1 files changed, 53 insertions, 35 deletions

diff --git a/arch/avr32/kernel/entry-avr32b.S b/arch/avr32/kernel/entry-avr32b.S
index 5f31702d6b1c..2b398cae110c 100644
--- a/arch/avr32/kernel/entry-avr32b.S
+++ b/arch/avr32/kernel/entry-avr32b.S
@@ -74,50 +74,41 @@ exception_vectors:
         .align  2
         bral    do_dtlb_modified
 
-        /*
-         * r0 : PGD/PT/PTE
-         * r1 : Offending address
-         * r2 : Scratch register
-         * r3 : Cause (5, 12 or 13)
-         */
 #define tlbmiss_save    pushm   r0-r3
 #define tlbmiss_restore popm    r0-r3
 
-        .section .tlbx.ex.text,"ax",@progbits
+        .org    0x50
         .global itlb_miss
 itlb_miss:
         tlbmiss_save
         rjmp    tlb_miss_common
 
-        .section .tlbr.ex.text,"ax",@progbits
+        .org    0x60
 dtlb_miss_read:
         tlbmiss_save
         rjmp    tlb_miss_common
 
-        .section .tlbw.ex.text,"ax",@progbits
+        .org    0x70
 dtlb_miss_write:
         tlbmiss_save
 
         .global tlb_miss_common
+        .align  2
 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 */
+        /*
+         * First level lookup: The PGD contains virtual pointers to
+         * the second-level page tables, but they may be NULL if not
+         * present.
+         */
 pgtbl_lookup:
         lsr     r2, r0, PGDIR_SHIFT
         ld.w    r3, r1[r2 << 2]
         bfextu  r1, r0, PAGE_SHIFT, PGDIR_SHIFT - PAGE_SHIFT
-        bld     r3, _PAGE_BIT_PRESENT
-        brcc    page_table_not_present
-
-        /* Translate to virtual address in P1. */
-        andl    r3, 0xf000
-        sbr     r3, 31
+        cp.w    r3, 0
+        breq    page_table_not_present
 
         /* Second level lookup */
         ld.w    r2, r3[r1 << 2]
@@ -148,16 +139,55 @@ pgtbl_lookup:
         tlbmiss_restore
         rete
 
-handle_vmalloc_miss:
-        /* Simply do the lookup in init's page table */
+        /* 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
+        stmts   --sp, r0-lr
+        rcall   save_full_context_ex
+        mfsr    r12, SYSREG_ECR
+        mov     r11, sp
+        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                    --- */
 
-        .section .scall.text,"ax",@progbits
+        .org    0x100
 system_call:
 #ifdef CONFIG_PREEMPT
         mask_interrupts
@@ -266,18 +296,6 @@ syscall_exit_work:
         brcc    syscall_exit_cont
         rjmp    enter_monitor_mode
 
-        /* The slow path of the TLB miss handler */
-page_table_not_present:
-page_not_present:
-        tlbmiss_restore
-        sub     sp, 4
-        stmts   --sp, r0-lr
-        rcall   save_full_context_ex
-        mfsr    r12, SYSREG_ECR
-        mov     r11, sp
-        rcall   do_page_fault
-        rjmp    ret_from_exception
-
         /* This function expects to find offending PC in SYSREG_RAR_EX */
         .type   save_full_context_ex, @function
         .align  2