From: Oliver O'Halloran <oohall@gmail.com>
To: linuxppc-dev@lists.ozlabs.org
Cc: Oliver O'Halloran <oohall@gmail.com>
Subject: [PATCH] powerpc/asm: Mark cr0 as clobbered in mftb()
Date: Thu, 6 Jul 2017 18:46:43 +1000 [thread overview]
Message-ID: <20170706084643.22425-1-oohall@gmail.com> (raw)
The workaround for the CELL timebase bug does not correctly mark cr0 as
being clobbered. This can result in GCC making some poor^W completely
broken optimisations.
Signed-off-by: Oliver O'Halloran <oohall@gmail.com>
---
arch/powerpc/include/asm/reg.h | 2 +-
1 file changed, 1 insertion(+), 1 deletion(-)
diff --git a/arch/powerpc/include/asm/reg.h b/arch/powerpc/include/asm/reg.h
index 7e50e47375d6..a3b6575c7842 100644
--- a/arch/powerpc/include/asm/reg.h
+++ b/arch/powerpc/include/asm/reg.h
@@ -1303,7 +1303,7 @@ static inline void msr_check_and_clear(unsigned long bits)
" .llong 0\n" \
".previous" \
: "=r" (rval) \
- : "i" (CPU_FTR_CELL_TB_BUG), "i" (SPRN_TBRL)); \
+ : "i" (CPU_FTR_CELL_TB_BUG), "i" (SPRN_TBRL) : "cr0"); \
rval;})
#else
#define mftb() ({unsigned long rval; \
--
2.9.4
next reply other threads:[~2017-07-06 8:46 UTC|newest]
Thread overview: 6+ messages / expand[flat|nested] mbox.gz Atom feed top
2017-07-06 8:46 Oliver O'Halloran [this message]
2017-07-10 11:50 ` [PATCH] powerpc/asm: Mark cr0 as clobbered in mftb() Michael Ellerman
2017-07-10 13:43 ` Segher Boessenkool
2017-07-11 2:33 ` Michael Ellerman
2017-07-11 4:02 ` Oliver
2017-07-11 12:48 ` Michael Ellerman
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