1 // SPDX-License-Identifier: GPL-2.0-only
2 /* Copyright(c) 2020 Intel Corporation. */
3 #include <linux/io-64-nonatomic-lo-hi.h>
4 #include <linux/device.h>
5 #include <linux/slab.h>
6 #include <linux/pci.h>
7 #include <cxlmem.h>
8 #include <cxlpci.h>
9 #include <pmu.h>
10
11 #include "core.h"
12
13 /**
14 * DOC: cxl registers
15 *
16 * CXL device capabilities are enumerated by PCI DVSEC (Designated
17 * Vendor-specific) and / or descriptors provided by platform firmware.
18 * They can be defined as a set like the device and component registers
19 * mandated by CXL Section 8.1.12.2 Memory Device PCIe Capabilities and
20 * Extended Capabilities, or they can be individual capabilities
21 * appended to bridged and endpoint devices.
22 *
23 * Provide common infrastructure for enumerating and mapping these
24 * discrete capabilities.
25 */
26
27 /**
28 * cxl_probe_component_regs() - Detect CXL Component register blocks
29 * @dev: Host device of the @base mapping
30 * @base: Mapping containing the HDM Decoder Capability Header
31 * @map: Map object describing the register block information found
32 *
33 * See CXL 2.0 8.2.4 Component Register Layout and Definition
34 * See CXL 2.0 8.2.5.5 CXL Device Register Interface
35 *
36 * Probe for component register information and return it in map object.
37 */
cxl_probe_component_regs(struct device * dev,void __iomem * base,struct cxl_component_reg_map * map)38 void cxl_probe_component_regs(struct device *dev, void __iomem *base,
39 struct cxl_component_reg_map *map)
40 {
41 int cap, cap_count;
42 u32 cap_array;
43
44 *map = (struct cxl_component_reg_map) { 0 };
45
46 /*
47 * CXL.cache and CXL.mem registers are at offset 0x1000 as defined in
48 * CXL 2.0 8.2.4 Table 141.
49 */
50 base += CXL_CM_OFFSET;
51
52 cap_array = readl(base + CXL_CM_CAP_HDR_OFFSET);
53
54 if (FIELD_GET(CXL_CM_CAP_HDR_ID_MASK, cap_array) != CM_CAP_HDR_CAP_ID) {
55 dev_err(dev,
56 "Couldn't locate the CXL.cache and CXL.mem capability array header.\n");
57 return;
58 }
59
60 /* It's assumed that future versions will be backward compatible */
61 cap_count = FIELD_GET(CXL_CM_CAP_HDR_ARRAY_SIZE_MASK, cap_array);
62
63 for (cap = 1; cap <= cap_count; cap++) {
64 void __iomem *register_block;
65 struct cxl_reg_map *rmap;
66 u16 cap_id, offset;
67 u32 length, hdr;
68
69 hdr = readl(base + cap * 0x4);
70
71 cap_id = FIELD_GET(CXL_CM_CAP_HDR_ID_MASK, hdr);
72 offset = FIELD_GET(CXL_CM_CAP_PTR_MASK, hdr);
73 register_block = base + offset;
74 hdr = readl(register_block);
75
76 rmap = NULL;
77 switch (cap_id) {
78 case CXL_CM_CAP_CAP_ID_HDM: {
79 int decoder_cnt;
80
81 dev_dbg(dev, "found HDM decoder capability (0x%x)\n",
82 offset);
83
84 decoder_cnt = cxl_hdm_decoder_count(hdr);
85 length = 0x20 * decoder_cnt + 0x10;
86 rmap = &map->hdm_decoder;
87 break;
88 }
89 case CXL_CM_CAP_CAP_ID_RAS:
90 dev_dbg(dev, "found RAS capability (0x%x)\n",
91 offset);
92 length = CXL_RAS_CAPABILITY_LENGTH;
93 rmap = &map->ras;
94 break;
95 default:
96 dev_dbg(dev, "Unknown CM cap ID: %d (0x%x)\n", cap_id,
97 offset);
98 break;
99 }
100
101 if (!rmap)
102 continue;
103 rmap->valid = true;
104 rmap->id = cap_id;
105 rmap->offset = CXL_CM_OFFSET + offset;
106 rmap->size = length;
107 }
108 }
109 EXPORT_SYMBOL_NS_GPL(cxl_probe_component_regs, CXL);
110
111 /**
112 * cxl_probe_device_regs() - Detect CXL Device register blocks
113 * @dev: Host device of the @base mapping
114 * @base: Mapping of CXL 2.0 8.2.8 CXL Device Register Interface
115 * @map: Map object describing the register block information found
116 *
117 * Probe for device register information and return it in map object.
118 */
cxl_probe_device_regs(struct device * dev,void __iomem * base,struct cxl_device_reg_map * map)119 void cxl_probe_device_regs(struct device *dev, void __iomem *base,
120 struct cxl_device_reg_map *map)
121 {
122 int cap, cap_count;
123 u64 cap_array;
124
125 *map = (struct cxl_device_reg_map){ 0 };
126
127 cap_array = readq(base + CXLDEV_CAP_ARRAY_OFFSET);
128 if (FIELD_GET(CXLDEV_CAP_ARRAY_ID_MASK, cap_array) !=
129 CXLDEV_CAP_ARRAY_CAP_ID)
130 return;
131
132 cap_count = FIELD_GET(CXLDEV_CAP_ARRAY_COUNT_MASK, cap_array);
133
134 for (cap = 1; cap <= cap_count; cap++) {
135 struct cxl_reg_map *rmap;
136 u32 offset, length;
137 u16 cap_id;
138
139 cap_id = FIELD_GET(CXLDEV_CAP_HDR_CAP_ID_MASK,
140 readl(base + cap * 0x10));
141 offset = readl(base + cap * 0x10 + 0x4);
142 length = readl(base + cap * 0x10 + 0x8);
143
144 rmap = NULL;
145 switch (cap_id) {
146 case CXLDEV_CAP_CAP_ID_DEVICE_STATUS:
147 dev_dbg(dev, "found Status capability (0x%x)\n", offset);
148 rmap = &map->status;
149 break;
150 case CXLDEV_CAP_CAP_ID_PRIMARY_MAILBOX:
151 dev_dbg(dev, "found Mailbox capability (0x%x)\n", offset);
152 rmap = &map->mbox;
153 break;
154 case CXLDEV_CAP_CAP_ID_SECONDARY_MAILBOX:
155 dev_dbg(dev, "found Secondary Mailbox capability (0x%x)\n", offset);
156 break;
157 case CXLDEV_CAP_CAP_ID_MEMDEV:
158 dev_dbg(dev, "found Memory Device capability (0x%x)\n", offset);
159 rmap = &map->memdev;
160 break;
161 default:
162 if (cap_id >= 0x8000)
163 dev_dbg(dev, "Vendor cap ID: %#x offset: %#x\n", cap_id, offset);
164 else
165 dev_dbg(dev, "Unknown cap ID: %#x offset: %#x\n", cap_id, offset);
166 break;
167 }
168
169 if (!rmap)
170 continue;
171 rmap->valid = true;
172 rmap->id = cap_id;
173 rmap->offset = offset;
174 rmap->size = length;
175 }
176 }
177 EXPORT_SYMBOL_NS_GPL(cxl_probe_device_regs, CXL);
178
devm_cxl_iomap_block(struct device * dev,resource_size_t addr,resource_size_t length)179 void __iomem *devm_cxl_iomap_block(struct device *dev, resource_size_t addr,
180 resource_size_t length)
181 {
182 void __iomem *ret_val;
183 struct resource *res;
184
185 if (WARN_ON_ONCE(addr == CXL_RESOURCE_NONE))
186 return NULL;
187
188 res = devm_request_mem_region(dev, addr, length, dev_name(dev));
189 if (!res) {
190 resource_size_t end = addr + length - 1;
191
192 dev_err(dev, "Failed to request region %pa-%pa\n", &addr, &end);
193 return NULL;
194 }
195
196 ret_val = devm_ioremap(dev, addr, length);
197 if (!ret_val)
198 dev_err(dev, "Failed to map region %pr\n", res);
199
200 return ret_val;
201 }
202
cxl_map_component_regs(const struct cxl_register_map * map,struct cxl_component_regs * regs,unsigned long map_mask)203 int cxl_map_component_regs(const struct cxl_register_map *map,
204 struct cxl_component_regs *regs,
205 unsigned long map_mask)
206 {
207 struct device *host = map->host;
208 struct mapinfo {
209 const struct cxl_reg_map *rmap;
210 void __iomem **addr;
211 } mapinfo[] = {
212 { &map->component_map.hdm_decoder, ®s->hdm_decoder },
213 { &map->component_map.ras, ®s->ras },
214 };
215 int i;
216
217 for (i = 0; i < ARRAY_SIZE(mapinfo); i++) {
218 struct mapinfo *mi = &mapinfo[i];
219 resource_size_t addr;
220 resource_size_t length;
221
222 if (!mi->rmap->valid)
223 continue;
224 if (!test_bit(mi->rmap->id, &map_mask))
225 continue;
226 addr = map->resource + mi->rmap->offset;
227 length = mi->rmap->size;
228 *(mi->addr) = devm_cxl_iomap_block(host, addr, length);
229 if (!*(mi->addr))
230 return -ENOMEM;
231 }
232
233 return 0;
234 }
235 EXPORT_SYMBOL_NS_GPL(cxl_map_component_regs, CXL);
236
cxl_map_device_regs(const struct cxl_register_map * map,struct cxl_device_regs * regs)237 int cxl_map_device_regs(const struct cxl_register_map *map,
238 struct cxl_device_regs *regs)
239 {
240 struct device *host = map->host;
241 resource_size_t phys_addr = map->resource;
242 struct mapinfo {
243 const struct cxl_reg_map *rmap;
244 void __iomem **addr;
245 } mapinfo[] = {
246 { &map->device_map.status, ®s->status, },
247 { &map->device_map.mbox, ®s->mbox, },
248 { &map->device_map.memdev, ®s->memdev, },
249 };
250 int i;
251
252 for (i = 0; i < ARRAY_SIZE(mapinfo); i++) {
253 struct mapinfo *mi = &mapinfo[i];
254 resource_size_t length;
255 resource_size_t addr;
256
257 if (!mi->rmap->valid)
258 continue;
259
260 addr = phys_addr + mi->rmap->offset;
261 length = mi->rmap->size;
262 *(mi->addr) = devm_cxl_iomap_block(host, addr, length);
263 if (!*(mi->addr))
264 return -ENOMEM;
265 }
266
267 return 0;
268 }
269 EXPORT_SYMBOL_NS_GPL(cxl_map_device_regs, CXL);
270
cxl_decode_regblock(struct pci_dev * pdev,u32 reg_lo,u32 reg_hi,struct cxl_register_map * map)271 static bool cxl_decode_regblock(struct pci_dev *pdev, u32 reg_lo, u32 reg_hi,
272 struct cxl_register_map *map)
273 {
274 int bar = FIELD_GET(CXL_DVSEC_REG_LOCATOR_BIR_MASK, reg_lo);
275 u64 offset = ((u64)reg_hi << 32) |
276 (reg_lo & CXL_DVSEC_REG_LOCATOR_BLOCK_OFF_LOW_MASK);
277
278 if (offset > pci_resource_len(pdev, bar)) {
279 dev_warn(&pdev->dev,
280 "BAR%d: %pr: too small (offset: %pa, type: %d)\n", bar,
281 &pdev->resource[bar], &offset, map->reg_type);
282 return false;
283 }
284
285 map->reg_type = FIELD_GET(CXL_DVSEC_REG_LOCATOR_BLOCK_ID_MASK, reg_lo);
286 map->resource = pci_resource_start(pdev, bar) + offset;
287 map->max_size = pci_resource_len(pdev, bar) - offset;
288 return true;
289 }
290
291 /**
292 * cxl_find_regblock_instance() - Locate a register block by type / index
293 * @pdev: The CXL PCI device to enumerate.
294 * @type: Register Block Indicator id
295 * @map: Enumeration output, clobbered on error
296 * @index: Index into which particular instance of a regblock wanted in the
297 * order found in register locator DVSEC.
298 *
299 * Return: 0 if register block enumerated, negative error code otherwise
300 *
301 * A CXL DVSEC may point to one or more register blocks, search for them
302 * by @type and @index.
303 */
cxl_find_regblock_instance(struct pci_dev * pdev,enum cxl_regloc_type type,struct cxl_register_map * map,int index)304 int cxl_find_regblock_instance(struct pci_dev *pdev, enum cxl_regloc_type type,
305 struct cxl_register_map *map, int index)
306 {
307 u32 regloc_size, regblocks;
308 int instance = 0;
309 int regloc, i;
310
311 *map = (struct cxl_register_map) {
312 .host = &pdev->dev,
313 .resource = CXL_RESOURCE_NONE,
314 };
315
316 regloc = pci_find_dvsec_capability(pdev, PCI_DVSEC_VENDOR_ID_CXL,
317 CXL_DVSEC_REG_LOCATOR);
318 if (!regloc)
319 return -ENXIO;
320
321 pci_read_config_dword(pdev, regloc + PCI_DVSEC_HEADER1, ®loc_size);
322 regloc_size = FIELD_GET(PCI_DVSEC_HEADER1_LENGTH_MASK, regloc_size);
323
324 regloc += CXL_DVSEC_REG_LOCATOR_BLOCK1_OFFSET;
325 regblocks = (regloc_size - CXL_DVSEC_REG_LOCATOR_BLOCK1_OFFSET) / 8;
326
327 for (i = 0; i < regblocks; i++, regloc += 8) {
328 u32 reg_lo, reg_hi;
329
330 pci_read_config_dword(pdev, regloc, ®_lo);
331 pci_read_config_dword(pdev, regloc + 4, ®_hi);
332
333 if (!cxl_decode_regblock(pdev, reg_lo, reg_hi, map))
334 continue;
335
336 if (map->reg_type == type) {
337 if (index == instance)
338 return 0;
339 instance++;
340 }
341 }
342
343 map->resource = CXL_RESOURCE_NONE;
344 return -ENODEV;
345 }
346 EXPORT_SYMBOL_NS_GPL(cxl_find_regblock_instance, CXL);
347
348 /**
349 * cxl_find_regblock() - Locate register blocks by type
350 * @pdev: The CXL PCI device to enumerate.
351 * @type: Register Block Indicator id
352 * @map: Enumeration output, clobbered on error
353 *
354 * Return: 0 if register block enumerated, negative error code otherwise
355 *
356 * A CXL DVSEC may point to one or more register blocks, search for them
357 * by @type.
358 */
cxl_find_regblock(struct pci_dev * pdev,enum cxl_regloc_type type,struct cxl_register_map * map)359 int cxl_find_regblock(struct pci_dev *pdev, enum cxl_regloc_type type,
360 struct cxl_register_map *map)
361 {
362 return cxl_find_regblock_instance(pdev, type, map, 0);
363 }
364 EXPORT_SYMBOL_NS_GPL(cxl_find_regblock, CXL);
365
366 /**
367 * cxl_count_regblock() - Count instances of a given regblock type.
368 * @pdev: The CXL PCI device to enumerate.
369 * @type: Register Block Indicator id
370 *
371 * Some regblocks may be repeated. Count how many instances.
372 *
373 * Return: count of matching regblocks.
374 */
cxl_count_regblock(struct pci_dev * pdev,enum cxl_regloc_type type)375 int cxl_count_regblock(struct pci_dev *pdev, enum cxl_regloc_type type)
376 {
377 struct cxl_register_map map;
378 int rc, count = 0;
379
380 while (1) {
381 rc = cxl_find_regblock_instance(pdev, type, &map, count);
382 if (rc)
383 return count;
384 count++;
385 }
386 }
387 EXPORT_SYMBOL_NS_GPL(cxl_count_regblock, CXL);
388
cxl_map_pmu_regs(struct cxl_register_map * map,struct cxl_pmu_regs * regs)389 int cxl_map_pmu_regs(struct cxl_register_map *map, struct cxl_pmu_regs *regs)
390 {
391 struct device *dev = map->host;
392 resource_size_t phys_addr;
393
394 phys_addr = map->resource;
395 regs->pmu = devm_cxl_iomap_block(dev, phys_addr, CXL_PMU_REGMAP_SIZE);
396 if (!regs->pmu)
397 return -ENOMEM;
398
399 return 0;
400 }
401 EXPORT_SYMBOL_NS_GPL(cxl_map_pmu_regs, CXL);
402
cxl_map_regblock(struct cxl_register_map * map)403 static int cxl_map_regblock(struct cxl_register_map *map)
404 {
405 struct device *host = map->host;
406
407 map->base = ioremap(map->resource, map->max_size);
408 if (!map->base) {
409 dev_err(host, "failed to map registers\n");
410 return -ENOMEM;
411 }
412
413 dev_dbg(host, "Mapped CXL Memory Device resource %pa\n", &map->resource);
414 return 0;
415 }
416
cxl_unmap_regblock(struct cxl_register_map * map)417 static void cxl_unmap_regblock(struct cxl_register_map *map)
418 {
419 iounmap(map->base);
420 map->base = NULL;
421 }
422
cxl_probe_regs(struct cxl_register_map * map)423 static int cxl_probe_regs(struct cxl_register_map *map)
424 {
425 struct cxl_component_reg_map *comp_map;
426 struct cxl_device_reg_map *dev_map;
427 struct device *host = map->host;
428 void __iomem *base = map->base;
429
430 switch (map->reg_type) {
431 case CXL_REGLOC_RBI_COMPONENT:
432 comp_map = &map->component_map;
433 cxl_probe_component_regs(host, base, comp_map);
434 dev_dbg(host, "Set up component registers\n");
435 break;
436 case CXL_REGLOC_RBI_MEMDEV:
437 dev_map = &map->device_map;
438 cxl_probe_device_regs(host, base, dev_map);
439 if (!dev_map->status.valid || !dev_map->mbox.valid ||
440 !dev_map->memdev.valid) {
441 dev_err(host, "registers not found: %s%s%s\n",
442 !dev_map->status.valid ? "status " : "",
443 !dev_map->mbox.valid ? "mbox " : "",
444 !dev_map->memdev.valid ? "memdev " : "");
445 return -ENXIO;
446 }
447
448 dev_dbg(host, "Probing device registers...\n");
449 break;
450 default:
451 break;
452 }
453
454 return 0;
455 }
456
cxl_setup_regs(struct cxl_register_map * map)457 int cxl_setup_regs(struct cxl_register_map *map)
458 {
459 int rc;
460
461 rc = cxl_map_regblock(map);
462 if (rc)
463 return rc;
464
465 rc = cxl_probe_regs(map);
466 cxl_unmap_regblock(map);
467
468 return rc;
469 }
470 EXPORT_SYMBOL_NS_GPL(cxl_setup_regs, CXL);
471
cxl_rcrb_to_aer(struct device * dev,resource_size_t rcrb)472 u16 cxl_rcrb_to_aer(struct device *dev, resource_size_t rcrb)
473 {
474 void __iomem *addr;
475 u16 offset = 0;
476 u32 cap_hdr;
477
478 if (WARN_ON_ONCE(rcrb == CXL_RESOURCE_NONE))
479 return 0;
480
481 if (!request_mem_region(rcrb, SZ_4K, dev_name(dev)))
482 return 0;
483
484 addr = ioremap(rcrb, SZ_4K);
485 if (!addr)
486 goto out;
487
488 cap_hdr = readl(addr + offset);
489 while (PCI_EXT_CAP_ID(cap_hdr) != PCI_EXT_CAP_ID_ERR) {
490 offset = PCI_EXT_CAP_NEXT(cap_hdr);
491
492 /* Offset 0 terminates capability list. */
493 if (!offset)
494 break;
495 cap_hdr = readl(addr + offset);
496 }
497
498 if (offset)
499 dev_dbg(dev, "found AER extended capability (0x%x)\n", offset);
500
501 iounmap(addr);
502 out:
503 release_mem_region(rcrb, SZ_4K);
504
505 return offset;
506 }
507
__rcrb_to_component(struct device * dev,struct cxl_rcrb_info * ri,enum cxl_rcrb which)508 resource_size_t __rcrb_to_component(struct device *dev, struct cxl_rcrb_info *ri,
509 enum cxl_rcrb which)
510 {
511 resource_size_t component_reg_phys;
512 resource_size_t rcrb = ri->base;
513 void __iomem *addr;
514 u32 bar0, bar1;
515 u16 cmd;
516 u32 id;
517
518 if (which == CXL_RCRB_UPSTREAM)
519 rcrb += SZ_4K;
520
521 /*
522 * RCRB's BAR[0..1] point to component block containing CXL
523 * subsystem component registers. MEMBAR extraction follows
524 * the PCI Base spec here, esp. 64 bit extraction and memory
525 * ranges alignment (6.0, 7.5.1.2.1).
526 */
527 if (!request_mem_region(rcrb, SZ_4K, "CXL RCRB"))
528 return CXL_RESOURCE_NONE;
529 addr = ioremap(rcrb, SZ_4K);
530 if (!addr) {
531 dev_err(dev, "Failed to map region %pr\n", addr);
532 release_mem_region(rcrb, SZ_4K);
533 return CXL_RESOURCE_NONE;
534 }
535
536 id = readl(addr + PCI_VENDOR_ID);
537 cmd = readw(addr + PCI_COMMAND);
538 bar0 = readl(addr + PCI_BASE_ADDRESS_0);
539 bar1 = readl(addr + PCI_BASE_ADDRESS_1);
540 iounmap(addr);
541 release_mem_region(rcrb, SZ_4K);
542
543 /*
544 * Sanity check, see CXL 3.0 Figure 9-8 CXL Device that Does Not
545 * Remap Upstream Port and Component Registers
546 */
547 if (id == U32_MAX) {
548 if (which == CXL_RCRB_DOWNSTREAM)
549 dev_err(dev, "Failed to access Downstream Port RCRB\n");
550 return CXL_RESOURCE_NONE;
551 }
552 if (!(cmd & PCI_COMMAND_MEMORY))
553 return CXL_RESOURCE_NONE;
554 /* The RCRB is a Memory Window, and the MEM_TYPE_1M bit is obsolete */
555 if (bar0 & (PCI_BASE_ADDRESS_MEM_TYPE_1M | PCI_BASE_ADDRESS_SPACE_IO))
556 return CXL_RESOURCE_NONE;
557
558 component_reg_phys = bar0 & PCI_BASE_ADDRESS_MEM_MASK;
559 if (bar0 & PCI_BASE_ADDRESS_MEM_TYPE_64)
560 component_reg_phys |= ((u64)bar1) << 32;
561
562 if (!component_reg_phys)
563 return CXL_RESOURCE_NONE;
564
565 /* MEMBAR is block size (64k) aligned. */
566 if (!IS_ALIGNED(component_reg_phys, CXL_COMPONENT_REG_BLOCK_SIZE))
567 return CXL_RESOURCE_NONE;
568
569 return component_reg_phys;
570 }
571
cxl_rcd_component_reg_phys(struct device * dev,struct cxl_dport * dport)572 resource_size_t cxl_rcd_component_reg_phys(struct device *dev,
573 struct cxl_dport *dport)
574 {
575 if (!dport->rch)
576 return CXL_RESOURCE_NONE;
577 return __rcrb_to_component(dev, &dport->rcrb, CXL_RCRB_UPSTREAM);
578 }
579 EXPORT_SYMBOL_NS_GPL(cxl_rcd_component_reg_phys, CXL);
580