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authorLars-Peter Clausen <lars@metafoo.de>2014-12-03 16:07:28 +0100
committerMichal Simek <michal.simek@xilinx.com>2014-12-17 12:59:59 +0100
commit3a8e3265179b7e6394d7aab4d6df5651b49e7243 (patch)
tree82194a886cb05fe27ba3ddf0dca4ec05c3977e4a /arch/microblaze/mm/consistent.c
parentb2776bf7149bddd1f4161f14f79520f17fc1d71d (diff)
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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.c25
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);
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