xref: /linux/drivers/cxl/core/hdm.c (revision b4db9f840283caca0d904436f187ef56a9126eaa)
1 // SPDX-License-Identifier: GPL-2.0-only
2 /* Copyright(c) 2022 Intel Corporation. All rights reserved. */
3 #include <linux/seq_file.h>
4 #include <linux/device.h>
5 #include <linux/delay.h>
6 
7 #include "cxlmem.h"
8 #include "core.h"
9 
10 /**
11  * DOC: cxl core hdm
12  *
13  * Compute Express Link Host Managed Device Memory, starting with the
14  * CXL 2.0 specification, is managed by an array of HDM Decoder register
15  * instances per CXL port and per CXL endpoint. Define common helpers
16  * for enumerating these registers and capabilities.
17  */
18 
19 DECLARE_RWSEM(cxl_dpa_rwsem);
20 
21 static int add_hdm_decoder(struct cxl_port *port, struct cxl_decoder *cxld,
22 			   int *target_map)
23 {
24 	int rc;
25 
26 	rc = cxl_decoder_add_locked(cxld, target_map);
27 	if (rc) {
28 		put_device(&cxld->dev);
29 		dev_err(&port->dev, "Failed to add decoder\n");
30 		return rc;
31 	}
32 
33 	rc = cxl_decoder_autoremove(&port->dev, cxld);
34 	if (rc)
35 		return rc;
36 
37 	dev_dbg(&cxld->dev, "Added to port %s\n", dev_name(&port->dev));
38 
39 	return 0;
40 }
41 
42 /*
43  * Per the CXL specification (8.2.5.12 CXL HDM Decoder Capability Structure)
44  * single ported host-bridges need not publish a decoder capability when a
45  * passthrough decode can be assumed, i.e. all transactions that the uport sees
46  * are claimed and passed to the single dport. Disable the range until the first
47  * CXL region is enumerated / activated.
48  */
49 int devm_cxl_add_passthrough_decoder(struct cxl_port *port)
50 {
51 	struct cxl_switch_decoder *cxlsd;
52 	struct cxl_dport *dport = NULL;
53 	int single_port_map[1];
54 	unsigned long index;
55 
56 	cxlsd = cxl_switch_decoder_alloc(port, 1);
57 	if (IS_ERR(cxlsd))
58 		return PTR_ERR(cxlsd);
59 
60 	device_lock_assert(&port->dev);
61 
62 	xa_for_each(&port->dports, index, dport)
63 		break;
64 	single_port_map[0] = dport->port_id;
65 
66 	return add_hdm_decoder(port, &cxlsd->cxld, single_port_map);
67 }
68 EXPORT_SYMBOL_NS_GPL(devm_cxl_add_passthrough_decoder, CXL);
69 
70 static void parse_hdm_decoder_caps(struct cxl_hdm *cxlhdm)
71 {
72 	u32 hdm_cap;
73 
74 	hdm_cap = readl(cxlhdm->regs.hdm_decoder + CXL_HDM_DECODER_CAP_OFFSET);
75 	cxlhdm->decoder_count = cxl_hdm_decoder_count(hdm_cap);
76 	cxlhdm->target_count =
77 		FIELD_GET(CXL_HDM_DECODER_TARGET_COUNT_MASK, hdm_cap);
78 	if (FIELD_GET(CXL_HDM_DECODER_INTERLEAVE_11_8, hdm_cap))
79 		cxlhdm->interleave_mask |= GENMASK(11, 8);
80 	if (FIELD_GET(CXL_HDM_DECODER_INTERLEAVE_14_12, hdm_cap))
81 		cxlhdm->interleave_mask |= GENMASK(14, 12);
82 }
83 
84 static bool should_emulate_decoders(struct cxl_endpoint_dvsec_info *info)
85 {
86 	struct cxl_hdm *cxlhdm;
87 	void __iomem *hdm;
88 	u32 ctrl;
89 	int i;
90 
91 	if (!info)
92 		return false;
93 
94 	cxlhdm = dev_get_drvdata(&info->port->dev);
95 	hdm = cxlhdm->regs.hdm_decoder;
96 
97 	if (!hdm)
98 		return true;
99 
100 	/*
101 	 * If HDM decoders are present and the driver is in control of
102 	 * Mem_Enable skip DVSEC based emulation
103 	 */
104 	if (!info->mem_enabled)
105 		return false;
106 
107 	/*
108 	 * If any decoders are committed already, there should not be any
109 	 * emulated DVSEC decoders.
110 	 */
111 	for (i = 0; i < cxlhdm->decoder_count; i++) {
112 		ctrl = readl(hdm + CXL_HDM_DECODER0_CTRL_OFFSET(i));
113 		dev_dbg(&info->port->dev,
114 			"decoder%d.%d: committed: %ld base: %#x_%.8x size: %#x_%.8x\n",
115 			info->port->id, i,
116 			FIELD_GET(CXL_HDM_DECODER0_CTRL_COMMITTED, ctrl),
117 			readl(hdm + CXL_HDM_DECODER0_BASE_HIGH_OFFSET(i)),
118 			readl(hdm + CXL_HDM_DECODER0_BASE_LOW_OFFSET(i)),
119 			readl(hdm + CXL_HDM_DECODER0_SIZE_HIGH_OFFSET(i)),
120 			readl(hdm + CXL_HDM_DECODER0_SIZE_LOW_OFFSET(i)));
121 		if (FIELD_GET(CXL_HDM_DECODER0_CTRL_COMMITTED, ctrl))
122 			return false;
123 	}
124 
125 	return true;
126 }
127 
128 /**
129  * devm_cxl_setup_hdm - map HDM decoder component registers
130  * @port: cxl_port to map
131  * @info: cached DVSEC range register info
132  */
133 struct cxl_hdm *devm_cxl_setup_hdm(struct cxl_port *port,
134 				   struct cxl_endpoint_dvsec_info *info)
135 {
136 	struct cxl_register_map *reg_map = &port->reg_map;
137 	struct device *dev = &port->dev;
138 	struct cxl_hdm *cxlhdm;
139 	int rc;
140 
141 	cxlhdm = devm_kzalloc(dev, sizeof(*cxlhdm), GFP_KERNEL);
142 	if (!cxlhdm)
143 		return ERR_PTR(-ENOMEM);
144 	cxlhdm->port = port;
145 	dev_set_drvdata(dev, cxlhdm);
146 
147 	/* Memory devices can configure device HDM using DVSEC range regs. */
148 	if (reg_map->resource == CXL_RESOURCE_NONE) {
149 		if (!info || !info->mem_enabled) {
150 			dev_err(dev, "No component registers mapped\n");
151 			return ERR_PTR(-ENXIO);
152 		}
153 
154 		cxlhdm->decoder_count = info->ranges;
155 		return cxlhdm;
156 	}
157 
158 	if (!reg_map->component_map.hdm_decoder.valid) {
159 		dev_dbg(&port->dev, "HDM decoder registers not implemented\n");
160 		/* unique error code to indicate no HDM decoder capability */
161 		return ERR_PTR(-ENODEV);
162 	}
163 
164 	rc = cxl_map_component_regs(reg_map, &cxlhdm->regs,
165 				    BIT(CXL_CM_CAP_CAP_ID_HDM));
166 	if (rc) {
167 		dev_err(dev, "Failed to map HDM capability.\n");
168 		return ERR_PTR(rc);
169 	}
170 
171 	parse_hdm_decoder_caps(cxlhdm);
172 	if (cxlhdm->decoder_count == 0) {
173 		dev_err(dev, "Spec violation. Caps invalid\n");
174 		return ERR_PTR(-ENXIO);
175 	}
176 
177 	/*
178 	 * Now that the hdm capability is parsed, decide if range
179 	 * register emulation is needed and fixup cxlhdm accordingly.
180 	 */
181 	if (should_emulate_decoders(info)) {
182 		dev_dbg(dev, "Fallback map %d range register%s\n", info->ranges,
183 			info->ranges > 1 ? "s" : "");
184 		cxlhdm->decoder_count = info->ranges;
185 	}
186 
187 	return cxlhdm;
188 }
189 EXPORT_SYMBOL_NS_GPL(devm_cxl_setup_hdm, CXL);
190 
191 static void __cxl_dpa_debug(struct seq_file *file, struct resource *r, int depth)
192 {
193 	unsigned long long start = r->start, end = r->end;
194 
195 	seq_printf(file, "%*s%08llx-%08llx : %s\n", depth * 2, "", start, end,
196 		   r->name);
197 }
198 
199 void cxl_dpa_debug(struct seq_file *file, struct cxl_dev_state *cxlds)
200 {
201 	struct resource *p1, *p2;
202 
203 	down_read(&cxl_dpa_rwsem);
204 	for (p1 = cxlds->dpa_res.child; p1; p1 = p1->sibling) {
205 		__cxl_dpa_debug(file, p1, 0);
206 		for (p2 = p1->child; p2; p2 = p2->sibling)
207 			__cxl_dpa_debug(file, p2, 1);
208 	}
209 	up_read(&cxl_dpa_rwsem);
210 }
211 EXPORT_SYMBOL_NS_GPL(cxl_dpa_debug, CXL);
212 
213 /*
214  * Must be called in a context that synchronizes against this decoder's
215  * port ->remove() callback (like an endpoint decoder sysfs attribute)
216  */
217 static void __cxl_dpa_release(struct cxl_endpoint_decoder *cxled)
218 {
219 	struct cxl_memdev *cxlmd = cxled_to_memdev(cxled);
220 	struct cxl_port *port = cxled_to_port(cxled);
221 	struct cxl_dev_state *cxlds = cxlmd->cxlds;
222 	struct resource *res = cxled->dpa_res;
223 	resource_size_t skip_start;
224 
225 	lockdep_assert_held_write(&cxl_dpa_rwsem);
226 
227 	/* save @skip_start, before @res is released */
228 	skip_start = res->start - cxled->skip;
229 	__release_region(&cxlds->dpa_res, res->start, resource_size(res));
230 	if (cxled->skip)
231 		__release_region(&cxlds->dpa_res, skip_start, cxled->skip);
232 	cxled->skip = 0;
233 	cxled->dpa_res = NULL;
234 	put_device(&cxled->cxld.dev);
235 	port->hdm_end--;
236 }
237 
238 static void cxl_dpa_release(void *cxled)
239 {
240 	down_write(&cxl_dpa_rwsem);
241 	__cxl_dpa_release(cxled);
242 	up_write(&cxl_dpa_rwsem);
243 }
244 
245 /*
246  * Must be called from context that will not race port device
247  * unregistration, like decoder sysfs attribute methods
248  */
249 static void devm_cxl_dpa_release(struct cxl_endpoint_decoder *cxled)
250 {
251 	struct cxl_port *port = cxled_to_port(cxled);
252 
253 	lockdep_assert_held_write(&cxl_dpa_rwsem);
254 	devm_remove_action(&port->dev, cxl_dpa_release, cxled);
255 	__cxl_dpa_release(cxled);
256 }
257 
258 static int __cxl_dpa_reserve(struct cxl_endpoint_decoder *cxled,
259 			     resource_size_t base, resource_size_t len,
260 			     resource_size_t skipped)
261 {
262 	struct cxl_memdev *cxlmd = cxled_to_memdev(cxled);
263 	struct cxl_port *port = cxled_to_port(cxled);
264 	struct cxl_dev_state *cxlds = cxlmd->cxlds;
265 	struct device *dev = &port->dev;
266 	struct resource *res;
267 
268 	lockdep_assert_held_write(&cxl_dpa_rwsem);
269 
270 	if (!len) {
271 		dev_warn(dev, "decoder%d.%d: empty reservation attempted\n",
272 			 port->id, cxled->cxld.id);
273 		return -EINVAL;
274 	}
275 
276 	if (cxled->dpa_res) {
277 		dev_dbg(dev, "decoder%d.%d: existing allocation %pr assigned\n",
278 			port->id, cxled->cxld.id, cxled->dpa_res);
279 		return -EBUSY;
280 	}
281 
282 	if (port->hdm_end + 1 != cxled->cxld.id) {
283 		/*
284 		 * Assumes alloc and commit order is always in hardware instance
285 		 * order per expectations from 8.2.5.12.20 Committing Decoder
286 		 * Programming that enforce decoder[m] committed before
287 		 * decoder[m+1] commit start.
288 		 */
289 		dev_dbg(dev, "decoder%d.%d: expected decoder%d.%d\n", port->id,
290 			cxled->cxld.id, port->id, port->hdm_end + 1);
291 		return -EBUSY;
292 	}
293 
294 	if (skipped) {
295 		res = __request_region(&cxlds->dpa_res, base - skipped, skipped,
296 				       dev_name(&cxled->cxld.dev), 0);
297 		if (!res) {
298 			dev_dbg(dev,
299 				"decoder%d.%d: failed to reserve skipped space\n",
300 				port->id, cxled->cxld.id);
301 			return -EBUSY;
302 		}
303 	}
304 	res = __request_region(&cxlds->dpa_res, base, len,
305 			       dev_name(&cxled->cxld.dev), 0);
306 	if (!res) {
307 		dev_dbg(dev, "decoder%d.%d: failed to reserve allocation\n",
308 			port->id, cxled->cxld.id);
309 		if (skipped)
310 			__release_region(&cxlds->dpa_res, base - skipped,
311 					 skipped);
312 		return -EBUSY;
313 	}
314 	cxled->dpa_res = res;
315 	cxled->skip = skipped;
316 
317 	if (resource_contains(&cxlds->pmem_res, res))
318 		cxled->mode = CXL_DECODER_PMEM;
319 	else if (resource_contains(&cxlds->ram_res, res))
320 		cxled->mode = CXL_DECODER_RAM;
321 	else {
322 		dev_dbg(dev, "decoder%d.%d: %pr mixed\n", port->id,
323 			cxled->cxld.id, cxled->dpa_res);
324 		cxled->mode = CXL_DECODER_MIXED;
325 	}
326 
327 	port->hdm_end++;
328 	get_device(&cxled->cxld.dev);
329 	return 0;
330 }
331 
332 int devm_cxl_dpa_reserve(struct cxl_endpoint_decoder *cxled,
333 				resource_size_t base, resource_size_t len,
334 				resource_size_t skipped)
335 {
336 	struct cxl_port *port = cxled_to_port(cxled);
337 	int rc;
338 
339 	down_write(&cxl_dpa_rwsem);
340 	rc = __cxl_dpa_reserve(cxled, base, len, skipped);
341 	up_write(&cxl_dpa_rwsem);
342 
343 	if (rc)
344 		return rc;
345 
346 	return devm_add_action_or_reset(&port->dev, cxl_dpa_release, cxled);
347 }
348 EXPORT_SYMBOL_NS_GPL(devm_cxl_dpa_reserve, CXL);
349 
350 resource_size_t cxl_dpa_size(struct cxl_endpoint_decoder *cxled)
351 {
352 	resource_size_t size = 0;
353 
354 	down_read(&cxl_dpa_rwsem);
355 	if (cxled->dpa_res)
356 		size = resource_size(cxled->dpa_res);
357 	up_read(&cxl_dpa_rwsem);
358 
359 	return size;
360 }
361 
362 resource_size_t cxl_dpa_resource_start(struct cxl_endpoint_decoder *cxled)
363 {
364 	resource_size_t base = -1;
365 
366 	lockdep_assert_held(&cxl_dpa_rwsem);
367 	if (cxled->dpa_res)
368 		base = cxled->dpa_res->start;
369 
370 	return base;
371 }
372 
373 int cxl_dpa_free(struct cxl_endpoint_decoder *cxled)
374 {
375 	struct cxl_port *port = cxled_to_port(cxled);
376 	struct device *dev = &cxled->cxld.dev;
377 	int rc;
378 
379 	down_write(&cxl_dpa_rwsem);
380 	if (!cxled->dpa_res) {
381 		rc = 0;
382 		goto out;
383 	}
384 	if (cxled->cxld.region) {
385 		dev_dbg(dev, "decoder assigned to: %s\n",
386 			dev_name(&cxled->cxld.region->dev));
387 		rc = -EBUSY;
388 		goto out;
389 	}
390 	if (cxled->cxld.flags & CXL_DECODER_F_ENABLE) {
391 		dev_dbg(dev, "decoder enabled\n");
392 		rc = -EBUSY;
393 		goto out;
394 	}
395 	if (cxled->cxld.id != port->hdm_end) {
396 		dev_dbg(dev, "expected decoder%d.%d\n", port->id,
397 			port->hdm_end);
398 		rc = -EBUSY;
399 		goto out;
400 	}
401 	devm_cxl_dpa_release(cxled);
402 	rc = 0;
403 out:
404 	up_write(&cxl_dpa_rwsem);
405 	return rc;
406 }
407 
408 int cxl_dpa_set_mode(struct cxl_endpoint_decoder *cxled,
409 		     enum cxl_decoder_mode mode)
410 {
411 	struct cxl_memdev *cxlmd = cxled_to_memdev(cxled);
412 	struct cxl_dev_state *cxlds = cxlmd->cxlds;
413 	struct device *dev = &cxled->cxld.dev;
414 	int rc;
415 
416 	switch (mode) {
417 	case CXL_DECODER_RAM:
418 	case CXL_DECODER_PMEM:
419 		break;
420 	default:
421 		dev_dbg(dev, "unsupported mode: %d\n", mode);
422 		return -EINVAL;
423 	}
424 
425 	down_write(&cxl_dpa_rwsem);
426 	if (cxled->cxld.flags & CXL_DECODER_F_ENABLE) {
427 		rc = -EBUSY;
428 		goto out;
429 	}
430 
431 	/*
432 	 * Only allow modes that are supported by the current partition
433 	 * configuration
434 	 */
435 	if (mode == CXL_DECODER_PMEM && !resource_size(&cxlds->pmem_res)) {
436 		dev_dbg(dev, "no available pmem capacity\n");
437 		rc = -ENXIO;
438 		goto out;
439 	}
440 	if (mode == CXL_DECODER_RAM && !resource_size(&cxlds->ram_res)) {
441 		dev_dbg(dev, "no available ram capacity\n");
442 		rc = -ENXIO;
443 		goto out;
444 	}
445 
446 	cxled->mode = mode;
447 	rc = 0;
448 out:
449 	up_write(&cxl_dpa_rwsem);
450 
451 	return rc;
452 }
453 
454 int cxl_dpa_alloc(struct cxl_endpoint_decoder *cxled, unsigned long long size)
455 {
456 	struct cxl_memdev *cxlmd = cxled_to_memdev(cxled);
457 	resource_size_t free_ram_start, free_pmem_start;
458 	struct cxl_port *port = cxled_to_port(cxled);
459 	struct cxl_dev_state *cxlds = cxlmd->cxlds;
460 	struct device *dev = &cxled->cxld.dev;
461 	resource_size_t start, avail, skip;
462 	struct resource *p, *last;
463 	int rc;
464 
465 	down_write(&cxl_dpa_rwsem);
466 	if (cxled->cxld.region) {
467 		dev_dbg(dev, "decoder attached to %s\n",
468 			dev_name(&cxled->cxld.region->dev));
469 		rc = -EBUSY;
470 		goto out;
471 	}
472 
473 	if (cxled->cxld.flags & CXL_DECODER_F_ENABLE) {
474 		dev_dbg(dev, "decoder enabled\n");
475 		rc = -EBUSY;
476 		goto out;
477 	}
478 
479 	for (p = cxlds->ram_res.child, last = NULL; p; p = p->sibling)
480 		last = p;
481 	if (last)
482 		free_ram_start = last->end + 1;
483 	else
484 		free_ram_start = cxlds->ram_res.start;
485 
486 	for (p = cxlds->pmem_res.child, last = NULL; p; p = p->sibling)
487 		last = p;
488 	if (last)
489 		free_pmem_start = last->end + 1;
490 	else
491 		free_pmem_start = cxlds->pmem_res.start;
492 
493 	if (cxled->mode == CXL_DECODER_RAM) {
494 		start = free_ram_start;
495 		avail = cxlds->ram_res.end - start + 1;
496 		skip = 0;
497 	} else if (cxled->mode == CXL_DECODER_PMEM) {
498 		resource_size_t skip_start, skip_end;
499 
500 		start = free_pmem_start;
501 		avail = cxlds->pmem_res.end - start + 1;
502 		skip_start = free_ram_start;
503 
504 		/*
505 		 * If some pmem is already allocated, then that allocation
506 		 * already handled the skip.
507 		 */
508 		if (cxlds->pmem_res.child &&
509 		    skip_start == cxlds->pmem_res.child->start)
510 			skip_end = skip_start - 1;
511 		else
512 			skip_end = start - 1;
513 		skip = skip_end - skip_start + 1;
514 	} else {
515 		dev_dbg(dev, "mode not set\n");
516 		rc = -EINVAL;
517 		goto out;
518 	}
519 
520 	if (size > avail) {
521 		dev_dbg(dev, "%pa exceeds available %s capacity: %pa\n", &size,
522 			cxled->mode == CXL_DECODER_RAM ? "ram" : "pmem",
523 			&avail);
524 		rc = -ENOSPC;
525 		goto out;
526 	}
527 
528 	rc = __cxl_dpa_reserve(cxled, start, size, skip);
529 out:
530 	up_write(&cxl_dpa_rwsem);
531 
532 	if (rc)
533 		return rc;
534 
535 	return devm_add_action_or_reset(&port->dev, cxl_dpa_release, cxled);
536 }
537 
538 static void cxld_set_interleave(struct cxl_decoder *cxld, u32 *ctrl)
539 {
540 	u16 eig;
541 	u8 eiw;
542 
543 	/*
544 	 * Input validation ensures these warns never fire, but otherwise
545 	 * suppress unititalized variable usage warnings.
546 	 */
547 	if (WARN_ONCE(ways_to_eiw(cxld->interleave_ways, &eiw),
548 		      "invalid interleave_ways: %d\n", cxld->interleave_ways))
549 		return;
550 	if (WARN_ONCE(granularity_to_eig(cxld->interleave_granularity, &eig),
551 		      "invalid interleave_granularity: %d\n",
552 		      cxld->interleave_granularity))
553 		return;
554 
555 	u32p_replace_bits(ctrl, eig, CXL_HDM_DECODER0_CTRL_IG_MASK);
556 	u32p_replace_bits(ctrl, eiw, CXL_HDM_DECODER0_CTRL_IW_MASK);
557 	*ctrl |= CXL_HDM_DECODER0_CTRL_COMMIT;
558 }
559 
560 static void cxld_set_type(struct cxl_decoder *cxld, u32 *ctrl)
561 {
562 	u32p_replace_bits(ctrl,
563 			  !!(cxld->target_type == CXL_DECODER_HOSTONLYMEM),
564 			  CXL_HDM_DECODER0_CTRL_HOSTONLY);
565 }
566 
567 static void cxlsd_set_targets(struct cxl_switch_decoder *cxlsd, u64 *tgt)
568 {
569 	struct cxl_dport **t = &cxlsd->target[0];
570 	int ways = cxlsd->cxld.interleave_ways;
571 
572 	*tgt = FIELD_PREP(GENMASK(7, 0), t[0]->port_id);
573 	if (ways > 1)
574 		*tgt |= FIELD_PREP(GENMASK(15, 8), t[1]->port_id);
575 	if (ways > 2)
576 		*tgt |= FIELD_PREP(GENMASK(23, 16), t[2]->port_id);
577 	if (ways > 3)
578 		*tgt |= FIELD_PREP(GENMASK(31, 24), t[3]->port_id);
579 	if (ways > 4)
580 		*tgt |= FIELD_PREP(GENMASK_ULL(39, 32), t[4]->port_id);
581 	if (ways > 5)
582 		*tgt |= FIELD_PREP(GENMASK_ULL(47, 40), t[5]->port_id);
583 	if (ways > 6)
584 		*tgt |= FIELD_PREP(GENMASK_ULL(55, 48), t[6]->port_id);
585 	if (ways > 7)
586 		*tgt |= FIELD_PREP(GENMASK_ULL(63, 56), t[7]->port_id);
587 }
588 
589 /*
590  * Per CXL 2.0 8.2.5.12.20 Committing Decoder Programming, hardware must set
591  * committed or error within 10ms, but just be generous with 20ms to account for
592  * clock skew and other marginal behavior
593  */
594 #define COMMIT_TIMEOUT_MS 20
595 static int cxld_await_commit(void __iomem *hdm, int id)
596 {
597 	u32 ctrl;
598 	int i;
599 
600 	for (i = 0; i < COMMIT_TIMEOUT_MS; i++) {
601 		ctrl = readl(hdm + CXL_HDM_DECODER0_CTRL_OFFSET(id));
602 		if (FIELD_GET(CXL_HDM_DECODER0_CTRL_COMMIT_ERROR, ctrl)) {
603 			ctrl &= ~CXL_HDM_DECODER0_CTRL_COMMIT;
604 			writel(ctrl, hdm + CXL_HDM_DECODER0_CTRL_OFFSET(id));
605 			return -EIO;
606 		}
607 		if (FIELD_GET(CXL_HDM_DECODER0_CTRL_COMMITTED, ctrl))
608 			return 0;
609 		fsleep(1000);
610 	}
611 
612 	return -ETIMEDOUT;
613 }
614 
615 static int cxl_decoder_commit(struct cxl_decoder *cxld)
616 {
617 	struct cxl_port *port = to_cxl_port(cxld->dev.parent);
618 	struct cxl_hdm *cxlhdm = dev_get_drvdata(&port->dev);
619 	void __iomem *hdm = cxlhdm->regs.hdm_decoder;
620 	int id = cxld->id, rc;
621 	u64 base, size;
622 	u32 ctrl;
623 
624 	if (cxld->flags & CXL_DECODER_F_ENABLE)
625 		return 0;
626 
627 	if (cxl_num_decoders_committed(port) != id) {
628 		dev_dbg(&port->dev,
629 			"%s: out of order commit, expected decoder%d.%d\n",
630 			dev_name(&cxld->dev), port->id,
631 			cxl_num_decoders_committed(port));
632 		return -EBUSY;
633 	}
634 
635 	/*
636 	 * For endpoint decoders hosted on CXL memory devices that
637 	 * support the sanitize operation, make sure sanitize is not in-flight.
638 	 */
639 	if (is_endpoint_decoder(&cxld->dev)) {
640 		struct cxl_endpoint_decoder *cxled =
641 			to_cxl_endpoint_decoder(&cxld->dev);
642 		struct cxl_memdev *cxlmd = cxled_to_memdev(cxled);
643 		struct cxl_memdev_state *mds =
644 			to_cxl_memdev_state(cxlmd->cxlds);
645 
646 		if (mds && mds->security.sanitize_active) {
647 			dev_dbg(&cxlmd->dev,
648 				"attempted to commit %s during sanitize\n",
649 				dev_name(&cxld->dev));
650 			return -EBUSY;
651 		}
652 	}
653 
654 	down_read(&cxl_dpa_rwsem);
655 	/* common decoder settings */
656 	ctrl = readl(hdm + CXL_HDM_DECODER0_CTRL_OFFSET(cxld->id));
657 	cxld_set_interleave(cxld, &ctrl);
658 	cxld_set_type(cxld, &ctrl);
659 	base = cxld->hpa_range.start;
660 	size = range_len(&cxld->hpa_range);
661 
662 	writel(upper_32_bits(base), hdm + CXL_HDM_DECODER0_BASE_HIGH_OFFSET(id));
663 	writel(lower_32_bits(base), hdm + CXL_HDM_DECODER0_BASE_LOW_OFFSET(id));
664 	writel(upper_32_bits(size), hdm + CXL_HDM_DECODER0_SIZE_HIGH_OFFSET(id));
665 	writel(lower_32_bits(size), hdm + CXL_HDM_DECODER0_SIZE_LOW_OFFSET(id));
666 
667 	if (is_switch_decoder(&cxld->dev)) {
668 		struct cxl_switch_decoder *cxlsd =
669 			to_cxl_switch_decoder(&cxld->dev);
670 		void __iomem *tl_hi = hdm + CXL_HDM_DECODER0_TL_HIGH(id);
671 		void __iomem *tl_lo = hdm + CXL_HDM_DECODER0_TL_LOW(id);
672 		u64 targets;
673 
674 		cxlsd_set_targets(cxlsd, &targets);
675 		writel(upper_32_bits(targets), tl_hi);
676 		writel(lower_32_bits(targets), tl_lo);
677 	} else {
678 		struct cxl_endpoint_decoder *cxled =
679 			to_cxl_endpoint_decoder(&cxld->dev);
680 		void __iomem *sk_hi = hdm + CXL_HDM_DECODER0_SKIP_HIGH(id);
681 		void __iomem *sk_lo = hdm + CXL_HDM_DECODER0_SKIP_LOW(id);
682 
683 		writel(upper_32_bits(cxled->skip), sk_hi);
684 		writel(lower_32_bits(cxled->skip), sk_lo);
685 	}
686 
687 	writel(ctrl, hdm + CXL_HDM_DECODER0_CTRL_OFFSET(id));
688 	up_read(&cxl_dpa_rwsem);
689 
690 	port->commit_end++;
691 	rc = cxld_await_commit(hdm, cxld->id);
692 	if (rc) {
693 		dev_dbg(&port->dev, "%s: error %d committing decoder\n",
694 			dev_name(&cxld->dev), rc);
695 		cxld->reset(cxld);
696 		return rc;
697 	}
698 	cxld->flags |= CXL_DECODER_F_ENABLE;
699 
700 	return 0;
701 }
702 
703 static int cxl_decoder_reset(struct cxl_decoder *cxld)
704 {
705 	struct cxl_port *port = to_cxl_port(cxld->dev.parent);
706 	struct cxl_hdm *cxlhdm = dev_get_drvdata(&port->dev);
707 	void __iomem *hdm = cxlhdm->regs.hdm_decoder;
708 	int id = cxld->id;
709 	u32 ctrl;
710 
711 	if ((cxld->flags & CXL_DECODER_F_ENABLE) == 0)
712 		return 0;
713 
714 	if (port->commit_end != id) {
715 		dev_dbg(&port->dev,
716 			"%s: out of order reset, expected decoder%d.%d\n",
717 			dev_name(&cxld->dev), port->id, port->commit_end);
718 		return -EBUSY;
719 	}
720 
721 	down_read(&cxl_dpa_rwsem);
722 	ctrl = readl(hdm + CXL_HDM_DECODER0_CTRL_OFFSET(id));
723 	ctrl &= ~CXL_HDM_DECODER0_CTRL_COMMIT;
724 	writel(ctrl, hdm + CXL_HDM_DECODER0_CTRL_OFFSET(id));
725 
726 	writel(0, hdm + CXL_HDM_DECODER0_SIZE_HIGH_OFFSET(id));
727 	writel(0, hdm + CXL_HDM_DECODER0_SIZE_LOW_OFFSET(id));
728 	writel(0, hdm + CXL_HDM_DECODER0_BASE_HIGH_OFFSET(id));
729 	writel(0, hdm + CXL_HDM_DECODER0_BASE_LOW_OFFSET(id));
730 	up_read(&cxl_dpa_rwsem);
731 
732 	port->commit_end--;
733 	cxld->flags &= ~CXL_DECODER_F_ENABLE;
734 
735 	/* Userspace is now responsible for reconfiguring this decoder */
736 	if (is_endpoint_decoder(&cxld->dev)) {
737 		struct cxl_endpoint_decoder *cxled;
738 
739 		cxled = to_cxl_endpoint_decoder(&cxld->dev);
740 		cxled->state = CXL_DECODER_STATE_MANUAL;
741 	}
742 
743 	return 0;
744 }
745 
746 static int cxl_setup_hdm_decoder_from_dvsec(
747 	struct cxl_port *port, struct cxl_decoder *cxld, u64 *dpa_base,
748 	int which, struct cxl_endpoint_dvsec_info *info)
749 {
750 	struct cxl_endpoint_decoder *cxled;
751 	u64 len;
752 	int rc;
753 
754 	if (!is_cxl_endpoint(port))
755 		return -EOPNOTSUPP;
756 
757 	cxled = to_cxl_endpoint_decoder(&cxld->dev);
758 	len = range_len(&info->dvsec_range[which]);
759 	if (!len)
760 		return -ENOENT;
761 
762 	cxld->target_type = CXL_DECODER_HOSTONLYMEM;
763 	cxld->commit = NULL;
764 	cxld->reset = NULL;
765 	cxld->hpa_range = info->dvsec_range[which];
766 
767 	/*
768 	 * Set the emulated decoder as locked pending additional support to
769 	 * change the range registers at run time.
770 	 */
771 	cxld->flags |= CXL_DECODER_F_ENABLE | CXL_DECODER_F_LOCK;
772 	port->commit_end = cxld->id;
773 
774 	rc = devm_cxl_dpa_reserve(cxled, *dpa_base, len, 0);
775 	if (rc) {
776 		dev_err(&port->dev,
777 			"decoder%d.%d: Failed to reserve DPA range %#llx - %#llx\n (%d)",
778 			port->id, cxld->id, *dpa_base, *dpa_base + len - 1, rc);
779 		return rc;
780 	}
781 	*dpa_base += len;
782 	cxled->state = CXL_DECODER_STATE_AUTO;
783 
784 	return 0;
785 }
786 
787 static int init_hdm_decoder(struct cxl_port *port, struct cxl_decoder *cxld,
788 			    int *target_map, void __iomem *hdm, int which,
789 			    u64 *dpa_base, struct cxl_endpoint_dvsec_info *info)
790 {
791 	struct cxl_endpoint_decoder *cxled = NULL;
792 	u64 size, base, skip, dpa_size, lo, hi;
793 	bool committed;
794 	u32 remainder;
795 	int i, rc;
796 	u32 ctrl;
797 	union {
798 		u64 value;
799 		unsigned char target_id[8];
800 	} target_list;
801 
802 	if (should_emulate_decoders(info))
803 		return cxl_setup_hdm_decoder_from_dvsec(port, cxld, dpa_base,
804 							which, info);
805 
806 	ctrl = readl(hdm + CXL_HDM_DECODER0_CTRL_OFFSET(which));
807 	lo = readl(hdm + CXL_HDM_DECODER0_BASE_LOW_OFFSET(which));
808 	hi = readl(hdm + CXL_HDM_DECODER0_BASE_HIGH_OFFSET(which));
809 	base = (hi << 32) + lo;
810 	lo = readl(hdm + CXL_HDM_DECODER0_SIZE_LOW_OFFSET(which));
811 	hi = readl(hdm + CXL_HDM_DECODER0_SIZE_HIGH_OFFSET(which));
812 	size = (hi << 32) + lo;
813 	committed = !!(ctrl & CXL_HDM_DECODER0_CTRL_COMMITTED);
814 	cxld->commit = cxl_decoder_commit;
815 	cxld->reset = cxl_decoder_reset;
816 
817 	if (!committed)
818 		size = 0;
819 	if (base == U64_MAX || size == U64_MAX) {
820 		dev_warn(&port->dev, "decoder%d.%d: Invalid resource range\n",
821 			 port->id, cxld->id);
822 		return -ENXIO;
823 	}
824 
825 	if (info)
826 		cxled = to_cxl_endpoint_decoder(&cxld->dev);
827 	cxld->hpa_range = (struct range) {
828 		.start = base,
829 		.end = base + size - 1,
830 	};
831 
832 	/* decoders are enabled if committed */
833 	if (committed) {
834 		cxld->flags |= CXL_DECODER_F_ENABLE;
835 		if (ctrl & CXL_HDM_DECODER0_CTRL_LOCK)
836 			cxld->flags |= CXL_DECODER_F_LOCK;
837 		if (FIELD_GET(CXL_HDM_DECODER0_CTRL_HOSTONLY, ctrl))
838 			cxld->target_type = CXL_DECODER_HOSTONLYMEM;
839 		else
840 			cxld->target_type = CXL_DECODER_DEVMEM;
841 
842 		guard(rwsem_write)(&cxl_region_rwsem);
843 		if (cxld->id != cxl_num_decoders_committed(port)) {
844 			dev_warn(&port->dev,
845 				 "decoder%d.%d: Committed out of order\n",
846 				 port->id, cxld->id);
847 			return -ENXIO;
848 		}
849 
850 		if (size == 0) {
851 			dev_warn(&port->dev,
852 				 "decoder%d.%d: Committed with zero size\n",
853 				 port->id, cxld->id);
854 			return -ENXIO;
855 		}
856 		port->commit_end = cxld->id;
857 	} else {
858 		if (cxled) {
859 			struct cxl_memdev *cxlmd = cxled_to_memdev(cxled);
860 			struct cxl_dev_state *cxlds = cxlmd->cxlds;
861 
862 			/*
863 			 * Default by devtype until a device arrives that needs
864 			 * more precision.
865 			 */
866 			if (cxlds->type == CXL_DEVTYPE_CLASSMEM)
867 				cxld->target_type = CXL_DECODER_HOSTONLYMEM;
868 			else
869 				cxld->target_type = CXL_DECODER_DEVMEM;
870 		} else {
871 			/* To be overridden by region type at commit time */
872 			cxld->target_type = CXL_DECODER_HOSTONLYMEM;
873 		}
874 
875 		if (!FIELD_GET(CXL_HDM_DECODER0_CTRL_HOSTONLY, ctrl) &&
876 		    cxld->target_type == CXL_DECODER_HOSTONLYMEM) {
877 			ctrl |= CXL_HDM_DECODER0_CTRL_HOSTONLY;
878 			writel(ctrl, hdm + CXL_HDM_DECODER0_CTRL_OFFSET(which));
879 		}
880 	}
881 	rc = eiw_to_ways(FIELD_GET(CXL_HDM_DECODER0_CTRL_IW_MASK, ctrl),
882 			  &cxld->interleave_ways);
883 	if (rc) {
884 		dev_warn(&port->dev,
885 			 "decoder%d.%d: Invalid interleave ways (ctrl: %#x)\n",
886 			 port->id, cxld->id, ctrl);
887 		return rc;
888 	}
889 	rc = eig_to_granularity(FIELD_GET(CXL_HDM_DECODER0_CTRL_IG_MASK, ctrl),
890 				 &cxld->interleave_granularity);
891 	if (rc)
892 		return rc;
893 
894 	dev_dbg(&port->dev, "decoder%d.%d: range: %#llx-%#llx iw: %d ig: %d\n",
895 		port->id, cxld->id, cxld->hpa_range.start, cxld->hpa_range.end,
896 		cxld->interleave_ways, cxld->interleave_granularity);
897 
898 	if (!cxled) {
899 		lo = readl(hdm + CXL_HDM_DECODER0_TL_LOW(which));
900 		hi = readl(hdm + CXL_HDM_DECODER0_TL_HIGH(which));
901 		target_list.value = (hi << 32) + lo;
902 		for (i = 0; i < cxld->interleave_ways; i++)
903 			target_map[i] = target_list.target_id[i];
904 
905 		return 0;
906 	}
907 
908 	if (!committed)
909 		return 0;
910 
911 	dpa_size = div_u64_rem(size, cxld->interleave_ways, &remainder);
912 	if (remainder) {
913 		dev_err(&port->dev,
914 			"decoder%d.%d: invalid committed configuration size: %#llx ways: %d\n",
915 			port->id, cxld->id, size, cxld->interleave_ways);
916 		return -ENXIO;
917 	}
918 	lo = readl(hdm + CXL_HDM_DECODER0_SKIP_LOW(which));
919 	hi = readl(hdm + CXL_HDM_DECODER0_SKIP_HIGH(which));
920 	skip = (hi << 32) + lo;
921 	rc = devm_cxl_dpa_reserve(cxled, *dpa_base + skip, dpa_size, skip);
922 	if (rc) {
923 		dev_err(&port->dev,
924 			"decoder%d.%d: Failed to reserve DPA range %#llx - %#llx\n (%d)",
925 			port->id, cxld->id, *dpa_base,
926 			*dpa_base + dpa_size + skip - 1, rc);
927 		return rc;
928 	}
929 	*dpa_base += dpa_size + skip;
930 
931 	cxled->state = CXL_DECODER_STATE_AUTO;
932 
933 	return 0;
934 }
935 
936 static void cxl_settle_decoders(struct cxl_hdm *cxlhdm)
937 {
938 	void __iomem *hdm = cxlhdm->regs.hdm_decoder;
939 	int committed, i;
940 	u32 ctrl;
941 
942 	if (!hdm)
943 		return;
944 
945 	/*
946 	 * Since the register resource was recently claimed via request_region()
947 	 * be careful about trusting the "not-committed" status until the commit
948 	 * timeout has elapsed.  The commit timeout is 10ms (CXL 2.0
949 	 * 8.2.5.12.20), but double it to be tolerant of any clock skew between
950 	 * host and target.
951 	 */
952 	for (i = 0, committed = 0; i < cxlhdm->decoder_count; i++) {
953 		ctrl = readl(hdm + CXL_HDM_DECODER0_CTRL_OFFSET(i));
954 		if (ctrl & CXL_HDM_DECODER0_CTRL_COMMITTED)
955 			committed++;
956 	}
957 
958 	/* ensure that future checks of committed can be trusted */
959 	if (committed != cxlhdm->decoder_count)
960 		msleep(20);
961 }
962 
963 /**
964  * devm_cxl_enumerate_decoders - add decoder objects per HDM register set
965  * @cxlhdm: Structure to populate with HDM capabilities
966  * @info: cached DVSEC range register info
967  */
968 int devm_cxl_enumerate_decoders(struct cxl_hdm *cxlhdm,
969 				struct cxl_endpoint_dvsec_info *info)
970 {
971 	void __iomem *hdm = cxlhdm->regs.hdm_decoder;
972 	struct cxl_port *port = cxlhdm->port;
973 	int i;
974 	u64 dpa_base = 0;
975 
976 	cxl_settle_decoders(cxlhdm);
977 
978 	for (i = 0; i < cxlhdm->decoder_count; i++) {
979 		int target_map[CXL_DECODER_MAX_INTERLEAVE] = { 0 };
980 		int rc, target_count = cxlhdm->target_count;
981 		struct cxl_decoder *cxld;
982 
983 		if (is_cxl_endpoint(port)) {
984 			struct cxl_endpoint_decoder *cxled;
985 
986 			cxled = cxl_endpoint_decoder_alloc(port);
987 			if (IS_ERR(cxled)) {
988 				dev_warn(&port->dev,
989 					 "Failed to allocate decoder%d.%d\n",
990 					 port->id, i);
991 				return PTR_ERR(cxled);
992 			}
993 			cxld = &cxled->cxld;
994 		} else {
995 			struct cxl_switch_decoder *cxlsd;
996 
997 			cxlsd = cxl_switch_decoder_alloc(port, target_count);
998 			if (IS_ERR(cxlsd)) {
999 				dev_warn(&port->dev,
1000 					 "Failed to allocate decoder%d.%d\n",
1001 					 port->id, i);
1002 				return PTR_ERR(cxlsd);
1003 			}
1004 			cxld = &cxlsd->cxld;
1005 		}
1006 
1007 		rc = init_hdm_decoder(port, cxld, target_map, hdm, i,
1008 				      &dpa_base, info);
1009 		if (rc) {
1010 			dev_warn(&port->dev,
1011 				 "Failed to initialize decoder%d.%d\n",
1012 				 port->id, i);
1013 			put_device(&cxld->dev);
1014 			return rc;
1015 		}
1016 		rc = add_hdm_decoder(port, cxld, target_map);
1017 		if (rc) {
1018 			dev_warn(&port->dev,
1019 				 "Failed to add decoder%d.%d\n", port->id, i);
1020 			return rc;
1021 		}
1022 	}
1023 
1024 	return 0;
1025 }
1026 EXPORT_SYMBOL_NS_GPL(devm_cxl_enumerate_decoders, CXL);
1027