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authorJiri Kosina <jkosina@suse.cz>2011-04-26 10:22:15 +0200
committerJiri Kosina <jkosina@suse.cz>2011-04-26 10:22:59 +0200
commit07f9479a40cc778bc1462ada11f95b01360ae4ff (patch)
tree0676cf38df3844004bb3ebfd99dfa67a4a8998f5 /arch/powerpc/mm/dma-noncoherent.c
parent9d5e6bdb3013acfb311ab407eeca0b6a6a3dedbf (diff)
parentcd2e49e90f1cae7726c9a2c54488d881d7f1cd1c (diff)
downloadlinux-07f9479a40cc778bc1462ada11f95b01360ae4ff.tar.gz
Merge branch 'master' into for-next
Fast-forwarded to current state of Linus' tree as there are patches to be applied for files that didn't exist on the old branch.
Diffstat (limited to 'arch/powerpc/mm/dma-noncoherent.c')
-rw-r--r--arch/powerpc/mm/dma-noncoherent.c20
1 files changed, 20 insertions, 0 deletions
diff --git a/arch/powerpc/mm/dma-noncoherent.c b/arch/powerpc/mm/dma-noncoherent.c
index 757c0bed9a9..b42f76c4948 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);
+}