arm64: Generalise msr_s/mrs_s operations
authorSuzuki K. Poulose <suzuki.poulose@arm.com>
Wed, 22 Jul 2015 10:38:14 +0000 (11:38 +0100)
committerWill Deacon <will.deacon@arm.com>
Mon, 27 Jul 2015 10:08:41 +0000 (11:08 +0100)
commit9ded63aaf83eba76e1a54ac02581c2badc497f1a
tree84adaf6e11adde05c2c1c4d3525efe8822ab9af2
parent91a5cefa2f98bdd3404c2fba57048c4fa225cc37
arm64: Generalise msr_s/mrs_s operations

The system register encoding generated by sys_reg() works only
for MRS/MSR(Register) operations, as we hardcode Bit20 to 1 in
mrs_s/msr_s mask. This makes it unusable for generating instructions
accessing registers with Op0 < 2(e.g, PSTATE.x with Op0=0).

As per ARMv8 ARM, (Ref: ARMv8 ARM, Section: "System instruction class
encoding overview", C5.2, version:ARM DDI 0487A.f), the instruction
encoding reserves bits [20-19] for Op0.

This patch generalises the sys_reg, mrs_s and msr_s macros, so that
we could use them to access any of the supported system register.

Cc: James Morse <james.morse@arm.com>
Cc: Catalin Marinas <catalin.marinas@arm.com>
Signed-off-by: Suzuki K. Poulose <suzuki.poulose@arm.com>
Reviewed-by: Catalin Marinas <catalin.marinas@arm.com>
Signed-off-by: Will Deacon <will.deacon@arm.com>
arch/arm64/include/asm/sysreg.h