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 */