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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/types.h>
18#include <linux/init.h>
19#include <linux/memblock.h>
20#include <linux/mmzone.h>
21#include <linux/pci_ids.h>
22#include <linux/pci.h>
23#include <linux/bitops.h>
24#include <linux/suspend.h>
25#include <asm/e820/api.h>
26#include <asm/io.h>
27#include <asm/iommu.h>
28#include <asm/gart.h>
29#include <asm/pci-direct.h>
30#include <asm/dma.h>
31#include <asm/amd_nb.h>
32#include <asm/x86_init.h>
33#include <linux/crash_dump.h>
34
35/*
36 * Using 512M as goal, in case kexec will load kernel_big
37 * that will do the on-position decompress, and could overlap with
38 * with the gart aperture that is used.
39 * Sequence:
40 * kernel_small
41 * ==> kexec (with kdump trigger path or gart still enabled)
42 * ==> kernel_small (gart area become e820_reserved)
43 * ==> kexec (with kdump trigger path or gart still enabled)
44 * ==> kerne_big (uncompressed size will be big than 64M or 128M)
45 * So don't use 512M below as gart iommu, leave the space for kernel
46 * code for safe.
47 */
48#define GART_MIN_ADDR (512ULL << 20)
49#define GART_MAX_ADDR (1ULL << 32)
50
51int gart_iommu_aperture;
52int gart_iommu_aperture_disabled __initdata;
53int gart_iommu_aperture_allowed __initdata;
54
55int fallback_aper_order __initdata = 1; /* 64MB */
56int fallback_aper_force __initdata;
57
58int fix_aperture __initdata = 1;
59
60#ifdef CONFIG_PROC_VMCORE
61/*
62 * If the first kernel maps the aperture over e820 RAM, the kdump kernel will
63 * use the same range because it will remain configured in the northbridge.
64 * Trying to dump this area via /proc/vmcore may crash the machine, so exclude
65 * it from vmcore.
66 */
67static unsigned long aperture_pfn_start, aperture_page_count;
68
69static int gart_oldmem_pfn_is_ram(unsigned long pfn)
70{
71 return likely((pfn < aperture_pfn_start) ||
72 (pfn >= aperture_pfn_start + aperture_page_count));
73}
74
75static void exclude_from_vmcore(u64 aper_base, u32 aper_order)
76{
77 aperture_pfn_start = aper_base >> PAGE_SHIFT;
78 aperture_page_count = (32 * 1024 * 1024) << aper_order >> PAGE_SHIFT;
79 WARN_ON(register_oldmem_pfn_is_ram(&gart_oldmem_pfn_is_ram));
80}
81#else
82static void exclude_from_vmcore(u64 aper_base, u32 aper_order)
83{
84}
85#endif
86
87/* This code runs before the PCI subsystem is initialized, so just
88 access the northbridge directly. */
89
90static u32 __init allocate_aperture(void)
91{
92 u32 aper_size;
93 unsigned long addr;
94
95 /* aper_size should <= 1G */
96 if (fallback_aper_order > 5)
97 fallback_aper_order = 5;
98 aper_size = (32 * 1024 * 1024) << fallback_aper_order;
99
100 /*
101 * Aperture has to be naturally aligned. This means a 2GB aperture
102 * won't have much chance of finding a place in the lower 4GB of
103 * memory. Unfortunately we cannot move it up because that would
104 * make the IOMMU useless.
105 */
106 addr = memblock_find_in_range(GART_MIN_ADDR, GART_MAX_ADDR,
107 aper_size, aper_size);
108 if (!addr) {
109 pr_err("Cannot allocate aperture memory hole [mem %#010lx-%#010lx] (%uKB)\n",
110 addr, addr + aper_size - 1, aper_size >> 10);
111 return 0;
112 }
113 memblock_reserve(addr, aper_size);
114 pr_info("Mapping aperture over RAM [mem %#010lx-%#010lx] (%uKB)\n",
115 addr, addr + aper_size - 1, aper_size >> 10);
116 register_nosave_region(addr >> PAGE_SHIFT,
117 (addr+aper_size) >> PAGE_SHIFT);
118
119 return (u32)addr;
120}
121
122
123/* Find a PCI capability */
124static u32 __init find_cap(int bus, int slot, int func, int cap)
125{
126 int bytes;
127 u8 pos;
128
129 if (!(read_pci_config_16(bus, slot, func, PCI_STATUS) &
130 PCI_STATUS_CAP_LIST))
131 return 0;
132
133 pos = read_pci_config_byte(bus, slot, func, PCI_CAPABILITY_LIST);
134 for (bytes = 0; bytes < 48 && pos >= 0x40; bytes++) {
135 u8 id;
136
137 pos &= ~3;
138 id = read_pci_config_byte(bus, slot, func, pos+PCI_CAP_LIST_ID);
139 if (id == 0xff)
140 break;
141 if (id == cap)
142 return pos;
143 pos = read_pci_config_byte(bus, slot, func,
144 pos+PCI_CAP_LIST_NEXT);
145 }
146 return 0;
147}
148
149/* Read a standard AGPv3 bridge header */
150static u32 __init read_agp(int bus, int slot, int func, int cap, u32 *order)
151{
152 u32 apsize;
153 u32 apsizereg;
154 int nbits;
155 u32 aper_low, aper_hi;
156 u64 aper;
157 u32 old_order;
158
159 pr_info("pci 0000:%02x:%02x:%02x: AGP bridge\n", bus, slot, func);
160 apsizereg = read_pci_config_16(bus, slot, func, cap + 0x14);
161 if (apsizereg == 0xffffffff) {
162 pr_err("pci 0000:%02x:%02x.%d: APSIZE unreadable\n",
163 bus, slot, func);
164 return 0;
165 }
166
167 /* old_order could be the value from NB gart setting */
168 old_order = *order;
169
170 apsize = apsizereg & 0xfff;
171 /* Some BIOS use weird encodings not in the AGPv3 table. */
172 if (apsize & 0xff)
173 apsize |= 0xf00;
174 nbits = hweight16(apsize);
175 *order = 7 - nbits;
176 if ((int)*order < 0) /* < 32MB */
177 *order = 0;
178
179 aper_low = read_pci_config(bus, slot, func, 0x10);
180 aper_hi = read_pci_config(bus, slot, func, 0x14);
181 aper = (aper_low & ~((1<<22)-1)) | ((u64)aper_hi << 32);
182
183 /*
184 * On some sick chips, APSIZE is 0. It means it wants 4G
185 * so let double check that order, and lets trust AMD NB settings:
186 */
187 pr_info("pci 0000:%02x:%02x.%d: AGP aperture [bus addr %#010Lx-%#010Lx] (old size %uMB)\n",
188 bus, slot, func, aper, aper + (32ULL << (old_order + 20)) - 1,
189 32 << old_order);
190 if (aper + (32ULL<<(20 + *order)) > 0x100000000ULL) {
191 pr_info("pci 0000:%02x:%02x.%d: AGP aperture size %uMB (APSIZE %#x) is not right, using settings from NB\n",
192 bus, slot, func, 32 << *order, apsizereg);
193 *order = old_order;
194 }
195
196 pr_info("pci 0000:%02x:%02x.%d: AGP aperture [bus addr %#010Lx-%#010Lx] (%uMB, APSIZE %#x)\n",
197 bus, slot, func, aper, aper + (32ULL << (*order + 20)) - 1,
198 32 << *order, apsizereg);
199
200 if (!aperture_valid(aper, (32*1024*1024) << *order, 32<<20))
201 return 0;
202 return (u32)aper;
203}
204
205/*
206 * Look for an AGP bridge. Windows only expects the aperture in the
207 * AGP bridge and some BIOS forget to initialize the Northbridge too.
208 * Work around this here.
209 *
210 * Do an PCI bus scan by hand because we're running before the PCI
211 * subsystem.
212 *
213 * All AMD AGP bridges are AGPv3 compliant, so we can do this scan
214 * generically. It's probably overkill to always scan all slots because
215 * the AGP bridges should be always an own bus on the HT hierarchy,
216 * but do it here for future safety.
217 */
218static u32 __init search_agp_bridge(u32 *order, int *valid_agp)
219{
220 int bus, slot, func;
221
222 /* Poor man's PCI discovery */
223 for (bus = 0; bus < 256; bus++) {
224 for (slot = 0; slot < 32; slot++) {
225 for (func = 0; func < 8; func++) {
226 u32 class, cap;
227 u8 type;
228 class = read_pci_config(bus, slot, func,
229 PCI_CLASS_REVISION);
230 if (class == 0xffffffff)
231 break;
232
233 switch (class >> 16) {
234 case PCI_CLASS_BRIDGE_HOST:
235 case PCI_CLASS_BRIDGE_OTHER: /* needed? */
236 /* AGP bridge? */
237 cap = find_cap(bus, slot, func,
238 PCI_CAP_ID_AGP);
239 if (!cap)
240 break;
241 *valid_agp = 1;
242 return read_agp(bus, slot, func, cap,
243 order);
244 }
245
246 /* No multi-function device? */
247 type = read_pci_config_byte(bus, slot, func,
248 PCI_HEADER_TYPE);
249 if (!(type & 0x80))
250 break;
251 }
252 }
253 }
254 pr_info("No AGP bridge found\n");
255
256 return 0;
257}
258
259static bool gart_fix_e820 __initdata = true;
260
261static int __init parse_gart_mem(char *p)
262{
263 return kstrtobool(p, &gart_fix_e820);
264}
265early_param("gart_fix_e820", parse_gart_mem);
266
267void __init early_gart_iommu_check(void)
268{
269 /*
270 * in case it is enabled before, esp for kexec/kdump,
271 * previous kernel already enable that. memset called
272 * by allocate_aperture/__alloc_bootmem_nopanic cause restart.
273 * or second kernel have different position for GART hole. and new
274 * kernel could use hole as RAM that is still used by GART set by
275 * first kernel
276 * or BIOS forget to put that in reserved.
277 * try to update e820 to make that region as reserved.
278 */
279 u32 agp_aper_order = 0;
280 int i, fix, slot, valid_agp = 0;
281 u32 ctl;
282 u32 aper_size = 0, aper_order = 0, last_aper_order = 0;
283 u64 aper_base = 0, last_aper_base = 0;
284 int aper_enabled = 0, last_aper_enabled = 0, last_valid = 0;
285
286 if (!amd_gart_present())
287 return;
288
289 if (!early_pci_allowed())
290 return;
291
292 /* This is mostly duplicate of iommu_hole_init */
293 search_agp_bridge(&agp_aper_order, &valid_agp);
294
295 fix = 0;
296 for (i = 0; amd_nb_bus_dev_ranges[i].dev_limit; i++) {
297 int bus;
298 int dev_base, dev_limit;
299
300 bus = amd_nb_bus_dev_ranges[i].bus;
301 dev_base = amd_nb_bus_dev_ranges[i].dev_base;
302 dev_limit = amd_nb_bus_dev_ranges[i].dev_limit;
303
304 for (slot = dev_base; slot < dev_limit; slot++) {
305 if (!early_is_amd_nb(read_pci_config(bus, slot, 3, 0x00)))
306 continue;
307
308 ctl = read_pci_config(bus, slot, 3, AMD64_GARTAPERTURECTL);
309 aper_enabled = ctl & GARTEN;
310 aper_order = (ctl >> 1) & 7;
311 aper_size = (32 * 1024 * 1024) << aper_order;
312 aper_base = read_pci_config(bus, slot, 3, AMD64_GARTAPERTUREBASE) & 0x7fff;
313 aper_base <<= 25;
314
315 if (last_valid) {
316 if ((aper_order != last_aper_order) ||
317 (aper_base != last_aper_base) ||
318 (aper_enabled != last_aper_enabled)) {
319 fix = 1;
320 break;
321 }
322 }
323
324 last_aper_order = aper_order;
325 last_aper_base = aper_base;
326 last_aper_enabled = aper_enabled;
327 last_valid = 1;
328 }
329 }
330
331 if (!fix && !aper_enabled)
332 return;
333
334 if (!aper_base || !aper_size || aper_base + aper_size > 0x100000000UL)
335 fix = 1;
336
337 if (gart_fix_e820 && !fix && aper_enabled) {
338 if (e820__mapped_any(aper_base, aper_base + aper_size,
339 E820_TYPE_RAM)) {
340 /* reserve it, so we can reuse it in second kernel */
341 pr_info("e820: reserve [mem %#010Lx-%#010Lx] for GART\n",
342 aper_base, aper_base + aper_size - 1);
343 e820__range_add(aper_base, aper_size, E820_TYPE_RESERVED);
344 e820__update_table_print();
345 }
346 }
347
348 if (valid_agp)
349 return;
350
351 /* disable them all at first */
352 for (i = 0; i < amd_nb_bus_dev_ranges[i].dev_limit; i++) {
353 int bus;
354 int dev_base, dev_limit;
355
356 bus = amd_nb_bus_dev_ranges[i].bus;
357 dev_base = amd_nb_bus_dev_ranges[i].dev_base;
358 dev_limit = amd_nb_bus_dev_ranges[i].dev_limit;
359
360 for (slot = dev_base; slot < dev_limit; slot++) {
361 if (!early_is_amd_nb(read_pci_config(bus, slot, 3, 0x00)))
362 continue;
363
364 ctl = read_pci_config(bus, slot, 3, AMD64_GARTAPERTURECTL);
365 ctl &= ~GARTEN;
366 write_pci_config(bus, slot, 3, AMD64_GARTAPERTURECTL, ctl);
367 }
368 }
369
370}
371
372static int __initdata printed_gart_size_msg;
373
374int __init gart_iommu_hole_init(void)
375{
376 u32 agp_aper_base = 0, agp_aper_order = 0;
377 u32 aper_size, aper_alloc = 0, aper_order = 0, last_aper_order = 0;
378 u64 aper_base, last_aper_base = 0;
379 int fix, slot, valid_agp = 0;
380 int i, node;
381
382 if (!amd_gart_present())
383 return -ENODEV;
384
385 if (gart_iommu_aperture_disabled || !fix_aperture ||
386 !early_pci_allowed())
387 return -ENODEV;
388
389 pr_info("Checking aperture...\n");
390
391 if (!fallback_aper_force)
392 agp_aper_base = search_agp_bridge(&agp_aper_order, &valid_agp);
393
394 fix = 0;
395 node = 0;
396 for (i = 0; i < amd_nb_bus_dev_ranges[i].dev_limit; i++) {
397 int bus;
398 int dev_base, dev_limit;
399 u32 ctl;
400
401 bus = amd_nb_bus_dev_ranges[i].bus;
402 dev_base = amd_nb_bus_dev_ranges[i].dev_base;
403 dev_limit = amd_nb_bus_dev_ranges[i].dev_limit;
404
405 for (slot = dev_base; slot < dev_limit; slot++) {
406 if (!early_is_amd_nb(read_pci_config(bus, slot, 3, 0x00)))
407 continue;
408
409 iommu_detected = 1;
410 gart_iommu_aperture = 1;
411 x86_init.iommu.iommu_init = gart_iommu_init;
412
413 ctl = read_pci_config(bus, slot, 3,
414 AMD64_GARTAPERTURECTL);
415
416 /*
417 * Before we do anything else disable the GART. It may
418 * still be enabled if we boot into a crash-kernel here.
419 * Reconfiguring the GART while it is enabled could have
420 * unknown side-effects.
421 */
422 ctl &= ~GARTEN;
423 write_pci_config(bus, slot, 3, AMD64_GARTAPERTURECTL, ctl);
424
425 aper_order = (ctl >> 1) & 7;
426 aper_size = (32 * 1024 * 1024) << aper_order;
427 aper_base = read_pci_config(bus, slot, 3, AMD64_GARTAPERTUREBASE) & 0x7fff;
428 aper_base <<= 25;
429
430 pr_info("Node %d: aperture [bus addr %#010Lx-%#010Lx] (%uMB)\n",
431 node, aper_base, aper_base + aper_size - 1,
432 aper_size >> 20);
433 node++;
434
435 if (!aperture_valid(aper_base, aper_size, 64<<20)) {
436 if (valid_agp && agp_aper_base &&
437 agp_aper_base == aper_base &&
438 agp_aper_order == aper_order) {
439 /* the same between two setting from NB and agp */
440 if (!no_iommu &&
441 max_pfn > MAX_DMA32_PFN &&
442 !printed_gart_size_msg) {
443 pr_err("you are using iommu with agp, but GART size is less than 64MB\n");
444 pr_err("please increase GART size in your BIOS setup\n");
445 pr_err("if BIOS doesn't have that option, contact your HW vendor!\n");
446 printed_gart_size_msg = 1;
447 }
448 } else {
449 fix = 1;
450 goto out;
451 }
452 }
453
454 if ((last_aper_order && aper_order != last_aper_order) ||
455 (last_aper_base && aper_base != last_aper_base)) {
456 fix = 1;
457 goto out;
458 }
459 last_aper_order = aper_order;
460 last_aper_base = aper_base;
461 }
462 }
463
464out:
465 if (!fix && !fallback_aper_force) {
466 if (last_aper_base) {
467 /*
468 * If this is the kdump kernel, the first kernel
469 * may have allocated the range over its e820 RAM
470 * and fixed up the northbridge
471 */
472 exclude_from_vmcore(last_aper_base, last_aper_order);
473
474 return 1;
475 }
476 return 0;
477 }
478
479 if (!fallback_aper_force) {
480 aper_alloc = agp_aper_base;
481 aper_order = agp_aper_order;
482 }
483
484 if (aper_alloc) {
485 /* Got the aperture from the AGP bridge */
486 } else if ((!no_iommu && max_pfn > MAX_DMA32_PFN) ||
487 force_iommu ||
488 valid_agp ||
489 fallback_aper_force) {
490 pr_info("Your BIOS doesn't leave an aperture memory hole\n");
491 pr_info("Please enable the IOMMU option in the BIOS setup\n");
492 pr_info("This costs you %dMB of RAM\n",
493 32 << fallback_aper_order);
494
495 aper_order = fallback_aper_order;
496 aper_alloc = allocate_aperture();
497 if (!aper_alloc) {
498 /*
499 * Could disable AGP and IOMMU here, but it's
500 * probably not worth it. But the later users
501 * cannot deal with bad apertures and turning
502 * on the aperture over memory causes very
503 * strange problems, so it's better to panic
504 * early.
505 */
506 panic("Not enough memory for aperture");
507 }
508 } else {
509 return 0;
510 }
511
512 /*
513 * If this is the kdump kernel _and_ the first kernel did not
514 * configure the aperture in the northbridge, this range may
515 * overlap with the first kernel's memory. We can't access the
516 * range through vmcore even though it should be part of the dump.
517 */
518 exclude_from_vmcore(aper_alloc, aper_order);
519
520 /* Fix up the north bridges */
521 for (i = 0; i < amd_nb_bus_dev_ranges[i].dev_limit; i++) {
522 int bus, dev_base, dev_limit;
523
524 /*
525 * Don't enable translation yet but enable GART IO and CPU
526 * accesses and set DISTLBWALKPRB since GART table memory is UC.
527 */
528 u32 ctl = aper_order << 1;
529
530 bus = amd_nb_bus_dev_ranges[i].bus;
531 dev_base = amd_nb_bus_dev_ranges[i].dev_base;
532 dev_limit = amd_nb_bus_dev_ranges[i].dev_limit;
533 for (slot = dev_base; slot < dev_limit; slot++) {
534 if (!early_is_amd_nb(read_pci_config(bus, slot, 3, 0x00)))
535 continue;
536
537 write_pci_config(bus, slot, 3, AMD64_GARTAPERTURECTL, ctl);
538 write_pci_config(bus, slot, 3, AMD64_GARTAPERTUREBASE, aper_alloc >> 25);
539 }
540 }
541
542 set_up_gart_resume(aper_order, aper_alloc);
543
544 return 1;
545}
1/*
2 * Firmware replacement code.
3 *
4 * Work around broken BIOSes that don't set an aperture, only set the
5 * aperture in the AGP bridge, or set too small aperture.
6 *
7 * If all fails map the aperture over some low memory. This is cheaper than
8 * doing bounce buffering. The memory is lost. This is done at early boot
9 * because only the bootmem allocator can allocate 32+MB.
10 *
11 * Copyright 2002 Andi Kleen, SuSE Labs.
12 */
13#include <linux/kernel.h>
14#include <linux/types.h>
15#include <linux/init.h>
16#include <linux/memblock.h>
17#include <linux/mmzone.h>
18#include <linux/pci_ids.h>
19#include <linux/pci.h>
20#include <linux/bitops.h>
21#include <linux/ioport.h>
22#include <linux/suspend.h>
23#include <asm/e820.h>
24#include <asm/io.h>
25#include <asm/iommu.h>
26#include <asm/gart.h>
27#include <asm/pci-direct.h>
28#include <asm/dma.h>
29#include <asm/amd_nb.h>
30#include <asm/x86_init.h>
31
32/*
33 * Using 512M as goal, in case kexec will load kernel_big
34 * that will do the on-position decompress, and could overlap with
35 * with the gart aperture that is used.
36 * Sequence:
37 * kernel_small
38 * ==> kexec (with kdump trigger path or gart still enabled)
39 * ==> kernel_small (gart area become e820_reserved)
40 * ==> kexec (with kdump trigger path or gart still enabled)
41 * ==> kerne_big (uncompressed size will be big than 64M or 128M)
42 * So don't use 512M below as gart iommu, leave the space for kernel
43 * code for safe.
44 */
45#define GART_MIN_ADDR (512ULL << 20)
46#define GART_MAX_ADDR (1ULL << 32)
47
48int gart_iommu_aperture;
49int gart_iommu_aperture_disabled __initdata;
50int gart_iommu_aperture_allowed __initdata;
51
52int fallback_aper_order __initdata = 1; /* 64MB */
53int fallback_aper_force __initdata;
54
55int fix_aperture __initdata = 1;
56
57static struct resource gart_resource = {
58 .name = "GART",
59 .flags = IORESOURCE_MEM,
60};
61
62static void __init insert_aperture_resource(u32 aper_base, u32 aper_size)
63{
64 gart_resource.start = aper_base;
65 gart_resource.end = aper_base + aper_size - 1;
66 insert_resource(&iomem_resource, &gart_resource);
67}
68
69/* This code runs before the PCI subsystem is initialized, so just
70 access the northbridge directly. */
71
72static u32 __init allocate_aperture(void)
73{
74 u32 aper_size;
75 unsigned long addr;
76
77 /* aper_size should <= 1G */
78 if (fallback_aper_order > 5)
79 fallback_aper_order = 5;
80 aper_size = (32 * 1024 * 1024) << fallback_aper_order;
81
82 /*
83 * Aperture has to be naturally aligned. This means a 2GB aperture
84 * won't have much chance of finding a place in the lower 4GB of
85 * memory. Unfortunately we cannot move it up because that would
86 * make the IOMMU useless.
87 */
88 addr = memblock_find_in_range(GART_MIN_ADDR, GART_MAX_ADDR,
89 aper_size, aper_size);
90 if (!addr || addr + aper_size > GART_MAX_ADDR) {
91 printk(KERN_ERR
92 "Cannot allocate aperture memory hole (%lx,%uK)\n",
93 addr, aper_size>>10);
94 return 0;
95 }
96 memblock_reserve(addr, aper_size);
97 printk(KERN_INFO "Mapping aperture over %d KB of RAM @ %lx\n",
98 aper_size >> 10, addr);
99 insert_aperture_resource((u32)addr, aper_size);
100 register_nosave_region(addr >> PAGE_SHIFT,
101 (addr+aper_size) >> PAGE_SHIFT);
102
103 return (u32)addr;
104}
105
106
107/* Find a PCI capability */
108static u32 __init find_cap(int bus, int slot, int func, int cap)
109{
110 int bytes;
111 u8 pos;
112
113 if (!(read_pci_config_16(bus, slot, func, PCI_STATUS) &
114 PCI_STATUS_CAP_LIST))
115 return 0;
116
117 pos = read_pci_config_byte(bus, slot, func, PCI_CAPABILITY_LIST);
118 for (bytes = 0; bytes < 48 && pos >= 0x40; bytes++) {
119 u8 id;
120
121 pos &= ~3;
122 id = read_pci_config_byte(bus, slot, func, pos+PCI_CAP_LIST_ID);
123 if (id == 0xff)
124 break;
125 if (id == cap)
126 return pos;
127 pos = read_pci_config_byte(bus, slot, func,
128 pos+PCI_CAP_LIST_NEXT);
129 }
130 return 0;
131}
132
133/* Read a standard AGPv3 bridge header */
134static u32 __init read_agp(int bus, int slot, int func, int cap, u32 *order)
135{
136 u32 apsize;
137 u32 apsizereg;
138 int nbits;
139 u32 aper_low, aper_hi;
140 u64 aper;
141 u32 old_order;
142
143 printk(KERN_INFO "AGP bridge at %02x:%02x:%02x\n", bus, slot, func);
144 apsizereg = read_pci_config_16(bus, slot, func, cap + 0x14);
145 if (apsizereg == 0xffffffff) {
146 printk(KERN_ERR "APSIZE in AGP bridge unreadable\n");
147 return 0;
148 }
149
150 /* old_order could be the value from NB gart setting */
151 old_order = *order;
152
153 apsize = apsizereg & 0xfff;
154 /* Some BIOS use weird encodings not in the AGPv3 table. */
155 if (apsize & 0xff)
156 apsize |= 0xf00;
157 nbits = hweight16(apsize);
158 *order = 7 - nbits;
159 if ((int)*order < 0) /* < 32MB */
160 *order = 0;
161
162 aper_low = read_pci_config(bus, slot, func, 0x10);
163 aper_hi = read_pci_config(bus, slot, func, 0x14);
164 aper = (aper_low & ~((1<<22)-1)) | ((u64)aper_hi << 32);
165
166 /*
167 * On some sick chips, APSIZE is 0. It means it wants 4G
168 * so let double check that order, and lets trust AMD NB settings:
169 */
170 printk(KERN_INFO "Aperture from AGP @ %Lx old size %u MB\n",
171 aper, 32 << old_order);
172 if (aper + (32ULL<<(20 + *order)) > 0x100000000ULL) {
173 printk(KERN_INFO "Aperture size %u MB (APSIZE %x) is not right, using settings from NB\n",
174 32 << *order, apsizereg);
175 *order = old_order;
176 }
177
178 printk(KERN_INFO "Aperture from AGP @ %Lx size %u MB (APSIZE %x)\n",
179 aper, 32 << *order, apsizereg);
180
181 if (!aperture_valid(aper, (32*1024*1024) << *order, 32<<20))
182 return 0;
183 return (u32)aper;
184}
185
186/*
187 * Look for an AGP bridge. Windows only expects the aperture in the
188 * AGP bridge and some BIOS forget to initialize the Northbridge too.
189 * Work around this here.
190 *
191 * Do an PCI bus scan by hand because we're running before the PCI
192 * subsystem.
193 *
194 * All AMD AGP bridges are AGPv3 compliant, so we can do this scan
195 * generically. It's probably overkill to always scan all slots because
196 * the AGP bridges should be always an own bus on the HT hierarchy,
197 * but do it here for future safety.
198 */
199static u32 __init search_agp_bridge(u32 *order, int *valid_agp)
200{
201 int bus, slot, func;
202
203 /* Poor man's PCI discovery */
204 for (bus = 0; bus < 256; bus++) {
205 for (slot = 0; slot < 32; slot++) {
206 for (func = 0; func < 8; func++) {
207 u32 class, cap;
208 u8 type;
209 class = read_pci_config(bus, slot, func,
210 PCI_CLASS_REVISION);
211 if (class == 0xffffffff)
212 break;
213
214 switch (class >> 16) {
215 case PCI_CLASS_BRIDGE_HOST:
216 case PCI_CLASS_BRIDGE_OTHER: /* needed? */
217 /* AGP bridge? */
218 cap = find_cap(bus, slot, func,
219 PCI_CAP_ID_AGP);
220 if (!cap)
221 break;
222 *valid_agp = 1;
223 return read_agp(bus, slot, func, cap,
224 order);
225 }
226
227 /* No multi-function device? */
228 type = read_pci_config_byte(bus, slot, func,
229 PCI_HEADER_TYPE);
230 if (!(type & 0x80))
231 break;
232 }
233 }
234 }
235 printk(KERN_INFO "No AGP bridge found\n");
236
237 return 0;
238}
239
240static int gart_fix_e820 __initdata = 1;
241
242static int __init parse_gart_mem(char *p)
243{
244 if (!p)
245 return -EINVAL;
246
247 if (!strncmp(p, "off", 3))
248 gart_fix_e820 = 0;
249 else if (!strncmp(p, "on", 2))
250 gart_fix_e820 = 1;
251
252 return 0;
253}
254early_param("gart_fix_e820", parse_gart_mem);
255
256void __init early_gart_iommu_check(void)
257{
258 /*
259 * in case it is enabled before, esp for kexec/kdump,
260 * previous kernel already enable that. memset called
261 * by allocate_aperture/__alloc_bootmem_nopanic cause restart.
262 * or second kernel have different position for GART hole. and new
263 * kernel could use hole as RAM that is still used by GART set by
264 * first kernel
265 * or BIOS forget to put that in reserved.
266 * try to update e820 to make that region as reserved.
267 */
268 u32 agp_aper_order = 0;
269 int i, fix, slot, valid_agp = 0;
270 u32 ctl;
271 u32 aper_size = 0, aper_order = 0, last_aper_order = 0;
272 u64 aper_base = 0, last_aper_base = 0;
273 int aper_enabled = 0, last_aper_enabled = 0, last_valid = 0;
274
275 if (!early_pci_allowed())
276 return;
277
278 /* This is mostly duplicate of iommu_hole_init */
279 search_agp_bridge(&agp_aper_order, &valid_agp);
280
281 fix = 0;
282 for (i = 0; amd_nb_bus_dev_ranges[i].dev_limit; i++) {
283 int bus;
284 int dev_base, dev_limit;
285
286 bus = amd_nb_bus_dev_ranges[i].bus;
287 dev_base = amd_nb_bus_dev_ranges[i].dev_base;
288 dev_limit = amd_nb_bus_dev_ranges[i].dev_limit;
289
290 for (slot = dev_base; slot < dev_limit; slot++) {
291 if (!early_is_amd_nb(read_pci_config(bus, slot, 3, 0x00)))
292 continue;
293
294 ctl = read_pci_config(bus, slot, 3, AMD64_GARTAPERTURECTL);
295 aper_enabled = ctl & GARTEN;
296 aper_order = (ctl >> 1) & 7;
297 aper_size = (32 * 1024 * 1024) << aper_order;
298 aper_base = read_pci_config(bus, slot, 3, AMD64_GARTAPERTUREBASE) & 0x7fff;
299 aper_base <<= 25;
300
301 if (last_valid) {
302 if ((aper_order != last_aper_order) ||
303 (aper_base != last_aper_base) ||
304 (aper_enabled != last_aper_enabled)) {
305 fix = 1;
306 break;
307 }
308 }
309
310 last_aper_order = aper_order;
311 last_aper_base = aper_base;
312 last_aper_enabled = aper_enabled;
313 last_valid = 1;
314 }
315 }
316
317 if (!fix && !aper_enabled)
318 return;
319
320 if (!aper_base || !aper_size || aper_base + aper_size > 0x100000000UL)
321 fix = 1;
322
323 if (gart_fix_e820 && !fix && aper_enabled) {
324 if (e820_any_mapped(aper_base, aper_base + aper_size,
325 E820_RAM)) {
326 /* reserve it, so we can reuse it in second kernel */
327 printk(KERN_INFO "update e820 for GART\n");
328 e820_add_region(aper_base, aper_size, E820_RESERVED);
329 update_e820();
330 }
331 }
332
333 if (valid_agp)
334 return;
335
336 /* disable them all at first */
337 for (i = 0; i < amd_nb_bus_dev_ranges[i].dev_limit; i++) {
338 int bus;
339 int dev_base, dev_limit;
340
341 bus = amd_nb_bus_dev_ranges[i].bus;
342 dev_base = amd_nb_bus_dev_ranges[i].dev_base;
343 dev_limit = amd_nb_bus_dev_ranges[i].dev_limit;
344
345 for (slot = dev_base; slot < dev_limit; slot++) {
346 if (!early_is_amd_nb(read_pci_config(bus, slot, 3, 0x00)))
347 continue;
348
349 ctl = read_pci_config(bus, slot, 3, AMD64_GARTAPERTURECTL);
350 ctl &= ~GARTEN;
351 write_pci_config(bus, slot, 3, AMD64_GARTAPERTURECTL, ctl);
352 }
353 }
354
355}
356
357static int __initdata printed_gart_size_msg;
358
359int __init gart_iommu_hole_init(void)
360{
361 u32 agp_aper_base = 0, agp_aper_order = 0;
362 u32 aper_size, aper_alloc = 0, aper_order = 0, last_aper_order = 0;
363 u64 aper_base, last_aper_base = 0;
364 int fix, slot, valid_agp = 0;
365 int i, node;
366
367 if (gart_iommu_aperture_disabled || !fix_aperture ||
368 !early_pci_allowed())
369 return -ENODEV;
370
371 printk(KERN_INFO "Checking aperture...\n");
372
373 if (!fallback_aper_force)
374 agp_aper_base = search_agp_bridge(&agp_aper_order, &valid_agp);
375
376 fix = 0;
377 node = 0;
378 for (i = 0; i < amd_nb_bus_dev_ranges[i].dev_limit; i++) {
379 int bus;
380 int dev_base, dev_limit;
381 u32 ctl;
382
383 bus = amd_nb_bus_dev_ranges[i].bus;
384 dev_base = amd_nb_bus_dev_ranges[i].dev_base;
385 dev_limit = amd_nb_bus_dev_ranges[i].dev_limit;
386
387 for (slot = dev_base; slot < dev_limit; slot++) {
388 if (!early_is_amd_nb(read_pci_config(bus, slot, 3, 0x00)))
389 continue;
390
391 iommu_detected = 1;
392 gart_iommu_aperture = 1;
393 x86_init.iommu.iommu_init = gart_iommu_init;
394
395 ctl = read_pci_config(bus, slot, 3,
396 AMD64_GARTAPERTURECTL);
397
398 /*
399 * Before we do anything else disable the GART. It may
400 * still be enabled if we boot into a crash-kernel here.
401 * Reconfiguring the GART while it is enabled could have
402 * unknown side-effects.
403 */
404 ctl &= ~GARTEN;
405 write_pci_config(bus, slot, 3, AMD64_GARTAPERTURECTL, ctl);
406
407 aper_order = (ctl >> 1) & 7;
408 aper_size = (32 * 1024 * 1024) << aper_order;
409 aper_base = read_pci_config(bus, slot, 3, AMD64_GARTAPERTUREBASE) & 0x7fff;
410 aper_base <<= 25;
411
412 printk(KERN_INFO "Node %d: aperture @ %Lx size %u MB\n",
413 node, aper_base, aper_size >> 20);
414 node++;
415
416 if (!aperture_valid(aper_base, aper_size, 64<<20)) {
417 if (valid_agp && agp_aper_base &&
418 agp_aper_base == aper_base &&
419 agp_aper_order == aper_order) {
420 /* the same between two setting from NB and agp */
421 if (!no_iommu &&
422 max_pfn > MAX_DMA32_PFN &&
423 !printed_gart_size_msg) {
424 printk(KERN_ERR "you are using iommu with agp, but GART size is less than 64M\n");
425 printk(KERN_ERR "please increase GART size in your BIOS setup\n");
426 printk(KERN_ERR "if BIOS doesn't have that option, contact your HW vendor!\n");
427 printed_gart_size_msg = 1;
428 }
429 } else {
430 fix = 1;
431 goto out;
432 }
433 }
434
435 if ((last_aper_order && aper_order != last_aper_order) ||
436 (last_aper_base && aper_base != last_aper_base)) {
437 fix = 1;
438 goto out;
439 }
440 last_aper_order = aper_order;
441 last_aper_base = aper_base;
442 }
443 }
444
445out:
446 if (!fix && !fallback_aper_force) {
447 if (last_aper_base) {
448 unsigned long n = (32 * 1024 * 1024) << last_aper_order;
449
450 insert_aperture_resource((u32)last_aper_base, n);
451 return 1;
452 }
453 return 0;
454 }
455
456 if (!fallback_aper_force) {
457 aper_alloc = agp_aper_base;
458 aper_order = agp_aper_order;
459 }
460
461 if (aper_alloc) {
462 /* Got the aperture from the AGP bridge */
463 } else if ((!no_iommu && max_pfn > MAX_DMA32_PFN) ||
464 force_iommu ||
465 valid_agp ||
466 fallback_aper_force) {
467 printk(KERN_INFO
468 "Your BIOS doesn't leave a aperture memory hole\n");
469 printk(KERN_INFO
470 "Please enable the IOMMU option in the BIOS setup\n");
471 printk(KERN_INFO
472 "This costs you %d MB of RAM\n",
473 32 << fallback_aper_order);
474
475 aper_order = fallback_aper_order;
476 aper_alloc = allocate_aperture();
477 if (!aper_alloc) {
478 /*
479 * Could disable AGP and IOMMU here, but it's
480 * probably not worth it. But the later users
481 * cannot deal with bad apertures and turning
482 * on the aperture over memory causes very
483 * strange problems, so it's better to panic
484 * early.
485 */
486 panic("Not enough memory for aperture");
487 }
488 } else {
489 return 0;
490 }
491
492 /* Fix up the north bridges */
493 for (i = 0; i < amd_nb_bus_dev_ranges[i].dev_limit; i++) {
494 int bus, dev_base, dev_limit;
495
496 /*
497 * Don't enable translation yet but enable GART IO and CPU
498 * accesses and set DISTLBWALKPRB since GART table memory is UC.
499 */
500 u32 ctl = aper_order << 1;
501
502 bus = amd_nb_bus_dev_ranges[i].bus;
503 dev_base = amd_nb_bus_dev_ranges[i].dev_base;
504 dev_limit = amd_nb_bus_dev_ranges[i].dev_limit;
505 for (slot = dev_base; slot < dev_limit; slot++) {
506 if (!early_is_amd_nb(read_pci_config(bus, slot, 3, 0x00)))
507 continue;
508
509 write_pci_config(bus, slot, 3, AMD64_GARTAPERTURECTL, ctl);
510 write_pci_config(bus, slot, 3, AMD64_GARTAPERTUREBASE, aper_alloc >> 25);
511 }
512 }
513
514 set_up_gart_resume(aper_order, aper_alloc);
515
516 return 1;
517}