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Linus Torvalds1da177e2005-04-16 15:20:36 -07001/*
Russell King0ddbccd2008-09-25 15:59:19 +01002 * linux/arch/arm/mm/dma-mapping.c
Linus Torvalds1da177e2005-04-16 15:20:36 -07003 *
4 * Copyright (C) 2000-2004 Russell King
5 *
6 * This program is free software; you can redistribute it and/or modify
7 * it under the terms of the GNU General Public License version 2 as
8 * published by the Free Software Foundation.
9 *
10 * DMA uncached mapping support.
11 */
12#include <linux/module.h>
13#include <linux/mm.h>
Tejun Heo5a0e3ad2010-03-24 17:04:11 +090014#include <linux/gfp.h>
Linus Torvalds1da177e2005-04-16 15:20:36 -070015#include <linux/errno.h>
16#include <linux/list.h>
17#include <linux/init.h>
18#include <linux/device.h>
19#include <linux/dma-mapping.h>
Marek Szyprowskic7909502011-12-29 13:09:51 +010020#include <linux/dma-contiguous.h>
Nicolas Pitre39af22a2010-12-15 15:14:45 -050021#include <linux/highmem.h>
Marek Szyprowskic7909502011-12-29 13:09:51 +010022#include <linux/memblock.h>
Jon Medhurst99d17172011-08-02 17:28:27 +010023#include <linux/slab.h>
Marek Szyprowski4ce63fc2012-05-16 15:48:21 +020024#include <linux/iommu.h>
Marek Szyprowskie9da6e92012-07-30 09:11:33 +020025#include <linux/io.h>
Marek Szyprowski4ce63fc2012-05-16 15:48:21 +020026#include <linux/vmalloc.h>
Linus Torvalds1da177e2005-04-16 15:20:36 -070027
Lennert Buytenhek23759dc2006-04-02 00:07:39 +010028#include <asm/memory.h>
Nicolas Pitre43377452009-03-12 22:52:09 -040029#include <asm/highmem.h>
Linus Torvalds1da177e2005-04-16 15:20:36 -070030#include <asm/cacheflush.h>
Linus Torvalds1da177e2005-04-16 15:20:36 -070031#include <asm/tlbflush.h>
Kevin Hilman37134cd2006-01-12 16:12:21 +000032#include <asm/sizes.h>
Jon Medhurst99d17172011-08-02 17:28:27 +010033#include <asm/mach/arch.h>
Marek Szyprowski4ce63fc2012-05-16 15:48:21 +020034#include <asm/dma-iommu.h>
Marek Szyprowskic7909502011-12-29 13:09:51 +010035#include <asm/mach/map.h>
36#include <asm/system_info.h>
37#include <asm/dma-contiguous.h>
Linus Torvalds1da177e2005-04-16 15:20:36 -070038
Russell King022ae532011-07-08 21:26:59 +010039#include "mm.h"
40
Marek Szyprowski15237e12012-02-10 19:55:20 +010041/*
42 * The DMA API is built upon the notion of "buffer ownership". A buffer
43 * is either exclusively owned by the CPU (and therefore may be accessed
44 * by it) or exclusively owned by the DMA device. These helper functions
45 * represent the transitions between these two ownership states.
46 *
47 * Note, however, that on later ARMs, this notion does not work due to
48 * speculative prefetches. We model our approach on the assumption that
49 * the CPU does do speculative prefetches, which means we clean caches
50 * before transfers and delay cache invalidation until transfer completion.
51 *
Marek Szyprowski15237e12012-02-10 19:55:20 +010052 */
Marek Szyprowski51fde3492012-02-10 19:55:20 +010053static void __dma_page_cpu_to_dev(struct page *, unsigned long,
Marek Szyprowski15237e12012-02-10 19:55:20 +010054 size_t, enum dma_data_direction);
Marek Szyprowski51fde3492012-02-10 19:55:20 +010055static void __dma_page_dev_to_cpu(struct page *, unsigned long,
Marek Szyprowski15237e12012-02-10 19:55:20 +010056 size_t, enum dma_data_direction);
57
Marek Szyprowski2dc6a012012-02-10 19:55:20 +010058/**
59 * arm_dma_map_page - map a portion of a page for streaming DMA
60 * @dev: valid struct device pointer, or NULL for ISA and EISA-like devices
61 * @page: page that buffer resides in
62 * @offset: offset into page for start of buffer
63 * @size: size of buffer to map
64 * @dir: DMA transfer direction
65 *
66 * Ensure that any data held in the cache is appropriately discarded
67 * or written back.
68 *
69 * The device owns this memory once this call has completed. The CPU
70 * can regain ownership by calling dma_unmap_page().
71 */
Marek Szyprowski51fde3492012-02-10 19:55:20 +010072static dma_addr_t arm_dma_map_page(struct device *dev, struct page *page,
Marek Szyprowski2dc6a012012-02-10 19:55:20 +010073 unsigned long offset, size_t size, enum dma_data_direction dir,
74 struct dma_attrs *attrs)
75{
Marek Szyprowski51fde3492012-02-10 19:55:20 +010076 if (!arch_is_coherent())
77 __dma_page_cpu_to_dev(page, offset, size, dir);
78 return pfn_to_dma(dev, page_to_pfn(page)) + offset;
Marek Szyprowski2dc6a012012-02-10 19:55:20 +010079}
80
81/**
82 * arm_dma_unmap_page - unmap a buffer previously mapped through dma_map_page()
83 * @dev: valid struct device pointer, or NULL for ISA and EISA-like devices
84 * @handle: DMA address of buffer
85 * @size: size of buffer (same as passed to dma_map_page)
86 * @dir: DMA transfer direction (same as passed to dma_map_page)
87 *
88 * Unmap a page streaming mode DMA translation. The handle and size
89 * must match what was provided in the previous dma_map_page() call.
90 * All other usages are undefined.
91 *
92 * After this call, reads by the CPU to the buffer are guaranteed to see
93 * whatever the device wrote there.
94 */
Marek Szyprowski51fde3492012-02-10 19:55:20 +010095static void arm_dma_unmap_page(struct device *dev, dma_addr_t handle,
Marek Szyprowski2dc6a012012-02-10 19:55:20 +010096 size_t size, enum dma_data_direction dir,
97 struct dma_attrs *attrs)
98{
Marek Szyprowski51fde3492012-02-10 19:55:20 +010099 if (!arch_is_coherent())
100 __dma_page_dev_to_cpu(pfn_to_page(dma_to_pfn(dev, handle)),
101 handle & ~PAGE_MASK, size, dir);
Marek Szyprowski2dc6a012012-02-10 19:55:20 +0100102}
103
Marek Szyprowski51fde3492012-02-10 19:55:20 +0100104static void arm_dma_sync_single_for_cpu(struct device *dev,
Marek Szyprowski2dc6a012012-02-10 19:55:20 +0100105 dma_addr_t handle, size_t size, enum dma_data_direction dir)
106{
107 unsigned int offset = handle & (PAGE_SIZE - 1);
108 struct page *page = pfn_to_page(dma_to_pfn(dev, handle-offset));
Marek Szyprowski51fde3492012-02-10 19:55:20 +0100109 if (!arch_is_coherent())
110 __dma_page_dev_to_cpu(page, offset, size, dir);
Marek Szyprowski2dc6a012012-02-10 19:55:20 +0100111}
112
Marek Szyprowski51fde3492012-02-10 19:55:20 +0100113static void arm_dma_sync_single_for_device(struct device *dev,
Marek Szyprowski2dc6a012012-02-10 19:55:20 +0100114 dma_addr_t handle, size_t size, enum dma_data_direction dir)
115{
116 unsigned int offset = handle & (PAGE_SIZE - 1);
117 struct page *page = pfn_to_page(dma_to_pfn(dev, handle-offset));
Marek Szyprowski51fde3492012-02-10 19:55:20 +0100118 if (!arch_is_coherent())
119 __dma_page_cpu_to_dev(page, offset, size, dir);
Marek Szyprowski2dc6a012012-02-10 19:55:20 +0100120}
121
122static int arm_dma_set_mask(struct device *dev, u64 dma_mask);
123
124struct dma_map_ops arm_dma_ops = {
Marek Szyprowskif99d6032012-05-16 18:31:23 +0200125 .alloc = arm_dma_alloc,
126 .free = arm_dma_free,
127 .mmap = arm_dma_mmap,
Marek Szyprowski2dc6a012012-02-10 19:55:20 +0100128 .map_page = arm_dma_map_page,
129 .unmap_page = arm_dma_unmap_page,
130 .map_sg = arm_dma_map_sg,
131 .unmap_sg = arm_dma_unmap_sg,
132 .sync_single_for_cpu = arm_dma_sync_single_for_cpu,
133 .sync_single_for_device = arm_dma_sync_single_for_device,
134 .sync_sg_for_cpu = arm_dma_sync_sg_for_cpu,
135 .sync_sg_for_device = arm_dma_sync_sg_for_device,
136 .set_dma_mask = arm_dma_set_mask,
137};
138EXPORT_SYMBOL(arm_dma_ops);
139
Catalin Marinasab6494f2009-07-24 12:35:02 +0100140static u64 get_coherent_dma_mask(struct device *dev)
141{
Russell King022ae532011-07-08 21:26:59 +0100142 u64 mask = (u64)arm_dma_limit;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700143
Catalin Marinasab6494f2009-07-24 12:35:02 +0100144 if (dev) {
145 mask = dev->coherent_dma_mask;
146
147 /*
148 * Sanity check the DMA mask - it must be non-zero, and
149 * must be able to be satisfied by a DMA allocation.
150 */
151 if (mask == 0) {
152 dev_warn(dev, "coherent DMA mask is unset\n");
153 return 0;
154 }
155
Russell King022ae532011-07-08 21:26:59 +0100156 if ((~mask) & (u64)arm_dma_limit) {
Catalin Marinasab6494f2009-07-24 12:35:02 +0100157 dev_warn(dev, "coherent DMA mask %#llx is smaller "
158 "than system GFP_DMA mask %#llx\n",
Russell King022ae532011-07-08 21:26:59 +0100159 mask, (u64)arm_dma_limit);
Catalin Marinasab6494f2009-07-24 12:35:02 +0100160 return 0;
161 }
162 }
163
164 return mask;
165}
166
Marek Szyprowskic7909502011-12-29 13:09:51 +0100167static void __dma_clear_buffer(struct page *page, size_t size)
168{
169 void *ptr;
170 /*
171 * Ensure that the allocated pages are zeroed, and that any data
172 * lurking in the kernel direct-mapped region is invalidated.
173 */
174 ptr = page_address(page);
Marek Szyprowski4ce63fc2012-05-16 15:48:21 +0200175 if (ptr) {
176 memset(ptr, 0, size);
177 dmac_flush_range(ptr, ptr + size);
178 outer_flush_range(__pa(ptr), __pa(ptr) + size);
179 }
Marek Szyprowskic7909502011-12-29 13:09:51 +0100180}
181
Russell King7a9a32a2009-11-19 15:31:07 +0000182/*
183 * Allocate a DMA buffer for 'dev' of size 'size' using the
184 * specified gfp mask. Note that 'size' must be page aligned.
185 */
186static struct page *__dma_alloc_buffer(struct device *dev, size_t size, gfp_t gfp)
187{
188 unsigned long order = get_order(size);
189 struct page *page, *p, *e;
Russell King7a9a32a2009-11-19 15:31:07 +0000190
191 page = alloc_pages(gfp, order);
192 if (!page)
193 return NULL;
194
195 /*
196 * Now split the huge page and free the excess pages
197 */
198 split_page(page, order);
199 for (p = page + (size >> PAGE_SHIFT), e = page + (1 << order); p < e; p++)
200 __free_page(p);
201
Marek Szyprowskic7909502011-12-29 13:09:51 +0100202 __dma_clear_buffer(page, size);
Russell King7a9a32a2009-11-19 15:31:07 +0000203
204 return page;
205}
206
207/*
208 * Free a DMA buffer. 'size' must be page aligned.
209 */
210static void __dma_free_buffer(struct page *page, size_t size)
211{
212 struct page *e = page + (size >> PAGE_SHIFT);
213
214 while (page < e) {
215 __free_page(page);
216 page++;
217 }
218}
219
Catalin Marinasab6494f2009-07-24 12:35:02 +0100220#ifdef CONFIG_MMU
Linus Torvalds1da177e2005-04-16 15:20:36 -0700221#ifdef CONFIG_HUGETLB_PAGE
222#error ARM Coherent DMA allocator does not (yet) support huge TLB
223#endif
224
Marek Szyprowskic7909502011-12-29 13:09:51 +0100225static void *__alloc_from_contiguous(struct device *dev, size_t size,
226 pgprot_t prot, struct page **ret_page);
227
Marek Szyprowskie9da6e92012-07-30 09:11:33 +0200228static void *__alloc_remap_buffer(struct device *dev, size_t size, gfp_t gfp,
229 pgprot_t prot, struct page **ret_page,
230 const void *caller);
231
232static void *
233__dma_alloc_remap(struct page *page, size_t size, gfp_t gfp, pgprot_t prot,
234 const void *caller)
235{
236 struct vm_struct *area;
237 unsigned long addr;
238
239 /*
240 * DMA allocation can be mapped to user space, so lets
241 * set VM_USERMAP flags too.
242 */
243 area = get_vm_area_caller(size, VM_ARM_DMA_CONSISTENT | VM_USERMAP,
244 caller);
245 if (!area)
246 return NULL;
247 addr = (unsigned long)area->addr;
248 area->phys_addr = __pfn_to_phys(page_to_pfn(page));
249
250 if (ioremap_page_range(addr, addr + size, area->phys_addr, prot)) {
251 vunmap((void *)addr);
252 return NULL;
253 }
254 return (void *)addr;
255}
256
257static void __dma_free_remap(void *cpu_addr, size_t size)
258{
259 unsigned int flags = VM_ARM_DMA_CONSISTENT | VM_USERMAP;
260 struct vm_struct *area = find_vm_area(cpu_addr);
261 if (!area || (area->flags & flags) != flags) {
262 WARN(1, "trying to free invalid coherent area: %p\n", cpu_addr);
263 return;
264 }
265 unmap_kernel_range((unsigned long)cpu_addr, size);
266 vunmap(cpu_addr);
267}
268
269struct dma_pool {
270 size_t size;
271 spinlock_t lock;
272 unsigned long *bitmap;
273 unsigned long nr_pages;
274 void *vaddr;
275 struct page *page;
Marek Szyprowskic7909502011-12-29 13:09:51 +0100276};
277
Marek Szyprowskie9da6e92012-07-30 09:11:33 +0200278static struct dma_pool atomic_pool = {
279 .size = SZ_256K,
280};
Marek Szyprowskic7909502011-12-29 13:09:51 +0100281
282static int __init early_coherent_pool(char *p)
283{
Marek Szyprowskie9da6e92012-07-30 09:11:33 +0200284 atomic_pool.size = memparse(p, &p);
Marek Szyprowskic7909502011-12-29 13:09:51 +0100285 return 0;
286}
287early_param("coherent_pool", early_coherent_pool);
288
289/*
290 * Initialise the coherent pool for atomic allocations.
291 */
Marek Szyprowskie9da6e92012-07-30 09:11:33 +0200292static int __init atomic_pool_init(void)
Marek Szyprowskic7909502011-12-29 13:09:51 +0100293{
Marek Szyprowskie9da6e92012-07-30 09:11:33 +0200294 struct dma_pool *pool = &atomic_pool;
Marek Szyprowskic7909502011-12-29 13:09:51 +0100295 pgprot_t prot = pgprot_dmacoherent(pgprot_kernel);
Marek Szyprowskie9da6e92012-07-30 09:11:33 +0200296 unsigned long nr_pages = pool->size >> PAGE_SHIFT;
297 unsigned long *bitmap;
Marek Szyprowskic7909502011-12-29 13:09:51 +0100298 struct page *page;
299 void *ptr;
Marek Szyprowskie9da6e92012-07-30 09:11:33 +0200300 int bitmap_size = BITS_TO_LONGS(nr_pages) * sizeof(long);
Marek Szyprowskic7909502011-12-29 13:09:51 +0100301
Marek Szyprowskie9da6e92012-07-30 09:11:33 +0200302 bitmap = kzalloc(bitmap_size, GFP_KERNEL);
303 if (!bitmap)
304 goto no_bitmap;
Marek Szyprowskic7909502011-12-29 13:09:51 +0100305
Marek Szyprowskie9da6e92012-07-30 09:11:33 +0200306 if (IS_ENABLED(CONFIG_CMA))
307 ptr = __alloc_from_contiguous(NULL, pool->size, prot, &page);
308 else
309 ptr = __alloc_remap_buffer(NULL, pool->size, GFP_KERNEL, prot,
310 &page, NULL);
Marek Szyprowskic7909502011-12-29 13:09:51 +0100311 if (ptr) {
Marek Szyprowskie9da6e92012-07-30 09:11:33 +0200312 spin_lock_init(&pool->lock);
313 pool->vaddr = ptr;
314 pool->page = page;
315 pool->bitmap = bitmap;
316 pool->nr_pages = nr_pages;
317 pr_info("DMA: preallocated %u KiB pool for atomic coherent allocations\n",
318 (unsigned)pool->size / 1024);
Marek Szyprowskic7909502011-12-29 13:09:51 +0100319 return 0;
320 }
Marek Szyprowskie9da6e92012-07-30 09:11:33 +0200321 kfree(bitmap);
322no_bitmap:
323 pr_err("DMA: failed to allocate %u KiB pool for atomic coherent allocation\n",
324 (unsigned)pool->size / 1024);
Marek Szyprowskic7909502011-12-29 13:09:51 +0100325 return -ENOMEM;
326}
327/*
328 * CMA is activated by core_initcall, so we must be called after it.
329 */
Marek Szyprowskie9da6e92012-07-30 09:11:33 +0200330postcore_initcall(atomic_pool_init);
Marek Szyprowskic7909502011-12-29 13:09:51 +0100331
332struct dma_contig_early_reserve {
333 phys_addr_t base;
334 unsigned long size;
335};
336
337static struct dma_contig_early_reserve dma_mmu_remap[MAX_CMA_AREAS] __initdata;
338
339static int dma_mmu_remap_num __initdata;
340
341void __init dma_contiguous_early_fixup(phys_addr_t base, unsigned long size)
342{
343 dma_mmu_remap[dma_mmu_remap_num].base = base;
344 dma_mmu_remap[dma_mmu_remap_num].size = size;
345 dma_mmu_remap_num++;
346}
347
348void __init dma_contiguous_remap(void)
349{
350 int i;
351 for (i = 0; i < dma_mmu_remap_num; i++) {
352 phys_addr_t start = dma_mmu_remap[i].base;
353 phys_addr_t end = start + dma_mmu_remap[i].size;
354 struct map_desc map;
355 unsigned long addr;
356
357 if (end > arm_lowmem_limit)
358 end = arm_lowmem_limit;
359 if (start >= end)
360 return;
361
362 map.pfn = __phys_to_pfn(start);
363 map.virtual = __phys_to_virt(start);
364 map.length = end - start;
365 map.type = MT_MEMORY_DMA_READY;
366
367 /*
368 * Clear previous low-memory mapping
369 */
370 for (addr = __phys_to_virt(start); addr < __phys_to_virt(end);
Vitaly Andrianov61f6c7a2012-05-14 13:49:56 -0400371 addr += PMD_SIZE)
Marek Szyprowskic7909502011-12-29 13:09:51 +0100372 pmd_clear(pmd_off_k(addr));
373
374 iotable_init(&map, 1);
375 }
376}
377
Marek Szyprowskic7909502011-12-29 13:09:51 +0100378static int __dma_update_pte(pte_t *pte, pgtable_t token, unsigned long addr,
379 void *data)
380{
381 struct page *page = virt_to_page(addr);
382 pgprot_t prot = *(pgprot_t *)data;
383
384 set_pte_ext(pte, mk_pte(page, prot), 0);
385 return 0;
386}
387
388static void __dma_remap(struct page *page, size_t size, pgprot_t prot)
389{
390 unsigned long start = (unsigned long) page_address(page);
391 unsigned end = start + size;
392
393 apply_to_page_range(&init_mm, start, size, __dma_update_pte, &prot);
394 dsb();
395 flush_tlb_kernel_range(start, end);
396}
397
398static void *__alloc_remap_buffer(struct device *dev, size_t size, gfp_t gfp,
399 pgprot_t prot, struct page **ret_page,
400 const void *caller)
401{
402 struct page *page;
403 void *ptr;
404 page = __dma_alloc_buffer(dev, size, gfp);
405 if (!page)
406 return NULL;
407
408 ptr = __dma_alloc_remap(page, size, gfp, prot, caller);
409 if (!ptr) {
410 __dma_free_buffer(page, size);
411 return NULL;
412 }
413
414 *ret_page = page;
415 return ptr;
416}
417
Marek Szyprowskie9da6e92012-07-30 09:11:33 +0200418static void *__alloc_from_pool(size_t size, struct page **ret_page)
Marek Szyprowskic7909502011-12-29 13:09:51 +0100419{
Marek Szyprowskie9da6e92012-07-30 09:11:33 +0200420 struct dma_pool *pool = &atomic_pool;
421 unsigned int count = PAGE_ALIGN(size) >> PAGE_SHIFT;
422 unsigned int pageno;
423 unsigned long flags;
424 void *ptr = NULL;
Marek Szyprowskic7909502011-12-29 13:09:51 +0100425 size_t align;
426
Marek Szyprowskie9da6e92012-07-30 09:11:33 +0200427 if (!pool->vaddr) {
428 WARN(1, "coherent pool not initialised!\n");
Marek Szyprowskic7909502011-12-29 13:09:51 +0100429 return NULL;
430 }
431
432 /*
433 * Align the region allocation - allocations from pool are rather
434 * small, so align them to their order in pages, minimum is a page
435 * size. This helps reduce fragmentation of the DMA space.
436 */
437 align = PAGE_SIZE << get_order(size);
Marek Szyprowskie9da6e92012-07-30 09:11:33 +0200438
439 spin_lock_irqsave(&pool->lock, flags);
440 pageno = bitmap_find_next_zero_area(pool->bitmap, pool->nr_pages,
441 0, count, (1 << align) - 1);
442 if (pageno < pool->nr_pages) {
443 bitmap_set(pool->bitmap, pageno, count);
444 ptr = pool->vaddr + PAGE_SIZE * pageno;
445 *ret_page = pool->page + pageno;
Marek Szyprowskic7909502011-12-29 13:09:51 +0100446 }
Marek Szyprowskie9da6e92012-07-30 09:11:33 +0200447 spin_unlock_irqrestore(&pool->lock, flags);
448
449 return ptr;
Marek Szyprowskic7909502011-12-29 13:09:51 +0100450}
451
Marek Szyprowskie9da6e92012-07-30 09:11:33 +0200452static int __free_from_pool(void *start, size_t size)
Marek Szyprowskic7909502011-12-29 13:09:51 +0100453{
Marek Szyprowskie9da6e92012-07-30 09:11:33 +0200454 struct dma_pool *pool = &atomic_pool;
455 unsigned long pageno, count;
456 unsigned long flags;
Marek Szyprowskic7909502011-12-29 13:09:51 +0100457
Marek Szyprowskie9da6e92012-07-30 09:11:33 +0200458 if (start < pool->vaddr || start > pool->vaddr + pool->size)
Marek Szyprowskic7909502011-12-29 13:09:51 +0100459 return 0;
460
Marek Szyprowskie9da6e92012-07-30 09:11:33 +0200461 if (start + size > pool->vaddr + pool->size) {
462 WARN(1, "freeing wrong coherent size from pool\n");
463 return 0;
Marek Szyprowskic7909502011-12-29 13:09:51 +0100464 }
465
Marek Szyprowskie9da6e92012-07-30 09:11:33 +0200466 pageno = (start - pool->vaddr) >> PAGE_SHIFT;
467 count = size >> PAGE_SHIFT;
468
469 spin_lock_irqsave(&pool->lock, flags);
470 bitmap_clear(pool->bitmap, pageno, count);
471 spin_unlock_irqrestore(&pool->lock, flags);
472
Marek Szyprowskic7909502011-12-29 13:09:51 +0100473 return 1;
474}
475
476static void *__alloc_from_contiguous(struct device *dev, size_t size,
477 pgprot_t prot, struct page **ret_page)
478{
479 unsigned long order = get_order(size);
480 size_t count = size >> PAGE_SHIFT;
481 struct page *page;
482
483 page = dma_alloc_from_contiguous(dev, count, order);
484 if (!page)
485 return NULL;
486
487 __dma_clear_buffer(page, size);
488 __dma_remap(page, size, prot);
489
490 *ret_page = page;
491 return page_address(page);
492}
493
494static void __free_from_contiguous(struct device *dev, struct page *page,
495 size_t size)
496{
497 __dma_remap(page, size, pgprot_kernel);
498 dma_release_from_contiguous(dev, page, size >> PAGE_SHIFT);
499}
500
Marek Szyprowskif99d6032012-05-16 18:31:23 +0200501static inline pgprot_t __get_dma_pgprot(struct dma_attrs *attrs, pgprot_t prot)
502{
503 prot = dma_get_attr(DMA_ATTR_WRITE_COMBINE, attrs) ?
504 pgprot_writecombine(prot) :
505 pgprot_dmacoherent(prot);
506 return prot;
507}
508
Marek Szyprowskic7909502011-12-29 13:09:51 +0100509#define nommu() 0
510
Catalin Marinasab6494f2009-07-24 12:35:02 +0100511#else /* !CONFIG_MMU */
Russell King695ae0a2009-11-19 16:31:39 +0000512
Marek Szyprowskic7909502011-12-29 13:09:51 +0100513#define nommu() 1
514
Marek Szyprowskif99d6032012-05-16 18:31:23 +0200515#define __get_dma_pgprot(attrs, prot) __pgprot(0)
Marek Szyprowskic7909502011-12-29 13:09:51 +0100516#define __alloc_remap_buffer(dev, size, gfp, prot, ret, c) NULL
Marek Szyprowskie9da6e92012-07-30 09:11:33 +0200517#define __alloc_from_pool(size, ret_page) NULL
Marek Szyprowskic7909502011-12-29 13:09:51 +0100518#define __alloc_from_contiguous(dev, size, prot, ret) NULL
519#define __free_from_pool(cpu_addr, size) 0
520#define __free_from_contiguous(dev, page, size) do { } while (0)
521#define __dma_free_remap(cpu_addr, size) do { } while (0)
Russell King31ebf942009-11-19 21:12:17 +0000522
523#endif /* CONFIG_MMU */
524
Marek Szyprowskic7909502011-12-29 13:09:51 +0100525static void *__alloc_simple_buffer(struct device *dev, size_t size, gfp_t gfp,
526 struct page **ret_page)
Catalin Marinasab6494f2009-07-24 12:35:02 +0100527{
Russell King04da5692009-11-19 15:54:45 +0000528 struct page *page;
Marek Szyprowskic7909502011-12-29 13:09:51 +0100529 page = __dma_alloc_buffer(dev, size, gfp);
530 if (!page)
531 return NULL;
532
533 *ret_page = page;
534 return page_address(page);
535}
536
537
538
539static void *__dma_alloc(struct device *dev, size_t size, dma_addr_t *handle,
540 gfp_t gfp, pgprot_t prot, const void *caller)
541{
542 u64 mask = get_coherent_dma_mask(dev);
543 struct page *page;
Russell King31ebf942009-11-19 21:12:17 +0000544 void *addr;
Catalin Marinasab6494f2009-07-24 12:35:02 +0100545
Marek Szyprowskic7909502011-12-29 13:09:51 +0100546#ifdef CONFIG_DMA_API_DEBUG
547 u64 limit = (mask + 1) & ~mask;
548 if (limit && size >= limit) {
549 dev_warn(dev, "coherent allocation too big (requested %#x mask %#llx)\n",
550 size, mask);
551 return NULL;
552 }
553#endif
554
555 if (!mask)
556 return NULL;
557
558 if (mask < 0xffffffffULL)
559 gfp |= GFP_DMA;
560
Sumit Bhattacharyaea2e7052011-11-24 00:47:12 +0100561 /*
562 * Following is a work-around (a.k.a. hack) to prevent pages
563 * with __GFP_COMP being passed to split_page() which cannot
564 * handle them. The real problem is that this flag probably
565 * should be 0 on ARM as it is not supported on this
566 * platform; see CONFIG_HUGETLBFS.
567 */
568 gfp &= ~(__GFP_COMP);
569
Marek Szyprowski553ac782012-02-29 14:45:28 +0100570 *handle = DMA_ERROR_CODE;
Russell King04da5692009-11-19 15:54:45 +0000571 size = PAGE_ALIGN(size);
572
Marek Szyprowskic7909502011-12-29 13:09:51 +0100573 if (arch_is_coherent() || nommu())
574 addr = __alloc_simple_buffer(dev, size, gfp, &page);
Marek Szyprowskie9da6e92012-07-30 09:11:33 +0200575 else if (gfp & GFP_ATOMIC)
576 addr = __alloc_from_pool(size, &page);
Marek Szyprowskif1ae98d2012-05-30 10:48:29 +0200577 else if (!IS_ENABLED(CONFIG_CMA))
Marek Szyprowskic7909502011-12-29 13:09:51 +0100578 addr = __alloc_remap_buffer(dev, size, gfp, prot, &page, caller);
Russell King31ebf942009-11-19 21:12:17 +0000579 else
Marek Szyprowskic7909502011-12-29 13:09:51 +0100580 addr = __alloc_from_contiguous(dev, size, prot, &page);
Russell King31ebf942009-11-19 21:12:17 +0000581
582 if (addr)
Russell King9eedd962011-01-03 00:00:17 +0000583 *handle = pfn_to_dma(dev, page_to_pfn(page));
Russell King31ebf942009-11-19 21:12:17 +0000584
585 return addr;
Catalin Marinasab6494f2009-07-24 12:35:02 +0100586}
Russell King695ae0a2009-11-19 16:31:39 +0000587
Linus Torvalds1da177e2005-04-16 15:20:36 -0700588/*
589 * Allocate DMA-coherent memory space and return both the kernel remapped
590 * virtual and bus address for that space.
591 */
Marek Szyprowskif99d6032012-05-16 18:31:23 +0200592void *arm_dma_alloc(struct device *dev, size_t size, dma_addr_t *handle,
593 gfp_t gfp, struct dma_attrs *attrs)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700594{
Marek Szyprowskif99d6032012-05-16 18:31:23 +0200595 pgprot_t prot = __get_dma_pgprot(attrs, pgprot_kernel);
Dmitry Baryshkov1fe53262008-07-18 13:30:14 +0400596 void *memory;
597
598 if (dma_alloc_from_coherent(dev, size, handle, &memory))
599 return memory;
600
Marek Szyprowskif99d6032012-05-16 18:31:23 +0200601 return __dma_alloc(dev, size, handle, gfp, prot,
Russell King45cd5292012-01-12 23:08:07 +0000602 __builtin_return_address(0));
Linus Torvalds1da177e2005-04-16 15:20:36 -0700603}
Linus Torvalds1da177e2005-04-16 15:20:36 -0700604
605/*
Marek Szyprowskif99d6032012-05-16 18:31:23 +0200606 * Create userspace mapping for the DMA-coherent memory.
Linus Torvalds1da177e2005-04-16 15:20:36 -0700607 */
Marek Szyprowskif99d6032012-05-16 18:31:23 +0200608int arm_dma_mmap(struct device *dev, struct vm_area_struct *vma,
609 void *cpu_addr, dma_addr_t dma_addr, size_t size,
610 struct dma_attrs *attrs)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700611{
Catalin Marinasab6494f2009-07-24 12:35:02 +0100612 int ret = -ENXIO;
613#ifdef CONFIG_MMU
Marek Szyprowski50262a42012-07-30 09:35:26 +0200614 unsigned long nr_vma_pages = (vma->vm_end - vma->vm_start) >> PAGE_SHIFT;
615 unsigned long nr_pages = PAGE_ALIGN(size) >> PAGE_SHIFT;
Marek Szyprowskic7909502011-12-29 13:09:51 +0100616 unsigned long pfn = dma_to_pfn(dev, dma_addr);
Marek Szyprowski50262a42012-07-30 09:35:26 +0200617 unsigned long off = vma->vm_pgoff;
618
Marek Szyprowskif99d6032012-05-16 18:31:23 +0200619 vma->vm_page_prot = __get_dma_pgprot(attrs, vma->vm_page_prot);
620
Marek Szyprowski47142f02012-05-15 19:04:13 +0200621 if (dma_mmap_from_coherent(dev, vma, cpu_addr, size, &ret))
622 return ret;
623
Marek Szyprowski50262a42012-07-30 09:35:26 +0200624 if (off < nr_pages && nr_vma_pages <= (nr_pages - off)) {
625 ret = remap_pfn_range(vma, vma->vm_start,
626 pfn + off,
627 vma->vm_end - vma->vm_start,
628 vma->vm_page_prot);
629 }
Catalin Marinasab6494f2009-07-24 12:35:02 +0100630#endif /* CONFIG_MMU */
Linus Torvalds1da177e2005-04-16 15:20:36 -0700631
632 return ret;
633}
634
Linus Torvalds1da177e2005-04-16 15:20:36 -0700635/*
Marek Szyprowskic7909502011-12-29 13:09:51 +0100636 * Free a buffer as defined by the above mapping.
Linus Torvalds1da177e2005-04-16 15:20:36 -0700637 */
Marek Szyprowskif99d6032012-05-16 18:31:23 +0200638void arm_dma_free(struct device *dev, size_t size, void *cpu_addr,
639 dma_addr_t handle, struct dma_attrs *attrs)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700640{
Marek Szyprowskic7909502011-12-29 13:09:51 +0100641 struct page *page = pfn_to_page(dma_to_pfn(dev, handle));
Russell King5edf71a2005-11-25 15:52:51 +0000642
Dmitry Baryshkov1fe53262008-07-18 13:30:14 +0400643 if (dma_release_from_coherent(dev, get_order(size), cpu_addr))
644 return;
645
Russell King3e82d012009-11-19 15:38:12 +0000646 size = PAGE_ALIGN(size);
647
Marek Szyprowskic7909502011-12-29 13:09:51 +0100648 if (arch_is_coherent() || nommu()) {
649 __dma_free_buffer(page, size);
Marek Szyprowskif1ae98d2012-05-30 10:48:29 +0200650 } else if (!IS_ENABLED(CONFIG_CMA)) {
Russell King695ae0a2009-11-19 16:31:39 +0000651 __dma_free_remap(cpu_addr, size);
Marek Szyprowskic7909502011-12-29 13:09:51 +0100652 __dma_free_buffer(page, size);
653 } else {
654 if (__free_from_pool(cpu_addr, size))
655 return;
656 /*
657 * Non-atomic allocations cannot be freed with IRQs disabled
658 */
659 WARN_ON(irqs_disabled());
660 __free_from_contiguous(dev, page, size);
661 }
Linus Torvalds1da177e2005-04-16 15:20:36 -0700662}
Russell Kingafd1a322008-09-25 16:30:57 +0100663
Russell King65af1912009-11-24 17:53:33 +0000664static void dma_cache_maint_page(struct page *page, unsigned long offset,
Russell Kinga9c91472009-11-26 16:19:58 +0000665 size_t size, enum dma_data_direction dir,
666 void (*op)(const void *, size_t, int))
Russell King65af1912009-11-24 17:53:33 +0000667{
668 /*
669 * A single sg entry may refer to multiple physically contiguous
670 * pages. But we still need to process highmem pages individually.
671 * If highmem is not configured then the bulk of this loop gets
672 * optimized out.
673 */
674 size_t left = size;
675 do {
676 size_t len = left;
Russell King93f1d622009-11-24 14:41:01 +0000677 void *vaddr;
678
679 if (PageHighMem(page)) {
680 if (len + offset > PAGE_SIZE) {
681 if (offset >= PAGE_SIZE) {
682 page += offset / PAGE_SIZE;
683 offset %= PAGE_SIZE;
684 }
685 len = PAGE_SIZE - offset;
Russell King65af1912009-11-24 17:53:33 +0000686 }
Russell King93f1d622009-11-24 14:41:01 +0000687 vaddr = kmap_high_get(page);
688 if (vaddr) {
689 vaddr += offset;
Russell Kinga9c91472009-11-26 16:19:58 +0000690 op(vaddr, len, dir);
Russell King93f1d622009-11-24 14:41:01 +0000691 kunmap_high(page);
Nicolas Pitre7e5a69e2010-03-29 21:46:02 +0100692 } else if (cache_is_vipt()) {
Nicolas Pitre39af22a2010-12-15 15:14:45 -0500693 /* unmapped pages might still be cached */
694 vaddr = kmap_atomic(page);
Nicolas Pitre7e5a69e2010-03-29 21:46:02 +0100695 op(vaddr + offset, len, dir);
Nicolas Pitre39af22a2010-12-15 15:14:45 -0500696 kunmap_atomic(vaddr);
Russell King93f1d622009-11-24 14:41:01 +0000697 }
698 } else {
699 vaddr = page_address(page) + offset;
Russell Kinga9c91472009-11-26 16:19:58 +0000700 op(vaddr, len, dir);
Russell King65af1912009-11-24 17:53:33 +0000701 }
Russell King65af1912009-11-24 17:53:33 +0000702 offset = 0;
703 page++;
704 left -= len;
705 } while (left);
706}
707
Marek Szyprowski51fde3492012-02-10 19:55:20 +0100708/*
709 * Make an area consistent for devices.
710 * Note: Drivers should NOT use this function directly, as it will break
711 * platforms with CONFIG_DMABOUNCE.
712 * Use the driver DMA support - see dma-mapping.h (dma_sync_*)
713 */
714static void __dma_page_cpu_to_dev(struct page *page, unsigned long off,
Russell King65af1912009-11-24 17:53:33 +0000715 size_t size, enum dma_data_direction dir)
716{
Nicolas Pitre43377452009-03-12 22:52:09 -0400717 unsigned long paddr;
Nicolas Pitre43377452009-03-12 22:52:09 -0400718
Russell Kinga9c91472009-11-26 16:19:58 +0000719 dma_cache_maint_page(page, off, size, dir, dmac_map_area);
Nicolas Pitre43377452009-03-12 22:52:09 -0400720
Russell King65af1912009-11-24 17:53:33 +0000721 paddr = page_to_phys(page) + off;
Russell King2ffe2da2009-10-31 16:52:16 +0000722 if (dir == DMA_FROM_DEVICE) {
723 outer_inv_range(paddr, paddr + size);
724 } else {
725 outer_clean_range(paddr, paddr + size);
726 }
727 /* FIXME: non-speculating: flush on bidirectional mappings? */
Nicolas Pitre43377452009-03-12 22:52:09 -0400728}
Russell King4ea0d732009-11-24 16:27:17 +0000729
Marek Szyprowski51fde3492012-02-10 19:55:20 +0100730static void __dma_page_dev_to_cpu(struct page *page, unsigned long off,
Russell King4ea0d732009-11-24 16:27:17 +0000731 size_t size, enum dma_data_direction dir)
732{
Russell King2ffe2da2009-10-31 16:52:16 +0000733 unsigned long paddr = page_to_phys(page) + off;
734
735 /* FIXME: non-speculating: not required */
736 /* don't bother invalidating if DMA to device */
737 if (dir != DMA_TO_DEVICE)
738 outer_inv_range(paddr, paddr + size);
739
Russell Kinga9c91472009-11-26 16:19:58 +0000740 dma_cache_maint_page(page, off, size, dir, dmac_unmap_area);
Catalin Marinasc0177802010-09-13 15:57:36 +0100741
742 /*
743 * Mark the D-cache clean for this page to avoid extra flushing.
744 */
745 if (dir != DMA_TO_DEVICE && off == 0 && size >= PAGE_SIZE)
746 set_bit(PG_dcache_clean, &page->flags);
Russell King4ea0d732009-11-24 16:27:17 +0000747}
Nicolas Pitre43377452009-03-12 22:52:09 -0400748
Russell Kingafd1a322008-09-25 16:30:57 +0100749/**
Marek Szyprowski2a550e72012-02-10 19:55:20 +0100750 * arm_dma_map_sg - map a set of SG buffers for streaming mode DMA
Russell Kingafd1a322008-09-25 16:30:57 +0100751 * @dev: valid struct device pointer, or NULL for ISA and EISA-like devices
752 * @sg: list of buffers
753 * @nents: number of buffers to map
754 * @dir: DMA transfer direction
755 *
756 * Map a set of buffers described by scatterlist in streaming mode for DMA.
757 * This is the scatter-gather version of the dma_map_single interface.
758 * Here the scatter gather list elements are each tagged with the
759 * appropriate dma address and length. They are obtained via
760 * sg_dma_{address,length}.
761 *
762 * Device ownership issues as mentioned for dma_map_single are the same
763 * here.
764 */
Marek Szyprowski2dc6a012012-02-10 19:55:20 +0100765int arm_dma_map_sg(struct device *dev, struct scatterlist *sg, int nents,
766 enum dma_data_direction dir, struct dma_attrs *attrs)
Russell Kingafd1a322008-09-25 16:30:57 +0100767{
Marek Szyprowski2a550e72012-02-10 19:55:20 +0100768 struct dma_map_ops *ops = get_dma_ops(dev);
Russell Kingafd1a322008-09-25 16:30:57 +0100769 struct scatterlist *s;
Russell King01135d922008-09-25 21:05:02 +0100770 int i, j;
Russell Kingafd1a322008-09-25 16:30:57 +0100771
772 for_each_sg(sg, s, nents, i) {
Marek Szyprowski4ce63fc2012-05-16 15:48:21 +0200773#ifdef CONFIG_NEED_SG_DMA_LENGTH
774 s->dma_length = s->length;
775#endif
Marek Szyprowski2a550e72012-02-10 19:55:20 +0100776 s->dma_address = ops->map_page(dev, sg_page(s), s->offset,
777 s->length, dir, attrs);
Russell King01135d922008-09-25 21:05:02 +0100778 if (dma_mapping_error(dev, s->dma_address))
779 goto bad_mapping;
Russell Kingafd1a322008-09-25 16:30:57 +0100780 }
Russell Kingafd1a322008-09-25 16:30:57 +0100781 return nents;
Russell King01135d922008-09-25 21:05:02 +0100782
783 bad_mapping:
784 for_each_sg(sg, s, i, j)
Marek Szyprowski2a550e72012-02-10 19:55:20 +0100785 ops->unmap_page(dev, sg_dma_address(s), sg_dma_len(s), dir, attrs);
Russell King01135d922008-09-25 21:05:02 +0100786 return 0;
Russell Kingafd1a322008-09-25 16:30:57 +0100787}
Russell Kingafd1a322008-09-25 16:30:57 +0100788
789/**
Marek Szyprowski2a550e72012-02-10 19:55:20 +0100790 * arm_dma_unmap_sg - unmap a set of SG buffers mapped by dma_map_sg
Russell Kingafd1a322008-09-25 16:30:57 +0100791 * @dev: valid struct device pointer, or NULL for ISA and EISA-like devices
792 * @sg: list of buffers
Linus Walleij0adfca62011-01-12 18:50:37 +0100793 * @nents: number of buffers to unmap (same as was passed to dma_map_sg)
Russell Kingafd1a322008-09-25 16:30:57 +0100794 * @dir: DMA transfer direction (same as was passed to dma_map_sg)
795 *
796 * Unmap a set of streaming mode DMA translations. Again, CPU access
797 * rules concerning calls here are the same as for dma_unmap_single().
798 */
Marek Szyprowski2dc6a012012-02-10 19:55:20 +0100799void arm_dma_unmap_sg(struct device *dev, struct scatterlist *sg, int nents,
800 enum dma_data_direction dir, struct dma_attrs *attrs)
Russell Kingafd1a322008-09-25 16:30:57 +0100801{
Marek Szyprowski2a550e72012-02-10 19:55:20 +0100802 struct dma_map_ops *ops = get_dma_ops(dev);
Russell King01135d922008-09-25 21:05:02 +0100803 struct scatterlist *s;
Russell King01135d922008-09-25 21:05:02 +0100804
Russell King01135d922008-09-25 21:05:02 +0100805 int i;
Russell King24056f52011-01-03 11:29:28 +0000806
Russell King01135d922008-09-25 21:05:02 +0100807 for_each_sg(sg, s, nents, i)
Marek Szyprowski2a550e72012-02-10 19:55:20 +0100808 ops->unmap_page(dev, sg_dma_address(s), sg_dma_len(s), dir, attrs);
Russell Kingafd1a322008-09-25 16:30:57 +0100809}
Russell Kingafd1a322008-09-25 16:30:57 +0100810
811/**
Marek Szyprowski2a550e72012-02-10 19:55:20 +0100812 * arm_dma_sync_sg_for_cpu
Russell Kingafd1a322008-09-25 16:30:57 +0100813 * @dev: valid struct device pointer, or NULL for ISA and EISA-like devices
814 * @sg: list of buffers
815 * @nents: number of buffers to map (returned from dma_map_sg)
816 * @dir: DMA transfer direction (same as was passed to dma_map_sg)
817 */
Marek Szyprowski2dc6a012012-02-10 19:55:20 +0100818void arm_dma_sync_sg_for_cpu(struct device *dev, struct scatterlist *sg,
Russell Kingafd1a322008-09-25 16:30:57 +0100819 int nents, enum dma_data_direction dir)
820{
Marek Szyprowski2a550e72012-02-10 19:55:20 +0100821 struct dma_map_ops *ops = get_dma_ops(dev);
Russell Kingafd1a322008-09-25 16:30:57 +0100822 struct scatterlist *s;
823 int i;
824
Marek Szyprowski2a550e72012-02-10 19:55:20 +0100825 for_each_sg(sg, s, nents, i)
826 ops->sync_single_for_cpu(dev, sg_dma_address(s), s->length,
827 dir);
Russell Kingafd1a322008-09-25 16:30:57 +0100828}
Russell Kingafd1a322008-09-25 16:30:57 +0100829
830/**
Marek Szyprowski2a550e72012-02-10 19:55:20 +0100831 * arm_dma_sync_sg_for_device
Russell Kingafd1a322008-09-25 16:30:57 +0100832 * @dev: valid struct device pointer, or NULL for ISA and EISA-like devices
833 * @sg: list of buffers
834 * @nents: number of buffers to map (returned from dma_map_sg)
835 * @dir: DMA transfer direction (same as was passed to dma_map_sg)
836 */
Marek Szyprowski2dc6a012012-02-10 19:55:20 +0100837void arm_dma_sync_sg_for_device(struct device *dev, struct scatterlist *sg,
Russell Kingafd1a322008-09-25 16:30:57 +0100838 int nents, enum dma_data_direction dir)
839{
Marek Szyprowski2a550e72012-02-10 19:55:20 +0100840 struct dma_map_ops *ops = get_dma_ops(dev);
Russell Kingafd1a322008-09-25 16:30:57 +0100841 struct scatterlist *s;
842 int i;
843
Marek Szyprowski2a550e72012-02-10 19:55:20 +0100844 for_each_sg(sg, s, nents, i)
845 ops->sync_single_for_device(dev, sg_dma_address(s), s->length,
846 dir);
Russell Kingafd1a322008-09-25 16:30:57 +0100847}
Russell King24056f52011-01-03 11:29:28 +0000848
Russell King022ae532011-07-08 21:26:59 +0100849/*
850 * Return whether the given device DMA address mask can be supported
851 * properly. For example, if your device can only drive the low 24-bits
852 * during bus mastering, then you would pass 0x00ffffff as the mask
853 * to this function.
854 */
855int dma_supported(struct device *dev, u64 mask)
856{
857 if (mask < (u64)arm_dma_limit)
858 return 0;
859 return 1;
860}
861EXPORT_SYMBOL(dma_supported);
862
Marek Szyprowski2dc6a012012-02-10 19:55:20 +0100863static int arm_dma_set_mask(struct device *dev, u64 dma_mask)
Russell King022ae532011-07-08 21:26:59 +0100864{
865 if (!dev->dma_mask || !dma_supported(dev, dma_mask))
866 return -EIO;
867
Russell King022ae532011-07-08 21:26:59 +0100868 *dev->dma_mask = dma_mask;
Russell King022ae532011-07-08 21:26:59 +0100869
870 return 0;
871}
Russell King022ae532011-07-08 21:26:59 +0100872
Russell King24056f52011-01-03 11:29:28 +0000873#define PREALLOC_DMA_DEBUG_ENTRIES 4096
874
875static int __init dma_debug_do_init(void)
876{
877 dma_debug_init(PREALLOC_DMA_DEBUG_ENTRIES);
878 return 0;
879}
880fs_initcall(dma_debug_do_init);
Marek Szyprowski4ce63fc2012-05-16 15:48:21 +0200881
882#ifdef CONFIG_ARM_DMA_USE_IOMMU
883
884/* IOMMU */
885
886static inline dma_addr_t __alloc_iova(struct dma_iommu_mapping *mapping,
887 size_t size)
888{
889 unsigned int order = get_order(size);
890 unsigned int align = 0;
891 unsigned int count, start;
892 unsigned long flags;
893
894 count = ((PAGE_ALIGN(size) >> PAGE_SHIFT) +
895 (1 << mapping->order) - 1) >> mapping->order;
896
897 if (order > mapping->order)
898 align = (1 << (order - mapping->order)) - 1;
899
900 spin_lock_irqsave(&mapping->lock, flags);
901 start = bitmap_find_next_zero_area(mapping->bitmap, mapping->bits, 0,
902 count, align);
903 if (start > mapping->bits) {
904 spin_unlock_irqrestore(&mapping->lock, flags);
905 return DMA_ERROR_CODE;
906 }
907
908 bitmap_set(mapping->bitmap, start, count);
909 spin_unlock_irqrestore(&mapping->lock, flags);
910
911 return mapping->base + (start << (mapping->order + PAGE_SHIFT));
912}
913
914static inline void __free_iova(struct dma_iommu_mapping *mapping,
915 dma_addr_t addr, size_t size)
916{
917 unsigned int start = (addr - mapping->base) >>
918 (mapping->order + PAGE_SHIFT);
919 unsigned int count = ((size >> PAGE_SHIFT) +
920 (1 << mapping->order) - 1) >> mapping->order;
921 unsigned long flags;
922
923 spin_lock_irqsave(&mapping->lock, flags);
924 bitmap_clear(mapping->bitmap, start, count);
925 spin_unlock_irqrestore(&mapping->lock, flags);
926}
927
928static struct page **__iommu_alloc_buffer(struct device *dev, size_t size, gfp_t gfp)
929{
930 struct page **pages;
931 int count = size >> PAGE_SHIFT;
932 int array_size = count * sizeof(struct page *);
933 int i = 0;
934
935 if (array_size <= PAGE_SIZE)
936 pages = kzalloc(array_size, gfp);
937 else
938 pages = vzalloc(array_size);
939 if (!pages)
940 return NULL;
941
942 while (count) {
Marek Szyprowski593f4732012-06-21 11:48:11 +0200943 int j, order = __fls(count);
Marek Szyprowski4ce63fc2012-05-16 15:48:21 +0200944
945 pages[i] = alloc_pages(gfp | __GFP_NOWARN, order);
946 while (!pages[i] && order)
947 pages[i] = alloc_pages(gfp | __GFP_NOWARN, --order);
948 if (!pages[i])
949 goto error;
950
951 if (order)
952 split_page(pages[i], order);
953 j = 1 << order;
954 while (--j)
955 pages[i + j] = pages[i] + j;
956
957 __dma_clear_buffer(pages[i], PAGE_SIZE << order);
958 i += 1 << order;
959 count -= 1 << order;
960 }
961
962 return pages;
963error:
964 while (--i)
965 if (pages[i])
966 __free_pages(pages[i], 0);
Prathyush K46c87852012-07-16 08:59:55 +0200967 if (array_size <= PAGE_SIZE)
Marek Szyprowski4ce63fc2012-05-16 15:48:21 +0200968 kfree(pages);
969 else
970 vfree(pages);
971 return NULL;
972}
973
974static int __iommu_free_buffer(struct device *dev, struct page **pages, size_t size)
975{
976 int count = size >> PAGE_SHIFT;
977 int array_size = count * sizeof(struct page *);
978 int i;
979 for (i = 0; i < count; i++)
980 if (pages[i])
981 __free_pages(pages[i], 0);
Prathyush K46c87852012-07-16 08:59:55 +0200982 if (array_size <= PAGE_SIZE)
Marek Szyprowski4ce63fc2012-05-16 15:48:21 +0200983 kfree(pages);
984 else
985 vfree(pages);
986 return 0;
987}
988
989/*
990 * Create a CPU mapping for a specified pages
991 */
992static void *
Marek Szyprowskie9da6e92012-07-30 09:11:33 +0200993__iommu_alloc_remap(struct page **pages, size_t size, gfp_t gfp, pgprot_t prot,
994 const void *caller)
Marek Szyprowski4ce63fc2012-05-16 15:48:21 +0200995{
Marek Szyprowskie9da6e92012-07-30 09:11:33 +0200996 unsigned int i, nr_pages = PAGE_ALIGN(size) >> PAGE_SHIFT;
997 struct vm_struct *area;
998 unsigned long p;
Marek Szyprowski4ce63fc2012-05-16 15:48:21 +0200999
Marek Szyprowskie9da6e92012-07-30 09:11:33 +02001000 area = get_vm_area_caller(size, VM_ARM_DMA_CONSISTENT | VM_USERMAP,
1001 caller);
1002 if (!area)
Marek Szyprowski4ce63fc2012-05-16 15:48:21 +02001003 return NULL;
Marek Szyprowskie9da6e92012-07-30 09:11:33 +02001004
1005 area->pages = pages;
1006 area->nr_pages = nr_pages;
1007 p = (unsigned long)area->addr;
1008
1009 for (i = 0; i < nr_pages; i++) {
1010 phys_addr_t phys = __pfn_to_phys(page_to_pfn(pages[i]));
1011 if (ioremap_page_range(p, p + PAGE_SIZE, phys, prot))
1012 goto err;
1013 p += PAGE_SIZE;
Marek Szyprowski4ce63fc2012-05-16 15:48:21 +02001014 }
Marek Szyprowskie9da6e92012-07-30 09:11:33 +02001015 return area->addr;
1016err:
1017 unmap_kernel_range((unsigned long)area->addr, size);
1018 vunmap(area->addr);
Marek Szyprowski4ce63fc2012-05-16 15:48:21 +02001019 return NULL;
1020}
1021
1022/*
1023 * Create a mapping in device IO address space for specified pages
1024 */
1025static dma_addr_t
1026__iommu_create_mapping(struct device *dev, struct page **pages, size_t size)
1027{
1028 struct dma_iommu_mapping *mapping = dev->archdata.mapping;
1029 unsigned int count = PAGE_ALIGN(size) >> PAGE_SHIFT;
1030 dma_addr_t dma_addr, iova;
1031 int i, ret = DMA_ERROR_CODE;
1032
1033 dma_addr = __alloc_iova(mapping, size);
1034 if (dma_addr == DMA_ERROR_CODE)
1035 return dma_addr;
1036
1037 iova = dma_addr;
1038 for (i = 0; i < count; ) {
1039 unsigned int next_pfn = page_to_pfn(pages[i]) + 1;
1040 phys_addr_t phys = page_to_phys(pages[i]);
1041 unsigned int len, j;
1042
1043 for (j = i + 1; j < count; j++, next_pfn++)
1044 if (page_to_pfn(pages[j]) != next_pfn)
1045 break;
1046
1047 len = (j - i) << PAGE_SHIFT;
1048 ret = iommu_map(mapping->domain, iova, phys, len, 0);
1049 if (ret < 0)
1050 goto fail;
1051 iova += len;
1052 i = j;
1053 }
1054 return dma_addr;
1055fail:
1056 iommu_unmap(mapping->domain, dma_addr, iova-dma_addr);
1057 __free_iova(mapping, dma_addr, size);
1058 return DMA_ERROR_CODE;
1059}
1060
1061static int __iommu_remove_mapping(struct device *dev, dma_addr_t iova, size_t size)
1062{
1063 struct dma_iommu_mapping *mapping = dev->archdata.mapping;
1064
1065 /*
1066 * add optional in-page offset from iova to size and align
1067 * result to page size
1068 */
1069 size = PAGE_ALIGN((iova & ~PAGE_MASK) + size);
1070 iova &= PAGE_MASK;
1071
1072 iommu_unmap(mapping->domain, iova, size);
1073 __free_iova(mapping, iova, size);
1074 return 0;
1075}
1076
Marek Szyprowskie9da6e92012-07-30 09:11:33 +02001077static struct page **__iommu_get_pages(void *cpu_addr)
1078{
1079 struct vm_struct *area;
1080
1081 area = find_vm_area(cpu_addr);
1082 if (area && (area->flags & VM_ARM_DMA_CONSISTENT))
1083 return area->pages;
1084 return NULL;
1085}
1086
Marek Szyprowski4ce63fc2012-05-16 15:48:21 +02001087static void *arm_iommu_alloc_attrs(struct device *dev, size_t size,
1088 dma_addr_t *handle, gfp_t gfp, struct dma_attrs *attrs)
1089{
1090 pgprot_t prot = __get_dma_pgprot(attrs, pgprot_kernel);
1091 struct page **pages;
1092 void *addr = NULL;
1093
1094 *handle = DMA_ERROR_CODE;
1095 size = PAGE_ALIGN(size);
1096
1097 pages = __iommu_alloc_buffer(dev, size, gfp);
1098 if (!pages)
1099 return NULL;
1100
1101 *handle = __iommu_create_mapping(dev, pages, size);
1102 if (*handle == DMA_ERROR_CODE)
1103 goto err_buffer;
1104
Marek Szyprowskie9da6e92012-07-30 09:11:33 +02001105 addr = __iommu_alloc_remap(pages, size, gfp, prot,
1106 __builtin_return_address(0));
Marek Szyprowski4ce63fc2012-05-16 15:48:21 +02001107 if (!addr)
1108 goto err_mapping;
1109
1110 return addr;
1111
1112err_mapping:
1113 __iommu_remove_mapping(dev, *handle, size);
1114err_buffer:
1115 __iommu_free_buffer(dev, pages, size);
1116 return NULL;
1117}
1118
1119static int arm_iommu_mmap_attrs(struct device *dev, struct vm_area_struct *vma,
1120 void *cpu_addr, dma_addr_t dma_addr, size_t size,
1121 struct dma_attrs *attrs)
1122{
Marek Szyprowskie9da6e92012-07-30 09:11:33 +02001123 unsigned long uaddr = vma->vm_start;
1124 unsigned long usize = vma->vm_end - vma->vm_start;
1125 struct page **pages = __iommu_get_pages(cpu_addr);
Marek Szyprowski4ce63fc2012-05-16 15:48:21 +02001126
1127 vma->vm_page_prot = __get_dma_pgprot(attrs, vma->vm_page_prot);
Marek Szyprowski4ce63fc2012-05-16 15:48:21 +02001128
Marek Szyprowskie9da6e92012-07-30 09:11:33 +02001129 if (!pages)
1130 return -ENXIO;
Marek Szyprowski4ce63fc2012-05-16 15:48:21 +02001131
Marek Szyprowskie9da6e92012-07-30 09:11:33 +02001132 do {
1133 int ret = vm_insert_page(vma, uaddr, *pages++);
1134 if (ret) {
1135 pr_err("Remapping memory failed: %d\n", ret);
1136 return ret;
1137 }
1138 uaddr += PAGE_SIZE;
1139 usize -= PAGE_SIZE;
1140 } while (usize > 0);
Marek Szyprowski4ce63fc2012-05-16 15:48:21 +02001141
Marek Szyprowski4ce63fc2012-05-16 15:48:21 +02001142 return 0;
1143}
1144
1145/*
1146 * free a page as defined by the above mapping.
1147 * Must not be called with IRQs disabled.
1148 */
1149void arm_iommu_free_attrs(struct device *dev, size_t size, void *cpu_addr,
1150 dma_addr_t handle, struct dma_attrs *attrs)
1151{
Marek Szyprowskie9da6e92012-07-30 09:11:33 +02001152 struct page **pages = __iommu_get_pages(cpu_addr);
Marek Szyprowski4ce63fc2012-05-16 15:48:21 +02001153 size = PAGE_ALIGN(size);
1154
Marek Szyprowskie9da6e92012-07-30 09:11:33 +02001155 if (!pages) {
1156 WARN(1, "trying to free invalid coherent area: %p\n", cpu_addr);
1157 return;
Marek Szyprowski4ce63fc2012-05-16 15:48:21 +02001158 }
Marek Szyprowskie9da6e92012-07-30 09:11:33 +02001159
1160 unmap_kernel_range((unsigned long)cpu_addr, size);
1161 vunmap(cpu_addr);
1162
1163 __iommu_remove_mapping(dev, handle, size);
1164 __iommu_free_buffer(dev, pages, size);
Marek Szyprowski4ce63fc2012-05-16 15:48:21 +02001165}
1166
1167/*
1168 * Map a part of the scatter-gather list into contiguous io address space
1169 */
1170static int __map_sg_chunk(struct device *dev, struct scatterlist *sg,
1171 size_t size, dma_addr_t *handle,
1172 enum dma_data_direction dir)
1173{
1174 struct dma_iommu_mapping *mapping = dev->archdata.mapping;
1175 dma_addr_t iova, iova_base;
1176 int ret = 0;
1177 unsigned int count;
1178 struct scatterlist *s;
1179
1180 size = PAGE_ALIGN(size);
1181 *handle = DMA_ERROR_CODE;
1182
1183 iova_base = iova = __alloc_iova(mapping, size);
1184 if (iova == DMA_ERROR_CODE)
1185 return -ENOMEM;
1186
1187 for (count = 0, s = sg; count < (size >> PAGE_SHIFT); s = sg_next(s)) {
1188 phys_addr_t phys = page_to_phys(sg_page(s));
1189 unsigned int len = PAGE_ALIGN(s->offset + s->length);
1190
1191 if (!arch_is_coherent())
1192 __dma_page_cpu_to_dev(sg_page(s), s->offset, s->length, dir);
1193
1194 ret = iommu_map(mapping->domain, iova, phys, len, 0);
1195 if (ret < 0)
1196 goto fail;
1197 count += len >> PAGE_SHIFT;
1198 iova += len;
1199 }
1200 *handle = iova_base;
1201
1202 return 0;
1203fail:
1204 iommu_unmap(mapping->domain, iova_base, count * PAGE_SIZE);
1205 __free_iova(mapping, iova_base, size);
1206 return ret;
1207}
1208
1209/**
1210 * arm_iommu_map_sg - map a set of SG buffers for streaming mode DMA
1211 * @dev: valid struct device pointer
1212 * @sg: list of buffers
1213 * @nents: number of buffers to map
1214 * @dir: DMA transfer direction
1215 *
1216 * Map a set of buffers described by scatterlist in streaming mode for DMA.
1217 * The scatter gather list elements are merged together (if possible) and
1218 * tagged with the appropriate dma address and length. They are obtained via
1219 * sg_dma_{address,length}.
1220 */
1221int arm_iommu_map_sg(struct device *dev, struct scatterlist *sg, int nents,
1222 enum dma_data_direction dir, struct dma_attrs *attrs)
1223{
1224 struct scatterlist *s = sg, *dma = sg, *start = sg;
1225 int i, count = 0;
1226 unsigned int offset = s->offset;
1227 unsigned int size = s->offset + s->length;
1228 unsigned int max = dma_get_max_seg_size(dev);
1229
1230 for (i = 1; i < nents; i++) {
1231 s = sg_next(s);
1232
1233 s->dma_address = DMA_ERROR_CODE;
1234 s->dma_length = 0;
1235
1236 if (s->offset || (size & ~PAGE_MASK) || size + s->length > max) {
1237 if (__map_sg_chunk(dev, start, size, &dma->dma_address,
1238 dir) < 0)
1239 goto bad_mapping;
1240
1241 dma->dma_address += offset;
1242 dma->dma_length = size - offset;
1243
1244 size = offset = s->offset;
1245 start = s;
1246 dma = sg_next(dma);
1247 count += 1;
1248 }
1249 size += s->length;
1250 }
1251 if (__map_sg_chunk(dev, start, size, &dma->dma_address, dir) < 0)
1252 goto bad_mapping;
1253
1254 dma->dma_address += offset;
1255 dma->dma_length = size - offset;
1256
1257 return count+1;
1258
1259bad_mapping:
1260 for_each_sg(sg, s, count, i)
1261 __iommu_remove_mapping(dev, sg_dma_address(s), sg_dma_len(s));
1262 return 0;
1263}
1264
1265/**
1266 * arm_iommu_unmap_sg - unmap a set of SG buffers mapped by dma_map_sg
1267 * @dev: valid struct device pointer
1268 * @sg: list of buffers
1269 * @nents: number of buffers to unmap (same as was passed to dma_map_sg)
1270 * @dir: DMA transfer direction (same as was passed to dma_map_sg)
1271 *
1272 * Unmap a set of streaming mode DMA translations. Again, CPU access
1273 * rules concerning calls here are the same as for dma_unmap_single().
1274 */
1275void arm_iommu_unmap_sg(struct device *dev, struct scatterlist *sg, int nents,
1276 enum dma_data_direction dir, struct dma_attrs *attrs)
1277{
1278 struct scatterlist *s;
1279 int i;
1280
1281 for_each_sg(sg, s, nents, i) {
1282 if (sg_dma_len(s))
1283 __iommu_remove_mapping(dev, sg_dma_address(s),
1284 sg_dma_len(s));
1285 if (!arch_is_coherent())
1286 __dma_page_dev_to_cpu(sg_page(s), s->offset,
1287 s->length, dir);
1288 }
1289}
1290
1291/**
1292 * arm_iommu_sync_sg_for_cpu
1293 * @dev: valid struct device pointer
1294 * @sg: list of buffers
1295 * @nents: number of buffers to map (returned from dma_map_sg)
1296 * @dir: DMA transfer direction (same as was passed to dma_map_sg)
1297 */
1298void arm_iommu_sync_sg_for_cpu(struct device *dev, struct scatterlist *sg,
1299 int nents, enum dma_data_direction dir)
1300{
1301 struct scatterlist *s;
1302 int i;
1303
1304 for_each_sg(sg, s, nents, i)
1305 if (!arch_is_coherent())
1306 __dma_page_dev_to_cpu(sg_page(s), s->offset, s->length, dir);
1307
1308}
1309
1310/**
1311 * arm_iommu_sync_sg_for_device
1312 * @dev: valid struct device pointer
1313 * @sg: list of buffers
1314 * @nents: number of buffers to map (returned from dma_map_sg)
1315 * @dir: DMA transfer direction (same as was passed to dma_map_sg)
1316 */
1317void arm_iommu_sync_sg_for_device(struct device *dev, struct scatterlist *sg,
1318 int nents, enum dma_data_direction dir)
1319{
1320 struct scatterlist *s;
1321 int i;
1322
1323 for_each_sg(sg, s, nents, i)
1324 if (!arch_is_coherent())
1325 __dma_page_cpu_to_dev(sg_page(s), s->offset, s->length, dir);
1326}
1327
1328
1329/**
1330 * arm_iommu_map_page
1331 * @dev: valid struct device pointer
1332 * @page: page that buffer resides in
1333 * @offset: offset into page for start of buffer
1334 * @size: size of buffer to map
1335 * @dir: DMA transfer direction
1336 *
1337 * IOMMU aware version of arm_dma_map_page()
1338 */
1339static dma_addr_t arm_iommu_map_page(struct device *dev, struct page *page,
1340 unsigned long offset, size_t size, enum dma_data_direction dir,
1341 struct dma_attrs *attrs)
1342{
1343 struct dma_iommu_mapping *mapping = dev->archdata.mapping;
1344 dma_addr_t dma_addr;
1345 int ret, len = PAGE_ALIGN(size + offset);
1346
1347 if (!arch_is_coherent())
1348 __dma_page_cpu_to_dev(page, offset, size, dir);
1349
1350 dma_addr = __alloc_iova(mapping, len);
1351 if (dma_addr == DMA_ERROR_CODE)
1352 return dma_addr;
1353
1354 ret = iommu_map(mapping->domain, dma_addr, page_to_phys(page), len, 0);
1355 if (ret < 0)
1356 goto fail;
1357
1358 return dma_addr + offset;
1359fail:
1360 __free_iova(mapping, dma_addr, len);
1361 return DMA_ERROR_CODE;
1362}
1363
1364/**
1365 * arm_iommu_unmap_page
1366 * @dev: valid struct device pointer
1367 * @handle: DMA address of buffer
1368 * @size: size of buffer (same as passed to dma_map_page)
1369 * @dir: DMA transfer direction (same as passed to dma_map_page)
1370 *
1371 * IOMMU aware version of arm_dma_unmap_page()
1372 */
1373static void arm_iommu_unmap_page(struct device *dev, dma_addr_t handle,
1374 size_t size, enum dma_data_direction dir,
1375 struct dma_attrs *attrs)
1376{
1377 struct dma_iommu_mapping *mapping = dev->archdata.mapping;
1378 dma_addr_t iova = handle & PAGE_MASK;
1379 struct page *page = phys_to_page(iommu_iova_to_phys(mapping->domain, iova));
1380 int offset = handle & ~PAGE_MASK;
1381 int len = PAGE_ALIGN(size + offset);
1382
1383 if (!iova)
1384 return;
1385
1386 if (!arch_is_coherent())
1387 __dma_page_dev_to_cpu(page, offset, size, dir);
1388
1389 iommu_unmap(mapping->domain, iova, len);
1390 __free_iova(mapping, iova, len);
1391}
1392
1393static void arm_iommu_sync_single_for_cpu(struct device *dev,
1394 dma_addr_t handle, size_t size, enum dma_data_direction dir)
1395{
1396 struct dma_iommu_mapping *mapping = dev->archdata.mapping;
1397 dma_addr_t iova = handle & PAGE_MASK;
1398 struct page *page = phys_to_page(iommu_iova_to_phys(mapping->domain, iova));
1399 unsigned int offset = handle & ~PAGE_MASK;
1400
1401 if (!iova)
1402 return;
1403
1404 if (!arch_is_coherent())
1405 __dma_page_dev_to_cpu(page, offset, size, dir);
1406}
1407
1408static void arm_iommu_sync_single_for_device(struct device *dev,
1409 dma_addr_t handle, size_t size, enum dma_data_direction dir)
1410{
1411 struct dma_iommu_mapping *mapping = dev->archdata.mapping;
1412 dma_addr_t iova = handle & PAGE_MASK;
1413 struct page *page = phys_to_page(iommu_iova_to_phys(mapping->domain, iova));
1414 unsigned int offset = handle & ~PAGE_MASK;
1415
1416 if (!iova)
1417 return;
1418
1419 __dma_page_cpu_to_dev(page, offset, size, dir);
1420}
1421
1422struct dma_map_ops iommu_ops = {
1423 .alloc = arm_iommu_alloc_attrs,
1424 .free = arm_iommu_free_attrs,
1425 .mmap = arm_iommu_mmap_attrs,
1426
1427 .map_page = arm_iommu_map_page,
1428 .unmap_page = arm_iommu_unmap_page,
1429 .sync_single_for_cpu = arm_iommu_sync_single_for_cpu,
1430 .sync_single_for_device = arm_iommu_sync_single_for_device,
1431
1432 .map_sg = arm_iommu_map_sg,
1433 .unmap_sg = arm_iommu_unmap_sg,
1434 .sync_sg_for_cpu = arm_iommu_sync_sg_for_cpu,
1435 .sync_sg_for_device = arm_iommu_sync_sg_for_device,
1436};
1437
1438/**
1439 * arm_iommu_create_mapping
1440 * @bus: pointer to the bus holding the client device (for IOMMU calls)
1441 * @base: start address of the valid IO address space
1442 * @size: size of the valid IO address space
1443 * @order: accuracy of the IO addresses allocations
1444 *
1445 * Creates a mapping structure which holds information about used/unused
1446 * IO address ranges, which is required to perform memory allocation and
1447 * mapping with IOMMU aware functions.
1448 *
1449 * The client device need to be attached to the mapping with
1450 * arm_iommu_attach_device function.
1451 */
1452struct dma_iommu_mapping *
1453arm_iommu_create_mapping(struct bus_type *bus, dma_addr_t base, size_t size,
1454 int order)
1455{
1456 unsigned int count = size >> (PAGE_SHIFT + order);
1457 unsigned int bitmap_size = BITS_TO_LONGS(count) * sizeof(long);
1458 struct dma_iommu_mapping *mapping;
1459 int err = -ENOMEM;
1460
1461 if (!count)
1462 return ERR_PTR(-EINVAL);
1463
1464 mapping = kzalloc(sizeof(struct dma_iommu_mapping), GFP_KERNEL);
1465 if (!mapping)
1466 goto err;
1467
1468 mapping->bitmap = kzalloc(bitmap_size, GFP_KERNEL);
1469 if (!mapping->bitmap)
1470 goto err2;
1471
1472 mapping->base = base;
1473 mapping->bits = BITS_PER_BYTE * bitmap_size;
1474 mapping->order = order;
1475 spin_lock_init(&mapping->lock);
1476
1477 mapping->domain = iommu_domain_alloc(bus);
1478 if (!mapping->domain)
1479 goto err3;
1480
1481 kref_init(&mapping->kref);
1482 return mapping;
1483err3:
1484 kfree(mapping->bitmap);
1485err2:
1486 kfree(mapping);
1487err:
1488 return ERR_PTR(err);
1489}
1490
1491static void release_iommu_mapping(struct kref *kref)
1492{
1493 struct dma_iommu_mapping *mapping =
1494 container_of(kref, struct dma_iommu_mapping, kref);
1495
1496 iommu_domain_free(mapping->domain);
1497 kfree(mapping->bitmap);
1498 kfree(mapping);
1499}
1500
1501void arm_iommu_release_mapping(struct dma_iommu_mapping *mapping)
1502{
1503 if (mapping)
1504 kref_put(&mapping->kref, release_iommu_mapping);
1505}
1506
1507/**
1508 * arm_iommu_attach_device
1509 * @dev: valid struct device pointer
1510 * @mapping: io address space mapping structure (returned from
1511 * arm_iommu_create_mapping)
1512 *
1513 * Attaches specified io address space mapping to the provided device,
1514 * this replaces the dma operations (dma_map_ops pointer) with the
1515 * IOMMU aware version. More than one client might be attached to
1516 * the same io address space mapping.
1517 */
1518int arm_iommu_attach_device(struct device *dev,
1519 struct dma_iommu_mapping *mapping)
1520{
1521 int err;
1522
1523 err = iommu_attach_device(mapping->domain, dev);
1524 if (err)
1525 return err;
1526
1527 kref_get(&mapping->kref);
1528 dev->archdata.mapping = mapping;
1529 set_dma_ops(dev, &iommu_ops);
1530
1531 pr_info("Attached IOMMU controller to %s device.\n", dev_name(dev));
1532 return 0;
1533}
1534
1535#endif