| Message ID | 1473419765-3437-2-git-send-email-will.deacon@arm.com |
|---|---|
| State | New |
| Headers | show |
On Fri, Sep 09, 2016 at 12:16:00PM +0100, Will Deacon wrote: > Similar to our {read,write}_sysreg accessors for architected, named > system registers, this patch introduces {read,write}_sysreg_s variants > that can take arbitrary sys_reg output and therefore access IMPDEF > registers or registers that unsupported by binutils. > > Signed-off-by: Will Deacon <will.deacon@arm.com> > --- > arch/arm64/include/asm/cputype.h | 6 +----- > arch/arm64/include/asm/sysreg.h | 16 ++++++++++++++++ > 2 files changed, 17 insertions(+), 5 deletions(-) > +#define write_sysreg_s(v, r) do { \ > + u64 __val = (u64)v; \ > + asm volatile("msr_s " __stringify(r) ", %0" \ > + : : "r" (__val)); \ > +} while (0) As with my patches, can we please make write_sysreg_s allow the zero register? i.e. use the "%x0" tempate and "rZ" constraint. The mrs_s asm template should handle that correctly. With that: Reviewed-by: Mark Rutland <mark.rutland@arm.com> Thanks, Mark. _______________________________________________ linux-arm-kernel mailing list linux-arm-kernel@lists.infradead.org http://lists.infradead.org/mailman/listinfo/linux-arm-kernel
diff --git a/arch/arm64/include/asm/cputype.h b/arch/arm64/include/asm/cputype.h index 9d9fd4b9a72e..26a68ddb11c1 100644 --- a/arch/arm64/include/asm/cputype.h +++ b/arch/arm64/include/asm/cputype.h @@ -93,11 +93,7 @@ #include <asm/sysreg.h> -#define read_cpuid(reg) ({ \ - u64 __val; \ - asm("mrs_s %0, " __stringify(SYS_ ## reg) : "=r" (__val)); \ - __val; \ -}) +#define read_cpuid(reg) read_sysreg_s(SYS_ ## reg) /* * The CPU ID never changes at run time, so we might as well tell the diff --git a/arch/arm64/include/asm/sysreg.h b/arch/arm64/include/asm/sysreg.h index cc06794b7346..10d76d417d17 100644 --- a/arch/arm64/include/asm/sysreg.h +++ b/arch/arm64/include/asm/sysreg.h @@ -279,6 +279,22 @@ static inline void config_sctlr_el1(u32 clear, u32 set) : : "r" (__val)); \ } while (0) +/* + * For registers without architectural names, or simply unsupported by + * GAS. + */ +#define read_sysreg_s(r) ({ \ + u64 __val; \ + asm volatile("mrs_s %0, " __stringify(r) : "=r" (__val)); \ + __val; \ +}) + +#define write_sysreg_s(v, r) do { \ + u64 __val = (u64)v; \ + asm volatile("msr_s " __stringify(r) ", %0" \ + : : "r" (__val)); \ +} while (0) + #endif #endif /* __ASM_SYSREG_H */
Similar to our {read,write}_sysreg accessors for architected, named system registers, this patch introduces {read,write}_sysreg_s variants that can take arbitrary sys_reg output and therefore access IMPDEF registers or registers that unsupported by binutils. Signed-off-by: Will Deacon <will.deacon@arm.com> --- arch/arm64/include/asm/cputype.h | 6 +----- arch/arm64/include/asm/sysreg.h | 16 ++++++++++++++++ 2 files changed, 17 insertions(+), 5 deletions(-) -- 2.1.4 _______________________________________________ linux-arm-kernel mailing list linux-arm-kernel@lists.infradead.org http://lists.infradead.org/mailman/listinfo/linux-arm-kernel