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