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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>
25#include <linux/vmalloc.h>
Linus Torvalds1da177e2005-04-16 15:20:36 -070026
Lennert Buytenhek23759dc2006-04-02 00:07:39 +010027#include <asm/memory.h>
Nicolas Pitre43377452009-03-12 22:52:09 -040028#include <asm/highmem.h>
Linus Torvalds1da177e2005-04-16 15:20:36 -070029#include <asm/cacheflush.h>
Linus Torvalds1da177e2005-04-16 15:20:36 -070030#include <asm/tlbflush.h>
Kevin Hilman37134cd2006-01-12 16:12:21 +000031#include <asm/sizes.h>
Jon Medhurst99d17172011-08-02 17:28:27 +010032#include <asm/mach/arch.h>
Marek Szyprowski4ce63fc2012-05-16 15:48:21 +020033#include <asm/dma-iommu.h>
Marek Szyprowskic7909502011-12-29 13:09:51 +010034#include <asm/mach/map.h>
35#include <asm/system_info.h>
36#include <asm/dma-contiguous.h>
Linus Torvalds1da177e2005-04-16 15:20:36 -070037
Russell King022ae532011-07-08 21:26:59 +010038#include "mm.h"
39
Marek Szyprowski15237e12012-02-10 19:55:20 +010040/*
41 * The DMA API is built upon the notion of "buffer ownership". A buffer
42 * is either exclusively owned by the CPU (and therefore may be accessed
43 * by it) or exclusively owned by the DMA device. These helper functions
44 * represent the transitions between these two ownership states.
45 *
46 * Note, however, that on later ARMs, this notion does not work due to
47 * speculative prefetches. We model our approach on the assumption that
48 * the CPU does do speculative prefetches, which means we clean caches
49 * before transfers and delay cache invalidation until transfer completion.
50 *
Marek Szyprowski15237e12012-02-10 19:55:20 +010051 */
Marek Szyprowski51fde3492012-02-10 19:55:20 +010052static void __dma_page_cpu_to_dev(struct page *, unsigned long,
Marek Szyprowski15237e12012-02-10 19:55:20 +010053 size_t, enum dma_data_direction);
Marek Szyprowski51fde3492012-02-10 19:55:20 +010054static void __dma_page_dev_to_cpu(struct page *, unsigned long,
Marek Szyprowski15237e12012-02-10 19:55:20 +010055 size_t, enum dma_data_direction);
56
Marek Szyprowski2dc6a012012-02-10 19:55:20 +010057/**
58 * arm_dma_map_page - map a portion of a page for streaming DMA
59 * @dev: valid struct device pointer, or NULL for ISA and EISA-like devices
60 * @page: page that buffer resides in
61 * @offset: offset into page for start of buffer
62 * @size: size of buffer to map
63 * @dir: DMA transfer direction
64 *
65 * Ensure that any data held in the cache is appropriately discarded
66 * or written back.
67 *
68 * The device owns this memory once this call has completed. The CPU
69 * can regain ownership by calling dma_unmap_page().
70 */
Marek Szyprowski51fde3492012-02-10 19:55:20 +010071static dma_addr_t arm_dma_map_page(struct device *dev, struct page *page,
Marek Szyprowski2dc6a012012-02-10 19:55:20 +010072 unsigned long offset, size_t size, enum dma_data_direction dir,
73 struct dma_attrs *attrs)
74{
Marek Szyprowski51fde3492012-02-10 19:55:20 +010075 if (!arch_is_coherent())
76 __dma_page_cpu_to_dev(page, offset, size, dir);
77 return pfn_to_dma(dev, page_to_pfn(page)) + offset;
Marek Szyprowski2dc6a012012-02-10 19:55:20 +010078}
79
80/**
81 * arm_dma_unmap_page - unmap a buffer previously mapped through dma_map_page()
82 * @dev: valid struct device pointer, or NULL for ISA and EISA-like devices
83 * @handle: DMA address of buffer
84 * @size: size of buffer (same as passed to dma_map_page)
85 * @dir: DMA transfer direction (same as passed to dma_map_page)
86 *
87 * Unmap a page streaming mode DMA translation. The handle and size
88 * must match what was provided in the previous dma_map_page() call.
89 * All other usages are undefined.
90 *
91 * After this call, reads by the CPU to the buffer are guaranteed to see
92 * whatever the device wrote there.
93 */
Marek Szyprowski51fde3492012-02-10 19:55:20 +010094static void arm_dma_unmap_page(struct device *dev, dma_addr_t handle,
Marek Szyprowski2dc6a012012-02-10 19:55:20 +010095 size_t size, enum dma_data_direction dir,
96 struct dma_attrs *attrs)
97{
Marek Szyprowski51fde3492012-02-10 19:55:20 +010098 if (!arch_is_coherent())
99 __dma_page_dev_to_cpu(pfn_to_page(dma_to_pfn(dev, handle)),
100 handle & ~PAGE_MASK, size, dir);
Marek Szyprowski2dc6a012012-02-10 19:55:20 +0100101}
102
Marek Szyprowski51fde3492012-02-10 19:55:20 +0100103static void arm_dma_sync_single_for_cpu(struct device *dev,
Marek Szyprowski2dc6a012012-02-10 19:55:20 +0100104 dma_addr_t handle, size_t size, enum dma_data_direction dir)
105{
106 unsigned int offset = handle & (PAGE_SIZE - 1);
107 struct page *page = pfn_to_page(dma_to_pfn(dev, handle-offset));
Marek Szyprowski51fde3492012-02-10 19:55:20 +0100108 if (!arch_is_coherent())
109 __dma_page_dev_to_cpu(page, offset, size, dir);
Marek Szyprowski2dc6a012012-02-10 19:55:20 +0100110}
111
Marek Szyprowski51fde3492012-02-10 19:55:20 +0100112static void arm_dma_sync_single_for_device(struct device *dev,
Marek Szyprowski2dc6a012012-02-10 19:55:20 +0100113 dma_addr_t handle, size_t size, enum dma_data_direction dir)
114{
115 unsigned int offset = handle & (PAGE_SIZE - 1);
116 struct page *page = pfn_to_page(dma_to_pfn(dev, handle-offset));
Marek Szyprowski51fde3492012-02-10 19:55:20 +0100117 if (!arch_is_coherent())
118 __dma_page_cpu_to_dev(page, offset, size, dir);
Marek Szyprowski2dc6a012012-02-10 19:55:20 +0100119}
120
121static int arm_dma_set_mask(struct device *dev, u64 dma_mask);
122
123struct dma_map_ops arm_dma_ops = {
Marek Szyprowskif99d6032012-05-16 18:31:23 +0200124 .alloc = arm_dma_alloc,
125 .free = arm_dma_free,
126 .mmap = arm_dma_mmap,
Marek Szyprowski2dc6a012012-02-10 19:55:20 +0100127 .map_page = arm_dma_map_page,
128 .unmap_page = arm_dma_unmap_page,
129 .map_sg = arm_dma_map_sg,
130 .unmap_sg = arm_dma_unmap_sg,
131 .sync_single_for_cpu = arm_dma_sync_single_for_cpu,
132 .sync_single_for_device = arm_dma_sync_single_for_device,
133 .sync_sg_for_cpu = arm_dma_sync_sg_for_cpu,
134 .sync_sg_for_device = arm_dma_sync_sg_for_device,
135 .set_dma_mask = arm_dma_set_mask,
136};
137EXPORT_SYMBOL(arm_dma_ops);
138
Catalin Marinasab6494f2009-07-24 12:35:02 +0100139static u64 get_coherent_dma_mask(struct device *dev)
140{
Russell King022ae532011-07-08 21:26:59 +0100141 u64 mask = (u64)arm_dma_limit;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700142
Catalin Marinasab6494f2009-07-24 12:35:02 +0100143 if (dev) {
144 mask = dev->coherent_dma_mask;
145
146 /*
147 * Sanity check the DMA mask - it must be non-zero, and
148 * must be able to be satisfied by a DMA allocation.
149 */
150 if (mask == 0) {
151 dev_warn(dev, "coherent DMA mask is unset\n");
152 return 0;
153 }
154
Russell King022ae532011-07-08 21:26:59 +0100155 if ((~mask) & (u64)arm_dma_limit) {
Catalin Marinasab6494f2009-07-24 12:35:02 +0100156 dev_warn(dev, "coherent DMA mask %#llx is smaller "
157 "than system GFP_DMA mask %#llx\n",
Russell King022ae532011-07-08 21:26:59 +0100158 mask, (u64)arm_dma_limit);
Catalin Marinasab6494f2009-07-24 12:35:02 +0100159 return 0;
160 }
161 }
162
163 return mask;
164}
165
Marek Szyprowskic7909502011-12-29 13:09:51 +0100166static void __dma_clear_buffer(struct page *page, size_t size)
167{
168 void *ptr;
169 /*
170 * Ensure that the allocated pages are zeroed, and that any data
171 * lurking in the kernel direct-mapped region is invalidated.
172 */
173 ptr = page_address(page);
Marek Szyprowski4ce63fc2012-05-16 15:48:21 +0200174 if (ptr) {
175 memset(ptr, 0, size);
176 dmac_flush_range(ptr, ptr + size);
177 outer_flush_range(__pa(ptr), __pa(ptr) + size);
178 }
Marek Szyprowskic7909502011-12-29 13:09:51 +0100179}
180
Russell King7a9a32a2009-11-19 15:31:07 +0000181/*
182 * Allocate a DMA buffer for 'dev' of size 'size' using the
183 * specified gfp mask. Note that 'size' must be page aligned.
184 */
185static struct page *__dma_alloc_buffer(struct device *dev, size_t size, gfp_t gfp)
186{
187 unsigned long order = get_order(size);
188 struct page *page, *p, *e;
Russell King7a9a32a2009-11-19 15:31:07 +0000189
190 page = alloc_pages(gfp, order);
191 if (!page)
192 return NULL;
193
194 /*
195 * Now split the huge page and free the excess pages
196 */
197 split_page(page, order);
198 for (p = page + (size >> PAGE_SHIFT), e = page + (1 << order); p < e; p++)
199 __free_page(p);
200
Marek Szyprowskic7909502011-12-29 13:09:51 +0100201 __dma_clear_buffer(page, size);
Russell King7a9a32a2009-11-19 15:31:07 +0000202
203 return page;
204}
205
206/*
207 * Free a DMA buffer. 'size' must be page aligned.
208 */
209static void __dma_free_buffer(struct page *page, size_t size)
210{
211 struct page *e = page + (size >> PAGE_SHIFT);
212
213 while (page < e) {
214 __free_page(page);
215 page++;
216 }
217}
218
Catalin Marinasab6494f2009-07-24 12:35:02 +0100219#ifdef CONFIG_MMU
Catalin Marinasa5e9d382010-06-21 15:09:06 +0100220
Jon Medhurst99d17172011-08-02 17:28:27 +0100221#define CONSISTENT_OFFSET(x) (((unsigned long)(x) - consistent_base) >> PAGE_SHIFT)
Linus Torvalds1fdb24e2011-10-28 12:02:27 -0700222#define CONSISTENT_PTE_INDEX(x) (((unsigned long)(x) - consistent_base) >> PMD_SHIFT)
Catalin Marinasa5e9d382010-06-21 15:09:06 +0100223
Linus Torvalds1da177e2005-04-16 15:20:36 -0700224/*
Kevin Hilman37134cd2006-01-12 16:12:21 +0000225 * These are the page tables (2MB each) covering uncached, DMA consistent allocations
Linus Torvalds1da177e2005-04-16 15:20:36 -0700226 */
Jon Medhurst99d17172011-08-02 17:28:27 +0100227static pte_t **consistent_pte;
228
Jon Medhurst99d17172011-08-02 17:28:27 +0100229#define DEFAULT_CONSISTENT_DMA_SIZE SZ_2M
Jon Medhurst99d17172011-08-02 17:28:27 +0100230
Sachin Kamate53f5172012-06-06 08:03:35 +0200231static unsigned long consistent_base = CONSISTENT_END - DEFAULT_CONSISTENT_DMA_SIZE;
Jon Medhurst99d17172011-08-02 17:28:27 +0100232
233void __init init_consistent_dma_size(unsigned long size)
234{
235 unsigned long base = CONSISTENT_END - ALIGN(size, SZ_2M);
236
237 BUG_ON(consistent_pte); /* Check we're called before DMA region init */
238 BUG_ON(base < VMALLOC_END);
239
240 /* Grow region to accommodate specified size */
241 if (base < consistent_base)
242 consistent_base = base;
243}
Linus Torvalds1da177e2005-04-16 15:20:36 -0700244
Russell King13ccf3a2009-11-19 15:07:04 +0000245#include "vmregion.h"
Linus Torvalds1da177e2005-04-16 15:20:36 -0700246
Russell King13ccf3a2009-11-19 15:07:04 +0000247static struct arm_vmregion_head consistent_head = {
248 .vm_lock = __SPIN_LOCK_UNLOCKED(&consistent_head.vm_lock),
Linus Torvalds1da177e2005-04-16 15:20:36 -0700249 .vm_list = LIST_HEAD_INIT(consistent_head.vm_list),
Linus Torvalds1da177e2005-04-16 15:20:36 -0700250 .vm_end = CONSISTENT_END,
251};
252
Linus Torvalds1da177e2005-04-16 15:20:36 -0700253#ifdef CONFIG_HUGETLB_PAGE
254#error ARM Coherent DMA allocator does not (yet) support huge TLB
255#endif
256
Russell King88c58f32009-11-19 16:46:02 +0000257/*
258 * Initialise the consistent memory allocation.
259 */
260static int __init consistent_init(void)
261{
262 int ret = 0;
263 pgd_t *pgd;
Russell King516295e2010-11-21 16:27:49 +0000264 pud_t *pud;
Russell King88c58f32009-11-19 16:46:02 +0000265 pmd_t *pmd;
266 pte_t *pte;
267 int i = 0;
Jon Medhurst99d17172011-08-02 17:28:27 +0100268 unsigned long base = consistent_base;
Catalin Marinas53cbcbc2011-11-17 13:11:21 +0100269 unsigned long num_ptes = (CONSISTENT_END - base) >> PMD_SHIFT;
Jon Medhurst99d17172011-08-02 17:28:27 +0100270
Marek Szyprowskif1ae98d2012-05-30 10:48:29 +0200271 if (IS_ENABLED(CONFIG_CMA) && !IS_ENABLED(CONFIG_ARM_DMA_USE_IOMMU))
Marek Szyprowskic7909502011-12-29 13:09:51 +0100272 return 0;
273
Jon Medhurst99d17172011-08-02 17:28:27 +0100274 consistent_pte = kmalloc(num_ptes * sizeof(pte_t), GFP_KERNEL);
275 if (!consistent_pte) {
276 pr_err("%s: no memory\n", __func__);
277 return -ENOMEM;
278 }
279
280 pr_debug("DMA memory: 0x%08lx - 0x%08lx:\n", base, CONSISTENT_END);
281 consistent_head.vm_start = base;
Russell King88c58f32009-11-19 16:46:02 +0000282
283 do {
284 pgd = pgd_offset(&init_mm, base);
Russell King516295e2010-11-21 16:27:49 +0000285
286 pud = pud_alloc(&init_mm, pgd, base);
287 if (!pud) {
Marek Szyprowski6b6f7702012-02-28 10:19:14 +0100288 pr_err("%s: no pud tables\n", __func__);
Russell King516295e2010-11-21 16:27:49 +0000289 ret = -ENOMEM;
290 break;
291 }
292
293 pmd = pmd_alloc(&init_mm, pud, base);
Russell King88c58f32009-11-19 16:46:02 +0000294 if (!pmd) {
Marek Szyprowski6b6f7702012-02-28 10:19:14 +0100295 pr_err("%s: no pmd tables\n", __func__);
Russell King88c58f32009-11-19 16:46:02 +0000296 ret = -ENOMEM;
297 break;
298 }
299 WARN_ON(!pmd_none(*pmd));
300
301 pte = pte_alloc_kernel(pmd, base);
302 if (!pte) {
Marek Szyprowski6b6f7702012-02-28 10:19:14 +0100303 pr_err("%s: no pte tables\n", __func__);
Russell King88c58f32009-11-19 16:46:02 +0000304 ret = -ENOMEM;
305 break;
306 }
307
308 consistent_pte[i++] = pte;
Catalin Marinase73fc882011-08-23 14:07:23 +0100309 base += PMD_SIZE;
Russell King88c58f32009-11-19 16:46:02 +0000310 } while (base < CONSISTENT_END);
311
312 return ret;
313}
Russell King88c58f32009-11-19 16:46:02 +0000314core_initcall(consistent_init);
315
Marek Szyprowskic7909502011-12-29 13:09:51 +0100316static void *__alloc_from_contiguous(struct device *dev, size_t size,
317 pgprot_t prot, struct page **ret_page);
318
319static struct arm_vmregion_head coherent_head = {
320 .vm_lock = __SPIN_LOCK_UNLOCKED(&coherent_head.vm_lock),
321 .vm_list = LIST_HEAD_INIT(coherent_head.vm_list),
322};
323
Sachin Kamate53f5172012-06-06 08:03:35 +0200324static size_t coherent_pool_size = DEFAULT_CONSISTENT_DMA_SIZE / 8;
Marek Szyprowskic7909502011-12-29 13:09:51 +0100325
326static int __init early_coherent_pool(char *p)
327{
328 coherent_pool_size = memparse(p, &p);
329 return 0;
330}
331early_param("coherent_pool", early_coherent_pool);
332
333/*
334 * Initialise the coherent pool for atomic allocations.
335 */
336static int __init coherent_init(void)
337{
338 pgprot_t prot = pgprot_dmacoherent(pgprot_kernel);
339 size_t size = coherent_pool_size;
340 struct page *page;
341 void *ptr;
342
Marek Szyprowskif1ae98d2012-05-30 10:48:29 +0200343 if (!IS_ENABLED(CONFIG_CMA))
Marek Szyprowskic7909502011-12-29 13:09:51 +0100344 return 0;
345
346 ptr = __alloc_from_contiguous(NULL, size, prot, &page);
347 if (ptr) {
348 coherent_head.vm_start = (unsigned long) ptr;
349 coherent_head.vm_end = (unsigned long) ptr + size;
350 printk(KERN_INFO "DMA: preallocated %u KiB pool for atomic coherent allocations\n",
351 (unsigned)size / 1024);
352 return 0;
353 }
354 printk(KERN_ERR "DMA: failed to allocate %u KiB pool for atomic coherent allocation\n",
355 (unsigned)size / 1024);
356 return -ENOMEM;
357}
358/*
359 * CMA is activated by core_initcall, so we must be called after it.
360 */
361postcore_initcall(coherent_init);
362
363struct dma_contig_early_reserve {
364 phys_addr_t base;
365 unsigned long size;
366};
367
368static struct dma_contig_early_reserve dma_mmu_remap[MAX_CMA_AREAS] __initdata;
369
370static int dma_mmu_remap_num __initdata;
371
372void __init dma_contiguous_early_fixup(phys_addr_t base, unsigned long size)
373{
374 dma_mmu_remap[dma_mmu_remap_num].base = base;
375 dma_mmu_remap[dma_mmu_remap_num].size = size;
376 dma_mmu_remap_num++;
377}
378
379void __init dma_contiguous_remap(void)
380{
381 int i;
382 for (i = 0; i < dma_mmu_remap_num; i++) {
383 phys_addr_t start = dma_mmu_remap[i].base;
384 phys_addr_t end = start + dma_mmu_remap[i].size;
385 struct map_desc map;
386 unsigned long addr;
387
388 if (end > arm_lowmem_limit)
389 end = arm_lowmem_limit;
390 if (start >= end)
391 return;
392
393 map.pfn = __phys_to_pfn(start);
394 map.virtual = __phys_to_virt(start);
395 map.length = end - start;
396 map.type = MT_MEMORY_DMA_READY;
397
398 /*
399 * Clear previous low-memory mapping
400 */
401 for (addr = __phys_to_virt(start); addr < __phys_to_virt(end);
Vitaly Andrianov61f6c7a2012-05-14 13:49:56 -0400402 addr += PMD_SIZE)
Marek Szyprowskic7909502011-12-29 13:09:51 +0100403 pmd_clear(pmd_off_k(addr));
404
405 iotable_init(&map, 1);
406 }
407}
408
Linus Torvalds1da177e2005-04-16 15:20:36 -0700409static void *
Russell King45cd5292012-01-12 23:08:07 +0000410__dma_alloc_remap(struct page *page, size_t size, gfp_t gfp, pgprot_t prot,
411 const void *caller)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700412{
Russell King13ccf3a2009-11-19 15:07:04 +0000413 struct arm_vmregion *c;
Russell King5bc23d32010-07-25 08:57:02 +0100414 size_t align;
415 int bit;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700416
Jon Medhurst99d17172011-08-02 17:28:27 +0100417 if (!consistent_pte) {
Marek Szyprowski6b6f7702012-02-28 10:19:14 +0100418 pr_err("%s: not initialised\n", __func__);
Russell Kingebd7a842009-11-19 20:58:31 +0000419 dump_stack();
Russell Kingebd7a842009-11-19 20:58:31 +0000420 return NULL;
421 }
422
Linus Torvalds1da177e2005-04-16 15:20:36 -0700423 /*
Russell King5bc23d32010-07-25 08:57:02 +0100424 * Align the virtual region allocation - maximum alignment is
425 * a section size, minimum is a page size. This helps reduce
426 * fragmentation of the DMA space, and also prevents allocations
427 * smaller than a section from crossing a section boundary.
428 */
Russell Kingc947f692010-11-03 16:00:15 +0000429 bit = fls(size - 1);
Russell King5bc23d32010-07-25 08:57:02 +0100430 if (bit > SECTION_SHIFT)
431 bit = SECTION_SHIFT;
432 align = 1 << bit;
433
434 /*
Linus Torvalds1da177e2005-04-16 15:20:36 -0700435 * Allocate a virtual address in the consistent mapping region.
436 */
Russell King5bc23d32010-07-25 08:57:02 +0100437 c = arm_vmregion_alloc(&consistent_head, align, size,
Russell King45cd5292012-01-12 23:08:07 +0000438 gfp & ~(__GFP_DMA | __GFP_HIGHMEM), caller);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700439 if (c) {
Kevin Hilman37134cd2006-01-12 16:12:21 +0000440 pte_t *pte;
Kevin Hilman37134cd2006-01-12 16:12:21 +0000441 int idx = CONSISTENT_PTE_INDEX(c->vm_start);
442 u32 off = CONSISTENT_OFFSET(c->vm_start) & (PTRS_PER_PTE-1);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700443
Kevin Hilman37134cd2006-01-12 16:12:21 +0000444 pte = consistent_pte[idx] + off;
Marek Szyprowski4ce63fc2012-05-16 15:48:21 +0200445 c->priv = page;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700446
Linus Torvalds1da177e2005-04-16 15:20:36 -0700447 do {
448 BUG_ON(!pte_none(*pte));
449
Russell Kingad1ae2f2006-12-13 14:34:43 +0000450 set_pte_ext(pte, mk_pte(page, prot), 0);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700451 page++;
452 pte++;
Kevin Hilman37134cd2006-01-12 16:12:21 +0000453 off++;
454 if (off >= PTRS_PER_PTE) {
455 off = 0;
456 pte = consistent_pte[++idx];
457 }
Linus Torvalds1da177e2005-04-16 15:20:36 -0700458 } while (size -= PAGE_SIZE);
459
Russell King2be23c42010-09-08 16:27:56 +0100460 dsb();
461
Linus Torvalds1da177e2005-04-16 15:20:36 -0700462 return (void *)c->vm_start;
463 }
Linus Torvalds1da177e2005-04-16 15:20:36 -0700464 return NULL;
465}
Russell King695ae0a2009-11-19 16:31:39 +0000466
467static void __dma_free_remap(void *cpu_addr, size_t size)
468{
469 struct arm_vmregion *c;
470 unsigned long addr;
471 pte_t *ptep;
472 int idx;
473 u32 off;
474
475 c = arm_vmregion_find_remove(&consistent_head, (unsigned long)cpu_addr);
476 if (!c) {
Marek Szyprowski6b6f7702012-02-28 10:19:14 +0100477 pr_err("%s: trying to free invalid coherent area: %p\n",
Russell King695ae0a2009-11-19 16:31:39 +0000478 __func__, cpu_addr);
479 dump_stack();
480 return;
481 }
482
483 if ((c->vm_end - c->vm_start) != size) {
Marek Szyprowski6b6f7702012-02-28 10:19:14 +0100484 pr_err("%s: freeing wrong coherent size (%ld != %d)\n",
Russell King695ae0a2009-11-19 16:31:39 +0000485 __func__, c->vm_end - c->vm_start, size);
486 dump_stack();
487 size = c->vm_end - c->vm_start;
488 }
489
490 idx = CONSISTENT_PTE_INDEX(c->vm_start);
491 off = CONSISTENT_OFFSET(c->vm_start) & (PTRS_PER_PTE-1);
492 ptep = consistent_pte[idx] + off;
493 addr = c->vm_start;
494 do {
495 pte_t pte = ptep_get_and_clear(&init_mm, addr, ptep);
Russell King695ae0a2009-11-19 16:31:39 +0000496
497 ptep++;
498 addr += PAGE_SIZE;
499 off++;
500 if (off >= PTRS_PER_PTE) {
501 off = 0;
502 ptep = consistent_pte[++idx];
503 }
504
Russell Kingacaac252009-11-20 18:19:52 +0000505 if (pte_none(pte) || !pte_present(pte))
Marek Szyprowski6b6f7702012-02-28 10:19:14 +0100506 pr_crit("%s: bad page in kernel page table\n",
507 __func__);
Russell King695ae0a2009-11-19 16:31:39 +0000508 } while (size -= PAGE_SIZE);
509
510 flush_tlb_kernel_range(c->vm_start, c->vm_end);
511
512 arm_vmregion_free(&consistent_head, c);
513}
514
Marek Szyprowskic7909502011-12-29 13:09:51 +0100515static int __dma_update_pte(pte_t *pte, pgtable_t token, unsigned long addr,
516 void *data)
517{
518 struct page *page = virt_to_page(addr);
519 pgprot_t prot = *(pgprot_t *)data;
520
521 set_pte_ext(pte, mk_pte(page, prot), 0);
522 return 0;
523}
524
525static void __dma_remap(struct page *page, size_t size, pgprot_t prot)
526{
527 unsigned long start = (unsigned long) page_address(page);
528 unsigned end = start + size;
529
530 apply_to_page_range(&init_mm, start, size, __dma_update_pte, &prot);
531 dsb();
532 flush_tlb_kernel_range(start, end);
533}
534
535static void *__alloc_remap_buffer(struct device *dev, size_t size, gfp_t gfp,
536 pgprot_t prot, struct page **ret_page,
537 const void *caller)
538{
539 struct page *page;
540 void *ptr;
541 page = __dma_alloc_buffer(dev, size, gfp);
542 if (!page)
543 return NULL;
544
545 ptr = __dma_alloc_remap(page, size, gfp, prot, caller);
546 if (!ptr) {
547 __dma_free_buffer(page, size);
548 return NULL;
549 }
550
551 *ret_page = page;
552 return ptr;
553}
554
555static void *__alloc_from_pool(struct device *dev, size_t size,
556 struct page **ret_page, const void *caller)
557{
558 struct arm_vmregion *c;
559 size_t align;
560
561 if (!coherent_head.vm_start) {
562 printk(KERN_ERR "%s: coherent pool not initialised!\n",
563 __func__);
564 dump_stack();
565 return NULL;
566 }
567
568 /*
569 * Align the region allocation - allocations from pool are rather
570 * small, so align them to their order in pages, minimum is a page
571 * size. This helps reduce fragmentation of the DMA space.
572 */
573 align = PAGE_SIZE << get_order(size);
574 c = arm_vmregion_alloc(&coherent_head, align, size, 0, caller);
575 if (c) {
576 void *ptr = (void *)c->vm_start;
577 struct page *page = virt_to_page(ptr);
578 *ret_page = page;
579 return ptr;
580 }
581 return NULL;
582}
583
584static int __free_from_pool(void *cpu_addr, size_t size)
585{
586 unsigned long start = (unsigned long)cpu_addr;
587 unsigned long end = start + size;
588 struct arm_vmregion *c;
589
590 if (start < coherent_head.vm_start || end > coherent_head.vm_end)
591 return 0;
592
593 c = arm_vmregion_find_remove(&coherent_head, (unsigned long)start);
594
595 if ((c->vm_end - c->vm_start) != size) {
596 printk(KERN_ERR "%s: freeing wrong coherent size (%ld != %d)\n",
597 __func__, c->vm_end - c->vm_start, size);
598 dump_stack();
599 size = c->vm_end - c->vm_start;
600 }
601
602 arm_vmregion_free(&coherent_head, c);
603 return 1;
604}
605
606static void *__alloc_from_contiguous(struct device *dev, size_t size,
607 pgprot_t prot, struct page **ret_page)
608{
609 unsigned long order = get_order(size);
610 size_t count = size >> PAGE_SHIFT;
611 struct page *page;
612
613 page = dma_alloc_from_contiguous(dev, count, order);
614 if (!page)
615 return NULL;
616
617 __dma_clear_buffer(page, size);
618 __dma_remap(page, size, prot);
619
620 *ret_page = page;
621 return page_address(page);
622}
623
624static void __free_from_contiguous(struct device *dev, struct page *page,
625 size_t size)
626{
627 __dma_remap(page, size, pgprot_kernel);
628 dma_release_from_contiguous(dev, page, size >> PAGE_SHIFT);
629}
630
Marek Szyprowskif99d6032012-05-16 18:31:23 +0200631static inline pgprot_t __get_dma_pgprot(struct dma_attrs *attrs, pgprot_t prot)
632{
633 prot = dma_get_attr(DMA_ATTR_WRITE_COMBINE, attrs) ?
634 pgprot_writecombine(prot) :
635 pgprot_dmacoherent(prot);
636 return prot;
637}
638
Marek Szyprowskic7909502011-12-29 13:09:51 +0100639#define nommu() 0
640
Catalin Marinasab6494f2009-07-24 12:35:02 +0100641#else /* !CONFIG_MMU */
Russell King695ae0a2009-11-19 16:31:39 +0000642
Marek Szyprowskic7909502011-12-29 13:09:51 +0100643#define nommu() 1
644
Marek Szyprowskif99d6032012-05-16 18:31:23 +0200645#define __get_dma_pgprot(attrs, prot) __pgprot(0)
Marek Szyprowskic7909502011-12-29 13:09:51 +0100646#define __alloc_remap_buffer(dev, size, gfp, prot, ret, c) NULL
647#define __alloc_from_pool(dev, size, ret_page, c) NULL
648#define __alloc_from_contiguous(dev, size, prot, ret) NULL
649#define __free_from_pool(cpu_addr, size) 0
650#define __free_from_contiguous(dev, page, size) do { } while (0)
651#define __dma_free_remap(cpu_addr, size) do { } while (0)
Russell King31ebf942009-11-19 21:12:17 +0000652
653#endif /* CONFIG_MMU */
654
Marek Szyprowskic7909502011-12-29 13:09:51 +0100655static void *__alloc_simple_buffer(struct device *dev, size_t size, gfp_t gfp,
656 struct page **ret_page)
Catalin Marinasab6494f2009-07-24 12:35:02 +0100657{
Russell King04da5692009-11-19 15:54:45 +0000658 struct page *page;
Marek Szyprowskic7909502011-12-29 13:09:51 +0100659 page = __dma_alloc_buffer(dev, size, gfp);
660 if (!page)
661 return NULL;
662
663 *ret_page = page;
664 return page_address(page);
665}
666
667
668
669static void *__dma_alloc(struct device *dev, size_t size, dma_addr_t *handle,
670 gfp_t gfp, pgprot_t prot, const void *caller)
671{
672 u64 mask = get_coherent_dma_mask(dev);
673 struct page *page;
Russell King31ebf942009-11-19 21:12:17 +0000674 void *addr;
Catalin Marinasab6494f2009-07-24 12:35:02 +0100675
Marek Szyprowskic7909502011-12-29 13:09:51 +0100676#ifdef CONFIG_DMA_API_DEBUG
677 u64 limit = (mask + 1) & ~mask;
678 if (limit && size >= limit) {
679 dev_warn(dev, "coherent allocation too big (requested %#x mask %#llx)\n",
680 size, mask);
681 return NULL;
682 }
683#endif
684
685 if (!mask)
686 return NULL;
687
688 if (mask < 0xffffffffULL)
689 gfp |= GFP_DMA;
690
Sumit Bhattacharyaea2e7052011-11-24 00:47:12 +0100691 /*
692 * Following is a work-around (a.k.a. hack) to prevent pages
693 * with __GFP_COMP being passed to split_page() which cannot
694 * handle them. The real problem is that this flag probably
695 * should be 0 on ARM as it is not supported on this
696 * platform; see CONFIG_HUGETLBFS.
697 */
698 gfp &= ~(__GFP_COMP);
699
Marek Szyprowski553ac782012-02-29 14:45:28 +0100700 *handle = DMA_ERROR_CODE;
Russell King04da5692009-11-19 15:54:45 +0000701 size = PAGE_ALIGN(size);
702
Marek Szyprowskic7909502011-12-29 13:09:51 +0100703 if (arch_is_coherent() || nommu())
704 addr = __alloc_simple_buffer(dev, size, gfp, &page);
Marek Szyprowskif1ae98d2012-05-30 10:48:29 +0200705 else if (!IS_ENABLED(CONFIG_CMA))
Marek Szyprowskic7909502011-12-29 13:09:51 +0100706 addr = __alloc_remap_buffer(dev, size, gfp, prot, &page, caller);
707 else if (gfp & GFP_ATOMIC)
708 addr = __alloc_from_pool(dev, size, &page, caller);
Russell King31ebf942009-11-19 21:12:17 +0000709 else
Marek Szyprowskic7909502011-12-29 13:09:51 +0100710 addr = __alloc_from_contiguous(dev, size, prot, &page);
Russell King31ebf942009-11-19 21:12:17 +0000711
712 if (addr)
Russell King9eedd962011-01-03 00:00:17 +0000713 *handle = pfn_to_dma(dev, page_to_pfn(page));
Russell King31ebf942009-11-19 21:12:17 +0000714
715 return addr;
Catalin Marinasab6494f2009-07-24 12:35:02 +0100716}
Russell King695ae0a2009-11-19 16:31:39 +0000717
Linus Torvalds1da177e2005-04-16 15:20:36 -0700718/*
719 * Allocate DMA-coherent memory space and return both the kernel remapped
720 * virtual and bus address for that space.
721 */
Marek Szyprowskif99d6032012-05-16 18:31:23 +0200722void *arm_dma_alloc(struct device *dev, size_t size, dma_addr_t *handle,
723 gfp_t gfp, struct dma_attrs *attrs)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700724{
Marek Szyprowskif99d6032012-05-16 18:31:23 +0200725 pgprot_t prot = __get_dma_pgprot(attrs, pgprot_kernel);
Dmitry Baryshkov1fe53262008-07-18 13:30:14 +0400726 void *memory;
727
728 if (dma_alloc_from_coherent(dev, size, handle, &memory))
729 return memory;
730
Marek Szyprowskif99d6032012-05-16 18:31:23 +0200731 return __dma_alloc(dev, size, handle, gfp, prot,
Russell King45cd5292012-01-12 23:08:07 +0000732 __builtin_return_address(0));
Linus Torvalds1da177e2005-04-16 15:20:36 -0700733}
Linus Torvalds1da177e2005-04-16 15:20:36 -0700734
735/*
Marek Szyprowskif99d6032012-05-16 18:31:23 +0200736 * Create userspace mapping for the DMA-coherent memory.
Linus Torvalds1da177e2005-04-16 15:20:36 -0700737 */
Marek Szyprowskif99d6032012-05-16 18:31:23 +0200738int arm_dma_mmap(struct device *dev, struct vm_area_struct *vma,
739 void *cpu_addr, dma_addr_t dma_addr, size_t size,
740 struct dma_attrs *attrs)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700741{
Catalin Marinasab6494f2009-07-24 12:35:02 +0100742 int ret = -ENXIO;
743#ifdef CONFIG_MMU
Marek Szyprowskic7909502011-12-29 13:09:51 +0100744 unsigned long pfn = dma_to_pfn(dev, dma_addr);
Marek Szyprowskif99d6032012-05-16 18:31:23 +0200745 vma->vm_page_prot = __get_dma_pgprot(attrs, vma->vm_page_prot);
746
Marek Szyprowski47142f02012-05-15 19:04:13 +0200747 if (dma_mmap_from_coherent(dev, vma, cpu_addr, size, &ret))
748 return ret;
749
Marek Szyprowskic7909502011-12-29 13:09:51 +0100750 ret = remap_pfn_range(vma, vma->vm_start,
751 pfn + vma->vm_pgoff,
752 vma->vm_end - vma->vm_start,
753 vma->vm_page_prot);
Catalin Marinasab6494f2009-07-24 12:35:02 +0100754#endif /* CONFIG_MMU */
Linus Torvalds1da177e2005-04-16 15:20:36 -0700755
756 return ret;
757}
758
Linus Torvalds1da177e2005-04-16 15:20:36 -0700759/*
Marek Szyprowskic7909502011-12-29 13:09:51 +0100760 * Free a buffer as defined by the above mapping.
Linus Torvalds1da177e2005-04-16 15:20:36 -0700761 */
Marek Szyprowskif99d6032012-05-16 18:31:23 +0200762void arm_dma_free(struct device *dev, size_t size, void *cpu_addr,
763 dma_addr_t handle, struct dma_attrs *attrs)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700764{
Marek Szyprowskic7909502011-12-29 13:09:51 +0100765 struct page *page = pfn_to_page(dma_to_pfn(dev, handle));
Russell King5edf71a2005-11-25 15:52:51 +0000766
Dmitry Baryshkov1fe53262008-07-18 13:30:14 +0400767 if (dma_release_from_coherent(dev, get_order(size), cpu_addr))
768 return;
769
Russell King3e82d012009-11-19 15:38:12 +0000770 size = PAGE_ALIGN(size);
771
Marek Szyprowskic7909502011-12-29 13:09:51 +0100772 if (arch_is_coherent() || nommu()) {
773 __dma_free_buffer(page, size);
Marek Szyprowskif1ae98d2012-05-30 10:48:29 +0200774 } else if (!IS_ENABLED(CONFIG_CMA)) {
Russell King695ae0a2009-11-19 16:31:39 +0000775 __dma_free_remap(cpu_addr, size);
Marek Szyprowskic7909502011-12-29 13:09:51 +0100776 __dma_free_buffer(page, size);
777 } else {
778 if (__free_from_pool(cpu_addr, size))
779 return;
780 /*
781 * Non-atomic allocations cannot be freed with IRQs disabled
782 */
783 WARN_ON(irqs_disabled());
784 __free_from_contiguous(dev, page, size);
785 }
Linus Torvalds1da177e2005-04-16 15:20:36 -0700786}
Russell Kingafd1a322008-09-25 16:30:57 +0100787
Russell King65af1912009-11-24 17:53:33 +0000788static void dma_cache_maint_page(struct page *page, unsigned long offset,
Russell Kinga9c91472009-11-26 16:19:58 +0000789 size_t size, enum dma_data_direction dir,
790 void (*op)(const void *, size_t, int))
Russell King65af1912009-11-24 17:53:33 +0000791{
792 /*
793 * A single sg entry may refer to multiple physically contiguous
794 * pages. But we still need to process highmem pages individually.
795 * If highmem is not configured then the bulk of this loop gets
796 * optimized out.
797 */
798 size_t left = size;
799 do {
800 size_t len = left;
Russell King93f1d622009-11-24 14:41:01 +0000801 void *vaddr;
802
803 if (PageHighMem(page)) {
804 if (len + offset > PAGE_SIZE) {
805 if (offset >= PAGE_SIZE) {
806 page += offset / PAGE_SIZE;
807 offset %= PAGE_SIZE;
808 }
809 len = PAGE_SIZE - offset;
Russell King65af1912009-11-24 17:53:33 +0000810 }
Russell King93f1d622009-11-24 14:41:01 +0000811 vaddr = kmap_high_get(page);
812 if (vaddr) {
813 vaddr += offset;
Russell Kinga9c91472009-11-26 16:19:58 +0000814 op(vaddr, len, dir);
Russell King93f1d622009-11-24 14:41:01 +0000815 kunmap_high(page);
Nicolas Pitre7e5a69e2010-03-29 21:46:02 +0100816 } else if (cache_is_vipt()) {
Nicolas Pitre39af22a2010-12-15 15:14:45 -0500817 /* unmapped pages might still be cached */
818 vaddr = kmap_atomic(page);
Nicolas Pitre7e5a69e2010-03-29 21:46:02 +0100819 op(vaddr + offset, len, dir);
Nicolas Pitre39af22a2010-12-15 15:14:45 -0500820 kunmap_atomic(vaddr);
Russell King93f1d622009-11-24 14:41:01 +0000821 }
822 } else {
823 vaddr = page_address(page) + offset;
Russell Kinga9c91472009-11-26 16:19:58 +0000824 op(vaddr, len, dir);
Russell King65af1912009-11-24 17:53:33 +0000825 }
Russell King65af1912009-11-24 17:53:33 +0000826 offset = 0;
827 page++;
828 left -= len;
829 } while (left);
830}
831
Marek Szyprowski51fde3492012-02-10 19:55:20 +0100832/*
833 * Make an area consistent for devices.
834 * Note: Drivers should NOT use this function directly, as it will break
835 * platforms with CONFIG_DMABOUNCE.
836 * Use the driver DMA support - see dma-mapping.h (dma_sync_*)
837 */
838static void __dma_page_cpu_to_dev(struct page *page, unsigned long off,
Russell King65af1912009-11-24 17:53:33 +0000839 size_t size, enum dma_data_direction dir)
840{
Nicolas Pitre43377452009-03-12 22:52:09 -0400841 unsigned long paddr;
Nicolas Pitre43377452009-03-12 22:52:09 -0400842
Russell Kinga9c91472009-11-26 16:19:58 +0000843 dma_cache_maint_page(page, off, size, dir, dmac_map_area);
Nicolas Pitre43377452009-03-12 22:52:09 -0400844
Russell King65af1912009-11-24 17:53:33 +0000845 paddr = page_to_phys(page) + off;
Russell King2ffe2da2009-10-31 16:52:16 +0000846 if (dir == DMA_FROM_DEVICE) {
847 outer_inv_range(paddr, paddr + size);
848 } else {
849 outer_clean_range(paddr, paddr + size);
850 }
851 /* FIXME: non-speculating: flush on bidirectional mappings? */
Nicolas Pitre43377452009-03-12 22:52:09 -0400852}
Russell King4ea0d732009-11-24 16:27:17 +0000853
Marek Szyprowski51fde3492012-02-10 19:55:20 +0100854static void __dma_page_dev_to_cpu(struct page *page, unsigned long off,
Russell King4ea0d732009-11-24 16:27:17 +0000855 size_t size, enum dma_data_direction dir)
856{
Russell King2ffe2da2009-10-31 16:52:16 +0000857 unsigned long paddr = page_to_phys(page) + off;
858
859 /* FIXME: non-speculating: not required */
860 /* don't bother invalidating if DMA to device */
861 if (dir != DMA_TO_DEVICE)
862 outer_inv_range(paddr, paddr + size);
863
Russell Kinga9c91472009-11-26 16:19:58 +0000864 dma_cache_maint_page(page, off, size, dir, dmac_unmap_area);
Catalin Marinasc0177802010-09-13 15:57:36 +0100865
866 /*
867 * Mark the D-cache clean for this page to avoid extra flushing.
868 */
869 if (dir != DMA_TO_DEVICE && off == 0 && size >= PAGE_SIZE)
870 set_bit(PG_dcache_clean, &page->flags);
Russell King4ea0d732009-11-24 16:27:17 +0000871}
Nicolas Pitre43377452009-03-12 22:52:09 -0400872
Russell Kingafd1a322008-09-25 16:30:57 +0100873/**
Marek Szyprowski2a550e72012-02-10 19:55:20 +0100874 * arm_dma_map_sg - map a set of SG buffers for streaming mode DMA
Russell Kingafd1a322008-09-25 16:30:57 +0100875 * @dev: valid struct device pointer, or NULL for ISA and EISA-like devices
876 * @sg: list of buffers
877 * @nents: number of buffers to map
878 * @dir: DMA transfer direction
879 *
880 * Map a set of buffers described by scatterlist in streaming mode for DMA.
881 * This is the scatter-gather version of the dma_map_single interface.
882 * Here the scatter gather list elements are each tagged with the
883 * appropriate dma address and length. They are obtained via
884 * sg_dma_{address,length}.
885 *
886 * Device ownership issues as mentioned for dma_map_single are the same
887 * here.
888 */
Marek Szyprowski2dc6a012012-02-10 19:55:20 +0100889int arm_dma_map_sg(struct device *dev, struct scatterlist *sg, int nents,
890 enum dma_data_direction dir, struct dma_attrs *attrs)
Russell Kingafd1a322008-09-25 16:30:57 +0100891{
Marek Szyprowski2a550e72012-02-10 19:55:20 +0100892 struct dma_map_ops *ops = get_dma_ops(dev);
Russell Kingafd1a322008-09-25 16:30:57 +0100893 struct scatterlist *s;
Russell King01135d922008-09-25 21:05:02 +0100894 int i, j;
Russell Kingafd1a322008-09-25 16:30:57 +0100895
896 for_each_sg(sg, s, nents, i) {
Marek Szyprowski4ce63fc2012-05-16 15:48:21 +0200897#ifdef CONFIG_NEED_SG_DMA_LENGTH
898 s->dma_length = s->length;
899#endif
Marek Szyprowski2a550e72012-02-10 19:55:20 +0100900 s->dma_address = ops->map_page(dev, sg_page(s), s->offset,
901 s->length, dir, attrs);
Russell King01135d922008-09-25 21:05:02 +0100902 if (dma_mapping_error(dev, s->dma_address))
903 goto bad_mapping;
Russell Kingafd1a322008-09-25 16:30:57 +0100904 }
Russell Kingafd1a322008-09-25 16:30:57 +0100905 return nents;
Russell King01135d922008-09-25 21:05:02 +0100906
907 bad_mapping:
908 for_each_sg(sg, s, i, j)
Marek Szyprowski2a550e72012-02-10 19:55:20 +0100909 ops->unmap_page(dev, sg_dma_address(s), sg_dma_len(s), dir, attrs);
Russell King01135d922008-09-25 21:05:02 +0100910 return 0;
Russell Kingafd1a322008-09-25 16:30:57 +0100911}
Russell Kingafd1a322008-09-25 16:30:57 +0100912
913/**
Marek Szyprowski2a550e72012-02-10 19:55:20 +0100914 * arm_dma_unmap_sg - unmap a set of SG buffers mapped by dma_map_sg
Russell Kingafd1a322008-09-25 16:30:57 +0100915 * @dev: valid struct device pointer, or NULL for ISA and EISA-like devices
916 * @sg: list of buffers
Linus Walleij0adfca62011-01-12 18:50:37 +0100917 * @nents: number of buffers to unmap (same as was passed to dma_map_sg)
Russell Kingafd1a322008-09-25 16:30:57 +0100918 * @dir: DMA transfer direction (same as was passed to dma_map_sg)
919 *
920 * Unmap a set of streaming mode DMA translations. Again, CPU access
921 * rules concerning calls here are the same as for dma_unmap_single().
922 */
Marek Szyprowski2dc6a012012-02-10 19:55:20 +0100923void arm_dma_unmap_sg(struct device *dev, struct scatterlist *sg, int nents,
924 enum dma_data_direction dir, struct dma_attrs *attrs)
Russell Kingafd1a322008-09-25 16:30:57 +0100925{
Marek Szyprowski2a550e72012-02-10 19:55:20 +0100926 struct dma_map_ops *ops = get_dma_ops(dev);
Russell King01135d922008-09-25 21:05:02 +0100927 struct scatterlist *s;
Russell King01135d922008-09-25 21:05:02 +0100928
Russell King01135d922008-09-25 21:05:02 +0100929 int i;
Russell King24056f52011-01-03 11:29:28 +0000930
Russell King01135d922008-09-25 21:05:02 +0100931 for_each_sg(sg, s, nents, i)
Marek Szyprowski2a550e72012-02-10 19:55:20 +0100932 ops->unmap_page(dev, sg_dma_address(s), sg_dma_len(s), dir, attrs);
Russell Kingafd1a322008-09-25 16:30:57 +0100933}
Russell Kingafd1a322008-09-25 16:30:57 +0100934
935/**
Marek Szyprowski2a550e72012-02-10 19:55:20 +0100936 * arm_dma_sync_sg_for_cpu
Russell Kingafd1a322008-09-25 16:30:57 +0100937 * @dev: valid struct device pointer, or NULL for ISA and EISA-like devices
938 * @sg: list of buffers
939 * @nents: number of buffers to map (returned from dma_map_sg)
940 * @dir: DMA transfer direction (same as was passed to dma_map_sg)
941 */
Marek Szyprowski2dc6a012012-02-10 19:55:20 +0100942void arm_dma_sync_sg_for_cpu(struct device *dev, struct scatterlist *sg,
Russell Kingafd1a322008-09-25 16:30:57 +0100943 int nents, enum dma_data_direction dir)
944{
Marek Szyprowski2a550e72012-02-10 19:55:20 +0100945 struct dma_map_ops *ops = get_dma_ops(dev);
Russell Kingafd1a322008-09-25 16:30:57 +0100946 struct scatterlist *s;
947 int i;
948
Marek Szyprowski2a550e72012-02-10 19:55:20 +0100949 for_each_sg(sg, s, nents, i)
950 ops->sync_single_for_cpu(dev, sg_dma_address(s), s->length,
951 dir);
Russell Kingafd1a322008-09-25 16:30:57 +0100952}
Russell Kingafd1a322008-09-25 16:30:57 +0100953
954/**
Marek Szyprowski2a550e72012-02-10 19:55:20 +0100955 * arm_dma_sync_sg_for_device
Russell Kingafd1a322008-09-25 16:30:57 +0100956 * @dev: valid struct device pointer, or NULL for ISA and EISA-like devices
957 * @sg: list of buffers
958 * @nents: number of buffers to map (returned from dma_map_sg)
959 * @dir: DMA transfer direction (same as was passed to dma_map_sg)
960 */
Marek Szyprowski2dc6a012012-02-10 19:55:20 +0100961void arm_dma_sync_sg_for_device(struct device *dev, struct scatterlist *sg,
Russell Kingafd1a322008-09-25 16:30:57 +0100962 int nents, enum dma_data_direction dir)
963{
Marek Szyprowski2a550e72012-02-10 19:55:20 +0100964 struct dma_map_ops *ops = get_dma_ops(dev);
Russell Kingafd1a322008-09-25 16:30:57 +0100965 struct scatterlist *s;
966 int i;
967
Marek Szyprowski2a550e72012-02-10 19:55:20 +0100968 for_each_sg(sg, s, nents, i)
969 ops->sync_single_for_device(dev, sg_dma_address(s), s->length,
970 dir);
Russell Kingafd1a322008-09-25 16:30:57 +0100971}
Russell King24056f52011-01-03 11:29:28 +0000972
Russell King022ae532011-07-08 21:26:59 +0100973/*
974 * Return whether the given device DMA address mask can be supported
975 * properly. For example, if your device can only drive the low 24-bits
976 * during bus mastering, then you would pass 0x00ffffff as the mask
977 * to this function.
978 */
979int dma_supported(struct device *dev, u64 mask)
980{
981 if (mask < (u64)arm_dma_limit)
982 return 0;
983 return 1;
984}
985EXPORT_SYMBOL(dma_supported);
986
Marek Szyprowski2dc6a012012-02-10 19:55:20 +0100987static int arm_dma_set_mask(struct device *dev, u64 dma_mask)
Russell King022ae532011-07-08 21:26:59 +0100988{
989 if (!dev->dma_mask || !dma_supported(dev, dma_mask))
990 return -EIO;
991
Russell King022ae532011-07-08 21:26:59 +0100992 *dev->dma_mask = dma_mask;
Russell King022ae532011-07-08 21:26:59 +0100993
994 return 0;
995}
Russell King022ae532011-07-08 21:26:59 +0100996
Russell King24056f52011-01-03 11:29:28 +0000997#define PREALLOC_DMA_DEBUG_ENTRIES 4096
998
999static int __init dma_debug_do_init(void)
1000{
Russell King45cd5292012-01-12 23:08:07 +00001001#ifdef CONFIG_MMU
1002 arm_vmregion_create_proc("dma-mappings", &consistent_head);
1003#endif
Russell King24056f52011-01-03 11:29:28 +00001004 dma_debug_init(PREALLOC_DMA_DEBUG_ENTRIES);
1005 return 0;
1006}
1007fs_initcall(dma_debug_do_init);
Marek Szyprowski4ce63fc2012-05-16 15:48:21 +02001008
1009#ifdef CONFIG_ARM_DMA_USE_IOMMU
1010
1011/* IOMMU */
1012
1013static inline dma_addr_t __alloc_iova(struct dma_iommu_mapping *mapping,
1014 size_t size)
1015{
1016 unsigned int order = get_order(size);
1017 unsigned int align = 0;
1018 unsigned int count, start;
1019 unsigned long flags;
1020
1021 count = ((PAGE_ALIGN(size) >> PAGE_SHIFT) +
1022 (1 << mapping->order) - 1) >> mapping->order;
1023
1024 if (order > mapping->order)
1025 align = (1 << (order - mapping->order)) - 1;
1026
1027 spin_lock_irqsave(&mapping->lock, flags);
1028 start = bitmap_find_next_zero_area(mapping->bitmap, mapping->bits, 0,
1029 count, align);
1030 if (start > mapping->bits) {
1031 spin_unlock_irqrestore(&mapping->lock, flags);
1032 return DMA_ERROR_CODE;
1033 }
1034
1035 bitmap_set(mapping->bitmap, start, count);
1036 spin_unlock_irqrestore(&mapping->lock, flags);
1037
1038 return mapping->base + (start << (mapping->order + PAGE_SHIFT));
1039}
1040
1041static inline void __free_iova(struct dma_iommu_mapping *mapping,
1042 dma_addr_t addr, size_t size)
1043{
1044 unsigned int start = (addr - mapping->base) >>
1045 (mapping->order + PAGE_SHIFT);
1046 unsigned int count = ((size >> PAGE_SHIFT) +
1047 (1 << mapping->order) - 1) >> mapping->order;
1048 unsigned long flags;
1049
1050 spin_lock_irqsave(&mapping->lock, flags);
1051 bitmap_clear(mapping->bitmap, start, count);
1052 spin_unlock_irqrestore(&mapping->lock, flags);
1053}
1054
1055static struct page **__iommu_alloc_buffer(struct device *dev, size_t size, gfp_t gfp)
1056{
1057 struct page **pages;
1058 int count = size >> PAGE_SHIFT;
1059 int array_size = count * sizeof(struct page *);
1060 int i = 0;
1061
1062 if (array_size <= PAGE_SIZE)
1063 pages = kzalloc(array_size, gfp);
1064 else
1065 pages = vzalloc(array_size);
1066 if (!pages)
1067 return NULL;
1068
1069 while (count) {
Marek Szyprowski593f4732012-06-21 11:48:11 +02001070 int j, order = __fls(count);
Marek Szyprowski4ce63fc2012-05-16 15:48:21 +02001071
1072 pages[i] = alloc_pages(gfp | __GFP_NOWARN, order);
1073 while (!pages[i] && order)
1074 pages[i] = alloc_pages(gfp | __GFP_NOWARN, --order);
1075 if (!pages[i])
1076 goto error;
1077
1078 if (order)
1079 split_page(pages[i], order);
1080 j = 1 << order;
1081 while (--j)
1082 pages[i + j] = pages[i] + j;
1083
1084 __dma_clear_buffer(pages[i], PAGE_SIZE << order);
1085 i += 1 << order;
1086 count -= 1 << order;
1087 }
1088
1089 return pages;
1090error:
1091 while (--i)
1092 if (pages[i])
1093 __free_pages(pages[i], 0);
Prathyush K46c87852012-07-16 08:59:55 +02001094 if (array_size <= PAGE_SIZE)
Marek Szyprowski4ce63fc2012-05-16 15:48:21 +02001095 kfree(pages);
1096 else
1097 vfree(pages);
1098 return NULL;
1099}
1100
1101static int __iommu_free_buffer(struct device *dev, struct page **pages, size_t size)
1102{
1103 int count = size >> PAGE_SHIFT;
1104 int array_size = count * sizeof(struct page *);
1105 int i;
1106 for (i = 0; i < count; i++)
1107 if (pages[i])
1108 __free_pages(pages[i], 0);
Prathyush K46c87852012-07-16 08:59:55 +02001109 if (array_size <= PAGE_SIZE)
Marek Szyprowski4ce63fc2012-05-16 15:48:21 +02001110 kfree(pages);
1111 else
1112 vfree(pages);
1113 return 0;
1114}
1115
1116/*
1117 * Create a CPU mapping for a specified pages
1118 */
1119static void *
1120__iommu_alloc_remap(struct page **pages, size_t size, gfp_t gfp, pgprot_t prot)
1121{
1122 struct arm_vmregion *c;
1123 size_t align;
1124 size_t count = size >> PAGE_SHIFT;
1125 int bit;
1126
1127 if (!consistent_pte[0]) {
1128 pr_err("%s: not initialised\n", __func__);
1129 dump_stack();
1130 return NULL;
1131 }
1132
1133 /*
1134 * Align the virtual region allocation - maximum alignment is
1135 * a section size, minimum is a page size. This helps reduce
1136 * fragmentation of the DMA space, and also prevents allocations
1137 * smaller than a section from crossing a section boundary.
1138 */
1139 bit = fls(size - 1);
1140 if (bit > SECTION_SHIFT)
1141 bit = SECTION_SHIFT;
1142 align = 1 << bit;
1143
1144 /*
1145 * Allocate a virtual address in the consistent mapping region.
1146 */
1147 c = arm_vmregion_alloc(&consistent_head, align, size,
1148 gfp & ~(__GFP_DMA | __GFP_HIGHMEM), NULL);
1149 if (c) {
1150 pte_t *pte;
1151 int idx = CONSISTENT_PTE_INDEX(c->vm_start);
1152 int i = 0;
1153 u32 off = CONSISTENT_OFFSET(c->vm_start) & (PTRS_PER_PTE-1);
1154
1155 pte = consistent_pte[idx] + off;
1156 c->priv = pages;
1157
1158 do {
1159 BUG_ON(!pte_none(*pte));
1160
1161 set_pte_ext(pte, mk_pte(pages[i], prot), 0);
1162 pte++;
1163 off++;
1164 i++;
1165 if (off >= PTRS_PER_PTE) {
1166 off = 0;
1167 pte = consistent_pte[++idx];
1168 }
1169 } while (i < count);
1170
1171 dsb();
1172
1173 return (void *)c->vm_start;
1174 }
1175 return NULL;
1176}
1177
1178/*
1179 * Create a mapping in device IO address space for specified pages
1180 */
1181static dma_addr_t
1182__iommu_create_mapping(struct device *dev, struct page **pages, size_t size)
1183{
1184 struct dma_iommu_mapping *mapping = dev->archdata.mapping;
1185 unsigned int count = PAGE_ALIGN(size) >> PAGE_SHIFT;
1186 dma_addr_t dma_addr, iova;
1187 int i, ret = DMA_ERROR_CODE;
1188
1189 dma_addr = __alloc_iova(mapping, size);
1190 if (dma_addr == DMA_ERROR_CODE)
1191 return dma_addr;
1192
1193 iova = dma_addr;
1194 for (i = 0; i < count; ) {
1195 unsigned int next_pfn = page_to_pfn(pages[i]) + 1;
1196 phys_addr_t phys = page_to_phys(pages[i]);
1197 unsigned int len, j;
1198
1199 for (j = i + 1; j < count; j++, next_pfn++)
1200 if (page_to_pfn(pages[j]) != next_pfn)
1201 break;
1202
1203 len = (j - i) << PAGE_SHIFT;
1204 ret = iommu_map(mapping->domain, iova, phys, len, 0);
1205 if (ret < 0)
1206 goto fail;
1207 iova += len;
1208 i = j;
1209 }
1210 return dma_addr;
1211fail:
1212 iommu_unmap(mapping->domain, dma_addr, iova-dma_addr);
1213 __free_iova(mapping, dma_addr, size);
1214 return DMA_ERROR_CODE;
1215}
1216
1217static int __iommu_remove_mapping(struct device *dev, dma_addr_t iova, size_t size)
1218{
1219 struct dma_iommu_mapping *mapping = dev->archdata.mapping;
1220
1221 /*
1222 * add optional in-page offset from iova to size and align
1223 * result to page size
1224 */
1225 size = PAGE_ALIGN((iova & ~PAGE_MASK) + size);
1226 iova &= PAGE_MASK;
1227
1228 iommu_unmap(mapping->domain, iova, size);
1229 __free_iova(mapping, iova, size);
1230 return 0;
1231}
1232
1233static void *arm_iommu_alloc_attrs(struct device *dev, size_t size,
1234 dma_addr_t *handle, gfp_t gfp, struct dma_attrs *attrs)
1235{
1236 pgprot_t prot = __get_dma_pgprot(attrs, pgprot_kernel);
1237 struct page **pages;
1238 void *addr = NULL;
1239
1240 *handle = DMA_ERROR_CODE;
1241 size = PAGE_ALIGN(size);
1242
1243 pages = __iommu_alloc_buffer(dev, size, gfp);
1244 if (!pages)
1245 return NULL;
1246
1247 *handle = __iommu_create_mapping(dev, pages, size);
1248 if (*handle == DMA_ERROR_CODE)
1249 goto err_buffer;
1250
1251 addr = __iommu_alloc_remap(pages, size, gfp, prot);
1252 if (!addr)
1253 goto err_mapping;
1254
1255 return addr;
1256
1257err_mapping:
1258 __iommu_remove_mapping(dev, *handle, size);
1259err_buffer:
1260 __iommu_free_buffer(dev, pages, size);
1261 return NULL;
1262}
1263
1264static int arm_iommu_mmap_attrs(struct device *dev, struct vm_area_struct *vma,
1265 void *cpu_addr, dma_addr_t dma_addr, size_t size,
1266 struct dma_attrs *attrs)
1267{
1268 struct arm_vmregion *c;
1269
1270 vma->vm_page_prot = __get_dma_pgprot(attrs, vma->vm_page_prot);
1271 c = arm_vmregion_find(&consistent_head, (unsigned long)cpu_addr);
1272
1273 if (c) {
1274 struct page **pages = c->priv;
1275
1276 unsigned long uaddr = vma->vm_start;
1277 unsigned long usize = vma->vm_end - vma->vm_start;
1278 int i = 0;
1279
1280 do {
1281 int ret;
1282
1283 ret = vm_insert_page(vma, uaddr, pages[i++]);
1284 if (ret) {
1285 pr_err("Remapping memory, error: %d\n", ret);
1286 return ret;
1287 }
1288
1289 uaddr += PAGE_SIZE;
1290 usize -= PAGE_SIZE;
1291 } while (usize > 0);
1292 }
1293 return 0;
1294}
1295
1296/*
1297 * free a page as defined by the above mapping.
1298 * Must not be called with IRQs disabled.
1299 */
1300void arm_iommu_free_attrs(struct device *dev, size_t size, void *cpu_addr,
1301 dma_addr_t handle, struct dma_attrs *attrs)
1302{
1303 struct arm_vmregion *c;
1304 size = PAGE_ALIGN(size);
1305
1306 c = arm_vmregion_find(&consistent_head, (unsigned long)cpu_addr);
1307 if (c) {
1308 struct page **pages = c->priv;
1309 __dma_free_remap(cpu_addr, size);
1310 __iommu_remove_mapping(dev, handle, size);
1311 __iommu_free_buffer(dev, pages, size);
1312 }
1313}
1314
1315/*
1316 * Map a part of the scatter-gather list into contiguous io address space
1317 */
1318static int __map_sg_chunk(struct device *dev, struct scatterlist *sg,
1319 size_t size, dma_addr_t *handle,
1320 enum dma_data_direction dir)
1321{
1322 struct dma_iommu_mapping *mapping = dev->archdata.mapping;
1323 dma_addr_t iova, iova_base;
1324 int ret = 0;
1325 unsigned int count;
1326 struct scatterlist *s;
1327
1328 size = PAGE_ALIGN(size);
1329 *handle = DMA_ERROR_CODE;
1330
1331 iova_base = iova = __alloc_iova(mapping, size);
1332 if (iova == DMA_ERROR_CODE)
1333 return -ENOMEM;
1334
1335 for (count = 0, s = sg; count < (size >> PAGE_SHIFT); s = sg_next(s)) {
1336 phys_addr_t phys = page_to_phys(sg_page(s));
1337 unsigned int len = PAGE_ALIGN(s->offset + s->length);
1338
1339 if (!arch_is_coherent())
1340 __dma_page_cpu_to_dev(sg_page(s), s->offset, s->length, dir);
1341
1342 ret = iommu_map(mapping->domain, iova, phys, len, 0);
1343 if (ret < 0)
1344 goto fail;
1345 count += len >> PAGE_SHIFT;
1346 iova += len;
1347 }
1348 *handle = iova_base;
1349
1350 return 0;
1351fail:
1352 iommu_unmap(mapping->domain, iova_base, count * PAGE_SIZE);
1353 __free_iova(mapping, iova_base, size);
1354 return ret;
1355}
1356
1357/**
1358 * arm_iommu_map_sg - map a set of SG buffers for streaming mode DMA
1359 * @dev: valid struct device pointer
1360 * @sg: list of buffers
1361 * @nents: number of buffers to map
1362 * @dir: DMA transfer direction
1363 *
1364 * Map a set of buffers described by scatterlist in streaming mode for DMA.
1365 * The scatter gather list elements are merged together (if possible) and
1366 * tagged with the appropriate dma address and length. They are obtained via
1367 * sg_dma_{address,length}.
1368 */
1369int arm_iommu_map_sg(struct device *dev, struct scatterlist *sg, int nents,
1370 enum dma_data_direction dir, struct dma_attrs *attrs)
1371{
1372 struct scatterlist *s = sg, *dma = sg, *start = sg;
1373 int i, count = 0;
1374 unsigned int offset = s->offset;
1375 unsigned int size = s->offset + s->length;
1376 unsigned int max = dma_get_max_seg_size(dev);
1377
1378 for (i = 1; i < nents; i++) {
1379 s = sg_next(s);
1380
1381 s->dma_address = DMA_ERROR_CODE;
1382 s->dma_length = 0;
1383
1384 if (s->offset || (size & ~PAGE_MASK) || size + s->length > max) {
1385 if (__map_sg_chunk(dev, start, size, &dma->dma_address,
1386 dir) < 0)
1387 goto bad_mapping;
1388
1389 dma->dma_address += offset;
1390 dma->dma_length = size - offset;
1391
1392 size = offset = s->offset;
1393 start = s;
1394 dma = sg_next(dma);
1395 count += 1;
1396 }
1397 size += s->length;
1398 }
1399 if (__map_sg_chunk(dev, start, size, &dma->dma_address, dir) < 0)
1400 goto bad_mapping;
1401
1402 dma->dma_address += offset;
1403 dma->dma_length = size - offset;
1404
1405 return count+1;
1406
1407bad_mapping:
1408 for_each_sg(sg, s, count, i)
1409 __iommu_remove_mapping(dev, sg_dma_address(s), sg_dma_len(s));
1410 return 0;
1411}
1412
1413/**
1414 * arm_iommu_unmap_sg - unmap a set of SG buffers mapped by dma_map_sg
1415 * @dev: valid struct device pointer
1416 * @sg: list of buffers
1417 * @nents: number of buffers to unmap (same as was passed to dma_map_sg)
1418 * @dir: DMA transfer direction (same as was passed to dma_map_sg)
1419 *
1420 * Unmap a set of streaming mode DMA translations. Again, CPU access
1421 * rules concerning calls here are the same as for dma_unmap_single().
1422 */
1423void arm_iommu_unmap_sg(struct device *dev, struct scatterlist *sg, int nents,
1424 enum dma_data_direction dir, struct dma_attrs *attrs)
1425{
1426 struct scatterlist *s;
1427 int i;
1428
1429 for_each_sg(sg, s, nents, i) {
1430 if (sg_dma_len(s))
1431 __iommu_remove_mapping(dev, sg_dma_address(s),
1432 sg_dma_len(s));
1433 if (!arch_is_coherent())
1434 __dma_page_dev_to_cpu(sg_page(s), s->offset,
1435 s->length, dir);
1436 }
1437}
1438
1439/**
1440 * arm_iommu_sync_sg_for_cpu
1441 * @dev: valid struct device pointer
1442 * @sg: list of buffers
1443 * @nents: number of buffers to map (returned from dma_map_sg)
1444 * @dir: DMA transfer direction (same as was passed to dma_map_sg)
1445 */
1446void arm_iommu_sync_sg_for_cpu(struct device *dev, struct scatterlist *sg,
1447 int nents, enum dma_data_direction dir)
1448{
1449 struct scatterlist *s;
1450 int i;
1451
1452 for_each_sg(sg, s, nents, i)
1453 if (!arch_is_coherent())
1454 __dma_page_dev_to_cpu(sg_page(s), s->offset, s->length, dir);
1455
1456}
1457
1458/**
1459 * arm_iommu_sync_sg_for_device
1460 * @dev: valid struct device pointer
1461 * @sg: list of buffers
1462 * @nents: number of buffers to map (returned from dma_map_sg)
1463 * @dir: DMA transfer direction (same as was passed to dma_map_sg)
1464 */
1465void arm_iommu_sync_sg_for_device(struct device *dev, struct scatterlist *sg,
1466 int nents, enum dma_data_direction dir)
1467{
1468 struct scatterlist *s;
1469 int i;
1470
1471 for_each_sg(sg, s, nents, i)
1472 if (!arch_is_coherent())
1473 __dma_page_cpu_to_dev(sg_page(s), s->offset, s->length, dir);
1474}
1475
1476
1477/**
1478 * arm_iommu_map_page
1479 * @dev: valid struct device pointer
1480 * @page: page that buffer resides in
1481 * @offset: offset into page for start of buffer
1482 * @size: size of buffer to map
1483 * @dir: DMA transfer direction
1484 *
1485 * IOMMU aware version of arm_dma_map_page()
1486 */
1487static dma_addr_t arm_iommu_map_page(struct device *dev, struct page *page,
1488 unsigned long offset, size_t size, enum dma_data_direction dir,
1489 struct dma_attrs *attrs)
1490{
1491 struct dma_iommu_mapping *mapping = dev->archdata.mapping;
1492 dma_addr_t dma_addr;
1493 int ret, len = PAGE_ALIGN(size + offset);
1494
1495 if (!arch_is_coherent())
1496 __dma_page_cpu_to_dev(page, offset, size, dir);
1497
1498 dma_addr = __alloc_iova(mapping, len);
1499 if (dma_addr == DMA_ERROR_CODE)
1500 return dma_addr;
1501
1502 ret = iommu_map(mapping->domain, dma_addr, page_to_phys(page), len, 0);
1503 if (ret < 0)
1504 goto fail;
1505
1506 return dma_addr + offset;
1507fail:
1508 __free_iova(mapping, dma_addr, len);
1509 return DMA_ERROR_CODE;
1510}
1511
1512/**
1513 * arm_iommu_unmap_page
1514 * @dev: valid struct device pointer
1515 * @handle: DMA address of buffer
1516 * @size: size of buffer (same as passed to dma_map_page)
1517 * @dir: DMA transfer direction (same as passed to dma_map_page)
1518 *
1519 * IOMMU aware version of arm_dma_unmap_page()
1520 */
1521static void arm_iommu_unmap_page(struct device *dev, dma_addr_t handle,
1522 size_t size, enum dma_data_direction dir,
1523 struct dma_attrs *attrs)
1524{
1525 struct dma_iommu_mapping *mapping = dev->archdata.mapping;
1526 dma_addr_t iova = handle & PAGE_MASK;
1527 struct page *page = phys_to_page(iommu_iova_to_phys(mapping->domain, iova));
1528 int offset = handle & ~PAGE_MASK;
1529 int len = PAGE_ALIGN(size + offset);
1530
1531 if (!iova)
1532 return;
1533
1534 if (!arch_is_coherent())
1535 __dma_page_dev_to_cpu(page, offset, size, dir);
1536
1537 iommu_unmap(mapping->domain, iova, len);
1538 __free_iova(mapping, iova, len);
1539}
1540
1541static void arm_iommu_sync_single_for_cpu(struct device *dev,
1542 dma_addr_t handle, size_t size, enum dma_data_direction dir)
1543{
1544 struct dma_iommu_mapping *mapping = dev->archdata.mapping;
1545 dma_addr_t iova = handle & PAGE_MASK;
1546 struct page *page = phys_to_page(iommu_iova_to_phys(mapping->domain, iova));
1547 unsigned int offset = handle & ~PAGE_MASK;
1548
1549 if (!iova)
1550 return;
1551
1552 if (!arch_is_coherent())
1553 __dma_page_dev_to_cpu(page, offset, size, dir);
1554}
1555
1556static void arm_iommu_sync_single_for_device(struct device *dev,
1557 dma_addr_t handle, size_t size, enum dma_data_direction dir)
1558{
1559 struct dma_iommu_mapping *mapping = dev->archdata.mapping;
1560 dma_addr_t iova = handle & PAGE_MASK;
1561 struct page *page = phys_to_page(iommu_iova_to_phys(mapping->domain, iova));
1562 unsigned int offset = handle & ~PAGE_MASK;
1563
1564 if (!iova)
1565 return;
1566
1567 __dma_page_cpu_to_dev(page, offset, size, dir);
1568}
1569
1570struct dma_map_ops iommu_ops = {
1571 .alloc = arm_iommu_alloc_attrs,
1572 .free = arm_iommu_free_attrs,
1573 .mmap = arm_iommu_mmap_attrs,
1574
1575 .map_page = arm_iommu_map_page,
1576 .unmap_page = arm_iommu_unmap_page,
1577 .sync_single_for_cpu = arm_iommu_sync_single_for_cpu,
1578 .sync_single_for_device = arm_iommu_sync_single_for_device,
1579
1580 .map_sg = arm_iommu_map_sg,
1581 .unmap_sg = arm_iommu_unmap_sg,
1582 .sync_sg_for_cpu = arm_iommu_sync_sg_for_cpu,
1583 .sync_sg_for_device = arm_iommu_sync_sg_for_device,
1584};
1585
1586/**
1587 * arm_iommu_create_mapping
1588 * @bus: pointer to the bus holding the client device (for IOMMU calls)
1589 * @base: start address of the valid IO address space
1590 * @size: size of the valid IO address space
1591 * @order: accuracy of the IO addresses allocations
1592 *
1593 * Creates a mapping structure which holds information about used/unused
1594 * IO address ranges, which is required to perform memory allocation and
1595 * mapping with IOMMU aware functions.
1596 *
1597 * The client device need to be attached to the mapping with
1598 * arm_iommu_attach_device function.
1599 */
1600struct dma_iommu_mapping *
1601arm_iommu_create_mapping(struct bus_type *bus, dma_addr_t base, size_t size,
1602 int order)
1603{
1604 unsigned int count = size >> (PAGE_SHIFT + order);
1605 unsigned int bitmap_size = BITS_TO_LONGS(count) * sizeof(long);
1606 struct dma_iommu_mapping *mapping;
1607 int err = -ENOMEM;
1608
1609 if (!count)
1610 return ERR_PTR(-EINVAL);
1611
1612 mapping = kzalloc(sizeof(struct dma_iommu_mapping), GFP_KERNEL);
1613 if (!mapping)
1614 goto err;
1615
1616 mapping->bitmap = kzalloc(bitmap_size, GFP_KERNEL);
1617 if (!mapping->bitmap)
1618 goto err2;
1619
1620 mapping->base = base;
1621 mapping->bits = BITS_PER_BYTE * bitmap_size;
1622 mapping->order = order;
1623 spin_lock_init(&mapping->lock);
1624
1625 mapping->domain = iommu_domain_alloc(bus);
1626 if (!mapping->domain)
1627 goto err3;
1628
1629 kref_init(&mapping->kref);
1630 return mapping;
1631err3:
1632 kfree(mapping->bitmap);
1633err2:
1634 kfree(mapping);
1635err:
1636 return ERR_PTR(err);
1637}
1638
1639static void release_iommu_mapping(struct kref *kref)
1640{
1641 struct dma_iommu_mapping *mapping =
1642 container_of(kref, struct dma_iommu_mapping, kref);
1643
1644 iommu_domain_free(mapping->domain);
1645 kfree(mapping->bitmap);
1646 kfree(mapping);
1647}
1648
1649void arm_iommu_release_mapping(struct dma_iommu_mapping *mapping)
1650{
1651 if (mapping)
1652 kref_put(&mapping->kref, release_iommu_mapping);
1653}
1654
1655/**
1656 * arm_iommu_attach_device
1657 * @dev: valid struct device pointer
1658 * @mapping: io address space mapping structure (returned from
1659 * arm_iommu_create_mapping)
1660 *
1661 * Attaches specified io address space mapping to the provided device,
1662 * this replaces the dma operations (dma_map_ops pointer) with the
1663 * IOMMU aware version. More than one client might be attached to
1664 * the same io address space mapping.
1665 */
1666int arm_iommu_attach_device(struct device *dev,
1667 struct dma_iommu_mapping *mapping)
1668{
1669 int err;
1670
1671 err = iommu_attach_device(mapping->domain, dev);
1672 if (err)
1673 return err;
1674
1675 kref_get(&mapping->kref);
1676 dev->archdata.mapping = mapping;
1677 set_dma_ops(dev, &iommu_ops);
1678
1679 pr_info("Attached IOMMU controller to %s device.\n", dev_name(dev));
1680 return 0;
1681}
1682
1683#endif