Re: [Linaro-mm-sig] [PATCHv5 2/2] ARM: dma-mapping: remove custom consistent dma region

Hi Marek,

I looked at patch and have minor points and a question. I should have said in early patch. Sorry about that. Anyway, except below points, It's good to me.

On Fri, Jul 27, 2012 at 02:03:39PM +0200, Marek Szyprowski wrote:

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.

Atomic allocations are served from special pool preallocated on boot, becasue vmalloc areas cannot be reliably created in atomic context.

Signed-off-by: Marek Szyprowski m.szyprowski@samsung.com Reviewed-by: Kyungmin Park kyungmin.park@samsung.com

---

Documentation/kernel-parameters.txt | 2 +- arch/arm/include/asm/dma-mapping.h | 2 +- arch/arm/mm/dma-mapping.c | 511 +++++++++++++---------------------- arch/arm/mm/mm.h | 3 + include/linux/vmalloc.h | 1 + mm/vmalloc.c | 10 +- 6 files changed, 197 insertions(+), 332 deletions(-)

diff --git a/Documentation/kernel-parameters.txt b/Documentation/kernel-parameters.txt index a92c5eb..4ee28f3 100644 --- a/Documentation/kernel-parameters.txt +++ b/Documentation/kernel-parameters.txt @@ -526,7 +526,7 @@ bytes respectively. Such letter suffixes can also be entirely omitted. coherent_pool=nn[KMG] [ARM,KNL] Sets the size of memory pool for coherent, atomic dma

• 	allocations if Contiguous Memory Allocator (CMA) is used.
  

• 	allocations, by default set to 256K.
  

code_bytes [X86] How many bytes of object code to print in an oops report. diff --git a/arch/arm/include/asm/dma-mapping.h b/arch/arm/include/asm/dma-mapping.h index bbef15d..80777d87 100644 --- a/arch/arm/include/asm/dma-mapping.h +++ b/arch/arm/include/asm/dma-mapping.h @@ -226,7 +226,7 @@ static inline int dma_mmap_writecombine(struct device *dev, struct vm_area_struc

• 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) { } /*

• For SA-1111, IXP425, and ADI systems the dma-mapping functions are "magic"

diff --git a/arch/arm/mm/dma-mapping.c b/arch/arm/mm/dma-mapping.c index 655878b..4d750a6 100644 --- a/arch/arm/mm/dma-mapping.c +++ b/arch/arm/mm/dma-mapping.c @@ -22,6 +22,7 @@ #include <linux/memblock.h> #include <linux/slab.h> #include <linux/iommu.h> +#include <linux/io.h> #include <linux/vmalloc.h> #include <asm/memory.h> @@ -217,115 +218,70 @@ 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

-static 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;
• if (IS_ENABLED(CONFIG_CMA) && !IS_ENABLED(CONFIG_ARM_DMA_USE_IOMMU))

• return 0;
  

• 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) {
  

• 	pr_err("%s: no pud tables\n", __func__);
  

• 	ret = -ENOMEM;
  

• 	break;
  

• }
  

• pmd = pmd_alloc(&init_mm, pud, base);
  

• if (!pmd) {
  

• 	pr_err("%s: no pmd tables\n", __func__);
  

• 	ret = -ENOMEM;
  

• 	break;
  

• }
  

• WARN_ON(!pmd_none(*pmd));
  

• pte = pte_alloc_kernel(pmd, base);
  

• if (!pte) {
  

• 	pr_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 *__alloc_from_contiguous(struct device *dev, size_t size, pgprot_t prot, struct page **ret_page); -static struct arm_vmregion_head coherent_head = {

• .vm_lock = __SPIN_LOCK_UNLOCKED(&coherent_head.vm_lock),
• .vm_list = LIST_HEAD_INIT(coherent_head.vm_list),

+static void *__alloc_remap_buffer(struct device *dev, size_t size, gfp_t gfp,

• 		 pgprot_t prot, struct page **ret_page,
  

• 		 const void *caller);
  

+static void * +__dma_alloc_remap(struct page *page, size_t size, gfp_t gfp, pgprot_t prot,

• const void *caller)

+{

• struct vm_struct *area;
• unsigned long addr;
• /*

• * DMA allocation can be mapped to user space, so lets
  

• * set VM_USERMAP flags too.
  

• */
  

• area = get_vm_area_caller(size, VM_ARM_DMA_CONSISTENT | 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 vm_struct *area = find_vm_area(cpu_addr);
• if (!area || !(area->flags & (VM_ARM_DMA_CONSISTENT | VM_USERMAP))) {

It's not a exact check. You should check it by following as. (area->flags & (VM_ARM_DMA_CONSISTENT | VM_USERMAP)) != (VM_ARM_DMA_CONSISTENT | VM_USERMAP)

• WARN(1, "%s: trying to free invalid coherent area: %p\n",
  

•        __func__, cpu_addr);
  

We need __func__? WARN will show it on call stack.

• return;
  

• }
• unmap_kernel_range((unsigned long)cpu_addr, size);
• vunmap(cpu_addr);

+}

+struct dma_pool {

• size_t size;
• spinlock_t lock;
• unsigned long *bitmap;
• unsigned long nr_pages;
• void *vaddr;
• struct page *page;

}; -static size_t coherent_pool_size = DEFAULT_CONSISTENT_DMA_SIZE / 8; +static struct dma_pool atomic_pool = {

• .size = SZ_256K,

+}; static int __init early_coherent_pool(char *p) {

• coherent_pool_size = memparse(p, &p);

• atomic_pool.size = memparse(p, &p); return 0;

} early_param("coherent_pool", early_coherent_pool); @@ -333,32 +289,45 @@ early_param("coherent_pool", early_coherent_pool); /*

• Initialise the coherent pool for atomic allocations.

*/ -static int __init coherent_init(void) +static int __init atomic_pool_init(void) {

• struct dma_pool *pool = &atomic_pool; pgprot_t prot = pgprot_dmacoherent(pgprot_kernel);

• size_t size = coherent_pool_size;

• unsigned long nr_pages = pool->size >> PAGE_SHIFT;
• unsigned long *bitmap; struct page *page; void *ptr;
• int bitmap_size = BITS_TO_LONGS(nr_pages) * sizeof(long);

• if (!IS_ENABLED(CONFIG_CMA))

• return 0;
  

• bitmap = kzalloc(bitmap_size, GFP_KERNEL);
• if (!bitmap)

• goto no_bitmap;
  

• ptr = __alloc_from_contiguous(NULL, size, prot, &page);

• if (IS_ENABLED(CONFIG_CMA))

• ptr = __alloc_from_contiguous(NULL, pool->size, prot, &page);
  

• else

• ptr = __alloc_remap_buffer(NULL, pool->size, GFP_KERNEL, prot,
  

• 			   &page, NULL);
  

  if (ptr) {

• coherent_head.vm_start = (unsigned long) ptr;
  

• coherent_head.vm_end = (unsigned long) ptr + size;
  

• printk(KERN_INFO "DMA: preallocated %u KiB pool for atomic coherent allocations\n",
  

•        (unsigned)size / 1024);
  

• spin_lock_init(&pool->lock);
  

• pool->vaddr = ptr;
  

• pool->page = page;
  

• pool->bitmap = bitmap;
  

• pool->nr_pages = nr_pages;
  

• pr_info("DMA: preallocated %u KiB pool for atomic coherent allocations\n",
  

•        (unsigned)pool->size / 1024);
  

  return 0; }

• printk(KERN_ERR "DMA: failed to allocate %u KiB pool for atomic coherent allocation\n",

•       (unsigned)size / 1024);
  

• kfree(bitmap);

+no_bitmap:

• pr_err("DMA: failed to allocate %u KiB pool for atomic coherent allocation\n",

•       (unsigned)pool->size / 1024);
  

  return -ENOMEM;

} /*

• CMA is activated by core_initcall, so we must be called after it.

*/ -postcore_initcall(coherent_init); +postcore_initcall(atomic_pool_init); struct dma_contig_early_reserve { phys_addr_t base; @@ -406,112 +375,6 @@ void __init dma_contiguous_remap(void) } } -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) {

• pr_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->priv = 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();
  

• 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) {

• pr_err("%s: trying to free invalid coherent area: %p\n",
  

•        __func__, cpu_addr);
  

• dump_stack();
  

• return;
  

• }
• if ((c->vm_end - c->vm_start) != size) {

• pr_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))
  

• 	pr_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);

-}

static int __dma_update_pte(pte_t *pte, pgtable_t token, unsigned long addr, void *data) { @@ -552,16 +415,17 @@ static void *__alloc_remap_buffer(struct device *dev, size_t size, gfp_t gfp, return ptr; } -static void *__alloc_from_pool(struct device *dev, size_t size,

• 	       struct page **ret_page, const void *caller)
  

+static void *__alloc_from_pool(size_t size, struct page **ret_page) {

• struct arm_vmregion *c;

• struct dma_pool *pool = &atomic_pool;
• unsigned int count = PAGE_ALIGN(size) >> PAGE_SHIFT;
• unsigned int pageno;
• unsigned long flags;
• void *ptr = NULL; size_t align;

• if (!coherent_head.vm_start) {

• printk(KERN_ERR "%s: coherent pool not initialised!\n",
  

•        __func__);
  

• dump_stack();
  

• if (!pool->vaddr) {

• WARN(1, "%s: coherent pool not initialised!\n", __func__);
  

Ditto.

return NULL;

} @@ -571,35 +435,41 @@ static void *__alloc_from_pool(struct device *dev, size_t size, * size. This helps reduce fragmentation of the DMA space. */ align = PAGE_SIZE << get_order(size);

• c = arm_vmregion_alloc(&coherent_head, align, size, 0, caller);
• if (c) {

• void *ptr = (void *)c->vm_start;
  

• struct page *page = virt_to_page(ptr);
  

• *ret_page = page;
  

• return ptr;
  

• spin_lock_irqsave(&pool->lock, flags);
• pageno = bitmap_find_next_zero_area(pool->bitmap, pool->nr_pages,

• 			    0, count, (1 << align) - 1);
  

• if (pageno < pool->nr_pages) {

• bitmap_set(pool->bitmap, pageno, count);
  

• ptr = pool->vaddr + PAGE_SIZE * pageno;
  

• *ret_page = pool->page + pageno;
  

  }

• return NULL;

• spin_unlock_irqrestore(&pool->lock, flags);
• return ptr;

} -static int __free_from_pool(void *cpu_addr, size_t size) +static int __free_from_pool(void *start, size_t size) {

• unsigned long start = (unsigned long)cpu_addr;
• unsigned long end = start + size;
• struct arm_vmregion *c;

• struct dma_pool *pool = &atomic_pool;
• unsigned long pageno, count;
• unsigned long flags;

• if (start < coherent_head.vm_start || end > coherent_head.vm_end)

• if (start < pool->vaddr || start > pool->vaddr + pool->size) return 0;

• c = arm_vmregion_find_remove(&coherent_head, (unsigned long)start);
• 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;
  

• if (start + size > pool->vaddr + pool->size) {

• WARN(1, "%s: freeing wrong coherent size from pool\n", __func__);
  

Ditto

• return 0;
  

  }

• arm_vmregion_free(&coherent_head, c);

• pageno = (start - pool->vaddr) >> PAGE_SHIFT;
• count = size >> PAGE_SHIFT;
• spin_lock_irqsave(&pool->lock, flags);
• bitmap_clear(pool->bitmap, pageno, count);
• spin_unlock_irqrestore(&pool->lock, flags);
• return 1;

} @@ -644,7 +514,7 @@ static inline pgprot_t __get_dma_pgprot(struct dma_attrs *attrs, pgprot_t prot) #define __get_dma_pgprot(attrs, prot) __pgprot(0) #define __alloc_remap_buffer(dev, size, gfp, prot, ret, c) NULL -#define __alloc_from_pool(dev, size, ret_page, c) NULL +#define __alloc_from_pool(size, ret_page) NULL #define __alloc_from_contiguous(dev, size, prot, ret) NULL #define __free_from_pool(cpu_addr, size) 0 #define __free_from_contiguous(dev, page, size) do { } while (0) @@ -702,10 +572,10 @@ static void *__dma_alloc(struct device *dev, size_t size, dma_addr_t *handle, if (arch_is_coherent() || nommu()) addr = __alloc_simple_buffer(dev, size, gfp, &page);

• else if (gfp & GFP_ATOMIC)

• addr = __alloc_from_pool(size, &page);
  

  else if (!IS_ENABLED(CONFIG_CMA)) addr = __alloc_remap_buffer(dev, size, gfp, prot, &page, caller);

• else if (gfp & GFP_ATOMIC)

• addr = __alloc_from_pool(dev, size, &page, caller);
  

  else addr = __alloc_from_contiguous(dev, size, prot, &page);

@@ -741,16 +611,22 @@ int arm_dma_mmap(struct device *dev, struct vm_area_struct *vma, { int ret = -ENXIO; #ifdef CONFIG_MMU

• unsigned long user_count = (vma->vm_end - vma->vm_start) >> PAGE_SHIFT;
• unsigned long count = PAGE_ALIGN(size) >> PAGE_SHIFT; unsigned long pfn = dma_to_pfn(dev, dma_addr);
• unsigned long off = vma->vm_pgoff;
• vma->vm_page_prot = __get_dma_pgprot(attrs, vma->vm_page_prot);

if (dma_mmap_from_coherent(dev, vma, cpu_addr, size, &ret)) return ret;

• ret = remap_pfn_range(vma, vma->vm_start,

• 	      pfn + vma->vm_pgoff,
  

• 	      vma->vm_end - vma->vm_start,
  

• 	      vma->vm_page_prot);
  

• if (off < count && user_count <= (count - off)) {

• ret = remap_pfn_range(vma, vma->vm_start,
  

• 		      pfn + off,
  

• 		      user_count << PAGE_SHIFT,
  

• 		      vma->vm_page_prot);
  

• }

What's that? Is this piece relate to this patch? I can't understand that and nitpick, naming is rather awkward. IMHO, nr_vma_pages, nr_pages would be better. Anyway, Is it a bug fix or clean up? I guess it should be another patch if I didn't miss something.

#endif /* CONFIG_MMU */ return ret; @@ -998,9 +874,6 @@ static int arm_dma_set_mask(struct device *dev, u64 dma_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; } @@ -1117,61 +990,32 @@ static int __iommu_free_buffer(struct device *dev, struct page **pages, size_t s

• Create a CPU mapping for a specified pages

*/ static void * -__iommu_alloc_remap(struct page **pages, size_t size, gfp_t gfp, pgprot_t prot) +__iommu_alloc_remap(struct page **pages, size_t size, gfp_t gfp, pgprot_t prot,

•     const void *caller)
  

{

• struct arm_vmregion *c;
• size_t align;
• size_t count = size >> PAGE_SHIFT;
• int bit;

• unsigned int i, nr_pages = PAGE_ALIGN(size) >> PAGE_SHIFT;
• struct vm_struct *area;
• unsigned long p;

• if (!consistent_pte[0]) {

• pr_err("%s: not initialised\n", __func__);
  

• dump_stack();
  

• area = get_vm_area_caller(size, VM_ARM_DMA_CONSISTENT | VM_USERMAP,

• 		  caller);
  

• if (!area) 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), NULL);
  

• if (c) {

• pte_t *pte;
  

• int idx = CONSISTENT_PTE_INDEX(c->vm_start);
  

• int i = 0;
  

• u32 off = CONSISTENT_OFFSET(c->vm_start) & (PTRS_PER_PTE-1);
  

• pte = consistent_pte[idx] + off;
  

• c->priv = pages;
  

• do {
  

• 	BUG_ON(!pte_none(*pte));
  

• 	set_pte_ext(pte, mk_pte(pages[i], prot), 0);
  

• 	pte++;
  

• 	off++;
  

• 	i++;
  

• 	if (off >= PTRS_PER_PTE) {
  

• 		off = 0;
  

• 		pte = consistent_pte[++idx];
  

• 	}
  

• } while (i < count);
  

• dsb();
  

• area->pages = pages;
• area->nr_pages = nr_pages;
• p = (unsigned long)area->addr;

• return (void *)c->vm_start;
  

• for (i = 0; i < nr_pages; i++) {

• phys_addr_t phys = __pfn_to_phys(page_to_pfn(pages[i]));
  

• if (ioremap_page_range(p, p + PAGE_SIZE, phys, prot))
  

• 	goto err;
  

• p += PAGE_SIZE;
  

  }
• return area->addr;

+err:

• unmap_kernel_range((unsigned long)area->addr, size);
• vunmap(area->addr); return NULL;

} @@ -1230,6 +1074,16 @@ static int __iommu_remove_mapping(struct device *dev, dma_addr_t iova, size_t si return 0; } +static struct page **__iommu_get_pages(void *cpu_addr) +{

• struct vm_struct *area;
• area = find_vm_area(cpu_addr);
• if (area && (area->flags & VM_ARM_DMA_CONSISTENT))

• return area->pages;
  

• return NULL;

+}

static void *arm_iommu_alloc_attrs(struct device *dev, size_t size, dma_addr_t *handle, gfp_t gfp, struct dma_attrs *attrs) { @@ -1248,7 +1102,8 @@ static void *arm_iommu_alloc_attrs(struct device *dev, size_t size, if (*handle == DMA_ERROR_CODE) goto err_buffer;

• addr = __iommu_alloc_remap(pages, size, gfp, prot);

• addr = __iommu_alloc_remap(pages, size, gfp, prot,

• 		   __builtin_return_address(0));
  

  if (!addr) goto err_mapping;

@@ -1265,31 +1120,25 @@ static int arm_iommu_mmap_attrs(struct device *dev, struct vm_area_struct *vma, void *cpu_addr, dma_addr_t dma_addr, size_t size, struct dma_attrs *attrs) {

• struct arm_vmregion *c;

• unsigned long uaddr = vma->vm_start;
• unsigned long usize = vma->vm_end - vma->vm_start;
• struct page **pages = __iommu_get_pages(cpu_addr);

vma->vm_page_prot = __get_dma_pgprot(attrs, vma->vm_page_prot);

• c = arm_vmregion_find(&consistent_head, (unsigned long)cpu_addr);

• if (c) {

• struct page **pages = c->priv;
  

• if (!pages)

• return -ENXIO;
  

• unsigned long uaddr = vma->vm_start;
  

• unsigned long usize = vma->vm_end - vma->vm_start;
  

• int i = 0;
  

• do {

• int ret = vm_insert_page(vma, uaddr, *pages++);
  

• if (ret) {
  

• 	pr_err("Remapping memory failed: %d\n", ret);
  

• 	return ret;
  

• }
  

• uaddr += PAGE_SIZE;
  

• usize -= PAGE_SIZE;
  

• } while (usize > 0);

• do {
  

• 	int ret;
  

• 	ret = vm_insert_page(vma, uaddr, pages[i++]);
  

• 	if (ret) {
  

• 		pr_err("Remapping memory, error: %d\n", ret);
  

• 		return ret;
  

• 	}
  

• 	uaddr += PAGE_SIZE;
  

• 	usize -= PAGE_SIZE;
  

• } while (usize > 0);
  

• } return 0;

} @@ -1300,16 +1149,20 @@ static int arm_iommu_mmap_attrs(struct device *dev, struct vm_area_struct *vma, void arm_iommu_free_attrs(struct device *dev, size_t size, void *cpu_addr, dma_addr_t handle, struct dma_attrs *attrs) {

• struct arm_vmregion *c;

• struct page **pages = __iommu_get_pages(cpu_addr); size = PAGE_ALIGN(size);

• c = arm_vmregion_find(&consistent_head, (unsigned long)cpu_addr);
• if (c) {

• struct page **pages = c->priv;
  

• __dma_free_remap(cpu_addr, size);
  

• __iommu_remove_mapping(dev, handle, size);
  

• __iommu_free_buffer(dev, pages, size);
  

• if (!pages) {

• WARN(1, "%s: trying to free invalid coherent area: %p\n",
  

•        __func__, cpu_addr);
  

Remove __func__.

• return;
  

  }
• unmap_kernel_range((unsigned long)cpu_addr, size);
• vunmap(cpu_addr);
• __iommu_remove_mapping(dev, handle, size);
• __iommu_free_buffer(dev, pages, size);

} /* diff --git a/arch/arm/mm/mm.h b/arch/arm/mm/mm.h index 2e8a1ef..6776160 100644 --- a/arch/arm/mm/mm.h +++ b/arch/arm/mm/mm.h @@ -59,6 +59,9 @@ extern void __flush_dcache_page(struct address_space *mapping, struct page *page #define VM_ARM_MTYPE(mt) ((mt) << 20) #define VM_ARM_MTYPE_MASK (0x1f << 20) +/* consistent regions used by dma_alloc_attrs() */ +#define VM_ARM_DMA_CONSISTENT 0x20000000

#endif #ifdef CONFIG_ZONE_DMA diff --git a/include/linux/vmalloc.h b/include/linux/vmalloc.h index 2e28f4d..6071e91 100644 --- a/include/linux/vmalloc.h +++ b/include/linux/vmalloc.h @@ -93,6 +93,7 @@ extern struct vm_struct *__get_vm_area_caller(unsigned long size, unsigned long start, unsigned long end, const void *caller); extern struct vm_struct *remove_vm_area(const void *addr); +extern struct vm_struct *find_vm_area(const void *addr); extern int map_vm_area(struct vm_struct *area, pgprot_t prot, struct page ***pages); diff --git a/mm/vmalloc.c b/mm/vmalloc.c index 11308f0..65fc4dc 100644 --- a/mm/vmalloc.c +++ b/mm/vmalloc.c @@ -1403,7 +1403,15 @@ struct vm_struct *get_vm_area_caller(unsigned long size, unsigned long flags, -1, GFP_KERNEL, caller); } -static struct vm_struct *find_vm_area(const void *addr) +/**

• • find_vm_area - find a continuous kernel virtual area
• • @addr: base address
• • Search for the kernel VM area starting at @addr, and return it.
• • It is up to the caller to do all required locking to keep the returned
• • pointer valid.
• */

+struct vm_struct *find_vm_area(const void *addr) { struct vmap_area *va; -- 1.7.1.569.g6f426

-- To unsubscribe, send a message with 'unsubscribe linux-mm' in the body to majordomo@kvack.org. For more info on Linux MM, see: http://www.linux-mm.org/ . Don't email: <a href=mailto:"dont@kvack.org"> email@kvack.org </a>