1 files changed, 32 insertions, 10 deletions

diff --git a/arch/avr32/kernel/entry-avr32b.S b/arch/avr32/kernel/entry-avr32b.S
index 3cdd7071f35e..2b398cae110c 100644
--- a/arch/avr32/kernel/entry-avr32b.S
+++ b/arch/avr32/kernel/entry-avr32b.S
@@ -98,10 +98,6 @@ tlb_miss_common:
         mfsr    r0, SYSREG_TLBEAR
         mfsr    r1, SYSREG_PTBR
 
-        /* Is it the vmalloc space? */
-        bld     r0, 31
-        brcs    handle_vmalloc_miss
-
         /*
          * First level lookup: The PGD contains virtual pointers to
          * the second-level page tables, but they may be NULL if not
@@ -143,15 +139,13 @@ pgtbl_lookup:
         tlbmiss_restore
         rete
 
-handle_vmalloc_miss:
-        /* Simply do the lookup in init's page table */
-        mov     r1, lo(swapper_pg_dir)
-        orh     r1, hi(swapper_pg_dir)
-        rjmp    pgtbl_lookup
-
         /* The slow path of the TLB miss handler */
         .align  2
 page_table_not_present:
+        /* Do we need to synchronize with swapper_pg_dir? */
+        bld     r0, 31
+        brcs    sync_with_swapper_pg_dir
+
 page_not_present:
         tlbmiss_restore
         sub     sp, 4
@@ -162,6 +156,34 @@ page_not_present:
         rcall   do_page_fault
         rjmp    ret_from_exception
 
+        .align  2
+sync_with_swapper_pg_dir:
+        /*
+         * If swapper_pg_dir contains a non-NULL second-level page
+         * table pointer, copy it into the current PGD. If not, we
+         * must handle it as a full-blown page fault.
+         *
+         * Jumping back to pgtbl_lookup causes an unnecessary lookup,
+         * but it is guaranteed to be a cache hit, it won't happen
+         * very often, and we absolutely do not want to sacrifice any
+         * performance in the fast path in order to improve this.
+         */
+        mov     r1, lo(swapper_pg_dir)
+        orh     r1, hi(swapper_pg_dir)
+        ld.w    r3, r1[r2 << 2]
+        cp.w    r3, 0
+        breq    page_not_present
+        mfsr    r1, SYSREG_PTBR
+        st.w    r1[r2 << 2], r3
+        rjmp    pgtbl_lookup
+
+        /*
+         * We currently have two bytes left at this point until we
+         * crash into the system call handler...
+         *
+         * Don't worry, the assembler will let us know.
+         */
+
 
         /* ---                    System Call                    --- */