2 * linux/arch/arm/mm/dma-mapping.c
4 * Copyright (C) 2000-2004 Russell King
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.
10 * DMA uncached mapping support.
12 #include <linux/module.h>
14 #include <linux/gfp.h>
15 #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>
20 #include <linux/highmem.h>
21 #include <linux/slab.h>
23 #include <asm/memory.h>
24 #include <asm/highmem.h>
25 #include <asm/cacheflush.h>
26 #include <asm/tlbflush.h>
27 #include <asm/sizes.h>
28 #include <asm/mach/arch.h>
32 static u64 get_coherent_dma_mask(struct device *dev)
34 u64 mask = (u64)arm_dma_limit;
37 mask = dev->coherent_dma_mask;
40 * Sanity check the DMA mask - it must be non-zero, and
41 * must be able to be satisfied by a DMA allocation.
44 dev_warn(dev, "coherent DMA mask is unset\n");
48 if ((~mask) & (u64)arm_dma_limit) {
49 dev_warn(dev, "coherent DMA mask %#llx is smaller "
50 "than system GFP_DMA mask %#llx\n",
51 mask, (u64)arm_dma_limit);
60 * Allocate a DMA buffer for 'dev' of size 'size' using the
61 * specified gfp mask. Note that 'size' must be page aligned.
63 static struct page *__dma_alloc_buffer(struct device *dev, size_t size, gfp_t gfp)
65 unsigned long order = get_order(size);
66 struct page *page, *p, *e;
68 u64 mask = get_coherent_dma_mask(dev);
70 #ifdef CONFIG_DMA_API_DEBUG
71 u64 limit = (mask + 1) & ~mask;
72 if (limit && size >= limit) {
73 dev_warn(dev, "coherent allocation too big (requested %#x mask %#llx)\n",
82 if (mask < 0xffffffffULL)
85 page = alloc_pages(gfp, order);
90 * Now split the huge page and free the excess pages
92 split_page(page, order);
93 for (p = page + (size >> PAGE_SHIFT), e = page + (1 << order); p < e; p++)
97 * Ensure that the allocated pages are zeroed, and that any data
98 * lurking in the kernel direct-mapped region is invalidated.
100 ptr = page_address(page);
101 memset(ptr, 0, size);
102 dmac_flush_range(ptr, ptr + size);
103 outer_flush_range(__pa(ptr), __pa(ptr) + size);
109 * Free a DMA buffer. 'size' must be page aligned.
111 static void __dma_free_buffer(struct page *page, size_t size)
113 struct page *e = page + (size >> PAGE_SHIFT);
123 #define CONSISTENT_OFFSET(x) (((unsigned long)(x) - consistent_base) >> PAGE_SHIFT)
124 #define CONSISTENT_PTE_INDEX(x) (((unsigned long)(x) - consistent_base) >> PMD_SHIFT)
127 * These are the page tables (2MB each) covering uncached, DMA consistent allocations
129 static pte_t **consistent_pte;
131 #define DEFAULT_CONSISTENT_DMA_SIZE SZ_2M
133 unsigned long consistent_base = CONSISTENT_END - DEFAULT_CONSISTENT_DMA_SIZE;
135 void __init init_consistent_dma_size(unsigned long size)
137 unsigned long base = CONSISTENT_END - ALIGN(size, SZ_2M);
139 BUG_ON(consistent_pte); /* Check we're called before DMA region init */
140 BUG_ON(base < VMALLOC_END);
142 /* Grow region to accommodate specified size */
143 if (base < consistent_base)
144 consistent_base = base;
147 #include "vmregion.h"
149 static struct arm_vmregion_head consistent_head = {
150 .vm_lock = __SPIN_LOCK_UNLOCKED(&consistent_head.vm_lock),
151 .vm_list = LIST_HEAD_INIT(consistent_head.vm_list),
152 .vm_end = CONSISTENT_END,
155 #ifdef CONFIG_HUGETLB_PAGE
156 #error ARM Coherent DMA allocator does not (yet) support huge TLB
160 * Initialise the consistent memory allocation.
162 static int __init consistent_init(void)
170 unsigned long base = consistent_base;
171 unsigned long num_ptes = (CONSISTENT_END - base) >> PMD_SHIFT;
173 consistent_pte = kmalloc(num_ptes * sizeof(pte_t), GFP_KERNEL);
174 if (!consistent_pte) {
175 pr_err("%s: no memory\n", __func__);
179 pr_debug("DMA memory: 0x%08lx - 0x%08lx:\n", base, CONSISTENT_END);
180 consistent_head.vm_start = base;
183 pgd = pgd_offset(&init_mm, base);
185 pud = pud_alloc(&init_mm, pgd, base);
187 printk(KERN_ERR "%s: no pud tables\n", __func__);
192 pmd = pmd_alloc(&init_mm, pud, base);
194 printk(KERN_ERR "%s: no pmd tables\n", __func__);
198 WARN_ON(!pmd_none(*pmd));
200 pte = pte_alloc_kernel(pmd, base);
202 printk(KERN_ERR "%s: no pte tables\n", __func__);
207 consistent_pte[i++] = pte;
209 } while (base < CONSISTENT_END);
214 core_initcall(consistent_init);
217 __dma_alloc_remap(struct page *page, size_t size, gfp_t gfp, pgprot_t prot,
220 struct arm_vmregion *c;
224 if (!consistent_pte) {
225 printk(KERN_ERR "%s: not initialised\n", __func__);
231 * Align the virtual region allocation - maximum alignment is
232 * a section size, minimum is a page size. This helps reduce
233 * fragmentation of the DMA space, and also prevents allocations
234 * smaller than a section from crossing a section boundary.
237 if (bit > SECTION_SHIFT)
242 * Allocate a virtual address in the consistent mapping region.
244 c = arm_vmregion_alloc(&consistent_head, align, size,
245 gfp & ~(__GFP_DMA | __GFP_HIGHMEM), caller);
248 int idx = CONSISTENT_PTE_INDEX(c->vm_start);
249 u32 off = CONSISTENT_OFFSET(c->vm_start) & (PTRS_PER_PTE-1);
251 pte = consistent_pte[idx] + off;
255 BUG_ON(!pte_none(*pte));
257 set_pte_ext(pte, mk_pte(page, prot), 0);
261 if (off >= PTRS_PER_PTE) {
263 pte = consistent_pte[++idx];
265 } while (size -= PAGE_SIZE);
269 return (void *)c->vm_start;
274 static void __dma_free_remap(void *cpu_addr, size_t size)
276 struct arm_vmregion *c;
282 c = arm_vmregion_find_remove(&consistent_head, (unsigned long)cpu_addr);
284 printk(KERN_ERR "%s: trying to free invalid coherent area: %p\n",
290 if ((c->vm_end - c->vm_start) != size) {
291 printk(KERN_ERR "%s: freeing wrong coherent size (%ld != %d)\n",
292 __func__, c->vm_end - c->vm_start, size);
294 size = c->vm_end - c->vm_start;
297 idx = CONSISTENT_PTE_INDEX(c->vm_start);
298 off = CONSISTENT_OFFSET(c->vm_start) & (PTRS_PER_PTE-1);
299 ptep = consistent_pte[idx] + off;
302 pte_t pte = ptep_get_and_clear(&init_mm, addr, ptep);
307 if (off >= PTRS_PER_PTE) {
309 ptep = consistent_pte[++idx];
312 if (pte_none(pte) || !pte_present(pte))
313 printk(KERN_CRIT "%s: bad page in kernel page table\n",
315 } while (size -= PAGE_SIZE);
317 flush_tlb_kernel_range(c->vm_start, c->vm_end);
319 arm_vmregion_free(&consistent_head, c);
322 #else /* !CONFIG_MMU */
324 #define __dma_alloc_remap(page, size, gfp, prot, c) page_address(page)
325 #define __dma_free_remap(addr, size) do { } while (0)
327 #endif /* CONFIG_MMU */
330 __dma_alloc(struct device *dev, size_t size, dma_addr_t *handle, gfp_t gfp,
331 pgprot_t prot, const void *caller)
337 * Following is a work-around (a.k.a. hack) to prevent pages
338 * with __GFP_COMP being passed to split_page() which cannot
339 * handle them. The real problem is that this flag probably
340 * should be 0 on ARM as it is not supported on this
341 * platform; see CONFIG_HUGETLBFS.
343 gfp &= ~(__GFP_COMP);
346 size = PAGE_ALIGN(size);
348 page = __dma_alloc_buffer(dev, size, gfp);
352 if (!arch_is_coherent())
353 addr = __dma_alloc_remap(page, size, gfp, prot, caller);
355 addr = page_address(page);
358 *handle = pfn_to_dma(dev, page_to_pfn(page));
360 __dma_free_buffer(page, size);
366 * Allocate DMA-coherent memory space and return both the kernel remapped
367 * virtual and bus address for that space.
370 dma_alloc_coherent(struct device *dev, size_t size, dma_addr_t *handle, gfp_t gfp)
374 if (dma_alloc_from_coherent(dev, size, handle, &memory))
377 return __dma_alloc(dev, size, handle, gfp,
378 pgprot_dmacoherent(pgprot_kernel),
379 __builtin_return_address(0));
381 EXPORT_SYMBOL(dma_alloc_coherent);
384 * Allocate a writecombining region, in much the same way as
385 * dma_alloc_coherent above.
388 dma_alloc_writecombine(struct device *dev, size_t size, dma_addr_t *handle, gfp_t gfp)
390 return __dma_alloc(dev, size, handle, gfp,
391 pgprot_writecombine(pgprot_kernel),
392 __builtin_return_address(0));
394 EXPORT_SYMBOL(dma_alloc_writecombine);
396 static int dma_mmap(struct device *dev, struct vm_area_struct *vma,
397 void *cpu_addr, dma_addr_t dma_addr, size_t size)
401 unsigned long user_size, kern_size;
402 struct arm_vmregion *c;
404 user_size = (vma->vm_end - vma->vm_start) >> PAGE_SHIFT;
406 c = arm_vmregion_find(&consistent_head, (unsigned long)cpu_addr);
408 unsigned long off = vma->vm_pgoff;
410 kern_size = (c->vm_end - c->vm_start) >> PAGE_SHIFT;
412 if (off < kern_size &&
413 user_size <= (kern_size - off)) {
414 ret = remap_pfn_range(vma, vma->vm_start,
415 page_to_pfn(c->vm_pages) + off,
416 user_size << PAGE_SHIFT,
420 #endif /* CONFIG_MMU */
425 int dma_mmap_coherent(struct device *dev, struct vm_area_struct *vma,
426 void *cpu_addr, dma_addr_t dma_addr, size_t size)
428 vma->vm_page_prot = pgprot_dmacoherent(vma->vm_page_prot);
429 return dma_mmap(dev, vma, cpu_addr, dma_addr, size);
431 EXPORT_SYMBOL(dma_mmap_coherent);
433 int dma_mmap_writecombine(struct device *dev, struct vm_area_struct *vma,
434 void *cpu_addr, dma_addr_t dma_addr, size_t size)
436 vma->vm_page_prot = pgprot_writecombine(vma->vm_page_prot);
437 return dma_mmap(dev, vma, cpu_addr, dma_addr, size);
439 EXPORT_SYMBOL(dma_mmap_writecombine);
442 * free a page as defined by the above mapping.
443 * Must not be called with IRQs disabled.
445 void dma_free_coherent(struct device *dev, size_t size, void *cpu_addr, dma_addr_t handle)
447 WARN_ON(irqs_disabled());
449 if (dma_release_from_coherent(dev, get_order(size), cpu_addr))
452 size = PAGE_ALIGN(size);
454 if (!arch_is_coherent())
455 __dma_free_remap(cpu_addr, size);
457 __dma_free_buffer(pfn_to_page(dma_to_pfn(dev, handle)), size);
459 EXPORT_SYMBOL(dma_free_coherent);
462 * Make an area consistent for devices.
463 * Note: Drivers should NOT use this function directly, as it will break
464 * platforms with CONFIG_DMABOUNCE.
465 * Use the driver DMA support - see dma-mapping.h (dma_sync_*)
467 void ___dma_single_cpu_to_dev(const void *kaddr, size_t size,
468 enum dma_data_direction dir)
472 BUG_ON(!virt_addr_valid(kaddr) || !virt_addr_valid(kaddr + size - 1));
474 dmac_map_area(kaddr, size, dir);
477 if (dir == DMA_FROM_DEVICE) {
478 outer_inv_range(paddr, paddr + size);
480 outer_clean_range(paddr, paddr + size);
482 /* FIXME: non-speculating: flush on bidirectional mappings? */
484 EXPORT_SYMBOL(___dma_single_cpu_to_dev);
486 void ___dma_single_dev_to_cpu(const void *kaddr, size_t size,
487 enum dma_data_direction dir)
489 BUG_ON(!virt_addr_valid(kaddr) || !virt_addr_valid(kaddr + size - 1));
491 /* FIXME: non-speculating: not required */
492 /* don't bother invalidating if DMA to device */
493 if (dir != DMA_TO_DEVICE) {
494 unsigned long paddr = __pa(kaddr);
495 outer_inv_range(paddr, paddr + size);
498 dmac_unmap_area(kaddr, size, dir);
500 EXPORT_SYMBOL(___dma_single_dev_to_cpu);
502 static void dma_cache_maint_page(struct page *page, unsigned long offset,
503 size_t size, enum dma_data_direction dir,
504 void (*op)(const void *, size_t, int))
507 * A single sg entry may refer to multiple physically contiguous
508 * pages. But we still need to process highmem pages individually.
509 * If highmem is not configured then the bulk of this loop gets
517 if (PageHighMem(page)) {
518 if (len + offset > PAGE_SIZE) {
519 if (offset >= PAGE_SIZE) {
520 page += offset / PAGE_SIZE;
523 len = PAGE_SIZE - offset;
525 vaddr = kmap_high_get(page);
530 } else if (cache_is_vipt()) {
531 /* unmapped pages might still be cached */
532 vaddr = kmap_atomic(page);
533 op(vaddr + offset, len, dir);
534 kunmap_atomic(vaddr);
537 vaddr = page_address(page) + offset;
546 void ___dma_page_cpu_to_dev(struct page *page, unsigned long off,
547 size_t size, enum dma_data_direction dir)
551 dma_cache_maint_page(page, off, size, dir, dmac_map_area);
553 paddr = page_to_phys(page) + off;
554 if (dir == DMA_FROM_DEVICE) {
555 outer_inv_range(paddr, paddr + size);
557 outer_clean_range(paddr, paddr + size);
559 /* FIXME: non-speculating: flush on bidirectional mappings? */
561 EXPORT_SYMBOL(___dma_page_cpu_to_dev);
563 void ___dma_page_dev_to_cpu(struct page *page, unsigned long off,
564 size_t size, enum dma_data_direction dir)
566 unsigned long paddr = page_to_phys(page) + off;
568 /* FIXME: non-speculating: not required */
569 /* don't bother invalidating if DMA to device */
570 if (dir != DMA_TO_DEVICE)
571 outer_inv_range(paddr, paddr + size);
573 dma_cache_maint_page(page, off, size, dir, dmac_unmap_area);
576 * Mark the D-cache clean for this page to avoid extra flushing.
578 if (dir != DMA_TO_DEVICE && off == 0 && size >= PAGE_SIZE)
579 set_bit(PG_dcache_clean, &page->flags);
581 EXPORT_SYMBOL(___dma_page_dev_to_cpu);
584 * dma_map_sg - map a set of SG buffers for streaming mode DMA
585 * @dev: valid struct device pointer, or NULL for ISA and EISA-like devices
586 * @sg: list of buffers
587 * @nents: number of buffers to map
588 * @dir: DMA transfer direction
590 * Map a set of buffers described by scatterlist in streaming mode for DMA.
591 * This is the scatter-gather version of the dma_map_single interface.
592 * Here the scatter gather list elements are each tagged with the
593 * appropriate dma address and length. They are obtained via
594 * sg_dma_{address,length}.
596 * Device ownership issues as mentioned for dma_map_single are the same
599 int dma_map_sg(struct device *dev, struct scatterlist *sg, int nents,
600 enum dma_data_direction dir)
602 struct scatterlist *s;
605 BUG_ON(!valid_dma_direction(dir));
607 for_each_sg(sg, s, nents, i) {
608 s->dma_address = __dma_map_page(dev, sg_page(s), s->offset,
610 if (dma_mapping_error(dev, s->dma_address))
613 debug_dma_map_sg(dev, sg, nents, nents, dir);
617 for_each_sg(sg, s, i, j)
618 __dma_unmap_page(dev, sg_dma_address(s), sg_dma_len(s), dir);
621 EXPORT_SYMBOL(dma_map_sg);
624 * dma_unmap_sg - unmap a set of SG buffers mapped by dma_map_sg
625 * @dev: valid struct device pointer, or NULL for ISA and EISA-like devices
626 * @sg: list of buffers
627 * @nents: number of buffers to unmap (same as was passed to dma_map_sg)
628 * @dir: DMA transfer direction (same as was passed to dma_map_sg)
630 * Unmap a set of streaming mode DMA translations. Again, CPU access
631 * rules concerning calls here are the same as for dma_unmap_single().
633 void dma_unmap_sg(struct device *dev, struct scatterlist *sg, int nents,
634 enum dma_data_direction dir)
636 struct scatterlist *s;
639 debug_dma_unmap_sg(dev, sg, nents, dir);
641 for_each_sg(sg, s, nents, i)
642 __dma_unmap_page(dev, sg_dma_address(s), sg_dma_len(s), dir);
644 EXPORT_SYMBOL(dma_unmap_sg);
647 * dma_sync_sg_for_cpu
648 * @dev: valid struct device pointer, or NULL for ISA and EISA-like devices
649 * @sg: list of buffers
650 * @nents: number of buffers to map (returned from dma_map_sg)
651 * @dir: DMA transfer direction (same as was passed to dma_map_sg)
653 void dma_sync_sg_for_cpu(struct device *dev, struct scatterlist *sg,
654 int nents, enum dma_data_direction dir)
656 struct scatterlist *s;
659 for_each_sg(sg, s, nents, i) {
660 if (!dmabounce_sync_for_cpu(dev, sg_dma_address(s), 0,
664 __dma_page_dev_to_cpu(sg_page(s), s->offset,
668 debug_dma_sync_sg_for_cpu(dev, sg, nents, dir);
670 EXPORT_SYMBOL(dma_sync_sg_for_cpu);
673 * dma_sync_sg_for_device
674 * @dev: valid struct device pointer, or NULL for ISA and EISA-like devices
675 * @sg: list of buffers
676 * @nents: number of buffers to map (returned from dma_map_sg)
677 * @dir: DMA transfer direction (same as was passed to dma_map_sg)
679 void dma_sync_sg_for_device(struct device *dev, struct scatterlist *sg,
680 int nents, enum dma_data_direction dir)
682 struct scatterlist *s;
685 for_each_sg(sg, s, nents, i) {
686 if (!dmabounce_sync_for_device(dev, sg_dma_address(s), 0,
690 __dma_page_cpu_to_dev(sg_page(s), s->offset,
694 debug_dma_sync_sg_for_device(dev, sg, nents, dir);
696 EXPORT_SYMBOL(dma_sync_sg_for_device);
699 * Return whether the given device DMA address mask can be supported
700 * properly. For example, if your device can only drive the low 24-bits
701 * during bus mastering, then you would pass 0x00ffffff as the mask
704 int dma_supported(struct device *dev, u64 mask)
706 if (mask < (u64)arm_dma_limit)
710 EXPORT_SYMBOL(dma_supported);
712 int dma_set_mask(struct device *dev, u64 dma_mask)
714 if (!dev->dma_mask || !dma_supported(dev, dma_mask))
717 #ifndef CONFIG_DMABOUNCE
718 *dev->dma_mask = dma_mask;
723 EXPORT_SYMBOL(dma_set_mask);
725 #define PREALLOC_DMA_DEBUG_ENTRIES 4096
727 static int __init dma_debug_do_init(void)
730 arm_vmregion_create_proc("dma-mappings", &consistent_head);
732 dma_debug_init(PREALLOC_DMA_DEBUG_ENTRIES);
735 fs_initcall(dma_debug_do_init);