LXR linux/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
  19static inline bool is_kseg2(void *addr)
  20{
  21        return (unsigned long)addr >= KSEG2;
  22}
  23
  24static 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
  63static 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
  72static 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
  78static 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
  84static 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
  89static 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
 102static inline void plat_extra_sync_for_device(struct device *dev)
 103{
 104}
 105
 106static inline int plat_dma_mapping_error(struct device *dev,
 107                                         dma_addr_t dma_addr)
 108{
 109        return 0;
 110}
 111
 112static inline int plat_device_is_coherent(struct device *dev)
 113{
 114        return 0;
 115}
 116
 117#endif /* __ASM_MACH_POWERTV_DMA_COHERENCE_H */
 118