[SPARC64]: Fix D-cache corruption in mremap

If we move a mapping from one virtual address to another,
and this changes the virtual color of the mapping to those
pages, we can see corrupt data due to D-cache aliasing.

Check for and deal with this by overriding the move_pte()
macro.  Set things up so that other platforms can cleanly
override the move_pte() macro too.

Signed-off-by: David S. Miller <davem@davemloft.net>

1 files changed, 17 insertions, 0 deletions

diff --git a/include/asm-sparc64/pgtable.h b/include/asm-sparc64/pgtable.h
index c44e7466534e..cd464f469a2c 100644
--- a/include/asm-sparc64/pgtable.h
+++ b/include/asm-sparc64/pgtable.h
@@ -689,6 +689,23 @@ static inline void set_pte_at(struct mm_struct *mm, unsigned long addr, pte_t *p
 #define pte_clear(mm,addr,ptep)         \
         set_pte_at((mm), (addr), (ptep), __pte(0UL))
 
+#ifdef DCACHE_ALIASING_POSSIBLE
+#define __HAVE_ARCH_MOVE_PTE
+#define move_pte(pte, prot, old_addr, new_addr)                         \
+({                                                                      \
+        pte_t newpte = (pte);                                           \
+        if (tlb_type != hypervisor && pte_present(pte)) {               \
+                unsigned long this_pfn = pte_pfn(pte);                  \
+                                                                        \
+                if (pfn_valid(this_pfn) &&                              \
+                    (((old_addr) ^ (new_addr)) & (1 << 13)))            \
+                        flush_dcache_page_all(current->mm,              \
+                                              pfn_to_page(this_pfn));   \
+        }                                                               \
+        newpte;                                                         \
+})
+#endif
+
 extern pgd_t swapper_pg_dir[2048];
 extern pmd_t swapper_low_pmd_dir[2048];