powerpc/603: don't handle PAGE_ACCESSED in TLB miss handlers.

PAGE_ACCESSED is only needed for CONFIG_SWAP. When CONFIG_SWAP
is not set, just ignore it. If CONFIG_SWAP is set and PAGE_ACCESSED
is not, let's take a minor fault.

Signed-off-by: Christophe Leroy <christophe.leroy@c-s.fr>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>

diff --git a/arch/powerpc/kernel/head_32.S b/arch/powerpc/kernel/head_32.S
index 6b5cb75..fdb587c 100644 (file)
--- a/arch/powerpc/kernel/head_32.S
+++ b/arch/powerpc/kernel/head_32.S
@@ -503,7 +503,11 @@ InstructionTLBMiss:
        cmplw   0,r1,r3
 #endif
        mfspr   r2, SPRN_SPRG_PGDIR
+#ifdef CONFIG_SWAP
+       li      r1,_PAGE_PRESENT | _PAGE_ACCESSED | _PAGE_EXEC
+#else
        li      r1,_PAGE_PRESENT | _PAGE_EXEC
+#endif
 #if defined(CONFIG_MODULES) || defined(CONFIG_DEBUG_PAGEALLOC)
        bge-    112f
        lis     r2, (swapper_pg_dir - PAGE_OFFSET)@ha   /* if kernel address, use */
@@ -517,12 +521,6 @@ InstructionTLBMiss:
        lwz     r0,0(r2)                /* get linux-style pte */
        andc.   r1,r1,r0                /* check access & ~permission */
        bne-    InstructionAddressInvalid /* return if access not permitted */
-       ori     r0,r0,_PAGE_ACCESSED    /* set _PAGE_ACCESSED in pte */
-       /*
-        * NOTE! We are assuming this is not an SMP system, otherwise
-        * we would need to update the pte atomically with lwarx/stwcx.
-        */
-       stw     r0,0(r2)                /* update PTE (accessed bit) */
        /* Convert linux-style PTE to low word of PPC-style PTE */
        rlwimi  r0,r0,32-1,30,30        /* _PAGE_USER -> PP msb */
        ori     r1, r1, 0xe05           /* clear out reserved bits */
@@ -571,7 +569,11 @@ DataLoadTLBMiss:
        lis     r1,PAGE_OFFSET@h                /* check if kernel address */
        cmplw   0,r1,r3
        mfspr   r2, SPRN_SPRG_PGDIR
+#ifdef CONFIG_SWAP
+       li      r1, _PAGE_PRESENT | _PAGE_ACCESSED
+#else
        li      r1, _PAGE_PRESENT
+#endif
        bge-    112f
        lis     r2, (swapper_pg_dir - PAGE_OFFSET)@ha   /* if kernel address, use */
        addi    r2, r2, (swapper_pg_dir - PAGE_OFFSET)@l        /* kernel page table */
@@ -583,12 +585,10 @@ DataLoadTLBMiss:
        lwz     r0,0(r2)                /* get linux-style pte */
        andc.   r1,r1,r0                /* check access & ~permission */
        bne-    DataAddressInvalid      /* return if access not permitted */
-       ori     r0,r0,_PAGE_ACCESSED    /* set _PAGE_ACCESSED in pte */
        /*
         * NOTE! We are assuming this is not an SMP system, otherwise
         * we would need to update the pte atomically with lwarx/stwcx.
         */
-       stw     r0,0(r2)                /* update PTE (accessed bit) */
        /* Convert linux-style PTE to low word of PPC-style PTE */
        rlwinm  r1,r0,32-10,31,31       /* _PAGE_RW -> PP lsb */
        rlwimi  r0,r0,32-1,30,30        /* _PAGE_USER -> PP msb */
@@ -649,7 +649,11 @@ DataStoreTLBMiss:
        lis     r1,PAGE_OFFSET@h                /* check if kernel address */
        cmplw   0,r1,r3
        mfspr   r2, SPRN_SPRG_PGDIR
-       li      r1, _PAGE_RW | _PAGE_PRESENT /* access flags */
+#ifdef CONFIG_SWAP
+       li      r1, _PAGE_RW | _PAGE_PRESENT | _PAGE_ACCESSED
+#else
+       li      r1, _PAGE_RW | _PAGE_PRESENT
+#endif
        bge-    112f
        lis     r2, (swapper_pg_dir - PAGE_OFFSET)@ha   /* if kernel address, use */
        addi    r2, r2, (swapper_pg_dir - PAGE_OFFSET)@l        /* kernel page table */
@@ -661,12 +665,10 @@ DataStoreTLBMiss:
        lwz     r0,0(r2)                /* get linux-style pte */
        andc.   r1,r1,r0                /* check access & ~permission */
        bne-    DataAddressInvalid      /* return if access not permitted */
-       ori     r0,r0,_PAGE_ACCESSED
        /*
         * NOTE! We are assuming this is not an SMP system, otherwise
         * we would need to update the pte atomically with lwarx/stwcx.
         */
-       stw     r0,0(r2)                /* update PTE (accessed/dirty bits) */
        /* Convert linux-style PTE to low word of PPC-style PTE */
        rlwimi  r0,r0,32-1,30,30        /* _PAGE_USER -> PP msb */
        li      r1,0xe05                /* clear out reserved bits & PP lsb */