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authorJoakim Tjernlund <joakim.tjernlund@transmode.se>2009-11-20 00:21:04 +0000
committerBenjamin Herrenschmidt <benh@kernel.crashing.org>2009-12-09 17:10:36 +1100
commit60e071fee994ff98c37d03a4a7c5a3f8b1e3b8e5 (patch)
tree4b42f796ec84bf1544f4779e5a95713c7253a41d /arch/powerpc/kernel
parentfe11dc3f9628e5393e932567b7e29d35cbbad136 (diff)
downloadtalos-obmc-linux-60e071fee994ff98c37d03a4a7c5a3f8b1e3b8e5.tar.gz
talos-obmc-linux-60e071fee994ff98c37d03a4a7c5a3f8b1e3b8e5.zip
powerpc/8xx: Tag DAR with 0x00f0 to catch buggy instructions.
dcbz, dcbf, dcbi, dcbst and icbi do not set DAR when they cause a DTLB Error. Dectect this by tagging DAR with 0x00f0 at every exception exit that modifies DAR. Test for DAR=0x00f0 in DataTLBError and bail to handle_page_fault(). Signed-off-by: Joakim Tjernlund <Joakim.Tjernlund@transmode.se> Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
Diffstat (limited to 'arch/powerpc/kernel')
-rw-r--r--arch/powerpc/kernel/head_8xx.S15
1 files changed, 14 insertions, 1 deletions
diff --git a/arch/powerpc/kernel/head_8xx.S b/arch/powerpc/kernel/head_8xx.S
index 97bd523a0278..a9f1ace484d5 100644
--- a/arch/powerpc/kernel/head_8xx.S
+++ b/arch/powerpc/kernel/head_8xx.S
@@ -206,6 +206,8 @@ MachineCheck:
EXCEPTION_PROLOG
mfspr r4,SPRN_DAR
stw r4,_DAR(r11)
+ li r5,0x00f0
+ mtspr SPRN_DAR,r5 /* Tag DAR, to be used in DTLB Error */
mfspr r5,SPRN_DSISR
stw r5,_DSISR(r11)
addi r3,r1,STACK_FRAME_OVERHEAD
@@ -222,6 +224,8 @@ DataAccess:
stw r10,_DSISR(r11)
mr r5,r10
mfspr r4,SPRN_DAR
+ li r10,0x00f0
+ mtspr SPRN_DAR,r10 /* Tag DAR, to be used in DTLB Error */
EXC_XFER_EE_LITE(0x300, handle_page_fault)
/* Instruction access exception.
@@ -244,6 +248,8 @@ Alignment:
EXCEPTION_PROLOG
mfspr r4,SPRN_DAR
stw r4,_DAR(r11)
+ li r5,0x00f0
+ mtspr SPRN_DAR,r5 /* Tag DAR, to be used in DTLB Error */
mfspr r5,SPRN_DSISR
stw r5,_DSISR(r11)
addi r3,r1,STACK_FRAME_OVERHEAD
@@ -445,6 +451,7 @@ DataStoreTLBMiss:
* of the MMU.
*/
2: li r11, 0x00f0
+ mtspr SPRN_DAR,r11 /* Tag DAR */
rlwimi r10, r11, 0, 24, 28 /* Set 24-27, clear 28 */
DO_8xx_CPU6(0x3d80, r3)
mtspr SPRN_MD_RPN, r10 /* Update TLB entry */
@@ -485,6 +492,10 @@ DataTLBError:
stw r10, 0(r0)
stw r11, 4(r0)
+ mfspr r10, SPRN_DAR
+ cmpwi cr0, r10, 0x00f0
+ beq- 2f /* must be a buggy dcbX, icbi insn. */
+
mfspr r11, SPRN_DSISR
andis. r11, r11, 0x4800 /* !translation or protection */
bne 2f /* branch if either is set */
@@ -508,7 +519,8 @@ DataTLBError:
* are initialized in mapin_ram(). This will avoid the problem,
* assuming we only use the dcbi instruction on kernel addresses.
*/
- mfspr r10, SPRN_DAR
+
+ /* DAR is in r10 already */
rlwinm r11, r10, 0, 0, 19
ori r11, r11, MD_EVALID
mfspr r10, SPRN_M_CASID
@@ -550,6 +562,7 @@ DataTLBError:
* of the MMU.
*/
li r11, 0x00f0
+ mtspr SPRN_DAR,r11 /* Tag DAR */
rlwimi r10, r11, 0, 24, 28 /* Set 24-27, clear 28 */
DO_8xx_CPU6(0x3d80, r3)
mtspr SPRN_MD_RPN, r10 /* Update TLB entry */
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