Merge branch 'for-next-arm-dma' into for-linus
Conflicts:
arch/arm/Kconfig
arch/arm/mm/dma-mapping.c
Signed-off-by: Marek Szyprowski <m.szyprowski@samsung.com>
diff --git a/arch/arm/mm/dma-mapping.c b/arch/arm/mm/dma-mapping.c
index 153f555..ea6b431 100644
--- a/arch/arm/mm/dma-mapping.c
+++ b/arch/arm/mm/dma-mapping.c
@@ -21,6 +21,8 @@
#include <linux/highmem.h>
#include <linux/memblock.h>
#include <linux/slab.h>
+#include <linux/iommu.h>
+#include <linux/vmalloc.h>
#include <asm/memory.h>
#include <asm/highmem.h>
@@ -28,12 +30,112 @@
#include <asm/tlbflush.h>
#include <asm/sizes.h>
#include <asm/mach/arch.h>
+#include <asm/dma-iommu.h>
#include <asm/mach/map.h>
#include <asm/system_info.h>
#include <asm/dma-contiguous.h>
#include "mm.h"
+/*
+ * The DMA API is built upon the notion of "buffer ownership". A buffer
+ * is either exclusively owned by the CPU (and therefore may be accessed
+ * by it) or exclusively owned by the DMA device. These helper functions
+ * represent the transitions between these two ownership states.
+ *
+ * Note, however, that on later ARMs, this notion does not work due to
+ * speculative prefetches. We model our approach on the assumption that
+ * the CPU does do speculative prefetches, which means we clean caches
+ * before transfers and delay cache invalidation until transfer completion.
+ *
+ */
+static void __dma_page_cpu_to_dev(struct page *, unsigned long,
+ size_t, enum dma_data_direction);
+static void __dma_page_dev_to_cpu(struct page *, unsigned long,
+ size_t, enum dma_data_direction);
+
+/**
+ * arm_dma_map_page - map a portion of a page for streaming DMA
+ * @dev: valid struct device pointer, or NULL for ISA and EISA-like devices
+ * @page: page that buffer resides in
+ * @offset: offset into page for start of buffer
+ * @size: size of buffer to map
+ * @dir: DMA transfer direction
+ *
+ * Ensure that any data held in the cache is appropriately discarded
+ * or written back.
+ *
+ * The device owns this memory once this call has completed. The CPU
+ * can regain ownership by calling dma_unmap_page().
+ */
+static dma_addr_t arm_dma_map_page(struct device *dev, struct page *page,
+ unsigned long offset, size_t size, enum dma_data_direction dir,
+ struct dma_attrs *attrs)
+{
+ if (!arch_is_coherent())
+ __dma_page_cpu_to_dev(page, offset, size, dir);
+ return pfn_to_dma(dev, page_to_pfn(page)) + offset;
+}
+
+/**
+ * arm_dma_unmap_page - unmap a buffer previously mapped through dma_map_page()
+ * @dev: valid struct device pointer, or NULL for ISA and EISA-like devices
+ * @handle: DMA address of buffer
+ * @size: size of buffer (same as passed to dma_map_page)
+ * @dir: DMA transfer direction (same as passed to dma_map_page)
+ *
+ * Unmap a page streaming mode DMA translation. The handle and size
+ * must match what was provided in the previous dma_map_page() call.
+ * All other usages are undefined.
+ *
+ * After this call, reads by the CPU to the buffer are guaranteed to see
+ * whatever the device wrote there.
+ */
+static void arm_dma_unmap_page(struct device *dev, dma_addr_t handle,
+ size_t size, enum dma_data_direction dir,
+ struct dma_attrs *attrs)
+{
+ if (!arch_is_coherent())
+ __dma_page_dev_to_cpu(pfn_to_page(dma_to_pfn(dev, handle)),
+ handle & ~PAGE_MASK, size, dir);
+}
+
+static void arm_dma_sync_single_for_cpu(struct device *dev,
+ dma_addr_t handle, size_t size, enum dma_data_direction dir)
+{
+ unsigned int offset = handle & (PAGE_SIZE - 1);
+ struct page *page = pfn_to_page(dma_to_pfn(dev, handle-offset));
+ if (!arch_is_coherent())
+ __dma_page_dev_to_cpu(page, offset, size, dir);
+}
+
+static void arm_dma_sync_single_for_device(struct device *dev,
+ dma_addr_t handle, size_t size, enum dma_data_direction dir)
+{
+ unsigned int offset = handle & (PAGE_SIZE - 1);
+ struct page *page = pfn_to_page(dma_to_pfn(dev, handle-offset));
+ if (!arch_is_coherent())
+ __dma_page_cpu_to_dev(page, offset, size, dir);
+}
+
+static int arm_dma_set_mask(struct device *dev, u64 dma_mask);
+
+struct dma_map_ops arm_dma_ops = {
+ .alloc = arm_dma_alloc,
+ .free = arm_dma_free,
+ .mmap = arm_dma_mmap,
+ .map_page = arm_dma_map_page,
+ .unmap_page = arm_dma_unmap_page,
+ .map_sg = arm_dma_map_sg,
+ .unmap_sg = arm_dma_unmap_sg,
+ .sync_single_for_cpu = arm_dma_sync_single_for_cpu,
+ .sync_single_for_device = arm_dma_sync_single_for_device,
+ .sync_sg_for_cpu = arm_dma_sync_sg_for_cpu,
+ .sync_sg_for_device = arm_dma_sync_sg_for_device,
+ .set_dma_mask = arm_dma_set_mask,
+};
+EXPORT_SYMBOL(arm_dma_ops);
+
static u64 get_coherent_dma_mask(struct device *dev)
{
u64 mask = (u64)arm_dma_limit;
@@ -69,9 +171,11 @@
* lurking in the kernel direct-mapped region is invalidated.
*/
ptr = page_address(page);
- memset(ptr, 0, size);
- dmac_flush_range(ptr, ptr + size);
- outer_flush_range(__pa(ptr), __pa(ptr) + size);
+ if (ptr) {
+ memset(ptr, 0, size);
+ dmac_flush_range(ptr, ptr + size);
+ outer_flush_range(__pa(ptr), __pa(ptr) + size);
+ }
}
/*
@@ -164,8 +268,10 @@
unsigned long base = consistent_base;
unsigned long num_ptes = (CONSISTENT_END - base) >> PMD_SHIFT;
+#ifndef CONFIG_ARM_DMA_USE_IOMMU
if (cpu_architecture() >= CPU_ARCH_ARMv6)
return 0;
+#endif
consistent_pte = kmalloc(num_ptes * sizeof(pte_t), GFP_KERNEL);
if (!consistent_pte) {
@@ -181,14 +287,14 @@
pud = pud_alloc(&init_mm, pgd, base);
if (!pud) {
- printk(KERN_ERR "%s: no pud tables\n", __func__);
+ pr_err("%s: no pud tables\n", __func__);
ret = -ENOMEM;
break;
}
pmd = pmd_alloc(&init_mm, pud, base);
if (!pmd) {
- printk(KERN_ERR "%s: no pmd tables\n", __func__);
+ pr_err("%s: no pmd tables\n", __func__);
ret = -ENOMEM;
break;
}
@@ -196,7 +302,7 @@
pte = pte_alloc_kernel(pmd, base);
if (!pte) {
- printk(KERN_ERR "%s: no pte tables\n", __func__);
+ pr_err("%s: no pte tables\n", __func__);
ret = -ENOMEM;
break;
}
@@ -311,7 +417,7 @@
int bit;
if (!consistent_pte) {
- printk(KERN_ERR "%s: not initialised\n", __func__);
+ pr_err("%s: not initialised\n", __func__);
dump_stack();
return NULL;
}
@@ -338,7 +444,7 @@
u32 off = CONSISTENT_OFFSET(c->vm_start) & (PTRS_PER_PTE-1);
pte = consistent_pte[idx] + off;
- c->vm_pages = page;
+ c->priv = page;
do {
BUG_ON(!pte_none(*pte));
@@ -370,14 +476,14 @@
c = arm_vmregion_find_remove(&consistent_head, (unsigned long)cpu_addr);
if (!c) {
- printk(KERN_ERR "%s: trying to free invalid coherent area: %p\n",
+ pr_err("%s: trying to free invalid coherent area: %p\n",
__func__, cpu_addr);
dump_stack();
return;
}
if ((c->vm_end - c->vm_start) != size) {
- printk(KERN_ERR "%s: freeing wrong coherent size (%ld != %d)\n",
+ pr_err("%s: freeing wrong coherent size (%ld != %d)\n",
__func__, c->vm_end - c->vm_start, size);
dump_stack();
size = c->vm_end - c->vm_start;
@@ -399,8 +505,8 @@
}
if (pte_none(pte) || !pte_present(pte))
- printk(KERN_CRIT "%s: bad page in kernel page table\n",
- __func__);
+ pr_crit("%s: bad page in kernel page table\n",
+ __func__);
} while (size -= PAGE_SIZE);
flush_tlb_kernel_range(c->vm_start, c->vm_end);
@@ -524,12 +630,21 @@
dma_release_from_contiguous(dev, page, size >> PAGE_SHIFT);
}
+static inline pgprot_t __get_dma_pgprot(struct dma_attrs *attrs, pgprot_t prot)
+{
+ prot = dma_get_attr(DMA_ATTR_WRITE_COMBINE, attrs) ?
+ pgprot_writecombine(prot) :
+ pgprot_dmacoherent(prot);
+ return prot;
+}
+
#define nommu() 0
#else /* !CONFIG_MMU */
#define nommu() 1
+#define __get_dma_pgprot(attrs, prot) __pgprot(0)
#define __alloc_remap_buffer(dev, size, gfp, prot, ret, c) NULL
#define __alloc_from_pool(dev, size, ret_page, c) NULL
#define __alloc_from_contiguous(dev, size, prot, ret) NULL
@@ -584,7 +699,7 @@
*/
gfp &= ~(__GFP_COMP);
- *handle = ~0;
+ *handle = DMA_ERROR_CODE;
size = PAGE_ALIGN(size);
if (arch_is_coherent() || nommu())
@@ -606,39 +721,34 @@
* Allocate DMA-coherent memory space and return both the kernel remapped
* virtual and bus address for that space.
*/
-void *dma_alloc_coherent(struct device *dev, size_t size, dma_addr_t *handle,
- gfp_t gfp)
+void *arm_dma_alloc(struct device *dev, size_t size, dma_addr_t *handle,
+ gfp_t gfp, struct dma_attrs *attrs)
{
+ pgprot_t prot = __get_dma_pgprot(attrs, pgprot_kernel);
void *memory;
if (dma_alloc_from_coherent(dev, size, handle, &memory))
return memory;
- return __dma_alloc(dev, size, handle, gfp,
- pgprot_dmacoherent(pgprot_kernel),
+ return __dma_alloc(dev, size, handle, gfp, prot,
__builtin_return_address(0));
}
-EXPORT_SYMBOL(dma_alloc_coherent);
/*
- * Allocate a writecombining region, in much the same way as
- * dma_alloc_coherent above.
+ * Create userspace mapping for the DMA-coherent memory.
*/
-void *
-dma_alloc_writecombine(struct device *dev, size_t size, dma_addr_t *handle, gfp_t gfp)
-{
- return __dma_alloc(dev, size, handle, gfp,
- pgprot_writecombine(pgprot_kernel),
- __builtin_return_address(0));
-}
-EXPORT_SYMBOL(dma_alloc_writecombine);
-
-static int dma_mmap(struct device *dev, struct vm_area_struct *vma,
- void *cpu_addr, dma_addr_t dma_addr, size_t size)
+int arm_dma_mmap(struct device *dev, struct vm_area_struct *vma,
+ void *cpu_addr, dma_addr_t dma_addr, size_t size,
+ struct dma_attrs *attrs)
{
int ret = -ENXIO;
#ifdef CONFIG_MMU
unsigned long pfn = dma_to_pfn(dev, dma_addr);
+ vma->vm_page_prot = __get_dma_pgprot(attrs, vma->vm_page_prot);
+
+ if (dma_mmap_from_coherent(dev, vma, cpu_addr, size, &ret))
+ return ret;
+
ret = remap_pfn_range(vma, vma->vm_start,
pfn + vma->vm_pgoff,
vma->vm_end - vma->vm_start,
@@ -648,27 +758,11 @@
return ret;
}
-int dma_mmap_coherent(struct device *dev, struct vm_area_struct *vma,
- void *cpu_addr, dma_addr_t dma_addr, size_t size)
-{
- vma->vm_page_prot = pgprot_dmacoherent(vma->vm_page_prot);
- return dma_mmap(dev, vma, cpu_addr, dma_addr, size);
-}
-EXPORT_SYMBOL(dma_mmap_coherent);
-
-int dma_mmap_writecombine(struct device *dev, struct vm_area_struct *vma,
- void *cpu_addr, dma_addr_t dma_addr, size_t size)
-{
- vma->vm_page_prot = pgprot_writecombine(vma->vm_page_prot);
- return dma_mmap(dev, vma, cpu_addr, dma_addr, size);
-}
-EXPORT_SYMBOL(dma_mmap_writecombine);
-
-
/*
* Free a buffer as defined by the above mapping.
*/
-void dma_free_coherent(struct device *dev, size_t size, void *cpu_addr, dma_addr_t handle)
+void arm_dma_free(struct device *dev, size_t size, void *cpu_addr,
+ dma_addr_t handle, struct dma_attrs *attrs)
{
struct page *page = pfn_to_page(dma_to_pfn(dev, handle));
@@ -692,48 +786,6 @@
__free_from_contiguous(dev, page, size);
}
}
-EXPORT_SYMBOL(dma_free_coherent);
-
-/*
- * Make an area consistent for devices.
- * Note: Drivers should NOT use this function directly, as it will break
- * platforms with CONFIG_DMABOUNCE.
- * Use the driver DMA support - see dma-mapping.h (dma_sync_*)
- */
-void ___dma_single_cpu_to_dev(const void *kaddr, size_t size,
- enum dma_data_direction dir)
-{
- unsigned long paddr;
-
- BUG_ON(!virt_addr_valid(kaddr) || !virt_addr_valid(kaddr + size - 1));
-
- dmac_map_area(kaddr, size, dir);
-
- paddr = __pa(kaddr);
- if (dir == DMA_FROM_DEVICE) {
- outer_inv_range(paddr, paddr + size);
- } else {
- outer_clean_range(paddr, paddr + size);
- }
- /* FIXME: non-speculating: flush on bidirectional mappings? */
-}
-EXPORT_SYMBOL(___dma_single_cpu_to_dev);
-
-void ___dma_single_dev_to_cpu(const void *kaddr, size_t size,
- enum dma_data_direction dir)
-{
- BUG_ON(!virt_addr_valid(kaddr) || !virt_addr_valid(kaddr + size - 1));
-
- /* FIXME: non-speculating: not required */
- /* don't bother invalidating if DMA to device */
- if (dir != DMA_TO_DEVICE) {
- unsigned long paddr = __pa(kaddr);
- outer_inv_range(paddr, paddr + size);
- }
-
- dmac_unmap_area(kaddr, size, dir);
-}
-EXPORT_SYMBOL(___dma_single_dev_to_cpu);
static void dma_cache_maint_page(struct page *page, unsigned long offset,
size_t size, enum dma_data_direction dir,
@@ -779,7 +831,13 @@
} while (left);
}
-void ___dma_page_cpu_to_dev(struct page *page, unsigned long off,
+/*
+ * Make an area consistent for devices.
+ * Note: Drivers should NOT use this function directly, as it will break
+ * platforms with CONFIG_DMABOUNCE.
+ * Use the driver DMA support - see dma-mapping.h (dma_sync_*)
+ */
+static void __dma_page_cpu_to_dev(struct page *page, unsigned long off,
size_t size, enum dma_data_direction dir)
{
unsigned long paddr;
@@ -794,9 +852,8 @@
}
/* FIXME: non-speculating: flush on bidirectional mappings? */
}
-EXPORT_SYMBOL(___dma_page_cpu_to_dev);
-void ___dma_page_dev_to_cpu(struct page *page, unsigned long off,
+static void __dma_page_dev_to_cpu(struct page *page, unsigned long off,
size_t size, enum dma_data_direction dir)
{
unsigned long paddr = page_to_phys(page) + off;
@@ -814,10 +871,9 @@
if (dir != DMA_TO_DEVICE && off == 0 && size >= PAGE_SIZE)
set_bit(PG_dcache_clean, &page->flags);
}
-EXPORT_SYMBOL(___dma_page_dev_to_cpu);
/**
- * dma_map_sg - map a set of SG buffers for streaming mode DMA
+ * arm_dma_map_sg - map a set of SG buffers for streaming mode DMA
* @dev: valid struct device pointer, or NULL for ISA and EISA-like devices
* @sg: list of buffers
* @nents: number of buffers to map
@@ -832,32 +888,32 @@
* Device ownership issues as mentioned for dma_map_single are the same
* here.
*/
-int dma_map_sg(struct device *dev, struct scatterlist *sg, int nents,
- enum dma_data_direction dir)
+int arm_dma_map_sg(struct device *dev, struct scatterlist *sg, int nents,
+ enum dma_data_direction dir, struct dma_attrs *attrs)
{
+ struct dma_map_ops *ops = get_dma_ops(dev);
struct scatterlist *s;
int i, j;
- BUG_ON(!valid_dma_direction(dir));
-
for_each_sg(sg, s, nents, i) {
- s->dma_address = __dma_map_page(dev, sg_page(s), s->offset,
- s->length, dir);
+#ifdef CONFIG_NEED_SG_DMA_LENGTH
+ s->dma_length = s->length;
+#endif
+ s->dma_address = ops->map_page(dev, sg_page(s), s->offset,
+ s->length, dir, attrs);
if (dma_mapping_error(dev, s->dma_address))
goto bad_mapping;
}
- debug_dma_map_sg(dev, sg, nents, nents, dir);
return nents;
bad_mapping:
for_each_sg(sg, s, i, j)
- __dma_unmap_page(dev, sg_dma_address(s), sg_dma_len(s), dir);
+ ops->unmap_page(dev, sg_dma_address(s), sg_dma_len(s), dir, attrs);
return 0;
}
-EXPORT_SYMBOL(dma_map_sg);
/**
- * dma_unmap_sg - unmap a set of SG buffers mapped by dma_map_sg
+ * arm_dma_unmap_sg - unmap a set of SG buffers mapped by dma_map_sg
* @dev: valid struct device pointer, or NULL for ISA and EISA-like devices
* @sg: list of buffers
* @nents: number of buffers to unmap (same as was passed to dma_map_sg)
@@ -866,70 +922,55 @@
* Unmap a set of streaming mode DMA translations. Again, CPU access
* rules concerning calls here are the same as for dma_unmap_single().
*/
-void dma_unmap_sg(struct device *dev, struct scatterlist *sg, int nents,
- enum dma_data_direction dir)
+void arm_dma_unmap_sg(struct device *dev, struct scatterlist *sg, int nents,
+ enum dma_data_direction dir, struct dma_attrs *attrs)
{
+ struct dma_map_ops *ops = get_dma_ops(dev);
struct scatterlist *s;
- int i;
- debug_dma_unmap_sg(dev, sg, nents, dir);
+ int i;
for_each_sg(sg, s, nents, i)
- __dma_unmap_page(dev, sg_dma_address(s), sg_dma_len(s), dir);
+ ops->unmap_page(dev, sg_dma_address(s), sg_dma_len(s), dir, attrs);
}
-EXPORT_SYMBOL(dma_unmap_sg);
/**
- * dma_sync_sg_for_cpu
+ * arm_dma_sync_sg_for_cpu
* @dev: valid struct device pointer, or NULL for ISA and EISA-like devices
* @sg: list of buffers
* @nents: number of buffers to map (returned from dma_map_sg)
* @dir: DMA transfer direction (same as was passed to dma_map_sg)
*/
-void dma_sync_sg_for_cpu(struct device *dev, struct scatterlist *sg,
+void arm_dma_sync_sg_for_cpu(struct device *dev, struct scatterlist *sg,
int nents, enum dma_data_direction dir)
{
+ struct dma_map_ops *ops = get_dma_ops(dev);
struct scatterlist *s;
int i;
- for_each_sg(sg, s, nents, i) {
- if (!dmabounce_sync_for_cpu(dev, sg_dma_address(s), 0,
- sg_dma_len(s), dir))
- continue;
-
- __dma_page_dev_to_cpu(sg_page(s), s->offset,
- s->length, dir);
- }
-
- debug_dma_sync_sg_for_cpu(dev, sg, nents, dir);
+ for_each_sg(sg, s, nents, i)
+ ops->sync_single_for_cpu(dev, sg_dma_address(s), s->length,
+ dir);
}
-EXPORT_SYMBOL(dma_sync_sg_for_cpu);
/**
- * dma_sync_sg_for_device
+ * arm_dma_sync_sg_for_device
* @dev: valid struct device pointer, or NULL for ISA and EISA-like devices
* @sg: list of buffers
* @nents: number of buffers to map (returned from dma_map_sg)
* @dir: DMA transfer direction (same as was passed to dma_map_sg)
*/
-void dma_sync_sg_for_device(struct device *dev, struct scatterlist *sg,
+void arm_dma_sync_sg_for_device(struct device *dev, struct scatterlist *sg,
int nents, enum dma_data_direction dir)
{
+ struct dma_map_ops *ops = get_dma_ops(dev);
struct scatterlist *s;
int i;
- for_each_sg(sg, s, nents, i) {
- if (!dmabounce_sync_for_device(dev, sg_dma_address(s), 0,
- sg_dma_len(s), dir))
- continue;
-
- __dma_page_cpu_to_dev(sg_page(s), s->offset,
- s->length, dir);
- }
-
- debug_dma_sync_sg_for_device(dev, sg, nents, dir);
+ for_each_sg(sg, s, nents, i)
+ ops->sync_single_for_device(dev, sg_dma_address(s), s->length,
+ dir);
}
-EXPORT_SYMBOL(dma_sync_sg_for_device);
/*
* Return whether the given device DMA address mask can be supported
@@ -945,18 +986,15 @@
}
EXPORT_SYMBOL(dma_supported);
-int dma_set_mask(struct device *dev, u64 dma_mask)
+static int arm_dma_set_mask(struct device *dev, u64 dma_mask)
{
if (!dev->dma_mask || !dma_supported(dev, dma_mask))
return -EIO;
-#ifndef CONFIG_DMABOUNCE
*dev->dma_mask = dma_mask;
-#endif
return 0;
}
-EXPORT_SYMBOL(dma_set_mask);
#define PREALLOC_DMA_DEBUG_ENTRIES 4096
@@ -969,3 +1007,679 @@
return 0;
}
fs_initcall(dma_debug_do_init);
+
+#ifdef CONFIG_ARM_DMA_USE_IOMMU
+
+/* IOMMU */
+
+static inline dma_addr_t __alloc_iova(struct dma_iommu_mapping *mapping,
+ size_t size)
+{
+ unsigned int order = get_order(size);
+ unsigned int align = 0;
+ unsigned int count, start;
+ unsigned long flags;
+
+ count = ((PAGE_ALIGN(size) >> PAGE_SHIFT) +
+ (1 << mapping->order) - 1) >> mapping->order;
+
+ if (order > mapping->order)
+ align = (1 << (order - mapping->order)) - 1;
+
+ spin_lock_irqsave(&mapping->lock, flags);
+ start = bitmap_find_next_zero_area(mapping->bitmap, mapping->bits, 0,
+ count, align);
+ if (start > mapping->bits) {
+ spin_unlock_irqrestore(&mapping->lock, flags);
+ return DMA_ERROR_CODE;
+ }
+
+ bitmap_set(mapping->bitmap, start, count);
+ spin_unlock_irqrestore(&mapping->lock, flags);
+
+ return mapping->base + (start << (mapping->order + PAGE_SHIFT));
+}
+
+static inline void __free_iova(struct dma_iommu_mapping *mapping,
+ dma_addr_t addr, size_t size)
+{
+ unsigned int start = (addr - mapping->base) >>
+ (mapping->order + PAGE_SHIFT);
+ unsigned int count = ((size >> PAGE_SHIFT) +
+ (1 << mapping->order) - 1) >> mapping->order;
+ unsigned long flags;
+
+ spin_lock_irqsave(&mapping->lock, flags);
+ bitmap_clear(mapping->bitmap, start, count);
+ spin_unlock_irqrestore(&mapping->lock, flags);
+}
+
+static struct page **__iommu_alloc_buffer(struct device *dev, size_t size, gfp_t gfp)
+{
+ struct page **pages;
+ int count = size >> PAGE_SHIFT;
+ int array_size = count * sizeof(struct page *);
+ int i = 0;
+
+ if (array_size <= PAGE_SIZE)
+ pages = kzalloc(array_size, gfp);
+ else
+ pages = vzalloc(array_size);
+ if (!pages)
+ return NULL;
+
+ while (count) {
+ int j, order = __ffs(count);
+
+ pages[i] = alloc_pages(gfp | __GFP_NOWARN, order);
+ while (!pages[i] && order)
+ pages[i] = alloc_pages(gfp | __GFP_NOWARN, --order);
+ if (!pages[i])
+ goto error;
+
+ if (order)
+ split_page(pages[i], order);
+ j = 1 << order;
+ while (--j)
+ pages[i + j] = pages[i] + j;
+
+ __dma_clear_buffer(pages[i], PAGE_SIZE << order);
+ i += 1 << order;
+ count -= 1 << order;
+ }
+
+ return pages;
+error:
+ while (--i)
+ if (pages[i])
+ __free_pages(pages[i], 0);
+ if (array_size < PAGE_SIZE)
+ kfree(pages);
+ else
+ vfree(pages);
+ return NULL;
+}
+
+static int __iommu_free_buffer(struct device *dev, struct page **pages, size_t size)
+{
+ int count = size >> PAGE_SHIFT;
+ int array_size = count * sizeof(struct page *);
+ int i;
+ for (i = 0; i < count; i++)
+ if (pages[i])
+ __free_pages(pages[i], 0);
+ if (array_size < PAGE_SIZE)
+ kfree(pages);
+ else
+ vfree(pages);
+ return 0;
+}
+
+/*
+ * Create a CPU mapping for a specified pages
+ */
+static void *
+__iommu_alloc_remap(struct page **pages, size_t size, gfp_t gfp, pgprot_t prot)
+{
+ struct arm_vmregion *c;
+ size_t align;
+ size_t count = size >> PAGE_SHIFT;
+ int bit;
+
+ if (!consistent_pte[0]) {
+ pr_err("%s: not initialised\n", __func__);
+ dump_stack();
+ return NULL;
+ }
+
+ /*
+ * Align the virtual region allocation - maximum alignment is
+ * a section size, minimum is a page size. This helps reduce
+ * fragmentation of the DMA space, and also prevents allocations
+ * smaller than a section from crossing a section boundary.
+ */
+ bit = fls(size - 1);
+ if (bit > SECTION_SHIFT)
+ bit = SECTION_SHIFT;
+ align = 1 << bit;
+
+ /*
+ * Allocate a virtual address in the consistent mapping region.
+ */
+ c = arm_vmregion_alloc(&consistent_head, align, size,
+ gfp & ~(__GFP_DMA | __GFP_HIGHMEM), NULL);
+ if (c) {
+ pte_t *pte;
+ int idx = CONSISTENT_PTE_INDEX(c->vm_start);
+ int i = 0;
+ u32 off = CONSISTENT_OFFSET(c->vm_start) & (PTRS_PER_PTE-1);
+
+ pte = consistent_pte[idx] + off;
+ c->priv = pages;
+
+ do {
+ BUG_ON(!pte_none(*pte));
+
+ set_pte_ext(pte, mk_pte(pages[i], prot), 0);
+ pte++;
+ off++;
+ i++;
+ if (off >= PTRS_PER_PTE) {
+ off = 0;
+ pte = consistent_pte[++idx];
+ }
+ } while (i < count);
+
+ dsb();
+
+ return (void *)c->vm_start;
+ }
+ return NULL;
+}
+
+/*
+ * Create a mapping in device IO address space for specified pages
+ */
+static dma_addr_t
+__iommu_create_mapping(struct device *dev, struct page **pages, size_t size)
+{
+ struct dma_iommu_mapping *mapping = dev->archdata.mapping;
+ unsigned int count = PAGE_ALIGN(size) >> PAGE_SHIFT;
+ dma_addr_t dma_addr, iova;
+ int i, ret = DMA_ERROR_CODE;
+
+ dma_addr = __alloc_iova(mapping, size);
+ if (dma_addr == DMA_ERROR_CODE)
+ return dma_addr;
+
+ iova = dma_addr;
+ for (i = 0; i < count; ) {
+ unsigned int next_pfn = page_to_pfn(pages[i]) + 1;
+ phys_addr_t phys = page_to_phys(pages[i]);
+ unsigned int len, j;
+
+ for (j = i + 1; j < count; j++, next_pfn++)
+ if (page_to_pfn(pages[j]) != next_pfn)
+ break;
+
+ len = (j - i) << PAGE_SHIFT;
+ ret = iommu_map(mapping->domain, iova, phys, len, 0);
+ if (ret < 0)
+ goto fail;
+ iova += len;
+ i = j;
+ }
+ return dma_addr;
+fail:
+ iommu_unmap(mapping->domain, dma_addr, iova-dma_addr);
+ __free_iova(mapping, dma_addr, size);
+ return DMA_ERROR_CODE;
+}
+
+static int __iommu_remove_mapping(struct device *dev, dma_addr_t iova, size_t size)
+{
+ struct dma_iommu_mapping *mapping = dev->archdata.mapping;
+
+ /*
+ * add optional in-page offset from iova to size and align
+ * result to page size
+ */
+ size = PAGE_ALIGN((iova & ~PAGE_MASK) + size);
+ iova &= PAGE_MASK;
+
+ iommu_unmap(mapping->domain, iova, size);
+ __free_iova(mapping, iova, size);
+ return 0;
+}
+
+static void *arm_iommu_alloc_attrs(struct device *dev, size_t size,
+ dma_addr_t *handle, gfp_t gfp, struct dma_attrs *attrs)
+{
+ pgprot_t prot = __get_dma_pgprot(attrs, pgprot_kernel);
+ struct page **pages;
+ void *addr = NULL;
+
+ *handle = DMA_ERROR_CODE;
+ size = PAGE_ALIGN(size);
+
+ pages = __iommu_alloc_buffer(dev, size, gfp);
+ if (!pages)
+ return NULL;
+
+ *handle = __iommu_create_mapping(dev, pages, size);
+ if (*handle == DMA_ERROR_CODE)
+ goto err_buffer;
+
+ addr = __iommu_alloc_remap(pages, size, gfp, prot);
+ if (!addr)
+ goto err_mapping;
+
+ return addr;
+
+err_mapping:
+ __iommu_remove_mapping(dev, *handle, size);
+err_buffer:
+ __iommu_free_buffer(dev, pages, size);
+ return NULL;
+}
+
+static int arm_iommu_mmap_attrs(struct device *dev, struct vm_area_struct *vma,
+ void *cpu_addr, dma_addr_t dma_addr, size_t size,
+ struct dma_attrs *attrs)
+{
+ struct arm_vmregion *c;
+
+ vma->vm_page_prot = __get_dma_pgprot(attrs, vma->vm_page_prot);
+ c = arm_vmregion_find(&consistent_head, (unsigned long)cpu_addr);
+
+ if (c) {
+ struct page **pages = c->priv;
+
+ unsigned long uaddr = vma->vm_start;
+ unsigned long usize = vma->vm_end - vma->vm_start;
+ int i = 0;
+
+ do {
+ int ret;
+
+ ret = vm_insert_page(vma, uaddr, pages[i++]);
+ if (ret) {
+ pr_err("Remapping memory, error: %d\n", ret);
+ return ret;
+ }
+
+ uaddr += PAGE_SIZE;
+ usize -= PAGE_SIZE;
+ } while (usize > 0);
+ }
+ return 0;
+}
+
+/*
+ * free a page as defined by the above mapping.
+ * Must not be called with IRQs disabled.
+ */
+void arm_iommu_free_attrs(struct device *dev, size_t size, void *cpu_addr,
+ dma_addr_t handle, struct dma_attrs *attrs)
+{
+ struct arm_vmregion *c;
+ size = PAGE_ALIGN(size);
+
+ c = arm_vmregion_find(&consistent_head, (unsigned long)cpu_addr);
+ if (c) {
+ struct page **pages = c->priv;
+ __dma_free_remap(cpu_addr, size);
+ __iommu_remove_mapping(dev, handle, size);
+ __iommu_free_buffer(dev, pages, size);
+ }
+}
+
+/*
+ * Map a part of the scatter-gather list into contiguous io address space
+ */
+static int __map_sg_chunk(struct device *dev, struct scatterlist *sg,
+ size_t size, dma_addr_t *handle,
+ enum dma_data_direction dir)
+{
+ struct dma_iommu_mapping *mapping = dev->archdata.mapping;
+ dma_addr_t iova, iova_base;
+ int ret = 0;
+ unsigned int count;
+ struct scatterlist *s;
+
+ size = PAGE_ALIGN(size);
+ *handle = DMA_ERROR_CODE;
+
+ iova_base = iova = __alloc_iova(mapping, size);
+ if (iova == DMA_ERROR_CODE)
+ return -ENOMEM;
+
+ for (count = 0, s = sg; count < (size >> PAGE_SHIFT); s = sg_next(s)) {
+ phys_addr_t phys = page_to_phys(sg_page(s));
+ unsigned int len = PAGE_ALIGN(s->offset + s->length);
+
+ if (!arch_is_coherent())
+ __dma_page_cpu_to_dev(sg_page(s), s->offset, s->length, dir);
+
+ ret = iommu_map(mapping->domain, iova, phys, len, 0);
+ if (ret < 0)
+ goto fail;
+ count += len >> PAGE_SHIFT;
+ iova += len;
+ }
+ *handle = iova_base;
+
+ return 0;
+fail:
+ iommu_unmap(mapping->domain, iova_base, count * PAGE_SIZE);
+ __free_iova(mapping, iova_base, size);
+ return ret;
+}
+
+/**
+ * arm_iommu_map_sg - map a set of SG buffers for streaming mode DMA
+ * @dev: valid struct device pointer
+ * @sg: list of buffers
+ * @nents: number of buffers to map
+ * @dir: DMA transfer direction
+ *
+ * Map a set of buffers described by scatterlist in streaming mode for DMA.
+ * The scatter gather list elements are merged together (if possible) and
+ * tagged with the appropriate dma address and length. They are obtained via
+ * sg_dma_{address,length}.
+ */
+int arm_iommu_map_sg(struct device *dev, struct scatterlist *sg, int nents,
+ enum dma_data_direction dir, struct dma_attrs *attrs)
+{
+ struct scatterlist *s = sg, *dma = sg, *start = sg;
+ int i, count = 0;
+ unsigned int offset = s->offset;
+ unsigned int size = s->offset + s->length;
+ unsigned int max = dma_get_max_seg_size(dev);
+
+ for (i = 1; i < nents; i++) {
+ s = sg_next(s);
+
+ s->dma_address = DMA_ERROR_CODE;
+ s->dma_length = 0;
+
+ if (s->offset || (size & ~PAGE_MASK) || size + s->length > max) {
+ if (__map_sg_chunk(dev, start, size, &dma->dma_address,
+ dir) < 0)
+ goto bad_mapping;
+
+ dma->dma_address += offset;
+ dma->dma_length = size - offset;
+
+ size = offset = s->offset;
+ start = s;
+ dma = sg_next(dma);
+ count += 1;
+ }
+ size += s->length;
+ }
+ if (__map_sg_chunk(dev, start, size, &dma->dma_address, dir) < 0)
+ goto bad_mapping;
+
+ dma->dma_address += offset;
+ dma->dma_length = size - offset;
+
+ return count+1;
+
+bad_mapping:
+ for_each_sg(sg, s, count, i)
+ __iommu_remove_mapping(dev, sg_dma_address(s), sg_dma_len(s));
+ return 0;
+}
+
+/**
+ * arm_iommu_unmap_sg - unmap a set of SG buffers mapped by dma_map_sg
+ * @dev: valid struct device pointer
+ * @sg: list of buffers
+ * @nents: number of buffers to unmap (same as was passed to dma_map_sg)
+ * @dir: DMA transfer direction (same as was passed to dma_map_sg)
+ *
+ * Unmap a set of streaming mode DMA translations. Again, CPU access
+ * rules concerning calls here are the same as for dma_unmap_single().
+ */
+void arm_iommu_unmap_sg(struct device *dev, struct scatterlist *sg, int nents,
+ enum dma_data_direction dir, struct dma_attrs *attrs)
+{
+ struct scatterlist *s;
+ int i;
+
+ for_each_sg(sg, s, nents, i) {
+ if (sg_dma_len(s))
+ __iommu_remove_mapping(dev, sg_dma_address(s),
+ sg_dma_len(s));
+ if (!arch_is_coherent())
+ __dma_page_dev_to_cpu(sg_page(s), s->offset,
+ s->length, dir);
+ }
+}
+
+/**
+ * arm_iommu_sync_sg_for_cpu
+ * @dev: valid struct device pointer
+ * @sg: list of buffers
+ * @nents: number of buffers to map (returned from dma_map_sg)
+ * @dir: DMA transfer direction (same as was passed to dma_map_sg)
+ */
+void arm_iommu_sync_sg_for_cpu(struct device *dev, struct scatterlist *sg,
+ int nents, enum dma_data_direction dir)
+{
+ struct scatterlist *s;
+ int i;
+
+ for_each_sg(sg, s, nents, i)
+ if (!arch_is_coherent())
+ __dma_page_dev_to_cpu(sg_page(s), s->offset, s->length, dir);
+
+}
+
+/**
+ * arm_iommu_sync_sg_for_device
+ * @dev: valid struct device pointer
+ * @sg: list of buffers
+ * @nents: number of buffers to map (returned from dma_map_sg)
+ * @dir: DMA transfer direction (same as was passed to dma_map_sg)
+ */
+void arm_iommu_sync_sg_for_device(struct device *dev, struct scatterlist *sg,
+ int nents, enum dma_data_direction dir)
+{
+ struct scatterlist *s;
+ int i;
+
+ for_each_sg(sg, s, nents, i)
+ if (!arch_is_coherent())
+ __dma_page_cpu_to_dev(sg_page(s), s->offset, s->length, dir);
+}
+
+
+/**
+ * arm_iommu_map_page
+ * @dev: valid struct device pointer
+ * @page: page that buffer resides in
+ * @offset: offset into page for start of buffer
+ * @size: size of buffer to map
+ * @dir: DMA transfer direction
+ *
+ * IOMMU aware version of arm_dma_map_page()
+ */
+static dma_addr_t arm_iommu_map_page(struct device *dev, struct page *page,
+ unsigned long offset, size_t size, enum dma_data_direction dir,
+ struct dma_attrs *attrs)
+{
+ struct dma_iommu_mapping *mapping = dev->archdata.mapping;
+ dma_addr_t dma_addr;
+ int ret, len = PAGE_ALIGN(size + offset);
+
+ if (!arch_is_coherent())
+ __dma_page_cpu_to_dev(page, offset, size, dir);
+
+ dma_addr = __alloc_iova(mapping, len);
+ if (dma_addr == DMA_ERROR_CODE)
+ return dma_addr;
+
+ ret = iommu_map(mapping->domain, dma_addr, page_to_phys(page), len, 0);
+ if (ret < 0)
+ goto fail;
+
+ return dma_addr + offset;
+fail:
+ __free_iova(mapping, dma_addr, len);
+ return DMA_ERROR_CODE;
+}
+
+/**
+ * arm_iommu_unmap_page
+ * @dev: valid struct device pointer
+ * @handle: DMA address of buffer
+ * @size: size of buffer (same as passed to dma_map_page)
+ * @dir: DMA transfer direction (same as passed to dma_map_page)
+ *
+ * IOMMU aware version of arm_dma_unmap_page()
+ */
+static void arm_iommu_unmap_page(struct device *dev, dma_addr_t handle,
+ size_t size, enum dma_data_direction dir,
+ struct dma_attrs *attrs)
+{
+ struct dma_iommu_mapping *mapping = dev->archdata.mapping;
+ dma_addr_t iova = handle & PAGE_MASK;
+ struct page *page = phys_to_page(iommu_iova_to_phys(mapping->domain, iova));
+ int offset = handle & ~PAGE_MASK;
+ int len = PAGE_ALIGN(size + offset);
+
+ if (!iova)
+ return;
+
+ if (!arch_is_coherent())
+ __dma_page_dev_to_cpu(page, offset, size, dir);
+
+ iommu_unmap(mapping->domain, iova, len);
+ __free_iova(mapping, iova, len);
+}
+
+static void arm_iommu_sync_single_for_cpu(struct device *dev,
+ dma_addr_t handle, size_t size, enum dma_data_direction dir)
+{
+ struct dma_iommu_mapping *mapping = dev->archdata.mapping;
+ dma_addr_t iova = handle & PAGE_MASK;
+ struct page *page = phys_to_page(iommu_iova_to_phys(mapping->domain, iova));
+ unsigned int offset = handle & ~PAGE_MASK;
+
+ if (!iova)
+ return;
+
+ if (!arch_is_coherent())
+ __dma_page_dev_to_cpu(page, offset, size, dir);
+}
+
+static void arm_iommu_sync_single_for_device(struct device *dev,
+ dma_addr_t handle, size_t size, enum dma_data_direction dir)
+{
+ struct dma_iommu_mapping *mapping = dev->archdata.mapping;
+ dma_addr_t iova = handle & PAGE_MASK;
+ struct page *page = phys_to_page(iommu_iova_to_phys(mapping->domain, iova));
+ unsigned int offset = handle & ~PAGE_MASK;
+
+ if (!iova)
+ return;
+
+ __dma_page_cpu_to_dev(page, offset, size, dir);
+}
+
+struct dma_map_ops iommu_ops = {
+ .alloc = arm_iommu_alloc_attrs,
+ .free = arm_iommu_free_attrs,
+ .mmap = arm_iommu_mmap_attrs,
+
+ .map_page = arm_iommu_map_page,
+ .unmap_page = arm_iommu_unmap_page,
+ .sync_single_for_cpu = arm_iommu_sync_single_for_cpu,
+ .sync_single_for_device = arm_iommu_sync_single_for_device,
+
+ .map_sg = arm_iommu_map_sg,
+ .unmap_sg = arm_iommu_unmap_sg,
+ .sync_sg_for_cpu = arm_iommu_sync_sg_for_cpu,
+ .sync_sg_for_device = arm_iommu_sync_sg_for_device,
+};
+
+/**
+ * arm_iommu_create_mapping
+ * @bus: pointer to the bus holding the client device (for IOMMU calls)
+ * @base: start address of the valid IO address space
+ * @size: size of the valid IO address space
+ * @order: accuracy of the IO addresses allocations
+ *
+ * Creates a mapping structure which holds information about used/unused
+ * IO address ranges, which is required to perform memory allocation and
+ * mapping with IOMMU aware functions.
+ *
+ * The client device need to be attached to the mapping with
+ * arm_iommu_attach_device function.
+ */
+struct dma_iommu_mapping *
+arm_iommu_create_mapping(struct bus_type *bus, dma_addr_t base, size_t size,
+ int order)
+{
+ unsigned int count = size >> (PAGE_SHIFT + order);
+ unsigned int bitmap_size = BITS_TO_LONGS(count) * sizeof(long);
+ struct dma_iommu_mapping *mapping;
+ int err = -ENOMEM;
+
+ if (!count)
+ return ERR_PTR(-EINVAL);
+
+ mapping = kzalloc(sizeof(struct dma_iommu_mapping), GFP_KERNEL);
+ if (!mapping)
+ goto err;
+
+ mapping->bitmap = kzalloc(bitmap_size, GFP_KERNEL);
+ if (!mapping->bitmap)
+ goto err2;
+
+ mapping->base = base;
+ mapping->bits = BITS_PER_BYTE * bitmap_size;
+ mapping->order = order;
+ spin_lock_init(&mapping->lock);
+
+ mapping->domain = iommu_domain_alloc(bus);
+ if (!mapping->domain)
+ goto err3;
+
+ kref_init(&mapping->kref);
+ return mapping;
+err3:
+ kfree(mapping->bitmap);
+err2:
+ kfree(mapping);
+err:
+ return ERR_PTR(err);
+}
+
+static void release_iommu_mapping(struct kref *kref)
+{
+ struct dma_iommu_mapping *mapping =
+ container_of(kref, struct dma_iommu_mapping, kref);
+
+ iommu_domain_free(mapping->domain);
+ kfree(mapping->bitmap);
+ kfree(mapping);
+}
+
+void arm_iommu_release_mapping(struct dma_iommu_mapping *mapping)
+{
+ if (mapping)
+ kref_put(&mapping->kref, release_iommu_mapping);
+}
+
+/**
+ * arm_iommu_attach_device
+ * @dev: valid struct device pointer
+ * @mapping: io address space mapping structure (returned from
+ * arm_iommu_create_mapping)
+ *
+ * Attaches specified io address space mapping to the provided device,
+ * this replaces the dma operations (dma_map_ops pointer) with the
+ * IOMMU aware version. More than one client might be attached to
+ * the same io address space mapping.
+ */
+int arm_iommu_attach_device(struct device *dev,
+ struct dma_iommu_mapping *mapping)
+{
+ int err;
+
+ err = iommu_attach_device(mapping->domain, dev);
+ if (err)
+ return err;
+
+ kref_get(&mapping->kref);
+ dev->archdata.mapping = mapping;
+ set_dma_ops(dev, &iommu_ops);
+
+ pr_info("Attached IOMMU controller to %s device.\n", dev_name(dev));
+ return 0;
+}
+
+#endif