xref: /openbmc/linux/drivers/platform/x86/intel/vsec.c (revision 2984f26a)
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 const char *intel_vsec_name(enum intel_vsec_id id)
71 {
72 	switch (id) {
73 	case VSEC_ID_TELEMETRY:
74 		return "telemetry";
75 
76 	case VSEC_ID_WATCHER:
77 		return "watcher";
78 
79 	case VSEC_ID_CRASHLOG:
80 		return "crashlog";
81 
82 	case VSEC_ID_SDSI:
83 		return "sdsi";
84 
85 	case VSEC_ID_TPMI:
86 		return "tpmi";
87 
88 	default:
89 		return NULL;
90 	}
91 }
92 
93 static bool intel_vsec_supported(u16 id, unsigned long caps)
94 {
95 	switch (id) {
96 	case VSEC_ID_TELEMETRY:
97 		return !!(caps & VSEC_CAP_TELEMETRY);
98 	case VSEC_ID_WATCHER:
99 		return !!(caps & VSEC_CAP_WATCHER);
100 	case VSEC_ID_CRASHLOG:
101 		return !!(caps & VSEC_CAP_CRASHLOG);
102 	case VSEC_ID_SDSI:
103 		return !!(caps & VSEC_CAP_SDSI);
104 	case VSEC_ID_TPMI:
105 		return !!(caps & VSEC_CAP_TPMI);
106 	default:
107 		return false;
108 	}
109 }
110 
111 static void intel_vsec_remove_aux(void *data)
112 {
113 	auxiliary_device_delete(data);
114 	auxiliary_device_uninit(data);
115 }
116 
117 static DEFINE_MUTEX(vsec_ida_lock);
118 
119 static void intel_vsec_dev_release(struct device *dev)
120 {
121 	struct intel_vsec_device *intel_vsec_dev = dev_to_ivdev(dev);
122 
123 	xa_erase(&auxdev_array, intel_vsec_dev->id);
124 
125 	mutex_lock(&vsec_ida_lock);
126 	ida_free(intel_vsec_dev->ida, intel_vsec_dev->auxdev.id);
127 	mutex_unlock(&vsec_ida_lock);
128 
129 	kfree(intel_vsec_dev->resource);
130 	kfree(intel_vsec_dev);
131 }
132 
133 int intel_vsec_add_aux(struct pci_dev *pdev, struct device *parent,
134 		       struct intel_vsec_device *intel_vsec_dev,
135 		       const char *name)
136 {
137 	struct auxiliary_device *auxdev = &intel_vsec_dev->auxdev;
138 	int ret, id;
139 
140 	ret = xa_alloc(&auxdev_array, &intel_vsec_dev->id, intel_vsec_dev,
141 		       PMT_XA_LIMIT, GFP_KERNEL);
142 	if (ret < 0) {
143 		kfree(intel_vsec_dev->resource);
144 		kfree(intel_vsec_dev);
145 		return ret;
146 	}
147 
148 	mutex_lock(&vsec_ida_lock);
149 	id = ida_alloc(intel_vsec_dev->ida, GFP_KERNEL);
150 	mutex_unlock(&vsec_ida_lock);
151 	if (id < 0) {
152 		xa_erase(&auxdev_array, intel_vsec_dev->id);
153 		kfree(intel_vsec_dev->resource);
154 		kfree(intel_vsec_dev);
155 		return id;
156 	}
157 
158 	if (!parent)
159 		parent = &pdev->dev;
160 
161 	auxdev->id = id;
162 	auxdev->name = name;
163 	auxdev->dev.parent = parent;
164 	auxdev->dev.release = intel_vsec_dev_release;
165 
166 	ret = auxiliary_device_init(auxdev);
167 	if (ret < 0) {
168 		intel_vsec_dev_release(&auxdev->dev);
169 		return ret;
170 	}
171 
172 	ret = auxiliary_device_add(auxdev);
173 	if (ret < 0) {
174 		auxiliary_device_uninit(auxdev);
175 		return ret;
176 	}
177 
178 	ret = devm_add_action_or_reset(parent, intel_vsec_remove_aux,
179 				       auxdev);
180 	if (ret < 0)
181 		return ret;
182 
183 	return 0;
184 }
185 EXPORT_SYMBOL_NS_GPL(intel_vsec_add_aux, INTEL_VSEC);
186 
187 static int intel_vsec_add_dev(struct pci_dev *pdev, struct intel_vsec_header *header,
188 			      struct intel_vsec_platform_info *info)
189 {
190 	struct intel_vsec_device *intel_vsec_dev;
191 	struct resource *res, *tmp;
192 	unsigned long quirks = info->quirks;
193 	int i;
194 
195 	if (!intel_vsec_supported(header->id, info->caps))
196 		return -EINVAL;
197 
198 	if (!header->num_entries) {
199 		dev_dbg(&pdev->dev, "Invalid 0 entry count for header id %d\n", header->id);
200 		return -EINVAL;
201 	}
202 
203 	if (!header->entry_size) {
204 		dev_dbg(&pdev->dev, "Invalid 0 entry size for header id %d\n", header->id);
205 		return -EINVAL;
206 	}
207 
208 	intel_vsec_dev = kzalloc(sizeof(*intel_vsec_dev), GFP_KERNEL);
209 	if (!intel_vsec_dev)
210 		return -ENOMEM;
211 
212 	res = kcalloc(header->num_entries, sizeof(*res), GFP_KERNEL);
213 	if (!res) {
214 		kfree(intel_vsec_dev);
215 		return -ENOMEM;
216 	}
217 
218 	if (quirks & VSEC_QUIRK_TABLE_SHIFT)
219 		header->offset >>= TABLE_OFFSET_SHIFT;
220 
221 	/*
222 	 * The DVSEC/VSEC contains the starting offset and count for a block of
223 	 * discovery tables. Create a resource array of these tables to the
224 	 * auxiliary device driver.
225 	 */
226 	for (i = 0, tmp = res; i < header->num_entries; i++, tmp++) {
227 		tmp->start = pdev->resource[header->tbir].start +
228 			     header->offset + i * (header->entry_size * sizeof(u32));
229 		tmp->end = tmp->start + (header->entry_size * sizeof(u32)) - 1;
230 		tmp->flags = IORESOURCE_MEM;
231 	}
232 
233 	intel_vsec_dev->pcidev = pdev;
234 	intel_vsec_dev->resource = res;
235 	intel_vsec_dev->num_resources = header->num_entries;
236 	intel_vsec_dev->info = info;
237 
238 	if (header->id == VSEC_ID_SDSI)
239 		intel_vsec_dev->ida = &intel_vsec_sdsi_ida;
240 	else
241 		intel_vsec_dev->ida = &intel_vsec_ida;
242 
243 	return intel_vsec_add_aux(pdev, NULL, intel_vsec_dev,
244 				  intel_vsec_name(header->id));
245 }
246 
247 static bool intel_vsec_walk_header(struct pci_dev *pdev,
248 				   struct intel_vsec_platform_info *info)
249 {
250 	struct intel_vsec_header **header = info->headers;
251 	bool have_devices = false;
252 	int ret;
253 
254 	for ( ; *header; header++) {
255 		ret = intel_vsec_add_dev(pdev, *header, info);
256 		if (ret)
257 			dev_info(&pdev->dev, "Could not add device for VSEC id %d\n",
258 				 (*header)->id);
259 		else
260 			have_devices = true;
261 	}
262 
263 	return have_devices;
264 }
265 
266 static bool intel_vsec_walk_dvsec(struct pci_dev *pdev,
267 				  struct intel_vsec_platform_info *info)
268 {
269 	bool have_devices = false;
270 	int pos = 0;
271 
272 	do {
273 		struct intel_vsec_header header;
274 		u32 table, hdr;
275 		u16 vid;
276 		int ret;
277 
278 		pos = pci_find_next_ext_capability(pdev, pos, PCI_EXT_CAP_ID_DVSEC);
279 		if (!pos)
280 			break;
281 
282 		pci_read_config_dword(pdev, pos + PCI_DVSEC_HEADER1, &hdr);
283 		vid = PCI_DVSEC_HEADER1_VID(hdr);
284 		if (vid != PCI_VENDOR_ID_INTEL)
285 			continue;
286 
287 		/* Support only revision 1 */
288 		header.rev = PCI_DVSEC_HEADER1_REV(hdr);
289 		if (header.rev != 1) {
290 			dev_info(&pdev->dev, "Unsupported DVSEC revision %d\n", header.rev);
291 			continue;
292 		}
293 
294 		header.length = PCI_DVSEC_HEADER1_LEN(hdr);
295 
296 		pci_read_config_byte(pdev, pos + INTEL_DVSEC_ENTRIES, &header.num_entries);
297 		pci_read_config_byte(pdev, pos + INTEL_DVSEC_SIZE, &header.entry_size);
298 		pci_read_config_dword(pdev, pos + INTEL_DVSEC_TABLE, &table);
299 
300 		header.tbir = INTEL_DVSEC_TABLE_BAR(table);
301 		header.offset = INTEL_DVSEC_TABLE_OFFSET(table);
302 
303 		pci_read_config_dword(pdev, pos + PCI_DVSEC_HEADER2, &hdr);
304 		header.id = PCI_DVSEC_HEADER2_ID(hdr);
305 
306 		ret = intel_vsec_add_dev(pdev, &header, info);
307 		if (ret)
308 			continue;
309 
310 		have_devices = true;
311 	} while (true);
312 
313 	return have_devices;
314 }
315 
316 static bool intel_vsec_walk_vsec(struct pci_dev *pdev,
317 				 struct intel_vsec_platform_info *info)
318 {
319 	bool have_devices = false;
320 	int pos = 0;
321 
322 	do {
323 		struct intel_vsec_header header;
324 		u32 table, hdr;
325 		int ret;
326 
327 		pos = pci_find_next_ext_capability(pdev, pos, PCI_EXT_CAP_ID_VNDR);
328 		if (!pos)
329 			break;
330 
331 		pci_read_config_dword(pdev, pos + PCI_VNDR_HEADER, &hdr);
332 
333 		/* Support only revision 1 */
334 		header.rev = PCI_VNDR_HEADER_REV(hdr);
335 		if (header.rev != 1) {
336 			dev_info(&pdev->dev, "Unsupported VSEC revision %d\n", header.rev);
337 			continue;
338 		}
339 
340 		header.id = PCI_VNDR_HEADER_ID(hdr);
341 		header.length = PCI_VNDR_HEADER_LEN(hdr);
342 
343 		/* entry, size, and table offset are the same as DVSEC */
344 		pci_read_config_byte(pdev, pos + INTEL_DVSEC_ENTRIES, &header.num_entries);
345 		pci_read_config_byte(pdev, pos + INTEL_DVSEC_SIZE, &header.entry_size);
346 		pci_read_config_dword(pdev, pos + INTEL_DVSEC_TABLE, &table);
347 
348 		header.tbir = INTEL_DVSEC_TABLE_BAR(table);
349 		header.offset = INTEL_DVSEC_TABLE_OFFSET(table);
350 
351 		ret = intel_vsec_add_dev(pdev, &header, info);
352 		if (ret)
353 			continue;
354 
355 		have_devices = true;
356 	} while (true);
357 
358 	return have_devices;
359 }
360 
361 static int intel_vsec_pci_probe(struct pci_dev *pdev, const struct pci_device_id *id)
362 {
363 	struct intel_vsec_platform_info *info;
364 	bool have_devices = false;
365 	int ret;
366 
367 	ret = pcim_enable_device(pdev);
368 	if (ret)
369 		return ret;
370 
371 	pci_save_state(pdev);
372 	info = (struct intel_vsec_platform_info *)id->driver_data;
373 	if (!info)
374 		return -EINVAL;
375 
376 	if (intel_vsec_walk_dvsec(pdev, info))
377 		have_devices = true;
378 
379 	if (intel_vsec_walk_vsec(pdev, info))
380 		have_devices = true;
381 
382 	if (info && (info->quirks & VSEC_QUIRK_NO_DVSEC) &&
383 	    intel_vsec_walk_header(pdev, info))
384 		have_devices = true;
385 
386 	if (!have_devices)
387 		return -ENODEV;
388 
389 	return 0;
390 }
391 
392 /* DG1 info */
393 static struct intel_vsec_header dg1_header = {
394 	.length = 0x10,
395 	.id = 2,
396 	.num_entries = 1,
397 	.entry_size = 3,
398 	.tbir = 0,
399 	.offset = 0x466000,
400 };
401 
402 static struct intel_vsec_header *dg1_headers[] = {
403 	&dg1_header,
404 	NULL
405 };
406 
407 static const struct intel_vsec_platform_info dg1_info = {
408 	.caps = VSEC_CAP_TELEMETRY,
409 	.headers = dg1_headers,
410 	.quirks = VSEC_QUIRK_NO_DVSEC | VSEC_QUIRK_EARLY_HW,
411 };
412 
413 /* MTL info */
414 static const struct intel_vsec_platform_info mtl_info = {
415 	.caps = VSEC_CAP_TELEMETRY,
416 };
417 
418 /* OOBMSM info */
419 static const struct intel_vsec_platform_info oobmsm_info = {
420 	.caps = VSEC_CAP_TELEMETRY | VSEC_CAP_SDSI | VSEC_CAP_TPMI,
421 };
422 
423 /* TGL info */
424 static const struct intel_vsec_platform_info tgl_info = {
425 	.caps = VSEC_CAP_TELEMETRY,
426 	.quirks = VSEC_QUIRK_TABLE_SHIFT | VSEC_QUIRK_EARLY_HW,
427 };
428 
429 #define PCI_DEVICE_ID_INTEL_VSEC_ADL		0x467d
430 #define PCI_DEVICE_ID_INTEL_VSEC_DG1		0x490e
431 #define PCI_DEVICE_ID_INTEL_VSEC_MTL_M		0x7d0d
432 #define PCI_DEVICE_ID_INTEL_VSEC_MTL_S		0xad0d
433 #define PCI_DEVICE_ID_INTEL_VSEC_OOBMSM		0x09a7
434 #define PCI_DEVICE_ID_INTEL_VSEC_RPL		0xa77d
435 #define PCI_DEVICE_ID_INTEL_VSEC_TGL		0x9a0d
436 static const struct pci_device_id intel_vsec_pci_ids[] = {
437 	{ PCI_DEVICE_DATA(INTEL, VSEC_ADL, &tgl_info) },
438 	{ PCI_DEVICE_DATA(INTEL, VSEC_DG1, &dg1_info) },
439 	{ PCI_DEVICE_DATA(INTEL, VSEC_MTL_M, &mtl_info) },
440 	{ PCI_DEVICE_DATA(INTEL, VSEC_MTL_S, &mtl_info) },
441 	{ PCI_DEVICE_DATA(INTEL, VSEC_OOBMSM, &oobmsm_info) },
442 	{ PCI_DEVICE_DATA(INTEL, VSEC_RPL, &tgl_info) },
443 	{ PCI_DEVICE_DATA(INTEL, VSEC_TGL, &tgl_info) },
444 	{ }
445 };
446 MODULE_DEVICE_TABLE(pci, intel_vsec_pci_ids);
447 
448 static pci_ers_result_t intel_vsec_pci_error_detected(struct pci_dev *pdev,
449 						      pci_channel_state_t state)
450 {
451 	pci_ers_result_t status = PCI_ERS_RESULT_NEED_RESET;
452 
453 	dev_info(&pdev->dev, "PCI error detected, state %d", state);
454 
455 	if (state == pci_channel_io_perm_failure)
456 		status = PCI_ERS_RESULT_DISCONNECT;
457 	else
458 		pci_disable_device(pdev);
459 
460 	return status;
461 }
462 
463 static pci_ers_result_t intel_vsec_pci_slot_reset(struct pci_dev *pdev)
464 {
465 	struct intel_vsec_device *intel_vsec_dev;
466 	pci_ers_result_t status = PCI_ERS_RESULT_DISCONNECT;
467 	const struct pci_device_id *pci_dev_id;
468 	unsigned long index;
469 
470 	dev_info(&pdev->dev, "Resetting PCI slot\n");
471 
472 	msleep(2000);
473 	if (pci_enable_device(pdev)) {
474 		dev_info(&pdev->dev,
475 			 "Failed to re-enable PCI device after reset.\n");
476 		goto out;
477 	}
478 
479 	status = PCI_ERS_RESULT_RECOVERED;
480 
481 	xa_for_each(&auxdev_array, index, intel_vsec_dev) {
482 		/* check if pdev doesn't match */
483 		if (pdev != intel_vsec_dev->pcidev)
484 			continue;
485 		devm_release_action(&pdev->dev, intel_vsec_remove_aux,
486 				    &intel_vsec_dev->auxdev);
487 	}
488 	pci_disable_device(pdev);
489 	pci_restore_state(pdev);
490 	pci_dev_id = pci_match_id(intel_vsec_pci_ids, pdev);
491 	intel_vsec_pci_probe(pdev, pci_dev_id);
492 
493 out:
494 	return status;
495 }
496 
497 static void intel_vsec_pci_resume(struct pci_dev *pdev)
498 {
499 	dev_info(&pdev->dev, "Done resuming PCI device\n");
500 }
501 
502 static const struct pci_error_handlers intel_vsec_pci_err_handlers = {
503 	.error_detected = intel_vsec_pci_error_detected,
504 	.slot_reset = intel_vsec_pci_slot_reset,
505 	.resume = intel_vsec_pci_resume,
506 };
507 
508 static struct pci_driver intel_vsec_pci_driver = {
509 	.name = "intel_vsec",
510 	.id_table = intel_vsec_pci_ids,
511 	.probe = intel_vsec_pci_probe,
512 	.err_handler = &intel_vsec_pci_err_handlers,
513 };
514 module_pci_driver(intel_vsec_pci_driver);
515 
516 MODULE_AUTHOR("David E. Box <david.e.box@linux.intel.com>");
517 MODULE_DESCRIPTION("Intel Extended Capabilities auxiliary bus driver");
518 MODULE_LICENSE("GPL v2");
519