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authorBenjamin Herrenschmidt <benh@kernel.crashing.org>2012-03-05 10:55:04 +1100
committerBenjamin Herrenschmidt <benh@kernel.crashing.org>2012-03-09 10:55:18 +1100
commit9424fabf8617c15e18a5ffd29bc3bcfa36620473 (patch)
tree6ce26cef57e7a3b60507b823191afed84d3f36a4 /arch
parent990118c84b3e90b2b5354b6e2acd961044d7fa12 (diff)
downloadlinaro-lsk-9424fabf8617c15e18a5ffd29bc3bcfa36620473.tar.gz
powerpc: Fix 64-bit BookE FP unavailable exceptions
We were using CR0.EQ after EXCEPTION_COMMON, hoping it still contained whether we came from userspace or kernel space. However, under some circumstances, EXCEPTION_COMMON will call C code and clobber non-volatile registers, so we really need to re-load the previous MSR from the stackframe and re-test. While there, invert the condition to make the fast path more obvious and remove the BUG_OPCODE which was a debugging leftover and call .ret_from_except as we should. Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
Diffstat (limited to 'arch')
-rw-r--r--arch/powerpc/kernel/exceptions-64e.S13
1 files changed, 7 insertions, 6 deletions
diff --git a/arch/powerpc/kernel/exceptions-64e.S b/arch/powerpc/kernel/exceptions-64e.S
index 3de9993c5c6..c4c34665c22 100644
--- a/arch/powerpc/kernel/exceptions-64e.S
+++ b/arch/powerpc/kernel/exceptions-64e.S
@@ -353,15 +353,16 @@ interrupt_end_book3e:
NORMAL_EXCEPTION_PROLOG(0x800, PROLOG_ADDITION_NONE)
/* we can probably do a shorter exception entry for that one... */
EXCEPTION_COMMON(0x800, PACA_EXGEN, INTS_KEEP)
- bne 1f /* if from user, just load it up */
- INTS_DISABLE_ALL
+ ld r12,_MSR(r1)
+ andi. r0,r12,MSR_PR;
+ beq- 1f
+ bl .load_up_fpu
+ b fast_exception_return
+1: INTS_DISABLE_ALL
bl .save_nvgprs
addi r3,r1,STACK_FRAME_OVERHEAD
bl .kernel_fp_unavailable_exception
- BUG_OPCODE
-1: ld r12,_MSR(r1)
- bl .load_up_fpu
- b fast_exception_return
+ b .ret_from_except
/* Decrementer Interrupt */
MASKABLE_EXCEPTION(0x900, decrementer, .timer_interrupt, ACK_DEC)