[PATCHv6 7/7] ARM: dma-mapping: add support for IOMMU mapper
Krishna Reddy
vdumpa at nvidia.com
Mon Feb 13 14:58:50 EST 2012
The implementation looks nice overall. Have few comments.
> +static struct page **__iommu_alloc_buffer(struct device *dev, size_t
> +size, gfp_t gfp) {
> + struct page **pages;
> + int count = size >> PAGE_SHIFT;
> + int i=0;
> +
> + pages = kzalloc(count * sizeof(struct page*), gfp);
> + if (!pages)
> + return NULL;
kzalloc can fail for any size bigger than PAGE_SIZE, if the system memory is
fully fragmented.
If there is a request for size bigger than 4MB, then the pages pointer array won't
Fit in one page and kzalloc may fail. we should use vzalloc()/vfree()
when pages pointer array size needed is bigger than PAGE_SIZE.
> +static inline dma_addr_t __alloc_iova(struct dma_iommu_mapping
> *mapping,
> + size_t size)
> +{
> + unsigned int order = get_order(size);
> + unsigned int align = 0;
> + unsigned int count, start;
> + unsigned long flags;
> +
> + count = ((PAGE_ALIGN(size) >> PAGE_SHIFT) +
> + (1 << mapping->order) - 1) >> mapping->order;
> +
> + if (order > mapping->order)
> + align = (1 << (order - mapping->order)) - 1;
> +
> + spin_lock_irqsave(&mapping->lock, flags);
> + start = bitmap_find_next_zero_area(mapping->bitmap, mapping-
> >bits, 0,
> + count, align);
Do we need "align" here? Why is it trying to align the memory request to
size of memory requested? When mapping->order is zero and if the size
requested is 4MB, order becomes 10. align is set to 1023.
bitmap_find_next_zero_area looks searching for free area from index, which
is multiple of 1024. Why we can't we say align mask as 0 and let it allocate from
next free index? Doesn't mapping->order take care of min alignment needed for dev?
> +static dma_addr_t __iommu_create_mapping(struct device *dev, struct
> +page **pages, size_t size) {
> + struct dma_iommu_mapping *mapping = dev->archdata.mapping;
> + unsigned int count = PAGE_ALIGN(size) >> PAGE_SHIFT;
> + dma_addr_t dma_addr, iova;
> + int i, ret = ~0;
> +
> + dma_addr = __alloc_iova(mapping, size);
> + if (dma_addr == ~0)
> + goto fail;
> +
> + iova = dma_addr;
> + for (i=0; i<count; ) {
> + unsigned int phys = page_to_phys(pages[i]);
> + int j = i + 1;
> +
> + while (j < count) {
> + if (page_to_phys(pages[j]) != phys + (j - i) *
> PAGE_SIZE)
> + break;
> + j++;
> + }
> +
> + ret = iommu_map(mapping->domain, iova, phys, (j - i) *
> PAGE_SIZE, 0);
> + if (ret < 0)
> + goto fail;
> + iova += (j - i) * PAGE_SIZE;
> + i = j;
> + }
> +
> + return dma_addr;
> +fail:
> + return ~0;
> +}
iommu_map failure should release the iova space allocated using __alloc_iova.
> +static dma_addr_t arm_iommu_map_page(struct device *dev, struct page
> *page,
> + unsigned long offset, size_t size, enum dma_data_direction dir,
> + struct dma_attrs *attrs)
> +{
> + struct dma_iommu_mapping *mapping = dev->archdata.mapping;
> + dma_addr_t dma_addr, iova;
> + unsigned int phys;
> + int ret, len = PAGE_ALIGN(size + offset);
> +
> + if (!arch_is_coherent())
> + __dma_page_cpu_to_dev(page, offset, size, dir);
> +
> + dma_addr = iova = __alloc_iova(mapping, len);
> + if (iova == ~0)
> + goto fail;
> +
> + dma_addr += offset;
> + phys = page_to_phys(page);
> + ret = iommu_map(mapping->domain, iova, phys, size, 0);
> + if (ret < 0)
> + goto fail;
> +
> + return dma_addr;
> +fail:
> + return ~0;
> +}
iommu_map failure should release the iova space allocated using __alloc_iova.
>+ printk(KERN_INFO "Attached IOMMU controller to %s device.\n", dev_name(dev));
Just nit-picking. Should use pr_info().
--nvpublic
-KR
> -----Original Message-----
> From: Marek Szyprowski [mailto:m.szyprowski at samsung.com]
> Sent: Friday, February 10, 2012 10:59 AM
> To: linux-arm-kernel at lists.infradead.org; linaro-mm-sig at lists.linaro.org;
> linux-mm at kvack.org; linux-arch at vger.kernel.org; linux-samsung-
> soc at vger.kernel.org; iommu at lists.linux-foundation.org
> Cc: Marek Szyprowski; Kyungmin Park; Arnd Bergmann; Joerg Roedel; Russell
> King - ARM Linux; Shariq Hasnain; Chunsang Jeong; Krishna Reddy; KyongHo
> Cho; Andrzej Pietrasiewicz; Benjamin Herrenschmidt
> Subject: [PATCHv6 7/7] ARM: dma-mapping: add support for IOMMU
> mapper
>
> This patch add a complete implementation of DMA-mapping API for devices
> that have IOMMU support. All DMA-mapping calls are supported.
>
> This patch contains some of the code kindly provided by Krishna Reddy
> <vdumpa at nvidia.com> and Andrzej Pietrasiewicz
> <andrzej.p at samsung.com>
>
> Signed-off-by: Marek Szyprowski <m.szyprowski at samsung.com>
> Signed-off-by: Kyungmin Park <kyungmin.park at samsung.com>
> ---
> arch/arm/Kconfig | 8 +
> arch/arm/include/asm/device.h | 3 +
> arch/arm/include/asm/dma-iommu.h | 34 ++
> arch/arm/mm/dma-mapping.c | 635
> +++++++++++++++++++++++++++++++++++++-
> arch/arm/mm/vmregion.h | 2 +-
> 5 files changed, 667 insertions(+), 15 deletions(-) create mode 100644
> arch/arm/include/asm/dma-iommu.h
>
> diff --git a/arch/arm/Kconfig b/arch/arm/Kconfig index 59102fb..5d9a0b6
> 100644
> --- a/arch/arm/Kconfig
> +++ b/arch/arm/Kconfig
> @@ -44,6 +44,14 @@ config ARM
> config ARM_HAS_SG_CHAIN
> bool
>
> +config NEED_SG_DMA_LENGTH
> + bool
> +
> +config ARM_DMA_USE_IOMMU
> + select NEED_SG_DMA_LENGTH
> + select ARM_HAS_SG_CHAIN
> + bool
> +
> config HAVE_PWM
> bool
>
> diff --git a/arch/arm/include/asm/device.h
> b/arch/arm/include/asm/device.h index 6e2cb0e..b69c0d3 100644
> --- a/arch/arm/include/asm/device.h
> +++ b/arch/arm/include/asm/device.h
> @@ -14,6 +14,9 @@ struct dev_archdata {
> #ifdef CONFIG_IOMMU_API
> void *iommu; /* private IOMMU data */
> #endif
> +#ifdef CONFIG_ARM_DMA_USE_IOMMU
> + struct dma_iommu_mapping *mapping;
> +#endif
> };
>
> struct omap_device;
> diff --git a/arch/arm/include/asm/dma-iommu.h
> b/arch/arm/include/asm/dma-iommu.h
> new file mode 100644
> index 0000000..799b094
> --- /dev/null
> +++ b/arch/arm/include/asm/dma-iommu.h
> @@ -0,0 +1,34 @@
> +#ifndef ASMARM_DMA_IOMMU_H
> +#define ASMARM_DMA_IOMMU_H
> +
> +#ifdef __KERNEL__
> +
> +#include <linux/mm_types.h>
> +#include <linux/scatterlist.h>
> +#include <linux/dma-debug.h>
> +#include <linux/kmemcheck.h>
> +
> +struct dma_iommu_mapping {
> + /* iommu specific data */
> + struct iommu_domain *domain;
> +
> + void *bitmap;
> + size_t bits;
> + unsigned int order;
> + dma_addr_t base;
> +
> + spinlock_t lock;
> + struct kref kref;
> +};
> +
> +struct dma_iommu_mapping *
> +arm_iommu_create_mapping(struct bus_type *bus, dma_addr_t base,
> size_t size,
> + int order);
> +
> +void arm_iommu_release_mapping(struct dma_iommu_mapping
> *mapping);
> +
> +int arm_iommu_attach_device(struct device *dev,
> + struct dma_iommu_mapping
> *mapping);
> +
> +#endif /* __KERNEL__ */
> +#endif
> diff --git a/arch/arm/mm/dma-mapping.c b/arch/arm/mm/dma-mapping.c
> index 4845c09..4163691 100644
> --- a/arch/arm/mm/dma-mapping.c
> +++ b/arch/arm/mm/dma-mapping.c
> @@ -19,6 +19,7 @@
> #include <linux/dma-mapping.h>
> #include <linux/highmem.h>
> #include <linux/slab.h>
> +#include <linux/iommu.h>
>
> #include <asm/memory.h>
> #include <asm/highmem.h>
> @@ -26,6 +27,7 @@
> #include <asm/tlbflush.h>
> #include <asm/sizes.h>
> #include <asm/mach/arch.h>
> +#include <asm/dma-iommu.h>
>
> #include "mm.h"
>
> @@ -156,6 +158,19 @@ static u64 get_coherent_dma_mask(struct device
> *dev)
> return mask;
> }
>
> +static void __dma_clear_buffer(struct page *page, size_t size) {
> + void *ptr;
> + /*
> + * 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); }
> +
> /*
> * Allocate a DMA buffer for 'dev' of size 'size' using the
> * specified gfp mask. Note that 'size' must be page aligned.
> @@ -164,7 +179,6 @@ static struct page *__dma_alloc_buffer(struct device
> *dev, size_t size, gfp_t gf {
> unsigned long order = get_order(size);
> struct page *page, *p, *e;
> - void *ptr;
> u64 mask = get_coherent_dma_mask(dev);
>
> #ifdef CONFIG_DMA_API_DEBUG
> @@ -193,14 +207,7 @@ static struct page *__dma_alloc_buffer(struct device
> *dev, size_t size, gfp_t gf
> 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);
> + __dma_clear_buffer(page, size);
>
> return page;
> }
> @@ -348,7 +355,7 @@ __dma_alloc_remap(struct page *page, size_t size,
> gfp_t gfp, pgprot_t prot)
> u32 off = CONSISTENT_OFFSET(c->vm_start) &
> (PTRS_PER_PTE-1);
>
> pte = consistent_pte[idx] + off;
> - c->vm_pages = page;
> + c->priv = page;
>
> do {
> BUG_ON(!pte_none(*pte));
> @@ -461,6 +468,14 @@ __dma_alloc(struct device *dev, size_t size,
> dma_addr_t *handle, gfp_t gfp,
> return addr;
> }
>
> +static inline pgprot_t __get_dma_pgprot(struct dma_attrs *attrs,
> +pgprot_t prot) {
> + prot = dma_get_attr(DMA_ATTR_WRITE_COMBINE, attrs) ?
> + pgprot_writecombine(prot) :
> + pgprot_dmacoherent(prot);
> + return prot;
> +}
> +
> /*
> * Allocate DMA-coherent memory space and return both the kernel
> remapped
> * virtual and bus address for that space.
> @@ -468,9 +483,7 @@ __dma_alloc(struct device *dev, size_t size,
> dma_addr_t *handle, gfp_t gfp, void *arm_dma_alloc(struct device *dev,
> size_t size, dma_addr_t *handle,
> gfp_t gfp, struct dma_attrs *attrs) {
> - pgprot_t prot = dma_get_attr(DMA_ATTR_WRITE_COMBINE, attrs) ?
> - pgprot_writecombine(pgprot_kernel) :
> - pgprot_dmacoherent(pgprot_kernel);
> + pgprot_t prot = __get_dma_pgprot(attrs, pgprot_kernel);
> void *memory;
>
> if (dma_alloc_from_coherent(dev, size, handle, &memory)) @@ -
> 499,13 +512,14 @@ int arm_dma_mmap(struct device *dev, struct
> vm_area_struct *vma,
> c = arm_vmregion_find(&consistent_head, (unsigned
> long)cpu_addr);
> if (c) {
> unsigned long off = vma->vm_pgoff;
> + struct page *pages = c->priv;
>
> 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,
> + page_to_pfn(pages) + off,
> user_size << PAGE_SHIFT,
> vma->vm_page_prot);
> }
> @@ -644,6 +658,9 @@ int arm_dma_map_sg(struct device *dev, struct
> scatterlist *sg, int nents,
> int i, j;
>
> for_each_sg(sg, s, nents, i) {
> +#ifdef CONFIG_NEED_SG_DMA_LENGTH
> + s->dma_length = s->length;
> +#endif
> s->dma_address = ops->map_page(dev, sg_page(s), s-
> >offset,
> s->length, dir, attrs);
> if (dma_mapping_error(dev, s->dma_address)) @@ -749,3
> +766,593 @@ static int __init dma_debug_do_init(void)
> return 0;
> }
> fs_initcall(dma_debug_do_init);
> +
> +#ifdef CONFIG_ARM_DMA_USE_IOMMU
> +
> +/* IOMMU */
> +
> +static inline dma_addr_t __alloc_iova(struct dma_iommu_mapping
> *mapping,
> + size_t size)
> +{
> + unsigned int order = get_order(size);
> + unsigned int align = 0;
> + unsigned int count, start;
> + unsigned long flags;
> +
> + count = ((PAGE_ALIGN(size) >> PAGE_SHIFT) +
> + (1 << mapping->order) - 1) >> mapping->order;
> +
> + if (order > mapping->order)
> + align = (1 << (order - mapping->order)) - 1;
> +
> + spin_lock_irqsave(&mapping->lock, flags);
> + start = bitmap_find_next_zero_area(mapping->bitmap, mapping-
> >bits, 0,
> + count, align);
> + if (start > mapping->bits) {
> + spin_unlock_irqrestore(&mapping->lock, flags);
> + return ~0;
> + }
> +
> + bitmap_set(mapping->bitmap, start, count);
> + spin_unlock_irqrestore(&mapping->lock, flags);
> +
> + return mapping->base + (start << (mapping->order + PAGE_SHIFT));
> }
> +
> +static inline void __free_iova(struct dma_iommu_mapping *mapping,
> + dma_addr_t addr, size_t size) {
> + unsigned int start = (addr - mapping->base) >>
> + (mapping->order + PAGE_SHIFT);
> + unsigned int count = ((size >> PAGE_SHIFT) +
> + (1 << mapping->order) - 1) >> mapping->order;
> + unsigned long flags;
> +
> + spin_lock_irqsave(&mapping->lock, flags);
> + bitmap_clear(mapping->bitmap, start, count);
> + spin_unlock_irqrestore(&mapping->lock, flags); }
> +
> +static struct page **__iommu_alloc_buffer(struct device *dev, size_t
> +size, gfp_t gfp) {
> + struct page **pages;
> + int count = size >> PAGE_SHIFT;
> + int i=0;
> +
> + pages = kzalloc(count * sizeof(struct page*), gfp);
> + if (!pages)
> + return NULL;
> +
> + while (count) {
> + int j, order = __ffs(count);
> +
> + pages[i] = alloc_pages(gfp | __GFP_NOWARN, order);
> + while (!pages[i] && order)
> + pages[i] = alloc_pages(gfp | __GFP_NOWARN, --
> order);
> + if (!pages[i])
> + goto error;
> +
> + if (order)
> + split_page(pages[i], order);
> + j = 1 << order;
> + while (--j)
> + pages[i + j] = pages[i] + j;
> +
> + __dma_clear_buffer(pages[i], PAGE_SIZE << order);
> + i += 1 << order;
> + count -= 1 << order;
> + }
> +
> + return pages;
> +error:
> + while (--i)
> + if (pages[i])
> + __free_pages(pages[i], 0);
> + kfree(pages);
> + return NULL;
> +}
> +
> +static int __iommu_free_buffer(struct device *dev, struct page **pages,
> +size_t size) {
> + int count = size >> PAGE_SHIFT;
> + int i;
> + for (i=0; i< count; i++)
> + if (pages[i])
> + __free_pages(pages[i], 0);
> + kfree(pages);
> + return 0;
> +}
> +
> +static void *
> +__iommu_alloc_remap(struct page **pages, size_t size, gfp_t gfp,
> +pgprot_t prot) {
> + struct arm_vmregion *c;
> + size_t align;
> + size_t count = size >> PAGE_SHIFT;
> + int bit;
> +
> + if (!consistent_pte[0]) {
> + 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));
> + 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();
> +
> + return (void *)c->vm_start;
> + }
> + return NULL;
> +}
> +
> +static dma_addr_t __iommu_create_mapping(struct device *dev, struct
> +page **pages, size_t size) {
> + struct dma_iommu_mapping *mapping = dev->archdata.mapping;
> + unsigned int count = PAGE_ALIGN(size) >> PAGE_SHIFT;
> + dma_addr_t dma_addr, iova;
> + int i, ret = ~0;
> +
> + dma_addr = __alloc_iova(mapping, size);
> + if (dma_addr == ~0)
> + goto fail;
> +
> + iova = dma_addr;
> + for (i=0; i<count; ) {
> + unsigned int phys = page_to_phys(pages[i]);
> + int j = i + 1;
> +
> + while (j < count) {
> + if (page_to_phys(pages[j]) != phys + (j - i) *
> PAGE_SIZE)
> + break;
> + j++;
> + }
> +
> + ret = iommu_map(mapping->domain, iova, phys, (j - i) *
> PAGE_SIZE, 0);
> + if (ret < 0)
> + goto fail;
> + iova += (j - i) * PAGE_SIZE;
> + i = j;
> + }
> +
> + return dma_addr;
> +fail:
> + return ~0;
> +}
> +
> +static int __iommu_remove_mapping(struct device *dev, dma_addr_t iova,
> +size_t size) {
> + struct dma_iommu_mapping *mapping = dev->archdata.mapping;
> + unsigned int count = PAGE_ALIGN(size) >> PAGE_SHIFT;
> +
> + iova &= PAGE_MASK;
> +
> + iommu_unmap(mapping->domain, iova, count * PAGE_SIZE);
> +
> + __free_iova(mapping, iova, size);
> + return 0;
> +}
> +
> +static void *arm_iommu_alloc_attrs(struct device *dev, size_t size,
> + dma_addr_t *handle, gfp_t gfp, struct dma_attrs *attrs) {
> + pgprot_t prot = __get_dma_pgprot(attrs, pgprot_kernel);
> + struct page **pages;
> + void *addr = NULL;
> +
> + *handle = ~0;
> + size = PAGE_ALIGN(size);
> +
> + pages = __iommu_alloc_buffer(dev, size, gfp);
> + if (!pages)
> + return NULL;
> +
> + *handle = __iommu_create_mapping(dev, pages, size);
> + if (*handle == ~0)
> + goto err_buffer;
> +
> + addr = __iommu_alloc_remap(pages, size, gfp, prot);
> + if (!addr)
> + goto err_mapping;
> +
> + return addr;
> +
> +err_mapping:
> + __iommu_remove_mapping(dev, *handle, size);
> +err_buffer:
> + __iommu_free_buffer(dev, pages, size);
> + return NULL;
> +}
> +
> +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;
> +
> + 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;
> +
> + unsigned long uaddr = vma->vm_start;
> + unsigned long usize = vma->vm_end - vma->vm_start;
> + int i = 0;
> +
> + do {
> + int ret;
> +
> + ret = vm_insert_page(vma, uaddr, pages[i++]);
> + if (ret) {
> + printk(KERN_ERR "Remapping memory,
> error: %d\n", ret);
> + return ret;
> + }
> +
> + uaddr += PAGE_SIZE;
> + usize -= PAGE_SIZE;
> + } while (usize > 0);
> + }
> + return 0;
> +}
> +
> +/*
> + * free a page as defined by the above mapping.
> + * Must not be called with IRQs disabled.
> + */
> +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;
> + 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);
> + }
> +}
> +
> +static int __map_sg_chunk(struct device *dev, struct scatterlist *sg,
> + size_t size, dma_addr_t *handle,
> + enum dma_data_direction dir)
> +{
> + struct dma_iommu_mapping *mapping = dev->archdata.mapping;
> + dma_addr_t iova, iova_base;
> + int ret = 0;
> + unsigned int count;
> + struct scatterlist *s;
> +
> + size = PAGE_ALIGN(size);
> + *handle = ~0;
> +
> + iova_base = iova = __alloc_iova(mapping, size);
> + if (iova == ~0)
> + return -ENOMEM;
> +
> + for (count = 0, s = sg; count < (size >> PAGE_SHIFT); s = sg_next(s))
> + {
> + phys_addr_t phys = page_to_phys(sg_page(s));
> + unsigned int len = PAGE_ALIGN(s->offset + s->length);
> +
> + if (!arch_is_coherent())
> + __dma_page_cpu_to_dev(sg_page(s), s->offset, s-
> >length, dir);
> +
> + ret = iommu_map(mapping->domain, iova, phys, len, 0);
> + if (ret < 0)
> + goto fail;
> + count += len >> PAGE_SHIFT;
> + iova += len;
> + }
> + *handle = iova_base;
> +
> + return 0;
> +fail:
> + iommu_unmap(mapping->domain, iova_base, count * PAGE_SIZE);
> + __free_iova(mapping, iova_base, size);
> + return ret;
> +}
> +
> +int arm_iommu_map_sg(struct device *dev, struct scatterlist *sg, int nents,
> + enum dma_data_direction dir, struct dma_attrs *attrs) {
> + struct scatterlist *s = sg, *dma = sg, *start = sg;
> + int i, count = 0;
> + unsigned int offset = s->offset;
> + unsigned int size = s->offset + s->length;
> + unsigned int max = dma_get_max_seg_size(dev);
> +
> + s->dma_address = ~0;
> + s->dma_length = 0;
> +
> + for (i = 1; i < nents; i++) {
> + s->dma_address = ~0;
> + s->dma_length = 0;
> +
> + s = sg_next(s);
> +
> + if (s->offset || (size & ~PAGE_MASK) || size + s->length >
> max) {
> + if (__map_sg_chunk(dev, start, size, &dma-
> >dma_address,
> + dir) < 0)
> + goto bad_mapping;
> +
> + dma->dma_address += offset;
> + dma->dma_length = size - offset;
> +
> + size = offset = s->offset;
> + start = s;
> + dma = sg_next(dma);
> + count += 1;
> + }
> + size += s->length;
> + }
> + if (__map_sg_chunk(dev, start, size, &dma->dma_address, dir) < 0)
> + goto bad_mapping;
> +
> + dma->dma_address += offset;
> + dma->dma_length = size - offset;
> +
> + return count+1;
> +
> +bad_mapping:
> + for_each_sg(sg, s, count, i)
> + __iommu_remove_mapping(dev, sg_dma_address(s),
> sg_dma_len(s));
> + return 0;
> +}
> +
> +void arm_iommu_unmap_sg(struct device *dev, struct scatterlist *sg, int
> nents,
> + enum dma_data_direction dir, struct dma_attrs
> *attrs) {
> + struct scatterlist *s;
> + int i;
> +
> + for_each_sg(sg, s, nents, i) {
> + if (sg_dma_len(s))
> + __iommu_remove_mapping(dev,
> sg_dma_address(s),
> + sg_dma_len(s));
> + if (!arch_is_coherent())
> + __dma_page_dev_to_cpu(sg_page(s), s->offset,
> + s->length, dir);
> + }
> +}
> +
> +
> +/**
> + * dma_sync_sg_for_cpu
> + * @dev: valid struct device pointer, or NULL for ISA and EISA-like
> +devices
> + * @sg: list of buffers
> + * @nents: number of buffers to map (returned from dma_map_sg)
> + * @dir: DMA transfer direction (same as was passed to dma_map_sg) */
> +void arm_iommu_sync_sg_for_cpu(struct device *dev, struct scatterlist
> *sg,
> + int nents, enum dma_data_direction dir) {
> + struct scatterlist *s;
> + int i;
> +
> + for_each_sg(sg, s, nents, i)
> + if (!arch_is_coherent())
> + __dma_page_dev_to_cpu(sg_page(s), s->offset, s-
> >length, dir);
> +
> +}
> +
> +/**
> + * dma_sync_sg_for_device
> + * @dev: valid struct device pointer, or NULL for ISA and EISA-like
> +devices
> + * @sg: list of buffers
> + * @nents: number of buffers to map (returned from dma_map_sg)
> + * @dir: DMA transfer direction (same as was passed to dma_map_sg) */
> +void arm_iommu_sync_sg_for_device(struct device *dev, struct scatterlist
> *sg,
> + int nents, enum dma_data_direction dir) {
> + struct scatterlist *s;
> + int i;
> +
> + for_each_sg(sg, s, nents, i)
> + if (!arch_is_coherent())
> + __dma_page_cpu_to_dev(sg_page(s), s->offset, s-
> >length, dir); }
> +
> +static dma_addr_t arm_iommu_map_page(struct device *dev, struct page
> *page,
> + unsigned long offset, size_t size, enum dma_data_direction dir,
> + struct dma_attrs *attrs)
> +{
> + struct dma_iommu_mapping *mapping = dev->archdata.mapping;
> + dma_addr_t dma_addr, iova;
> + unsigned int phys;
> + int ret, len = PAGE_ALIGN(size + offset);
> +
> + if (!arch_is_coherent())
> + __dma_page_cpu_to_dev(page, offset, size, dir);
> +
> + dma_addr = iova = __alloc_iova(mapping, len);
> + if (iova == ~0)
> + goto fail;
> +
> + dma_addr += offset;
> + phys = page_to_phys(page);
> + ret = iommu_map(mapping->domain, iova, phys, size, 0);
> + if (ret < 0)
> + goto fail;
> +
> + return dma_addr;
> +fail:
> + return ~0;
> +}
> +
> +static void arm_iommu_unmap_page(struct device *dev, dma_addr_t
> handle,
> + size_t size, enum dma_data_direction dir,
> + struct dma_attrs *attrs)
> +{
> + struct dma_iommu_mapping *mapping = dev->archdata.mapping;
> + dma_addr_t iova = handle & PAGE_MASK;
> + struct page *page = phys_to_page(iommu_iova_to_phys(mapping-
> >domain, iova));
> + int offset = handle & ~PAGE_MASK;
> +
> + if (!iova)
> + return;
> +
> + if (!arch_is_coherent())
> + __dma_page_dev_to_cpu(page, offset, size, dir);
> +
> + iommu_unmap(mapping->domain, iova, size);
> + __free_iova(mapping, iova, size);
> +}
> +
> +static void arm_iommu_sync_single_for_cpu(struct device *dev,
> + dma_addr_t handle, size_t size, enum dma_data_direction
> dir) {
> + struct dma_iommu_mapping *mapping = dev->archdata.mapping;
> + dma_addr_t iova = handle & PAGE_MASK;
> + struct page *page = phys_to_page(iommu_iova_to_phys(mapping-
> >domain, iova));
> + unsigned int offset = handle & ~PAGE_MASK;
> +
> + if (!iova)
> + return;
> +
> + if (!arch_is_coherent())
> + __dma_page_dev_to_cpu(page, offset, size, dir); }
> +
> +static void arm_iommu_sync_single_for_device(struct device *dev,
> + dma_addr_t handle, size_t size, enum dma_data_direction
> dir) {
> + struct dma_iommu_mapping *mapping = dev->archdata.mapping;
> + dma_addr_t iova = handle & PAGE_MASK;
> + struct page *page = phys_to_page(iommu_iova_to_phys(mapping-
> >domain, iova));
> + unsigned int offset = handle & ~PAGE_MASK;
> +
> + if (!iova)
> + return;
> +
> + __dma_page_cpu_to_dev(page, offset, size, dir); }
> +
> +struct dma_map_ops iommu_ops = {
> + .alloc = arm_iommu_alloc_attrs,
> + .free = arm_iommu_free_attrs,
> + .mmap = arm_iommu_mmap_attrs,
> +
> + .map_page = arm_iommu_map_page,
> + .unmap_page = arm_iommu_unmap_page,
> + .sync_single_for_cpu = arm_iommu_sync_single_for_cpu,
> + .sync_single_for_device =
> arm_iommu_sync_single_for_device,
> +
> + .map_sg = arm_iommu_map_sg,
> + .unmap_sg = arm_iommu_unmap_sg,
> + .sync_sg_for_cpu = arm_iommu_sync_sg_for_cpu,
> + .sync_sg_for_device = arm_iommu_sync_sg_for_device,
> +};
> +
> +struct dma_iommu_mapping *
> +arm_iommu_create_mapping(struct bus_type *bus, dma_addr_t base,
> size_t size,
> + int order)
> +{
> + unsigned int count = (size >> PAGE_SHIFT) - order;
> + unsigned int bitmap_size = BITS_TO_LONGS(count) * sizeof(long);
> + struct dma_iommu_mapping *mapping;
> + int err = -ENOMEM;
> +
> + mapping = kzalloc(sizeof(struct dma_iommu_mapping),
> GFP_KERNEL);
> + if (!mapping)
> + goto err;
> +
> + mapping->bitmap = kzalloc(bitmap_size, GFP_KERNEL);
> + if (!mapping->bitmap)
> + goto err2;
> +
> + mapping->base = base;
> + mapping->bits = bitmap_size;
> + mapping->order = order;
> + spin_lock_init(&mapping->lock);
> +
> + mapping->domain = iommu_domain_alloc(bus);
> + if (!mapping->domain)
> + goto err3;
> +
> + kref_init(&mapping->kref);
> + return mapping;
> +err3:
> + kfree(mapping->bitmap);
> +err2:
> + kfree(mapping);
> +err:
> + return ERR_PTR(err);
> +}
> +EXPORT_SYMBOL(arm_iommu_create_mapping);
> +
> +static void release_iommu_mapping(struct kref *kref) {
> + struct dma_iommu_mapping *mapping =
> + container_of(kref, struct dma_iommu_mapping, kref);
> +
> + iommu_domain_free(mapping->domain);
> + kfree(mapping->bitmap);
> + kfree(mapping);
> +}
> +
> +void arm_iommu_release_mapping(struct dma_iommu_mapping
> *mapping) {
> + if (mapping)
> + kref_put(&mapping->kref, release_iommu_mapping); }
> +EXPORT_SYMBOL(arm_iommu_release_mapping);
> +
> +int arm_iommu_attach_device(struct device *dev,
> + struct dma_iommu_mapping *mapping) {
> + int err;
> +
> + err = iommu_attach_device(mapping->domain, dev);
> + if (err)
> + return err;
> +
> + kref_get(&mapping->kref);
> + dev->archdata.mapping = mapping;
> + set_dma_ops(dev, &iommu_ops);
> +
> + printk(KERN_INFO "Attached IOMMU controller to %s device.\n",
> dev_name(dev));
> + return 0;
> +}
> +EXPORT_SYMBOL(arm_iommu_attach_device);
> +
> +#endif
> diff --git a/arch/arm/mm/vmregion.h b/arch/arm/mm/vmregion.h index
> 15e9f04..6bbc402 100644
> --- a/arch/arm/mm/vmregion.h
> +++ b/arch/arm/mm/vmregion.h
> @@ -17,7 +17,7 @@ struct arm_vmregion {
> struct list_head vm_list;
> unsigned long vm_start;
> unsigned long vm_end;
> - struct page *vm_pages;
> + void *priv;
> int vm_active;
> };
>
> --
> 1.7.1.569.g6f426
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