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/device.h>
  17 #include <asm/mach-powertv/asic.h>
  18
  19 static inline bool is_kseg2(void *addr)
  20 {
  21         return (unsigned long)addr >= KSEG2;
  22 }
  23
  24 static inline unsigned long virt_to_phys_from_pte(void *addr)
  25 {
  26         pgd_t *pgd;
  27         pud_t *pud;
  28         pmd_t *pmd;
  29         pte_t *ptep, pte;
  30
  31         unsigned long virt_addr = (unsigned long)addr;
  32         unsigned long phys_addr = 0UL;
  33
  34         /* get the page global directory. */
  35         pgd = pgd_offset_k(virt_addr);
  36
  37         if (!pgd_none(*pgd)) {
  38                 /* get the page upper directory */
  39                 pud = pud_offset(pgd, virt_addr);
  40                 if (!pud_none(*pud)) {
  41                         /* get the page middle directory */
  42                         pmd = pmd_offset(pud, virt_addr);
  43                         if (!pmd_none(*pmd)) {
  44                                 /* get a pointer to the page table entry */
  45                                 ptep = pte_offset(pmd, virt_addr);
  46                                 pte = *ptep;
  47                                 /* check for a valid page */
  48                                 if (pte_present(pte)) {
  49                                         /* get the physical address the page is
  50                                          * referring to */
  51                                         phys_addr = (unsigned long)
  52                                                 page_to_phys(pte_page(pte));
  53                                         /* add the offset within the page */
  54                                         phys_addr |= (virt_addr & ~PAGE_MASK);
  55                                 }
  56                         }
  57                 }
  58         }
  59
  60         return phys_addr;
  61 }
  62
  63 static inline dma_addr_t plat_map_dma_mem(struct device *dev, void *addr,
  64         size_t size)
  65 {
  66         if (is_kseg2(addr))
  67                 return phys_to_dma(virt_to_phys_from_pte(addr));
  68         else
  69                 return phys_to_dma(virt_to_phys(addr));
  70 }
  71
  72 static inline dma_addr_t plat_map_dma_mem_page(struct device *dev,
  73         struct page *page)
  74 {
  75         return phys_to_dma(page_to_phys(page));
  76 }
  77
  78 static inline unsigned long plat_dma_addr_to_phys(struct device *dev,
  79         dma_addr_t dma_addr)
  80 {
  81         return dma_to_phys(dma_addr);
  82 }
  83
  84 static inline void plat_unmap_dma_mem(struct device *dev, dma_addr_t dma_addr,
  85         size_t size, enum dma_data_direction direction)
  86 {
  87 }
  88
  89 static inline int plat_dma_supported(struct device *dev, u64 mask)
  90 {
  91         /*
  92          * we fall back to GFP_DMA when the mask isn't all 1s,
  93          * so we can't guarantee allocations that must be
  94          * within a tighter range than GFP_DMA..
  95          */
  96         if (mask < DMA_BIT_MASK(24))
  97                 return 0;
  98
  99         return 1;
 100 }
 101
 102 static inline void plat_extra_sync_for_device(struct device *dev)
 103 {
 104 }
 105
 106 static inline int plat_dma_mapping_error(struct device *dev,
 107                                          dma_addr_t dma_addr)
 108 {
 109         return 0;
 110 }
 111
 112 static inline int plat_device_is_coherent(struct device *dev)
 113 {
 114         return 0;
 115 }
 116
 117 #endif /* __ASM_MACH_POWERTV_DMA_COHERENCE_H */