From: Benjamin Herrenschmidt <benh@kernel.crashing.org>
To: linuxppc-dev@ozlabs.org
Subject: [PATCH 11/13] powerpc: Fix 64-bit BookE FP unavailable exceptions
Date: Mon, 5 Mar 2012 13:51:29 +1100 [thread overview]
Message-ID: <1330915891-19523-12-git-send-email-benh@kernel.crashing.org> (raw)
In-Reply-To: <1330915891-19523-1-git-send-email-benh@kernel.crashing.org>
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>
---
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 3de9993..c4c3466 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)
--
1.7.9
next prev parent reply other threads:[~2012-03-05 2:53 UTC|newest]
Thread overview: 14+ messages / expand[flat|nested] mbox.gz Atom feed top
2012-03-05 2:51 [PATCH 00/13 v2] powerpc: Low level spring cleaning Benjamin Herrenschmidt
2012-03-05 2:51 ` [PATCH 01/13] powerpc: Remove legacy iSeries bits from assembly files Benjamin Herrenschmidt
2012-03-05 2:51 ` [PATCH 02/13] powerpc: Use the same interrupt prolog for perfmon as other interrupts Benjamin Herrenschmidt
2012-03-05 2:51 ` [PATCH 03/13] powerpc: Rework runlatch code Benjamin Herrenschmidt
2012-03-05 2:51 ` [PATCH 04/13] powerpc: Improve 64-bit syscall entry/exit Benjamin Herrenschmidt
2012-03-05 2:51 ` [PATCH 05/13] powerpc: Improve behaviour of irq tracing on 64-bit exception entry Benjamin Herrenschmidt
2012-03-05 2:51 ` [PATCH 06/13] powerpc: Disable interrupts in 64-bit kernel FP and vector faults Benjamin Herrenschmidt
2012-03-05 2:51 ` [PATCH 07/13] powerpc: Call do_page_fault() with interrupts off Benjamin Herrenschmidt
2012-03-05 2:51 ` [PATCH 08/13] powerpc: Add support for page fault retry and fatal signals Benjamin Herrenschmidt
2012-03-05 2:51 ` [PATCH 09/13] powerpc/xmon: Add display of soft & hard irq states Benjamin Herrenschmidt
2012-03-05 2:51 ` [PATCH 10/13] powerpc: Fix register clobbering when accumulating stolen time Benjamin Herrenschmidt
2012-03-05 2:51 ` Benjamin Herrenschmidt [this message]
2012-03-05 2:51 ` [PATCH 12/13] powerpc: Replace mfmsr instructions with load from PACA kernel_msr field Benjamin Herrenschmidt
2012-03-05 2:51 ` [PATCH 13/13] powerpc: Rework lazy-interrupt handling Benjamin Herrenschmidt
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