sh: TLB protection violation exception optimizations.

This adds a bit of rework to have the TLB protection violations skip the
TLB miss fastpath and go directly in to do_page_fault(), as these require
slow path handling.

Based on an earlier patch by SUGIOKA Toshinobu.

Signed-off-by: Paul Mundt <lethal@linux-sh.org>

1 files changed, 19 insertions, 11 deletions

diff --git a/arch/sh/kernel/cpu/sh3/entry.S b/arch/sh/kernel/cpu/sh3/entry.S
index 3cb531f233f..bbaf2bd118e 100644
--- a/arch/sh/kernel/cpu/sh3/entry.S
+++ b/arch/sh/kernel/cpu/sh3/entry.S
@@ -113,34 +113,33 @@ OFF_TRA	=  (16*4+6*4)
 #if defined(CONFIG_MMU)
         .align  2
 ENTRY(tlb_miss_load)
-        bra     call_dpf
+        bra     call_handle_tlbmiss
          mov    #0, r5
 
         .align  2
 ENTRY(tlb_miss_store)
-        bra     call_dpf
+        bra     call_handle_tlbmiss
          mov    #1, r5
 
         .align  2
 ENTRY(initial_page_write)
-        bra     call_dpf
+        bra     call_handle_tlbmiss
          mov    #1, r5
 
         .align  2
 ENTRY(tlb_protection_violation_load)
-        bra     call_dpf
+        bra     call_do_page_fault
          mov    #0, r5
 
         .align  2
 ENTRY(tlb_protection_violation_store)
-        bra     call_dpf
+        bra     call_do_page_fault
          mov    #1, r5
 
-call_dpf:
+call_handle_tlbmiss:
         mov.l   1f, r0
         mov     r5, r8
         mov.l   @r0, r6
-        mov     r6, r9
         mov.l   2f, r0
         sts     pr, r10
         jsr     @r0
@@ -151,16 +150,25 @@ call_dpf:
          lds    r10, pr
         rts
          nop
-0:      mov.l   3f, r0
-        mov     r9, r6
+0:
         mov     r8, r5
+call_do_page_fault:
+        mov.l   1f, r0
+        mov.l   @r0, r6
+
+        sti
+
+        mov.l   3f, r0
+        mov.l   4f, r1
+        mov     r15, r4
         jmp     @r0
-         mov    r15, r4
+         lds    r1, pr
 
         .align 2
 1:      .long   MMU_TEA
-2:      .long   __do_page_fault
+2:      .long   handle_tlbmiss
 3:      .long   do_page_fault
+4:      .long   ret_from_exception
 
         .align  2
 ENTRY(address_error_load)