From 3a8e3265179b7e6394d7aab4d6df5651b49e7243 Mon Sep 17 00:00:00 2001 From: Lars-Peter Clausen Date: Wed, 3 Dec 2014 16:07:28 +0100 Subject: 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 Signed-off-by: Michal Simek --- arch/microblaze/mm/consistent.c | 25 ++++++++++++++++++++----- 1 file changed, 20 insertions(+), 5 deletions(-) (limited to 'arch/microblaze/mm') 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); -- cgit v1.2.3