           |                 |
1137  *                                                           |                 |
1138  *                                                           |                 |
1139  *                                                           +-----------------+
1140  *                                                           PCI Address Space
1141  *                                                           (Managed by HOST2)
1142  *
1143  * Free memory allocated in EP CONTROLLER 2 (OB SPACE) in the above diagram.
1144  * It'll free Doorbell 1, Doorbell 2, Doorbell 3, Doorbell 4, MW1 (and MW2, MW3,
1145  * MW4).
1146  */
1147 static void epf_ntb_free_peer_mem(struct epf_ntb_epc *ntb_epc)
1148 {
1149 	struct pci_epf_bar *epf_bar;
1150 	void __iomem *mw_addr;
1151 	phys_addr_t phys_addr;
1152 	enum epf_ntb_bar bar;
1153 	enum pci_barno barno;
1154 	struct pci_epc *epc;
1155 	size_t size;
1156 
1157 	epc = ntb_epc->epc;
1158 
1159 	for (bar = BAR_DB_MW1; bar < BAR_MW4; bar++) {
1160 		barno = ntb_epc->epf_ntb_bar[bar];
1161 		mw_addr = ntb_epc->mw_addr[barno];
1162 		epf_bar = &ntb_epc->epf_bar[barno];
1163 		phys_addr = epf_bar->phys_addr;
1164 		size = epf_bar->size;
1165 		if (mw_addr) {
1166 			pci_epc_mem_free_addr(epc, phys_addr, mw_addr, size);
1167 			ntb_epc->mw_addr[barno] = NULL;
1168 		}
1169 	}
1170 }
1171 
1172 /**
1173  * epf_ntb_db_mw_bar_clear() - Clear doorbell and memory BAR
1174  * @ntb_epc: EPC associated with one of the HOST which holds peer's outbound
1175  *   address
1176  *
1177  * +-----------------+    +---->+----------------+-----------+-----------------+
1178  * |       BAR0      |    |     |   Doorbell 1   +-----------> MSI|X ADDRESS 1 |
1179  * +-----------------+    |     +----------------+           +-----------------+
1180  * |       BAR1      |    |     |   Doorbell 2   +---------+ |                 |
1181  * +-----------------+----+     +----------------+         | |                 |
1182  * |       BAR2      |          |   Doorbell 3   +-------+ | +-----------------+
1183  * +-----------------+----+     +----------------+       | +-> MSI|X ADDRESS 2 |
1184  * |       BAR3      |    |     |   Doorbell 4   +-----+ |   +-----------------+
1185  * +-----------------+    |     |----------------+     | |   |                 |
1186  * |       BAR4      |    |     |                |     | |   +-----------------+
1187  * +-----------------+    |     |      MW1       +---+ | +-->+ MSI|X ADDRESS 3||
1188  * |       BAR5      |    |     |                |   | |     +-----------------+
1189  * +-----------------+    +---->-----------------+   | |     |                 |
1190  *   EP CONTROLLER 1            |                |   | |     +-----------------+
1191  *                              |                |   | +---->+ MSI|X ADDRESS 4 |
1192  *                              +----------------+   |       +-----------------+
1193  *                      (A)      EP CONTROLLER 2     |       |                 |
1194  *                                 (OB SPACE)        |       |                 |
1195  *                                                   +------->      MW1        |
1196  *                                                           |                 |
1197  *                                                           |                 |
1198  *                                                   (B)     +-----------------+
1199  *                                                           |                 |
1200  *                                                           |                 |
1201  *                                                           |                 |
1202  *                                                           |                 |
1203  *                                                           |                 |
1204  *                                                           +-----------------+
1205  *                                                           PCI Address Space
1206  *                                                           (Managed by HOST2)
1207  *
1208  * Clear doorbell and memory BARs (remove inbound ATU configuration). In the above
1209  * diagram it clears BAR2 TO BAR5 of EP CONTROLLER 1 (Doorbell BAR, MW1 BAR, MW2
1210  * BAR, MW3 BAR and MW4 BAR).
1211  */
1212 static void epf_ntb_db_mw_bar_clear(struct epf_ntb_epc *ntb_epc)
1213 {
1214 	struct pci_epf_bar *epf_bar;
1215 	enum epf_ntb_bar bar;
1216 	enum pci_barno barno;
1217 	struct pci_epc *epc;
1218 	u8 func_no;
1219 
1220 	epc = ntb_epc->epc;
1221 
1222 	func_no = ntb_epc->func_no;
1223 
1224 	for (bar = BAR_DB_MW1; bar < BAR_MW4; bar++) {
1225 		barno = ntb_epc->epf_ntb_bar[bar];
1226 		epf_bar = &ntb_epc->epf_bar[barno];
1227 		pci_epc_clear_bar(epc, func_no, epf_bar);
1228 	}
1229 }
1230 
1231 /**
1232  * epf_ntb_db_mw_bar_cleanup() - Clear doorbell/memory BAR and free memory
1233  *   allocated in peers outbound address space
1234  * @ntb: NTB device that facilitates communication between HOST1 and HOST2
1235  * @type: PRIMARY interface or SECONDARY interface
1236  *
1237  * Wrapper for epf_ntb_db_mw_bar_clear() to clear HOST1's BAR and
1238  * epf_ntb_free_peer_mem() which frees up HOST2 outbound memory.
1239  */
1240 static void epf_ntb_db_mw_bar_cleanup(struct epf_ntb *ntb,
1241 				      enum pci_epc_interface_type type)
1242 {
1243 	struct epf_ntb_epc *peer_ntb_epc, *ntb_epc;
1244 
1245 	ntb_epc = ntb->epc[type];
1246 	peer_ntb_epc = ntb->epc[!type];
1247 
1248 	epf_ntb_db_mw_bar_clear(ntb_epc);
1249 	epf_ntb_free_peer_mem(peer_ntb_epc);
1250 }
1251 
1252 /**
1253  * epf_ntb_configure_interrupt() - Configure MSI/MSI-X capaiblity
1254  * @ntb: NTB device that facilitates communication between HOST1 and HOST2
1255  * @type: PRIMARY interface or SECONDARY interface
1256  *
1257  * Configure MSI/MSI-X capability for each interface with number of
1258  * interrupts equal to "db_count" configfs entry.
1259  */
1260 static int epf_ntb_configure_interrupt(struct epf_ntb *ntb,
1261 				       enum pci_epc_interface_type type)
1262 {
1263 	const struct pci_epc_features *epc_features;
1264 	bool msix_capable, msi_capable;
1265 	struct epf_ntb_epc *ntb_epc;
1266 	struct pci_epc *epc;
1267 	struct device *dev;
1268 	u32 db_count;
1269 	u8 func_no;
1270 	int ret;
1271 
1272 	ntb_epc = ntb->epc[type];
1273 	dev = &ntb->epf->dev;
1274 
1275 	epc_features = ntb_epc->epc_features;
1276 	msix_capable = epc_features->msix_capable;
1277 	msi_capable = epc_features->msi_capable;
1278 
1279 	if (!(msix_capable || msi_capable)) {
1280 		dev_err(dev, "MSI or MSI-X is required for doorbell\n");
1281 		return -EINVAL;
1282 	}
1283 
1284 	func_no = ntb_epc->func_no;
1285 
1286 	db_count = ntb->db_count;
1287 	if (db_count > MAX_DB_COUNT) {
1288 		dev_err(dev, "DB count cannot be more than %d\n", MAX_DB_COUNT);
1289 		return -EINVAL;
1290 	}
1291 
1292 	ntb->db_count = db_count;
1293 	epc = ntb_epc->epc;
1294 
1295 	if (msi_capable) {
1296 		ret = pci_epc_set_msi(epc, func_no, db_count);
1297 		if (ret) {
1298 			dev_err(dev, "%s intf: MSI configuration failed\n",
1299 				pci_epc_interface_string(type));
1300 			return ret;
1301 		}
1302 	}
1303 
1304 	if (msix_capable) {
1305 		ret = pci_epc_set_msix(epc, func_no, db_count,
1306 				       ntb_epc->msix_bar,
1307 				       ntb_epc->msix_table_offset);
1308 		if (ret) {
1309 			dev_err(dev, "MSI configuration failed\n");
1310 			return ret;
1311 		}
1312 	}
1313 
1314 	return 0;
1315 }
1316 
1317 /**
1318  * epf_ntb_alloc_peer_mem() - Allocate memory in peer's outbound address space
1319  * @dev: The PCI device.
1320  * @ntb_epc: EPC associated with one of the HOST whose BAR holds peer's outbound
1321  *   address
1322  * @bar: BAR of @ntb_epc in for which memory has to be allocated (could be
1323  *   BAR_DB_MW1, BAR_MW2, BAR_MW3, BAR_MW4)
1324  * @peer_ntb_epc: EPC associated with HOST whose outbound address space is
1325  *   used by @ntb_epc
1326  * @size: Size of the address region that has to be allocated in peers OB SPACE
1327  *
1328  *
1329  * +-----------------+    +---->+----------------+-----------+-----------------+
1330  * |       BAR0      |    |     |   Doorbell 1   +-----------> MSI|X ADDRESS 1 |
1331  * +-----------------+    |     +----------------+           +-----------------+
1332  * |       BAR1      |    |     |   Doorbell 2   +---------+ |                 |
1333  * +-----------------+----+     +----------------+         | |                 |
1334  * |       BAR2      |          |   Doorbell 3   +-------+ | +-----------------+
1335  * +-----------------+----+     +----------------+       | +-> MSI|X ADDRESS 2 |
1336  * |       BAR3      |    |     |   Doorbell 4   +-----+ |   +-----------------+
1337  * +-----------------+    |     |----------------+     | |   |                 |
1338  * |       BAR4      |    |     |                |     | |   +-----------------+
1339  * +-----------------+    |     |      MW1       +---+ | +-->+ MSI|X ADDRESS 3||
1340  * |       BAR5      |    |     |                |   | |     +-----------------+
1341  * +-----------------+    +---->-----------------+   | |     |                 |
1342  *   EP CONTROLLER 1            |                |   | |     +-----------------+
1343  *                              |                |   | +---->+ MSI|X ADDRESS 4 |
1344  *                              +----------------+   |       +-----------------+
1345  *                      (A)      EP CONTROLLER 2     |       |                 |
1346  *                                 (OB SPACE)        |       |                 |
1347  *                                                   +------->      MW1        |
1348  *                                                           |                 |
1349  *                                                           |                 |
1350  *                                                   (B)     +-----------------+
1351  *                                                           |                 |
1352  *                                                           |                 |
1353  *                                                           |                 |
1354  *                                                           |                 |
1355  *                                                           |                 |
1356  *                                                           +-----------------+
1357  *                                                           PCI Address Space
1358  *                                                           (Managed by HOST2)
1359  *
1360  * Allocate memory in OB space of EP CONTROLLER 2 in the above diagram. Allocate
1361  * for Doorbell 1, Doorbell 2, Doorbell 3, Doorbell 4, MW1 (and MW2, MW3, MW4).
1362  */
1363 static int epf_ntb_alloc_peer_mem(struct device *dev,
1364 				  struct epf_ntb_epc *ntb_epc,
1365 				  enum epf_ntb_bar bar,
1366 				  struct epf_ntb_epc *peer_ntb_epc,
1367 				  size_t size)
1368 {
1369 	const struct pci_epc_features *epc_features;
1370 	struct pci_epf_bar *epf_bar;
1371 	struct pci_epc *peer_epc;
1372 	phys_addr_t phys_addr;
1373 	void __iomem *mw_addr;
1374 	enum pci_barno barno;
1375 	size_t align;
1376 
1377 	epc_features = ntb_epc->epc_features;
1378 	align = epc_features->align;
1379 
1380 	if (size < 128)
1381 		size = 128;
1382 
1383 	if (align)
1384 		size = ALIGN(size, align);
1385 	else
1386 		size = roundup_pow_of_two(size);
1387 
1388 	peer_epc = peer_ntb_epc->epc;
1389 	mw_addr = pci_epc_mem_alloc_addr(peer_epc, &phys_addr, size);
1390 	if (!mw_addr) {
1391 		dev_err(dev, "%s intf: Failed to allocate OB address\n",
1392 			pci_epc_interface_string(peer_ntb_epc->type));
1393 		return -ENOMEM;
1394 	}
1395 
1396 	barno = ntb_epc->epf_ntb_bar[bar];
1397 	epf_bar = &ntb_epc->epf_bar[barno];
1398 	ntb_epc->mw_addr[barno] = mw_addr;
1399 
1400 	epf_bar->phys_addr = phys_addr;
1401 	epf_bar->size = size;
1402 	epf_bar->barno = barno;
1403 	epf_bar->flags = PCI_BASE_ADDRESS_MEM_TYPE_32;
1404 
1405 	return 0;
1406 }
1407 
1408 /**
1409  * epf_ntb_db_mw_bar_init() - Configure Doorbell and Memory window BARs
1410  * @ntb: NTB device that facilitates communication between HOST1 and HOST2
1411  * @type: PRIMARY interface or SECONDARY interface
1412  *
1413  * Wrapper for epf_ntb_alloc_peer_mem() and pci_epc_set_bar() that allocates
1414  * memory in OB address space of HOST2 and configures BAR of HOST1
1415  */
1416 static int epf_ntb_db_mw_bar_init(struct epf_ntb *ntb,
1417 				  enum pci_epc_interface_type type)
1418 {
1419 	const struct pci_epc_features *epc_features;
1420 	struct epf_ntb_epc *peer_ntb_epc, *ntb_epc;
1421 	struct pci_epf_bar *epf_bar;
1422 	struct epf_ntb_ctrl *ctrl;
1423 	u32 num_mws, db_count;
1424 	enum epf_ntb_bar bar;
1425 	enum pci_barno barno;
1426 	struct pci_epc *epc;
1427 	struct device *dev;
1428 	size_t align;
1429 	int ret, i;
1430 	u8 func_no;
1431 	u64 size;
1432 
1433 	ntb_epc = ntb->epc[type];
1434 	peer_ntb_epc = ntb->epc[!type];
1435 
1436 	dev = &ntb->epf->dev;
1437 	epc_features = ntb_epc->epc_features;
1438 	align = epc_features->align;
1439 	func_no = ntb_epc->func_no;
1440 	epc = ntb_epc->epc;
1441 	num_mws = ntb->num_mws;
1442 	db_count = ntb->db_count;
1443 
1444 	for (bar = BAR_DB_MW1, i = 0; i < num_mws; bar++, i++) {
1445 		if (bar == BAR_DB_MW1) {
1446 			align = align ? align : 4;
1447 			size = db_count * align;
1448 			size = ALIGN(size, ntb->mws_size[i]);
1449 			ctrl = ntb_epc->reg;
1450 			ctrl->mw1_offset = size;
1451 			size += ntb->mws_size[i];
1452 		} else {
1453 			size = ntb->mws_size[i];
1454 		}
1455 
1456 		ret = epf_ntb_alloc_peer_mem(dev, ntb_epc, bar,
1457 					     peer_ntb_epc, size);
1458 		if (ret) {
1459 			dev_err(dev, "%s intf: DoorBell mem alloc failed\n",
1460 				pci_epc_interface_string(type));
1461 			goto err_alloc_peer_mem;
1462 		}
1463 
1464 		barno = ntb_epc->epf_ntb_bar[bar];
1465 		epf_bar = &ntb_epc->epf_bar[barno];
1466 
1467 		ret = pci_epc_set_bar(epc, func_no, epf_bar);
1468 		if (ret) {
1469 			dev_err(dev, "%s intf: DoorBell BAR set failed\n",
1470 				pci_epc_interface_string(type));
1471 			goto err_alloc_peer_mem;
1472 		}
1473 	}
1474 
1475 	return 0;
1476 
1477 err_alloc_peer_mem:
1478 	epf_ntb_db_mw_bar_cleanup(ntb, type);
1479 
1480 	return ret;
1481 }
1482 
1483 /**
1484  * epf_ntb_epc_destroy_interface() - Cleanup NTB EPC interface
1485  * @ntb: NTB device that facilitates communication between HOST1 and HOST2
1486  * @type: PRIMARY interface or SECONDARY interface
1487  *
1488  * Unbind NTB function device from EPC and relinquish reference to pci_epc
1489  * for each of the interface.
1490  */
1491 static void epf_ntb_epc_destroy_interface(struct epf_ntb *ntb,
1492 					  enum pci_epc_interface_type type)
1493 {
1494 	struct epf_ntb_epc *ntb_epc;
1495 	struct pci_epc *epc;
1496 	struct pci_epf *epf;
1497 
1498 	if (type < 0)
1499 		return;
1500 
1501 	epf = ntb->epf;
1502 	ntb_epc = ntb->epc[type];
1503 	if (!ntb_epc)
1504 		return;
1505 	epc = ntb_epc->epc;
1506 	pci_epc_remove_epf(epc, epf, type);
1507 	pci_epc_put(epc);
1508 }
1509 
1510 /**
1511  * epf_ntb_epc_destroy() - Cleanup NTB EPC interface
1512  * @ntb: NTB device that facilitates communication between HOST1 and HOST2
1513  *
1514  * Wrapper for epf_ntb_epc_destroy_interface() to cleanup all the NTB interfaces
1515  */
1516 static void epf_ntb_epc_destroy(struct epf_ntb *ntb)
1517 {
1518 	enum pci_epc_interface_type type;
1519 
1520 	for (type = PRIMARY_INTERFACE; type <= SECONDARY_INTERFACE; type++)
1521 		epf_ntb_epc_destroy_interface(ntb, type);
1522 }
1523 
1524 /**
1525  * epf_ntb_epc_create_interface() - Create and initialize NTB EPC interface
1526  * @ntb: NTB device that facilitates communication between HOST1 and HOST2
1527  * @epc: struct pci_epc to which a particular NTB interface should be associated
1528  * @type: PRIMARY interface or SECONDARY interface
1529  *
1530  * Allocate memory for NTB EPC interface and initialize it.
1531  */
1532 static int epf_ntb_epc_create_interface(struct epf_ntb *ntb,
1533 					struct pci_epc *epc,
1534 					enum pci_epc_interface_type type)
1535 {
1536 	const struct pci_epc_features *epc_features;
1537 	struct pci_epf_bar *epf_bar;
1538 	struct epf_ntb_epc *ntb_epc;
1539 	struct pci_epf *epf;
1540 	struct device *dev;
1541 	u8 func_no;
1542 
1543 	dev = &ntb->epf->dev;
1544 
1545 	ntb_epc = devm_kzalloc(dev, sizeof(*ntb_epc), GFP_KERNEL);
1546 	if (!ntb_epc)
1547 		return -ENOMEM;
1548 
1549 	epf = ntb->epf;
1550 	if (type == PRIMARY_INTERFACE) {
1551 		func_no = epf->func_no;
1552 		epf_bar = epf->bar;
1553 	} else {
1554 		func_no = epf->sec_epc_func_no;
1555 		epf_bar = epf->sec_epc_bar;
1556 	}
1557 
1558 	ntb_epc->linkup = false;
1559 	ntb_epc->epc = epc;
1560 	ntb_epc->func_no = func_no;
1561 	ntb_epc->type = type;
1562 	ntb_epc->epf_bar = epf_bar;
1563 	ntb_epc->epf_ntb = ntb;
1564 
1565 	epc_features = pci_epc_get_features(epc, func_no);
1566 	if (!epc_features)
1567 		return -EINVAL;
1568 	ntb_epc->epc_features = epc_features;
1569 
1570 	ntb->epc[type] = ntb_epc;
1571 
1572 	return 0;
1573 }
1574 
1575 /**
1576  * epf_ntb_epc_create() - Create and initialize NTB EPC interface
1577  * @ntb: NTB device that facilitates communication between HOST1 and HOST2
1578  *
1579  * Get a reference to EPC device and bind NTB function device to that EPC
1580  * for each of the interface. It is also a wrapper to
1581  * epf_ntb_epc_create_interface() to allocate memory for NTB EPC interface
1582  * and initialize it
1583  */
1584 static int epf_ntb_epc_create(struct epf_ntb *ntb)
1585 {
1586 	struct pci_epf *epf;
1587 	struct device *dev;
1588 	int ret;
1589 
1590 	epf = ntb->epf;
1591 	dev = &epf->dev;
1592 
1593 	ret = epf_ntb_epc_create_interface(ntb, epf->epc, PRIMARY_INTERFACE);
1594 	if (ret) {
1595 		dev_err(dev, "PRIMARY intf: Fail to create NTB EPC\n");
1596 		return ret;
1597 	}
1598 
1599 	ret = epf_ntb_epc_create_interface(ntb, epf->sec_epc,
1600 					   SECONDARY_INTERFACE);
1601 	if (ret) {
1602 		dev_err(dev, "SECONDARY intf: Fail to create NTB EPC\n");
1603 		goto err_epc_create;
1604 	}
1605 
1606 	return 0;
1607 
1608 err_epc_create:
1609 	epf_ntb_epc_destroy_interface(ntb, PRIMARY_INTERFACE);
1610 
1611 	return ret;
1612 }
1613 
1614 /**
1615  * epf_ntb_init_epc_bar_interface() - Identify BARs to be used for each of
1616  *   the NTB constructs (scratchpad region, doorbell, memorywindow)
1617  * @ntb: NTB device that facilitates communication between HOST1 and HOST2
1618  * @type: PRIMARY interface or SECONDARY interface
1619  *
1620  * Identify the free BARs to be used for each of BAR_CONFIG, BAR_PEER_SPAD,
1621  * BAR_DB_MW1, BAR_MW2, BAR_MW3 and BAR_MW4.
1622  */
1623 static int epf_ntb_init_epc_bar_interface(struct epf_ntb *ntb,
1624 					  enum pci_epc_interface_type type)
1625 {
1626 	const struct pci_epc_features *epc_features;
1627 	struct epf_ntb_epc *ntb_epc;
1628 	enum pci_barno barno;
1629 	enum epf_ntb_bar bar;
1630 	struct device *dev;
1631 	u32 num_mws;
1632 	int i;
1633 
1634 	barno = BAR_0;
1635 	ntb_epc = ntb->epc[type];
1636 	num_mws = ntb->num_mws;
1637 	dev = &ntb->epf->dev;
1638 	epc_features = ntb_epc->epc_features;
1639 
1640 	/* These are required BARs which are mandatory for NTB functionality */
1641 	for (bar = BAR_CONFIG; bar <= BAR_DB_MW1; bar++, barno++) {
1642 		barno = pci_epc_get_next_free_bar(epc_features, barno);
1643 		if (barno < 0) {
1644 			dev_err(dev, "%s intf: Fail to get NTB function BAR\n",
1645 				pci_epc_interface_string(type));
1646 			return barno;
1647 		}
1648 		ntb_epc->epf_ntb_bar[bar] = barno;
1649 	}
1650 
1651 	/* These are optional BARs which don't impact NTB functionality */
1652 	for (bar = BAR_MW2, i = 1; i < num_mws; bar++, barno++, i++) {
1653 		barno = pci_epc_get_next_free_bar(epc_features, barno);
1654 		if (barno < 0) {
1655 			ntb->num_mws = i;
1656 			dev_dbg(dev, "BAR not available for > MW%d\n", i + 1);
1657 		}
1658 		ntb_epc->epf_ntb_bar[bar] = barno;
1659 	}
1660 
1661 	return 0;
1662 }
1663 
1664 /**
1665  * epf_ntb_init_epc_bar() - Identify BARs to be used for each of the NTB
1666  * constructs (scratchpad region, doorbell, memorywindow)
1667  * @ntb: NTB device that facilitates communication between HOST1 and HOST2
1668  *
1669  * Wrapper to epf_ntb_init_epc_bar_interface() to identify the free BARs
1670  * to be used for each of BAR_CONFIG, BAR_PEER_SPAD, BAR_DB_MW1, BAR_MW2,
1671  * BAR_MW3 and BAR_MW4 for all the interfaces.
1672  */
1673 static int epf_ntb_init_epc_bar(struct epf_ntb *ntb)
1674 {
1675 	enum pci_epc_interface_type type;
1676 	struct device *dev;
1677 	int ret;
1678 
1679 	dev = &ntb->epf->dev;
1680 	for (type = PRIMARY_INTERFACE; type <= SECONDARY_INTERFACE; type++) {
1681 		ret = epf_ntb_init_epc_bar_interface(ntb, type);
1682 		if (ret) {
1683 			dev_err(dev, "Fail to init EPC bar for %s interface\n",
1684 				pci_epc_interface_string(type));
1685 			return ret;
1686 		}
1687 	}
1688 
1689 	return 0;
1690 }
1691 
1692 /**
1693  * epf_ntb_epc_init_interface() - Initialize NTB interface
1694  * @ntb: NTB device that facilitates communication between HOST1 and HOST2
1695  * @type: PRIMARY interface or SECONDARY interface
1696  *
1697  * Wrapper to initialize a particular EPC interface and start the workqueue
1698  * to check for commands from host. This function will write to the
1699  * EP controller HW for configuring it.
1700  */
1701 static int epf_ntb_epc_init_interface(struct epf_ntb *ntb,
1702 				      enum pci_epc_interface_type type)
1703 {
1704 	struct epf_ntb_epc *ntb_epc;
1705 	struct pci_epc *epc;
1706 	struct pci_epf *epf;
1707 	struct device *dev;
1708 	u8 func_no;
1709 	int ret;
1710 
1711 	ntb_epc = ntb->epc[type];
1712 	epf = ntb->epf;
1713 	dev = &epf->dev;
1714 	epc = ntb_epc->epc;
1715 	func_no = ntb_epc->func_no;
1716 
1717 	ret = epf_ntb_config_sspad_bar_set(ntb->epc[type]);
1718 	if (ret) {
1719 		dev_err(dev, "%s intf: Config/self SPAD BAR init failed\n",
1720 			pci_epc_interface_string(type));
1721 		return ret;
1722 	}
1723 
1724 	ret = epf_ntb_peer_spad_bar_set(ntb, type);
1725 	if (ret) {
1726 		dev_err(dev, "%s intf: Peer SPAD BAR init failed\n",
1727 			pci_epc_interface_string(type));
1728 		goto err_peer_spad_bar_init;
1729 	}
1730 
1731 	ret = epf_ntb_configure_interrupt(ntb, type);
1732 	if (ret) {
1733 		dev_err(dev, "%s intf: Interrupt configuration failed\n",
1734 			pci_epc_interface_string(type));
1735 		goto err_peer_spad_bar_init;
1736 	}
1737 
1738 	ret = epf_ntb_db_mw_bar_init(ntb, type);
1739 	if (ret) {
1740 		dev_err(dev, "%s intf: DB/MW BAR init failed\n",
1741 			pci_epc_interface_string(type));
1742 		goto err_db_mw_bar_init;
1743 	}
1744 
1745 	ret = pci_epc_write_header(epc, func_no, epf->header);
1746 	if (ret) {
1747 		dev_err(dev, "%s intf: Configuration header write failed\n",
1748 			pci_epc_interface_string(type));
1749 		goto err_write_header;
1750 	}
1751 
1752 	INIT_DELAYED_WORK(&ntb->epc[type]->cmd_handler, epf_ntb_cmd_handler);
1753 	queue_work(kpcintb_workqueue, &ntb->epc[type]->cmd_handler.work);
1754 
1755 	return 0;
1756 
1757 err_write_header:
1758 	epf_ntb_db_mw_bar_cleanup(ntb, type);
1759 
1760 err_db_mw_bar_init:
1761 	epf_ntb_peer_spad_bar_clear(ntb->epc[type]);
1762 
1763 err_peer_spad_bar_init:
1764 	epf_ntb_config_sspad_bar_clear(ntb->epc[type]);
1765 
1766 	return ret;
1767 }
1768 
1769 /**
1770  * epf_ntb_epc_cleanup_interface() - Cleanup NTB interface
1771  * @ntb: NTB device that facilitates communication between HOST1 and HOST2
1772  * @type: PRIMARY interface or SECONDARY interface
1773  *
1774  * Wrapper to cleanup a particular NTB interface.
1775  */
1776 static void epf_ntb_epc_cleanup_interface(struct epf_ntb *ntb,
1777 					  enum pci_epc_interface_type type)
1778 {
1779 	struct epf_ntb_epc *ntb_epc;
1780 
1781 	if (type < 0)
1782 		return;
1783 
1784 	ntb_epc = ntb->epc[type];
1785 	cancel_delayed_work(&ntb_epc->cmd_handler);
1786 	epf_ntb_db_mw_bar_cleanup(ntb, type);
1787 	epf_ntb_peer_spad_bar_clear(ntb_epc);
1788 	epf_ntb_config_sspad_bar_clear(ntb_epc);
1789 }
1790 
1791 /**
1792  * epf_ntb_epc_cleanup() - Cleanup all NTB interfaces
1793  * @ntb: NTB device that facilitates communication between HOST1 and HOST2
1794  *
1795  * Wrapper to cleanup all NTB interfaces.
1796  */
1797 static void epf_ntb_epc_cleanup(struct epf_ntb *ntb)
1798 {
1799 	enum pci_epc_interface_type type;
1800 
1801 	for (type = PRIMARY_INTERFACE; type <= SECONDARY_INTERFACE; type++)
1802 		epf_ntb_epc_cleanup_interface(ntb, type);
1803 }
1804 
1805 /**
1806  * epf_ntb_epc_init() - Initialize all NTB interfaces
1807  * @ntb: NTB device that facilitates communication between HOST1 and HOST2
1808  *
1809  * Wrapper to initialize all NTB interface and start the workqueue
1810  * to check for commands from host.
1811  */
1812 static int epf_ntb_epc_init(struct epf_ntb *ntb)
1813 {
1814 	enum pci_epc_interface_type type;
1815 	struct device *dev;
1816 	int ret;
1817 
1818 	dev = &ntb->epf->dev;
1819 
1820 	for (type = PRIMARY_INTERFACE; type <= SECONDARY_INTERFACE; type++) {
1821 		ret = epf_ntb_epc_init_interface(ntb, type);
1822 		if (ret) {
1823 			dev_err(dev, "%s intf: Failed to initialize\n",
1824 				pci_epc_interface_string(type));
1825 			goto err_init_type;
1826 		}
1827 	}
1828 
1829 	return 0;
1830 
1831 err_init_type:
1832 	epf_ntb_epc_cleanup_interface(ntb, type - 1);
1833 
1834 	return ret;
1835 }
1836 
1837 /**
1838  * epf_ntb_bind() - Initialize endpoint controller to provide NTB functionality
1839  * @epf: NTB endpoint function device
1840  *
1841  * Initialize both the endpoint controllers associated with NTB function device.
1842  * Invoked when a primary interface or secondary interface is bound to EPC
1843  * device. This function will succeed only when EPC is bound to both the
1844  * interfaces.
1845  */
1846 static int epf_ntb_bind(struct pci_epf *epf)
1847 {
1848 	struct epf_ntb *ntb = epf_get_drvdata(epf);
1849 	struct device *dev = &epf->dev;
1850 	int ret;
1851 
1852 	if (!epf->epc) {
1853 		dev_dbg(dev, "PRIMARY EPC interface not yet bound\n");
1854 		return 0;
1855 	}
1856 
1857 	if (!epf->sec_epc) {
1858 		dev_dbg(dev, "SECONDARY EPC interface not yet bound\n");
1859 		return 0;
1860 	}
1861 
1862 	ret = epf_ntb_epc_create(ntb);
1863 	if (ret) {
1864 		dev_err(dev, "Failed to create NTB EPC\n");
1865 		return ret;
1866 	}
1867 
1868 	ret = epf_ntb_init_epc_bar(ntb);
1869 	if (ret) {
1870 		dev_err(dev, "Failed to create NTB EPC\n");
1871 		goto err_bar_init;
1872 	}
1873 
1874 	ret = epf_ntb_config_spad_bar_alloc_interface(ntb);
1875 	if (ret) {
1876 		dev_err(dev, "Failed to allocate BAR memory\n");
1877 		goto err_bar_alloc;
1878 	}
1879 
1880 	ret = epf_ntb_epc_init(ntb);
1881 	if (ret) {
1882 		dev_err(dev, "Failed to initialize EPC\n");
1883 		goto err_bar_alloc;
1884 	}
1885 
1886 	epf_set_drvdata(epf, ntb);
1887 
1888 	return 0;
1889 
1890 err_bar_alloc:
1891 	epf_ntb_config_spad_bar_free(ntb);
1892 
1893 err_bar_init:
1894 	epf_ntb_epc_destroy(ntb);
1895 
1896 	return ret;
1897 }
1898 
1899 /**
1900  * epf_ntb_unbind() - Cleanup the initialization from epf_ntb_bind()
1901  * @epf: NTB endpoint function device
1902  *
1903  * Cleanup the initialization from epf_ntb_bind()
1904  */
1905 static void epf_ntb_unbind(struct pci_epf *epf)
1906 {
1907 	struct epf_ntb *ntb = epf_get_drvdata(epf);
1908 
1909 	epf_ntb_epc_cleanup(ntb);
1910 	epf_ntb_config_spad_bar_free(ntb);
1911 	epf_ntb_epc_destroy(ntb);
1912 }
1913 
1914 #define EPF_NTB_R(_name)						\
1915 static ssize_t epf_ntb_##_name##_show(struct config_item *item,		\
1916 				      char *page)			\
1917 {									\
1918 	struct config_group *group = to_config_group(item);		\
1919 	struct epf_ntb *ntb = to_epf_ntb(group);			\
1920 									\
1921 	return sprintf(page, "%d\n", ntb->_name);			\
1922 }
1923 
1924 #define EPF_NTB_W(_name)						\
1925 static ssize_t epf_ntb_##_name##_store(struct config_item *item,	\
1926 				       const char *page, size_t len)	\
1927 {									\
1928 	struct config_group *group = to_config_group(item);		\
1929 	struct epf_ntb *ntb = to_epf_ntb(group);			\
1930 	u32 val;							\
1931 	int ret;							\
1932 									\
1933 	ret = kstrtou32(page, 0, &val);					\
1934 	if (ret)							\
1935 		return ret;						\
1936 									\
1937 	ntb->_name = val;						\
1938 									\
1939 	return len;							\
1940 }
1941 
1942 #define EPF_NTB_MW_R(_name)						\
1943 static ssize_t epf_ntb_##_name##_show(struct config_item *item,		\
1944 				      char *page)			\
1945 {									\
1946 	struct config_group *group = to_config_group(item);		\
1947 	struct epf_ntb *ntb = to_epf_ntb(group);			\
1948 	int win_no;							\
1949 									\
1950 	sscanf(#_name, "mw%d", &win_no);				\
1951 									\
1952 	return sprintf(page, "%lld\n", ntb->mws_size[win_no - 1]);	\
1953 }
1954 
1955 #define EPF_NTB_MW_W(_name)						\
1956 static ssize_t epf_ntb_##_name##_store(struct config_item *item,	\
1957 				       const char *page, size_t len)	\
1958 {									\
1959 	struct config_group *group = to_config_group(item);		\
1960 	struct epf_ntb *ntb = to_epf_ntb(group);			\
1961 	struct device *dev = &ntb->epf->dev;				\
1962 	int win_no;							\
1963 	u64 val;							\
1964 	int ret;							\
1965 									\
1966 	ret = kstrtou64(page, 0, &val);					\
1967 	if (ret)							\
1968 		return ret;						\
1969 									\
1970 	if (sscanf(#_name, "mw%d", &win_no) != 1)			\
1971 		return -EINVAL;						\
1972 									\
1973 	if (ntb->num_mws < win_no) {					\
1974 		dev_err(dev, "Invalid num_nws: %d value\n", ntb->num_mws); \
1975 		return -EINVAL;						\
1976 	}								\
1977 									\
1978 	ntb->mws_size[win_no - 1] = val;				\
1979 									\
1980 	return len;							\
1981 }
1982 
1983 static ssize_t epf_ntb_num_mws_store(struct config_item *item,
1984 				     const char *page, size_t len)
1985 {
1986 	struct config_group *group = to_config_group(item);
1987 	struct epf_ntb *ntb = to_epf_ntb(group);
1988 	u32 val;
1989 	int ret;
1990 
1991 	ret = kstrtou32(page, 0, &val);
1992 	if (ret)
1993 		return ret;
1994 
1995 	if (val > MAX_MW)
1996 		return -EINVAL;
1997 
1998 	ntb->num_mws = val;
1999 
2000 	return len;
2001 }
2002 
2003 EPF_NTB_R(spad_count)
2004 EPF_NTB_W(spad_count)
2005 EPF_NTB_R(db_count)
2006 EPF_NTB_W(db_count)
2007 EPF_NTB_R(num_mws)
2008 EPF_NTB_MW_R(mw1)
2009 EPF_NTB_MW_W(mw1)
2010 EPF_NTB_MW_R(mw2)
2011 EPF_NTB_MW_W(mw2)
2012 EPF_NTB_MW_R(mw3)
2013 EPF_NTB_MW_W(mw3)
2014 EPF_NTB_MW_R(mw4)
2015 EPF_NTB_MW_W(mw4)
2016 
2017 CONFIGFS_ATTR(epf_ntb_, spad_count);
2018 CONFIGFS_ATTR(epf_ntb_, db_count);
2019 CONFIGFS_ATTR(epf_ntb_, num_mws);
2020 CONFIGFS_ATTR(epf_ntb_, mw1);
2021 CONFIGFS_ATTR(epf_ntb_, mw2);
2022 CONFIGFS_ATTR(epf_ntb_, mw3);
2023 CONFIGFS_ATTR(epf_ntb_, mw4);
2024 
2025 static struct configfs_attribute *epf_ntb_attrs[] = {
2026 	&epf_ntb_attr_spad_count,
2027 	&epf_ntb_attr_db_count,
2028 	&epf_ntb_attr_num_mws,
2029 	&epf_ntb_attr_mw1,
2030 	&epf_ntb_attr_mw2,
2031 	&epf_ntb_attr_mw3,
2032 	&epf_ntb_attr_mw4,
2033 	NULL,
2034 };
2035 
2036 static const struct config_item_type ntb_group_type = {
2037 	.ct_attrs	= epf_ntb_attrs,
2038 	.ct_owner	= THIS_MODULE,
2039 };
2040 
2041 /**
2042  * epf_ntb_add_cfs() - Add configfs directory specific to NTB
2043  * @epf: NTB endpoint function device
2044  * @group: A pointer to the config_group structure referencing a group of
2045  *	   config_items of a specific type that belong to a specific sub-system.
2046  *
2047  * Add configfs directory specific to NTB. This directory will hold
2048  * NTB specific properties like db_count, spad_count, num_mws etc.,
2049  */
2050 static struct config_group *epf_ntb_add_cfs(struct pci_epf *epf,
2051 					    struct config_group *group)
2052 {
2053 	struct epf_ntb *ntb = epf_get_drvdata(epf);
2054 	struct config_group *ntb_group = &ntb->group;
2055 	struct device *dev = &epf->dev;
2056 
2057 	config_group_init_type_name(ntb_group, dev_name(dev), &ntb_group_type);
2058 
2059 	return ntb_group;
2060 }
2061 
2062 /**
2063  * epf_ntb_probe() - Probe NTB function driver
2064  * @epf: NTB endpoint function device
2065  *
2066  * Probe NTB function driver when endpoint function bus detects a NTB
2067  * endpoint function.
2068  */
2069 static int epf_ntb_probe(struct pci_epf *epf)
2070 {
2071 	struct epf_ntb *ntb;
2072 	struct device *dev;
2073 
2074 	dev = &epf->dev;
2075 
2076 	ntb = devm_kzalloc(dev, sizeof(*ntb), GFP_KERNEL);
2077 	if (!ntb)
2078 		return -ENOMEM;
2079 
2080 	epf->header = &epf_ntb_header;
2081 	ntb->epf = epf;
2082 	epf_set_drvdata(epf, ntb);
2083 
2084 	return 0;
2085 }
2086 
2087 static struct pci_epf_ops epf_ntb_ops = {
2088 	.bind	= epf_ntb_bind,
2089 	.unbind	= epf_ntb_unbind,
2090 	.add_cfs = epf_ntb_add_cfs,
2091 };
2092 
2093 static const struct pci_epf_device_id epf_ntb_ids[] = {
2094 	{
2095 		.name = "pci_epf_ntb",
2096 	},
2097 	{},
2098 };
2099 
2100 static struct pci_epf_driver epf_ntb_driver = {
2101 	.driver.name	= "pci_epf_ntb",
2102 	.probe		= epf_ntb_probe,
2103 	.id_table	= epf_ntb_ids,
2104 	.ops		= &epf_ntb_ops,
2105 	.owner		= THIS_MODULE,
2106 };
2107 
2108 static int __init epf_ntb_init(void)
2109 {
2110 	int ret;
2111 
2112 	kpcintb_workqueue = alloc_workqueue("kpcintb", WQ_MEM_RECLAIM |
2113 					    WQ_HIGHPRI, 0);
2114 	ret = pci_epf_register_driver(&epf_ntb_driver);
2115 	if (ret) {
2116 		destroy_workqueue(kpcintb_workqueue);
2117 		pr_err("Failed to register pci epf ntb driver --> %d\n", ret);
2118 		return ret;
2119 	}
2120 
2121 	return 0;
2122 }
2123 module_init(epf_ntb_init);
2124 
2125 static void __exit epf_ntb_exit(void)
2126 {
2127 	pci_epf_unregister_driver(&epf_ntb_driver);
2128 	destroy_workqueue(kpcintb_workqueue);
2129 }
2130 module_exit(epf_ntb_exit);
2131 
2132 MODULE_DESCRIPTION("PCI EPF NTB DRIVER");
2133 MODULE_AUTHOR("Kishon Vijay Abraham I <kishon@ti.com>");
2134 MODULE_LICENSE("GPL v2");
2135