diff --git a/arch/arm/include/asm/pgtable.h b/arch/arm/include/asm/pgtable.h index 201ccaa11f61..11397687f42c 100644 --- a/arch/arm/include/asm/pgtable.h +++ b/arch/arm/include/asm/pgtable.h @@ -304,13 +304,23 @@ PTE_BIT_FUNC(mkyoung, |= L_PTE_YOUNG); static inline pte_t pte_mkspecial(pte_t pte) { return pte; } +#define __pgprot_modify(prot,mask,bits) \ + __pgprot((pgprot_val(prot) & ~(mask)) | (bits)) + /* * Mark the prot value as uncacheable and unbufferable. */ #define pgprot_noncached(prot) \ - __pgprot((pgprot_val(prot) & ~L_PTE_MT_MASK) | L_PTE_MT_UNCACHED) + __pgprot_modify(prot, L_PTE_MT_MASK, L_PTE_MT_UNCACHED) #define pgprot_writecombine(prot) \ - __pgprot((pgprot_val(prot) & ~L_PTE_MT_MASK) | L_PTE_MT_BUFFERABLE) + __pgprot_modify(prot, L_PTE_MT_MASK, L_PTE_MT_BUFFERABLE) +#if __LINUX_ARM_ARCH__ >= 7 +#define pgprot_dmacoherent(prot) \ + __pgprot_modify(prot, L_PTE_MT_MASK|L_PTE_EXEC, L_PTE_MT_BUFFERABLE) +#else +#define pgprot_dmacoherent(prot) \ + __pgprot_modify(prot, L_PTE_MT_MASK|L_PTE_EXEC, L_PTE_MT_UNCACHED) +#endif #define pmd_none(pmd) (!pmd_val(pmd)) #define pmd_present(pmd) (pmd_val(pmd)) diff --git a/arch/arm/include/asm/system.h b/arch/arm/include/asm/system.h index d65b2f5bf41f..058e7e90881d 100644 --- a/arch/arm/include/asm/system.h +++ b/arch/arm/include/asm/system.h @@ -138,21 +138,26 @@ extern unsigned int user_debug; #define dmb() __asm__ __volatile__ ("" : : : "memory") #endif -#ifndef CONFIG_SMP +#if __LINUX_ARM_ARCH__ >= 7 || defined(CONFIG_SMP) +#define mb() dmb() +#define rmb() dmb() +#define wmb() dmb() +#else #define mb() do { if (arch_is_coherent()) dmb(); else barrier(); } while (0) #define rmb() do { if (arch_is_coherent()) dmb(); else barrier(); } while (0) #define wmb() do { if (arch_is_coherent()) dmb(); else barrier(); } while (0) +#endif + +#ifndef CONFIG_SMP #define smp_mb() barrier() #define smp_rmb() barrier() #define smp_wmb() barrier() #else -#define mb() dmb() -#define rmb() dmb() -#define wmb() dmb() -#define smp_mb() dmb() -#define smp_rmb() dmb() -#define smp_wmb() dmb() +#define smp_mb() mb() +#define smp_rmb() rmb() +#define smp_wmb() wmb() #endif + #define read_barrier_depends() do { } while(0) #define smp_read_barrier_depends() do { } while(0) diff --git a/arch/arm/mm/Makefile b/arch/arm/mm/Makefile index 055cb2aa8134..42352e75742b 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 b9590a7085ca..26325cb5d368 100644 --- a/arch/arm/mm/dma-mapping.c +++ b/arch/arm/mm/dma-mapping.c @@ -63,435 +63,86 @@ 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); - -/* - * 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; -}; - -static struct arm_vm_region consistent_head = { - .vm_list = LIST_HEAD_INIT(consistent_head.vm_list), - .vm_start = CONSISTENT_BASE, - .vm_end = CONSISTENT_END, -}; - -static struct arm_vm_region * -arm_vm_region_alloc(struct arm_vm_region *head, size_t size, gfp_t gfp) +static struct page *__dma_alloc_buffer(struct device *dev, 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; - } - - 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(&consistent_lock, flags); - return new; - - nospc: - spin_unlock_irqrestore(&consistent_lock, flags); - kfree(new); - out: - return NULL; -} - -static struct arm_vm_region *arm_vm_region_find(struct arm_vm_region *head, unsigned long addr) -{ - 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; - } - c = NULL; - out: - return c; -} - -#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) -{ - struct page *page; - struct arm_vm_region *c; - unsigned long order; + unsigned long order = get_order(size); + struct page *page, *p, *e; + void *ptr; u64 mask = get_coherent_dma_mask(dev); - u64 limit; - if (!consistent_pte[0]) { - printk(KERN_ERR "%s: not initialised\n", __func__); - dump_stack(); +#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 if (!mask) - goto no_page; - - /* - * 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; - } - - order = get_order(size); + return NULL; if (mask < 0xffffffffULL) gfp |= GFP_DMA; page = alloc_pages(gfp, order); if (!page) - goto no_page; + return NULL; /* - * Invalidate any data that might be lurking in the - * kernel direct-mapped region for device DMA. + * Now split the huge page and free the excess pages */ - { - void *ptr = page_address(page); - memset(ptr, 0, size); - dmac_flush_range(ptr, ptr + size); - outer_flush_range(__pa(ptr), __pa(ptr) + size); - } + split_page(page, order); + for (p = page + (size >> PAGE_SHIFT), e = page + (1 << order); p < e; p++) + __free_page(p); /* - * Allocate a virtual address in the consistent mapping region. + * Ensure that the allocated pages are zeroed, and that any data + * lurking in the kernel direct-mapped region is invalidated. */ - c = arm_vm_region_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); + ptr = page_address(page); + memset(ptr, 0, size); + dmac_flush_range(ptr, ptr + size); + outer_flush_range(__pa(ptr), __pa(ptr) + size); - 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++; - off++; - if (off >= PTRS_PER_PTE) { - off = 0; - pte = consistent_pte[++idx]; - } - } 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; + return page; } -#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 < 0xffffffffULL) - 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 - * virtual and bus address for that space. + * Free a DMA buffer. 'size' must be page aligned. */ -void * -dma_alloc_coherent(struct device *dev, size_t size, dma_addr_t *handle, gfp_t gfp) +static void __dma_free_buffer(struct page *page, size_t size) { - void *memory; + struct page *e = page + (size >> PAGE_SHIFT); - 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; + while (page < e) { + __free_page(page); + page++; } - - return __dma_alloc(dev, size, handle, gfp, - pgprot_noncached(pgprot_kernel)); } -EXPORT_SYMBOL(dma_alloc_coherent); -/* - * Allocate a writecombining region, in much the same way as - * dma_alloc_coherent above. - */ -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)); -} -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; - - 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); - - if (c) { - unsigned long off = vma->vm_pgoff; - - kern_size = (c->vm_end - c->vm_start) >> PAGE_SHIFT; - - if (off < kern_size && - user_size <= (kern_size - off)) { - ret = remap_pfn_range(vma, vma->vm_start, - page_to_pfn(c->vm_pages) + off, - user_size << PAGE_SHIFT, - vma->vm_page_prot); - } - } -#endif /* CONFIG_MMU */ - - 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_noncached(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 page as defined by the above mapping. - * Must not be called with IRQs disabled. + * These are the page tables (2MB each) covering uncached, DMA consistent allocations */ -#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; +static pte_t *consistent_pte[NUM_CONSISTENT_PTES]; - WARN_ON(irqs_disabled()); +#include "vmregion.h" - if (dma_release_from_coherent(dev, get_order(size), cpu_addr)) - return; +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, +}; - 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; - - 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(); -} -#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); +#ifdef CONFIG_HUGETLB_PAGE +#error ARM Coherent DMA allocator does not (yet) support huge TLB +#endif /* * Initialise the consistent memory allocation. @@ -499,7 +150,6 @@ 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; @@ -526,13 +176,228 @@ static int __init consistent_init(void) consistent_pte[i++] = pte; base += (1 << PGDIR_SHIFT); } while (base < CONSISTENT_END); -#endif /* !CONFIG_MMU */ return ret; } core_initcall(consistent_init); +static void * +__dma_alloc_remap(struct page *page, size_t size, gfp_t gfp, pgprot_t prot) +{ + struct arm_vmregion *c; + + 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_vmregion_alloc(&consistent_head, size, + gfp & ~(__GFP_DMA | __GFP_HIGHMEM)); + 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); + + return (void *)c->vm_start; + } + 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) +{ + struct page *page; + void *addr; + + *handle = ~0; + size = PAGE_ALIGN(size); + + page = __dma_alloc_buffer(dev, size, gfp); + if (!page) + return NULL; + + if (!arch_is_coherent()) + addr = __dma_alloc_remap(page, size, gfp, prot); + else + addr = page_address(page); + + if (addr) + *handle = page_to_dma(dev, page); + + return addr; +} + +/* + * 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 *memory; + + if (dma_alloc_from_coherent(dev, size, handle, &memory)) + return memory; + + return __dma_alloc(dev, size, handle, gfp, + pgprot_dmacoherent(pgprot_kernel)); +} +EXPORT_SYMBOL(dma_alloc_coherent); + +/* + * Allocate a writecombining region, in much the same way as + * dma_alloc_coherent above. + */ +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)); +} +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 user_size, kern_size; + struct arm_vmregion *c; + + user_size = (vma->vm_end - vma->vm_start) >> PAGE_SHIFT; + + c = arm_vmregion_find(&consistent_head, (unsigned long)cpu_addr); + if (c) { + unsigned long off = vma->vm_pgoff; + + kern_size = (c->vm_end - c->vm_start) >> PAGE_SHIFT; + + if (off < kern_size && + user_size <= (kern_size - off)) { + ret = remap_pfn_range(vma, vma->vm_start, + page_to_pfn(c->vm_pages) + off, + user_size << PAGE_SHIFT, + vma->vm_page_prot); + } + } +#endif /* CONFIG_MMU */ + + 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 page as defined by the above mapping. + * Must not be called with IRQs disabled. + */ +void dma_free_coherent(struct device *dev, size_t size, void *cpu_addr, dma_addr_t handle) +{ + WARN_ON(irqs_disabled()); + + if (dma_release_from_coherent(dev, get_order(size), cpu_addr)) + return; + + size = PAGE_ALIGN(size); + + if (!arch_is_coherent()) + __dma_free_remap(cpu_addr, size); + + __dma_free_buffer(dma_to_page(dev, handle), size); +} +EXPORT_SYMBOL(dma_free_coherent); + /* * Make an area consistent for devices. * Note: Drivers should NOT use this function directly, as it will break diff --git a/arch/arm/mm/vmregion.c b/arch/arm/mm/vmregion.c new file mode 100644 index 000000000000..19e09bdb1b8a --- /dev/null +++ b/arch/arm/mm/vmregion.c @@ -0,0 +1,131 @@ +#include +#include +#include + +#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 000000000000..6b2cdbdf3a85 --- /dev/null +++ b/arch/arm/mm/vmregion.h @@ -0,0 +1,29 @@ +#ifndef VMREGION_H +#define VMREGION_H + +#include +#include + +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