This patch changes dma-mapping subsystem to use generic vmalloc areas for all consistent dma allocations. This increases the total size limit of the consistent allocations and removes platform hacks and a lot of duplicated code.
Signed-off-by: Marek Szyprowski m.szyprowski@samsung.com Reviewed-by: Kyungmin Park kyungmin.park@samsung.com --- arch/arm/include/asm/dma-mapping.h | 2 +- arch/arm/mm/dma-mapping.c | 220 +++++++----------------------------- 2 files changed, 40 insertions(+), 182 deletions(-)
diff --git a/arch/arm/include/asm/dma-mapping.h b/arch/arm/include/asm/dma-mapping.h index cb3b7c9..92b0afb 100644 --- a/arch/arm/include/asm/dma-mapping.h +++ b/arch/arm/include/asm/dma-mapping.h @@ -210,7 +210,7 @@ int dma_mmap_writecombine(struct device *, struct vm_area_struct *, * DMA region above it's default value of 2MB. It must be called before the * memory allocator is initialised, i.e. before any core_initcall. */ -extern void __init init_consistent_dma_size(unsigned long size); +static inline void init_consistent_dma_size(unsigned long size) { }
#ifdef CONFIG_DMABOUNCE diff --git a/arch/arm/mm/dma-mapping.c b/arch/arm/mm/dma-mapping.c index db23ae4..74ff839 100644 --- a/arch/arm/mm/dma-mapping.c +++ b/arch/arm/mm/dma-mapping.c @@ -19,6 +19,8 @@ #include <linux/dma-mapping.h> #include <linux/highmem.h> #include <linux/slab.h> +#include <linux/vmalloc.h> +#include <linux/io.h>
#include <asm/memory.h> #include <asm/highmem.h> @@ -119,204 +121,59 @@ static void __dma_free_buffer(struct page *page, size_t size) }
#ifdef CONFIG_MMU - -#define CONSISTENT_OFFSET(x) (((unsigned long)(x) - consistent_base) >> PAGE_SHIFT) -#define CONSISTENT_PTE_INDEX(x) (((unsigned long)(x) - consistent_base) >> PMD_SHIFT) - -/* - * These are the page tables (2MB each) covering uncached, DMA consistent allocations - */ -static pte_t **consistent_pte; - -#define DEFAULT_CONSISTENT_DMA_SIZE SZ_2M - -unsigned long consistent_base = CONSISTENT_END - DEFAULT_CONSISTENT_DMA_SIZE; - -void __init init_consistent_dma_size(unsigned long size) -{ - unsigned long base = CONSISTENT_END - ALIGN(size, SZ_2M); - - BUG_ON(consistent_pte); /* Check we're called before DMA region init */ - BUG_ON(base < VMALLOC_END); - - /* Grow region to accommodate specified size */ - if (base < consistent_base) - consistent_base = base; -} - -#include "vmregion.h" - -static struct arm_vmregion_head consistent_head = { - .vm_lock = __SPIN_LOCK_UNLOCKED(&consistent_head.vm_lock), - .vm_list = LIST_HEAD_INIT(consistent_head.vm_list), - .vm_end = CONSISTENT_END, -}; - #ifdef CONFIG_HUGETLB_PAGE #error ARM Coherent DMA allocator does not (yet) support huge TLB #endif
-/* - * Initialise the consistent memory allocation. - */ -static int __init consistent_init(void) -{ - int ret = 0; - pgd_t *pgd; - pud_t *pud; - pmd_t *pmd; - pte_t *pte; - int i = 0; - unsigned long base = consistent_base; - unsigned long num_ptes = (CONSISTENT_END - base) >> PMD_SHIFT; - - consistent_pte = kmalloc(num_ptes * sizeof(pte_t), GFP_KERNEL); - if (!consistent_pte) { - pr_err("%s: no memory\n", __func__); - return -ENOMEM; - } - - pr_debug("DMA memory: 0x%08lx - 0x%08lx:\n", base, CONSISTENT_END); - consistent_head.vm_start = base; - - do { - pgd = pgd_offset(&init_mm, base); - - pud = pud_alloc(&init_mm, pgd, base); - if (!pud) { - printk(KERN_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__); - ret = -ENOMEM; - break; - } - WARN_ON(!pmd_none(*pmd)); - - pte = pte_alloc_kernel(pmd, base); - if (!pte) { - printk(KERN_ERR "%s: no pte tables\n", __func__); - ret = -ENOMEM; - break; - } - - consistent_pte[i++] = pte; - base += PMD_SIZE; - } while (base < CONSISTENT_END); - - return ret; -} - -core_initcall(consistent_init); - static void * __dma_alloc_remap(struct page *page, size_t size, gfp_t gfp, pgprot_t prot, const void *caller) { - struct arm_vmregion *c; - size_t align; - int bit; - - if (!consistent_pte) { - printk(KERN_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), caller); - if (c) { - pte_t *pte; - 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; - - do { - BUG_ON(!pte_none(*pte)); - - set_pte_ext(pte, mk_pte(page, prot), 0); - page++; - pte++; - off++; - if (off >= PTRS_PER_PTE) { - off = 0; - pte = consistent_pte[++idx]; - } - } while (size -= PAGE_SIZE); - - dsb(); + struct vm_struct *area; + unsigned long addr;
- return (void *)c->vm_start; - } - return NULL; + area = get_vm_area_caller(size, VM_DMA | VM_USERMAP, caller); + if (!area) + return NULL; + addr = (unsigned long)area->addr; + area->phys_addr = __pfn_to_phys(page_to_pfn(page)); + + if (ioremap_page_range(addr, addr + size, area->phys_addr, prot)) { + vunmap((void *)addr); + return NULL; + } + return (void *)addr; }
static void __dma_free_remap(void *cpu_addr, size_t size) { - struct arm_vmregion *c; - unsigned long addr; - pte_t *ptep; - int idx; - u32 off; + struct vm_struct *area; + + read_lock(&vmlist_lock);
- c = arm_vmregion_find_remove(&consistent_head, (unsigned long)cpu_addr); - if (!c) { + area = find_vm_area(cpu_addr); + if (!area) { printk(KERN_ERR "%s: trying to free invalid coherent area: %p\n", __func__, cpu_addr); dump_stack(); + read_unlock(&vmlist_lock); return; }
- if ((c->vm_end - c->vm_start) != size) { + /* + * get_vm_area_caller always use additional guard page, so skip it here + */ + if (area->size - PAGE_SIZE != size) { printk(KERN_ERR "%s: freeing wrong coherent size (%ld != %d)\n", - __func__, c->vm_end - c->vm_start, size); + __func__, area->size, size); dump_stack(); - size = c->vm_end - c->vm_start; + size = area->size; }
- 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); - - ptep++; - addr += PAGE_SIZE; - off++; - if (off >= PTRS_PER_PTE) { - off = 0; - ptep = consistent_pte[++idx]; - } - - if (pte_none(pte) || !pte_present(pte)) - printk(KERN_CRIT "%s: bad page in kernel page table\n", - __func__); - } while (size -= PAGE_SIZE); + unmap_kernel_range((unsigned long)cpu_addr, size); + read_unlock(&vmlist_lock);
- flush_tlb_kernel_range(c->vm_start, c->vm_end); - - arm_vmregion_free(&consistent_head, c); + vunmap(cpu_addr); }
#else /* !CONFIG_MMU */ @@ -398,25 +255,29 @@ static int dma_mmap(struct device *dev, struct vm_area_struct *vma, { int ret = -ENXIO; #ifdef CONFIG_MMU + struct vm_struct *area; unsigned long user_size, kern_size; - struct arm_vmregion *c;
+ read_lock(&vmlist_lock); + area = find_vm_area(cpu_addr); user_size = (vma->vm_end - vma->vm_start) >> PAGE_SHIFT;
- c = arm_vmregion_find(&consistent_head, (unsigned long)cpu_addr); - if (c) { + if (area) { unsigned long off = vma->vm_pgoff; + unsigned long phys = __phys_to_pfn(area->phys_addr);
- kern_size = (c->vm_end - c->vm_start) >> PAGE_SHIFT; + /* skip vmalloc guard page */ + kern_size = (area->size >> PAGE_SHIFT) - 1;
if (off < kern_size && user_size <= (kern_size - off)) { ret = remap_pfn_range(vma, vma->vm_start, - page_to_pfn(c->vm_pages) + off, + phys + off, user_size << PAGE_SHIFT, vma->vm_page_prot); } } + read_unlock(&vmlist_lock); #endif /* CONFIG_MMU */
return ret; @@ -726,9 +587,6 @@ EXPORT_SYMBOL(dma_set_mask);
static int __init dma_debug_do_init(void) { -#ifdef CONFIG_MMU - arm_vmregion_create_proc("dma-mappings", &consistent_head); -#endif dma_debug_init(PREALLOC_DMA_DEBUG_ENTRIES); return 0; }