Minki/linux
1
0
Fork 1
mirror of https://github.com/torvalds/linux.git synced 2024-11-26 06:02:05 +00:00
Code Issues Packages Projects Releases Wiki Activity

arm64: Generalise msr_s/mrs_s operations

Browse Source 
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>
This commit is contained in:
Suzuki K. Poulose 2015-07-22 11:38:14 +01:00 committed by Will Deacon
parent 91a5cefa2f
commit 9ded63aaf8
1 changed files with 15 additions and 5 deletions
Show Stats Download Patch File Download Diff File Expand all files Collapse all files

20
arch/arm64/include/asm/sysreg.h
View File

@ -23,8 +23,18 @@
#define SCTLR_EL1_CP15BEN (0x1 << 5)
#define SCTLR_EL1_SED (0x1 << 8)
/*
* ARMv8 ARM reserves the following encoding for system registers:
* (Ref: ARMv8 ARM, Section: "System instruction class encoding overview",
* C5.2, version:ARM DDI 0487A.f)
* [20-19] : Op0
* [18-16] : Op1
* [15-12] : CRn
* [11-8] : CRm
* [7-5] : Op2
*/
#define sys_reg(op0, op1, crn, crm, op2) \
((((op0)-2)<<19)|((op1)<<16)|((crn)<<12)|((crm)<<8)|((op2)<<5))
((((op0)&3)<<19)|((op1)<<16)|((crn)<<12)|((crm)<<8)|((op2)<<5))
#ifdef __ASSEMBLY__
@ -34,11 +44,11 @@
.equ __reg_num_xzr, 31
.macro mrs_s, rt, sreg
.inst 0xd5300000|(\sreg)|(__reg_num_\rt)
.inst 0xd5200000|(\sreg)|(__reg_num_\rt)
.endm
.macro msr_s, sreg, rt
.inst 0xd5100000|(\sreg)|(__reg_num_\rt)
.inst 0xd5000000|(\sreg)|(__reg_num_\rt)
.endm
#else
@ -50,11 +60,11 @@ asm(
" .equ __reg_num_xzr, 31\n"
"\n"
" .macro mrs_s, rt, sreg\n"
" .inst 0xd5300000|(\\sreg)|(__reg_num_\\rt)\n"
" .inst 0xd5200000|(\\sreg)|(__reg_num_\\rt)\n"
" .endm\n"
"\n"
" .macro msr_s, sreg, rt\n"
" .inst 0xd5100000|(\\sreg)|(__reg_num_\\rt)\n"
" .inst 0xd5000000|(\\sreg)|(__reg_num_\\rt)\n"
" .endm\n"
);