xref: /openbmc/linux/drivers/platform/x86/intel/vsec.c (revision 12cecbf9)
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 };
68 
69 static enum intel_vsec_id intel_vsec_allow_list[] = {
70 	VSEC_ID_TELEMETRY,
71 	VSEC_ID_WATCHER,
72 	VSEC_ID_CRASHLOG,
73 	VSEC_ID_SDSI,
74 };
75 
76 static const char *intel_vsec_name(enum intel_vsec_id id)
77 {
78 	switch (id) {
79 	case VSEC_ID_TELEMETRY:
80 		return "telemetry";
81 
82 	case VSEC_ID_WATCHER:
83 		return "watcher";
84 
85 	case VSEC_ID_CRASHLOG:
86 		return "crashlog";
87 
88 	case VSEC_ID_SDSI:
89 		return "sdsi";
90 
91 	default:
92 		return NULL;
93 	}
94 }
95 
96 static bool intel_vsec_allowed(u16 id)
97 {
98 	int i;
99 
100 	for (i = 0; i < ARRAY_SIZE(intel_vsec_allow_list); i++)
101 		if (intel_vsec_allow_list[i] == id)
102 			return true;
103 
104 	return false;
105 }
106 
107 static bool intel_vsec_disabled(u16 id, unsigned long quirks)
108 {
109 	switch (id) {
110 	case VSEC_ID_WATCHER:
111 		return !!(quirks & VSEC_QUIRK_NO_WATCHER);
112 
113 	case VSEC_ID_CRASHLOG:
114 		return !!(quirks & VSEC_QUIRK_NO_CRASHLOG);
115 
116 	default:
117 		return false;
118 	}
119 }
120 
121 static void intel_vsec_remove_aux(void *data)
122 {
123 	auxiliary_device_delete(data);
124 	auxiliary_device_uninit(data);
125 }
126 
127 static void intel_vsec_dev_release(struct device *dev)
128 {
129 	struct intel_vsec_device *intel_vsec_dev = dev_to_ivdev(dev);
130 
131 	ida_free(intel_vsec_dev->ida, intel_vsec_dev->auxdev.id);
132 	kfree(intel_vsec_dev->resource);
133 	kfree(intel_vsec_dev);
134 }
135 
136 static int intel_vsec_add_aux(struct pci_dev *pdev, struct intel_vsec_device *intel_vsec_dev,
137 			      const char *name)
138 {
139 	struct auxiliary_device *auxdev = &intel_vsec_dev->auxdev;
140 	int ret, id;
141 
142 	ret = ida_alloc(intel_vsec_dev->ida, GFP_KERNEL);
143 	if (ret < 0) {
144 		kfree(intel_vsec_dev);
145 		return ret;
146 	}
147 
148 	auxdev->id = ret;
149 	auxdev->name = name;
150 	auxdev->dev.parent = &pdev->dev;
151 	auxdev->dev.release = intel_vsec_dev_release;
152 
153 	ret = auxiliary_device_init(auxdev);
154 	if (ret < 0) {
155 		ida_free(intel_vsec_dev->ida, auxdev->id);
156 		kfree(intel_vsec_dev->resource);
157 		kfree(intel_vsec_dev);
158 		return ret;
159 	}
160 
161 	ret = auxiliary_device_add(auxdev);
162 	if (ret < 0) {
163 		auxiliary_device_uninit(auxdev);
164 		return ret;
165 	}
166 
167 	ret = devm_add_action_or_reset(&pdev->dev, intel_vsec_remove_aux,
168 				       auxdev);
169 	if (ret < 0)
170 		return ret;
171 
172 	/* Add auxdev to list */
173 	ret = xa_alloc(&auxdev_array, &id, intel_vsec_dev, PMT_XA_LIMIT,
174 		       GFP_KERNEL);
175 	if (ret)
176 		return ret;
177 
178 	return 0;
179 }
180 
181 static int intel_vsec_add_dev(struct pci_dev *pdev, struct intel_vsec_header *header,
182 			      struct intel_vsec_platform_info *info)
183 {
184 	struct intel_vsec_device *intel_vsec_dev;
185 	struct resource *res, *tmp;
186 	unsigned long quirks = info->quirks;
187 	int i;
188 
189 	if (!intel_vsec_allowed(header->id) || intel_vsec_disabled(header->id, quirks))
190 		return -EINVAL;
191 
192 	if (!header->num_entries) {
193 		dev_dbg(&pdev->dev, "Invalid 0 entry count for header id %d\n", header->id);
194 		return -EINVAL;
195 	}
196 
197 	if (!header->entry_size) {
198 		dev_dbg(&pdev->dev, "Invalid 0 entry size for header id %d\n", header->id);
199 		return -EINVAL;
200 	}
201 
202 	intel_vsec_dev = kzalloc(sizeof(*intel_vsec_dev), GFP_KERNEL);
203 	if (!intel_vsec_dev)
204 		return -ENOMEM;
205 
206 	res = kcalloc(header->num_entries, sizeof(*res), GFP_KERNEL);
207 	if (!res) {
208 		kfree(intel_vsec_dev);
209 		return -ENOMEM;
210 	}
211 
212 	if (quirks & VSEC_QUIRK_TABLE_SHIFT)
213 		header->offset >>= TABLE_OFFSET_SHIFT;
214 
215 	/*
216 	 * The DVSEC/VSEC contains the starting offset and count for a block of
217 	 * discovery tables. Create a resource array of these tables to the
218 	 * auxiliary device driver.
219 	 */
220 	for (i = 0, tmp = res; i < header->num_entries; i++, tmp++) {
221 		tmp->start = pdev->resource[header->tbir].start +
222 			     header->offset + i * (header->entry_size * sizeof(u32));
223 		tmp->end = tmp->start + (header->entry_size * sizeof(u32)) - 1;
224 		tmp->flags = IORESOURCE_MEM;
225 	}
226 
227 	intel_vsec_dev->pcidev = pdev;
228 	intel_vsec_dev->resource = res;
229 	intel_vsec_dev->num_resources = header->num_entries;
230 	intel_vsec_dev->info = info;
231 
232 	if (header->id == VSEC_ID_SDSI)
233 		intel_vsec_dev->ida = &intel_vsec_sdsi_ida;
234 	else
235 		intel_vsec_dev->ida = &intel_vsec_ida;
236 
237 	return intel_vsec_add_aux(pdev, intel_vsec_dev, intel_vsec_name(header->id));
238 }
239 
240 static bool intel_vsec_walk_header(struct pci_dev *pdev,
241 				   struct intel_vsec_platform_info *info)
242 {
243 	struct intel_vsec_header **header = info->capabilities;
244 	bool have_devices = false;
245 	int ret;
246 
247 	for ( ; *header; header++) {
248 		ret = intel_vsec_add_dev(pdev, *header, info);
249 		if (ret)
250 			dev_info(&pdev->dev, "Could not add device for DVSEC id %d\n",
251 				 (*header)->id);
252 		else
253 			have_devices = true;
254 	}
255 
256 	return have_devices;
257 }
258 
259 static bool intel_vsec_walk_dvsec(struct pci_dev *pdev,
260 				  struct intel_vsec_platform_info *info)
261 {
262 	bool have_devices = false;
263 	int pos = 0;
264 
265 	do {
266 		struct intel_vsec_header header;
267 		u32 table, hdr;
268 		u16 vid;
269 		int ret;
270 
271 		pos = pci_find_next_ext_capability(pdev, pos, PCI_EXT_CAP_ID_DVSEC);
272 		if (!pos)
273 			break;
274 
275 		pci_read_config_dword(pdev, pos + PCI_DVSEC_HEADER1, &hdr);
276 		vid = PCI_DVSEC_HEADER1_VID(hdr);
277 		if (vid != PCI_VENDOR_ID_INTEL)
278 			continue;
279 
280 		/* Support only revision 1 */
281 		header.rev = PCI_DVSEC_HEADER1_REV(hdr);
282 		if (header.rev != 1) {
283 			dev_info(&pdev->dev, "Unsupported DVSEC revision %d\n", header.rev);
284 			continue;
285 		}
286 
287 		header.length = PCI_DVSEC_HEADER1_LEN(hdr);
288 
289 		pci_read_config_byte(pdev, pos + INTEL_DVSEC_ENTRIES, &header.num_entries);
290 		pci_read_config_byte(pdev, pos + INTEL_DVSEC_SIZE, &header.entry_size);
291 		pci_read_config_dword(pdev, pos + INTEL_DVSEC_TABLE, &table);
292 
293 		header.tbir = INTEL_DVSEC_TABLE_BAR(table);
294 		header.offset = INTEL_DVSEC_TABLE_OFFSET(table);
295 
296 		pci_read_config_dword(pdev, pos + PCI_DVSEC_HEADER2, &hdr);
297 		header.id = PCI_DVSEC_HEADER2_ID(hdr);
298 
299 		ret = intel_vsec_add_dev(pdev, &header, info);
300 		if (ret)
301 			continue;
302 
303 		have_devices = true;
304 	} while (true);
305 
306 	return have_devices;
307 }
308 
309 static bool intel_vsec_walk_vsec(struct pci_dev *pdev,
310 				 struct intel_vsec_platform_info *info)
311 {
312 	bool have_devices = false;
313 	int pos = 0;
314 
315 	do {
316 		struct intel_vsec_header header;
317 		u32 table, hdr;
318 		int ret;
319 
320 		pos = pci_find_next_ext_capability(pdev, pos, PCI_EXT_CAP_ID_VNDR);
321 		if (!pos)
322 			break;
323 
324 		pci_read_config_dword(pdev, pos + PCI_VNDR_HEADER, &hdr);
325 
326 		/* Support only revision 1 */
327 		header.rev = PCI_VNDR_HEADER_REV(hdr);
328 		if (header.rev != 1) {
329 			dev_info(&pdev->dev, "Unsupported VSEC revision %d\n", header.rev);
330 			continue;
331 		}
332 
333 		header.id = PCI_VNDR_HEADER_ID(hdr);
334 		header.length = PCI_VNDR_HEADER_LEN(hdr);
335 
336 		/* entry, size, and table offset are the same as DVSEC */
337 		pci_read_config_byte(pdev, pos + INTEL_DVSEC_ENTRIES, &header.num_entries);
338 		pci_read_config_byte(pdev, pos + INTEL_DVSEC_SIZE, &header.entry_size);
339 		pci_read_config_dword(pdev, pos + INTEL_DVSEC_TABLE, &table);
340 
341 		header.tbir = INTEL_DVSEC_TABLE_BAR(table);
342 		header.offset = INTEL_DVSEC_TABLE_OFFSET(table);
343 
344 		ret = intel_vsec_add_dev(pdev, &header, info);
345 		if (ret)
346 			continue;
347 
348 		have_devices = true;
349 	} while (true);
350 
351 	return have_devices;
352 }
353 
354 static int intel_vsec_pci_probe(struct pci_dev *pdev, const struct pci_device_id *id)
355 {
356 	struct intel_vsec_platform_info *info;
357 	bool have_devices = false;
358 	int ret;
359 
360 	ret = pcim_enable_device(pdev);
361 	if (ret)
362 		return ret;
363 
364 	pci_save_state(pdev);
365 	info = (struct intel_vsec_platform_info *)id->driver_data;
366 	if (!info)
367 		return -EINVAL;
368 
369 	if (intel_vsec_walk_dvsec(pdev, info))
370 		have_devices = true;
371 
372 	if (intel_vsec_walk_vsec(pdev, info))
373 		have_devices = true;
374 
375 	if (info && (info->quirks & VSEC_QUIRK_NO_DVSEC) &&
376 	    intel_vsec_walk_header(pdev, info))
377 		have_devices = true;
378 
379 	if (!have_devices)
380 		return -ENODEV;
381 
382 	return 0;
383 }
384 
385 /* TGL info */
386 static const struct intel_vsec_platform_info tgl_info = {
387 	.quirks = VSEC_QUIRK_NO_WATCHER | VSEC_QUIRK_NO_CRASHLOG |
388 		  VSEC_QUIRK_TABLE_SHIFT | VSEC_QUIRK_EARLY_HW,
389 };
390 
391 /* DG1 info */
392 static struct intel_vsec_header dg1_telemetry = {
393 	.length = 0x10,
394 	.id = 2,
395 	.num_entries = 1,
396 	.entry_size = 3,
397 	.tbir = 0,
398 	.offset = 0x466000,
399 };
400 
401 static struct intel_vsec_header *dg1_capabilities[] = {
402 	&dg1_telemetry,
403 	NULL
404 };
405 
406 static const struct intel_vsec_platform_info dg1_info = {
407 	.capabilities = dg1_capabilities,
408 	.quirks = VSEC_QUIRK_NO_DVSEC | VSEC_QUIRK_EARLY_HW,
409 };
410 
411 #define PCI_DEVICE_ID_INTEL_VSEC_ADL		0x467d
412 #define PCI_DEVICE_ID_INTEL_VSEC_DG1		0x490e
413 #define PCI_DEVICE_ID_INTEL_VSEC_OOBMSM		0x09a7
414 #define PCI_DEVICE_ID_INTEL_VSEC_RPL		0xa77d
415 #define PCI_DEVICE_ID_INTEL_VSEC_TGL		0x9a0d
416 static const struct pci_device_id intel_vsec_pci_ids[] = {
417 	{ PCI_DEVICE_DATA(INTEL, VSEC_ADL, &tgl_info) },
418 	{ PCI_DEVICE_DATA(INTEL, VSEC_DG1, &dg1_info) },
419 	{ PCI_DEVICE_DATA(INTEL, VSEC_OOBMSM, &(struct intel_vsec_platform_info) {}) },
420 	{ PCI_DEVICE_DATA(INTEL, VSEC_RPL, &tgl_info) },
421 	{ PCI_DEVICE_DATA(INTEL, VSEC_TGL, &tgl_info) },
422 	{ }
423 };
424 MODULE_DEVICE_TABLE(pci, intel_vsec_pci_ids);
425 
426 static pci_ers_result_t intel_vsec_pci_error_detected(struct pci_dev *pdev,
427 						      pci_channel_state_t state)
428 {
429 	pci_ers_result_t status = PCI_ERS_RESULT_NEED_RESET;
430 
431 	dev_info(&pdev->dev, "PCI error detected, state %d", state);
432 
433 	if (state == pci_channel_io_perm_failure)
434 		status = PCI_ERS_RESULT_DISCONNECT;
435 	else
436 		pci_disable_device(pdev);
437 
438 	return status;
439 }
440 
441 static pci_ers_result_t intel_vsec_pci_slot_reset(struct pci_dev *pdev)
442 {
443 	struct intel_vsec_device *intel_vsec_dev;
444 	pci_ers_result_t status = PCI_ERS_RESULT_DISCONNECT;
445 	const struct pci_device_id *pci_dev_id;
446 	unsigned long index;
447 
448 	dev_info(&pdev->dev, "Resetting PCI slot\n");
449 
450 	msleep(2000);
451 	if (pci_enable_device(pdev)) {
452 		dev_info(&pdev->dev,
453 			 "Failed to re-enable PCI device after reset.\n");
454 		goto out;
455 	}
456 
457 	status = PCI_ERS_RESULT_RECOVERED;
458 
459 	xa_for_each(&auxdev_array, index, intel_vsec_dev) {
460 		/* check if pdev doesn't match */
461 		if (pdev != intel_vsec_dev->pcidev)
462 			continue;
463 		devm_release_action(&pdev->dev, intel_vsec_remove_aux,
464 				    &intel_vsec_dev->auxdev);
465 	}
466 	pci_disable_device(pdev);
467 	pci_restore_state(pdev);
468 	pci_dev_id = pci_match_id(intel_vsec_pci_ids, pdev);
469 	intel_vsec_pci_probe(pdev, pci_dev_id);
470 
471 out:
472 	return status;
473 }
474 
475 static void intel_vsec_pci_resume(struct pci_dev *pdev)
476 {
477 	dev_info(&pdev->dev, "Done resuming PCI device\n");
478 }
479 
480 static const struct pci_error_handlers intel_vsec_pci_err_handlers = {
481 	.error_detected = intel_vsec_pci_error_detected,
482 	.slot_reset = intel_vsec_pci_slot_reset,
483 	.resume = intel_vsec_pci_resume,
484 };
485 
486 static struct pci_driver intel_vsec_pci_driver = {
487 	.name = "intel_vsec",
488 	.id_table = intel_vsec_pci_ids,
489 	.probe = intel_vsec_pci_probe,
490 	.err_handler = &intel_vsec_pci_err_handlers,
491 };
492 module_pci_driver(intel_vsec_pci_driver);
493 
494 MODULE_AUTHOR("David E. Box <david.e.box@linux.intel.com>");
495 MODULE_DESCRIPTION("Intel Extended Capabilities auxiliary bus driver");
496 MODULE_LICENSE("GPL v2");
497