On Wed, Sep 01, 2021 at 09:14:02PM +0000, Raghavendra Rao Ananta wrote:
> For register names that are unsupported by the assembler or the ones
> without architectural names, add the macros write_sysreg_s and
> read_sysreg_s to support them.
>
> The functionality is derived from kvm-unit-tests and kernel's
> arch/arm64/include/asm/sysreg.h.
>
> Signed-off-by: Raghavendra Rao Ananta <rananta@xxxxxxxxxx>
Would it be possible to just include <asm/sysreg.h>? See
tools/arch/arm64/include/asm/sysreg.h
> ---
> .../selftests/kvm/include/aarch64/processor.h | 61 +++++++++++++++++++
> 1 file changed, 61 insertions(+)
>
> diff --git a/tools/testing/selftests/kvm/include/aarch64/processor.h b/tools/testing/selftests/kvm/include/aarch64/processor.h
> index 3cbaf5c1e26b..082cc97ad8d3 100644
> --- a/tools/testing/selftests/kvm/include/aarch64/processor.h
> +++ b/tools/testing/selftests/kvm/include/aarch64/processor.h
> @@ -118,6 +118,67 @@ void vm_install_exception_handler(struct kvm_vm *vm,
> void vm_install_sync_handler(struct kvm_vm *vm,
> int vector, int ec, handler_fn handler);
>
> +/*
> + * 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 Op0_shift 19
> +#define Op0_mask 0x3
> +#define Op1_shift 16
> +#define Op1_mask 0x7
> +#define CRn_shift 12
> +#define CRn_mask 0xf
> +#define CRm_shift 8
> +#define CRm_mask 0xf
> +#define Op2_shift 5
> +#define Op2_mask 0x7
> +
> +/*
> + * When accessed from guests, the ARM64_SYS_REG() doesn't work since it
> + * generates a different encoding for additional KVM processing, and is
> + * only suitable for userspace to access the register via ioctls.
> + * Hence, define a 'pure' sys_reg() here to generate the encodings as per spec.
> + */
> +#define sys_reg(op0, op1, crn, crm, op2) \
> + (((op0) << Op0_shift) | ((op1) << Op1_shift) | \
> + ((crn) << CRn_shift) | ((crm) << CRm_shift) | \
> + ((op2) << Op2_shift))
> +
> +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 .L__reg_num_x\\num, \\num\n"
> +" .endr\n"
> +" .equ .L__reg_num_xzr, 31\n"
> +"\n"
> +" .macro mrs_s, rt, sreg\n"
> +" .inst 0xd5200000|(\\sreg)|(.L__reg_num_\\rt)\n"
> +" .endm\n"
> +"\n"
> +" .macro msr_s, sreg, rt\n"
> +" .inst 0xd5000000|(\\sreg)|(.L__reg_num_\\rt)\n"
> +" .endm\n"
> +);
> +
> +/*
> + * read_sysreg_s() and write_sysreg_s()'s 'reg' has to be encoded via sys_reg()
> + */
> +#define read_sysreg_s(reg) ({ \
> + u64 __val; \
> + asm volatile("mrs_s %0, "__stringify(reg) : "=r" (__val)); \
> + __val; \
> +})
> +
> +#define write_sysreg_s(reg, val) do { \
> + u64 __val = (u64)val; \
> + asm volatile("msr_s "__stringify(reg) ", %x0" : : "rZ" (__val));\
> +} while (0)
> +
> #define write_sysreg(reg, val) \
> ({ \
> u64 __val = (u64)(val); \
> --
> 2.33.0.153.gba50c8fa24-goog
>
