text: /*
   * This file is subject to the terms and conditions of the GNU General Public
   * License.  See the file "COPYING" in the main directory of this archive
   * for more details.
   *
   * Version from mach-generic modified to support PowerTV port
   * Portions Copyright (C) 2009  Cisco Systems, Inc.
   * Copyright (C) 2006  Ralf Baechle <ralf@linux-mips.org>
   *
   */
  
  #ifndef __ASM_MACH_POWERTV_DMA_COHERENCE_H
  #define __ASM_MACH_POWERTV_DMA_COHERENCE_H
  
  #include <linux/sched.h>
  #include <linux/device.h>
  #include <asm/mach-powertv/asic.h>
  
  static inline bool is_kseg2(void *addr)
  {
  	return (unsigned long)addr >= KSEG2;
  }
  
  static inline unsigned long virt_to_phys_from_pte(void *addr)
  {
  	pgd_t *pgd;
  	pud_t *pud;
  	pmd_t *pmd;
  	pte_t *ptep, pte;
  
  	unsigned long virt_addr = (unsigned long)addr;
  	unsigned long phys_addr = 0UL;
  
  	/* get the page global directory. */
  	pgd = pgd_offset_k(virt_addr);
  
  	if (!pgd_none(*pgd)) {
  		/* get the page upper directory */
  		pud = pud_offset(pgd, virt_addr);
  		if (!pud_none(*pud)) {
  			/* get the page middle directory */
  			pmd = pmd_offset(pud, virt_addr);
  			if (!pmd_none(*pmd)) {
  				/* get a pointer to the page table entry */
  				ptep = pte_offset(pmd, virt_addr);
  				pte = *ptep;
  				/* check for a valid page */
  				if (pte_present(pte)) {
  					/* get the physical address the page is
  					 * referring to */
  					phys_addr = (unsigned long)
  						page_to_phys(pte_page(pte));
  					/* add the offset within the page */
  					phys_addr |= (virt_addr & ~PAGE_MASK);
  				}
  			}
  		}
  	}
  
  	return phys_addr;
  }
  
  static inline dma_addr_t plat_map_dma_mem(struct device *dev, void *addr,
  	size_t size)
  {
  	if (is_kseg2(addr))
  		return phys_to_dma(virt_to_phys_from_pte(addr));
  	else
  		return phys_to_dma(virt_to_phys(addr));
  }
  
  static inline dma_addr_t plat_map_dma_mem_page(struct device *dev,
  	struct page *page)
  {
  	return phys_to_dma(page_to_phys(page));
  }
  
  static inline unsigned long plat_dma_addr_to_phys(struct device *dev,
  	dma_addr_t dma_addr)
  {
  	return dma_to_phys(dma_addr);
  }
  
  static inline void plat_unmap_dma_mem(struct device *dev, dma_addr_t dma_addr,
  	size_t size, enum dma_data_direction direction)
  {
  }
  
  static inline int plat_dma_supported(struct device *dev, u64 mask)
  {
  	/*
  	 * we fall back to GFP_DMA when the mask isn't all 1s,
  	 * so we can't guarantee allocations that must be
  	 * within a tighter range than GFP_DMA..
  	 */
  	if (mask < DMA_BIT_MASK(24))
  		return 0;
  
  	return 1;
  }
  
  static inline void plat_extra_sync_for_device(struct device *dev)
  {
  }
  
  static inline int plat_dma_mapping_error(struct device *dev,
  					 dma_addr_t dma_addr)
  {
  	return 0;
  }
  
  static inline int plat_device_is_coherent(struct device *dev)
  {
  	return 0;
  }
  
  #endif /* __ASM_MACH_POWERTV_DMA_COHERENCE_H */
  