1 files changed, 22 insertions, 7 deletions

diff --git a/arch/arc/mm/tlb.c b/arch/arc/mm/tlb.c
index 003d69ac6ffa..066145b5f348 100644
--- a/arch/arc/mm/tlb.c
+++ b/arch/arc/mm/tlb.c
@@ -421,25 +421,40 @@ void create_tlb(struct vm_area_struct *vma, unsigned long address, pte_t *ptep)
 /*
  * Called at the end of pagefault, for a userspace mapped page
  *  -pre-install the corresponding TLB entry into MMU
- *  -Finalize the delayed D-cache flush (wback+inv kernel mapping)
+ *  -Finalize the delayed D-cache flush of kernel mapping of page due to
+ *      flush_dcache_page(), copy_user_page()
+ *
+ * Note that flush (when done) involves both WBACK - so physical page is
+ * in sync as well as INV - so any non-congruent aliases don't remain
  */
 void update_mmu_cache(struct vm_area_struct *vma, unsigned long vaddr_unaligned,
                       pte_t *ptep)
 {
         unsigned long vaddr = vaddr_unaligned & PAGE_MASK;
+        unsigned long paddr = pte_val(*ptep) & PAGE_MASK;
 
         create_tlb(vma, vaddr, ptep);
 
-        /* icache doesn't snoop dcache, thus needs to be made coherent here */
-        if (vma->vm_flags & VM_EXEC) {
+        /*
+         * Exec page : Independent of aliasing/page-color considerations,
+         *             since icache doesn't snoop dcache on ARC, any dirty
+         *             K-mapping of a code page needs to be wback+inv so that
+         *             icache fetch by userspace sees code correctly.
+         * !EXEC page: If K-mapping is NOT congruent to U-mapping, flush it
+         *             so userspace sees the right data.
+         *  (Avoids the flush for Non-exec + congruent mapping case)
+         */
+        if (vma->vm_flags & VM_EXEC || addr_not_cache_congruent(paddr, vaddr)) {
                 struct page *page = pfn_to_page(pte_pfn(*ptep));
 
-                /* if page was dcache dirty, flush now */
                 int dirty = test_and_clear_bit(PG_arch_1, &page->flags);
                 if (dirty) {
-                        unsigned long paddr =  pte_val(*ptep) & PAGE_MASK;
-                        __flush_dcache_page(paddr);
-                        __inv_icache_page(paddr, vaddr);
+                        /* wback + inv dcache lines */
+                        __flush_dcache_page(paddr, paddr);
+
+                        /* invalidate any existing icache lines */
+                        if (vma->vm_flags & VM_EXEC)
+                                __inv_icache_page(paddr, vaddr);
                 }
         }
 }