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().
Signed-off-by: Yingjoe Chen <[email protected]>
---
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
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 <[email protected]>
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 <[email protected]>
> ---
> 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
> [email protected]
> http://lists.infradead.org/mailman/listinfo/linux-arm-kernel
On Mon, 2015-04-13 at 13:48 +0100, Dave Martin wrote:
> 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 <[email protected]>
>
> 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.
Hi Dave,
Thanks for your review.
I did notice there are __opcode_is_thumb16/32. They need to handle
32bits instruction instead of 16bits only for is_wide_instruction, so I
think using same implementation for them is a different story.
Joe.C
>
> Cheers
> ---Dave
>
> >
> > Signed-off-by: Yingjoe Chen <[email protected]>
> > ---
> > 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
> > [email protected]
> > http://lists.infradead.org/mailman/listinfo/linux-arm-kernel
>
On Mon, Apr 13, 2015 at 10:47:24PM +0800, Yingjoe Chen wrote:
> On Mon, 2015-04-13 at 13:48 +0100, Dave Martin wrote:
> > 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 <[email protected]>
> >
> > 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.
>
> Hi Dave,
>
> Thanks for your review.
>
> I did notice there are __opcode_is_thumb16/32. They need to handle
> 32bits instruction instead of 16bits only for is_wide_instruction, so I
> think using same implementation for them is a different story.
>
> Joe.C
No worries. It can be tidied up some more later if someone finds a good
reason for it.
Cheers
---Dave
On Fri, 2015-04-10 at 22:05 +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().
>
Hi Russell,
Any suggestion about this patch?
Should I put this into your patch system?
Joe.C
> Signed-off-by: Yingjoe Chen <[email protected]>
> ---
> 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);