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Commit 3600c2fd authored by Mark Rutland's avatar Mark Rutland Committed by Marc Zyngier
Browse files

arm64: Add macros to read/write system registers 



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: default avatarMark Rutland <mark.rutland@arm.com>
Acked-by: default avatarCatalin Marinas <catalin.marinas@arm.com>
Cc: Suzuki Poulose <suzuki.poulose@arm.com>
Cc: Will Deacon <will.deacon@arm.com>
Signed-off-by: default avatarMarc Zyngier <marc.zyngier@arm.com>
parent b19e6892

arch/arm64/include/asm/sysreg.h

+21 −0
Original line number Diff line number Diff line
@@ -20,6 +20,8 @@ 
#ifndef __ASM_SYSREG_H

#define __ASM_SYSREG_H



#include <linux/stringify.h>



#include <asm/opcodes.h>



/*
@@ -208,6 +210,8 @@ 


#else



#include <linux/types.h>



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 */