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-rw-r--r--arch/arm64/kernel/cpufeature.c47
1 files changed, 47 insertions, 0 deletions
diff --git a/arch/arm64/kernel/cpufeature.c b/arch/arm64/kernel/cpufeature.c
index 0f2d7ddd69ae..082b3f48cbfd 100644
--- a/arch/arm64/kernel/cpufeature.c
+++ b/arch/arm64/kernel/cpufeature.c
@@ -581,6 +581,12 @@ static const struct arm64_ftr_bits ftr_zcr[] = {
ARM64_FTR_END,
};
+static const struct arm64_ftr_bits ftr_smcr[] = {
+ ARM64_FTR_BITS(FTR_HIDDEN, FTR_NONSTRICT, FTR_LOWER_SAFE,
+ SMCR_ELx_LEN_SHIFT, SMCR_ELx_LEN_SIZE, 0), /* LEN */
+ ARM64_FTR_END,
+};
+
/*
* Common ftr bits for a 32bit register with all hidden, strict
* attributes, with 4bit feature fields and a default safe value of
@@ -687,6 +693,7 @@ static const struct __ftr_reg_entry {
/* Op1 = 0, CRn = 1, CRm = 2 */
ARM64_FTR_REG(SYS_ZCR_EL1, ftr_zcr),
+ ARM64_FTR_REG(SYS_SMCR_EL1, ftr_smcr),
/* Op1 = 1, CRn = 0, CRm = 0 */
ARM64_FTR_REG(SYS_GMID_EL1, ftr_gmid),
@@ -991,6 +998,12 @@ void __init init_cpu_features(struct cpuinfo_arm64 *info)
vec_init_vq_map(ARM64_VEC_SVE);
}
+ if (id_aa64pfr1_sme(info->reg_id_aa64pfr1)) {
+ init_cpu_ftr_reg(SYS_SMCR_EL1, info->reg_smcr);
+ if (IS_ENABLED(CONFIG_ARM64_SME))
+ vec_init_vq_map(ARM64_VEC_SME);
+ }
+
if (id_aa64pfr1_mte(info->reg_id_aa64pfr1))
init_cpu_ftr_reg(SYS_GMID_EL1, info->reg_gmid);
@@ -1217,6 +1230,9 @@ void update_cpu_features(int cpu,
taint |= check_update_ftr_reg(SYS_ID_AA64ZFR0_EL1, cpu,
info->reg_id_aa64zfr0, boot->reg_id_aa64zfr0);
+ taint |= check_update_ftr_reg(SYS_ID_AA64SMFR0_EL1, cpu,
+ info->reg_id_aa64smfr0, boot->reg_id_aa64smfr0);
+
if (id_aa64pfr0_sve(info->reg_id_aa64pfr0)) {
taint |= check_update_ftr_reg(SYS_ZCR_EL1, cpu,
info->reg_zcr, boot->reg_zcr);
@@ -1227,6 +1243,16 @@ void update_cpu_features(int cpu,
vec_update_vq_map(ARM64_VEC_SVE);
}
+ if (id_aa64pfr1_sme(info->reg_id_aa64pfr1)) {
+ taint |= check_update_ftr_reg(SYS_SMCR_EL1, cpu,
+ info->reg_smcr, boot->reg_smcr);
+
+ /* Probe vector lengths, unless we already gave up on SME */
+ if (id_aa64pfr1_sme(read_sanitised_ftr_reg(SYS_ID_AA64PFR1_EL1)) &&
+ !system_capabilities_finalized())
+ vec_update_vq_map(ARM64_VEC_SME);
+ }
+
/*
* The kernel uses the LDGM/STGM instructions and the number of tags
* they read/write depends on the GMID_EL1.BS field. Check that the
@@ -2931,6 +2957,23 @@ static void verify_sve_features(void)
/* Add checks on other ZCR bits here if necessary */
}
+static void verify_sme_features(void)
+{
+ u64 safe_smcr = read_sanitised_ftr_reg(SYS_SMCR_EL1);
+ u64 smcr = read_smcr_features();
+
+ unsigned int safe_len = safe_smcr & SMCR_ELx_LEN_MASK;
+ unsigned int len = smcr & SMCR_ELx_LEN_MASK;
+
+ if (len < safe_len || vec_verify_vq_map(ARM64_VEC_SME)) {
+ pr_crit("CPU%d: SME: vector length support mismatch\n",
+ smp_processor_id());
+ cpu_die_early();
+ }
+
+ /* Add checks on other SMCR bits here if necessary */
+}
+
static void verify_hyp_capabilities(void)
{
u64 safe_mmfr1, mmfr0, mmfr1;
@@ -2983,6 +3026,9 @@ static void verify_local_cpu_capabilities(void)
if (system_supports_sve())
verify_sve_features();
+ if (system_supports_sme())
+ verify_sme_features();
+
if (is_hyp_mode_available())
verify_hyp_capabilities();
}
@@ -3100,6 +3146,7 @@ void __init setup_cpu_features(void)
pr_info("emulated: Privileged Access Never (PAN) using TTBR0_EL1 switching\n");
sve_setup();
+ sme_setup();
minsigstksz_setup();
/* Advertise that we have computed the system capabilities */