[PATCH v2 9/9] arm64: Add an override for ID_AA64SMFR0_EL1.FA64
Marc Zyngier
maz at kernel.org
Thu Jun 30 09:05:00 PDT 2022
Add a specific override for ID_AA64SMFR0_EL1.FA64, which
disables the full A64 streaming SVE mode.
Note that no alias is provided for this, as this is already
covered by arm64.nosme, and is only added as a debugging
facility.
Signed-off-by: Marc Zyngier <maz at kernel.org>
---
arch/arm64/kernel/hyp-stub.S | 15 ++++++++-------
arch/arm64/kernel/idreg-override.c | 11 +++++++++++
2 files changed, 19 insertions(+), 7 deletions(-)
diff --git a/arch/arm64/kernel/hyp-stub.S b/arch/arm64/kernel/hyp-stub.S
index d6b0a70a7080..3dcc3272ce16 100644
--- a/arch/arm64/kernel/hyp-stub.S
+++ b/arch/arm64/kernel/hyp-stub.S
@@ -122,17 +122,18 @@ SYM_CODE_START_LOCAL(__finalise_el2)
msr sctlr_el2, x1
isb
- mov x1, #0 // SMCR controls
+ mov x0, #0 // SMCR controls
- mrs_s x2, SYS_ID_AA64SMFR0_EL1
- ubfx x2, x2, #ID_AA64SMFR0_FA64_SHIFT, #1 // Full FP in SM?
- cbz x2, .Lskip_sme_fa64
+ // Full FP in SM?
+ mrs_s x1, SYS_ID_AA64SMFR0_EL1
+ __check_override id_aa64smfr0 ID_AA64SMFR0_FA64_SHIFT 1 .Linit_sme_fa64 .Lskip_sme_fa64
- orr x1, x1, SMCR_ELx_FA64_MASK
+.Linit_sme_fa64:
+ orr x0, x0, SMCR_ELx_FA64_MASK
.Lskip_sme_fa64:
- orr x1, x1, #SMCR_ELx_LEN_MASK // Enable full SME vector
- msr_s SYS_SMCR_EL2, x1 // length for EL1.
+ orr x0, x0, #SMCR_ELx_LEN_MASK // Enable full SME vector
+ msr_s SYS_SMCR_EL2, x0 // length for EL1.
mrs_s x1, SYS_SMIDR_EL1 // Priority mapping supported?
ubfx x1, x1, #SMIDR_EL1_SMPS_SHIFT, #1
diff --git a/arch/arm64/kernel/idreg-override.c b/arch/arm64/kernel/idreg-override.c
index 7cca82639606..aa2a53d0d417 100644
--- a/arch/arm64/kernel/idreg-override.c
+++ b/arch/arm64/kernel/idreg-override.c
@@ -127,6 +127,16 @@ static const struct ftr_set_desc isar2 __initconst = {
},
};
+static const struct ftr_set_desc smfr0 __initconst = {
+ .name = "id_aa64smfr0",
+ .override = &id_aa64smfr0_override,
+ .fields = {
+ /* FA64 is a one bit field... :-/ */
+ { "fa64", ID_AA64SMFR0_FA64_SHIFT, 1, },
+ {}
+ },
+};
+
extern struct arm64_ftr_override kaslr_feature_override;
static const struct ftr_set_desc kaslr __initconst = {
@@ -146,6 +156,7 @@ static const struct ftr_set_desc * const regs[] __initconst = {
&pfr1,
&isar1,
&isar2,
+ &smfr0,
&kaslr,
};
--
2.34.1
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