diff options
| -rw-r--r-- | arch/arm/mm/consistent.c | 53 | ||||
| -rw-r--r-- | include/asm-arm/memory.h | 9 |
2 files changed, 50 insertions, 12 deletions
diff --git a/arch/arm/mm/consistent.c b/arch/arm/mm/consistent.c index 0513ed1b2fc..c2ee18d2075 100644 --- a/arch/arm/mm/consistent.c +++ b/arch/arm/mm/consistent.c @@ -20,15 +20,25 @@ #include <asm/cacheflush.h> #include <asm/tlbflush.h> +#include <asm/sizes.h> + +/* Sanity check size */ +#if (CONSISTENT_DMA_SIZE % SZ_2M) +#error "CONSISTENT_DMA_SIZE must be multiple of 2MiB" +#endif -#define CONSISTENT_BASE (0xffc00000) #define CONSISTENT_END (0xffe00000) +#define CONSISTENT_BASE (CONSISTENT_END - CONSISTENT_DMA_SIZE) + #define CONSISTENT_OFFSET(x) (((unsigned long)(x) - CONSISTENT_BASE) >> PAGE_SHIFT) +#define CONSISTENT_PTE_INDEX(x) (((unsigned long)(x) - CONSISTENT_BASE) >> PGDIR_SHIFT) +#define NUM_CONSISTENT_PTES (CONSISTENT_DMA_SIZE >> PGDIR_SHIFT) + /* - * This is the page table (2MB) covering uncached, DMA consistent allocations + * These are the page tables (2MB each) covering uncached, DMA consistent allocations */ -static pte_t *consistent_pte; +static pte_t *consistent_pte[NUM_CONSISTENT_PTES]; static DEFINE_SPINLOCK(consistent_lock); /* @@ -142,7 +152,7 @@ __dma_alloc(struct device *dev, size_t size, dma_addr_t *handle, gfp_t gfp, unsigned long order; u64 mask = ISA_DMA_THRESHOLD, limit; - if (!consistent_pte) { + if (!consistent_pte[0]) { printk(KERN_ERR "%s: not initialised\n", __func__); dump_stack(); return NULL; @@ -205,9 +215,12 @@ __dma_alloc(struct device *dev, size_t size, dma_addr_t *handle, gfp_t gfp, c = vm_region_alloc(&consistent_head, size, gfp & ~(__GFP_DMA | __GFP_HIGHMEM)); if (c) { - pte_t *pte = consistent_pte + CONSISTENT_OFFSET(c->vm_start); + pte_t *pte; struct page *end = page + (1 << order); + int idx = CONSISTENT_PTE_INDEX(c->vm_start); + u32 off = CONSISTENT_OFFSET(c->vm_start) & (PTRS_PER_PTE-1); + pte = consistent_pte[idx] + off; c->vm_pages = page; /* @@ -226,6 +239,11 @@ __dma_alloc(struct device *dev, size_t size, dma_addr_t *handle, gfp_t gfp, set_pte(pte, mk_pte(page, prot)); page++; pte++; + off++; + if (off >= PTRS_PER_PTE) { + off = 0; + pte = consistent_pte[++idx]; + } } while (size -= PAGE_SIZE); /* @@ -327,6 +345,8 @@ void dma_free_coherent(struct device *dev, size_t size, void *cpu_addr, dma_addr struct vm_region *c; unsigned long flags, addr; pte_t *ptep; + int idx; + u32 off; WARN_ON(irqs_disabled()); @@ -347,7 +367,9 @@ void dma_free_coherent(struct device *dev, size_t size, void *cpu_addr, dma_addr size = c->vm_end - c->vm_start; } - ptep = consistent_pte + CONSISTENT_OFFSET(c->vm_start); + idx = CONSISTENT_PTE_INDEX(c->vm_start); + off = CONSISTENT_OFFSET(c->vm_start) & (PTRS_PER_PTE-1); + ptep = consistent_pte[idx] + off; addr = c->vm_start; do { pte_t pte = ptep_get_and_clear(&init_mm, addr, ptep); @@ -355,6 +377,11 @@ void dma_free_coherent(struct device *dev, size_t size, void *cpu_addr, dma_addr ptep++; addr += PAGE_SIZE; + off++; + if (off >= PTRS_PER_PTE) { + off = 0; + ptep = consistent_pte[++idx]; + } if (!pte_none(pte) && pte_present(pte)) { pfn = pte_pfn(pte); @@ -401,11 +428,12 @@ static int __init consistent_init(void) pgd_t *pgd; pmd_t *pmd; pte_t *pte; - int ret = 0; + int ret = 0, i = 0; + u32 base = CONSISTENT_BASE; do { - pgd = pgd_offset(&init_mm, CONSISTENT_BASE); - pmd = pmd_alloc(&init_mm, pgd, CONSISTENT_BASE); + pgd = pgd_offset(&init_mm, base); + pmd = pmd_alloc(&init_mm, pgd, base); if (!pmd) { printk(KERN_ERR "%s: no pmd tables\n", __func__); ret = -ENOMEM; @@ -413,15 +441,16 @@ static int __init consistent_init(void) } WARN_ON(!pmd_none(*pmd)); - pte = pte_alloc_kernel(pmd, CONSISTENT_BASE); + pte = pte_alloc_kernel(pmd, base); if (!pte) { printk(KERN_ERR "%s: no pte tables\n", __func__); ret = -ENOMEM; break; } - consistent_pte = pte; - } while (0); + consistent_pte[i++] = pte; + base += (1 << PGDIR_SHIFT); + } while (base < CONSISTENT_END); return ret; } diff --git a/include/asm-arm/memory.h b/include/asm-arm/memory.h index 3d7f08bd903..b4e1146ab68 100644 --- a/include/asm-arm/memory.h +++ b/include/asm-arm/memory.h @@ -25,6 +25,7 @@ #include <linux/config.h> #include <linux/compiler.h> #include <asm/arch/memory.h> +#include <asm/sizes.h> #ifndef TASK_SIZE /* @@ -48,6 +49,14 @@ #endif /* + * Size of DMA-consistent memory region. Must be multiple of 2M, + * between 2MB and 14MB inclusive. + */ +#ifndef CONSISTENT_DMA_SIZE +#define CONSISTENT_DMA_SIZE SZ_2M +#endif + +/* * Physical vs virtual RAM address space conversion. These are * private definitions which should NOT be used outside memory.h * files. Use virt_to_phys/phys_to_virt/__pa/__va instead. |