diff options
author | Russell King <rmk+kernel@arm.linux.org.uk> | 2009-12-04 15:00:00 +0000 |
---|---|---|
committer | Russell King <rmk+kernel@arm.linux.org.uk> | 2009-12-04 15:00:00 +0000 |
commit | c6baa1963c2a76ffdb157e8b9a5a55b30046b125 (patch) | |
tree | 9063398d2406042670759e207d9058ec5e7b770b /arch/arm/mm | |
parent | 5cb2faa6ede7ada9cb2bffc832c4ce60f53d6834 (diff) | |
parent | 26a26d329688ab018e068b412b03d43d7c299f0a (diff) | |
download | op-kernel-dev-c6baa1963c2a76ffdb157e8b9a5a55b30046b125.zip op-kernel-dev-c6baa1963c2a76ffdb157e8b9a5a55b30046b125.tar.gz |
Merge branch 'pending-dma-coherent' into devel
Diffstat (limited to 'arch/arm/mm')
-rw-r--r-- | arch/arm/mm/Makefile | 2 | ||||
-rw-r--r-- | arch/arm/mm/dma-mapping.c | 497 | ||||
-rw-r--r-- | arch/arm/mm/vmregion.c | 131 | ||||
-rw-r--r-- | arch/arm/mm/vmregion.h | 29 |
4 files changed, 342 insertions, 317 deletions
diff --git a/arch/arm/mm/Makefile b/arch/arm/mm/Makefile index 055cb2aa..42352e7 100644 --- a/arch/arm/mm/Makefile +++ b/arch/arm/mm/Makefile @@ -6,7 +6,7 @@ obj-y := dma-mapping.o extable.o fault.o init.o \ iomap.o obj-$(CONFIG_MMU) += fault-armv.o flush.o ioremap.o mmap.o \ - pgd.o mmu.o + pgd.o mmu.o vmregion.o ifneq ($(CONFIG_MMU),y) obj-y += nommu.o diff --git a/arch/arm/mm/dma-mapping.c b/arch/arm/mm/dma-mapping.c index b9590a7..26325cb 100644 --- a/arch/arm/mm/dma-mapping.c +++ b/arch/arm/mm/dma-mapping.c @@ -63,194 +63,152 @@ static u64 get_coherent_dma_mask(struct device *dev) return mask; } -#ifdef CONFIG_MMU /* - * These are the page tables (2MB each) covering uncached, DMA consistent allocations + * Allocate a DMA buffer for 'dev' of size 'size' using the + * specified gfp mask. Note that 'size' must be page aligned. */ -static pte_t *consistent_pte[NUM_CONSISTENT_PTES]; -static DEFINE_SPINLOCK(consistent_lock); +static struct page *__dma_alloc_buffer(struct device *dev, size_t size, gfp_t gfp) +{ + unsigned long order = get_order(size); + struct page *page, *p, *e; + void *ptr; + u64 mask = get_coherent_dma_mask(dev); -/* - * VM region handling support. - * - * This should become something generic, handling VM region allocations for - * vmalloc and similar (ioremap, module space, etc). - * - * I envisage vmalloc()'s supporting vm_struct becoming: - * - * struct vm_struct { - * struct vm_region region; - * unsigned long flags; - * struct page **pages; - * unsigned int nr_pages; - * unsigned long phys_addr; - * }; - * - * get_vm_area() would then call vm_region_alloc with an appropriate - * struct vm_region head (eg): - * - * struct vm_region vmalloc_head = { - * .vm_list = LIST_HEAD_INIT(vmalloc_head.vm_list), - * .vm_start = VMALLOC_START, - * .vm_end = VMALLOC_END, - * }; - * - * However, vmalloc_head.vm_start is variable (typically, it is dependent on - * the amount of RAM found at boot time.) I would imagine that get_vm_area() - * would have to initialise this each time prior to calling vm_region_alloc(). - */ -struct arm_vm_region { - struct list_head vm_list; - unsigned long vm_start; - unsigned long vm_end; - struct page *vm_pages; - int vm_active; -}; +#ifdef CONFIG_DMA_API_DEBUG + u64 limit = (mask + 1) & ~mask; + if (limit && size >= limit) { + dev_warn(dev, "coherent allocation too big (requested %#x mask %#llx)\n", + size, mask); + return NULL; + } +#endif -static struct arm_vm_region consistent_head = { - .vm_list = LIST_HEAD_INIT(consistent_head.vm_list), - .vm_start = CONSISTENT_BASE, - .vm_end = CONSISTENT_END, -}; + if (!mask) + return NULL; -static struct arm_vm_region * -arm_vm_region_alloc(struct arm_vm_region *head, size_t size, gfp_t gfp) -{ - unsigned long addr = head->vm_start, end = head->vm_end - size; - unsigned long flags; - struct arm_vm_region *c, *new; - - new = kmalloc(sizeof(struct arm_vm_region), gfp); - if (!new) - goto out; - - spin_lock_irqsave(&consistent_lock, flags); - - list_for_each_entry(c, &head->vm_list, vm_list) { - if ((addr + size) < addr) - goto nospc; - if ((addr + size) <= c->vm_start) - goto found; - addr = c->vm_end; - if (addr > end) - goto nospc; - } + if (mask < 0xffffffffULL) + gfp |= GFP_DMA; + + page = alloc_pages(gfp, order); + if (!page) + return NULL; - found: /* - * Insert this entry _before_ the one we found. + * Now split the huge page and free the excess pages */ - list_add_tail(&new->vm_list, &c->vm_list); - new->vm_start = addr; - new->vm_end = addr + size; - new->vm_active = 1; - - spin_unlock_irqrestore(&consistent_lock, flags); - return new; - - nospc: - spin_unlock_irqrestore(&consistent_lock, flags); - kfree(new); - out: - return NULL; + split_page(page, order); + for (p = page + (size >> PAGE_SHIFT), e = page + (1 << order); p < e; p++) + __free_page(p); + + /* + * Ensure that the allocated pages are zeroed, and that any data + * 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); + + return page; } -static struct arm_vm_region *arm_vm_region_find(struct arm_vm_region *head, unsigned long addr) +/* + * Free a DMA buffer. 'size' must be page aligned. + */ +static void __dma_free_buffer(struct page *page, size_t size) { - struct arm_vm_region *c; - - list_for_each_entry(c, &head->vm_list, vm_list) { - if (c->vm_active && c->vm_start == addr) - goto out; + struct page *e = page + (size >> PAGE_SHIFT); + + while (page < e) { + __free_page(page); + page++; } - c = NULL; - out: - return c; } +#ifdef CONFIG_MMU +/* + * These are the page tables (2MB each) covering uncached, DMA consistent allocations + */ +static pte_t *consistent_pte[NUM_CONSISTENT_PTES]; + +#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_start = CONSISTENT_BASE, + .vm_end = CONSISTENT_END, +}; + #ifdef CONFIG_HUGETLB_PAGE #error ARM Coherent DMA allocator does not (yet) support huge TLB #endif -static void * -__dma_alloc(struct device *dev, size_t size, dma_addr_t *handle, gfp_t gfp, - pgprot_t prot) +/* + * Initialise the consistent memory allocation. + */ +static int __init consistent_init(void) { - struct page *page; - struct arm_vm_region *c; - unsigned long order; - u64 mask = get_coherent_dma_mask(dev); - u64 limit; + int ret = 0; + pgd_t *pgd; + pmd_t *pmd; + pte_t *pte; + int i = 0; + u32 base = CONSISTENT_BASE; - if (!consistent_pte[0]) { - printk(KERN_ERR "%s: not initialised\n", __func__); - dump_stack(); - return NULL; - } + do { + 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; + break; + } + WARN_ON(!pmd_none(*pmd)); - if (!mask) - goto no_page; + pte = pte_alloc_kernel(pmd, base); + if (!pte) { + printk(KERN_ERR "%s: no pte tables\n", __func__); + ret = -ENOMEM; + break; + } - /* - * Sanity check the allocation size. - */ - size = PAGE_ALIGN(size); - limit = (mask + 1) & ~mask; - if ((limit && size >= limit) || - size >= (CONSISTENT_END - CONSISTENT_BASE)) { - printk(KERN_WARNING "coherent allocation too big " - "(requested %#x mask %#llx)\n", size, mask); - goto no_page; - } + consistent_pte[i++] = pte; + base += (1 << PGDIR_SHIFT); + } while (base < CONSISTENT_END); - order = get_order(size); + return ret; +} - if (mask < 0xffffffffULL) - gfp |= GFP_DMA; +core_initcall(consistent_init); - page = alloc_pages(gfp, order); - if (!page) - goto no_page; +static void * +__dma_alloc_remap(struct page *page, size_t size, gfp_t gfp, pgprot_t prot) +{ + struct arm_vmregion *c; - /* - * Invalidate any data that might be lurking in the - * kernel direct-mapped region for device DMA. - */ - { - void *ptr = page_address(page); - memset(ptr, 0, size); - dmac_flush_range(ptr, ptr + size); - outer_flush_range(__pa(ptr), __pa(ptr) + size); + if (!consistent_pte[0]) { + printk(KERN_ERR "%s: not initialised\n", __func__); + dump_stack(); + return NULL; } /* * Allocate a virtual address in the consistent mapping region. */ - c = arm_vm_region_alloc(&consistent_head, size, + c = arm_vmregion_alloc(&consistent_head, size, gfp & ~(__GFP_DMA | __GFP_HIGHMEM)); if (c) { 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; - split_page(page, order); - - /* - * Set the "dma handle" - */ - *handle = page_to_dma(dev, page); - do { BUG_ON(!pte_none(*pte)); - /* - * x86 does not mark the pages reserved... - */ - SetPageReserved(page); set_pte_ext(pte, mk_pte(page, prot), 0); page++; pte++; @@ -261,48 +219,90 @@ __dma_alloc(struct device *dev, size_t size, dma_addr_t *handle, gfp_t gfp, } } while (size -= PAGE_SIZE); - /* - * Free the otherwise unused pages. - */ - while (page < end) { - __free_page(page); - page++; - } - return (void *)c->vm_start; } - - if (page) - __free_pages(page, order); - no_page: - *handle = ~0; return NULL; } + +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; + + 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", + __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", + __func__, c->vm_end - c->vm_start, size); + dump_stack(); + size = c->vm_end - 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); + + 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); + + flush_tlb_kernel_range(c->vm_start, c->vm_end); + + arm_vmregion_free(&consistent_head, c); +} + #else /* !CONFIG_MMU */ + +#define __dma_alloc_remap(page, size, gfp, prot) page_address(page) +#define __dma_free_remap(addr, size) do { } while (0) + +#endif /* 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); + struct page *page; + void *addr; - if (!mask) - goto error; + *handle = ~0; + size = PAGE_ALIGN(size); - if (mask < 0xffffffffULL) - gfp |= GFP_DMA; - virt = kmalloc(size, gfp); - if (!virt) - goto error; + page = __dma_alloc_buffer(dev, size, gfp); + if (!page) + return NULL; - *handle = virt_to_dma(dev, virt); - return virt; + if (!arch_is_coherent()) + addr = __dma_alloc_remap(page, size, gfp, prot); + else + addr = page_address(page); -error: - *handle = ~0; - return NULL; + if (addr) + *handle = page_to_dma(dev, page); + + return addr; } -#endif /* CONFIG_MMU */ /* * Allocate DMA-coherent memory space and return both the kernel remapped @@ -316,19 +316,8 @@ dma_alloc_coherent(struct device *dev, size_t size, dma_addr_t *handle, gfp_t gf if (dma_alloc_from_coherent(dev, size, handle, &memory)) return memory; - if (arch_is_coherent()) { - void *virt; - - virt = kmalloc(size, gfp); - if (!virt) - return NULL; - *handle = virt_to_dma(dev, virt); - - return virt; - } - return __dma_alloc(dev, size, handle, gfp, - pgprot_noncached(pgprot_kernel)); + pgprot_dmacoherent(pgprot_kernel)); } EXPORT_SYMBOL(dma_alloc_coherent); @@ -349,15 +338,12 @@ static int dma_mmap(struct device *dev, struct vm_area_struct *vma, { int ret = -ENXIO; #ifdef CONFIG_MMU - unsigned long flags, user_size, kern_size; - struct arm_vm_region *c; + unsigned long user_size, kern_size; + struct arm_vmregion *c; user_size = (vma->vm_end - vma->vm_start) >> PAGE_SHIFT; - spin_lock_irqsave(&consistent_lock, flags); - c = arm_vm_region_find(&consistent_head, (unsigned long)cpu_addr); - spin_unlock_irqrestore(&consistent_lock, flags); - + c = arm_vmregion_find(&consistent_head, (unsigned long)cpu_addr); if (c) { unsigned long off = vma->vm_pgoff; @@ -379,7 +365,7 @@ static int dma_mmap(struct device *dev, struct vm_area_struct *vma, 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_noncached(vma->vm_page_prot); + 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); @@ -396,144 +382,23 @@ 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; - unsigned long flags, addr; - pte_t *ptep; - int idx; - u32 off; - WARN_ON(irqs_disabled()); if (dma_release_from_coherent(dev, get_order(size), cpu_addr)) return; - if (arch_is_coherent()) { - kfree(cpu_addr); - return; - } - size = PAGE_ALIGN(size); - spin_lock_irqsave(&consistent_lock, flags); - c = arm_vm_region_find(&consistent_head, (unsigned long)cpu_addr); - if (!c) - goto no_area; - - c->vm_active = 0; - spin_unlock_irqrestore(&consistent_lock, flags); - - if ((c->vm_end - c->vm_start) != size) { - printk(KERN_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; - } - - 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); - unsigned long pfn; - - 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); - - if (pfn_valid(pfn)) { - struct page *page = pfn_to_page(pfn); - - /* - * x86 does not mark the pages reserved... - */ - ClearPageReserved(page); - - __free_page(page); - continue; - } - } - - printk(KERN_CRIT "%s: bad page in kernel page table\n", - __func__); - } while (size -= PAGE_SIZE); - - flush_tlb_kernel_range(c->vm_start, c->vm_end); - - spin_lock_irqsave(&consistent_lock, flags); - list_del(&c->vm_list); - spin_unlock_irqrestore(&consistent_lock, flags); - - kfree(c); - return; + if (!arch_is_coherent()) + __dma_free_remap(cpu_addr, size); - no_area: - spin_unlock_irqrestore(&consistent_lock, flags); - printk(KERN_ERR "%s: trying to free invalid coherent area: %p\n", - __func__, cpu_addr); - dump_stack(); + __dma_free_buffer(dma_to_page(dev, handle), size); } -#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); /* - * Initialise the consistent memory allocation. - */ -static int __init consistent_init(void) -{ - int ret = 0; -#ifdef CONFIG_MMU - pgd_t *pgd; - pmd_t *pmd; - pte_t *pte; - int i = 0; - u32 base = CONSISTENT_BASE; - - do { - 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; - 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 += (1 << PGDIR_SHIFT); - } while (base < CONSISTENT_END); -#endif /* !CONFIG_MMU */ - - return ret; -} - -core_initcall(consistent_init); - -/* * Make an area consistent for devices. * Note: Drivers should NOT use this function directly, as it will break * platforms with CONFIG_DMABOUNCE. diff --git a/arch/arm/mm/vmregion.c b/arch/arm/mm/vmregion.c new file mode 100644 index 0000000..19e09bdb --- /dev/null +++ b/arch/arm/mm/vmregion.c @@ -0,0 +1,131 @@ +#include <linux/spinlock.h> +#include <linux/list.h> +#include <linux/slab.h> + +#include "vmregion.h" + +/* + * VM region handling support. + * + * This should become something generic, handling VM region allocations for + * vmalloc and similar (ioremap, module space, etc). + * + * I envisage vmalloc()'s supporting vm_struct becoming: + * + * struct vm_struct { + * struct vmregion region; + * unsigned long flags; + * struct page **pages; + * unsigned int nr_pages; + * unsigned long phys_addr; + * }; + * + * get_vm_area() would then call vmregion_alloc with an appropriate + * struct vmregion head (eg): + * + * struct vmregion vmalloc_head = { + * .vm_list = LIST_HEAD_INIT(vmalloc_head.vm_list), + * .vm_start = VMALLOC_START, + * .vm_end = VMALLOC_END, + * }; + * + * However, vmalloc_head.vm_start is variable (typically, it is dependent on + * the amount of RAM found at boot time.) I would imagine that get_vm_area() + * would have to initialise this each time prior to calling vmregion_alloc(). + */ + +struct arm_vmregion * +arm_vmregion_alloc(struct arm_vmregion_head *head, size_t size, gfp_t gfp) +{ + unsigned long addr = head->vm_start, end = head->vm_end - size; + unsigned long flags; + struct arm_vmregion *c, *new; + + if (head->vm_end - head->vm_start < size) { + printk(KERN_WARNING "%s: allocation too big (requested %#x)\n", + __func__, size); + goto out; + } + + new = kmalloc(sizeof(struct arm_vmregion), gfp); + if (!new) + goto out; + + spin_lock_irqsave(&head->vm_lock, flags); + + list_for_each_entry(c, &head->vm_list, vm_list) { + if ((addr + size) < addr) + goto nospc; + if ((addr + size) <= c->vm_start) + goto found; + addr = c->vm_end; + if (addr > end) + goto nospc; + } + + found: + /* + * Insert this entry _before_ the one we found. + */ + list_add_tail(&new->vm_list, &c->vm_list); + new->vm_start = addr; + new->vm_end = addr + size; + new->vm_active = 1; + + spin_unlock_irqrestore(&head->vm_lock, flags); + return new; + + nospc: + spin_unlock_irqrestore(&head->vm_lock, flags); + kfree(new); + out: + return NULL; +} + +static struct arm_vmregion *__arm_vmregion_find(struct arm_vmregion_head *head, unsigned long addr) +{ + struct arm_vmregion *c; + + list_for_each_entry(c, &head->vm_list, vm_list) { + if (c->vm_active && c->vm_start == addr) + goto out; + } + c = NULL; + out: + return c; +} + +struct arm_vmregion *arm_vmregion_find(struct arm_vmregion_head *head, unsigned long addr) +{ + struct arm_vmregion *c; + unsigned long flags; + + spin_lock_irqsave(&head->vm_lock, flags); + c = __arm_vmregion_find(head, addr); + spin_unlock_irqrestore(&head->vm_lock, flags); + return c; +} + +struct arm_vmregion *arm_vmregion_find_remove(struct arm_vmregion_head *head, unsigned long addr) +{ + struct arm_vmregion *c; + unsigned long flags; + + spin_lock_irqsave(&head->vm_lock, flags); + c = __arm_vmregion_find(head, addr); + if (c) + c->vm_active = 0; + spin_unlock_irqrestore(&head->vm_lock, flags); + return c; +} + +void arm_vmregion_free(struct arm_vmregion_head *head, struct arm_vmregion *c) +{ + unsigned long flags; + + spin_lock_irqsave(&head->vm_lock, flags); + list_del(&c->vm_list); + spin_unlock_irqrestore(&head->vm_lock, flags); + + kfree(c); +} diff --git a/arch/arm/mm/vmregion.h b/arch/arm/mm/vmregion.h new file mode 100644 index 0000000..6b2cdbd --- /dev/null +++ b/arch/arm/mm/vmregion.h @@ -0,0 +1,29 @@ +#ifndef VMREGION_H +#define VMREGION_H + +#include <linux/spinlock.h> +#include <linux/list.h> + +struct page; + +struct arm_vmregion_head { + spinlock_t vm_lock; + struct list_head vm_list; + unsigned long vm_start; + unsigned long vm_end; +}; + +struct arm_vmregion { + struct list_head vm_list; + unsigned long vm_start; + unsigned long vm_end; + struct page *vm_pages; + int vm_active; +}; + +struct arm_vmregion *arm_vmregion_alloc(struct arm_vmregion_head *, size_t, gfp_t); +struct arm_vmregion *arm_vmregion_find(struct arm_vmregion_head *, unsigned long); +struct arm_vmregion *arm_vmregion_find_remove(struct arm_vmregion_head *, unsigned long); +void arm_vmregion_free(struct arm_vmregion_head *, struct arm_vmregion *); + +#endif |