[PATCH] MIPS: Flush huge TLB

[Hillf Danton <dhillf@gmail.com>]

When flushing TLB, if @vma is backed by huge page, we could flush huge TLB,
due to that huge page is defined to be far from normal page.

Signed-off-by: Hillf Danton <dhillf@gmail.com>
---

--- a/arch/mips/mm/tlb-r4k.c    Mon May 30 21:17:04 2011
+++ b/arch/mips/mm/tlb-r4k.c    Fri Nov 18 21:13:13 2011
@@ -120,22 +120,30 @@ void local_flush_tlb_range(struct vm_are

        if (cpu_context(cpu, mm) != 0) {
                unsigned long size, flags;
+               int huge = is_vm_hugetlb_page(vma);

                ENTER_CRITICAL(flags);
-               size = (end - start + (PAGE_SIZE - 1)) >> PAGE_SHIFT;
-               size = (size + 1) >> 1;
+               if (huge) {
+                       start = round_down(start, HPAGE_SIZE);
+                       end = round_up(end, HPAGE_SIZE);
+                       size = (end - start) >> HPAGE_SHIFT;
+               } else {
+                       start = round_down(start, PAGE_SIZE << 1);
+                       end = round_up(end, PAGE_SIZE << 1);
+                       size = (end - start) >> (PAGE_SHIFT + 1);
+               }
                if (size <= current_cpu_data.tlbsize/2) {
                        int oldpid = read_c0_entryhi();
                        int newpid = cpu_asid(cpu, mm);

-                       start &= (PAGE_MASK << 1);
-                       end += ((PAGE_SIZE << 1) - 1);
-                       end &= (PAGE_MASK << 1);
                        while (start < end) {
                                int idx;

                                write_c0_entryhi(start | newpid);
-                               start += (PAGE_SIZE << 1);
+                               if (huge)
+                                       start += HPAGE_SIZE;
+                               else
+                                       start += (PAGE_SIZE << 1);
                                mtc0_tlbw_hazard();
                                tlb_probe();
                                tlb_probe_hazard();