include/xen/arm/page-coherent.h

   1 /* SPDX-License-Identifier: GPL-2.0 */
   2 #ifndef _ASM_ARM_XEN_PAGE_COHERENT_H
   3 #define _ASM_ARM_XEN_PAGE_COHERENT_H
   4
   5 #include <asm/page.h>
   6 #include <asm/dma-mapping.h>
   7 #include <linux/dma-mapping.h>
   8
   9 static inline const struct dma_map_ops *xen_get_dma_ops(struct device *dev)
  10 {
  11         if (dev && dev->archdata.dev_dma_ops)
  12                 return dev->archdata.dev_dma_ops;
  13         return get_arch_dma_ops(NULL);
  14 }
  15
  16 void __xen_dma_map_page(struct device *hwdev, struct page *page,
  17              dma_addr_t dev_addr, unsigned long offset, size_t size,
  18              enum dma_data_direction dir, unsigned long attrs);
  19 void __xen_dma_unmap_page(struct device *hwdev, dma_addr_t handle,
  20                 size_t size, enum dma_data_direction dir,
  21                 unsigned long attrs);
  22 void __xen_dma_sync_single_for_cpu(struct device *hwdev,
  23                 dma_addr_t handle, size_t size, enum dma_data_direction dir);
  24
  25 void __xen_dma_sync_single_for_device(struct device *hwdev,
  26                 dma_addr_t handle, size_t size, enum dma_data_direction dir);
  27
  28 static inline void *xen_alloc_coherent_pages(struct device *hwdev, size_t size,
  29                 dma_addr_t *dma_handle, gfp_t flags, unsigned long attrs)
  30 {
  31         return xen_get_dma_ops(hwdev)->alloc(hwdev, size, dma_handle, flags, attrs);
  32 }
  33
  34 static inline void xen_free_coherent_pages(struct device *hwdev, size_t size,
  35                 void *cpu_addr, dma_addr_t dma_handle, unsigned long attrs)
  36 {
  37         xen_get_dma_ops(hwdev)->free(hwdev, size, cpu_addr, dma_handle, attrs);
  38 }
  39
  40 static inline void xen_dma_map_page(struct device *hwdev, struct page *page,
  41              dma_addr_t dev_addr, unsigned long offset, size_t size,
  42              enum dma_data_direction dir, unsigned long attrs)
  43 {
  44         unsigned long page_pfn = page_to_xen_pfn(page);
  45         unsigned long dev_pfn = XEN_PFN_DOWN(dev_addr);
  46         unsigned long compound_pages =
  47                 (1<<compound_order(page)) * XEN_PFN_PER_PAGE;
  48         bool local = (page_pfn <= dev_pfn) &&
  49                 (dev_pfn - page_pfn < compound_pages);
  50
  51         /*
  52          * Dom0 is mapped 1:1, while the Linux page can span across
  53          * multiple Xen pages, it's not possible for it to contain a
  54          * mix of local and foreign Xen pages. So if the first xen_pfn
  55          * == mfn the page is local otherwise it's a foreign page
  56          * grant-mapped in dom0. If the page is local we can safely
  57          * call the native dma_ops function, otherwise we call the xen
  58          * specific function.
  59          */
  60         if (local)
  61                 xen_get_dma_ops(hwdev)->map_page(hwdev, page, offset, size, dir, attrs);
  62         else
  63                 __xen_dma_map_page(hwdev, page, dev_addr, offset, size, dir, attrs);
  64 }
  65
  66 static inline void xen_dma_unmap_page(struct device *hwdev, dma_addr_t handle,
  67                 size_t size, enum dma_data_direction dir, unsigned long attrs)
  68 {
  69         unsigned long pfn = PFN_DOWN(handle);
  70         /*
  71          * Dom0 is mapped 1:1, while the Linux page can be spanned accross
  72          * multiple Xen page, it's not possible to have a mix of local and
  73          * foreign Xen page. Dom0 is mapped 1:1, so calling pfn_valid on a
  74          * foreign mfn will always return false. If the page is local we can
  75          * safely call the native dma_ops function, otherwise we call the xen
  76          * specific function.
  77          */
  78         if (pfn_valid(pfn)) {
  79                 if (xen_get_dma_ops(hwdev)->unmap_page)
  80                         xen_get_dma_ops(hwdev)->unmap_page(hwdev, handle, size, dir, attrs);
  81         } else
  82                 __xen_dma_unmap_page(hwdev, handle, size, dir, attrs);
  83 }
  84
  85 static inline void xen_dma_sync_single_for_cpu(struct device *hwdev,
  86                 dma_addr_t handle, size_t size, enum dma_data_direction dir)
  87 {
  88         unsigned long pfn = PFN_DOWN(handle);
  89         if (pfn_valid(pfn)) {
  90                 if (xen_get_dma_ops(hwdev)->sync_single_for_cpu)
  91                         xen_get_dma_ops(hwdev)->sync_single_for_cpu(hwdev, handle, size, dir);
  92         } else
  93                 __xen_dma_sync_single_for_cpu(hwdev, handle, size, dir);
  94 }
  95
  96 static inline void xen_dma_sync_single_for_device(struct device *hwdev,
  97                 dma_addr_t handle, size_t size, enum dma_data_direction dir)
  98 {
  99         unsigned long pfn = PFN_DOWN(handle);
 100         if (pfn_valid(pfn)) {
 101                 if (xen_get_dma_ops(hwdev)->sync_single_for_device)
 102                         xen_get_dma_ops(hwdev)->sync_single_for_device(hwdev, handle, size, dir);
 103         } else
 104                 __xen_dma_sync_single_for_device(hwdev, handle, size, dir);
 105 }
 106
 107 #endif /* _ASM_ARM_XEN_PAGE_COHERENT_H */