From mboxrd@z Thu Jan 1 00:00:00 1970 From: marc.zyngier@arm.com (Marc Zyngier) Date: Thu, 24 Dec 2015 11:12:11 +0000 Subject: [PATCH 03/31] arm64: Add macros to read/write system registers In-Reply-To: <1450955559-15639-1-git-send-email-marc.zyngier@arm.com> References: <1450955559-15639-1-git-send-email-marc.zyngier@arm.com> Message-ID: <1450955559-15639-4-git-send-email-marc.zyngier@arm.com> To: linux-arm-kernel@lists.infradead.org List-Id: linux-arm-kernel.lists.infradead.org From: Mark Rutland Rather than crafting custom macros for reading/writing each system register provide generics accessors, read_sysreg and write_sysreg, for this purpose. Signed-off-by: Mark Rutland Acked-by: Catalin Marinas Cc: Suzuki Poulose Cc: Will Deacon Signed-off-by: Marc Zyngier --- arch/arm64/include/asm/sysreg.h | 21 +++++++++++++++++++++ 1 file changed, 21 insertions(+) diff --git a/arch/arm64/include/asm/sysreg.h b/arch/arm64/include/asm/sysreg.h index d48ab5b..4aeebec 100644 --- a/arch/arm64/include/asm/sysreg.h +++ b/arch/arm64/include/asm/sysreg.h @@ -20,6 +20,8 @@ #ifndef __ASM_SYSREG_H #define __ASM_SYSREG_H +#include + #include /* @@ -208,6 +210,8 @@ #else +#include + asm( " .irp num,0,1,2,3,4,5,6,7,8,9,10,11,12,13,14,15,16,17,18,19,20,21,22,23,24,25,26,27,28,29,30\n" " .equ __reg_num_x\\num, \\num\n" @@ -232,6 +236,23 @@ static inline void config_sctlr_el1(u32 clear, u32 set) val |= set; asm volatile("msr sctlr_el1, %0" : : "r" (val)); } + +/* + * Unlike read_cpuid, calls to read_sysreg are never expected to be + * optimized away or replaced with synthetic values. + */ +#define read_sysreg(r) ({ \ + u64 __val; \ + asm volatile("mrs %0, " __stringify(r) : "=r" (__val)); \ + __val; \ +}) + +#define write_sysreg(v, r) do { \ + u64 __val = (u64)v; \ + asm volatile("msr " __stringify(r) ", %0" \ + : : "r" (__val)); \ +} while (0) + #endif #endif /* __ASM_SYSREG_H */ -- 2.1.4