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authorPaul Mackerras <paulus@samba.org>2008-04-14 13:59:02 +1000
committerPaul Mackerras <paulus@samba.org>2008-04-14 21:11:22 +1000
commit320787c75ccac3189a1b7aae81f0efc1055f6d3a (patch)
treee4e6f029fc4633ef184b9af94189236a6f5ea136 /arch/powerpc/kernel/head_64.S
parentac7c5353b189e10cf5dd27399f64f7b013abffc6 (diff)
[POWERPC] Fix handling of unrecoverable SLB miss interrupts
If an SLB miss interrupt happens while the RI bit of MSR is zero, we can't just return, because RI being zero indicates that SRR0/SRR1 potentially had live values in them, and the process of taking an interrupt overwrites them. This should never happen, but if it does, we try to print a nice oops message. That doesn't work, however, because the code at unrecov_slb assumes that the MMU has been turned on, but we call it with the MMU off (and have done so since the SLB miss handler was rewritten to run without turning the MMU on) -- except on iSeries, where everything runs with the MMU on. This fixes it by adding the necessary code to turn the MMU on if necessary. Signed-off-by: Paul Mackerras <paulus@samba.org>
Diffstat (limited to 'arch/powerpc/kernel/head_64.S')
-rw-r--r--arch/powerpc/kernel/head_64.S18
1 files changed, 17 insertions, 1 deletions
diff --git a/arch/powerpc/kernel/head_64.S b/arch/powerpc/kernel/head_64.S
index d3aee08e681..43a38d89eaf 100644
--- a/arch/powerpc/kernel/head_64.S
+++ b/arch/powerpc/kernel/head_64.S
@@ -621,7 +621,7 @@ END_FW_FTR_SECTION_IFSET(FW_FEATURE_ISERIES)
mtlr r10
andi. r10,r12,MSR_RI /* check for unrecoverable exception */
- beq- unrecov_slb
+ beq- 2f
.machine push
.machine "power4"
@@ -643,6 +643,22 @@ END_FW_FTR_SECTION_IFSET(FW_FEATURE_ISERIES)
rfid
b . /* prevent speculative execution */
+2:
+#ifdef CONFIG_PPC_ISERIES
+BEGIN_FW_FTR_SECTION
+ b unrecov_slb
+END_FW_FTR_SECTION_IFSET(FW_FEATURE_ISERIES)
+#endif /* CONFIG_PPC_ISERIES */
+ mfspr r11,SPRN_SRR0
+ clrrdi r10,r13,32
+ LOAD_HANDLER(r10,unrecov_slb)
+ mtspr SPRN_SRR0,r10
+ mfmsr r10
+ ori r10,r10,MSR_IR|MSR_DR|MSR_RI
+ mtspr SPRN_SRR1,r10
+ rfid
+ b .
+
unrecov_slb:
EXCEPTION_PROLOG_COMMON(0x4100, PACA_EXSLB)
DISABLE_INTS