xref: /openbmc/linux/drivers/platform/x86/intel/vsec.c (revision 461ba3e7)
1 // SPDX-License-Identifier: GPL-2.0
2 /*
3  * Intel Vendor Specific Extended Capabilities auxiliary bus driver
4  *
5  * Copyright (c) 2021, Intel Corporation.
6  * All Rights Reserved.
7  *
8  * Author: David E. Box <david.e.box@linux.intel.com>
9  *
10  * This driver discovers and creates auxiliary devices for Intel defined PCIe
11  * "Vendor Specific" and "Designated Vendor Specific" Extended Capabilities,
12  * VSEC and DVSEC respectively. The driver supports features on specific PCIe
13  * endpoints that exist primarily to expose them.
14  */
15 
16 #include <linux/auxiliary_bus.h>
17 #include <linux/bits.h>
18 #include <linux/delay.h>
19 #include <linux/kernel.h>
20 #include <linux/idr.h>
21 #include <linux/module.h>
22 #include <linux/pci.h>
23 #include <linux/types.h>
24 
25 #include "vsec.h"
26 
27 /* Intel DVSEC offsets */
28 #define INTEL_DVSEC_ENTRIES		0xA
29 #define INTEL_DVSEC_SIZE		0xB
30 #define INTEL_DVSEC_TABLE		0xC
31 #define INTEL_DVSEC_TABLE_BAR(x)	((x) & GENMASK(2, 0))
32 #define INTEL_DVSEC_TABLE_OFFSET(x)	((x) & GENMASK(31, 3))
33 #define TABLE_OFFSET_SHIFT		3
34 #define PMT_XA_START			0
35 #define PMT_XA_MAX			INT_MAX
36 #define PMT_XA_LIMIT			XA_LIMIT(PMT_XA_START, PMT_XA_MAX)
37 
38 static DEFINE_IDA(intel_vsec_ida);
39 static DEFINE_IDA(intel_vsec_sdsi_ida);
40 static DEFINE_XARRAY_ALLOC(auxdev_array);
41 
42 /**
43  * struct intel_vsec_header - Common fields of Intel VSEC and DVSEC registers.
44  * @rev:         Revision ID of the VSEC/DVSEC register space
45  * @length:      Length of the VSEC/DVSEC register space
46  * @id:          ID of the feature
47  * @num_entries: Number of instances of the feature
48  * @entry_size:  Size of the discovery table for each feature
49  * @tbir:        BAR containing the discovery tables
50  * @offset:      BAR offset of start of the first discovery table
51  */
52 struct intel_vsec_header {
53 	u8	rev;
54 	u16	length;
55 	u16	id;
56 	u8	num_entries;
57 	u8	entry_size;
58 	u8	tbir;
59 	u32	offset;
60 };
61 
62 enum intel_vsec_id {
63 	VSEC_ID_TELEMETRY	= 2,
64 	VSEC_ID_WATCHER		= 3,
65 	VSEC_ID_CRASHLOG	= 4,
66 	VSEC_ID_SDSI		= 65,
67 	VSEC_ID_TPMI		= 66,
68 };
69 
70 static enum intel_vsec_id intel_vsec_allow_list[] = {
71 	VSEC_ID_TELEMETRY,
72 	VSEC_ID_WATCHER,
73 	VSEC_ID_CRASHLOG,
74 	VSEC_ID_SDSI,
75 	VSEC_ID_TPMI,
76 };
77 
78 static const char *intel_vsec_name(enum intel_vsec_id id)
79 {
80 	switch (id) {
81 	case VSEC_ID_TELEMETRY:
82 		return "telemetry";
83 
84 	case VSEC_ID_WATCHER:
85 		return "watcher";
86 
87 	case VSEC_ID_CRASHLOG:
88 		return "crashlog";
89 
90 	case VSEC_ID_SDSI:
91 		return "sdsi";
92 
93 	case VSEC_ID_TPMI:
94 		return "tpmi";
95 
96 	default:
97 		return NULL;
98 	}
99 }
100 
101 static bool intel_vsec_allowed(u16 id)
102 {
103 	int i;
104 
105 	for (i = 0; i < ARRAY_SIZE(intel_vsec_allow_list); i++)
106 		if (intel_vsec_allow_list[i] == id)
107 			return true;
108 
109 	return false;
110 }
111 
112 static bool intel_vsec_disabled(u16 id, unsigned long quirks)
113 {
114 	switch (id) {
115 	case VSEC_ID_WATCHER:
116 		return !!(quirks & VSEC_QUIRK_NO_WATCHER);
117 
118 	case VSEC_ID_CRASHLOG:
119 		return !!(quirks & VSEC_QUIRK_NO_CRASHLOG);
120 
121 	default:
122 		return false;
123 	}
124 }
125 
126 static void intel_vsec_remove_aux(void *data)
127 {
128 	auxiliary_device_delete(data);
129 	auxiliary_device_uninit(data);
130 }
131 
132 static DEFINE_MUTEX(vsec_ida_lock);
133 
134 static void intel_vsec_dev_release(struct device *dev)
135 {
136 	struct intel_vsec_device *intel_vsec_dev = dev_to_ivdev(dev);
137 
138 	mutex_lock(&vsec_ida_lock);
139 	ida_free(intel_vsec_dev->ida, intel_vsec_dev->auxdev.id);
140 	mutex_unlock(&vsec_ida_lock);
141 
142 	kfree(intel_vsec_dev->resource);
143 	kfree(intel_vsec_dev);
144 }
145 
146 int intel_vsec_add_aux(struct pci_dev *pdev, struct device *parent,
147 		       struct intel_vsec_device *intel_vsec_dev,
148 		       const char *name)
149 {
150 	struct auxiliary_device *auxdev = &intel_vsec_dev->auxdev;
151 	int ret, id;
152 
153 	mutex_lock(&vsec_ida_lock);
154 	ret = ida_alloc(intel_vsec_dev->ida, GFP_KERNEL);
155 	mutex_unlock(&vsec_ida_lock);
156 	if (ret < 0) {
157 		kfree(intel_vsec_dev);
158 		return ret;
159 	}
160 
161 	if (!parent)
162 		parent = &pdev->dev;
163 
164 	auxdev->id = ret;
165 	auxdev->name = name;
166 	auxdev->dev.parent = parent;
167 	auxdev->dev.release = intel_vsec_dev_release;
168 
169 	ret = auxiliary_device_init(auxdev);
170 	if (ret < 0) {
171 		mutex_lock(&vsec_ida_lock);
172 		ida_free(intel_vsec_dev->ida, auxdev->id);
173 		mutex_unlock(&vsec_ida_lock);
174 		kfree(intel_vsec_dev->resource);
175 		kfree(intel_vsec_dev);
176 		return ret;
177 	}
178 
179 	ret = auxiliary_device_add(auxdev);
180 	if (ret < 0) {
181 		auxiliary_device_uninit(auxdev);
182 		return ret;
183 	}
184 
185 	ret = devm_add_action_or_reset(parent, intel_vsec_remove_aux,
186 				       auxdev);
187 	if (ret < 0)
188 		return ret;
189 
190 	/* Add auxdev to list */
191 	ret = xa_alloc(&auxdev_array, &id, intel_vsec_dev, PMT_XA_LIMIT,
192 		       GFP_KERNEL);
193 	if (ret)
194 		return ret;
195 
196 	return 0;
197 }
198 EXPORT_SYMBOL_NS_GPL(intel_vsec_add_aux, INTEL_VSEC);
199 
200 static int intel_vsec_add_dev(struct pci_dev *pdev, struct intel_vsec_header *header,
201 			      struct intel_vsec_platform_info *info)
202 {
203 	struct intel_vsec_device *intel_vsec_dev;
204 	struct resource *res, *tmp;
205 	unsigned long quirks = info->quirks;
206 	int i;
207 
208 	if (!intel_vsec_allowed(header->id) || intel_vsec_disabled(header->id, quirks))
209 		return -EINVAL;
210 
211 	if (!header->num_entries) {
212 		dev_dbg(&pdev->dev, "Invalid 0 entry count for header id %d\n", header->id);
213 		return -EINVAL;
214 	}
215 
216 	if (!header->entry_size) {
217 		dev_dbg(&pdev->dev, "Invalid 0 entry size for header id %d\n", header->id);
218 		return -EINVAL;
219 	}
220 
221 	intel_vsec_dev = kzalloc(sizeof(*intel_vsec_dev), GFP_KERNEL);
222 	if (!intel_vsec_dev)
223 		return -ENOMEM;
224 
225 	res = kcalloc(header->num_entries, sizeof(*res), GFP_KERNEL);
226 	if (!res) {
227 		kfree(intel_vsec_dev);
228 		return -ENOMEM;
229 	}
230 
231 	if (quirks & VSEC_QUIRK_TABLE_SHIFT)
232 		header->offset >>= TABLE_OFFSET_SHIFT;
233 
234 	/*
235 	 * The DVSEC/VSEC contains the starting offset and count for a block of
236 	 * discovery tables. Create a resource array of these tables to the
237 	 * auxiliary device driver.
238 	 */
239 	for (i = 0, tmp = res; i < header->num_entries; i++, tmp++) {
240 		tmp->start = pdev->resource[header->tbir].start +
241 			     header->offset + i * (header->entry_size * sizeof(u32));
242 		tmp->end = tmp->start + (header->entry_size * sizeof(u32)) - 1;
243 		tmp->flags = IORESOURCE_MEM;
244 	}
245 
246 	intel_vsec_dev->pcidev = pdev;
247 	intel_vsec_dev->resource = res;
248 	intel_vsec_dev->num_resources = header->num_entries;
249 	intel_vsec_dev->info = info;
250 
251 	if (header->id == VSEC_ID_SDSI)
252 		intel_vsec_dev->ida = &intel_vsec_sdsi_ida;
253 	else
254 		intel_vsec_dev->ida = &intel_vsec_ida;
255 
256 	return intel_vsec_add_aux(pdev, NULL, intel_vsec_dev,
257 				  intel_vsec_name(header->id));
258 }
259 
260 static bool intel_vsec_walk_header(struct pci_dev *pdev,
261 				   struct intel_vsec_platform_info *info)
262 {
263 	struct intel_vsec_header **header = info->capabilities;
264 	bool have_devices = false;
265 	int ret;
266 
267 	for ( ; *header; header++) {
268 		ret = intel_vsec_add_dev(pdev, *header, info);
269 		if (ret)
270 			dev_info(&pdev->dev, "Could not add device for DVSEC id %d\n",
271 				 (*header)->id);
272 		else
273 			have_devices = true;
274 	}
275 
276 	return have_devices;
277 }
278 
279 static bool intel_vsec_walk_dvsec(struct pci_dev *pdev,
280 				  struct intel_vsec_platform_info *info)
281 {
282 	bool have_devices = false;
283 	int pos = 0;
284 
285 	do {
286 		struct intel_vsec_header header;
287 		u32 table, hdr;
288 		u16 vid;
289 		int ret;
290 
291 		pos = pci_find_next_ext_capability(pdev, pos, PCI_EXT_CAP_ID_DVSEC);
292 		if (!pos)
293 			break;
294 
295 		pci_read_config_dword(pdev, pos + PCI_DVSEC_HEADER1, &hdr);
296 		vid = PCI_DVSEC_HEADER1_VID(hdr);
297 		if (vid != PCI_VENDOR_ID_INTEL)
298 			continue;
299 
300 		/* Support only revision 1 */
301 		header.rev = PCI_DVSEC_HEADER1_REV(hdr);
302 		if (header.rev != 1) {
303 			dev_info(&pdev->dev, "Unsupported DVSEC revision %d\n", header.rev);
304 			continue;
305 		}
306 
307 		header.length = PCI_DVSEC_HEADER1_LEN(hdr);
308 
309 		pci_read_config_byte(pdev, pos + INTEL_DVSEC_ENTRIES, &header.num_entries);
310 		pci_read_config_byte(pdev, pos + INTEL_DVSEC_SIZE, &header.entry_size);
311 		pci_read_config_dword(pdev, pos + INTEL_DVSEC_TABLE, &table);
312 
313 		header.tbir = INTEL_DVSEC_TABLE_BAR(table);
314 		header.offset = INTEL_DVSEC_TABLE_OFFSET(table);
315 
316 		pci_read_config_dword(pdev, pos + PCI_DVSEC_HEADER2, &hdr);
317 		header.id = PCI_DVSEC_HEADER2_ID(hdr);
318 
319 		ret = intel_vsec_add_dev(pdev, &header, info);
320 		if (ret)
321 			continue;
322 
323 		have_devices = true;
324 	} while (true);
325 
326 	return have_devices;
327 }
328 
329 static bool intel_vsec_walk_vsec(struct pci_dev *pdev,
330 				 struct intel_vsec_platform_info *info)
331 {
332 	bool have_devices = false;
333 	int pos = 0;
334 
335 	do {
336 		struct intel_vsec_header header;
337 		u32 table, hdr;
338 		int ret;
339 
340 		pos = pci_find_next_ext_capability(pdev, pos, PCI_EXT_CAP_ID_VNDR);
341 		if (!pos)
342 			break;
343 
344 		pci_read_config_dword(pdev, pos + PCI_VNDR_HEADER, &hdr);
345 
346 		/* Support only revision 1 */
347 		header.rev = PCI_VNDR_HEADER_REV(hdr);
348 		if (header.rev != 1) {
349 			dev_info(&pdev->dev, "Unsupported VSEC revision %d\n", header.rev);
350 			continue;
351 		}
352 
353 		header.id = PCI_VNDR_HEADER_ID(hdr);
354 		header.length = PCI_VNDR_HEADER_LEN(hdr);
355 
356 		/* entry, size, and table offset are the same as DVSEC */
357 		pci_read_config_byte(pdev, pos + INTEL_DVSEC_ENTRIES, &header.num_entries);
358 		pci_read_config_byte(pdev, pos + INTEL_DVSEC_SIZE, &header.entry_size);
359 		pci_read_config_dword(pdev, pos + INTEL_DVSEC_TABLE, &table);
360 
361 		header.tbir = INTEL_DVSEC_TABLE_BAR(table);
362 		header.offset = INTEL_DVSEC_TABLE_OFFSET(table);
363 
364 		ret = intel_vsec_add_dev(pdev, &header, info);
365 		if (ret)
366 			continue;
367 
368 		have_devices = true;
369 	} while (true);
370 
371 	return have_devices;
372 }
373 
374 static int intel_vsec_pci_probe(struct pci_dev *pdev, const struct pci_device_id *id)
375 {
376 	struct intel_vsec_platform_info *info;
377 	bool have_devices = false;
378 	int ret;
379 
380 	ret = pcim_enable_device(pdev);
381 	if (ret)
382 		return ret;
383 
384 	pci_save_state(pdev);
385 	info = (struct intel_vsec_platform_info *)id->driver_data;
386 	if (!info)
387 		return -EINVAL;
388 
389 	if (intel_vsec_walk_dvsec(pdev, info))
390 		have_devices = true;
391 
392 	if (intel_vsec_walk_vsec(pdev, info))
393 		have_devices = true;
394 
395 	if (info && (info->quirks & VSEC_QUIRK_NO_DVSEC) &&
396 	    intel_vsec_walk_header(pdev, info))
397 		have_devices = true;
398 
399 	if (!have_devices)
400 		return -ENODEV;
401 
402 	return 0;
403 }
404 
405 /* TGL info */
406 static const struct intel_vsec_platform_info tgl_info = {
407 	.quirks = VSEC_QUIRK_NO_WATCHER | VSEC_QUIRK_NO_CRASHLOG |
408 		  VSEC_QUIRK_TABLE_SHIFT | VSEC_QUIRK_EARLY_HW,
409 };
410 
411 /* DG1 info */
412 static struct intel_vsec_header dg1_telemetry = {
413 	.length = 0x10,
414 	.id = 2,
415 	.num_entries = 1,
416 	.entry_size = 3,
417 	.tbir = 0,
418 	.offset = 0x466000,
419 };
420 
421 static struct intel_vsec_header *dg1_capabilities[] = {
422 	&dg1_telemetry,
423 	NULL
424 };
425 
426 static const struct intel_vsec_platform_info dg1_info = {
427 	.capabilities = dg1_capabilities,
428 	.quirks = VSEC_QUIRK_NO_DVSEC | VSEC_QUIRK_EARLY_HW,
429 };
430 
431 /* MTL info */
432 static const struct intel_vsec_platform_info mtl_info = {
433 	.quirks = VSEC_QUIRK_NO_WATCHER | VSEC_QUIRK_NO_CRASHLOG,
434 };
435 
436 #define PCI_DEVICE_ID_INTEL_VSEC_ADL		0x467d
437 #define PCI_DEVICE_ID_INTEL_VSEC_DG1		0x490e
438 #define PCI_DEVICE_ID_INTEL_VSEC_MTL_M		0x7d0d
439 #define PCI_DEVICE_ID_INTEL_VSEC_MTL_S		0xad0d
440 #define PCI_DEVICE_ID_INTEL_VSEC_OOBMSM		0x09a7
441 #define PCI_DEVICE_ID_INTEL_VSEC_RPL		0xa77d
442 #define PCI_DEVICE_ID_INTEL_VSEC_TGL		0x9a0d
443 static const struct pci_device_id intel_vsec_pci_ids[] = {
444 	{ PCI_DEVICE_DATA(INTEL, VSEC_ADL, &tgl_info) },
445 	{ PCI_DEVICE_DATA(INTEL, VSEC_DG1, &dg1_info) },
446 	{ PCI_DEVICE_DATA(INTEL, VSEC_MTL_M, &mtl_info) },
447 	{ PCI_DEVICE_DATA(INTEL, VSEC_MTL_S, &mtl_info) },
448 	{ PCI_DEVICE_DATA(INTEL, VSEC_OOBMSM, &(struct intel_vsec_platform_info) {}) },
449 	{ PCI_DEVICE_DATA(INTEL, VSEC_RPL, &tgl_info) },
450 	{ PCI_DEVICE_DATA(INTEL, VSEC_TGL, &tgl_info) },
451 	{ }
452 };
453 MODULE_DEVICE_TABLE(pci, intel_vsec_pci_ids);
454 
455 static pci_ers_result_t intel_vsec_pci_error_detected(struct pci_dev *pdev,
456 						      pci_channel_state_t state)
457 {
458 	pci_ers_result_t status = PCI_ERS_RESULT_NEED_RESET;
459 
460 	dev_info(&pdev->dev, "PCI error detected, state %d", state);
461 
462 	if (state == pci_channel_io_perm_failure)
463 		status = PCI_ERS_RESULT_DISCONNECT;
464 	else
465 		pci_disable_device(pdev);
466 
467 	return status;
468 }
469 
470 static pci_ers_result_t intel_vsec_pci_slot_reset(struct pci_dev *pdev)
471 {
472 	struct intel_vsec_device *intel_vsec_dev;
473 	pci_ers_result_t status = PCI_ERS_RESULT_DISCONNECT;
474 	const struct pci_device_id *pci_dev_id;
475 	unsigned long index;
476 
477 	dev_info(&pdev->dev, "Resetting PCI slot\n");
478 
479 	msleep(2000);
480 	if (pci_enable_device(pdev)) {
481 		dev_info(&pdev->dev,
482 			 "Failed to re-enable PCI device after reset.\n");
483 		goto out;
484 	}
485 
486 	status = PCI_ERS_RESULT_RECOVERED;
487 
488 	xa_for_each(&auxdev_array, index, intel_vsec_dev) {
489 		/* check if pdev doesn't match */
490 		if (pdev != intel_vsec_dev->pcidev)
491 			continue;
492 		devm_release_action(&pdev->dev, intel_vsec_remove_aux,
493 				    &intel_vsec_dev->auxdev);
494 	}
495 	pci_disable_device(pdev);
496 	pci_restore_state(pdev);
497 	pci_dev_id = pci_match_id(intel_vsec_pci_ids, pdev);
498 	intel_vsec_pci_probe(pdev, pci_dev_id);
499 
500 out:
501 	return status;
502 }
503 
504 static void intel_vsec_pci_resume(struct pci_dev *pdev)
505 {
506 	dev_info(&pdev->dev, "Done resuming PCI device\n");
507 }
508 
509 static const struct pci_error_handlers intel_vsec_pci_err_handlers = {
510 	.error_detected = intel_vsec_pci_error_detected,
511 	.slot_reset = intel_vsec_pci_slot_reset,
512 	.resume = intel_vsec_pci_resume,
513 };
514 
515 static struct pci_driver intel_vsec_pci_driver = {
516 	.name = "intel_vsec",
517 	.id_table = intel_vsec_pci_ids,
518 	.probe = intel_vsec_pci_probe,
519 	.err_handler = &intel_vsec_pci_err_handlers,
520 };
521 module_pci_driver(intel_vsec_pci_driver);
522 
523 MODULE_AUTHOR("David E. Box <david.e.box@linux.intel.com>");
524 MODULE_DESCRIPTION("Intel Extended Capabilities auxiliary bus driver");
525 MODULE_LICENSE("GPL v2");
526