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author | Lars-Peter Clausen <lars@metafoo.de> | 2014-12-03 16:07:28 +0100 |
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committer | Michal Simek <michal.simek@xilinx.com> | 2014-12-17 12:59:59 +0100 |
commit | 3a8e3265179b7e6394d7aab4d6df5651b49e7243 (patch) | |
tree | 82194a886cb05fe27ba3ddf0dca4ec05c3977e4a /arch/microblaze/mm/consistent.c | |
parent | b2776bf7149bddd1f4161f14f79520f17fc1d71d (diff) | |
download | blackbird-op-linux-3a8e3265179b7e6394d7aab4d6df5651b49e7243.tar.gz blackbird-op-linux-3a8e3265179b7e6394d7aab4d6df5651b49e7243.zip |
microblaze: Fix mmap for cache coherent memory
When running in non-cache coherent configuration the memory that was
allocated with dma_alloc_coherent() has a custom mapping and so there is no
1-to-1 relationship between the kernel virtual address and the PFN. This
means that virt_to_pfn() will not work correctly for those addresses and the
default mmap implementation in the form of dma_common_mmap() will map some
random, but not the requested, memory area.
Fix this by providing a custom mmap implementation that looks up the PFN
from the page table rather than using virt_to_pfn.
Signed-off-by: Lars-Peter Clausen <lars@metafoo.de>
Signed-off-by: Michal Simek <michal.simek@xilinx.com>
Diffstat (limited to 'arch/microblaze/mm/consistent.c')
-rw-r--r-- | arch/microblaze/mm/consistent.c | 25 |
1 files changed, 20 insertions, 5 deletions
diff --git a/arch/microblaze/mm/consistent.c b/arch/microblaze/mm/consistent.c index e10ad930895e..b06c3a7faf20 100644 --- a/arch/microblaze/mm/consistent.c +++ b/arch/microblaze/mm/consistent.c @@ -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. */ @@ -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); |