arch/mips/include/asm/mach-powertv/dma-coherence.h

   1 /*
   2  * This file is subject to the terms and conditions of the GNU General Public
   3  * License.  See the file "COPYING" in the main directory of this archive
   4  * for more details.
   5  *
   6  * Version from mach-generic modified to support PowerTV port
   7  * Portions Copyright (C) 2009  Cisco Systems, Inc.
   8  * Copyright (C) 2006  Ralf Baechle <ralf@linux-mips.org>
   9  *
  10  */
  11
  12 #ifndef __ASM_MACH_POWERTV_DMA_COHERENCE_H
  13 #define __ASM_MACH_POWERTV_DMA_COHERENCE_H
  14
  15 #include <linux/sched.h>
  16 #include <linux/version.h>
  17 #include <linux/device.h>
  18 #include <asm/mach-powertv/asic.h>
  19
  20 static inline bool is_kseg2(void *addr)
  21 {
  22         return (unsigned long)addr >= KSEG2;
  23 }
  24
  25 static inline unsigned long virt_to_phys_from_pte(void *addr)
  26 {
  27         pgd_t *pgd;
  28         pud_t *pud;
  29         pmd_t *pmd;
  30         pte_t *ptep, pte;
  31
  32         unsigned long virt_addr = (unsigned long)addr;
  33         unsigned long phys_addr = 0UL;
  34
  35         /* get the page global directory. */
  36         pgd = pgd_offset_k(virt_addr);
  37
  38         if (!pgd_none(*pgd)) {
  39                 /* get the page upper directory */
  40                 pud = pud_offset(pgd, virt_addr);
  41                 if (!pud_none(*pud)) {
  42                         /* get the page middle directory */
  43                         pmd = pmd_offset(pud, virt_addr);
  44                         if (!pmd_none(*pmd)) {
  45                                 /* get a pointer to the page table entry */
  46                                 ptep = pte_offset(pmd, virt_addr);
  47                                 pte = *ptep;
  48                                 /* check for a valid page */
  49                                 if (pte_present(pte)) {
  50                                         /* get the physical address the page is
  51                                          * referring to */
  52                                         phys_addr = (unsigned long)
  53                                                 page_to_phys(pte_page(pte));
  54                                         /* add the offset within the page */
  55                                         phys_addr |= (virt_addr & ~PAGE_MASK);
  56                                 }
  57                         }
  58                 }
  59         }
  60
  61         return phys_addr;
  62 }
  63
  64 static inline dma_addr_t plat_map_dma_mem(struct device *dev, void *addr,
  65         size_t size)
  66 {
  67         if (is_kseg2(addr))
  68                 return phys_to_dma(virt_to_phys_from_pte(addr));
  69         else
  70                 return phys_to_dma(virt_to_phys(addr));
  71 }
  72
  73 static inline dma_addr_t plat_map_dma_mem_page(struct device *dev,
  74         struct page *page)
  75 {
  76         return phys_to_dma(page_to_phys(page));
  77 }
  78
  79 static inline unsigned long plat_dma_addr_to_phys(struct device *dev,
  80         dma_addr_t dma_addr)
  81 {
  82         return dma_to_phys(dma_addr);
  83 }
  84
  85 static inline void plat_unmap_dma_mem(struct device *dev, dma_addr_t dma_addr,
  86         size_t size, enum dma_data_direction direction)
  87 {
  88 }
  89
  90 static inline int plat_dma_supported(struct device *dev, u64 mask)
  91 {
  92         /*
  93          * we fall back to GFP_DMA when the mask isn't all 1s,
  94          * so we can't guarantee allocations that must be
  95          * within a tighter range than GFP_DMA..
  96          */
  97         if (mask < DMA_BIT_MASK(24))
  98                 return 0;
  99
 100         return 1;
 101 }
 102
 103 static inline void plat_extra_sync_for_device(struct device *dev)
 104 {
 105 }
 106
 107 static inline int plat_dma_mapping_error(struct device *dev,
 108                                          dma_addr_t dma_addr)
 109 {
 110         return 0;
 111 }
 112
 113 static inline int plat_device_is_coherent(struct device *dev)
 114 {
 115         return 0;
 116 }
 117
 118 #endif /* __ASM_MACH_POWERTV_DMA_COHERENCE_H */