| Message ID | f73e6deb1bef9696661a62498ee5a56ac9a389ce.1708005130.git.geert+renesas@glider.be (mailing list archive) |
|---|---|
| State | New, archived |
| Headers | show |
| Series | [v2] ARM: ptrace: Use bitfield helpers | expand |
Sorry for the noise, can't resist... I am replying only because I wasn't aware of bitfield.h and useful helpers there. Thank you ;) On 02/15, Geert Uytterhoeven wrote: > > #ifndef __ASSEMBLY__ > +#include <linux/bitfield.h> > #include <linux/types.h> > > struct pt_regs { > @@ -35,8 +36,8 @@ struct svc_pt_regs { > > #ifndef CONFIG_CPU_V7M > #define isa_mode(regs) \ > - ((((regs)->ARM_cpsr & PSR_J_BIT) >> (__ffs(PSR_J_BIT) - 1)) | \ > - (((regs)->ARM_cpsr & PSR_T_BIT) >> (__ffs(PSR_T_BIT)))) > + (FIELD_GET(PSR_J_BIT, (regs)->ARM_cpsr) << 1 | \ > + FIELD_GET(PSR_T_BIT, (regs)->ARM_cpsr)) Reviewed-by: Oleg Nesterov <oleg@redhat.com>
diff --git a/arch/arm/include/asm/ptrace.h b/arch/arm/include/asm/ptrace.h index 7f44e88d1f25bcc5..14a38cc67e0bc966 100644 --- a/arch/arm/include/asm/ptrace.h +++ b/arch/arm/include/asm/ptrace.h @@ -10,6 +10,7 @@ #include <uapi/asm/ptrace.h> #ifndef __ASSEMBLY__ +#include <linux/bitfield.h> #include <linux/types.h> struct pt_regs { @@ -35,8 +36,8 @@ struct svc_pt_regs { #ifndef CONFIG_CPU_V7M #define isa_mode(regs) \ - ((((regs)->ARM_cpsr & PSR_J_BIT) >> (__ffs(PSR_J_BIT) - 1)) | \ - (((regs)->ARM_cpsr & PSR_T_BIT) >> (__ffs(PSR_T_BIT)))) + (FIELD_GET(PSR_J_BIT, (regs)->ARM_cpsr) << 1 | \ + FIELD_GET(PSR_T_BIT, (regs)->ARM_cpsr)) #else #define isa_mode(regs) 1 /* Thumb */ #endif
The isa_mode() macro extracts two fields, and recombines them into a single value. Make this more obvious by using the FIELD_GET() helper, and shifting the result into its final resting place. Signed-off-by: Geert Uytterhoeven <geert+renesas@glider.be> --- No changes in generated assembler code. v2: - Drop irrelevant comment about non-existing off-by-one error, - Remove unnecessary parens. --- arch/arm/include/asm/ptrace.h | 5 +++-- 1 file changed, 3 insertions(+), 2 deletions(-)