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| author | Mark Brown <broonie@opensource.wolfsonmicro.com> | 2011-04-18 18:12:14 +0200 |
|---|---|---|
| committer | Mark Brown <broonie@opensource.wolfsonmicro.com> | 2011-04-18 18:12:14 +0200 |
| commit | fac56c2df51bc29b07b3c2dcfabf32a015a0522c (patch) | |
| tree | 1ff5d84ecf4ea0bcbd42e2ef9624b5ade3810890 /arch/powerpc/mm/dma-noncoherent.c | |
| parent | ARM: s3c2440: gta02; Register dfbmcs320 device for BT audio interface (diff) | |
| parent | Linux 2.6.39-rc3 (diff) | |
| download | linux-fac56c2df51bc29b07b3c2dcfabf32a015a0522c.tar.xz linux-fac56c2df51bc29b07b3c2dcfabf32a015a0522c.zip | |
Merge commit 'v2.6.39-rc3' into for-2.6.39
Diffstat (limited to 'arch/powerpc/mm/dma-noncoherent.c')
| -rw-r--r-- | arch/powerpc/mm/dma-noncoherent.c | 20 |
1 files changed, 20 insertions, 0 deletions
diff --git a/arch/powerpc/mm/dma-noncoherent.c b/arch/powerpc/mm/dma-noncoherent.c index 757c0bed9a91..b42f76c4948d 100644 --- a/arch/powerpc/mm/dma-noncoherent.c +++ b/arch/powerpc/mm/dma-noncoherent.c @@ -399,3 +399,23 @@ void __dma_sync_page(struct page *page, unsigned long offset, #endif } EXPORT_SYMBOL(__dma_sync_page); + +/* + * Return the PFN for a given cpu virtual address returned by + * __dma_alloc_coherent. This is used by dma_mmap_coherent() + */ +unsigned long __dma_get_coherent_pfn(unsigned long cpu_addr) +{ + /* This should always be populated, so we don't test every + * level. If that fails, we'll have a nice crash which + * will be as good as a BUG_ON() + */ + pgd_t *pgd = pgd_offset_k(cpu_addr); + pud_t *pud = pud_offset(pgd, cpu_addr); + pmd_t *pmd = pmd_offset(pud, cpu_addr); + pte_t *ptep = pte_offset_kernel(pmd, cpu_addr); + + if (pte_none(*ptep) || !pte_present(*ptep)) + return 0; + return pte_pfn(*ptep); +} |