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| author | Benjamin Herrenschmidt <benh@kernel.crashing.org> | 2012-03-05 10:55:04 +1100 |
|---|---|---|
| committer | Benjamin Herrenschmidt <benh@kernel.crashing.org> | 2012-03-09 10:55:18 +1100 |
| commit | 9424fabf8617c15e18a5ffd29bc3bcfa36620473 (patch) | |
| tree | 6ce26cef57e7a3b60507b823191afed84d3f36a4 | |
| parent | 990118c84b3e90b2b5354b6e2acd961044d7fa12 (diff) | |
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>
| -rw-r--r-- | arch/powerpc/kernel/exceptions-64e.S | 13 |
1 files changed, 7 insertions, 6 deletions
diff --git a/arch/powerpc/kernel/exceptions-64e.S b/arch/powerpc/kernel/exceptions-64e.S index 3de9993c5c65..c4c34665c221 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) |