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nommu: Add noMMU support to the DMA API

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Signed-off-by: Catalin Marinas <catalin.marinas@arm.com>
This commit is contained in:
Catalin Marinas 2009-07-24 12:35:02 +01:00
parent 2732f4b6f1
commit ab6494f0c9
1 changed files with 72 additions and 22 deletions
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92
arch/arm/mm/dma-mapping.c
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@ -36,7 +36,34 @@
#define CONSISTENT_PTE_INDEX(x) (((unsigned long)(x) - CONSISTENT_BASE) >> PGDIR_SHIFT)
#define NUM_CONSISTENT_PTES (CONSISTENT_DMA_SIZE >> PGDIR_SHIFT)
static u64 get_coherent_dma_mask(struct device *dev)
{
u64 mask = ISA_DMA_THRESHOLD;
if (dev) {
mask = dev->coherent_dma_mask;
/*
* Sanity check the DMA mask - it must be non-zero, and
* must be able to be satisfied by a DMA allocation.
*/
if (mask == 0) {
dev_warn(dev, "coherent DMA mask is unset\n");
return 0;
}
if ((~mask) & ISA_DMA_THRESHOLD) {
dev_warn(dev, "coherent DMA mask %#llx is smaller "
"than system GFP_DMA mask %#llx\n",
mask, (unsigned long long)ISA_DMA_THRESHOLD);
return 0;
}
}
return mask;
}
#ifdef CONFIG_MMU
/*
* These are the page tables (2MB each) covering uncached, DMA consistent allocations
*/
@ -152,7 +179,8 @@ __dma_alloc(struct device *dev, size_t size, dma_addr_t *handle, gfp_t gfp,
struct page *page;
struct arm_vm_region *c;
unsigned long order;
u64 mask = ISA_DMA_THRESHOLD, limit;
u64 mask = get_coherent_dma_mask(dev);
u64 limit;
if (!consistent_pte[0]) {
printk(KERN_ERR "%s: not initialised\n", __func__);
@ -160,25 +188,8 @@ __dma_alloc(struct device *dev, size_t size, dma_addr_t *handle, gfp_t gfp,
return NULL;
}
if (dev) {
mask = dev->coherent_dma_mask;
/*
* Sanity check the DMA mask - it must be non-zero, and
* must be able to be satisfied by a DMA allocation.
*/
if (mask == 0) {
dev_warn(dev, "coherent DMA mask is unset\n");
if (!mask)
goto no_page;
}
if ((~mask) & ISA_DMA_THRESHOLD) {
dev_warn(dev, "coherent DMA mask %#llx is smaller "
"than system GFP_DMA mask %#llx\n",
mask, (unsigned long long)ISA_DMA_THRESHOLD);
goto no_page;
}
}
/*
* Sanity check the allocation size.
@ -267,6 +278,31 @@ __dma_alloc(struct device *dev, size_t size, dma_addr_t *handle, gfp_t gfp,
*handle = ~0;
return NULL;
}
#else /* !CONFIG_MMU */
static void *
__dma_alloc(struct device *dev, size_t size, dma_addr_t *handle, gfp_t gfp,
pgprot_t prot)
{
void *virt;
u64 mask = get_coherent_dma_mask(dev);
if (!mask)
goto error;
if (mask != 0xffffffff)
gfp |= GFP_DMA;
virt = kmalloc(size, gfp);
if (!virt)
goto error;
*handle = virt_to_dma(dev, virt);
return virt;
error:
*handle = ~0;
return NULL;
}
#endif /* CONFIG_MMU */
/*
* Allocate DMA-coherent memory space and return both the kernel remapped
@ -311,9 +347,10 @@ 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 ret = -ENXIO;
#ifdef CONFIG_MMU
unsigned long flags, user_size, kern_size;
struct arm_vm_region *c;
int ret = -ENXIO;
user_size = (vma->vm_end - vma->vm_start) >> PAGE_SHIFT;
@ -334,6 +371,7 @@ static int dma_mmap(struct device *dev, struct vm_area_struct *vma,
vma->vm_page_prot);
}
}
#endif /* CONFIG_MMU */
return ret;
}
@ -358,6 +396,7 @@ EXPORT_SYMBOL(dma_mmap_writecombine);
* free a page as defined by the above mapping.
* Must not be called with IRQs disabled.
*/
#ifdef CONFIG_MMU
void dma_free_coherent(struct device *dev, size_t size, void *cpu_addr, dma_addr_t handle)
{
struct arm_vm_region *c;
@ -444,6 +483,14 @@ void dma_free_coherent(struct device *dev, size_t size, void *cpu_addr, dma_addr
__func__, cpu_addr);
dump_stack();
}
#else /* !CONFIG_MMU */
void dma_free_coherent(struct device *dev, size_t size, void *cpu_addr, dma_addr_t handle)
{
if (dma_release_from_coherent(dev, get_order(size), cpu_addr))
return;
kfree(cpu_addr);
}
#endif /* CONFIG_MMU */
EXPORT_SYMBOL(dma_free_coherent);
/*
@ -451,10 +498,12 @@ EXPORT_SYMBOL(dma_free_coherent);
*/
static int __init consistent_init(void)
{
int ret = 0;
#ifdef CONFIG_MMU
pgd_t *pgd;
pmd_t *pmd;
pte_t *pte;
int ret = 0, i = 0;
int i = 0;
u32 base = CONSISTENT_BASE;
do {
@ -477,6 +526,7 @@ static int __init consistent_init(void)
consistent_pte[i++] = pte;
base += (1 << PGDIR_SHIFT);
} while (base < CONSISTENT_END);
#endif /* !CONFIG_MMU */
return ret;
}