| Message ID | 20220627151412.1496361-5-maz@kernel.org (mailing list archive) |
|---|---|
| State | New, archived |
| Headers | show |
| Series | arm64: Disabling SVE/SME from the command-line | expand |
On Mon, Jun 27, 2022 at 04:14:10PM +0100, Marc Zyngier wrote: > Checking for a feature being supported from assembly code is > a bit tedious if we need to factor in the idreg override. > > Since we already have such code written for forcing nVHE, move > the whole thing into a macro. This heavily relies on the override > structure being called foo_override for foo_el1. Reviwed-by: Mark Brown <broonie@kernel.org>
On Tue, 28 Jun 2022 12:28:32 +0100, Mark Brown <broonie@kernel.org> wrote: > > On Mon, Jun 27, 2022 at 04:14:10PM +0100, Marc Zyngier wrote: > > Checking for a feature being supported from assembly code is > > a bit tedious if we need to factor in the idreg override. > > > > Since we already have such code written for forcing nVHE, move > > the whole thing into a macro. This heavily relies on the override > > structure being called foo_override for foo_el1. > > Reviwed-by: Mark Brown <broonie@kernel.org> Reviewed? M.
On Wed, Jun 29, 2022 at 04:46:55PM +0100, Marc Zyngier wrote: > On Tue, 28 Jun 2022 12:28:32 +0100, > Mark Brown <broonie@kernel.org> wrote: > > > > On Mon, Jun 27, 2022 at 04:14:10PM +0100, Marc Zyngier wrote: > > > Checking for a feature being supported from assembly code is > > > a bit tedious if we need to factor in the idreg override. > > > > > > Since we already have such code written for forcing nVHE, move > > > the whole thing into a macro. This heavily relies on the override > > > structure being called foo_override for foo_el1. > > > > Reviwed-by: Mark Brown <broonie@kernel.org> > > Reviewed? Yes, sorry. Reviewed-by: Mark Brown <broonie@kernel.org>
diff --git a/arch/arm64/kernel/hyp-stub.S b/arch/arm64/kernel/hyp-stub.S index 26206e53e0c9..4a02a73650db 100644 --- a/arch/arm64/kernel/hyp-stub.S +++ b/arch/arm64/kernel/hyp-stub.S @@ -16,6 +16,23 @@ #include <asm/ptrace.h> #include <asm/virt.h> +.macro check_override idreg, fld, pass, fail + mrs x1, \idreg\()_el1 + ubfx x1, x1, #\fld, #4 + cbz x1, \fail + + adr_l x1, \idreg\()_override + ldr x2, [x1, FTR_OVR_VAL_OFFSET] + ldr x1, [x1, FTR_OVR_MASK_OFFSET] + ubfx x2, x2, #\fld, #4 + ubfx x1, x1, #\fld, #4 + cmp x1, xzr + and x2, x2, x1 + csinv x2, x2, xzr, ne + cbnz x2, \pass + b \fail +.endm + .text .pushsection .hyp.text, "ax" @@ -80,20 +97,7 @@ SYM_CODE_START_LOCAL(__finalise_el2) tbnz x1, #0, 1f // Needs to be VHE capable, obviously - mrs x1, id_aa64mmfr1_el1 - ubfx x1, x1, #ID_AA64MMFR1_VHE_SHIFT, #4 - cbz x1, 1f - - // Check whether VHE is disabled from the command line - adr_l x1, id_aa64mmfr1_override - ldr x2, [x1, FTR_OVR_VAL_OFFSET] - ldr x1, [x1, FTR_OVR_MASK_OFFSET] - ubfx x2, x2, #ID_AA64MMFR1_VHE_SHIFT, #4 - ubfx x1, x1, #ID_AA64MMFR1_VHE_SHIFT, #4 - cmp x1, xzr - and x2, x2, x1 - csinv x2, x2, xzr, ne - cbnz x2, 2f + check_override id_aa64mmfr1 ID_AA64MMFR1_VHE_SHIFT 2f 1f 1: mov_q x0, HVC_STUB_ERR eret
Checking for a feature being supported from assembly code is a bit tedious if we need to factor in the idreg override. Since we already have such code written for forcing nVHE, move the whole thing into a macro. This heavily relies on the override structure being called foo_override for foo_el1. No functional change. Signed-off-by: Marc Zyngier <maz@kernel.org> --- arch/arm64/kernel/hyp-stub.S | 32 ++++++++++++++++++-------------- 1 file changed, 18 insertions(+), 14 deletions(-)