1 // SPDX-License-Identifier: GPL-2.0
2 /*
3 * Firmware replacement code.
4 *
5 * Work around broken BIOSes that don't set an aperture, only set the
6 * aperture in the AGP bridge, or set too small aperture.
7 *
8 * If all fails map the aperture over some low memory. This is cheaper than
9 * doing bounce buffering. The memory is lost. This is done at early boot
10 * because only the bootmem allocator can allocate 32+MB.
11 *
12 * Copyright 2002 Andi Kleen, SuSE Labs.
13 */
14 #define pr_fmt(fmt) "AGP: " fmt
15
16 #include <linux/kernel.h>
17 #include <linux/kcore.h>
18 #include <linux/types.h>
19 #include <linux/init.h>
20 #include <linux/memblock.h>
21 #include <linux/mmzone.h>
22 #include <linux/pci_ids.h>
23 #include <linux/pci.h>
24 #include <linux/bitops.h>
25 #include <linux/suspend.h>
26 #include <asm/e820/api.h>
27 #include <asm/io.h>
28 #include <asm/iommu.h>
29 #include <asm/gart.h>
30 #include <asm/pci-direct.h>
31 #include <asm/dma.h>
32 #include <asm/amd_nb.h>
33 #include <asm/x86_init.h>
34 #include <linux/crash_dump.h>
35
36 /*
37 * Using 512M as goal, in case kexec will load kernel_big
38 * that will do the on-position decompress, and could overlap with
39 * the gart aperture that is used.
40 * Sequence:
41 * kernel_small
42 * ==> kexec (with kdump trigger path or gart still enabled)
43 * ==> kernel_small (gart area become e820_reserved)
44 * ==> kexec (with kdump trigger path or gart still enabled)
45 * ==> kerne_big (uncompressed size will be big than 64M or 128M)
46 * So don't use 512M below as gart iommu, leave the space for kernel
47 * code for safe.
48 */
49 #define GART_MIN_ADDR (512ULL << 20)
50 #define GART_MAX_ADDR (1ULL << 32)
51
52 int gart_iommu_aperture;
53 int gart_iommu_aperture_disabled __initdata;
54 int gart_iommu_aperture_allowed __initdata;
55
56 int fallback_aper_order __initdata = 1; /* 64MB */
57 int fallback_aper_force __initdata;
58
59 int fix_aperture __initdata = 1;
60
61 #if defined(CONFIG_PROC_VMCORE) || defined(CONFIG_PROC_KCORE)
62 /*
63 * If the first kernel maps the aperture over e820 RAM, the kdump kernel will
64 * use the same range because it will remain configured in the northbridge.
65 * Trying to dump this area via /proc/vmcore may crash the machine, so exclude
66 * it from vmcore.
67 */
68 static unsigned long aperture_pfn_start, aperture_page_count;
69
gart_mem_pfn_is_ram(unsigned long pfn)70 static int gart_mem_pfn_is_ram(unsigned long pfn)
71 {
72 return likely((pfn < aperture_pfn_start) ||
73 (pfn >= aperture_pfn_start + aperture_page_count));
74 }
75
76 #ifdef CONFIG_PROC_VMCORE
gart_oldmem_pfn_is_ram(struct vmcore_cb * cb,unsigned long pfn)77 static bool gart_oldmem_pfn_is_ram(struct vmcore_cb *cb, unsigned long pfn)
78 {
79 return !!gart_mem_pfn_is_ram(pfn);
80 }
81
82 static struct vmcore_cb gart_vmcore_cb = {
83 .pfn_is_ram = gart_oldmem_pfn_is_ram,
84 };
85 #endif
86
exclude_from_core(u64 aper_base,u32 aper_order)87 static void __init exclude_from_core(u64 aper_base, u32 aper_order)
88 {
89 aperture_pfn_start = aper_base >> PAGE_SHIFT;
90 aperture_page_count = (32 * 1024 * 1024) << aper_order >> PAGE_SHIFT;
91 #ifdef CONFIG_PROC_VMCORE
92 register_vmcore_cb(&gart_vmcore_cb);
93 #endif
94 #ifdef CONFIG_PROC_KCORE
95 WARN_ON(register_mem_pfn_is_ram(&gart_mem_pfn_is_ram));
96 #endif
97 }
98 #else
exclude_from_core(u64 aper_base,u32 aper_order)99 static void exclude_from_core(u64 aper_base, u32 aper_order)
100 {
101 }
102 #endif
103
104 /* This code runs before the PCI subsystem is initialized, so just
105 access the northbridge directly. */
106
allocate_aperture(void)107 static u32 __init allocate_aperture(void)
108 {
109 u32 aper_size;
110 unsigned long addr;
111
112 /* aper_size should <= 1G */
113 if (fallback_aper_order > 5)
114 fallback_aper_order = 5;
115 aper_size = (32 * 1024 * 1024) << fallback_aper_order;
116
117 /*
118 * Aperture has to be naturally aligned. This means a 2GB aperture
119 * won't have much chance of finding a place in the lower 4GB of
120 * memory. Unfortunately we cannot move it up because that would
121 * make the IOMMU useless.
122 */
123 addr = memblock_phys_alloc_range(aper_size, aper_size,
124 GART_MIN_ADDR, GART_MAX_ADDR);
125 if (!addr) {
126 pr_err("Cannot allocate aperture memory hole [mem %#010lx-%#010lx] (%uKB)\n",
127 addr, addr + aper_size - 1, aper_size >> 10);
128 return 0;
129 }
130 pr_info("Mapping aperture over RAM [mem %#010lx-%#010lx] (%uKB)\n",
131 addr, addr + aper_size - 1, aper_size >> 10);
132 register_nosave_region(addr >> PAGE_SHIFT,
133 (addr+aper_size) >> PAGE_SHIFT);
134
135 return (u32)addr;
136 }
137
138
139 /* Find a PCI capability */
find_cap(int bus,int slot,int func,int cap)140 static u32 __init find_cap(int bus, int slot, int func, int cap)
141 {
142 int bytes;
143 u8 pos;
144
145 if (!(read_pci_config_16(bus, slot, func, PCI_STATUS) &
146 PCI_STATUS_CAP_LIST))
147 return 0;
148
149 pos = read_pci_config_byte(bus, slot, func, PCI_CAPABILITY_LIST);
150 for (bytes = 0; bytes < 48 && pos >= 0x40; bytes++) {
151 u8 id;
152
153 pos &= ~3;
154 id = read_pci_config_byte(bus, slot, func, pos+PCI_CAP_LIST_ID);
155 if (id == 0xff)
156 break;
157 if (id == cap)
158 return pos;
159 pos = read_pci_config_byte(bus, slot, func,
160 pos+PCI_CAP_LIST_NEXT);
161 }
162 return 0;
163 }
164
165 /* Read a standard AGPv3 bridge header */
read_agp(int bus,int slot,int func,int cap,u32 * order)166 static u32 __init read_agp(int bus, int slot, int func, int cap, u32 *order)
167 {
168 u32 apsize;
169 u32 apsizereg;
170 int nbits;
171 u32 aper_low, aper_hi;
172 u64 aper;
173 u32 old_order;
174
175 pr_info("pci 0000:%02x:%02x:%02x: AGP bridge\n", bus, slot, func);
176 apsizereg = read_pci_config_16(bus, slot, func, cap + 0x14);
177 if (apsizereg == 0xffffffff) {
178 pr_err("pci 0000:%02x:%02x.%d: APSIZE unreadable\n",
179 bus, slot, func);
180 return 0;
181 }
182
183 /* old_order could be the value from NB gart setting */
184 old_order = *order;
185
186 apsize = apsizereg & 0xfff;
187 /* Some BIOS use weird encodings not in the AGPv3 table. */
188 if (apsize & 0xff)
189 apsize |= 0xf00;
190 nbits = hweight16(apsize);
191 *order = 7 - nbits;
192 if ((int)*order < 0) /* < 32MB */
193 *order = 0;
194
195 aper_low = read_pci_config(bus, slot, func, 0x10);
196 aper_hi = read_pci_config(bus, slot, func, 0x14);
197 aper = (aper_low & ~((1<<22)-1)) | ((u64)aper_hi << 32);
198
199 /*
200 * On some sick chips, APSIZE is 0. It means it wants 4G
201 * so let double check that order, and lets trust AMD NB settings:
202 */
203 pr_info("pci 0000:%02x:%02x.%d: AGP aperture [bus addr %#010Lx-%#010Lx] (old size %uMB)\n",
204 bus, slot, func, aper, aper + (32ULL << (old_order + 20)) - 1,
205 32 << old_order);
206 if (aper + (32ULL<<(20 + *order)) > 0x100000000ULL) {
207 pr_info("pci 0000:%02x:%02x.%d: AGP aperture size %uMB (APSIZE %#x) is not right, using settings from NB\n",
208 bus, slot, func, 32 << *order, apsizereg);
209 *order = old_order;
210 }
211
212 pr_info("pci 0000:%02x:%02x.%d: AGP aperture [bus addr %#010Lx-%#010Lx] (%uMB, APSIZE %#x)\n",
213 bus, slot, func, aper, aper + (32ULL << (*order + 20)) - 1,
214 32 << *order, apsizereg);
215
216 if (!aperture_valid(aper, (32*1024*1024) << *order, 32<<20))
217 return 0;
218 return (u32)aper;
219 }
220
221 /*
222 * Look for an AGP bridge. Windows only expects the aperture in the
223 * AGP bridge and some BIOS forget to initialize the Northbridge too.
224 * Work around this here.
225 *
226 * Do an PCI bus scan by hand because we're running before the PCI
227 * subsystem.
228 *
229 * All AMD AGP bridges are AGPv3 compliant, so we can do this scan
230 * generically. It's probably overkill to always scan all slots because
231 * the AGP bridges should be always an own bus on the HT hierarchy,
232 * but do it here for future safety.
233 */
search_agp_bridge(u32 * order,int * valid_agp)234 static u32 __init search_agp_bridge(u32 *order, int *valid_agp)
235 {
236 int bus, slot, func;
237
238 /* Poor man's PCI discovery */
239 for (bus = 0; bus < 256; bus++) {
240 for (slot = 0; slot < 32; slot++) {
241 for (func = 0; func < 8; func++) {
242 u32 class, cap;
243 u8 type;
244 class = read_pci_config(bus, slot, func,
245 PCI_CLASS_REVISION);
246 if (class == 0xffffffff)
247 break;
248
249 switch (class >> 16) {
250 case PCI_CLASS_BRIDGE_HOST:
251 case PCI_CLASS_BRIDGE_OTHER: /* needed? */
252 /* AGP bridge? */
253 cap = find_cap(bus, slot, func,
254 PCI_CAP_ID_AGP);
255 if (!cap)
256 break;
257 *valid_agp = 1;
258 return read_agp(bus, slot, func, cap,
259 order);
260 }
261
262 type = read_pci_config_byte(bus, slot, func,
263 PCI_HEADER_TYPE);
264 if (!(type & PCI_HEADER_TYPE_MFD))
265 break;
266 }
267 }
268 }
269 pr_info("No AGP bridge found\n");
270
271 return 0;
272 }
273
274 static bool gart_fix_e820 __initdata = true;
275
parse_gart_mem(char * p)276 static int __init parse_gart_mem(char *p)
277 {
278 return kstrtobool(p, &gart_fix_e820);
279 }
280 early_param("gart_fix_e820", parse_gart_mem);
281
282 /*
283 * With kexec/kdump, if the first kernel doesn't shut down the GART and the
284 * second kernel allocates a different GART region, there might be two
285 * overlapping GART regions present:
286 *
287 * - the first still used by the GART initialized in the first kernel.
288 * - (sub-)set of it used as normal RAM by the second kernel.
289 *
290 * which leads to memory corruptions and a kernel panic eventually.
291 *
292 * This can also happen if the BIOS has forgotten to mark the GART region
293 * as reserved.
294 *
295 * Try to update the e820 map to mark that new region as reserved.
296 */
early_gart_iommu_check(void)297 void __init early_gart_iommu_check(void)
298 {
299 u32 agp_aper_order = 0;
300 int i, fix, slot, valid_agp = 0;
301 u32 ctl;
302 u32 aper_size = 0, aper_order = 0, last_aper_order = 0;
303 u64 aper_base = 0, last_aper_base = 0;
304 int aper_enabled = 0, last_aper_enabled = 0, last_valid = 0;
305
306 if (!amd_gart_present())
307 return;
308
309 if (!early_pci_allowed())
310 return;
311
312 /* This is mostly duplicate of iommu_hole_init */
313 search_agp_bridge(&agp_aper_order, &valid_agp);
314
315 fix = 0;
316 for (i = 0; amd_nb_bus_dev_ranges[i].dev_limit; i++) {
317 int bus;
318 int dev_base, dev_limit;
319
320 bus = amd_nb_bus_dev_ranges[i].bus;
321 dev_base = amd_nb_bus_dev_ranges[i].dev_base;
322 dev_limit = amd_nb_bus_dev_ranges[i].dev_limit;
323
324 for (slot = dev_base; slot < dev_limit; slot++) {
325 if (!early_is_amd_nb(read_pci_config(bus, slot, 3, 0x00)))
326 continue;
327
328 ctl = read_pci_config(bus, slot, 3, AMD64_GARTAPERTURECTL);
329 aper_enabled = ctl & GARTEN;
330 aper_order = (ctl >> 1) & 7;
331 aper_size = (32 * 1024 * 1024) << aper_order;
332 aper_base = read_pci_config(bus, slot, 3, AMD64_GARTAPERTUREBASE) & 0x7fff;
333 aper_base <<= 25;
334
335 if (last_valid) {
336 if ((aper_order != last_aper_order) ||
337 (aper_base != last_aper_base) ||
338 (aper_enabled != last_aper_enabled)) {
339 fix = 1;
340 break;
341 }
342 }
343
344 last_aper_order = aper_order;
345 last_aper_base = aper_base;
346 last_aper_enabled = aper_enabled;
347 last_valid = 1;
348 }
349 }
350
351 if (!fix && !aper_enabled)
352 return;
353
354 if (!aper_base || !aper_size || aper_base + aper_size > 0x100000000UL)
355 fix = 1;
356
357 if (gart_fix_e820 && !fix && aper_enabled) {
358 if (e820__mapped_any(aper_base, aper_base + aper_size,
359 E820_TYPE_RAM)) {
360 /* reserve it, so we can reuse it in second kernel */
361 pr_info("e820: reserve [mem %#010Lx-%#010Lx] for GART\n",
362 aper_base, aper_base + aper_size - 1);
363 e820__range_add(aper_base, aper_size, E820_TYPE_RESERVED);
364 e820__update_table_print();
365 }
366 }
367
368 if (valid_agp)
369 return;
370
371 /* disable them all at first */
372 for (i = 0; i < amd_nb_bus_dev_ranges[i].dev_limit; i++) {
373 int bus;
374 int dev_base, dev_limit;
375
376 bus = amd_nb_bus_dev_ranges[i].bus;
377 dev_base = amd_nb_bus_dev_ranges[i].dev_base;
378 dev_limit = amd_nb_bus_dev_ranges[i].dev_limit;
379
380 for (slot = dev_base; slot < dev_limit; slot++) {
381 if (!early_is_amd_nb(read_pci_config(bus, slot, 3, 0x00)))
382 continue;
383
384 ctl = read_pci_config(bus, slot, 3, AMD64_GARTAPERTURECTL);
385 ctl &= ~GARTEN;
386 write_pci_config(bus, slot, 3, AMD64_GARTAPERTURECTL, ctl);
387 }
388 }
389
390 }
391
392 static int __initdata printed_gart_size_msg;
393
gart_iommu_hole_init(void)394 void __init gart_iommu_hole_init(void)
395 {
396 u32 agp_aper_base = 0, agp_aper_order = 0;
397 u32 aper_size, aper_alloc = 0, aper_order = 0, last_aper_order = 0;
398 u64 aper_base, last_aper_base = 0;
399 int fix, slot, valid_agp = 0;
400 int i, node;
401
402 if (!amd_gart_present())
403 return;
404
405 if (gart_iommu_aperture_disabled || !fix_aperture ||
406 !early_pci_allowed())
407 return;
408
409 pr_info("Checking aperture...\n");
410
411 if (!fallback_aper_force)
412 agp_aper_base = search_agp_bridge(&agp_aper_order, &valid_agp);
413
414 fix = 0;
415 node = 0;
416 for (i = 0; i < amd_nb_bus_dev_ranges[i].dev_limit; i++) {
417 int bus;
418 int dev_base, dev_limit;
419 u32 ctl;
420
421 bus = amd_nb_bus_dev_ranges[i].bus;
422 dev_base = amd_nb_bus_dev_ranges[i].dev_base;
423 dev_limit = amd_nb_bus_dev_ranges[i].dev_limit;
424
425 for (slot = dev_base; slot < dev_limit; slot++) {
426 if (!early_is_amd_nb(read_pci_config(bus, slot, 3, 0x00)))
427 continue;
428
429 iommu_detected = 1;
430 gart_iommu_aperture = 1;
431 x86_init.iommu.iommu_init = gart_iommu_init;
432
433 ctl = read_pci_config(bus, slot, 3,
434 AMD64_GARTAPERTURECTL);
435
436 /*
437 * Before we do anything else disable the GART. It may
438 * still be enabled if we boot into a crash-kernel here.
439 * Reconfiguring the GART while it is enabled could have
440 * unknown side-effects.
441 */
442 ctl &= ~GARTEN;
443 write_pci_config(bus, slot, 3, AMD64_GARTAPERTURECTL, ctl);
444
445 aper_order = (ctl >> 1) & 7;
446 aper_size = (32 * 1024 * 1024) << aper_order;
447 aper_base = read_pci_config(bus, slot, 3, AMD64_GARTAPERTUREBASE) & 0x7fff;
448 aper_base <<= 25;
449
450 pr_info("Node %d: aperture [bus addr %#010Lx-%#010Lx] (%uMB)\n",
451 node, aper_base, aper_base + aper_size - 1,
452 aper_size >> 20);
453 node++;
454
455 if (!aperture_valid(aper_base, aper_size, 64<<20)) {
456 if (valid_agp && agp_aper_base &&
457 agp_aper_base == aper_base &&
458 agp_aper_order == aper_order) {
459 /* the same between two setting from NB and agp */
460 if (!no_iommu &&
461 max_pfn > MAX_DMA32_PFN &&
462 !printed_gart_size_msg) {
463 pr_err("you are using iommu with agp, but GART size is less than 64MB\n");
464 pr_err("please increase GART size in your BIOS setup\n");
465 pr_err("if BIOS doesn't have that option, contact your HW vendor!\n");
466 printed_gart_size_msg = 1;
467 }
468 } else {
469 fix = 1;
470 goto out;
471 }
472 }
473
474 if ((last_aper_order && aper_order != last_aper_order) ||
475 (last_aper_base && aper_base != last_aper_base)) {
476 fix = 1;
477 goto out;
478 }
479 last_aper_order = aper_order;
480 last_aper_base = aper_base;
481 }
482 }
483
484 out:
485 if (!fix && !fallback_aper_force) {
486 if (last_aper_base) {
487 /*
488 * If this is the kdump kernel, the first kernel
489 * may have allocated the range over its e820 RAM
490 * and fixed up the northbridge
491 */
492 exclude_from_core(last_aper_base, last_aper_order);
493 }
494 return;
495 }
496
497 if (!fallback_aper_force) {
498 aper_alloc = agp_aper_base;
499 aper_order = agp_aper_order;
500 }
501
502 if (aper_alloc) {
503 /* Got the aperture from the AGP bridge */
504 } else if ((!no_iommu && max_pfn > MAX_DMA32_PFN) ||
505 force_iommu ||
506 valid_agp ||
507 fallback_aper_force) {
508 pr_info("Your BIOS doesn't leave an aperture memory hole\n");
509 pr_info("Please enable the IOMMU option in the BIOS setup\n");
510 pr_info("This costs you %dMB of RAM\n",
511 32 << fallback_aper_order);
512
513 aper_order = fallback_aper_order;
514 aper_alloc = allocate_aperture();
515 if (!aper_alloc) {
516 /*
517 * Could disable AGP and IOMMU here, but it's
518 * probably not worth it. But the later users
519 * cannot deal with bad apertures and turning
520 * on the aperture over memory causes very
521 * strange problems, so it's better to panic
522 * early.
523 */
524 panic("Not enough memory for aperture");
525 }
526 } else {
527 return;
528 }
529
530 /*
531 * If this is the kdump kernel _and_ the first kernel did not
532 * configure the aperture in the northbridge, this range may
533 * overlap with the first kernel's memory. We can't access the
534 * range through vmcore even though it should be part of the dump.
535 */
536 exclude_from_core(aper_alloc, aper_order);
537
538 /* Fix up the north bridges */
539 for (i = 0; i < amd_nb_bus_dev_ranges[i].dev_limit; i++) {
540 int bus, dev_base, dev_limit;
541
542 /*
543 * Don't enable translation yet but enable GART IO and CPU
544 * accesses and set DISTLBWALKPRB since GART table memory is UC.
545 */
546 u32 ctl = aper_order << 1;
547
548 bus = amd_nb_bus_dev_ranges[i].bus;
549 dev_base = amd_nb_bus_dev_ranges[i].dev_base;
550 dev_limit = amd_nb_bus_dev_ranges[i].dev_limit;
551 for (slot = dev_base; slot < dev_limit; slot++) {
552 if (!early_is_amd_nb(read_pci_config(bus, slot, 3, 0x00)))
553 continue;
554
555 write_pci_config(bus, slot, 3, AMD64_GARTAPERTURECTL, ctl);
556 write_pci_config(bus, slot, 3, AMD64_GARTAPERTUREBASE, aper_alloc >> 25);
557 }
558 }
559
560 set_up_gart_resume(aper_order, aper_alloc);
561 }
562