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Merge tag 'microblaze-3.19-rc1' of git://git.monstr.eu/linux-2.6-micr…
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…oblaze

Pull Microblaze fix from Michal Simek:
 "Fix mmap for cache coherent memory"

* tag 'microblaze-3.19-rc1' of git://git.monstr.eu/linux-2.6-microblaze:
  microblaze: Fix mmap for cache coherent memory
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Linus Torvalds committed Dec 17, 2014
2 parents 5f5425e + 3a8e326 commit 0ea90b9
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Showing 3 changed files with 48 additions and 5 deletions.
1 change: 1 addition & 0 deletions arch/microblaze/include/asm/pgtable.h
Original file line number Diff line number Diff line change
Expand Up @@ -565,6 +565,7 @@ void consistent_free(size_t size, void *vaddr);
void consistent_sync(void *vaddr, size_t size, int direction);
void consistent_sync_page(struct page *page, unsigned long offset,
size_t size, int direction);
unsigned long consistent_virt_to_pfn(void *vaddr);

void setup_memory(void);
#endif /* __ASSEMBLY__ */
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27 changes: 27 additions & 0 deletions arch/microblaze/kernel/dma.c
Original file line number Diff line number Diff line change
Expand Up @@ -154,9 +154,36 @@ dma_direct_sync_sg_for_device(struct device *dev,
__dma_sync(sg->dma_address, sg->length, direction);
}

int dma_direct_mmap_coherent(struct device *dev, struct vm_area_struct *vma,
void *cpu_addr, dma_addr_t handle, size_t size,
struct dma_attrs *attrs)
{
#ifdef CONFIG_MMU
unsigned long user_count = (vma->vm_end - vma->vm_start) >> PAGE_SHIFT;
unsigned long count = PAGE_ALIGN(size) >> PAGE_SHIFT;
unsigned long off = vma->vm_pgoff;
unsigned long pfn;

if (off >= count || user_count > (count - off))
return -ENXIO;

#ifdef NOT_COHERENT_CACHE
vma->vm_page_prot = pgprot_noncached(vma->vm_page_prot);
pfn = consistent_virt_to_pfn(cpu_addr);
#else
pfn = virt_to_pfn(cpu_addr);
#endif
return remap_pfn_range(vma, vma->vm_start, pfn + off,
vma->vm_end - vma->vm_start, vma->vm_page_prot);
#else
return -ENXIO;
#endif
}

struct dma_map_ops dma_direct_ops = {
.alloc = dma_direct_alloc_coherent,
.free = dma_direct_free_coherent,
.mmap = dma_direct_mmap_coherent,
.map_sg = dma_direct_map_sg,
.dma_supported = dma_direct_dma_supported,
.map_page = dma_direct_map_page,
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25 changes: 20 additions & 5 deletions arch/microblaze/mm/consistent.c
Original file line number Diff line number Diff line change
Expand Up @@ -156,6 +156,25 @@ void *consistent_alloc(gfp_t gfp, size_t size, dma_addr_t *dma_handle)
}
EXPORT_SYMBOL(consistent_alloc);

#ifdef CONFIG_MMU
static pte_t *consistent_virt_to_pte(void *vaddr)
{
unsigned long addr = (unsigned long)vaddr;

return pte_offset_kernel(pmd_offset(pgd_offset_k(addr), addr), addr);
}

unsigned long consistent_virt_to_pfn(void *vaddr)
{
pte_t *ptep = consistent_virt_to_pte(vaddr);

if (pte_none(*ptep) || !pte_present(*ptep))
return 0;

return pte_pfn(*ptep);
}
#endif

/*
* free page(s) as defined by the above mapping.
*/
Expand All @@ -181,13 +200,9 @@ void consistent_free(size_t size, void *vaddr)
} while (size -= PAGE_SIZE);
#else
do {
pte_t *ptep;
pte_t *ptep = consistent_virt_to_pte(vaddr);
unsigned long pfn;

ptep = pte_offset_kernel(pmd_offset(pgd_offset_k(
(unsigned int)vaddr),
(unsigned int)vaddr),
(unsigned int)vaddr);
if (!pte_none(*ptep) && pte_present(*ptep)) {
pfn = pte_pfn(*ptep);
pte_clear(&init_mm, (unsigned int)vaddr, ptep);
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