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authorMahesh Salgaonkar <mahesh@linux.vnet.ibm.com>2014-03-11 10:56:18 +0530
committerBenjamin Herrenschmidt <benh@kernel.crashing.org>2014-03-24 10:16:09 +1100
commitd410ae2126481a74bc5be4a6242c4a232c19a984 (patch)
tree87e14bf51dfa65e3eac3f53528fb6036b0f46de6
parent422b9b9684db3c511e65c91842275c43f5910ae9 (diff)
powerpc/book3s: Fix CFAR clobbering issue in machine check handler.
While checking powersaving mode in machine check handler at 0x200, we clobber CFAR register. Fix it by saving and restoring it during beq/bgt. Signed-off-by: Mahesh Salgaonkar <mahesh@linux.vnet.ibm.com> Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
-rw-r--r--arch/powerpc/include/asm/exception-64s.h8
-rw-r--r--arch/powerpc/kernel/exceptions-64s.S5
2 files changed, 13 insertions, 0 deletions
diff --git a/arch/powerpc/include/asm/exception-64s.h b/arch/powerpc/include/asm/exception-64s.h
index 66830618cc19..aeaa56cd9b54 100644
--- a/arch/powerpc/include/asm/exception-64s.h
+++ b/arch/powerpc/include/asm/exception-64s.h
@@ -147,6 +147,14 @@ BEGIN_FTR_SECTION_NESTED(943) \
END_FTR_SECTION_NESTED(ftr,ftr,943)
/*
+ * Set an SPR from a register if the CPU has the given feature
+ */
+#define OPT_SET_SPR(ra, spr, ftr) \
+BEGIN_FTR_SECTION_NESTED(943) \
+ mtspr spr,ra; \
+END_FTR_SECTION_NESTED(ftr,ftr,943)
+
+/*
* Save a register to the PACA if the CPU has the given feature
*/
#define OPT_SAVE_REG_TO_PACA(offset, ra, ftr) \
diff --git a/arch/powerpc/kernel/exceptions-64s.S b/arch/powerpc/kernel/exceptions-64s.S
index 38d507306a11..4c34c3c827ad 100644
--- a/arch/powerpc/kernel/exceptions-64s.S
+++ b/arch/powerpc/kernel/exceptions-64s.S
@@ -164,13 +164,18 @@ BEGIN_FTR_SECTION
*/
mfspr r13,SPRN_SRR1
rlwinm. r13,r13,47-31,30,31
+ OPT_GET_SPR(r13, SPRN_CFAR, CPU_FTR_CFAR)
beq 9f
+ mfspr r13,SPRN_SRR1
+ rlwinm. r13,r13,47-31,30,31
/* waking up from powersave (nap) state */
cmpwi cr1,r13,2
/* Total loss of HV state is fatal. let's just stay stuck here */
+ OPT_GET_SPR(r13, SPRN_CFAR, CPU_FTR_CFAR)
bgt cr1,.
9:
+ OPT_SET_SPR(r13, SPRN_CFAR, CPU_FTR_CFAR)
END_FTR_SECTION_IFSET(CPU_FTR_HVMODE | CPU_FTR_ARCH_206)
#endif /* CONFIG_PPC_P7_NAP */
EXCEPTION_PROLOG_0(PACA_EXMC)