LXR linux/arch/arm/include/asm/xen/page-coherent.h

   1#ifndef _ASM_ARM_XEN_PAGE_COHERENT_H
   2#define _ASM_ARM_XEN_PAGE_COHERENT_H
   3
   4#include <asm/page.h>
   5#include <linux/dma-mapping.h>
   6
   7void __xen_dma_map_page(struct device *hwdev, struct page *page,
   8             dma_addr_t dev_addr, unsigned long offset, size_t size,
   9             enum dma_data_direction dir, unsigned long attrs);
  10void __xen_dma_unmap_page(struct device *hwdev, dma_addr_t handle,
  11                size_t size, enum dma_data_direction dir,
  12                unsigned long attrs);
  13void __xen_dma_sync_single_for_cpu(struct device *hwdev,
  14                dma_addr_t handle, size_t size, enum dma_data_direction dir);
  15
  16void __xen_dma_sync_single_for_device(struct device *hwdev,
  17                dma_addr_t handle, size_t size, enum dma_data_direction dir);
  18
  19static inline void *xen_alloc_coherent_pages(struct device *hwdev, size_t size,
  20                dma_addr_t *dma_handle, gfp_t flags, unsigned long attrs)
  21{
  22        return __generic_dma_ops(hwdev)->alloc(hwdev, size, dma_handle, flags, attrs);
  23}
  24
  25static inline void xen_free_coherent_pages(struct device *hwdev, size_t size,
  26                void *cpu_addr, dma_addr_t dma_handle, unsigned long attrs)
  27{
  28        __generic_dma_ops(hwdev)->free(hwdev, size, cpu_addr, dma_handle, attrs);
  29}
  30
  31static inline void xen_dma_map_page(struct device *hwdev, struct page *page,
  32             dma_addr_t dev_addr, unsigned long offset, size_t size,
  33             enum dma_data_direction dir, unsigned long attrs)
  34{
  35        unsigned long page_pfn = page_to_xen_pfn(page);
  36        unsigned long dev_pfn = XEN_PFN_DOWN(dev_addr);
  37        unsigned long compound_pages =
  38                (1<<compound_order(page)) * XEN_PFN_PER_PAGE;
  39        bool local = (page_pfn <= dev_pfn) &&
  40                (dev_pfn - page_pfn < compound_pages);
  41
  42        /*
  43         * Dom0 is mapped 1:1, while the Linux page can span across
  44         * multiple Xen pages, it's not possible for it to contain a
  45         * mix of local and foreign Xen pages. So if the first xen_pfn
  46         * == mfn the page is local otherwise it's a foreign page
  47         * grant-mapped in dom0. If the page is local we can safely
  48         * call the native dma_ops function, otherwise we call the xen
  49         * specific function.
  50         */
  51        if (local)
  52                __generic_dma_ops(hwdev)->map_page(hwdev, page, offset, size, dir, attrs);
  53        else
  54                __xen_dma_map_page(hwdev, page, dev_addr, offset, size, dir, attrs);
  55}
  56
  57static inline void xen_dma_unmap_page(struct device *hwdev, dma_addr_t handle,
  58                size_t size, enum dma_data_direction dir, unsigned long attrs)
  59{
  60        unsigned long pfn = PFN_DOWN(handle);
  61        /*
  62         * Dom0 is mapped 1:1, while the Linux page can be spanned accross
  63         * multiple Xen page, it's not possible to have a mix of local and
  64         * foreign Xen page. Dom0 is mapped 1:1, so calling pfn_valid on a
  65         * foreign mfn will always return false. If the page is local we can
  66         * safely call the native dma_ops function, otherwise we call the xen
  67         * specific function.
  68         */
  69        if (pfn_valid(pfn)) {
  70                if (__generic_dma_ops(hwdev)->unmap_page)
  71                        __generic_dma_ops(hwdev)->unmap_page(hwdev, handle, size, dir, attrs);
  72        } else
  73                __xen_dma_unmap_page(hwdev, handle, size, dir, attrs);
  74}
  75
  76static inline void xen_dma_sync_single_for_cpu(struct device *hwdev,
  77                dma_addr_t handle, size_t size, enum dma_data_direction dir)
  78{
  79        unsigned long pfn = PFN_DOWN(handle);
  80        if (pfn_valid(pfn)) {
  81                if (__generic_dma_ops(hwdev)->sync_single_for_cpu)
  82                        __generic_dma_ops(hwdev)->sync_single_for_cpu(hwdev, handle, size, dir);
  83        } else
  84                __xen_dma_sync_single_for_cpu(hwdev, handle, size, dir);
  85}
  86
  87static inline void xen_dma_sync_single_for_device(struct device *hwdev,
  88                dma_addr_t handle, size_t size, enum dma_data_direction dir)
  89{
  90        unsigned long pfn = PFN_DOWN(handle);
  91        if (pfn_valid(pfn)) {
  92                if (__generic_dma_ops(hwdev)->sync_single_for_device)
  93                        __generic_dma_ops(hwdev)->sync_single_for_device(hwdev, handle, size, dir);
  94        } else
  95                __xen_dma_sync_single_for_device(hwdev, handle, size, dir);
  96}
  97
  98#endif /* _ASM_ARM_XEN_PAGE_COHERENT_H */
  99