Messages in this thread Patch in this message | ![/](/images/icornerl.gif) | | Date | Mon, 13 Apr 2015 13:48:39 +0100 | From | Dave Martin <> | Subject | Re: [PATCH] ARM: alignment: Use is_wide_instruction() to check wide instruction |
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On Fri, Apr 10, 2015 at 10:05:41PM +0800, Yingjoe Chen wrote: > > I first notice the comment is incorrect, then I realize there's another > macro which do exactly the same thing. > Tested with hand written userspace program with a few wide instructions > to make sure this still work as expect. > > 8<------------------------------------------------- > do_alignment() is using locally added IS_T32() macro to check if an > instruction is a Thumb-2 32 bit instruction. The macro > is_wide_instruction() is doing the same thing, with slightly faster > implementation. > Change to use is_wide_instruction() in do_alignment() and remove > IS_T32().
Reviewed-by: Dave Martin <Dave.Martin@arm.com>
The existing code is correct, but the comment is indeed wrong. Consolidating this with one of the other existing macros makes sense.
!__opcode_is_thumb16() could also be used here (or is_wide_instruction() redefined in terms of it), but that's not essential.
Cheers ---Dave
> > Signed-off-by: Yingjoe Chen <yingjoe.chen@mediatek.com> > --- > arch/arm/mm/alignment.c | 6 +----- > 1 file changed, 1 insertion(+), 5 deletions(-) > > diff --git a/arch/arm/mm/alignment.c b/arch/arm/mm/alignment.c > index 2c0c541..f8e82f5 100644 > --- a/arch/arm/mm/alignment.c > +++ b/arch/arm/mm/alignment.c > @@ -71,10 +71,6 @@ > > #define BAD_INSTR 0xdeadc0de > > -/* Thumb-2 32 bit format per ARMv7 DDI0406A A6.3, either f800h,e800h,f800h */ > -#define IS_T32(hi16) \ > - (((hi16) & 0xe000) == 0xe000 && ((hi16) & 0x1800)) > - > static unsigned long ai_user; > static unsigned long ai_sys; > static void *ai_sys_last_pc; > @@ -770,7 +766,7 @@ do_alignment(unsigned long addr, unsigned int fsr, struct pt_regs *regs) > tinstr = __mem_to_opcode_thumb16(tinstr); > if (!fault) { > if (cpu_architecture() >= CPU_ARCH_ARMv7 && > - IS_T32(tinstr)) { > + is_wide_instruction(tinstr)) { > /* Thumb-2 32-bit */ > u16 tinst2 = 0; > fault = probe_kernel_address(ptr + 1, tinst2); > -- > 1.8.1.1.dirty > > > _______________________________________________ > linux-arm-kernel mailing list > linux-arm-kernel@lists.infradead.org > http://lists.infradead.org/mailman/listinfo/linux-arm-kernel
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