From a546498f3bf9aac311c66f965186373aee2ca0b0 Mon Sep 17 00:00:00 2001 From: Benjamin Herrenschmidt Date: Wed, 7 Mar 2012 16:48:45 +1100 Subject: powerpc: Call do_page_fault() with interrupts off We currently turn interrupts back to their previous state before calling do_page_fault(). This can be annoying when debugging as a bad fault will potentially have lost some processor state before getting into the debugger. We also end up calling some generic code with interrupts enabled such as notify_page_fault() with interrupts enabled, which could be unexpected. This changes our code to behave more like other architectures, and make the assembly entry code call into do_page_faults() with interrupts disabled. They are conditionally re-enabled from within do_page_fault() in the same spot x86 does it. While there, add the might_sleep() test in the case of a successful trylock of the mmap semaphore, again like x86. Also fix a bug in the existing assembly where r12 (_MSR) could get clobbered by C calls (the DTL accounting in the exception common macro and DISABLE_INTS) in some cases. Signed-off-by: Benjamin Herrenschmidt --- v2. Add the r12 clobber fix --- arch/powerpc/kernel/head_fsl_booke.S | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) (limited to 'arch/powerpc/kernel/head_fsl_booke.S') diff --git a/arch/powerpc/kernel/head_fsl_booke.S b/arch/powerpc/kernel/head_fsl_booke.S index d5d78c4..28e6259 100644 --- a/arch/powerpc/kernel/head_fsl_booke.S +++ b/arch/powerpc/kernel/head_fsl_booke.S @@ -319,7 +319,7 @@ interrupt_base: mfspr r4,SPRN_DEAR /* Grab the DEAR, save it, pass arg2 */ andis. r10,r5,(ESR_ILK|ESR_DLK)@h bne 1f - EXC_XFER_EE_LITE(0x0300, handle_page_fault) + EXC_XFER_LITE(0x0300, handle_page_fault) 1: addi r3,r1,STACK_FRAME_OVERHEAD EXC_XFER_EE_LITE(0x0300, CacheLockingException) -- cgit v1.1