powerpc/mm: Update bits used to skip hash_page

We test a number of bits from DSISR/SRR1 before deciding
to call hash_page(). If any of these is set, we go directly
to do_page_fault() as the bit indicate a fault that needs
to be handled there (no hashing needed).

This updates the current open-coded masks to use the new
DSISR definitions.

This *does* change the masks actually used in two ways:

 - We used to test various bits that were defined as "always 0"
in the architecture and could be repurposed for something
else. From now on, we just ignore such bits.

 - We were missing some new bits defined on P9

Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>

diff --git a/arch/powerpc/kernel/exceptions-64s.S b/arch/powerpc/kernel/exceptions-64s.S
index 9029afd1fa2ab2ce231045659abf11ec9eaa32f6..775ad0b77830f65eb1c4242a5909c6238eb6c596 100644 (file)
--- a/arch/powerpc/kernel/exceptions-64s.S
+++ b/arch/powerpc/kernel/exceptions-64s.S
@@ -1477,8 +1477,10 @@ USE_TEXT_SECTION()
  */
        .balign IFETCH_ALIGN_BYTES
 do_hash_page:
-#ifdef CONFIG_PPC_STD_MMU_64
-       andis.  r0,r4,0xa450            /* weird error? */
+       #ifdef CONFIG_PPC_STD_MMU_64
+       lis     r0,DSISR_BAD_FAULT_64S@h
+       ori     r0,r0,DSISR_BAD_FAULT_64S@l
+       and.    r0,r4,r0                /* weird error? */
        bne-    handle_page_fault       /* if not, try to insert a HPTE */
        CURRENT_THREAD_INFO(r11, r1)
        lwz     r0,TI_PREEMPT(r11)      /* If we're in an "NMI" */

diff --git a/arch/powerpc/kernel/head_32.S b/arch/powerpc/kernel/head_32.S
index 067b843a63a94a69f42ce49857292cd1c058cc0b..b1aa0119ad20247acfefccf6a8110560efa337ae 100644 (file)
--- a/arch/powerpc/kernel/head_32.S
+++ b/arch/powerpc/kernel/head_32.S
@@ -388,7 +388,7 @@ DataAccess:
        EXCEPTION_PROLOG
        mfspr   r10,SPRN_DSISR
        stw     r10,_DSISR(r11)
-       andis.  r0,r10,0xa470           /* weird error? */
+       andis.  r0,r10,DSISR_BAD_FAULT_32S@h
        bne     1f                      /* if not, try to put a PTE */
        mfspr   r4,SPRN_DAR             /* into the hash table */
        rlwinm  r3,r10,32-15,21,21      /* DSISR_STORE -> _PAGE_RW */