1// SPDX-License-Identifier: GPL-2.0-only
2/* Copyright(c) 2021 Intel Corporation. All rights reserved. */
3#include <linux/platform_device.h>
4#include <linux/module.h>
5#include <linux/device.h>
6#include <linux/kernel.h>
7#include <linux/acpi.h>
8#include <linux/pci.h>
9#include <linux/node.h>
10#include <asm/div64.h>
11#include "cxlpci.h"
12#include "cxl.h"
13
14#define CXL_RCRB_SIZE SZ_8K
15
16struct cxl_cxims_data {
17 int nr_maps;
18 u64 xormaps[] __counted_by(nr_maps);
19};
20
21static const guid_t acpi_cxl_qtg_id_guid =
22 GUID_INIT(0xF365F9A6, 0xA7DE, 0x4071,
23 0xA6, 0x6A, 0xB4, 0x0C, 0x0B, 0x4F, 0x8E, 0x52);
24
25/*
26 * Find a targets entry (n) in the host bridge interleave list.
27 * CXL Specification 3.0 Table 9-22
28 */
29static int cxl_xor_calc_n(u64 hpa, struct cxl_cxims_data *cximsd, int iw,
30 int ig)
31{
32 int i = 0, n = 0;
33 u8 eiw;
34
35 /* IW: 2,4,6,8,12,16 begin building 'n' using xormaps */
36 if (iw != 3) {
37 for (i = 0; i < cximsd->nr_maps; i++)
38 n |= (hweight64(hpa & cximsd->xormaps[i]) & 1) << i;
39 }
40 /* IW: 3,6,12 add a modulo calculation to 'n' */
41 if (!is_power_of_2(n: iw)) {
42 if (ways_to_eiw(ways: iw, eiw: &eiw))
43 return -1;
44 hpa &= GENMASK_ULL(51, eiw + ig);
45 n |= do_div(hpa, 3) << i;
46 }
47 return n;
48}
49
50static struct cxl_dport *cxl_hb_xor(struct cxl_root_decoder *cxlrd, int pos)
51{
52 struct cxl_cxims_data *cximsd = cxlrd->platform_data;
53 struct cxl_switch_decoder *cxlsd = &cxlrd->cxlsd;
54 struct cxl_decoder *cxld = &cxlsd->cxld;
55 int ig = cxld->interleave_granularity;
56 int iw = cxld->interleave_ways;
57 int n = 0;
58 u64 hpa;
59
60 if (dev_WARN_ONCE(&cxld->dev,
61 cxld->interleave_ways != cxlsd->nr_targets,
62 "misconfigured root decoder\n"))
63 return NULL;
64
65 hpa = cxlrd->res->start + pos * ig;
66
67 /* Entry (n) is 0 for no interleave (iw == 1) */
68 if (iw != 1)
69 n = cxl_xor_calc_n(hpa, cximsd, iw, ig);
70
71 if (n < 0)
72 return NULL;
73
74 return cxlrd->cxlsd.target[n];
75}
76
77struct cxl_cxims_context {
78 struct device *dev;
79 struct cxl_root_decoder *cxlrd;
80};
81
82static int cxl_parse_cxims(union acpi_subtable_headers *header, void *arg,
83 const unsigned long end)
84{
85 struct acpi_cedt_cxims *cxims = (struct acpi_cedt_cxims *)header;
86 struct cxl_cxims_context *ctx = arg;
87 struct cxl_root_decoder *cxlrd = ctx->cxlrd;
88 struct cxl_decoder *cxld = &cxlrd->cxlsd.cxld;
89 struct device *dev = ctx->dev;
90 struct cxl_cxims_data *cximsd;
91 unsigned int hbig, nr_maps;
92 int rc;
93
94 rc = eig_to_granularity(eig: cxims->hbig, granularity: &hbig);
95 if (rc)
96 return rc;
97
98 /* Does this CXIMS entry apply to the given CXL Window? */
99 if (hbig != cxld->interleave_granularity)
100 return 0;
101
102 /* IW 1,3 do not use xormaps and skip this parsing entirely */
103 if (is_power_of_2(n: cxld->interleave_ways))
104 /* 2, 4, 8, 16 way */
105 nr_maps = ilog2(cxld->interleave_ways);
106 else
107 /* 6, 12 way */
108 nr_maps = ilog2(cxld->interleave_ways / 3);
109
110 if (cxims->nr_xormaps < nr_maps) {
111 dev_dbg(dev, "CXIMS nr_xormaps[%d] expected[%d]\n",
112 cxims->nr_xormaps, nr_maps);
113 return -ENXIO;
114 }
115
116 cximsd = devm_kzalloc(dev, struct_size(cximsd, xormaps, nr_maps),
117 GFP_KERNEL);
118 if (!cximsd)
119 return -ENOMEM;
120 cximsd->nr_maps = nr_maps;
121 memcpy(cximsd->xormaps, cxims->xormap_list,
122 nr_maps * sizeof(*cximsd->xormaps));
123 cxlrd->platform_data = cximsd;
124
125 return 0;
126}
127
128static unsigned long cfmws_to_decoder_flags(int restrictions)
129{
130 unsigned long flags = CXL_DECODER_F_ENABLE;
131
132 if (restrictions & ACPI_CEDT_CFMWS_RESTRICT_TYPE2)
133 flags |= CXL_DECODER_F_TYPE2;
134 if (restrictions & ACPI_CEDT_CFMWS_RESTRICT_TYPE3)
135 flags |= CXL_DECODER_F_TYPE3;
136 if (restrictions & ACPI_CEDT_CFMWS_RESTRICT_VOLATILE)
137 flags |= CXL_DECODER_F_RAM;
138 if (restrictions & ACPI_CEDT_CFMWS_RESTRICT_PMEM)
139 flags |= CXL_DECODER_F_PMEM;
140 if (restrictions & ACPI_CEDT_CFMWS_RESTRICT_FIXED)
141 flags |= CXL_DECODER_F_LOCK;
142
143 return flags;
144}
145
146static int cxl_acpi_cfmws_verify(struct device *dev,
147 struct acpi_cedt_cfmws *cfmws)
148{
149 int rc, expected_len;
150 unsigned int ways;
151
152 if (cfmws->interleave_arithmetic != ACPI_CEDT_CFMWS_ARITHMETIC_MODULO &&
153 cfmws->interleave_arithmetic != ACPI_CEDT_CFMWS_ARITHMETIC_XOR) {
154 dev_err(dev, "CFMWS Unknown Interleave Arithmetic: %d\n",
155 cfmws->interleave_arithmetic);
156 return -EINVAL;
157 }
158
159 if (!IS_ALIGNED(cfmws->base_hpa, SZ_256M)) {
160 dev_err(dev, "CFMWS Base HPA not 256MB aligned\n");
161 return -EINVAL;
162 }
163
164 if (!IS_ALIGNED(cfmws->window_size, SZ_256M)) {
165 dev_err(dev, "CFMWS Window Size not 256MB aligned\n");
166 return -EINVAL;
167 }
168
169 rc = eiw_to_ways(eiw: cfmws->interleave_ways, ways: &ways);
170 if (rc) {
171 dev_err(dev, "CFMWS Interleave Ways (%d) invalid\n",
172 cfmws->interleave_ways);
173 return -EINVAL;
174 }
175
176 expected_len = struct_size(cfmws, interleave_targets, ways);
177
178 if (cfmws->header.length < expected_len) {
179 dev_err(dev, "CFMWS length %d less than expected %d\n",
180 cfmws->header.length, expected_len);
181 return -EINVAL;
182 }
183
184 if (cfmws->header.length > expected_len)
185 dev_dbg(dev, "CFMWS length %d greater than expected %d\n",
186 cfmws->header.length, expected_len);
187
188 return 0;
189}
190
191/*
192 * Note, @dev must be the first member, see 'struct cxl_chbs_context'
193 * and mock_acpi_table_parse_cedt()
194 */
195struct cxl_cfmws_context {
196 struct device *dev;
197 struct cxl_port *root_port;
198 struct resource *cxl_res;
199 int id;
200};
201
202/**
203 * cxl_acpi_evaluate_qtg_dsm - Retrieve QTG ids via ACPI _DSM
204 * @handle: ACPI handle
205 * @coord: performance access coordinates
206 * @entries: number of QTG IDs to return
207 * @qos_class: int array provided by caller to return QTG IDs
208 *
209 * Return: number of QTG IDs returned, or -errno for errors
210 *
211 * Issue QTG _DSM with accompanied bandwidth and latency data in order to get
212 * the QTG IDs that are suitable for the performance point in order of most
213 * suitable to least suitable. Write back array of QTG IDs and return the
214 * actual number of QTG IDs written back.
215 */
216static int
217cxl_acpi_evaluate_qtg_dsm(acpi_handle handle, struct access_coordinate *coord,
218 int entries, int *qos_class)
219{
220 union acpi_object *out_obj, *out_buf, *obj;
221 union acpi_object in_array[4] = {
222 [0].integer = { ACPI_TYPE_INTEGER, coord->read_latency },
223 [1].integer = { ACPI_TYPE_INTEGER, coord->write_latency },
224 [2].integer = { ACPI_TYPE_INTEGER, coord->read_bandwidth },
225 [3].integer = { ACPI_TYPE_INTEGER, coord->write_bandwidth },
226 };
227 union acpi_object in_obj = {
228 .package = {
229 .type = ACPI_TYPE_PACKAGE,
230 .count = 4,
231 .elements = in_array,
232 },
233 };
234 int count, pkg_entries, i;
235 u16 max_qtg;
236 int rc;
237
238 if (!entries)
239 return -EINVAL;
240
241 out_obj = acpi_evaluate_dsm(handle, guid: &acpi_cxl_qtg_id_guid, rev: 1, func: 1, argv4: &in_obj);
242 if (!out_obj)
243 return -ENXIO;
244
245 if (out_obj->type != ACPI_TYPE_PACKAGE) {
246 rc = -ENXIO;
247 goto out;
248 }
249
250 /* Check Max QTG ID */
251 obj = &out_obj->package.elements[0];
252 if (obj->type != ACPI_TYPE_INTEGER) {
253 rc = -ENXIO;
254 goto out;
255 }
256
257 max_qtg = obj->integer.value;
258
259 /* It's legal to have 0 QTG entries */
260 pkg_entries = out_obj->package.count;
261 if (pkg_entries <= 1) {
262 rc = 0;
263 goto out;
264 }
265
266 /* Retrieve QTG IDs package */
267 obj = &out_obj->package.elements[1];
268 if (obj->type != ACPI_TYPE_PACKAGE) {
269 rc = -ENXIO;
270 goto out;
271 }
272
273 pkg_entries = obj->package.count;
274 count = min(entries, pkg_entries);
275 for (i = 0; i < count; i++) {
276 u16 qtg_id;
277
278 out_buf = &obj->package.elements[i];
279 if (out_buf->type != ACPI_TYPE_INTEGER) {
280 rc = -ENXIO;
281 goto out;
282 }
283
284 qtg_id = out_buf->integer.value;
285 if (qtg_id > max_qtg)
286 pr_warn("QTG ID %u greater than MAX %u\n",
287 qtg_id, max_qtg);
288
289 qos_class[i] = qtg_id;
290 }
291 rc = count;
292
293out:
294 ACPI_FREE(out_obj);
295 return rc;
296}
297
298static int cxl_acpi_qos_class(struct cxl_root *cxl_root,
299 struct access_coordinate *coord, int entries,
300 int *qos_class)
301{
302 struct device *dev = cxl_root->port.uport_dev;
303 acpi_handle handle;
304
305 if (!dev_is_platform(dev))
306 return -ENODEV;
307
308 handle = ACPI_HANDLE(dev);
309 if (!handle)
310 return -ENODEV;
311
312 return cxl_acpi_evaluate_qtg_dsm(handle, coord, entries, qos_class);
313}
314
315static const struct cxl_root_ops acpi_root_ops = {
316 .qos_class = cxl_acpi_qos_class,
317};
318
319static int __cxl_parse_cfmws(struct acpi_cedt_cfmws *cfmws,
320 struct cxl_cfmws_context *ctx)
321{
322 int target_map[CXL_DECODER_MAX_INTERLEAVE];
323 struct cxl_port *root_port = ctx->root_port;
324 struct resource *cxl_res = ctx->cxl_res;
325 struct cxl_cxims_context cxims_ctx;
326 struct cxl_root_decoder *cxlrd;
327 struct device *dev = ctx->dev;
328 cxl_calc_hb_fn cxl_calc_hb;
329 struct cxl_decoder *cxld;
330 unsigned int ways, i, ig;
331 struct resource *res;
332 int rc;
333
334 rc = cxl_acpi_cfmws_verify(dev, cfmws);
335 if (rc) {
336 dev_err(dev, "CFMWS range %#llx-%#llx not registered\n",
337 cfmws->base_hpa,
338 cfmws->base_hpa + cfmws->window_size - 1);
339 return rc;
340 }
341
342 rc = eiw_to_ways(eiw: cfmws->interleave_ways, ways: &ways);
343 if (rc)
344 return rc;
345 rc = eig_to_granularity(eig: cfmws->granularity, granularity: &ig);
346 if (rc)
347 return rc;
348 for (i = 0; i < ways; i++)
349 target_map[i] = cfmws->interleave_targets[i];
350
351 res = kzalloc(size: sizeof(*res), GFP_KERNEL);
352 if (!res)
353 return -ENOMEM;
354
355 res->name = kasprintf(GFP_KERNEL, fmt: "CXL Window %d", ctx->id++);
356 if (!res->name)
357 goto err_name;
358
359 res->start = cfmws->base_hpa;
360 res->end = cfmws->base_hpa + cfmws->window_size - 1;
361 res->flags = IORESOURCE_MEM;
362
363 /* add to the local resource tracking to establish a sort order */
364 rc = insert_resource(parent: cxl_res, new: res);
365 if (rc)
366 goto err_insert;
367
368 if (cfmws->interleave_arithmetic == ACPI_CEDT_CFMWS_ARITHMETIC_MODULO)
369 cxl_calc_hb = cxl_hb_modulo;
370 else
371 cxl_calc_hb = cxl_hb_xor;
372
373 cxlrd = cxl_root_decoder_alloc(port: root_port, nr_targets: ways, calc_hb: cxl_calc_hb);
374 if (IS_ERR(ptr: cxlrd))
375 return PTR_ERR(ptr: cxlrd);
376
377 cxld = &cxlrd->cxlsd.cxld;
378 cxld->flags = cfmws_to_decoder_flags(restrictions: cfmws->restrictions);
379 cxld->target_type = CXL_DECODER_HOSTONLYMEM;
380 cxld->hpa_range = (struct range) {
381 .start = res->start,
382 .end = res->end,
383 };
384 cxld->interleave_ways = ways;
385 /*
386 * Minimize the x1 granularity to advertise support for any
387 * valid region granularity
388 */
389 if (ways == 1)
390 ig = CXL_DECODER_MIN_GRANULARITY;
391 cxld->interleave_granularity = ig;
392
393 if (cfmws->interleave_arithmetic == ACPI_CEDT_CFMWS_ARITHMETIC_XOR) {
394 if (ways != 1 && ways != 3) {
395 cxims_ctx = (struct cxl_cxims_context) {
396 .dev = dev,
397 .cxlrd = cxlrd,
398 };
399 rc = acpi_table_parse_cedt(id: ACPI_CEDT_TYPE_CXIMS,
400 handler_arg: cxl_parse_cxims, arg: &cxims_ctx);
401 if (rc < 0)
402 goto err_xormap;
403 if (!cxlrd->platform_data) {
404 dev_err(dev, "No CXIMS for HBIG %u\n", ig);
405 rc = -EINVAL;
406 goto err_xormap;
407 }
408 }
409 }
410
411 cxlrd->qos_class = cfmws->qtg_id;
412
413 rc = cxl_decoder_add(cxld, target_map);
414err_xormap:
415 if (rc)
416 put_device(dev: &cxld->dev);
417 else
418 rc = cxl_decoder_autoremove(host: dev, cxld);
419 return rc;
420
421err_insert:
422 kfree(objp: res->name);
423err_name:
424 kfree(objp: res);
425 return -ENOMEM;
426}
427
428static int cxl_parse_cfmws(union acpi_subtable_headers *header, void *arg,
429 const unsigned long end)
430{
431 struct acpi_cedt_cfmws *cfmws = (struct acpi_cedt_cfmws *)header;
432 struct cxl_cfmws_context *ctx = arg;
433 struct device *dev = ctx->dev;
434 int rc;
435
436 rc = __cxl_parse_cfmws(cfmws, ctx);
437 if (rc)
438 dev_err(dev,
439 "Failed to add decode range: [%#llx - %#llx] (%d)\n",
440 cfmws->base_hpa,
441 cfmws->base_hpa + cfmws->window_size - 1, rc);
442 else
443 dev_dbg(dev, "decode range: node: %d range [%#llx - %#llx]\n",
444 phys_to_target_node(cfmws->base_hpa), cfmws->base_hpa,
445 cfmws->base_hpa + cfmws->window_size - 1);
446
447 /* never fail cxl_acpi load for a single window failure */
448 return 0;
449}
450
451__mock struct acpi_device *to_cxl_host_bridge(struct device *host,
452 struct device *dev)
453{
454 struct acpi_device *adev = to_acpi_device(dev);
455
456 if (!acpi_pci_find_root(handle: adev->handle))
457 return NULL;
458
459 if (strcmp(acpi_device_hid(device: adev), "ACPI0016") == 0)
460 return adev;
461 return NULL;
462}
463
464/* Note, @dev is used by mock_acpi_table_parse_cedt() */
465struct cxl_chbs_context {
466 struct device *dev;
467 unsigned long long uid;
468 resource_size_t base;
469 u32 cxl_version;
470};
471
472static int cxl_get_chbs_iter(union acpi_subtable_headers *header, void *arg,
473 const unsigned long end)
474{
475 struct cxl_chbs_context *ctx = arg;
476 struct acpi_cedt_chbs *chbs;
477
478 if (ctx->base != CXL_RESOURCE_NONE)
479 return 0;
480
481 chbs = (struct acpi_cedt_chbs *) header;
482
483 if (ctx->uid != chbs->uid)
484 return 0;
485
486 ctx->cxl_version = chbs->cxl_version;
487 if (!chbs->base)
488 return 0;
489
490 if (chbs->cxl_version == ACPI_CEDT_CHBS_VERSION_CXL11 &&
491 chbs->length != CXL_RCRB_SIZE)
492 return 0;
493
494 ctx->base = chbs->base;
495
496 return 0;
497}
498
499static int cxl_get_chbs(struct device *dev, struct acpi_device *hb,
500 struct cxl_chbs_context *ctx)
501{
502 unsigned long long uid;
503 int rc;
504
505 rc = acpi_evaluate_integer(handle: hb->handle, METHOD_NAME__UID, NULL, data: &uid);
506 if (rc != AE_OK) {
507 dev_err(dev, "unable to retrieve _UID\n");
508 return -ENOENT;
509 }
510
511 dev_dbg(dev, "UID found: %lld\n", uid);
512 *ctx = (struct cxl_chbs_context) {
513 .dev = dev,
514 .uid = uid,
515 .base = CXL_RESOURCE_NONE,
516 .cxl_version = UINT_MAX,
517 };
518
519 acpi_table_parse_cedt(id: ACPI_CEDT_TYPE_CHBS, handler_arg: cxl_get_chbs_iter, arg: ctx);
520
521 return 0;
522}
523
524static int get_genport_coordinates(struct device *dev, struct cxl_dport *dport)
525{
526 struct acpi_device *hb = to_cxl_host_bridge(NULL, dev);
527 u32 uid;
528
529 if (kstrtou32(acpi_device_uid(hb), base: 0, res: &uid))
530 return -EINVAL;
531
532 return acpi_get_genport_coordinates(uid, coord: dport->coord);
533}
534
535static int add_host_bridge_dport(struct device *match, void *arg)
536{
537 int ret;
538 acpi_status rc;
539 struct device *bridge;
540 struct cxl_dport *dport;
541 struct cxl_chbs_context ctx;
542 struct acpi_pci_root *pci_root;
543 struct cxl_port *root_port = arg;
544 struct device *host = root_port->dev.parent;
545 struct acpi_device *hb = to_cxl_host_bridge(host, dev: match);
546
547 if (!hb)
548 return 0;
549
550 rc = cxl_get_chbs(dev: match, hb, ctx: &ctx);
551 if (rc)
552 return rc;
553
554 if (ctx.cxl_version == UINT_MAX) {
555 dev_warn(match, "No CHBS found for Host Bridge (UID %lld)\n",
556 ctx.uid);
557 return 0;
558 }
559
560 if (ctx.base == CXL_RESOURCE_NONE) {
561 dev_warn(match, "CHBS invalid for Host Bridge (UID %lld)\n",
562 ctx.uid);
563 return 0;
564 }
565
566 pci_root = acpi_pci_find_root(handle: hb->handle);
567 bridge = pci_root->bus->bridge;
568
569 /*
570 * In RCH mode, bind the component regs base to the dport. In
571 * VH mode it will be bound to the CXL host bridge's port
572 * object later in add_host_bridge_uport().
573 */
574 if (ctx.cxl_version == ACPI_CEDT_CHBS_VERSION_CXL11) {
575 dev_dbg(match, "RCRB found for UID %lld: %pa\n", ctx.uid,
576 &ctx.base);
577 dport = devm_cxl_add_rch_dport(port: root_port, dport_dev: bridge, port_id: ctx.uid,
578 rcrb: ctx.base);
579 } else {
580 dport = devm_cxl_add_dport(port: root_port, dport: bridge, port_id: ctx.uid,
581 CXL_RESOURCE_NONE);
582 }
583
584 if (IS_ERR(ptr: dport))
585 return PTR_ERR(ptr: dport);
586
587 ret = get_genport_coordinates(dev: match, dport);
588 if (ret)
589 dev_dbg(match, "Failed to get generic port perf coordinates.\n");
590
591 return 0;
592}
593
594/*
595 * A host bridge is a dport to a CFMWS decode and it is a uport to the
596 * dport (PCIe Root Ports) in the host bridge.
597 */
598static int add_host_bridge_uport(struct device *match, void *arg)
599{
600 struct cxl_port *root_port = arg;
601 struct device *host = root_port->dev.parent;
602 struct acpi_device *hb = to_cxl_host_bridge(host, dev: match);
603 struct acpi_pci_root *pci_root;
604 struct cxl_dport *dport;
605 struct cxl_port *port;
606 struct device *bridge;
607 struct cxl_chbs_context ctx;
608 resource_size_t component_reg_phys;
609 int rc;
610
611 if (!hb)
612 return 0;
613
614 pci_root = acpi_pci_find_root(handle: hb->handle);
615 bridge = pci_root->bus->bridge;
616 dport = cxl_find_dport_by_dev(port: root_port, dport_dev: bridge);
617 if (!dport) {
618 dev_dbg(host, "host bridge expected and not found\n");
619 return 0;
620 }
621
622 if (dport->rch) {
623 dev_info(bridge, "host supports CXL (restricted)\n");
624 return 0;
625 }
626
627 rc = cxl_get_chbs(dev: match, hb, ctx: &ctx);
628 if (rc)
629 return rc;
630
631 if (ctx.cxl_version == ACPI_CEDT_CHBS_VERSION_CXL11) {
632 dev_warn(bridge,
633 "CXL CHBS version mismatch, skip port registration\n");
634 return 0;
635 }
636
637 component_reg_phys = ctx.base;
638 if (component_reg_phys != CXL_RESOURCE_NONE)
639 dev_dbg(match, "CHBCR found for UID %lld: %pa\n",
640 ctx.uid, &component_reg_phys);
641
642 rc = devm_cxl_register_pci_bus(host, uport_dev: bridge, bus: pci_root->bus);
643 if (rc)
644 return rc;
645
646 port = devm_cxl_add_port(host, uport_dev: bridge, component_reg_phys, parent_dport: dport);
647 if (IS_ERR(ptr: port))
648 return PTR_ERR(ptr: port);
649
650 dev_info(bridge, "host supports CXL\n");
651
652 return 0;
653}
654
655static int add_root_nvdimm_bridge(struct device *match, void *data)
656{
657 struct cxl_decoder *cxld;
658 struct cxl_port *root_port = data;
659 struct cxl_nvdimm_bridge *cxl_nvb;
660 struct device *host = root_port->dev.parent;
661
662 if (!is_root_decoder(dev: match))
663 return 0;
664
665 cxld = to_cxl_decoder(dev: match);
666 if (!(cxld->flags & CXL_DECODER_F_PMEM))
667 return 0;
668
669 cxl_nvb = devm_cxl_add_nvdimm_bridge(host, port: root_port);
670 if (IS_ERR(ptr: cxl_nvb)) {
671 dev_dbg(host, "failed to register pmem\n");
672 return PTR_ERR(ptr: cxl_nvb);
673 }
674 dev_dbg(host, "%s: add: %s\n", dev_name(&root_port->dev),
675 dev_name(&cxl_nvb->dev));
676 return 1;
677}
678
679static struct lock_class_key cxl_root_key;
680
681static void cxl_acpi_lock_reset_class(void *dev)
682{
683 device_lock_reset_class(dev);
684}
685
686static void del_cxl_resource(struct resource *res)
687{
688 kfree(objp: res->name);
689 kfree(objp: res);
690}
691
692static void cxl_set_public_resource(struct resource *priv, struct resource *pub)
693{
694 priv->desc = (unsigned long) pub;
695}
696
697static struct resource *cxl_get_public_resource(struct resource *priv)
698{
699 return (struct resource *) priv->desc;
700}
701
702static void remove_cxl_resources(void *data)
703{
704 struct resource *res, *next, *cxl = data;
705
706 for (res = cxl->child; res; res = next) {
707 struct resource *victim = cxl_get_public_resource(priv: res);
708
709 next = res->sibling;
710 remove_resource(old: res);
711
712 if (victim) {
713 remove_resource(old: victim);
714 kfree(objp: victim);
715 }
716
717 del_cxl_resource(res);
718 }
719}
720
721/**
722 * add_cxl_resources() - reflect CXL fixed memory windows in iomem_resource
723 * @cxl_res: A standalone resource tree where each CXL window is a sibling
724 *
725 * Walk each CXL window in @cxl_res and add it to iomem_resource potentially
726 * expanding its boundaries to ensure that any conflicting resources become
727 * children. If a window is expanded it may then conflict with a another window
728 * entry and require the window to be truncated or trimmed. Consider this
729 * situation:
730 *
731 * |-- "CXL Window 0" --||----- "CXL Window 1" -----|
732 * |--------------- "System RAM" -------------|
733 *
734 * ...where platform firmware has established as System RAM resource across 2
735 * windows, but has left some portion of window 1 for dynamic CXL region
736 * provisioning. In this case "Window 0" will span the entirety of the "System
737 * RAM" span, and "CXL Window 1" is truncated to the remaining tail past the end
738 * of that "System RAM" resource.
739 */
740static int add_cxl_resources(struct resource *cxl_res)
741{
742 struct resource *res, *new, *next;
743
744 for (res = cxl_res->child; res; res = next) {
745 new = kzalloc(size: sizeof(*new), GFP_KERNEL);
746 if (!new)
747 return -ENOMEM;
748 new->name = res->name;
749 new->start = res->start;
750 new->end = res->end;
751 new->flags = IORESOURCE_MEM;
752 new->desc = IORES_DESC_CXL;
753
754 /*
755 * Record the public resource in the private cxl_res tree for
756 * later removal.
757 */
758 cxl_set_public_resource(priv: res, pub: new);
759
760 insert_resource_expand_to_fit(root: &iomem_resource, new);
761
762 next = res->sibling;
763 while (next && resource_overlaps(r1: new, r2: next)) {
764 if (resource_contains(r1: new, r2: next)) {
765 struct resource *_next = next->sibling;
766
767 remove_resource(old: next);
768 del_cxl_resource(res: next);
769 next = _next;
770 } else
771 next->start = new->end + 1;
772 }
773 }
774 return 0;
775}
776
777static int pair_cxl_resource(struct device *dev, void *data)
778{
779 struct resource *cxl_res = data;
780 struct resource *p;
781
782 if (!is_root_decoder(dev))
783 return 0;
784
785 for (p = cxl_res->child; p; p = p->sibling) {
786 struct cxl_root_decoder *cxlrd = to_cxl_root_decoder(dev);
787 struct cxl_decoder *cxld = &cxlrd->cxlsd.cxld;
788 struct resource res = {
789 .start = cxld->hpa_range.start,
790 .end = cxld->hpa_range.end,
791 .flags = IORESOURCE_MEM,
792 };
793
794 if (resource_contains(r1: p, r2: &res)) {
795 cxlrd->res = cxl_get_public_resource(priv: p);
796 break;
797 }
798 }
799
800 return 0;
801}
802
803static int cxl_acpi_probe(struct platform_device *pdev)
804{
805 int rc;
806 struct resource *cxl_res;
807 struct cxl_root *cxl_root;
808 struct cxl_port *root_port;
809 struct device *host = &pdev->dev;
810 struct acpi_device *adev = ACPI_COMPANION(host);
811 struct cxl_cfmws_context ctx;
812
813 device_lock_set_class(&pdev->dev, &cxl_root_key);
814 rc = devm_add_action_or_reset(&pdev->dev, cxl_acpi_lock_reset_class,
815 &pdev->dev);
816 if (rc)
817 return rc;
818
819 cxl_res = devm_kzalloc(dev: host, size: sizeof(*cxl_res), GFP_KERNEL);
820 if (!cxl_res)
821 return -ENOMEM;
822 cxl_res->name = "CXL mem";
823 cxl_res->start = 0;
824 cxl_res->end = -1;
825 cxl_res->flags = IORESOURCE_MEM;
826
827 cxl_root = devm_cxl_add_root(host, ops: &acpi_root_ops);
828 if (IS_ERR(ptr: cxl_root))
829 return PTR_ERR(ptr: cxl_root);
830 root_port = &cxl_root->port;
831
832 rc = bus_for_each_dev(bus: adev->dev.bus, NULL, data: root_port,
833 fn: add_host_bridge_dport);
834 if (rc < 0)
835 return rc;
836
837 rc = devm_add_action_or_reset(host, remove_cxl_resources, cxl_res);
838 if (rc)
839 return rc;
840
841 ctx = (struct cxl_cfmws_context) {
842 .dev = host,
843 .root_port = root_port,
844 .cxl_res = cxl_res,
845 };
846 rc = acpi_table_parse_cedt(id: ACPI_CEDT_TYPE_CFMWS, handler_arg: cxl_parse_cfmws, arg: &ctx);
847 if (rc < 0)
848 return -ENXIO;
849
850 rc = add_cxl_resources(cxl_res);
851 if (rc)
852 return rc;
853
854 /*
855 * Populate the root decoders with their related iomem resource,
856 * if present
857 */
858 device_for_each_child(dev: &root_port->dev, data: cxl_res, fn: pair_cxl_resource);
859
860 /*
861 * Root level scanned with host-bridge as dports, now scan host-bridges
862 * for their role as CXL uports to their CXL-capable PCIe Root Ports.
863 */
864 rc = bus_for_each_dev(bus: adev->dev.bus, NULL, data: root_port,
865 fn: add_host_bridge_uport);
866 if (rc < 0)
867 return rc;
868
869 if (IS_ENABLED(CONFIG_CXL_PMEM))
870 rc = device_for_each_child(dev: &root_port->dev, data: root_port,
871 fn: add_root_nvdimm_bridge);
872 if (rc < 0)
873 return rc;
874
875 /* In case PCI is scanned before ACPI re-trigger memdev attach */
876 cxl_bus_rescan();
877 return 0;
878}
879
880static const struct acpi_device_id cxl_acpi_ids[] = {
881 { "ACPI0017" },
882 { },
883};
884MODULE_DEVICE_TABLE(acpi, cxl_acpi_ids);
885
886static const struct platform_device_id cxl_test_ids[] = {
887 { "cxl_acpi" },
888 { },
889};
890MODULE_DEVICE_TABLE(platform, cxl_test_ids);
891
892static struct platform_driver cxl_acpi_driver = {
893 .probe = cxl_acpi_probe,
894 .driver = {
895 .name = KBUILD_MODNAME,
896 .acpi_match_table = cxl_acpi_ids,
897 },
898 .id_table = cxl_test_ids,
899};
900
901static int __init cxl_acpi_init(void)
902{
903 return platform_driver_register(&cxl_acpi_driver);
904}
905
906static void __exit cxl_acpi_exit(void)
907{
908 platform_driver_unregister(&cxl_acpi_driver);
909 cxl_bus_drain();
910}
911
912/* load before dax_hmem sees 'Soft Reserved' CXL ranges */
913subsys_initcall(cxl_acpi_init);
914module_exit(cxl_acpi_exit);
915MODULE_LICENSE("GPL v2");
916MODULE_IMPORT_NS(CXL);
917MODULE_IMPORT_NS(ACPI);
918

source code of linux/drivers/cxl/acpi.c