xref: /openbmc/linux/drivers/cxl/core/hdm.c (revision 98a52692)
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 int map_hdm_decoder_regs(struct cxl_port *port, void __iomem *crb,
85 				struct cxl_component_regs *regs)
86 {
87 	struct cxl_register_map map = {
88 		.host = &port->dev,
89 		.resource = port->component_reg_phys,
90 		.base = crb,
91 		.max_size = CXL_COMPONENT_REG_BLOCK_SIZE,
92 	};
93 
94 	cxl_probe_component_regs(&port->dev, crb, &map.component_map);
95 	if (!map.component_map.hdm_decoder.valid) {
96 		dev_dbg(&port->dev, "HDM decoder registers not implemented\n");
97 		/* unique error code to indicate no HDM decoder capability */
98 		return -ENODEV;
99 	}
100 
101 	return cxl_map_component_regs(&map, regs, BIT(CXL_CM_CAP_CAP_ID_HDM));
102 }
103 
104 static bool should_emulate_decoders(struct cxl_endpoint_dvsec_info *info)
105 {
106 	struct cxl_hdm *cxlhdm;
107 	void __iomem *hdm;
108 	u32 ctrl;
109 	int i;
110 
111 	if (!info)
112 		return false;
113 
114 	cxlhdm = dev_get_drvdata(&info->port->dev);
115 	hdm = cxlhdm->regs.hdm_decoder;
116 
117 	if (!hdm)
118 		return true;
119 
120 	/*
121 	 * If HDM decoders are present and the driver is in control of
122 	 * Mem_Enable skip DVSEC based emulation
123 	 */
124 	if (!info->mem_enabled)
125 		return false;
126 
127 	/*
128 	 * If any decoders are committed already, there should not be any
129 	 * emulated DVSEC decoders.
130 	 */
131 	for (i = 0; i < cxlhdm->decoder_count; i++) {
132 		ctrl = readl(hdm + CXL_HDM_DECODER0_CTRL_OFFSET(i));
133 		dev_dbg(&info->port->dev,
134 			"decoder%d.%d: committed: %ld base: %#x_%.8x size: %#x_%.8x\n",
135 			info->port->id, i,
136 			FIELD_GET(CXL_HDM_DECODER0_CTRL_COMMITTED, ctrl),
137 			readl(hdm + CXL_HDM_DECODER0_BASE_HIGH_OFFSET(i)),
138 			readl(hdm + CXL_HDM_DECODER0_BASE_LOW_OFFSET(i)),
139 			readl(hdm + CXL_HDM_DECODER0_SIZE_HIGH_OFFSET(i)),
140 			readl(hdm + CXL_HDM_DECODER0_SIZE_LOW_OFFSET(i)));
141 		if (FIELD_GET(CXL_HDM_DECODER0_CTRL_COMMITTED, ctrl))
142 			return false;
143 	}
144 
145 	return true;
146 }
147 
148 /**
149  * devm_cxl_setup_hdm - map HDM decoder component registers
150  * @port: cxl_port to map
151  * @info: cached DVSEC range register info
152  */
153 struct cxl_hdm *devm_cxl_setup_hdm(struct cxl_port *port,
154 				   struct cxl_endpoint_dvsec_info *info)
155 {
156 	struct device *dev = &port->dev;
157 	struct cxl_hdm *cxlhdm;
158 	void __iomem *crb;
159 	int rc;
160 
161 	cxlhdm = devm_kzalloc(dev, sizeof(*cxlhdm), GFP_KERNEL);
162 	if (!cxlhdm)
163 		return ERR_PTR(-ENOMEM);
164 	cxlhdm->port = port;
165 	dev_set_drvdata(dev, cxlhdm);
166 
167 	crb = ioremap(port->component_reg_phys, CXL_COMPONENT_REG_BLOCK_SIZE);
168 	if (!crb && info && info->mem_enabled) {
169 		cxlhdm->decoder_count = info->ranges;
170 		return cxlhdm;
171 	} else if (!crb) {
172 		dev_err(dev, "No component registers mapped\n");
173 		return ERR_PTR(-ENXIO);
174 	}
175 
176 	rc = map_hdm_decoder_regs(port, crb, &cxlhdm->regs);
177 	iounmap(crb);
178 	if (rc)
179 		return ERR_PTR(rc);
180 
181 	parse_hdm_decoder_caps(cxlhdm);
182 	if (cxlhdm->decoder_count == 0) {
183 		dev_err(dev, "Spec violation. Caps invalid\n");
184 		return ERR_PTR(-ENXIO);
185 	}
186 
187 	/*
188 	 * Now that the hdm capability is parsed, decide if range
189 	 * register emulation is needed and fixup cxlhdm accordingly.
190 	 */
191 	if (should_emulate_decoders(info)) {
192 		dev_dbg(dev, "Fallback map %d range register%s\n", info->ranges,
193 			info->ranges > 1 ? "s" : "");
194 		cxlhdm->decoder_count = info->ranges;
195 	}
196 
197 	return cxlhdm;
198 }
199 EXPORT_SYMBOL_NS_GPL(devm_cxl_setup_hdm, CXL);
200 
201 static void __cxl_dpa_debug(struct seq_file *file, struct resource *r, int depth)
202 {
203 	unsigned long long start = r->start, end = r->end;
204 
205 	seq_printf(file, "%*s%08llx-%08llx : %s\n", depth * 2, "", start, end,
206 		   r->name);
207 }
208 
209 void cxl_dpa_debug(struct seq_file *file, struct cxl_dev_state *cxlds)
210 {
211 	struct resource *p1, *p2;
212 
213 	down_read(&cxl_dpa_rwsem);
214 	for (p1 = cxlds->dpa_res.child; p1; p1 = p1->sibling) {
215 		__cxl_dpa_debug(file, p1, 0);
216 		for (p2 = p1->child; p2; p2 = p2->sibling)
217 			__cxl_dpa_debug(file, p2, 1);
218 	}
219 	up_read(&cxl_dpa_rwsem);
220 }
221 EXPORT_SYMBOL_NS_GPL(cxl_dpa_debug, CXL);
222 
223 /*
224  * Must be called in a context that synchronizes against this decoder's
225  * port ->remove() callback (like an endpoint decoder sysfs attribute)
226  */
227 static void __cxl_dpa_release(struct cxl_endpoint_decoder *cxled)
228 {
229 	struct cxl_memdev *cxlmd = cxled_to_memdev(cxled);
230 	struct cxl_port *port = cxled_to_port(cxled);
231 	struct cxl_dev_state *cxlds = cxlmd->cxlds;
232 	struct resource *res = cxled->dpa_res;
233 	resource_size_t skip_start;
234 
235 	lockdep_assert_held_write(&cxl_dpa_rwsem);
236 
237 	/* save @skip_start, before @res is released */
238 	skip_start = res->start - cxled->skip;
239 	__release_region(&cxlds->dpa_res, res->start, resource_size(res));
240 	if (cxled->skip)
241 		__release_region(&cxlds->dpa_res, skip_start, cxled->skip);
242 	cxled->skip = 0;
243 	cxled->dpa_res = NULL;
244 	put_device(&cxled->cxld.dev);
245 	port->hdm_end--;
246 }
247 
248 static void cxl_dpa_release(void *cxled)
249 {
250 	down_write(&cxl_dpa_rwsem);
251 	__cxl_dpa_release(cxled);
252 	up_write(&cxl_dpa_rwsem);
253 }
254 
255 /*
256  * Must be called from context that will not race port device
257  * unregistration, like decoder sysfs attribute methods
258  */
259 static void devm_cxl_dpa_release(struct cxl_endpoint_decoder *cxled)
260 {
261 	struct cxl_port *port = cxled_to_port(cxled);
262 
263 	lockdep_assert_held_write(&cxl_dpa_rwsem);
264 	devm_remove_action(&port->dev, cxl_dpa_release, cxled);
265 	__cxl_dpa_release(cxled);
266 }
267 
268 static int __cxl_dpa_reserve(struct cxl_endpoint_decoder *cxled,
269 			     resource_size_t base, resource_size_t len,
270 			     resource_size_t skipped)
271 {
272 	struct cxl_memdev *cxlmd = cxled_to_memdev(cxled);
273 	struct cxl_port *port = cxled_to_port(cxled);
274 	struct cxl_dev_state *cxlds = cxlmd->cxlds;
275 	struct device *dev = &port->dev;
276 	struct resource *res;
277 
278 	lockdep_assert_held_write(&cxl_dpa_rwsem);
279 
280 	if (!len) {
281 		dev_warn(dev, "decoder%d.%d: empty reservation attempted\n",
282 			 port->id, cxled->cxld.id);
283 		return -EINVAL;
284 	}
285 
286 	if (cxled->dpa_res) {
287 		dev_dbg(dev, "decoder%d.%d: existing allocation %pr assigned\n",
288 			port->id, cxled->cxld.id, cxled->dpa_res);
289 		return -EBUSY;
290 	}
291 
292 	if (port->hdm_end + 1 != cxled->cxld.id) {
293 		/*
294 		 * Assumes alloc and commit order is always in hardware instance
295 		 * order per expectations from 8.2.5.12.20 Committing Decoder
296 		 * Programming that enforce decoder[m] committed before
297 		 * decoder[m+1] commit start.
298 		 */
299 		dev_dbg(dev, "decoder%d.%d: expected decoder%d.%d\n", port->id,
300 			cxled->cxld.id, port->id, port->hdm_end + 1);
301 		return -EBUSY;
302 	}
303 
304 	if (skipped) {
305 		res = __request_region(&cxlds->dpa_res, base - skipped, skipped,
306 				       dev_name(&cxled->cxld.dev), 0);
307 		if (!res) {
308 			dev_dbg(dev,
309 				"decoder%d.%d: failed to reserve skipped space\n",
310 				port->id, cxled->cxld.id);
311 			return -EBUSY;
312 		}
313 	}
314 	res = __request_region(&cxlds->dpa_res, base, len,
315 			       dev_name(&cxled->cxld.dev), 0);
316 	if (!res) {
317 		dev_dbg(dev, "decoder%d.%d: failed to reserve allocation\n",
318 			port->id, cxled->cxld.id);
319 		if (skipped)
320 			__release_region(&cxlds->dpa_res, base - skipped,
321 					 skipped);
322 		return -EBUSY;
323 	}
324 	cxled->dpa_res = res;
325 	cxled->skip = skipped;
326 
327 	if (resource_contains(&cxlds->pmem_res, res))
328 		cxled->mode = CXL_DECODER_PMEM;
329 	else if (resource_contains(&cxlds->ram_res, res))
330 		cxled->mode = CXL_DECODER_RAM;
331 	else {
332 		dev_dbg(dev, "decoder%d.%d: %pr mixed\n", port->id,
333 			cxled->cxld.id, cxled->dpa_res);
334 		cxled->mode = CXL_DECODER_MIXED;
335 	}
336 
337 	port->hdm_end++;
338 	get_device(&cxled->cxld.dev);
339 	return 0;
340 }
341 
342 int devm_cxl_dpa_reserve(struct cxl_endpoint_decoder *cxled,
343 				resource_size_t base, resource_size_t len,
344 				resource_size_t skipped)
345 {
346 	struct cxl_port *port = cxled_to_port(cxled);
347 	int rc;
348 
349 	down_write(&cxl_dpa_rwsem);
350 	rc = __cxl_dpa_reserve(cxled, base, len, skipped);
351 	up_write(&cxl_dpa_rwsem);
352 
353 	if (rc)
354 		return rc;
355 
356 	return devm_add_action_or_reset(&port->dev, cxl_dpa_release, cxled);
357 }
358 EXPORT_SYMBOL_NS_GPL(devm_cxl_dpa_reserve, CXL);
359 
360 resource_size_t cxl_dpa_size(struct cxl_endpoint_decoder *cxled)
361 {
362 	resource_size_t size = 0;
363 
364 	down_read(&cxl_dpa_rwsem);
365 	if (cxled->dpa_res)
366 		size = resource_size(cxled->dpa_res);
367 	up_read(&cxl_dpa_rwsem);
368 
369 	return size;
370 }
371 
372 resource_size_t cxl_dpa_resource_start(struct cxl_endpoint_decoder *cxled)
373 {
374 	resource_size_t base = -1;
375 
376 	down_read(&cxl_dpa_rwsem);
377 	if (cxled->dpa_res)
378 		base = cxled->dpa_res->start;
379 	up_read(&cxl_dpa_rwsem);
380 
381 	return base;
382 }
383 
384 int cxl_dpa_free(struct cxl_endpoint_decoder *cxled)
385 {
386 	struct cxl_port *port = cxled_to_port(cxled);
387 	struct device *dev = &cxled->cxld.dev;
388 	int rc;
389 
390 	down_write(&cxl_dpa_rwsem);
391 	if (!cxled->dpa_res) {
392 		rc = 0;
393 		goto out;
394 	}
395 	if (cxled->cxld.region) {
396 		dev_dbg(dev, "decoder assigned to: %s\n",
397 			dev_name(&cxled->cxld.region->dev));
398 		rc = -EBUSY;
399 		goto out;
400 	}
401 	if (cxled->cxld.flags & CXL_DECODER_F_ENABLE) {
402 		dev_dbg(dev, "decoder enabled\n");
403 		rc = -EBUSY;
404 		goto out;
405 	}
406 	if (cxled->cxld.id != port->hdm_end) {
407 		dev_dbg(dev, "expected decoder%d.%d\n", port->id,
408 			port->hdm_end);
409 		rc = -EBUSY;
410 		goto out;
411 	}
412 	devm_cxl_dpa_release(cxled);
413 	rc = 0;
414 out:
415 	up_write(&cxl_dpa_rwsem);
416 	return rc;
417 }
418 
419 int cxl_dpa_set_mode(struct cxl_endpoint_decoder *cxled,
420 		     enum cxl_decoder_mode mode)
421 {
422 	struct cxl_memdev *cxlmd = cxled_to_memdev(cxled);
423 	struct cxl_dev_state *cxlds = cxlmd->cxlds;
424 	struct device *dev = &cxled->cxld.dev;
425 	int rc;
426 
427 	switch (mode) {
428 	case CXL_DECODER_RAM:
429 	case CXL_DECODER_PMEM:
430 		break;
431 	default:
432 		dev_dbg(dev, "unsupported mode: %d\n", mode);
433 		return -EINVAL;
434 	}
435 
436 	down_write(&cxl_dpa_rwsem);
437 	if (cxled->cxld.flags & CXL_DECODER_F_ENABLE) {
438 		rc = -EBUSY;
439 		goto out;
440 	}
441 
442 	/*
443 	 * Only allow modes that are supported by the current partition
444 	 * configuration
445 	 */
446 	if (mode == CXL_DECODER_PMEM && !resource_size(&cxlds->pmem_res)) {
447 		dev_dbg(dev, "no available pmem capacity\n");
448 		rc = -ENXIO;
449 		goto out;
450 	}
451 	if (mode == CXL_DECODER_RAM && !resource_size(&cxlds->ram_res)) {
452 		dev_dbg(dev, "no available ram capacity\n");
453 		rc = -ENXIO;
454 		goto out;
455 	}
456 
457 	cxled->mode = mode;
458 	rc = 0;
459 out:
460 	up_write(&cxl_dpa_rwsem);
461 
462 	return rc;
463 }
464 
465 int cxl_dpa_alloc(struct cxl_endpoint_decoder *cxled, unsigned long long size)
466 {
467 	struct cxl_memdev *cxlmd = cxled_to_memdev(cxled);
468 	resource_size_t free_ram_start, free_pmem_start;
469 	struct cxl_port *port = cxled_to_port(cxled);
470 	struct cxl_dev_state *cxlds = cxlmd->cxlds;
471 	struct device *dev = &cxled->cxld.dev;
472 	resource_size_t start, avail, skip;
473 	struct resource *p, *last;
474 	int rc;
475 
476 	down_write(&cxl_dpa_rwsem);
477 	if (cxled->cxld.region) {
478 		dev_dbg(dev, "decoder attached to %s\n",
479 			dev_name(&cxled->cxld.region->dev));
480 		rc = -EBUSY;
481 		goto out;
482 	}
483 
484 	if (cxled->cxld.flags & CXL_DECODER_F_ENABLE) {
485 		dev_dbg(dev, "decoder enabled\n");
486 		rc = -EBUSY;
487 		goto out;
488 	}
489 
490 	for (p = cxlds->ram_res.child, last = NULL; p; p = p->sibling)
491 		last = p;
492 	if (last)
493 		free_ram_start = last->end + 1;
494 	else
495 		free_ram_start = cxlds->ram_res.start;
496 
497 	for (p = cxlds->pmem_res.child, last = NULL; p; p = p->sibling)
498 		last = p;
499 	if (last)
500 		free_pmem_start = last->end + 1;
501 	else
502 		free_pmem_start = cxlds->pmem_res.start;
503 
504 	if (cxled->mode == CXL_DECODER_RAM) {
505 		start = free_ram_start;
506 		avail = cxlds->ram_res.end - start + 1;
507 		skip = 0;
508 	} else if (cxled->mode == CXL_DECODER_PMEM) {
509 		resource_size_t skip_start, skip_end;
510 
511 		start = free_pmem_start;
512 		avail = cxlds->pmem_res.end - start + 1;
513 		skip_start = free_ram_start;
514 
515 		/*
516 		 * If some pmem is already allocated, then that allocation
517 		 * already handled the skip.
518 		 */
519 		if (cxlds->pmem_res.child &&
520 		    skip_start == cxlds->pmem_res.child->start)
521 			skip_end = skip_start - 1;
522 		else
523 			skip_end = start - 1;
524 		skip = skip_end - skip_start + 1;
525 	} else {
526 		dev_dbg(dev, "mode not set\n");
527 		rc = -EINVAL;
528 		goto out;
529 	}
530 
531 	if (size > avail) {
532 		dev_dbg(dev, "%pa exceeds available %s capacity: %pa\n", &size,
533 			cxled->mode == CXL_DECODER_RAM ? "ram" : "pmem",
534 			&avail);
535 		rc = -ENOSPC;
536 		goto out;
537 	}
538 
539 	rc = __cxl_dpa_reserve(cxled, start, size, skip);
540 out:
541 	up_write(&cxl_dpa_rwsem);
542 
543 	if (rc)
544 		return rc;
545 
546 	return devm_add_action_or_reset(&port->dev, cxl_dpa_release, cxled);
547 }
548 
549 static void cxld_set_interleave(struct cxl_decoder *cxld, u32 *ctrl)
550 {
551 	u16 eig;
552 	u8 eiw;
553 
554 	/*
555 	 * Input validation ensures these warns never fire, but otherwise
556 	 * suppress unititalized variable usage warnings.
557 	 */
558 	if (WARN_ONCE(ways_to_eiw(cxld->interleave_ways, &eiw),
559 		      "invalid interleave_ways: %d\n", cxld->interleave_ways))
560 		return;
561 	if (WARN_ONCE(granularity_to_eig(cxld->interleave_granularity, &eig),
562 		      "invalid interleave_granularity: %d\n",
563 		      cxld->interleave_granularity))
564 		return;
565 
566 	u32p_replace_bits(ctrl, eig, CXL_HDM_DECODER0_CTRL_IG_MASK);
567 	u32p_replace_bits(ctrl, eiw, CXL_HDM_DECODER0_CTRL_IW_MASK);
568 	*ctrl |= CXL_HDM_DECODER0_CTRL_COMMIT;
569 }
570 
571 static void cxld_set_type(struct cxl_decoder *cxld, u32 *ctrl)
572 {
573 	u32p_replace_bits(ctrl,
574 			  !!(cxld->target_type == CXL_DECODER_HOSTONLYMEM),
575 			  CXL_HDM_DECODER0_CTRL_HOSTONLY);
576 }
577 
578 static void cxlsd_set_targets(struct cxl_switch_decoder *cxlsd, u64 *tgt)
579 {
580 	struct cxl_dport **t = &cxlsd->target[0];
581 	int ways = cxlsd->cxld.interleave_ways;
582 
583 	*tgt = FIELD_PREP(GENMASK(7, 0), t[0]->port_id);
584 	if (ways > 1)
585 		*tgt |= FIELD_PREP(GENMASK(15, 8), t[1]->port_id);
586 	if (ways > 2)
587 		*tgt |= FIELD_PREP(GENMASK(23, 16), t[2]->port_id);
588 	if (ways > 3)
589 		*tgt |= FIELD_PREP(GENMASK(31, 24), t[3]->port_id);
590 	if (ways > 4)
591 		*tgt |= FIELD_PREP(GENMASK_ULL(39, 32), t[4]->port_id);
592 	if (ways > 5)
593 		*tgt |= FIELD_PREP(GENMASK_ULL(47, 40), t[5]->port_id);
594 	if (ways > 6)
595 		*tgt |= FIELD_PREP(GENMASK_ULL(55, 48), t[6]->port_id);
596 	if (ways > 7)
597 		*tgt |= FIELD_PREP(GENMASK_ULL(63, 56), t[7]->port_id);
598 }
599 
600 /*
601  * Per CXL 2.0 8.2.5.12.20 Committing Decoder Programming, hardware must set
602  * committed or error within 10ms, but just be generous with 20ms to account for
603  * clock skew and other marginal behavior
604  */
605 #define COMMIT_TIMEOUT_MS 20
606 static int cxld_await_commit(void __iomem *hdm, int id)
607 {
608 	u32 ctrl;
609 	int i;
610 
611 	for (i = 0; i < COMMIT_TIMEOUT_MS; i++) {
612 		ctrl = readl(hdm + CXL_HDM_DECODER0_CTRL_OFFSET(id));
613 		if (FIELD_GET(CXL_HDM_DECODER0_CTRL_COMMIT_ERROR, ctrl)) {
614 			ctrl &= ~CXL_HDM_DECODER0_CTRL_COMMIT;
615 			writel(ctrl, hdm + CXL_HDM_DECODER0_CTRL_OFFSET(id));
616 			return -EIO;
617 		}
618 		if (FIELD_GET(CXL_HDM_DECODER0_CTRL_COMMITTED, ctrl))
619 			return 0;
620 		fsleep(1000);
621 	}
622 
623 	return -ETIMEDOUT;
624 }
625 
626 static int cxl_decoder_commit(struct cxl_decoder *cxld)
627 {
628 	struct cxl_port *port = to_cxl_port(cxld->dev.parent);
629 	struct cxl_hdm *cxlhdm = dev_get_drvdata(&port->dev);
630 	void __iomem *hdm = cxlhdm->regs.hdm_decoder;
631 	int id = cxld->id, rc;
632 	u64 base, size;
633 	u32 ctrl;
634 
635 	if (cxld->flags & CXL_DECODER_F_ENABLE)
636 		return 0;
637 
638 	if (port->commit_end + 1 != id) {
639 		dev_dbg(&port->dev,
640 			"%s: out of order commit, expected decoder%d.%d\n",
641 			dev_name(&cxld->dev), port->id, port->commit_end + 1);
642 		return -EBUSY;
643 	}
644 
645 	/*
646 	 * For endpoint decoders hosted on CXL memory devices that
647 	 * support the sanitize operation, make sure sanitize is not in-flight.
648 	 */
649 	if (is_endpoint_decoder(&cxld->dev)) {
650 		struct cxl_endpoint_decoder *cxled =
651 			to_cxl_endpoint_decoder(&cxld->dev);
652 		struct cxl_memdev *cxlmd = cxled_to_memdev(cxled);
653 		struct cxl_memdev_state *mds =
654 			to_cxl_memdev_state(cxlmd->cxlds);
655 
656 		if (mds && mds->security.sanitize_active) {
657 			dev_dbg(&cxlmd->dev,
658 				"attempted to commit %s during sanitize\n",
659 				dev_name(&cxld->dev));
660 			return -EBUSY;
661 		}
662 	}
663 
664 	down_read(&cxl_dpa_rwsem);
665 	/* common decoder settings */
666 	ctrl = readl(hdm + CXL_HDM_DECODER0_CTRL_OFFSET(cxld->id));
667 	cxld_set_interleave(cxld, &ctrl);
668 	cxld_set_type(cxld, &ctrl);
669 	base = cxld->hpa_range.start;
670 	size = range_len(&cxld->hpa_range);
671 
672 	writel(upper_32_bits(base), hdm + CXL_HDM_DECODER0_BASE_HIGH_OFFSET(id));
673 	writel(lower_32_bits(base), hdm + CXL_HDM_DECODER0_BASE_LOW_OFFSET(id));
674 	writel(upper_32_bits(size), hdm + CXL_HDM_DECODER0_SIZE_HIGH_OFFSET(id));
675 	writel(lower_32_bits(size), hdm + CXL_HDM_DECODER0_SIZE_LOW_OFFSET(id));
676 
677 	if (is_switch_decoder(&cxld->dev)) {
678 		struct cxl_switch_decoder *cxlsd =
679 			to_cxl_switch_decoder(&cxld->dev);
680 		void __iomem *tl_hi = hdm + CXL_HDM_DECODER0_TL_HIGH(id);
681 		void __iomem *tl_lo = hdm + CXL_HDM_DECODER0_TL_LOW(id);
682 		u64 targets;
683 
684 		cxlsd_set_targets(cxlsd, &targets);
685 		writel(upper_32_bits(targets), tl_hi);
686 		writel(lower_32_bits(targets), tl_lo);
687 	} else {
688 		struct cxl_endpoint_decoder *cxled =
689 			to_cxl_endpoint_decoder(&cxld->dev);
690 		void __iomem *sk_hi = hdm + CXL_HDM_DECODER0_SKIP_HIGH(id);
691 		void __iomem *sk_lo = hdm + CXL_HDM_DECODER0_SKIP_LOW(id);
692 
693 		writel(upper_32_bits(cxled->skip), sk_hi);
694 		writel(lower_32_bits(cxled->skip), sk_lo);
695 	}
696 
697 	writel(ctrl, hdm + CXL_HDM_DECODER0_CTRL_OFFSET(id));
698 	up_read(&cxl_dpa_rwsem);
699 
700 	port->commit_end++;
701 	rc = cxld_await_commit(hdm, cxld->id);
702 	if (rc) {
703 		dev_dbg(&port->dev, "%s: error %d committing decoder\n",
704 			dev_name(&cxld->dev), rc);
705 		cxld->reset(cxld);
706 		return rc;
707 	}
708 	cxld->flags |= CXL_DECODER_F_ENABLE;
709 
710 	return 0;
711 }
712 
713 static int cxl_decoder_reset(struct cxl_decoder *cxld)
714 {
715 	struct cxl_port *port = to_cxl_port(cxld->dev.parent);
716 	struct cxl_hdm *cxlhdm = dev_get_drvdata(&port->dev);
717 	void __iomem *hdm = cxlhdm->regs.hdm_decoder;
718 	int id = cxld->id;
719 	u32 ctrl;
720 
721 	if ((cxld->flags & CXL_DECODER_F_ENABLE) == 0)
722 		return 0;
723 
724 	if (port->commit_end != id) {
725 		dev_dbg(&port->dev,
726 			"%s: out of order reset, expected decoder%d.%d\n",
727 			dev_name(&cxld->dev), port->id, port->commit_end);
728 		return -EBUSY;
729 	}
730 
731 	down_read(&cxl_dpa_rwsem);
732 	ctrl = readl(hdm + CXL_HDM_DECODER0_CTRL_OFFSET(id));
733 	ctrl &= ~CXL_HDM_DECODER0_CTRL_COMMIT;
734 	writel(ctrl, hdm + CXL_HDM_DECODER0_CTRL_OFFSET(id));
735 
736 	writel(0, hdm + CXL_HDM_DECODER0_SIZE_HIGH_OFFSET(id));
737 	writel(0, hdm + CXL_HDM_DECODER0_SIZE_LOW_OFFSET(id));
738 	writel(0, hdm + CXL_HDM_DECODER0_BASE_HIGH_OFFSET(id));
739 	writel(0, hdm + CXL_HDM_DECODER0_BASE_LOW_OFFSET(id));
740 	up_read(&cxl_dpa_rwsem);
741 
742 	port->commit_end--;
743 	cxld->flags &= ~CXL_DECODER_F_ENABLE;
744 
745 	/* Userspace is now responsible for reconfiguring this decoder */
746 	if (is_endpoint_decoder(&cxld->dev)) {
747 		struct cxl_endpoint_decoder *cxled;
748 
749 		cxled = to_cxl_endpoint_decoder(&cxld->dev);
750 		cxled->state = CXL_DECODER_STATE_MANUAL;
751 	}
752 
753 	return 0;
754 }
755 
756 static int cxl_setup_hdm_decoder_from_dvsec(
757 	struct cxl_port *port, struct cxl_decoder *cxld, u64 *dpa_base,
758 	int which, struct cxl_endpoint_dvsec_info *info)
759 {
760 	struct cxl_endpoint_decoder *cxled;
761 	u64 len;
762 	int rc;
763 
764 	if (!is_cxl_endpoint(port))
765 		return -EOPNOTSUPP;
766 
767 	cxled = to_cxl_endpoint_decoder(&cxld->dev);
768 	len = range_len(&info->dvsec_range[which]);
769 	if (!len)
770 		return -ENOENT;
771 
772 	cxld->target_type = CXL_DECODER_HOSTONLYMEM;
773 	cxld->commit = NULL;
774 	cxld->reset = NULL;
775 	cxld->hpa_range = info->dvsec_range[which];
776 
777 	/*
778 	 * Set the emulated decoder as locked pending additional support to
779 	 * change the range registers at run time.
780 	 */
781 	cxld->flags |= CXL_DECODER_F_ENABLE | CXL_DECODER_F_LOCK;
782 	port->commit_end = cxld->id;
783 
784 	rc = devm_cxl_dpa_reserve(cxled, *dpa_base, len, 0);
785 	if (rc) {
786 		dev_err(&port->dev,
787 			"decoder%d.%d: Failed to reserve DPA range %#llx - %#llx\n (%d)",
788 			port->id, cxld->id, *dpa_base, *dpa_base + len - 1, rc);
789 		return rc;
790 	}
791 	*dpa_base += len;
792 	cxled->state = CXL_DECODER_STATE_AUTO;
793 
794 	return 0;
795 }
796 
797 static int init_hdm_decoder(struct cxl_port *port, struct cxl_decoder *cxld,
798 			    int *target_map, void __iomem *hdm, int which,
799 			    u64 *dpa_base, struct cxl_endpoint_dvsec_info *info)
800 {
801 	struct cxl_endpoint_decoder *cxled = NULL;
802 	u64 size, base, skip, dpa_size, lo, hi;
803 	bool committed;
804 	u32 remainder;
805 	int i, rc;
806 	u32 ctrl;
807 	union {
808 		u64 value;
809 		unsigned char target_id[8];
810 	} target_list;
811 
812 	if (should_emulate_decoders(info))
813 		return cxl_setup_hdm_decoder_from_dvsec(port, cxld, dpa_base,
814 							which, info);
815 
816 	ctrl = readl(hdm + CXL_HDM_DECODER0_CTRL_OFFSET(which));
817 	lo = readl(hdm + CXL_HDM_DECODER0_BASE_LOW_OFFSET(which));
818 	hi = readl(hdm + CXL_HDM_DECODER0_BASE_HIGH_OFFSET(which));
819 	base = (hi << 32) + lo;
820 	lo = readl(hdm + CXL_HDM_DECODER0_SIZE_LOW_OFFSET(which));
821 	hi = readl(hdm + CXL_HDM_DECODER0_SIZE_HIGH_OFFSET(which));
822 	size = (hi << 32) + lo;
823 	committed = !!(ctrl & CXL_HDM_DECODER0_CTRL_COMMITTED);
824 	cxld->commit = cxl_decoder_commit;
825 	cxld->reset = cxl_decoder_reset;
826 
827 	if (!committed)
828 		size = 0;
829 	if (base == U64_MAX || size == U64_MAX) {
830 		dev_warn(&port->dev, "decoder%d.%d: Invalid resource range\n",
831 			 port->id, cxld->id);
832 		return -ENXIO;
833 	}
834 
835 	if (info)
836 		cxled = to_cxl_endpoint_decoder(&cxld->dev);
837 	cxld->hpa_range = (struct range) {
838 		.start = base,
839 		.end = base + size - 1,
840 	};
841 
842 	/* decoders are enabled if committed */
843 	if (committed) {
844 		cxld->flags |= CXL_DECODER_F_ENABLE;
845 		if (ctrl & CXL_HDM_DECODER0_CTRL_LOCK)
846 			cxld->flags |= CXL_DECODER_F_LOCK;
847 		if (FIELD_GET(CXL_HDM_DECODER0_CTRL_HOSTONLY, ctrl))
848 			cxld->target_type = CXL_DECODER_HOSTONLYMEM;
849 		else
850 			cxld->target_type = CXL_DECODER_DEVMEM;
851 		if (cxld->id != port->commit_end + 1) {
852 			dev_warn(&port->dev,
853 				 "decoder%d.%d: Committed out of order\n",
854 				 port->id, cxld->id);
855 			return -ENXIO;
856 		}
857 
858 		if (size == 0) {
859 			dev_warn(&port->dev,
860 				 "decoder%d.%d: Committed with zero size\n",
861 				 port->id, cxld->id);
862 			return -ENXIO;
863 		}
864 		port->commit_end = cxld->id;
865 	} else {
866 		if (cxled) {
867 			struct cxl_memdev *cxlmd = cxled_to_memdev(cxled);
868 			struct cxl_dev_state *cxlds = cxlmd->cxlds;
869 
870 			/*
871 			 * Default by devtype until a device arrives that needs
872 			 * more precision.
873 			 */
874 			if (cxlds->type == CXL_DEVTYPE_CLASSMEM)
875 				cxld->target_type = CXL_DECODER_HOSTONLYMEM;
876 			else
877 				cxld->target_type = CXL_DECODER_DEVMEM;
878 		} else {
879 			/* To be overridden by region type at commit time */
880 			cxld->target_type = CXL_DECODER_HOSTONLYMEM;
881 		}
882 
883 		if (!FIELD_GET(CXL_HDM_DECODER0_CTRL_HOSTONLY, ctrl) &&
884 		    cxld->target_type == CXL_DECODER_HOSTONLYMEM) {
885 			ctrl |= CXL_HDM_DECODER0_CTRL_HOSTONLY;
886 			writel(ctrl, hdm + CXL_HDM_DECODER0_CTRL_OFFSET(which));
887 		}
888 	}
889 	rc = eiw_to_ways(FIELD_GET(CXL_HDM_DECODER0_CTRL_IW_MASK, ctrl),
890 			  &cxld->interleave_ways);
891 	if (rc) {
892 		dev_warn(&port->dev,
893 			 "decoder%d.%d: Invalid interleave ways (ctrl: %#x)\n",
894 			 port->id, cxld->id, ctrl);
895 		return rc;
896 	}
897 	rc = eig_to_granularity(FIELD_GET(CXL_HDM_DECODER0_CTRL_IG_MASK, ctrl),
898 				 &cxld->interleave_granularity);
899 	if (rc)
900 		return rc;
901 
902 	dev_dbg(&port->dev, "decoder%d.%d: range: %#llx-%#llx iw: %d ig: %d\n",
903 		port->id, cxld->id, cxld->hpa_range.start, cxld->hpa_range.end,
904 		cxld->interleave_ways, cxld->interleave_granularity);
905 
906 	if (!cxled) {
907 		lo = readl(hdm + CXL_HDM_DECODER0_TL_LOW(which));
908 		hi = readl(hdm + CXL_HDM_DECODER0_TL_HIGH(which));
909 		target_list.value = (hi << 32) + lo;
910 		for (i = 0; i < cxld->interleave_ways; i++)
911 			target_map[i] = target_list.target_id[i];
912 
913 		return 0;
914 	}
915 
916 	if (!committed)
917 		return 0;
918 
919 	dpa_size = div_u64_rem(size, cxld->interleave_ways, &remainder);
920 	if (remainder) {
921 		dev_err(&port->dev,
922 			"decoder%d.%d: invalid committed configuration size: %#llx ways: %d\n",
923 			port->id, cxld->id, size, cxld->interleave_ways);
924 		return -ENXIO;
925 	}
926 	lo = readl(hdm + CXL_HDM_DECODER0_SKIP_LOW(which));
927 	hi = readl(hdm + CXL_HDM_DECODER0_SKIP_HIGH(which));
928 	skip = (hi << 32) + lo;
929 	rc = devm_cxl_dpa_reserve(cxled, *dpa_base + skip, dpa_size, skip);
930 	if (rc) {
931 		dev_err(&port->dev,
932 			"decoder%d.%d: Failed to reserve DPA range %#llx - %#llx\n (%d)",
933 			port->id, cxld->id, *dpa_base,
934 			*dpa_base + dpa_size + skip - 1, rc);
935 		return rc;
936 	}
937 	*dpa_base += dpa_size + skip;
938 
939 	cxled->state = CXL_DECODER_STATE_AUTO;
940 
941 	return 0;
942 }
943 
944 static void cxl_settle_decoders(struct cxl_hdm *cxlhdm)
945 {
946 	void __iomem *hdm = cxlhdm->regs.hdm_decoder;
947 	int committed, i;
948 	u32 ctrl;
949 
950 	if (!hdm)
951 		return;
952 
953 	/*
954 	 * Since the register resource was recently claimed via request_region()
955 	 * be careful about trusting the "not-committed" status until the commit
956 	 * timeout has elapsed.  The commit timeout is 10ms (CXL 2.0
957 	 * 8.2.5.12.20), but double it to be tolerant of any clock skew between
958 	 * host and target.
959 	 */
960 	for (i = 0, committed = 0; i < cxlhdm->decoder_count; i++) {
961 		ctrl = readl(hdm + CXL_HDM_DECODER0_CTRL_OFFSET(i));
962 		if (ctrl & CXL_HDM_DECODER0_CTRL_COMMITTED)
963 			committed++;
964 	}
965 
966 	/* ensure that future checks of committed can be trusted */
967 	if (committed != cxlhdm->decoder_count)
968 		msleep(20);
969 }
970 
971 /**
972  * devm_cxl_enumerate_decoders - add decoder objects per HDM register set
973  * @cxlhdm: Structure to populate with HDM capabilities
974  * @info: cached DVSEC range register info
975  */
976 int devm_cxl_enumerate_decoders(struct cxl_hdm *cxlhdm,
977 				struct cxl_endpoint_dvsec_info *info)
978 {
979 	void __iomem *hdm = cxlhdm->regs.hdm_decoder;
980 	struct cxl_port *port = cxlhdm->port;
981 	int i;
982 	u64 dpa_base = 0;
983 
984 	cxl_settle_decoders(cxlhdm);
985 
986 	for (i = 0; i < cxlhdm->decoder_count; i++) {
987 		int target_map[CXL_DECODER_MAX_INTERLEAVE] = { 0 };
988 		int rc, target_count = cxlhdm->target_count;
989 		struct cxl_decoder *cxld;
990 
991 		if (is_cxl_endpoint(port)) {
992 			struct cxl_endpoint_decoder *cxled;
993 
994 			cxled = cxl_endpoint_decoder_alloc(port);
995 			if (IS_ERR(cxled)) {
996 				dev_warn(&port->dev,
997 					 "Failed to allocate decoder%d.%d\n",
998 					 port->id, i);
999 				return PTR_ERR(cxled);
1000 			}
1001 			cxld = &cxled->cxld;
1002 		} else {
1003 			struct cxl_switch_decoder *cxlsd;
1004 
1005 			cxlsd = cxl_switch_decoder_alloc(port, target_count);
1006 			if (IS_ERR(cxlsd)) {
1007 				dev_warn(&port->dev,
1008 					 "Failed to allocate decoder%d.%d\n",
1009 					 port->id, i);
1010 				return PTR_ERR(cxlsd);
1011 			}
1012 			cxld = &cxlsd->cxld;
1013 		}
1014 
1015 		rc = init_hdm_decoder(port, cxld, target_map, hdm, i,
1016 				      &dpa_base, info);
1017 		if (rc) {
1018 			dev_warn(&port->dev,
1019 				 "Failed to initialize decoder%d.%d\n",
1020 				 port->id, i);
1021 			put_device(&cxld->dev);
1022 			return rc;
1023 		}
1024 		rc = add_hdm_decoder(port, cxld, target_map);
1025 		if (rc) {
1026 			dev_warn(&port->dev,
1027 				 "Failed to add decoder%d.%d\n", port->id, i);
1028 			return rc;
1029 		}
1030 	}
1031 
1032 	return 0;
1033 }
1034 EXPORT_SYMBOL_NS_GPL(devm_cxl_enumerate_decoders, CXL);
1035