lkml.org 
[lkml]   [2019]   [Mar]   [27]   [last100]   RSS Feed
Views: [wrap][no wrap]   [headers]  [forward] 
 
Messages in this thread
    Patch in this message
    /
    From
    Subject[PATCH 11/21] dma-iommu: refactor page array remap helpers
    Date
    Move the call to dma_common_pages_remap / dma_common_free_remap  into
    __iommu_dma_alloc / __iommu_dma_free and rename those functions to
    better describe what they do. This keeps the functionality that
    allocates and remaps a non-contigous array of pages nicely abstracted
    out from the calling code.

    Signed-off-by: Christoph Hellwig <hch@lst.de>
    ---
    drivers/iommu/dma-iommu.c | 75 +++++++++++++++++++--------------------
    1 file changed, 36 insertions(+), 39 deletions(-)

    diff --git a/drivers/iommu/dma-iommu.c b/drivers/iommu/dma-iommu.c
    index 4d46beeea5b7..2013c650718a 100644
    --- a/drivers/iommu/dma-iommu.c
    +++ b/drivers/iommu/dma-iommu.c
    @@ -524,51 +524,57 @@ static struct page **__iommu_dma_alloc_pages(struct device *dev,
    }

    /**
    - * iommu_dma_free - Free a buffer allocated by __iommu_dma_alloc()
    + * iommu_dma_free_remap - Free a buffer allocated by iommu_dma_alloc_remap
    * @dev: Device which owns this buffer
    - * @pages: Array of buffer pages as returned by __iommu_dma_alloc()
    * @size: Size of buffer in bytes
    + * @cpu_address: Virtual address of the buffer
    * @handle: DMA address of buffer
    *
    * Frees both the pages associated with the buffer, and the array
    * describing them
    */
    -static void __iommu_dma_free(struct device *dev, struct page **pages,
    - size_t size, dma_addr_t *handle)
    +static void iommu_dma_free_remap(struct device *dev, size_t size,
    + void *cpu_addr, dma_addr_t dma_handle)
    {
    - __iommu_dma_unmap(iommu_get_dma_domain(dev), *handle, size);
    - __iommu_dma_free_pages(pages, PAGE_ALIGN(size) >> PAGE_SHIFT);
    - *handle = DMA_MAPPING_ERROR;
    + struct vm_struct *area = find_vm_area(cpu_addr);
    +
    + if (WARN_ON(!area || !area->pages))
    + return;
    + __iommu_dma_unmap(iommu_get_dma_domain(dev), dma_handle, size);
    + __iommu_dma_free_pages(area->pages, PAGE_ALIGN(size) >> PAGE_SHIFT);
    + dma_common_free_remap(cpu_addr, PAGE_ALIGN(size), VM_USERMAP);
    }

    /**
    - * __iommu_dma_alloc - Allocate and map a buffer contiguous in IOVA space
    + * iommu_dma_alloc_remap - Allocate and map a buffer contiguous in IOVA space
    * @dev: Device to allocate memory for. Must be a real device
    * attached to an iommu_dma_domain
    * @size: Size of buffer in bytes
    + * @dma_handle: Out argument for allocated DMA handle
    * @gfp: Allocation flags
    * @attrs: DMA attributes for this allocation
    - * @prot: IOMMU mapping flags
    - * @handle: Out argument for allocated DMA handle
    *
    * If @size is less than PAGE_SIZE, then a full CPU page will be allocated,
    * but an IOMMU which supports smaller pages might not map the whole thing.
    *
    - * Return: Array of struct page pointers describing the buffer,
    - * or NULL on failure.
    + * Return: Mapped virtual address, or NULL on failure.
    */
    -static struct page **__iommu_dma_alloc(struct device *dev, size_t size,
    - gfp_t gfp, unsigned long attrs, int prot, dma_addr_t *handle)
    +static void *iommu_dma_alloc_remap(struct device *dev, size_t size,
    + dma_addr_t *dma_handle, gfp_t gfp, unsigned long attrs)
    {
    struct iommu_domain *domain = iommu_get_dma_domain(dev);
    struct iommu_dma_cookie *cookie = domain->iova_cookie;
    struct iova_domain *iovad = &cookie->iovad;
    + bool coherent = dev_is_dma_coherent(dev);
    + int ioprot = dma_info_to_prot(DMA_BIDIRECTIONAL, coherent, attrs);
    + pgprot_t prot = arch_dma_mmap_pgprot(dev, PAGE_KERNEL, attrs);
    + unsigned int count, min_size, alloc_sizes = domain->pgsize_bitmap;
    struct page **pages;
    struct sg_table sgt;
    dma_addr_t iova;
    - unsigned int count, min_size, alloc_sizes = domain->pgsize_bitmap;
    + void *vaddr;

    - *handle = DMA_MAPPING_ERROR;
    + *dma_handle = DMA_MAPPING_ERROR;

    min_size = alloc_sizes & -alloc_sizes;
    if (min_size < PAGE_SIZE) {
    @@ -594,7 +600,7 @@ static struct page **__iommu_dma_alloc(struct device *dev, size_t size,
    if (sg_alloc_table_from_pages(&sgt, pages, count, 0, size, GFP_KERNEL))
    goto out_free_iova;

    - if (!(prot & IOMMU_CACHE)) {
    + if (!(ioprot & IOMMU_CACHE)) {
    struct scatterlist *sg;
    int i;

    @@ -602,14 +608,21 @@ static struct page **__iommu_dma_alloc(struct device *dev, size_t size,
    arch_dma_prep_coherent(sg_page(sg), sg->length);
    }

    - if (iommu_map_sg(domain, iova, sgt.sgl, sgt.orig_nents, prot)
    + if (iommu_map_sg(domain, iova, sgt.sgl, sgt.orig_nents, ioprot)
    < size)
    goto out_free_sg;

    - *handle = iova;
    + vaddr = dma_common_pages_remap(pages, size, VM_USERMAP, prot,
    + __builtin_return_address(0));
    + if (!vaddr)
    + goto out_unmap;
    +
    + *dma_handle = iova;
    sg_free_table(&sgt);
    - return pages;
    + return vaddr;

    +out_unmap:
    + __iommu_dma_unmap(domain, iova, size);
    out_free_sg:
    sg_free_table(&sgt);
    out_free_iova:
    @@ -1013,18 +1026,7 @@ static void *iommu_dma_alloc(struct device *dev, size_t size,
    size >> PAGE_SHIFT);
    }
    } else {
    - pgprot_t prot = arch_dma_mmap_pgprot(dev, PAGE_KERNEL, attrs);
    - struct page **pages;
    -
    - pages = __iommu_dma_alloc(dev, iosize, gfp, attrs, ioprot,
    - handle);
    - if (!pages)
    - return NULL;
    -
    - addr = dma_common_pages_remap(pages, size, VM_USERMAP, prot,
    - __builtin_return_address(0));
    - if (!addr)
    - __iommu_dma_free(dev, pages, iosize, handle);
    + addr = iommu_dma_alloc_remap(dev, iosize, handle, gfp, attrs);
    }
    return addr;
    }
    @@ -1038,7 +1040,7 @@ static void iommu_dma_free(struct device *dev, size_t size, void *cpu_addr,
    /*
    * @cpu_addr will be one of 4 things depending on how it was allocated:
    * - A remapped array of pages for contiguous allocations.
    - * - A remapped array of pages from __iommu_dma_alloc(), for all
    + * - A remapped array of pages from iommu_dma_alloc_remap(), for all
    * non-atomic allocations.
    * - A non-cacheable alias from the atomic pool, for atomic
    * allocations by non-coherent devices.
    @@ -1056,12 +1058,7 @@ static void iommu_dma_free(struct device *dev, size_t size, void *cpu_addr,
    dma_release_from_contiguous(dev, page, size >> PAGE_SHIFT);
    dma_common_free_remap(cpu_addr, size, VM_USERMAP);
    } else if (is_vmalloc_addr(cpu_addr)){
    - struct vm_struct *area = find_vm_area(cpu_addr);
    -
    - if (WARN_ON(!area || !area->pages))
    - return;
    - __iommu_dma_free(dev, area->pages, iosize, &handle);
    - dma_common_free_remap(cpu_addr, size, VM_USERMAP);
    + iommu_dma_free_remap(dev, iosize, cpu_addr, handle);
    } else {
    __iommu_dma_unmap_page(dev, handle, iosize, 0, 0);
    __free_pages(virt_to_page(cpu_addr), get_order(size));
    --
    2.20.1
    \
     
     \ /
      Last update: 2019-03-27 09:06    [W:4.142 / U:0.256 seconds]
    ©2003-2020 Jasper Spaans|hosted at Digital Ocean and TransIP|Read the blog|Advertise on this site