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1/*
2 * Dynamic DMA mapping support for AMD Hammer.
3 *
4 * Use the integrated AGP GART in the Hammer northbridge as an IOMMU for PCI.
5 * This allows to use PCI devices that only support 32bit addresses on systems
6 * with more than 4GB.
7 *
8 * See Documentation/DMA-API-HOWTO.txt for the interface specification.
9 *
10 * Copyright 2002 Andi Kleen, SuSE Labs.
11 * Subject to the GNU General Public License v2 only.
12 */
13
14#include <linux/types.h>
15#include <linux/ctype.h>
16#include <linux/agp_backend.h>
17#include <linux/init.h>
18#include <linux/mm.h>
19#include <linux/sched.h>
20#include <linux/sched/debug.h>
21#include <linux/string.h>
22#include <linux/spinlock.h>
23#include <linux/pci.h>
24#include <linux/topology.h>
25#include <linux/interrupt.h>
26#include <linux/bitmap.h>
27#include <linux/kdebug.h>
28#include <linux/scatterlist.h>
29#include <linux/iommu-helper.h>
30#include <linux/syscore_ops.h>
31#include <linux/io.h>
32#include <linux/gfp.h>
33#include <linux/atomic.h>
34#include <linux/dma-direct.h>
35#include <asm/mtrr.h>
36#include <asm/pgtable.h>
37#include <asm/proto.h>
38#include <asm/iommu.h>
39#include <asm/gart.h>
40#include <asm/set_memory.h>
41#include <asm/swiotlb.h>
42#include <asm/dma.h>
43#include <asm/amd_nb.h>
44#include <asm/x86_init.h>
45#include <asm/iommu_table.h>
46
47static unsigned long iommu_bus_base; /* GART remapping area (physical) */
48static unsigned long iommu_size; /* size of remapping area bytes */
49static unsigned long iommu_pages; /* .. and in pages */
50
51static u32 *iommu_gatt_base; /* Remapping table */
52
53static dma_addr_t bad_dma_addr;
54
55/*
56 * If this is disabled the IOMMU will use an optimized flushing strategy
57 * of only flushing when an mapping is reused. With it true the GART is
58 * flushed for every mapping. Problem is that doing the lazy flush seems
59 * to trigger bugs with some popular PCI cards, in particular 3ware (but
60 * has been also also seen with Qlogic at least).
61 */
62static int iommu_fullflush = 1;
63
64/* Allocation bitmap for the remapping area: */
65static DEFINE_SPINLOCK(iommu_bitmap_lock);
66/* Guarded by iommu_bitmap_lock: */
67static unsigned long *iommu_gart_bitmap;
68
69static u32 gart_unmapped_entry;
70
71#define GPTE_VALID 1
72#define GPTE_COHERENT 2
73#define GPTE_ENCODE(x) \
74 (((x) & 0xfffff000) | (((x) >> 32) << 4) | GPTE_VALID | GPTE_COHERENT)
75#define GPTE_DECODE(x) (((x) & 0xfffff000) | (((u64)(x) & 0xff0) << 28))
76
77#define EMERGENCY_PAGES 32 /* = 128KB */
78
79#ifdef CONFIG_AGP
80#define AGPEXTERN extern
81#else
82#define AGPEXTERN
83#endif
84
85/* GART can only remap to physical addresses < 1TB */
86#define GART_MAX_PHYS_ADDR (1ULL << 40)
87
88/* backdoor interface to AGP driver */
89AGPEXTERN int agp_memory_reserved;
90AGPEXTERN __u32 *agp_gatt_table;
91
92static unsigned long next_bit; /* protected by iommu_bitmap_lock */
93static bool need_flush; /* global flush state. set for each gart wrap */
94
95static unsigned long alloc_iommu(struct device *dev, int size,
96 unsigned long align_mask)
97{
98 unsigned long offset, flags;
99 unsigned long boundary_size;
100 unsigned long base_index;
101
102 base_index = ALIGN(iommu_bus_base & dma_get_seg_boundary(dev),
103 PAGE_SIZE) >> PAGE_SHIFT;
104 boundary_size = ALIGN((u64)dma_get_seg_boundary(dev) + 1,
105 PAGE_SIZE) >> PAGE_SHIFT;
106
107 spin_lock_irqsave(&iommu_bitmap_lock, flags);
108 offset = iommu_area_alloc(iommu_gart_bitmap, iommu_pages, next_bit,
109 size, base_index, boundary_size, align_mask);
110 if (offset == -1) {
111 need_flush = true;
112 offset = iommu_area_alloc(iommu_gart_bitmap, iommu_pages, 0,
113 size, base_index, boundary_size,
114 align_mask);
115 }
116 if (offset != -1) {
117 next_bit = offset+size;
118 if (next_bit >= iommu_pages) {
119 next_bit = 0;
120 need_flush = true;
121 }
122 }
123 if (iommu_fullflush)
124 need_flush = true;
125 spin_unlock_irqrestore(&iommu_bitmap_lock, flags);
126
127 return offset;
128}
129
130static void free_iommu(unsigned long offset, int size)
131{
132 unsigned long flags;
133
134 spin_lock_irqsave(&iommu_bitmap_lock, flags);
135 bitmap_clear(iommu_gart_bitmap, offset, size);
136 if (offset >= next_bit)
137 next_bit = offset + size;
138 spin_unlock_irqrestore(&iommu_bitmap_lock, flags);
139}
140
141/*
142 * Use global flush state to avoid races with multiple flushers.
143 */
144static void flush_gart(void)
145{
146 unsigned long flags;
147
148 spin_lock_irqsave(&iommu_bitmap_lock, flags);
149 if (need_flush) {
150 amd_flush_garts();
151 need_flush = false;
152 }
153 spin_unlock_irqrestore(&iommu_bitmap_lock, flags);
154}
155
156#ifdef CONFIG_IOMMU_LEAK
157/* Debugging aid for drivers that don't free their IOMMU tables */
158static int leak_trace;
159static int iommu_leak_pages = 20;
160
161static void dump_leak(void)
162{
163 static int dump;
164
165 if (dump)
166 return;
167 dump = 1;
168
169 show_stack(NULL, NULL);
170 debug_dma_dump_mappings(NULL);
171}
172#endif
173
174static void iommu_full(struct device *dev, size_t size, int dir)
175{
176 /*
177 * Ran out of IOMMU space for this operation. This is very bad.
178 * Unfortunately the drivers cannot handle this operation properly.
179 * Return some non mapped prereserved space in the aperture and
180 * let the Northbridge deal with it. This will result in garbage
181 * in the IO operation. When the size exceeds the prereserved space
182 * memory corruption will occur or random memory will be DMAed
183 * out. Hopefully no network devices use single mappings that big.
184 */
185
186 dev_err(dev, "PCI-DMA: Out of IOMMU space for %lu bytes\n", size);
187
188 if (size > PAGE_SIZE*EMERGENCY_PAGES) {
189 if (dir == PCI_DMA_FROMDEVICE || dir == PCI_DMA_BIDIRECTIONAL)
190 panic("PCI-DMA: Memory would be corrupted\n");
191 if (dir == PCI_DMA_TODEVICE || dir == PCI_DMA_BIDIRECTIONAL)
192 panic(KERN_ERR
193 "PCI-DMA: Random memory would be DMAed\n");
194 }
195#ifdef CONFIG_IOMMU_LEAK
196 dump_leak();
197#endif
198}
199
200static inline int
201need_iommu(struct device *dev, unsigned long addr, size_t size)
202{
203 return force_iommu || !dma_capable(dev, addr, size);
204}
205
206static inline int
207nonforced_iommu(struct device *dev, unsigned long addr, size_t size)
208{
209 return !dma_capable(dev, addr, size);
210}
211
212/* Map a single continuous physical area into the IOMMU.
213 * Caller needs to check if the iommu is needed and flush.
214 */
215static dma_addr_t dma_map_area(struct device *dev, dma_addr_t phys_mem,
216 size_t size, int dir, unsigned long align_mask)
217{
218 unsigned long npages = iommu_num_pages(phys_mem, size, PAGE_SIZE);
219 unsigned long iommu_page;
220 int i;
221
222 if (unlikely(phys_mem + size > GART_MAX_PHYS_ADDR))
223 return bad_dma_addr;
224
225 iommu_page = alloc_iommu(dev, npages, align_mask);
226 if (iommu_page == -1) {
227 if (!nonforced_iommu(dev, phys_mem, size))
228 return phys_mem;
229 if (panic_on_overflow)
230 panic("dma_map_area overflow %lu bytes\n", size);
231 iommu_full(dev, size, dir);
232 return bad_dma_addr;
233 }
234
235 for (i = 0; i < npages; i++) {
236 iommu_gatt_base[iommu_page + i] = GPTE_ENCODE(phys_mem);
237 phys_mem += PAGE_SIZE;
238 }
239 return iommu_bus_base + iommu_page*PAGE_SIZE + (phys_mem & ~PAGE_MASK);
240}
241
242/* Map a single area into the IOMMU */
243static dma_addr_t gart_map_page(struct device *dev, struct page *page,
244 unsigned long offset, size_t size,
245 enum dma_data_direction dir,
246 unsigned long attrs)
247{
248 unsigned long bus;
249 phys_addr_t paddr = page_to_phys(page) + offset;
250
251 if (!dev)
252 dev = &x86_dma_fallback_dev;
253
254 if (!need_iommu(dev, paddr, size))
255 return paddr;
256
257 bus = dma_map_area(dev, paddr, size, dir, 0);
258 flush_gart();
259
260 return bus;
261}
262
263/*
264 * Free a DMA mapping.
265 */
266static void gart_unmap_page(struct device *dev, dma_addr_t dma_addr,
267 size_t size, enum dma_data_direction dir,
268 unsigned long attrs)
269{
270 unsigned long iommu_page;
271 int npages;
272 int i;
273
274 if (dma_addr < iommu_bus_base + EMERGENCY_PAGES*PAGE_SIZE ||
275 dma_addr >= iommu_bus_base + iommu_size)
276 return;
277
278 iommu_page = (dma_addr - iommu_bus_base)>>PAGE_SHIFT;
279 npages = iommu_num_pages(dma_addr, size, PAGE_SIZE);
280 for (i = 0; i < npages; i++) {
281 iommu_gatt_base[iommu_page + i] = gart_unmapped_entry;
282 }
283 free_iommu(iommu_page, npages);
284}
285
286/*
287 * Wrapper for pci_unmap_single working with scatterlists.
288 */
289static void gart_unmap_sg(struct device *dev, struct scatterlist *sg, int nents,
290 enum dma_data_direction dir, unsigned long attrs)
291{
292 struct scatterlist *s;
293 int i;
294
295 for_each_sg(sg, s, nents, i) {
296 if (!s->dma_length || !s->length)
297 break;
298 gart_unmap_page(dev, s->dma_address, s->dma_length, dir, 0);
299 }
300}
301
302/* Fallback for dma_map_sg in case of overflow */
303static int dma_map_sg_nonforce(struct device *dev, struct scatterlist *sg,
304 int nents, int dir)
305{
306 struct scatterlist *s;
307 int i;
308
309#ifdef CONFIG_IOMMU_DEBUG
310 pr_debug("dma_map_sg overflow\n");
311#endif
312
313 for_each_sg(sg, s, nents, i) {
314 unsigned long addr = sg_phys(s);
315
316 if (nonforced_iommu(dev, addr, s->length)) {
317 addr = dma_map_area(dev, addr, s->length, dir, 0);
318 if (addr == bad_dma_addr) {
319 if (i > 0)
320 gart_unmap_sg(dev, sg, i, dir, 0);
321 nents = 0;
322 sg[0].dma_length = 0;
323 break;
324 }
325 }
326 s->dma_address = addr;
327 s->dma_length = s->length;
328 }
329 flush_gart();
330
331 return nents;
332}
333
334/* Map multiple scatterlist entries continuous into the first. */
335static int __dma_map_cont(struct device *dev, struct scatterlist *start,
336 int nelems, struct scatterlist *sout,
337 unsigned long pages)
338{
339 unsigned long iommu_start = alloc_iommu(dev, pages, 0);
340 unsigned long iommu_page = iommu_start;
341 struct scatterlist *s;
342 int i;
343
344 if (iommu_start == -1)
345 return -1;
346
347 for_each_sg(start, s, nelems, i) {
348 unsigned long pages, addr;
349 unsigned long phys_addr = s->dma_address;
350
351 BUG_ON(s != start && s->offset);
352 if (s == start) {
353 sout->dma_address = iommu_bus_base;
354 sout->dma_address += iommu_page*PAGE_SIZE + s->offset;
355 sout->dma_length = s->length;
356 } else {
357 sout->dma_length += s->length;
358 }
359
360 addr = phys_addr;
361 pages = iommu_num_pages(s->offset, s->length, PAGE_SIZE);
362 while (pages--) {
363 iommu_gatt_base[iommu_page] = GPTE_ENCODE(addr);
364 addr += PAGE_SIZE;
365 iommu_page++;
366 }
367 }
368 BUG_ON(iommu_page - iommu_start != pages);
369
370 return 0;
371}
372
373static inline int
374dma_map_cont(struct device *dev, struct scatterlist *start, int nelems,
375 struct scatterlist *sout, unsigned long pages, int need)
376{
377 if (!need) {
378 BUG_ON(nelems != 1);
379 sout->dma_address = start->dma_address;
380 sout->dma_length = start->length;
381 return 0;
382 }
383 return __dma_map_cont(dev, start, nelems, sout, pages);
384}
385
386/*
387 * DMA map all entries in a scatterlist.
388 * Merge chunks that have page aligned sizes into a continuous mapping.
389 */
390static int gart_map_sg(struct device *dev, struct scatterlist *sg, int nents,
391 enum dma_data_direction dir, unsigned long attrs)
392{
393 struct scatterlist *s, *ps, *start_sg, *sgmap;
394 int need = 0, nextneed, i, out, start;
395 unsigned long pages = 0;
396 unsigned int seg_size;
397 unsigned int max_seg_size;
398
399 if (nents == 0)
400 return 0;
401
402 if (!dev)
403 dev = &x86_dma_fallback_dev;
404
405 out = 0;
406 start = 0;
407 start_sg = sg;
408 sgmap = sg;
409 seg_size = 0;
410 max_seg_size = dma_get_max_seg_size(dev);
411 ps = NULL; /* shut up gcc */
412
413 for_each_sg(sg, s, nents, i) {
414 dma_addr_t addr = sg_phys(s);
415
416 s->dma_address = addr;
417 BUG_ON(s->length == 0);
418
419 nextneed = need_iommu(dev, addr, s->length);
420
421 /* Handle the previous not yet processed entries */
422 if (i > start) {
423 /*
424 * Can only merge when the last chunk ends on a
425 * page boundary and the new one doesn't have an
426 * offset.
427 */
428 if (!iommu_merge || !nextneed || !need || s->offset ||
429 (s->length + seg_size > max_seg_size) ||
430 (ps->offset + ps->length) % PAGE_SIZE) {
431 if (dma_map_cont(dev, start_sg, i - start,
432 sgmap, pages, need) < 0)
433 goto error;
434 out++;
435
436 seg_size = 0;
437 sgmap = sg_next(sgmap);
438 pages = 0;
439 start = i;
440 start_sg = s;
441 }
442 }
443
444 seg_size += s->length;
445 need = nextneed;
446 pages += iommu_num_pages(s->offset, s->length, PAGE_SIZE);
447 ps = s;
448 }
449 if (dma_map_cont(dev, start_sg, i - start, sgmap, pages, need) < 0)
450 goto error;
451 out++;
452 flush_gart();
453 if (out < nents) {
454 sgmap = sg_next(sgmap);
455 sgmap->dma_length = 0;
456 }
457 return out;
458
459error:
460 flush_gart();
461 gart_unmap_sg(dev, sg, out, dir, 0);
462
463 /* When it was forced or merged try again in a dumb way */
464 if (force_iommu || iommu_merge) {
465 out = dma_map_sg_nonforce(dev, sg, nents, dir);
466 if (out > 0)
467 return out;
468 }
469 if (panic_on_overflow)
470 panic("dma_map_sg: overflow on %lu pages\n", pages);
471
472 iommu_full(dev, pages << PAGE_SHIFT, dir);
473 for_each_sg(sg, s, nents, i)
474 s->dma_address = bad_dma_addr;
475 return 0;
476}
477
478/* allocate and map a coherent mapping */
479static void *
480gart_alloc_coherent(struct device *dev, size_t size, dma_addr_t *dma_addr,
481 gfp_t flag, unsigned long attrs)
482{
483 void *vaddr;
484
485 vaddr = dma_direct_alloc(dev, size, dma_addr, flag, attrs);
486 if (!vaddr ||
487 !force_iommu || dev->coherent_dma_mask <= DMA_BIT_MASK(24))
488 return vaddr;
489
490 *dma_addr = dma_map_area(dev, virt_to_phys(vaddr), size,
491 DMA_BIDIRECTIONAL, (1UL << get_order(size)) - 1);
492 flush_gart();
493 if (unlikely(*dma_addr == bad_dma_addr))
494 goto out_free;
495 return vaddr;
496out_free:
497 dma_direct_free(dev, size, vaddr, *dma_addr, attrs);
498 return NULL;
499}
500
501/* free a coherent mapping */
502static void
503gart_free_coherent(struct device *dev, size_t size, void *vaddr,
504 dma_addr_t dma_addr, unsigned long attrs)
505{
506 gart_unmap_page(dev, dma_addr, size, DMA_BIDIRECTIONAL, 0);
507 dma_direct_free(dev, size, vaddr, dma_addr, attrs);
508}
509
510static int gart_mapping_error(struct device *dev, dma_addr_t dma_addr)
511{
512 return (dma_addr == bad_dma_addr);
513}
514
515static int no_agp;
516
517static __init unsigned long check_iommu_size(unsigned long aper, u64 aper_size)
518{
519 unsigned long a;
520
521 if (!iommu_size) {
522 iommu_size = aper_size;
523 if (!no_agp)
524 iommu_size /= 2;
525 }
526
527 a = aper + iommu_size;
528 iommu_size -= round_up(a, PMD_PAGE_SIZE) - a;
529
530 if (iommu_size < 64*1024*1024) {
531 pr_warning(
532 "PCI-DMA: Warning: Small IOMMU %luMB."
533 " Consider increasing the AGP aperture in BIOS\n",
534 iommu_size >> 20);
535 }
536
537 return iommu_size;
538}
539
540static __init unsigned read_aperture(struct pci_dev *dev, u32 *size)
541{
542 unsigned aper_size = 0, aper_base_32, aper_order;
543 u64 aper_base;
544
545 pci_read_config_dword(dev, AMD64_GARTAPERTUREBASE, &aper_base_32);
546 pci_read_config_dword(dev, AMD64_GARTAPERTURECTL, &aper_order);
547 aper_order = (aper_order >> 1) & 7;
548
549 aper_base = aper_base_32 & 0x7fff;
550 aper_base <<= 25;
551
552 aper_size = (32 * 1024 * 1024) << aper_order;
553 if (aper_base + aper_size > 0x100000000UL || !aper_size)
554 aper_base = 0;
555
556 *size = aper_size;
557 return aper_base;
558}
559
560static void enable_gart_translations(void)
561{
562 int i;
563
564 if (!amd_nb_has_feature(AMD_NB_GART))
565 return;
566
567 for (i = 0; i < amd_nb_num(); i++) {
568 struct pci_dev *dev = node_to_amd_nb(i)->misc;
569
570 enable_gart_translation(dev, __pa(agp_gatt_table));
571 }
572
573 /* Flush the GART-TLB to remove stale entries */
574 amd_flush_garts();
575}
576
577/*
578 * If fix_up_north_bridges is set, the north bridges have to be fixed up on
579 * resume in the same way as they are handled in gart_iommu_hole_init().
580 */
581static bool fix_up_north_bridges;
582static u32 aperture_order;
583static u32 aperture_alloc;
584
585void set_up_gart_resume(u32 aper_order, u32 aper_alloc)
586{
587 fix_up_north_bridges = true;
588 aperture_order = aper_order;
589 aperture_alloc = aper_alloc;
590}
591
592static void gart_fixup_northbridges(void)
593{
594 int i;
595
596 if (!fix_up_north_bridges)
597 return;
598
599 if (!amd_nb_has_feature(AMD_NB_GART))
600 return;
601
602 pr_info("PCI-DMA: Restoring GART aperture settings\n");
603
604 for (i = 0; i < amd_nb_num(); i++) {
605 struct pci_dev *dev = node_to_amd_nb(i)->misc;
606
607 /*
608 * Don't enable translations just yet. That is the next
609 * step. Restore the pre-suspend aperture settings.
610 */
611 gart_set_size_and_enable(dev, aperture_order);
612 pci_write_config_dword(dev, AMD64_GARTAPERTUREBASE, aperture_alloc >> 25);
613 }
614}
615
616static void gart_resume(void)
617{
618 pr_info("PCI-DMA: Resuming GART IOMMU\n");
619
620 gart_fixup_northbridges();
621
622 enable_gart_translations();
623}
624
625static struct syscore_ops gart_syscore_ops = {
626 .resume = gart_resume,
627
628};
629
630/*
631 * Private Northbridge GATT initialization in case we cannot use the
632 * AGP driver for some reason.
633 */
634static __init int init_amd_gatt(struct agp_kern_info *info)
635{
636 unsigned aper_size, gatt_size, new_aper_size;
637 unsigned aper_base, new_aper_base;
638 struct pci_dev *dev;
639 void *gatt;
640 int i;
641
642 pr_info("PCI-DMA: Disabling AGP.\n");
643
644 aper_size = aper_base = info->aper_size = 0;
645 dev = NULL;
646 for (i = 0; i < amd_nb_num(); i++) {
647 dev = node_to_amd_nb(i)->misc;
648 new_aper_base = read_aperture(dev, &new_aper_size);
649 if (!new_aper_base)
650 goto nommu;
651
652 if (!aper_base) {
653 aper_size = new_aper_size;
654 aper_base = new_aper_base;
655 }
656 if (aper_size != new_aper_size || aper_base != new_aper_base)
657 goto nommu;
658 }
659 if (!aper_base)
660 goto nommu;
661
662 info->aper_base = aper_base;
663 info->aper_size = aper_size >> 20;
664
665 gatt_size = (aper_size >> PAGE_SHIFT) * sizeof(u32);
666 gatt = (void *)__get_free_pages(GFP_KERNEL | __GFP_ZERO,
667 get_order(gatt_size));
668 if (!gatt)
669 panic("Cannot allocate GATT table");
670 if (set_memory_uc((unsigned long)gatt, gatt_size >> PAGE_SHIFT))
671 panic("Could not set GART PTEs to uncacheable pages");
672
673 agp_gatt_table = gatt;
674
675 register_syscore_ops(&gart_syscore_ops);
676
677 flush_gart();
678
679 pr_info("PCI-DMA: aperture base @ %x size %u KB\n",
680 aper_base, aper_size>>10);
681
682 return 0;
683
684 nommu:
685 /* Should not happen anymore */
686 pr_warning("PCI-DMA: More than 4GB of RAM and no IOMMU\n"
687 "falling back to iommu=soft.\n");
688 return -1;
689}
690
691static const struct dma_map_ops gart_dma_ops = {
692 .map_sg = gart_map_sg,
693 .unmap_sg = gart_unmap_sg,
694 .map_page = gart_map_page,
695 .unmap_page = gart_unmap_page,
696 .alloc = gart_alloc_coherent,
697 .free = gart_free_coherent,
698 .mapping_error = gart_mapping_error,
699 .dma_supported = dma_direct_supported,
700};
701
702static void gart_iommu_shutdown(void)
703{
704 struct pci_dev *dev;
705 int i;
706
707 /* don't shutdown it if there is AGP installed */
708 if (!no_agp)
709 return;
710
711 if (!amd_nb_has_feature(AMD_NB_GART))
712 return;
713
714 for (i = 0; i < amd_nb_num(); i++) {
715 u32 ctl;
716
717 dev = node_to_amd_nb(i)->misc;
718 pci_read_config_dword(dev, AMD64_GARTAPERTURECTL, &ctl);
719
720 ctl &= ~GARTEN;
721
722 pci_write_config_dword(dev, AMD64_GARTAPERTURECTL, ctl);
723 }
724}
725
726int __init gart_iommu_init(void)
727{
728 struct agp_kern_info info;
729 unsigned long iommu_start;
730 unsigned long aper_base, aper_size;
731 unsigned long start_pfn, end_pfn;
732 unsigned long scratch;
733 long i;
734
735 if (!amd_nb_has_feature(AMD_NB_GART))
736 return 0;
737
738#ifndef CONFIG_AGP_AMD64
739 no_agp = 1;
740#else
741 /* Makefile puts PCI initialization via subsys_initcall first. */
742 /* Add other AMD AGP bridge drivers here */
743 no_agp = no_agp ||
744 (agp_amd64_init() < 0) ||
745 (agp_copy_info(agp_bridge, &info) < 0);
746#endif
747
748 if (no_iommu ||
749 (!force_iommu && max_pfn <= MAX_DMA32_PFN) ||
750 !gart_iommu_aperture ||
751 (no_agp && init_amd_gatt(&info) < 0)) {
752 if (max_pfn > MAX_DMA32_PFN) {
753 pr_warning("More than 4GB of memory but GART IOMMU not available.\n");
754 pr_warning("falling back to iommu=soft.\n");
755 }
756 return 0;
757 }
758
759 /* need to map that range */
760 aper_size = info.aper_size << 20;
761 aper_base = info.aper_base;
762 end_pfn = (aper_base>>PAGE_SHIFT) + (aper_size>>PAGE_SHIFT);
763
764 start_pfn = PFN_DOWN(aper_base);
765 if (!pfn_range_is_mapped(start_pfn, end_pfn))
766 init_memory_mapping(start_pfn<<PAGE_SHIFT, end_pfn<<PAGE_SHIFT);
767
768 pr_info("PCI-DMA: using GART IOMMU.\n");
769 iommu_size = check_iommu_size(info.aper_base, aper_size);
770 iommu_pages = iommu_size >> PAGE_SHIFT;
771
772 iommu_gart_bitmap = (void *) __get_free_pages(GFP_KERNEL | __GFP_ZERO,
773 get_order(iommu_pages/8));
774 if (!iommu_gart_bitmap)
775 panic("Cannot allocate iommu bitmap\n");
776
777#ifdef CONFIG_IOMMU_LEAK
778 if (leak_trace) {
779 int ret;
780
781 ret = dma_debug_resize_entries(iommu_pages);
782 if (ret)
783 pr_debug("PCI-DMA: Cannot trace all the entries\n");
784 }
785#endif
786
787 /*
788 * Out of IOMMU space handling.
789 * Reserve some invalid pages at the beginning of the GART.
790 */
791 bitmap_set(iommu_gart_bitmap, 0, EMERGENCY_PAGES);
792
793 pr_info("PCI-DMA: Reserving %luMB of IOMMU area in the AGP aperture\n",
794 iommu_size >> 20);
795
796 agp_memory_reserved = iommu_size;
797 iommu_start = aper_size - iommu_size;
798 iommu_bus_base = info.aper_base + iommu_start;
799 bad_dma_addr = iommu_bus_base;
800 iommu_gatt_base = agp_gatt_table + (iommu_start>>PAGE_SHIFT);
801
802 /*
803 * Unmap the IOMMU part of the GART. The alias of the page is
804 * always mapped with cache enabled and there is no full cache
805 * coherency across the GART remapping. The unmapping avoids
806 * automatic prefetches from the CPU allocating cache lines in
807 * there. All CPU accesses are done via the direct mapping to
808 * the backing memory. The GART address is only used by PCI
809 * devices.
810 */
811 set_memory_np((unsigned long)__va(iommu_bus_base),
812 iommu_size >> PAGE_SHIFT);
813 /*
814 * Tricky. The GART table remaps the physical memory range,
815 * so the CPU wont notice potential aliases and if the memory
816 * is remapped to UC later on, we might surprise the PCI devices
817 * with a stray writeout of a cacheline. So play it sure and
818 * do an explicit, full-scale wbinvd() _after_ having marked all
819 * the pages as Not-Present:
820 */
821 wbinvd();
822
823 /*
824 * Now all caches are flushed and we can safely enable
825 * GART hardware. Doing it early leaves the possibility
826 * of stale cache entries that can lead to GART PTE
827 * errors.
828 */
829 enable_gart_translations();
830
831 /*
832 * Try to workaround a bug (thanks to BenH):
833 * Set unmapped entries to a scratch page instead of 0.
834 * Any prefetches that hit unmapped entries won't get an bus abort
835 * then. (P2P bridge may be prefetching on DMA reads).
836 */
837 scratch = get_zeroed_page(GFP_KERNEL);
838 if (!scratch)
839 panic("Cannot allocate iommu scratch page");
840 gart_unmapped_entry = GPTE_ENCODE(__pa(scratch));
841 for (i = EMERGENCY_PAGES; i < iommu_pages; i++)
842 iommu_gatt_base[i] = gart_unmapped_entry;
843
844 flush_gart();
845 dma_ops = &gart_dma_ops;
846 x86_platform.iommu_shutdown = gart_iommu_shutdown;
847 swiotlb = 0;
848
849 return 0;
850}
851
852void __init gart_parse_options(char *p)
853{
854 int arg;
855
856#ifdef CONFIG_IOMMU_LEAK
857 if (!strncmp(p, "leak", 4)) {
858 leak_trace = 1;
859 p += 4;
860 if (*p == '=')
861 ++p;
862 if (isdigit(*p) && get_option(&p, &arg))
863 iommu_leak_pages = arg;
864 }
865#endif
866 if (isdigit(*p) && get_option(&p, &arg))
867 iommu_size = arg;
868 if (!strncmp(p, "fullflush", 9))
869 iommu_fullflush = 1;
870 if (!strncmp(p, "nofullflush", 11))
871 iommu_fullflush = 0;
872 if (!strncmp(p, "noagp", 5))
873 no_agp = 1;
874 if (!strncmp(p, "noaperture", 10))
875 fix_aperture = 0;
876 /* duplicated from pci-dma.c */
877 if (!strncmp(p, "force", 5))
878 gart_iommu_aperture_allowed = 1;
879 if (!strncmp(p, "allowed", 7))
880 gart_iommu_aperture_allowed = 1;
881 if (!strncmp(p, "memaper", 7)) {
882 fallback_aper_force = 1;
883 p += 7;
884 if (*p == '=') {
885 ++p;
886 if (get_option(&p, &arg))
887 fallback_aper_order = arg;
888 }
889 }
890}
891IOMMU_INIT_POST(gart_iommu_hole_init);
1/*
2 * Dynamic DMA mapping support for AMD Hammer.
3 *
4 * Use the integrated AGP GART in the Hammer northbridge as an IOMMU for PCI.
5 * This allows to use PCI devices that only support 32bit addresses on systems
6 * with more than 4GB.
7 *
8 * See Documentation/DMA-API-HOWTO.txt for the interface specification.
9 *
10 * Copyright 2002 Andi Kleen, SuSE Labs.
11 * Subject to the GNU General Public License v2 only.
12 */
13
14#include <linux/types.h>
15#include <linux/ctype.h>
16#include <linux/agp_backend.h>
17#include <linux/init.h>
18#include <linux/mm.h>
19#include <linux/sched.h>
20#include <linux/string.h>
21#include <linux/spinlock.h>
22#include <linux/pci.h>
23#include <linux/topology.h>
24#include <linux/interrupt.h>
25#include <linux/bitmap.h>
26#include <linux/kdebug.h>
27#include <linux/scatterlist.h>
28#include <linux/iommu-helper.h>
29#include <linux/syscore_ops.h>
30#include <linux/io.h>
31#include <linux/gfp.h>
32#include <linux/atomic.h>
33#include <asm/mtrr.h>
34#include <asm/pgtable.h>
35#include <asm/proto.h>
36#include <asm/iommu.h>
37#include <asm/gart.h>
38#include <asm/cacheflush.h>
39#include <asm/swiotlb.h>
40#include <asm/dma.h>
41#include <asm/amd_nb.h>
42#include <asm/x86_init.h>
43#include <asm/iommu_table.h>
44
45static unsigned long iommu_bus_base; /* GART remapping area (physical) */
46static unsigned long iommu_size; /* size of remapping area bytes */
47static unsigned long iommu_pages; /* .. and in pages */
48
49static u32 *iommu_gatt_base; /* Remapping table */
50
51static dma_addr_t bad_dma_addr;
52
53/*
54 * If this is disabled the IOMMU will use an optimized flushing strategy
55 * of only flushing when an mapping is reused. With it true the GART is
56 * flushed for every mapping. Problem is that doing the lazy flush seems
57 * to trigger bugs with some popular PCI cards, in particular 3ware (but
58 * has been also also seen with Qlogic at least).
59 */
60static int iommu_fullflush = 1;
61
62/* Allocation bitmap for the remapping area: */
63static DEFINE_SPINLOCK(iommu_bitmap_lock);
64/* Guarded by iommu_bitmap_lock: */
65static unsigned long *iommu_gart_bitmap;
66
67static u32 gart_unmapped_entry;
68
69#define GPTE_VALID 1
70#define GPTE_COHERENT 2
71#define GPTE_ENCODE(x) \
72 (((x) & 0xfffff000) | (((x) >> 32) << 4) | GPTE_VALID | GPTE_COHERENT)
73#define GPTE_DECODE(x) (((x) & 0xfffff000) | (((u64)(x) & 0xff0) << 28))
74
75#define EMERGENCY_PAGES 32 /* = 128KB */
76
77#ifdef CONFIG_AGP
78#define AGPEXTERN extern
79#else
80#define AGPEXTERN
81#endif
82
83/* GART can only remap to physical addresses < 1TB */
84#define GART_MAX_PHYS_ADDR (1ULL << 40)
85
86/* backdoor interface to AGP driver */
87AGPEXTERN int agp_memory_reserved;
88AGPEXTERN __u32 *agp_gatt_table;
89
90static unsigned long next_bit; /* protected by iommu_bitmap_lock */
91static bool need_flush; /* global flush state. set for each gart wrap */
92
93static unsigned long alloc_iommu(struct device *dev, int size,
94 unsigned long align_mask)
95{
96 unsigned long offset, flags;
97 unsigned long boundary_size;
98 unsigned long base_index;
99
100 base_index = ALIGN(iommu_bus_base & dma_get_seg_boundary(dev),
101 PAGE_SIZE) >> PAGE_SHIFT;
102 boundary_size = ALIGN((u64)dma_get_seg_boundary(dev) + 1,
103 PAGE_SIZE) >> PAGE_SHIFT;
104
105 spin_lock_irqsave(&iommu_bitmap_lock, flags);
106 offset = iommu_area_alloc(iommu_gart_bitmap, iommu_pages, next_bit,
107 size, base_index, boundary_size, align_mask);
108 if (offset == -1) {
109 need_flush = true;
110 offset = iommu_area_alloc(iommu_gart_bitmap, iommu_pages, 0,
111 size, base_index, boundary_size,
112 align_mask);
113 }
114 if (offset != -1) {
115 next_bit = offset+size;
116 if (next_bit >= iommu_pages) {
117 next_bit = 0;
118 need_flush = true;
119 }
120 }
121 if (iommu_fullflush)
122 need_flush = true;
123 spin_unlock_irqrestore(&iommu_bitmap_lock, flags);
124
125 return offset;
126}
127
128static void free_iommu(unsigned long offset, int size)
129{
130 unsigned long flags;
131
132 spin_lock_irqsave(&iommu_bitmap_lock, flags);
133 bitmap_clear(iommu_gart_bitmap, offset, size);
134 if (offset >= next_bit)
135 next_bit = offset + size;
136 spin_unlock_irqrestore(&iommu_bitmap_lock, flags);
137}
138
139/*
140 * Use global flush state to avoid races with multiple flushers.
141 */
142static void flush_gart(void)
143{
144 unsigned long flags;
145
146 spin_lock_irqsave(&iommu_bitmap_lock, flags);
147 if (need_flush) {
148 amd_flush_garts();
149 need_flush = false;
150 }
151 spin_unlock_irqrestore(&iommu_bitmap_lock, flags);
152}
153
154#ifdef CONFIG_IOMMU_LEAK
155/* Debugging aid for drivers that don't free their IOMMU tables */
156static int leak_trace;
157static int iommu_leak_pages = 20;
158
159static void dump_leak(void)
160{
161 static int dump;
162
163 if (dump)
164 return;
165 dump = 1;
166
167 show_stack(NULL, NULL);
168 debug_dma_dump_mappings(NULL);
169}
170#endif
171
172static void iommu_full(struct device *dev, size_t size, int dir)
173{
174 /*
175 * Ran out of IOMMU space for this operation. This is very bad.
176 * Unfortunately the drivers cannot handle this operation properly.
177 * Return some non mapped prereserved space in the aperture and
178 * let the Northbridge deal with it. This will result in garbage
179 * in the IO operation. When the size exceeds the prereserved space
180 * memory corruption will occur or random memory will be DMAed
181 * out. Hopefully no network devices use single mappings that big.
182 */
183
184 dev_err(dev, "PCI-DMA: Out of IOMMU space for %lu bytes\n", size);
185
186 if (size > PAGE_SIZE*EMERGENCY_PAGES) {
187 if (dir == PCI_DMA_FROMDEVICE || dir == PCI_DMA_BIDIRECTIONAL)
188 panic("PCI-DMA: Memory would be corrupted\n");
189 if (dir == PCI_DMA_TODEVICE || dir == PCI_DMA_BIDIRECTIONAL)
190 panic(KERN_ERR
191 "PCI-DMA: Random memory would be DMAed\n");
192 }
193#ifdef CONFIG_IOMMU_LEAK
194 dump_leak();
195#endif
196}
197
198static inline int
199need_iommu(struct device *dev, unsigned long addr, size_t size)
200{
201 return force_iommu || !dma_capable(dev, addr, size);
202}
203
204static inline int
205nonforced_iommu(struct device *dev, unsigned long addr, size_t size)
206{
207 return !dma_capable(dev, addr, size);
208}
209
210/* Map a single continuous physical area into the IOMMU.
211 * Caller needs to check if the iommu is needed and flush.
212 */
213static dma_addr_t dma_map_area(struct device *dev, dma_addr_t phys_mem,
214 size_t size, int dir, unsigned long align_mask)
215{
216 unsigned long npages = iommu_num_pages(phys_mem, size, PAGE_SIZE);
217 unsigned long iommu_page;
218 int i;
219
220 if (unlikely(phys_mem + size > GART_MAX_PHYS_ADDR))
221 return bad_dma_addr;
222
223 iommu_page = alloc_iommu(dev, npages, align_mask);
224 if (iommu_page == -1) {
225 if (!nonforced_iommu(dev, phys_mem, size))
226 return phys_mem;
227 if (panic_on_overflow)
228 panic("dma_map_area overflow %lu bytes\n", size);
229 iommu_full(dev, size, dir);
230 return bad_dma_addr;
231 }
232
233 for (i = 0; i < npages; i++) {
234 iommu_gatt_base[iommu_page + i] = GPTE_ENCODE(phys_mem);
235 phys_mem += PAGE_SIZE;
236 }
237 return iommu_bus_base + iommu_page*PAGE_SIZE + (phys_mem & ~PAGE_MASK);
238}
239
240/* Map a single area into the IOMMU */
241static dma_addr_t gart_map_page(struct device *dev, struct page *page,
242 unsigned long offset, size_t size,
243 enum dma_data_direction dir,
244 unsigned long attrs)
245{
246 unsigned long bus;
247 phys_addr_t paddr = page_to_phys(page) + offset;
248
249 if (!dev)
250 dev = &x86_dma_fallback_dev;
251
252 if (!need_iommu(dev, paddr, size))
253 return paddr;
254
255 bus = dma_map_area(dev, paddr, size, dir, 0);
256 flush_gart();
257
258 return bus;
259}
260
261/*
262 * Free a DMA mapping.
263 */
264static void gart_unmap_page(struct device *dev, dma_addr_t dma_addr,
265 size_t size, enum dma_data_direction dir,
266 unsigned long attrs)
267{
268 unsigned long iommu_page;
269 int npages;
270 int i;
271
272 if (dma_addr < iommu_bus_base + EMERGENCY_PAGES*PAGE_SIZE ||
273 dma_addr >= iommu_bus_base + iommu_size)
274 return;
275
276 iommu_page = (dma_addr - iommu_bus_base)>>PAGE_SHIFT;
277 npages = iommu_num_pages(dma_addr, size, PAGE_SIZE);
278 for (i = 0; i < npages; i++) {
279 iommu_gatt_base[iommu_page + i] = gart_unmapped_entry;
280 }
281 free_iommu(iommu_page, npages);
282}
283
284/*
285 * Wrapper for pci_unmap_single working with scatterlists.
286 */
287static void gart_unmap_sg(struct device *dev, struct scatterlist *sg, int nents,
288 enum dma_data_direction dir, unsigned long attrs)
289{
290 struct scatterlist *s;
291 int i;
292
293 for_each_sg(sg, s, nents, i) {
294 if (!s->dma_length || !s->length)
295 break;
296 gart_unmap_page(dev, s->dma_address, s->dma_length, dir, 0);
297 }
298}
299
300/* Fallback for dma_map_sg in case of overflow */
301static int dma_map_sg_nonforce(struct device *dev, struct scatterlist *sg,
302 int nents, int dir)
303{
304 struct scatterlist *s;
305 int i;
306
307#ifdef CONFIG_IOMMU_DEBUG
308 pr_debug("dma_map_sg overflow\n");
309#endif
310
311 for_each_sg(sg, s, nents, i) {
312 unsigned long addr = sg_phys(s);
313
314 if (nonforced_iommu(dev, addr, s->length)) {
315 addr = dma_map_area(dev, addr, s->length, dir, 0);
316 if (addr == bad_dma_addr) {
317 if (i > 0)
318 gart_unmap_sg(dev, sg, i, dir, 0);
319 nents = 0;
320 sg[0].dma_length = 0;
321 break;
322 }
323 }
324 s->dma_address = addr;
325 s->dma_length = s->length;
326 }
327 flush_gart();
328
329 return nents;
330}
331
332/* Map multiple scatterlist entries continuous into the first. */
333static int __dma_map_cont(struct device *dev, struct scatterlist *start,
334 int nelems, struct scatterlist *sout,
335 unsigned long pages)
336{
337 unsigned long iommu_start = alloc_iommu(dev, pages, 0);
338 unsigned long iommu_page = iommu_start;
339 struct scatterlist *s;
340 int i;
341
342 if (iommu_start == -1)
343 return -1;
344
345 for_each_sg(start, s, nelems, i) {
346 unsigned long pages, addr;
347 unsigned long phys_addr = s->dma_address;
348
349 BUG_ON(s != start && s->offset);
350 if (s == start) {
351 sout->dma_address = iommu_bus_base;
352 sout->dma_address += iommu_page*PAGE_SIZE + s->offset;
353 sout->dma_length = s->length;
354 } else {
355 sout->dma_length += s->length;
356 }
357
358 addr = phys_addr;
359 pages = iommu_num_pages(s->offset, s->length, PAGE_SIZE);
360 while (pages--) {
361 iommu_gatt_base[iommu_page] = GPTE_ENCODE(addr);
362 addr += PAGE_SIZE;
363 iommu_page++;
364 }
365 }
366 BUG_ON(iommu_page - iommu_start != pages);
367
368 return 0;
369}
370
371static inline int
372dma_map_cont(struct device *dev, struct scatterlist *start, int nelems,
373 struct scatterlist *sout, unsigned long pages, int need)
374{
375 if (!need) {
376 BUG_ON(nelems != 1);
377 sout->dma_address = start->dma_address;
378 sout->dma_length = start->length;
379 return 0;
380 }
381 return __dma_map_cont(dev, start, nelems, sout, pages);
382}
383
384/*
385 * DMA map all entries in a scatterlist.
386 * Merge chunks that have page aligned sizes into a continuous mapping.
387 */
388static int gart_map_sg(struct device *dev, struct scatterlist *sg, int nents,
389 enum dma_data_direction dir, unsigned long attrs)
390{
391 struct scatterlist *s, *ps, *start_sg, *sgmap;
392 int need = 0, nextneed, i, out, start;
393 unsigned long pages = 0;
394 unsigned int seg_size;
395 unsigned int max_seg_size;
396
397 if (nents == 0)
398 return 0;
399
400 if (!dev)
401 dev = &x86_dma_fallback_dev;
402
403 out = 0;
404 start = 0;
405 start_sg = sg;
406 sgmap = sg;
407 seg_size = 0;
408 max_seg_size = dma_get_max_seg_size(dev);
409 ps = NULL; /* shut up gcc */
410
411 for_each_sg(sg, s, nents, i) {
412 dma_addr_t addr = sg_phys(s);
413
414 s->dma_address = addr;
415 BUG_ON(s->length == 0);
416
417 nextneed = need_iommu(dev, addr, s->length);
418
419 /* Handle the previous not yet processed entries */
420 if (i > start) {
421 /*
422 * Can only merge when the last chunk ends on a
423 * page boundary and the new one doesn't have an
424 * offset.
425 */
426 if (!iommu_merge || !nextneed || !need || s->offset ||
427 (s->length + seg_size > max_seg_size) ||
428 (ps->offset + ps->length) % PAGE_SIZE) {
429 if (dma_map_cont(dev, start_sg, i - start,
430 sgmap, pages, need) < 0)
431 goto error;
432 out++;
433
434 seg_size = 0;
435 sgmap = sg_next(sgmap);
436 pages = 0;
437 start = i;
438 start_sg = s;
439 }
440 }
441
442 seg_size += s->length;
443 need = nextneed;
444 pages += iommu_num_pages(s->offset, s->length, PAGE_SIZE);
445 ps = s;
446 }
447 if (dma_map_cont(dev, start_sg, i - start, sgmap, pages, need) < 0)
448 goto error;
449 out++;
450 flush_gart();
451 if (out < nents) {
452 sgmap = sg_next(sgmap);
453 sgmap->dma_length = 0;
454 }
455 return out;
456
457error:
458 flush_gart();
459 gart_unmap_sg(dev, sg, out, dir, 0);
460
461 /* When it was forced or merged try again in a dumb way */
462 if (force_iommu || iommu_merge) {
463 out = dma_map_sg_nonforce(dev, sg, nents, dir);
464 if (out > 0)
465 return out;
466 }
467 if (panic_on_overflow)
468 panic("dma_map_sg: overflow on %lu pages\n", pages);
469
470 iommu_full(dev, pages << PAGE_SHIFT, dir);
471 for_each_sg(sg, s, nents, i)
472 s->dma_address = bad_dma_addr;
473 return 0;
474}
475
476/* allocate and map a coherent mapping */
477static void *
478gart_alloc_coherent(struct device *dev, size_t size, dma_addr_t *dma_addr,
479 gfp_t flag, unsigned long attrs)
480{
481 dma_addr_t paddr;
482 unsigned long align_mask;
483 struct page *page;
484
485 if (force_iommu && !(flag & GFP_DMA)) {
486 flag &= ~(__GFP_DMA | __GFP_HIGHMEM | __GFP_DMA32);
487 page = alloc_pages(flag | __GFP_ZERO, get_order(size));
488 if (!page)
489 return NULL;
490
491 align_mask = (1UL << get_order(size)) - 1;
492 paddr = dma_map_area(dev, page_to_phys(page), size,
493 DMA_BIDIRECTIONAL, align_mask);
494
495 flush_gart();
496 if (paddr != bad_dma_addr) {
497 *dma_addr = paddr;
498 return page_address(page);
499 }
500 __free_pages(page, get_order(size));
501 } else
502 return dma_generic_alloc_coherent(dev, size, dma_addr, flag,
503 attrs);
504
505 return NULL;
506}
507
508/* free a coherent mapping */
509static void
510gart_free_coherent(struct device *dev, size_t size, void *vaddr,
511 dma_addr_t dma_addr, unsigned long attrs)
512{
513 gart_unmap_page(dev, dma_addr, size, DMA_BIDIRECTIONAL, 0);
514 dma_generic_free_coherent(dev, size, vaddr, dma_addr, attrs);
515}
516
517static int gart_mapping_error(struct device *dev, dma_addr_t dma_addr)
518{
519 return (dma_addr == bad_dma_addr);
520}
521
522static int no_agp;
523
524static __init unsigned long check_iommu_size(unsigned long aper, u64 aper_size)
525{
526 unsigned long a;
527
528 if (!iommu_size) {
529 iommu_size = aper_size;
530 if (!no_agp)
531 iommu_size /= 2;
532 }
533
534 a = aper + iommu_size;
535 iommu_size -= round_up(a, PMD_PAGE_SIZE) - a;
536
537 if (iommu_size < 64*1024*1024) {
538 pr_warning(
539 "PCI-DMA: Warning: Small IOMMU %luMB."
540 " Consider increasing the AGP aperture in BIOS\n",
541 iommu_size >> 20);
542 }
543
544 return iommu_size;
545}
546
547static __init unsigned read_aperture(struct pci_dev *dev, u32 *size)
548{
549 unsigned aper_size = 0, aper_base_32, aper_order;
550 u64 aper_base;
551
552 pci_read_config_dword(dev, AMD64_GARTAPERTUREBASE, &aper_base_32);
553 pci_read_config_dword(dev, AMD64_GARTAPERTURECTL, &aper_order);
554 aper_order = (aper_order >> 1) & 7;
555
556 aper_base = aper_base_32 & 0x7fff;
557 aper_base <<= 25;
558
559 aper_size = (32 * 1024 * 1024) << aper_order;
560 if (aper_base + aper_size > 0x100000000UL || !aper_size)
561 aper_base = 0;
562
563 *size = aper_size;
564 return aper_base;
565}
566
567static void enable_gart_translations(void)
568{
569 int i;
570
571 if (!amd_nb_has_feature(AMD_NB_GART))
572 return;
573
574 for (i = 0; i < amd_nb_num(); i++) {
575 struct pci_dev *dev = node_to_amd_nb(i)->misc;
576
577 enable_gart_translation(dev, __pa(agp_gatt_table));
578 }
579
580 /* Flush the GART-TLB to remove stale entries */
581 amd_flush_garts();
582}
583
584/*
585 * If fix_up_north_bridges is set, the north bridges have to be fixed up on
586 * resume in the same way as they are handled in gart_iommu_hole_init().
587 */
588static bool fix_up_north_bridges;
589static u32 aperture_order;
590static u32 aperture_alloc;
591
592void set_up_gart_resume(u32 aper_order, u32 aper_alloc)
593{
594 fix_up_north_bridges = true;
595 aperture_order = aper_order;
596 aperture_alloc = aper_alloc;
597}
598
599static void gart_fixup_northbridges(void)
600{
601 int i;
602
603 if (!fix_up_north_bridges)
604 return;
605
606 if (!amd_nb_has_feature(AMD_NB_GART))
607 return;
608
609 pr_info("PCI-DMA: Restoring GART aperture settings\n");
610
611 for (i = 0; i < amd_nb_num(); i++) {
612 struct pci_dev *dev = node_to_amd_nb(i)->misc;
613
614 /*
615 * Don't enable translations just yet. That is the next
616 * step. Restore the pre-suspend aperture settings.
617 */
618 gart_set_size_and_enable(dev, aperture_order);
619 pci_write_config_dword(dev, AMD64_GARTAPERTUREBASE, aperture_alloc >> 25);
620 }
621}
622
623static void gart_resume(void)
624{
625 pr_info("PCI-DMA: Resuming GART IOMMU\n");
626
627 gart_fixup_northbridges();
628
629 enable_gart_translations();
630}
631
632static struct syscore_ops gart_syscore_ops = {
633 .resume = gart_resume,
634
635};
636
637/*
638 * Private Northbridge GATT initialization in case we cannot use the
639 * AGP driver for some reason.
640 */
641static __init int init_amd_gatt(struct agp_kern_info *info)
642{
643 unsigned aper_size, gatt_size, new_aper_size;
644 unsigned aper_base, new_aper_base;
645 struct pci_dev *dev;
646 void *gatt;
647 int i;
648
649 pr_info("PCI-DMA: Disabling AGP.\n");
650
651 aper_size = aper_base = info->aper_size = 0;
652 dev = NULL;
653 for (i = 0; i < amd_nb_num(); i++) {
654 dev = node_to_amd_nb(i)->misc;
655 new_aper_base = read_aperture(dev, &new_aper_size);
656 if (!new_aper_base)
657 goto nommu;
658
659 if (!aper_base) {
660 aper_size = new_aper_size;
661 aper_base = new_aper_base;
662 }
663 if (aper_size != new_aper_size || aper_base != new_aper_base)
664 goto nommu;
665 }
666 if (!aper_base)
667 goto nommu;
668
669 info->aper_base = aper_base;
670 info->aper_size = aper_size >> 20;
671
672 gatt_size = (aper_size >> PAGE_SHIFT) * sizeof(u32);
673 gatt = (void *)__get_free_pages(GFP_KERNEL | __GFP_ZERO,
674 get_order(gatt_size));
675 if (!gatt)
676 panic("Cannot allocate GATT table");
677 if (set_memory_uc((unsigned long)gatt, gatt_size >> PAGE_SHIFT))
678 panic("Could not set GART PTEs to uncacheable pages");
679
680 agp_gatt_table = gatt;
681
682 register_syscore_ops(&gart_syscore_ops);
683
684 flush_gart();
685
686 pr_info("PCI-DMA: aperture base @ %x size %u KB\n",
687 aper_base, aper_size>>10);
688
689 return 0;
690
691 nommu:
692 /* Should not happen anymore */
693 pr_warning("PCI-DMA: More than 4GB of RAM and no IOMMU\n"
694 "falling back to iommu=soft.\n");
695 return -1;
696}
697
698static struct dma_map_ops gart_dma_ops = {
699 .map_sg = gart_map_sg,
700 .unmap_sg = gart_unmap_sg,
701 .map_page = gart_map_page,
702 .unmap_page = gart_unmap_page,
703 .alloc = gart_alloc_coherent,
704 .free = gart_free_coherent,
705 .mapping_error = gart_mapping_error,
706};
707
708static void gart_iommu_shutdown(void)
709{
710 struct pci_dev *dev;
711 int i;
712
713 /* don't shutdown it if there is AGP installed */
714 if (!no_agp)
715 return;
716
717 if (!amd_nb_has_feature(AMD_NB_GART))
718 return;
719
720 for (i = 0; i < amd_nb_num(); i++) {
721 u32 ctl;
722
723 dev = node_to_amd_nb(i)->misc;
724 pci_read_config_dword(dev, AMD64_GARTAPERTURECTL, &ctl);
725
726 ctl &= ~GARTEN;
727
728 pci_write_config_dword(dev, AMD64_GARTAPERTURECTL, ctl);
729 }
730}
731
732int __init gart_iommu_init(void)
733{
734 struct agp_kern_info info;
735 unsigned long iommu_start;
736 unsigned long aper_base, aper_size;
737 unsigned long start_pfn, end_pfn;
738 unsigned long scratch;
739 long i;
740
741 if (!amd_nb_has_feature(AMD_NB_GART))
742 return 0;
743
744#ifndef CONFIG_AGP_AMD64
745 no_agp = 1;
746#else
747 /* Makefile puts PCI initialization via subsys_initcall first. */
748 /* Add other AMD AGP bridge drivers here */
749 no_agp = no_agp ||
750 (agp_amd64_init() < 0) ||
751 (agp_copy_info(agp_bridge, &info) < 0);
752#endif
753
754 if (no_iommu ||
755 (!force_iommu && max_pfn <= MAX_DMA32_PFN) ||
756 !gart_iommu_aperture ||
757 (no_agp && init_amd_gatt(&info) < 0)) {
758 if (max_pfn > MAX_DMA32_PFN) {
759 pr_warning("More than 4GB of memory but GART IOMMU not available.\n");
760 pr_warning("falling back to iommu=soft.\n");
761 }
762 return 0;
763 }
764
765 /* need to map that range */
766 aper_size = info.aper_size << 20;
767 aper_base = info.aper_base;
768 end_pfn = (aper_base>>PAGE_SHIFT) + (aper_size>>PAGE_SHIFT);
769
770 start_pfn = PFN_DOWN(aper_base);
771 if (!pfn_range_is_mapped(start_pfn, end_pfn))
772 init_memory_mapping(start_pfn<<PAGE_SHIFT, end_pfn<<PAGE_SHIFT);
773
774 pr_info("PCI-DMA: using GART IOMMU.\n");
775 iommu_size = check_iommu_size(info.aper_base, aper_size);
776 iommu_pages = iommu_size >> PAGE_SHIFT;
777
778 iommu_gart_bitmap = (void *) __get_free_pages(GFP_KERNEL | __GFP_ZERO,
779 get_order(iommu_pages/8));
780 if (!iommu_gart_bitmap)
781 panic("Cannot allocate iommu bitmap\n");
782
783#ifdef CONFIG_IOMMU_LEAK
784 if (leak_trace) {
785 int ret;
786
787 ret = dma_debug_resize_entries(iommu_pages);
788 if (ret)
789 pr_debug("PCI-DMA: Cannot trace all the entries\n");
790 }
791#endif
792
793 /*
794 * Out of IOMMU space handling.
795 * Reserve some invalid pages at the beginning of the GART.
796 */
797 bitmap_set(iommu_gart_bitmap, 0, EMERGENCY_PAGES);
798
799 pr_info("PCI-DMA: Reserving %luMB of IOMMU area in the AGP aperture\n",
800 iommu_size >> 20);
801
802 agp_memory_reserved = iommu_size;
803 iommu_start = aper_size - iommu_size;
804 iommu_bus_base = info.aper_base + iommu_start;
805 bad_dma_addr = iommu_bus_base;
806 iommu_gatt_base = agp_gatt_table + (iommu_start>>PAGE_SHIFT);
807
808 /*
809 * Unmap the IOMMU part of the GART. The alias of the page is
810 * always mapped with cache enabled and there is no full cache
811 * coherency across the GART remapping. The unmapping avoids
812 * automatic prefetches from the CPU allocating cache lines in
813 * there. All CPU accesses are done via the direct mapping to
814 * the backing memory. The GART address is only used by PCI
815 * devices.
816 */
817 set_memory_np((unsigned long)__va(iommu_bus_base),
818 iommu_size >> PAGE_SHIFT);
819 /*
820 * Tricky. The GART table remaps the physical memory range,
821 * so the CPU wont notice potential aliases and if the memory
822 * is remapped to UC later on, we might surprise the PCI devices
823 * with a stray writeout of a cacheline. So play it sure and
824 * do an explicit, full-scale wbinvd() _after_ having marked all
825 * the pages as Not-Present:
826 */
827 wbinvd();
828
829 /*
830 * Now all caches are flushed and we can safely enable
831 * GART hardware. Doing it early leaves the possibility
832 * of stale cache entries that can lead to GART PTE
833 * errors.
834 */
835 enable_gart_translations();
836
837 /*
838 * Try to workaround a bug (thanks to BenH):
839 * Set unmapped entries to a scratch page instead of 0.
840 * Any prefetches that hit unmapped entries won't get an bus abort
841 * then. (P2P bridge may be prefetching on DMA reads).
842 */
843 scratch = get_zeroed_page(GFP_KERNEL);
844 if (!scratch)
845 panic("Cannot allocate iommu scratch page");
846 gart_unmapped_entry = GPTE_ENCODE(__pa(scratch));
847 for (i = EMERGENCY_PAGES; i < iommu_pages; i++)
848 iommu_gatt_base[i] = gart_unmapped_entry;
849
850 flush_gart();
851 dma_ops = &gart_dma_ops;
852 x86_platform.iommu_shutdown = gart_iommu_shutdown;
853 swiotlb = 0;
854
855 return 0;
856}
857
858void __init gart_parse_options(char *p)
859{
860 int arg;
861
862#ifdef CONFIG_IOMMU_LEAK
863 if (!strncmp(p, "leak", 4)) {
864 leak_trace = 1;
865 p += 4;
866 if (*p == '=')
867 ++p;
868 if (isdigit(*p) && get_option(&p, &arg))
869 iommu_leak_pages = arg;
870 }
871#endif
872 if (isdigit(*p) && get_option(&p, &arg))
873 iommu_size = arg;
874 if (!strncmp(p, "fullflush", 9))
875 iommu_fullflush = 1;
876 if (!strncmp(p, "nofullflush", 11))
877 iommu_fullflush = 0;
878 if (!strncmp(p, "noagp", 5))
879 no_agp = 1;
880 if (!strncmp(p, "noaperture", 10))
881 fix_aperture = 0;
882 /* duplicated from pci-dma.c */
883 if (!strncmp(p, "force", 5))
884 gart_iommu_aperture_allowed = 1;
885 if (!strncmp(p, "allowed", 7))
886 gart_iommu_aperture_allowed = 1;
887 if (!strncmp(p, "memaper", 7)) {
888 fallback_aper_force = 1;
889 p += 7;
890 if (*p == '=') {
891 ++p;
892 if (get_option(&p, &arg))
893 fallback_aper_order = arg;
894 }
895 }
896}
897IOMMU_INIT_POST(gart_iommu_hole_init);