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-rw-r--r--arch/arm64/kernel/cpufeature.c120
-rw-r--r--arch/arm64/kernel/cpuinfo.c14
-rw-r--r--arch/arm64/kernel/elfcore.c2
-rw-r--r--arch/arm64/kernel/entry-common.c11
-rw-r--r--arch/arm64/kernel/entry-fpsimd.S36
-rw-r--r--arch/arm64/kernel/fpsimd.c585
-rw-r--r--arch/arm64/kernel/process.c44
-rw-r--r--arch/arm64/kernel/ptrace.c358
-rw-r--r--arch/arm64/kernel/signal.c188
-rw-r--r--arch/arm64/kernel/syscall.c29
-rw-r--r--arch/arm64/kernel/traps.c1
11 files changed, 1278 insertions, 110 deletions
diff --git a/arch/arm64/kernel/cpufeature.c b/arch/arm64/kernel/cpufeature.c
index d72c4b4d389c..78ed5fc762eb 100644
--- a/arch/arm64/kernel/cpufeature.c
+++ b/arch/arm64/kernel/cpufeature.c
@@ -237,6 +237,7 @@ static const struct arm64_ftr_bits ftr_id_aa64isar2[] = {
ARM64_FTR_BITS(FTR_VISIBLE_IF_IS_ENABLED(CONFIG_ARM64_PTR_AUTH),
FTR_STRICT, FTR_LOWER_SAFE, ID_AA64ISAR2_GPA3_SHIFT, 4, 0),
ARM64_FTR_BITS(FTR_VISIBLE, FTR_NONSTRICT, FTR_LOWER_SAFE, ID_AA64ISAR2_RPRES_SHIFT, 4, 0),
+ ARM64_FTR_BITS(FTR_VISIBLE, FTR_NONSTRICT, FTR_LOWER_SAFE, ID_AA64ISAR2_WFXT_SHIFT, 4, 0),
ARM64_FTR_END,
};
@@ -261,6 +262,8 @@ static const struct arm64_ftr_bits ftr_id_aa64pfr0[] = {
};
static const struct arm64_ftr_bits ftr_id_aa64pfr1[] = {
+ ARM64_FTR_BITS(FTR_VISIBLE_IF_IS_ENABLED(CONFIG_ARM64_SME),
+ FTR_STRICT, FTR_LOWER_SAFE, ID_AA64PFR1_SME_SHIFT, 4, 0),
ARM64_FTR_BITS(FTR_HIDDEN, FTR_STRICT, FTR_LOWER_SAFE, ID_AA64PFR1_MPAMFRAC_SHIFT, 4, 0),
ARM64_FTR_BITS(FTR_HIDDEN, FTR_STRICT, FTR_LOWER_SAFE, ID_AA64PFR1_RASFRAC_SHIFT, 4, 0),
ARM64_FTR_BITS(FTR_VISIBLE_IF_IS_ENABLED(CONFIG_ARM64_MTE),
@@ -293,6 +296,24 @@ static const struct arm64_ftr_bits ftr_id_aa64zfr0[] = {
ARM64_FTR_END,
};
+static const struct arm64_ftr_bits ftr_id_aa64smfr0[] = {
+ ARM64_FTR_BITS(FTR_VISIBLE_IF_IS_ENABLED(CONFIG_ARM64_SME),
+ FTR_STRICT, FTR_EXACT, ID_AA64SMFR0_FA64_SHIFT, 1, 0),
+ ARM64_FTR_BITS(FTR_VISIBLE_IF_IS_ENABLED(CONFIG_ARM64_SME),
+ FTR_STRICT, FTR_EXACT, ID_AA64SMFR0_I16I64_SHIFT, 4, 0),
+ ARM64_FTR_BITS(FTR_VISIBLE_IF_IS_ENABLED(CONFIG_ARM64_SME),
+ FTR_STRICT, FTR_EXACT, ID_AA64SMFR0_F64F64_SHIFT, 1, 0),
+ ARM64_FTR_BITS(FTR_VISIBLE_IF_IS_ENABLED(CONFIG_ARM64_SME),
+ FTR_STRICT, FTR_EXACT, ID_AA64SMFR0_I8I32_SHIFT, 4, 0),
+ ARM64_FTR_BITS(FTR_VISIBLE_IF_IS_ENABLED(CONFIG_ARM64_SME),
+ FTR_STRICT, FTR_EXACT, ID_AA64SMFR0_F16F32_SHIFT, 1, 0),
+ ARM64_FTR_BITS(FTR_VISIBLE_IF_IS_ENABLED(CONFIG_ARM64_SME),
+ FTR_STRICT, FTR_EXACT, ID_AA64SMFR0_B16F32_SHIFT, 1, 0),
+ ARM64_FTR_BITS(FTR_VISIBLE_IF_IS_ENABLED(CONFIG_ARM64_SME),
+ FTR_STRICT, FTR_EXACT, ID_AA64SMFR0_F32F32_SHIFT, 1, 0),
+ ARM64_FTR_END,
+};
+
static const struct arm64_ftr_bits ftr_id_aa64mmfr0[] = {
ARM64_FTR_BITS(FTR_VISIBLE, FTR_STRICT, FTR_LOWER_SAFE, ID_AA64MMFR0_ECV_SHIFT, 4, 0),
ARM64_FTR_BITS(FTR_HIDDEN, FTR_STRICT, FTR_LOWER_SAFE, ID_AA64MMFR0_FGT_SHIFT, 4, 0),
@@ -561,6 +582,12 @@ 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
@@ -645,6 +672,7 @@ static const struct __ftr_reg_entry {
ARM64_FTR_REG_OVERRIDE(SYS_ID_AA64PFR1_EL1, ftr_id_aa64pfr1,
&id_aa64pfr1_override),
ARM64_FTR_REG(SYS_ID_AA64ZFR0_EL1, ftr_id_aa64zfr0),
+ ARM64_FTR_REG(SYS_ID_AA64SMFR0_EL1, ftr_id_aa64smfr0),
/* Op1 = 0, CRn = 0, CRm = 5 */
ARM64_FTR_REG(SYS_ID_AA64DFR0_EL1, ftr_id_aa64dfr0),
@@ -666,6 +694,7 @@ 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),
@@ -960,6 +989,7 @@ void __init init_cpu_features(struct cpuinfo_arm64 *info)
init_cpu_ftr_reg(SYS_ID_AA64PFR0_EL1, info->reg_id_aa64pfr0);
init_cpu_ftr_reg(SYS_ID_AA64PFR1_EL1, info->reg_id_aa64pfr1);
init_cpu_ftr_reg(SYS_ID_AA64ZFR0_EL1, info->reg_id_aa64zfr0);
+ init_cpu_ftr_reg(SYS_ID_AA64SMFR0_EL1, info->reg_id_aa64smfr0);
if (id_aa64pfr0_32bit_el0(info->reg_id_aa64pfr0))
init_32bit_cpu_features(&info->aarch32);
@@ -969,6 +999,12 @@ 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);
@@ -1195,6 +1231,9 @@ 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);
@@ -1205,6 +1244,16 @@ 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
@@ -1288,6 +1337,7 @@ u64 __read_sysreg_by_encoding(u32 sys_id)
read_sysreg_case(SYS_ID_AA64PFR0_EL1);
read_sysreg_case(SYS_ID_AA64PFR1_EL1);
read_sysreg_case(SYS_ID_AA64ZFR0_EL1);
+ read_sysreg_case(SYS_ID_AA64SMFR0_EL1);
read_sysreg_case(SYS_ID_AA64DFR0_EL1);
read_sysreg_case(SYS_ID_AA64DFR1_EL1);
read_sysreg_case(SYS_ID_AA64MMFR0_EL1);
@@ -2442,6 +2492,44 @@ static const struct arm64_cpu_capabilities arm64_features[] = {
.matches = has_cpuid_feature,
.min_field_value = 1,
},
+#ifdef CONFIG_ARM64_SME
+ {
+ .desc = "Scalable Matrix Extension",
+ .type = ARM64_CPUCAP_SYSTEM_FEATURE,
+ .capability = ARM64_SME,
+ .sys_reg = SYS_ID_AA64PFR1_EL1,
+ .sign = FTR_UNSIGNED,
+ .field_pos = ID_AA64PFR1_SME_SHIFT,
+ .field_width = 4,
+ .min_field_value = ID_AA64PFR1_SME,
+ .matches = has_cpuid_feature,
+ .cpu_enable = sme_kernel_enable,
+ },
+ /* FA64 should be sorted after the base SME capability */
+ {
+ .desc = "FA64",
+ .type = ARM64_CPUCAP_SYSTEM_FEATURE,
+ .capability = ARM64_SME_FA64,
+ .sys_reg = SYS_ID_AA64SMFR0_EL1,
+ .sign = FTR_UNSIGNED,
+ .field_pos = ID_AA64SMFR0_FA64_SHIFT,
+ .field_width = 1,
+ .min_field_value = ID_AA64SMFR0_FA64,
+ .matches = has_cpuid_feature,
+ .cpu_enable = fa64_kernel_enable,
+ },
+#endif /* CONFIG_ARM64_SME */
+ {
+ .desc = "WFx with timeout",
+ .capability = ARM64_HAS_WFXT,
+ .type = ARM64_CPUCAP_SYSTEM_FEATURE,
+ .sys_reg = SYS_ID_AA64ISAR2_EL1,
+ .sign = FTR_UNSIGNED,
+ .field_pos = ID_AA64ISAR2_WFXT_SHIFT,
+ .field_width = 4,
+ .matches = has_cpuid_feature,
+ .min_field_value = ID_AA64ISAR2_WFXT_SUPPORTED,
+ },
{},
};
@@ -2575,6 +2663,17 @@ static const struct arm64_cpu_capabilities arm64_elf_hwcaps[] = {
HWCAP_CAP(SYS_ID_AA64MMFR0_EL1, ID_AA64MMFR0_ECV_SHIFT, 4, FTR_UNSIGNED, 1, CAP_HWCAP, KERNEL_HWCAP_ECV),
HWCAP_CAP(SYS_ID_AA64MMFR1_EL1, ID_AA64MMFR1_AFP_SHIFT, 4, FTR_UNSIGNED, 1, CAP_HWCAP, KERNEL_HWCAP_AFP),
HWCAP_CAP(SYS_ID_AA64ISAR2_EL1, ID_AA64ISAR2_RPRES_SHIFT, 4, FTR_UNSIGNED, 1, CAP_HWCAP, KERNEL_HWCAP_RPRES),
+ HWCAP_CAP(SYS_ID_AA64ISAR2_EL1, ID_AA64ISAR2_WFXT_SHIFT, 4, FTR_UNSIGNED, ID_AA64ISAR2_WFXT_SUPPORTED, CAP_HWCAP, KERNEL_HWCAP_WFXT),
+#ifdef CONFIG_ARM64_SME
+ HWCAP_CAP(SYS_ID_AA64PFR1_EL1, ID_AA64PFR1_SME_SHIFT, 4, FTR_UNSIGNED, ID_AA64PFR1_SME, CAP_HWCAP, KERNEL_HWCAP_SME),
+ HWCAP_CAP(SYS_ID_AA64SMFR0_EL1, ID_AA64SMFR0_FA64_SHIFT, 1, FTR_UNSIGNED, ID_AA64SMFR0_FA64, CAP_HWCAP, KERNEL_HWCAP_SME_FA64),
+ HWCAP_CAP(SYS_ID_AA64SMFR0_EL1, ID_AA64SMFR0_I16I64_SHIFT, 4, FTR_UNSIGNED, ID_AA64SMFR0_I16I64, CAP_HWCAP, KERNEL_HWCAP_SME_I16I64),
+ HWCAP_CAP(SYS_ID_AA64SMFR0_EL1, ID_AA64SMFR0_F64F64_SHIFT, 1, FTR_UNSIGNED, ID_AA64SMFR0_F64F64, CAP_HWCAP, KERNEL_HWCAP_SME_F64F64),
+ HWCAP_CAP(SYS_ID_AA64SMFR0_EL1, ID_AA64SMFR0_I8I32_SHIFT, 4, FTR_UNSIGNED, ID_AA64SMFR0_I8I32, CAP_HWCAP, KERNEL_HWCAP_SME_I8I32),
+ HWCAP_CAP(SYS_ID_AA64SMFR0_EL1, ID_AA64SMFR0_F16F32_SHIFT, 1, FTR_UNSIGNED, ID_AA64SMFR0_F16F32, CAP_HWCAP, KERNEL_HWCAP_SME_F16F32),
+ HWCAP_CAP(SYS_ID_AA64SMFR0_EL1, ID_AA64SMFR0_B16F32_SHIFT, 1, FTR_UNSIGNED, ID_AA64SMFR0_B16F32, CAP_HWCAP, KERNEL_HWCAP_SME_B16F32),
+ HWCAP_CAP(SYS_ID_AA64SMFR0_EL1, ID_AA64SMFR0_F32F32_SHIFT, 1, FTR_UNSIGNED, ID_AA64SMFR0_F32F32, CAP_HWCAP, KERNEL_HWCAP_SME_F32F32),
+#endif /* CONFIG_ARM64_SME */
{},
};
@@ -2872,6 +2971,23 @@ 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;
@@ -2924,6 +3040,9 @@ 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();
}
@@ -3041,6 +3160,7 @@ 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 */
diff --git a/arch/arm64/kernel/cpuinfo.c b/arch/arm64/kernel/cpuinfo.c
index 330b92ea863a..8eff0a34ffd4 100644
--- a/arch/arm64/kernel/cpuinfo.c
+++ b/arch/arm64/kernel/cpuinfo.c
@@ -98,6 +98,15 @@ static const char *const hwcap_str[] = {
[KERNEL_HWCAP_AFP] = "afp",
[KERNEL_HWCAP_RPRES] = "rpres",
[KERNEL_HWCAP_MTE3] = "mte3",
+ [KERNEL_HWCAP_SME] = "sme",
+ [KERNEL_HWCAP_SME_I16I64] = "smei16i64",
+ [KERNEL_HWCAP_SME_F64F64] = "smef64f64",
+ [KERNEL_HWCAP_SME_I8I32] = "smei8i32",
+ [KERNEL_HWCAP_SME_F16F32] = "smef16f32",
+ [KERNEL_HWCAP_SME_B16F32] = "smeb16f32",
+ [KERNEL_HWCAP_SME_F32F32] = "smef32f32",
+ [KERNEL_HWCAP_SME_FA64] = "smefa64",
+ [KERNEL_HWCAP_WFXT] = "wfxt",
};
#ifdef CONFIG_COMPAT
@@ -401,6 +410,7 @@ static void __cpuinfo_store_cpu(struct cpuinfo_arm64 *info)
info->reg_id_aa64pfr0 = read_cpuid(ID_AA64PFR0_EL1);
info->reg_id_aa64pfr1 = read_cpuid(ID_AA64PFR1_EL1);
info->reg_id_aa64zfr0 = read_cpuid(ID_AA64ZFR0_EL1);
+ info->reg_id_aa64smfr0 = read_cpuid(ID_AA64SMFR0_EL1);
if (id_aa64pfr1_mte(info->reg_id_aa64pfr1))
info->reg_gmid = read_cpuid(GMID_EL1);
@@ -412,6 +422,10 @@ static void __cpuinfo_store_cpu(struct cpuinfo_arm64 *info)
id_aa64pfr0_sve(info->reg_id_aa64pfr0))
info->reg_zcr = read_zcr_features();
+ if (IS_ENABLED(CONFIG_ARM64_SME) &&
+ id_aa64pfr1_sme(info->reg_id_aa64pfr1))
+ info->reg_smcr = read_smcr_features();
+
cpuinfo_detect_icache_policy(info);
}
diff --git a/arch/arm64/kernel/elfcore.c b/arch/arm64/kernel/elfcore.c
index 2b3f3d0544b9..98d67444a5b6 100644
--- a/arch/arm64/kernel/elfcore.c
+++ b/arch/arm64/kernel/elfcore.c
@@ -95,7 +95,7 @@ int elf_core_write_extra_phdrs(struct coredump_params *cprm, loff_t offset)
for_each_mte_vma(current, vma) {
struct elf_phdr phdr;
- phdr.p_type = PT_ARM_MEMTAG_MTE;
+ phdr.p_type = PT_AARCH64_MEMTAG_MTE;
phdr.p_offset = offset;
phdr.p_vaddr = vma->vm_start;
phdr.p_paddr = 0;
diff --git a/arch/arm64/kernel/entry-common.c b/arch/arm64/kernel/entry-common.c
index 878c65aa7206..29139e9a1517 100644
--- a/arch/arm64/kernel/entry-common.c
+++ b/arch/arm64/kernel/entry-common.c
@@ -537,6 +537,14 @@ static void noinstr el0_sve_acc(struct pt_regs *regs, unsigned long esr)
exit_to_user_mode(regs);
}
+static void noinstr el0_sme_acc(struct pt_regs *regs, unsigned long esr)
+{
+ enter_from_user_mode(regs);
+ local_daif_restore(DAIF_PROCCTX);
+ do_sme_acc(esr, regs);
+ exit_to_user_mode(regs);
+}
+
static void noinstr el0_fpsimd_exc(struct pt_regs *regs, unsigned long esr)
{
enter_from_user_mode(regs);
@@ -645,6 +653,9 @@ asmlinkage void noinstr el0t_64_sync_handler(struct pt_regs *regs)
case ESR_ELx_EC_SVE:
el0_sve_acc(regs, esr);
break;
+ case ESR_ELx_EC_SME:
+ el0_sme_acc(regs, esr);
+ break;
case ESR_ELx_EC_FP_EXC64:
el0_fpsimd_exc(regs, esr);
break;
diff --git a/arch/arm64/kernel/entry-fpsimd.S b/arch/arm64/kernel/entry-fpsimd.S
index dc242e269f9a..229436f33df5 100644
--- a/arch/arm64/kernel/entry-fpsimd.S
+++ b/arch/arm64/kernel/entry-fpsimd.S
@@ -86,3 +86,39 @@ SYM_FUNC_START(sve_flush_live)
SYM_FUNC_END(sve_flush_live)
#endif /* CONFIG_ARM64_SVE */
+
+#ifdef CONFIG_ARM64_SME
+
+SYM_FUNC_START(sme_get_vl)
+ _sme_rdsvl 0, 1
+ ret
+SYM_FUNC_END(sme_get_vl)
+
+SYM_FUNC_START(sme_set_vq)
+ sme_load_vq x0, x1, x2
+ ret
+SYM_FUNC_END(sme_set_vq)
+
+/*
+ * Save the SME state
+ *
+ * x0 - pointer to buffer for state
+ */
+SYM_FUNC_START(za_save_state)
+ _sme_rdsvl 1, 1 // x1 = VL/8
+ sme_save_za 0, x1, 12
+ ret
+SYM_FUNC_END(za_save_state)
+
+/*
+ * Load the SME state
+ *
+ * x0 - pointer to buffer for state
+ */
+SYM_FUNC_START(za_load_state)
+ _sme_rdsvl 1, 1 // x1 = VL/8
+ sme_load_za 0, x1, 12
+ ret
+SYM_FUNC_END(za_load_state)
+
+#endif /* CONFIG_ARM64_SME */
diff --git a/arch/arm64/kernel/fpsimd.c b/arch/arm64/kernel/fpsimd.c
index 47af76e53221..64431bc62472 100644
--- a/arch/arm64/kernel/fpsimd.c
+++ b/arch/arm64/kernel/fpsimd.c
@@ -121,7 +121,10 @@
struct fpsimd_last_state_struct {
struct user_fpsimd_state *st;
void *sve_state;
+ void *za_state;
+ u64 *svcr;
unsigned int sve_vl;
+ unsigned int sme_vl;
};
static DEFINE_PER_CPU(struct fpsimd_last_state_struct, fpsimd_last_state);
@@ -136,6 +139,12 @@ __ro_after_init struct vl_info vl_info[ARM64_VEC_MAX] = {
.max_virtualisable_vl = SVE_VL_MIN,
},
#endif
+#ifdef CONFIG_ARM64_SME
+ [ARM64_VEC_SME] = {
+ .type = ARM64_VEC_SME,
+ .name = "SME",
+ },
+#endif
};
static unsigned int vec_vl_inherit_flag(enum vec_type type)
@@ -143,6 +152,8 @@ static unsigned int vec_vl_inherit_flag(enum vec_type type)
switch (type) {
case ARM64_VEC_SVE:
return TIF_SVE_VL_INHERIT;
+ case ARM64_VEC_SME:
+ return TIF_SME_VL_INHERIT;
default:
WARN_ON_ONCE(1);
return 0;
@@ -186,6 +197,26 @@ extern void __percpu *efi_sve_state;
#endif /* ! CONFIG_ARM64_SVE */
+#ifdef CONFIG_ARM64_SME
+
+static int get_sme_default_vl(void)
+{
+ return get_default_vl(ARM64_VEC_SME);
+}
+
+static void set_sme_default_vl(int val)
+{
+ set_default_vl(ARM64_VEC_SME, val);
+}
+
+static void sme_free(struct task_struct *);
+
+#else
+
+static inline void sme_free(struct task_struct *t) { }
+
+#endif
+
DEFINE_PER_CPU(bool, fpsimd_context_busy);
EXPORT_PER_CPU_SYMBOL(fpsimd_context_busy);
@@ -279,16 +310,27 @@ void task_set_vl_onexec(struct task_struct *task, enum vec_type type,
}
/*
+ * TIF_SME controls whether a task can use SME without trapping while
+ * in userspace, when TIF_SME is set then we must have storage
+ * alocated in sve_state and za_state to store the contents of both ZA
+ * and the SVE registers for both streaming and non-streaming modes.
+ *
+ * If both SVCR.ZA and SVCR.SM are disabled then at any point we
+ * may disable TIF_SME and reenable traps.
+ */
+
+
+/*
* TIF_SVE controls whether a task can use SVE without trapping while
- * in userspace, and also the way a task's FPSIMD/SVE state is stored
- * in thread_struct.
+ * in userspace, and also (together with TIF_SME) the way a task's
+ * FPSIMD/SVE state is stored in thread_struct.
*
* The kernel uses this flag to track whether a user task is actively
* using SVE, and therefore whether full SVE register state needs to
* be tracked. If not, the cheaper FPSIMD context handling code can
* be used instead of the more costly SVE equivalents.
*
- * * TIF_SVE set:
+ * * TIF_SVE or SVCR.SM set:
*
* The task can execute SVE instructions while in userspace without
* trapping to the kernel.
@@ -296,7 +338,8 @@ void task_set_vl_onexec(struct task_struct *task, enum vec_type type,
* When stored, Z0-Z31 (incorporating Vn in bits[127:0] or the
* corresponding Zn), P0-P15 and FFR are encoded in in
* task->thread.sve_state, formatted appropriately for vector
- * length task->thread.sve_vl.
+ * length task->thread.sve_vl or, if SVCR.SM is set,
+ * task->thread.sme_vl.
*
* task->thread.sve_state must point to a valid buffer at least
* sve_state_size(task) bytes in size.
@@ -334,16 +377,44 @@ void task_set_vl_onexec(struct task_struct *task, enum vec_type type,
*/
static void task_fpsimd_load(void)
{
+ bool restore_sve_regs = false;
+ bool restore_ffr;
+
WARN_ON(!system_supports_fpsimd());
WARN_ON(!have_cpu_fpsimd_context());
+ /* Check if we should restore SVE first */
if (IS_ENABLED(CONFIG_ARM64_SVE) && test_thread_flag(TIF_SVE)) {
sve_set_vq(sve_vq_from_vl(task_get_sve_vl(current)) - 1);
+ restore_sve_regs = true;
+ restore_ffr = true;
+ }
+
+ /* Restore SME, override SVE register configuration if needed */
+ if (system_supports_sme()) {
+ unsigned long sme_vl = task_get_sme_vl(current);
+
+ /* Ensure VL is set up for restoring data */
+ if (test_thread_flag(TIF_SME))
+ sme_set_vq(sve_vq_from_vl(sme_vl) - 1);
+
+ write_sysreg_s(current->thread.svcr, SYS_SVCR_EL0);
+
+ if (thread_za_enabled(&current->thread))
+ za_load_state(current->thread.za_state);
+
+ if (thread_sm_enabled(&current->thread)) {
+ restore_sve_regs = true;
+ restore_ffr = system_supports_fa64();
+ }
+ }
+
+ if (restore_sve_regs)
sve_load_state(sve_pffr(&current->thread),
- &current->thread.uw.fpsimd_state.fpsr, true);
- } else {
+ &current->thread.uw.fpsimd_state.fpsr,
+ restore_ffr);
+ else
fpsimd_load_state(&current->thread.uw.fpsimd_state);
- }
}
/*
@@ -361,6 +432,9 @@ static void fpsimd_save(void)
struct fpsimd_last_state_struct const *last =
this_cpu_ptr(&fpsimd_last_state);
/* set by fpsimd_bind_task_to_cpu() or fpsimd_bind_state_to_cpu() */
+ bool save_sve_regs = false;
+ bool save_ffr;
+ unsigned int vl;
WARN_ON(!system_supports_fpsimd());
WARN_ON(!have_cpu_fpsimd_context());
@@ -368,9 +442,32 @@ static void fpsimd_save(void)
if (test_thread_flag(TIF_FOREIGN_FPSTATE))
return;
- if (IS_ENABLED(CONFIG_ARM64_SVE) &&
- test_thread_flag(TIF_SVE)) {
- if (WARN_ON(sve_get_vl() != last->sve_vl)) {
+ if (test_thread_flag(TIF_SVE)) {
+ save_sve_regs = true;
+ save_ffr = true;
+ vl = last->sve_vl;
+ }
+
+ if (system_supports_sme()) {
+ u64 *svcr = last->svcr;
+ *svcr = read_sysreg_s(SYS_SVCR_EL0);
+
+ *svcr = read_sysreg_s(SYS_SVCR_EL0);
+
+ if (*svcr & SYS_SVCR_EL0_ZA_MASK)
+ za_save_state(last->za_state);
+
+ /* If we are in streaming mode override regular SVE. */
+ if (*svcr & SYS_SVCR_EL0_SM_MASK) {
+ save_sve_regs = true;
+ save_ffr = system_supports_fa64();
+ vl = last->sme_vl;
+ }
+ }
+
+ if (IS_ENABLED(CONFIG_ARM64_SVE) && save_sve_regs) {
+ /* Get the configured VL from RDVL, will account for SM */
+ if (WARN_ON(sve_get_vl() != vl)) {
/*
* Can't save the user regs, so current would
* re-enter user with corrupt state.
@@ -381,8 +478,8 @@ static void fpsimd_save(void)
}
sve_save_state((char *)last->sve_state +
- sve_ffr_offset(last->sve_vl),
- &last->st->fpsr, true);
+ sve_ffr_offset(vl),
+ &last->st->fpsr, save_ffr);
} else {
fpsimd_save_state(last->st);
}
@@ -409,6 +506,8 @@ static unsigned int find_supported_vector_length(enum vec_type type,
if (vl > max_vl)
vl = max_vl;
+ if (vl < info->min_vl)
+ vl = info->min_vl;
bit = find_next_bit(info->vq_map, SVE_VQ_MAX,
__vq_to_bit(sve_vq_from_vl(vl)));
@@ -467,6 +566,30 @@ static int __init sve_sysctl_init(void)
static int __init sve_sysctl_init(void) { return 0; }
#endif /* ! (CONFIG_ARM64_SVE && CONFIG_SYSCTL) */
+#if defined(CONFIG_ARM64_SME) && defined(CONFIG_SYSCTL)
+static struct ctl_table sme_default_vl_table[] = {
+ {
+ .procname = "sme_default_vector_length",
+ .mode = 0644,
+ .proc_handler = vec_proc_do_default_vl,
+ .extra1 = &vl_info[ARM64_VEC_SME],
+ },
+ { }
+};
+
+static int __init sme_sysctl_init(void)
+{
+ if (system_supports_sme())
+ if (!register_sysctl("abi", sme_default_vl_table))
+ return -EINVAL;
+
+ return 0;
+}
+
+#else /* ! (CONFIG_ARM64_SME && CONFIG_SYSCTL) */
+static int __init sme_sysctl_init(void) { return 0; }
+#endif /* ! (CONFIG_ARM64_SME && CONFIG_SYSCTL) */
+
#define ZREG(sve_state, vq, n) ((char *)(sve_state) + \
(SVE_SIG_ZREG_OFFSET(vq, n) - SVE_SIG_REGS_OFFSET))
@@ -520,7 +643,7 @@ static void fpsimd_to_sve(struct task_struct *task)
if (!system_supports_sve())
return;
- vq = sve_vq_from_vl(task_get_sve_vl(task));
+ vq = sve_vq_from_vl(thread_get_cur_vl(&task->thread));
__fpsimd_to_sve(sst, fst, vq);
}
@@ -537,7 +660,7 @@ static void fpsimd_to_sve(struct task_struct *task)
*/
static void sve_to_fpsimd(struct task_struct *task)
{
- unsigned int vq;
+ unsigned int vq, vl;
void const *sst = task->thread.sve_state;
struct user_fpsimd_state *fst = &task->thread.uw.fpsimd_state;
unsigned int i;
@@ -546,7 +669,8 @@ static void sve_to_fpsimd(struct task_struct *task)
if (!system_supports_sve())
return;
- vq = sve_vq_from_vl(task_get_sve_vl(task));
+ vl = thread_get_cur_vl(&task->thread);
+ vq = sve_vq_from_vl(vl);
for (i = 0; i < SVE_NUM_ZREGS; ++i) {
p = (__uint128_t const *)ZREG(sst, vq, i);
fst->vregs[i] = arm64_le128_to_cpu(*p);
@@ -559,9 +683,16 @@ static void sve_to_fpsimd(struct task_struct *task)
* Return how many bytes of memory are required to store the full SVE
* state for task, given task's currently configured vector length.
*/
-static size_t sve_state_size(struct task_struct const *task)
+size_t sve_state_size(struct task_struct const *task)
{
- return SVE_SIG_REGS_SIZE(sve_vq_from_vl(task_get_sve_vl(task)));
+ unsigned int vl = 0;
+
+ if (system_supports_sve())
+ vl = task_get_sve_vl(task);
+ if (system_supports_sme())
+ vl = max(vl, task_get_sme_vl(task));
+
+ return SVE_SIG_REGS_SIZE(sve_vq_from_vl(vl));
}
/*
@@ -588,6 +719,19 @@ void sve_alloc(struct task_struct *task)
/*
+ * Force the FPSIMD state shared with SVE to be updated in the SVE state
+ * even if the SVE state is the current active state.
+ *
+ * This should only be called by ptrace. task must be non-runnable.
+ * task->thread.sve_state must point to at least sve_state_size(task)
+ * bytes of allocated kernel memory.
+ */
+void fpsimd_force_sync_to_sve(struct task_struct *task)
+{
+ fpsimd_to_sve(task);
+}
+
+/*
* Ensure that task->thread.sve_state is up to date with respect to
* the user task, irrespective of when SVE is in use or not.
*
@@ -597,7 +741,8 @@ void sve_alloc(struct task_struct *task)
*/
void fpsimd_sync_to_sve(struct task_struct *task)
{
- if (!test_tsk_thread_flag(task, TIF_SVE))
+ if (!test_tsk_thread_flag(task, TIF_SVE) &&
+ !thread_sm_enabled(&task->thread))
fpsimd_to_sve(task);
}
@@ -611,7 +756,8 @@ void fpsimd_sync_to_sve(struct task_struct *task)
*/
void sve_sync_to_fpsimd(struct task_struct *task)
{
- if (test_tsk_thread_flag(task, TIF_SVE))
+ if (test_tsk_thread_flag(task, TIF_SVE) ||
+ thread_sm_enabled(&task->thread))
sve_to_fpsimd(task);
}
@@ -636,7 +782,7 @@ void sve_sync_from_fpsimd_zeropad(struct task_struct *task)
if (!test_tsk_thread_flag(task, TIF_SVE))
return;
- vq = sve_vq_from_vl(task_get_sve_vl(task));
+ vq = sve_vq_from_vl(thread_get_cur_vl(&task->thread));
memset(sst, 0, SVE_SIG_REGS_SIZE(vq));
__fpsimd_to_sve(sst, fst, vq);
@@ -680,8 +826,7 @@ int vec_set_vector_length(struct task_struct *task, enum vec_type type,
/*
* To ensure the FPSIMD bits of the SVE vector registers are preserved,
* write any live register state back to task_struct, and convert to a
- * regular FPSIMD thread. Since the vector length can only be changed
- * with a syscall we can't be in streaming mode while reconfiguring.
+ * regular FPSIMD thread.
*/
if (task == current) {
get_cpu_fpsimd_context();
@@ -690,17 +835,26 @@ int vec_set_vector_length(struct task_struct *task, enum vec_type type,
}
fpsimd_flush_task_state(task);
- if (test_and_clear_tsk_thread_flag(task, TIF_SVE))
+ if (test_and_clear_tsk_thread_flag(task, TIF_SVE) ||
+ thread_sm_enabled(&task->thread))
sve_to_fpsimd(task);
+ if (system_supports_sme() && type == ARM64_VEC_SME) {
+ task->thread.svcr &= ~(SYS_SVCR_EL0_SM_MASK |
+ SYS_SVCR_EL0_ZA_MASK);
+ clear_thread_flag(TIF_SME);
+ }
+
if (task == current)
put_cpu_fpsimd_context();
/*
- * Force reallocation of task SVE state to the correct size
- * on next use:
+ * Force reallocation of task SVE and SME state to the correct
+ * size on next use:
*/
sve_free(task);
+ if (system_supports_sme() && type == ARM64_VEC_SME)
+ sme_free(task);
task_set_vl(task, type, vl);
@@ -761,6 +915,36 @@ int sve_get_current_vl(void)
return vec_prctl_status(ARM64_VEC_SVE, 0);
}
+#ifdef CONFIG_ARM64_SME
+/* PR_SME_SET_VL */
+int sme_set_current_vl(unsigned long arg)
+{
+ unsigned long vl, flags;
+ int ret;
+
+ vl = arg & PR_SME_VL_LEN_MASK;
+ flags = arg & ~vl;
+
+ if (!system_supports_sme() || is_compat_task())
+ return -EINVAL;
+
+ ret = vec_set_vector_length(current, ARM64_VEC_SME, vl, flags);
+ if (ret)
+ return ret;
+
+ return vec_prctl_status(ARM64_VEC_SME, flags);
+}
+
+/* PR_SME_GET_VL */
+int sme_get_current_vl(void)
+{
+ if (!system_supports_sme() || is_compat_task())
+ return -EINVAL;
+
+ return vec_prctl_status(ARM64_VEC_SME, 0);
+}
+#endif /* CONFIG_ARM64_SME */
+
static void vec_probe_vqs(struct vl_info *info,
DECLARE_BITMAP(map, SVE_VQ_MAX))
{
@@ -770,7 +954,23 @@ static void vec_probe_vqs(struct vl_info *info,
for (vq = SVE_VQ_MAX; vq >= SVE_VQ_MIN; --vq) {
write_vl(info->type, vq - 1); /* self-syncing */
- vl = sve_get_vl();
+
+ switch (info->type) {
+ case ARM64_VEC_SVE:
+ vl = sve_get_vl();
+ break;
+ case ARM64_VEC_SME:
+ vl = sme_get_vl();
+ break;
+ default:
+ vl = 0;
+ break;
+ }
+
+ /* Minimum VL identified? */
+ if (sve_vq_from_vl(vl) > vq)
+ break;
+
vq = sve_vq_from_vl(vl); /* skip intervening lengths */
set_bit(__vq_to_bit(vq), map);
}
@@ -856,21 +1056,25 @@ int vec_verify_vq_map(enum vec_type type)
static void __init sve_efi_setup(void)
{
- struct vl_info *info = &vl_info[ARM64_VEC_SVE];
+ int max_vl = 0;
+ int i;
if (!IS_ENABLED(CONFIG_EFI))
return;
+ for (i = 0; i < ARRAY_SIZE(vl_info); i++)
+ max_vl = max(vl_info[i].max_vl, max_vl);
+
/*
* alloc_percpu() warns and prints a backtrace if this goes wrong.
* This is evidence of a crippled system and we are returning void,
* so no attempt is made to handle this situation here.
*/
- if (!sve_vl_valid(info->max_vl))
+ if (!sve_vl_valid(max_vl))
goto fail;
efi_sve_state = __alloc_percpu(
- SVE_SIG_REGS_SIZE(sve_vq_from_vl(info->max_vl)), SVE_VQ_BYTES);
+ SVE_SIG_REGS_SIZE(sve_vq_from_vl(max_vl)), SVE_VQ_BYTES);
if (!efi_sve_state)
goto fail;
@@ -989,10 +1193,172 @@ void __init sve_setup(void)
void fpsimd_release_task(struct task_struct *dead_task)
{
__sve_free(dead_task);
+ sme_free(dead_task);
}
#endif /* CONFIG_ARM64_SVE */
+#ifdef CONFIG_ARM64_SME
+
+/*
+ * Ensure that task->thread.za_state is allocated and sufficiently large.
+ *
+ * This function should be used only in preparation for replacing
+ * task->thread.za_state with new data. The memory is always zeroed
+ * here to prevent stale data from showing through: this is done in
+ * the interest of testability and predictability, the architecture
+ * guarantees that when ZA is enabled it will be zeroed.
+ */
+void sme_alloc(struct task_struct *task)
+{
+ if (task->thread.za_state) {
+ memset(task->thread.za_state, 0, za_state_size(task));
+ return;
+ }
+
+ /* This could potentially be up to 64K. */
+ task->thread.za_state =
+ kzalloc(za_state_size(task), GFP_KERNEL);
+}
+
+static void sme_free(struct task_struct *task)
+{
+ kfree(task->thread.za_state);
+ task->thread.za_state = NULL;
+}
+
+void sme_kernel_enable(const struct arm64_cpu_capabilities *__always_unused p)
+{
+ /* Set priority for all PEs to architecturally defined minimum */
+ write_sysreg_s(read_sysreg_s(SYS_SMPRI_EL1) & ~SMPRI_EL1_PRIORITY_MASK,
+ SYS_SMPRI_EL1);
+
+ /* Allow SME in kernel */
+ write_sysreg(read_sysreg(CPACR_EL1) | CPACR_EL1_SMEN_EL1EN, CPACR_EL1);
+ isb();
+
+ /* Allow EL0 to access TPIDR2 */
+ write_sysreg(read_sysreg(SCTLR_EL1) | SCTLR_ELx_ENTP2, SCTLR_EL1);
+ isb();
+}
+
+/*
+ * This must be called after sme_kernel_enable(), we rely on the
+ * feature table being sorted to ensure this.
+ */
+void fa64_kernel_enable(const struct arm64_cpu_capabilities *__always_unused p)
+{
+ /* Allow use of FA64 */
+ write_sysreg_s(read_sysreg_s(SYS_SMCR_EL1) | SMCR_ELx_FA64_MASK,
+ SYS_SMCR_EL1);
+}
+
+/*
+ * Read the pseudo-SMCR used by cpufeatures to identify the supported
+ * vector length.
+ *
+ * Use only if SME is present.
+ * This function clobbers the SME vector length.
+ */
+u64 read_smcr_features(void)
+{
+ u64 smcr;
+ unsigned int vq_max;
+
+ sme_kernel_enable(NULL);
+ sme_smstart_sm();
+
+ /*
+ * Set the maximum possible VL.
+ */
+ write_sysreg_s(read_sysreg_s(SYS_SMCR_EL1) | SMCR_ELx_LEN_MASK,
+ SYS_SMCR_EL1);
+
+ smcr = read_sysreg_s(SYS_SMCR_EL1);
+ smcr &= ~(u64)SMCR_ELx_LEN_MASK; /* Only the LEN field */
+ vq_max = sve_vq_from_vl(sve_get_vl());
+ smcr |= vq_max - 1; /* set LEN field to maximum effective value */
+
+ sme_smstop_sm();
+
+ return smcr;
+}
+
+void __init sme_setup(void)
+{
+ struct vl_info *info = &vl_info[ARM64_VEC_SME];
+ u64 smcr;
+ int min_bit;
+
+ if (!system_supports_sme())
+ return;
+
+ /*
+ * SME doesn't require any particular vector length be
+ * supported but it does require at least one. We should have
+ * disabled the feature entirely while bringing up CPUs but
+ * let's double check here.
+ */
+ WARN_ON(bitmap_empty(info->vq_map, SVE_VQ_MAX));
+
+ min_bit = find_last_bit(info->vq_map, SVE_VQ_MAX);
+ info->min_vl = sve_vl_from_vq(__bit_to_vq(min_bit));
+
+ smcr = read_sanitised_ftr_reg(SYS_SMCR_EL1);
+ info->max_vl = sve_vl_from_vq((smcr & SMCR_ELx_LEN_MASK) + 1);
+
+ /*
+ * Sanity-check that the max VL we determined through CPU features
+ * corresponds properly to sme_vq_map. If not, do our best:
+ */
+ if (WARN_ON(info->max_vl != find_supported_vector_length(ARM64_VEC_SME,
+ info->max_vl)))
+ info->max_vl = find_supported_vector_length(ARM64_VEC_SME,
+ info->max_vl);
+
+ WARN_ON(info->min_vl > info->max_vl);
+
+ /*
+ * For the default VL, pick the maximum supported value <= 32
+ * (256 bits) if there is one since this is guaranteed not to
+ * grow the signal frame when in streaming mode, otherwise the
+ * minimum available VL will be used.
+ */
+ set_sme_default_vl(find_supported_vector_length(ARM64_VEC_SME, 32));
+
+ pr_info("SME: minimum available vector length %u bytes per vector\n",
+ info->min_vl);
+ pr_info("SME: maximum available vector length %u bytes per vector\n",
+ info->max_vl);
+ pr_info("SME: default vector length %u bytes per vector\n",
+ get_sme_default_vl());
+}
+
+#endif /* CONFIG_ARM64_SME */
+
+static void sve_init_regs(void)
+{
+ /*
+ * Convert the FPSIMD state to SVE, zeroing all the state that
+ * is not shared with FPSIMD. If (as is likely) the current
+ * state is live in the registers then do this there and
+ * update our metadata for the current task including
+ * disabling the trap, otherwise update our in-memory copy.
+ * We are guaranteed to not be in streaming mode, we can only
+ * take a SVE trap when not in streaming mode and we can't be
+ * in streaming mode when taking a SME trap.
+ */
+ if (!test_thread_flag(TIF_FOREIGN_FPSTATE)) {
+ unsigned long vq_minus_one =
+ sve_vq_from_vl(task_get_sve_vl(current)) - 1;
+ sve_set_vq(vq_minus_one);
+ sve_flush_live(true, vq_minus_one);
+ fpsimd_bind_task_to_cpu();
+ } else {
+ fpsimd_to_sve(current);
+ }
+}
+
/*
* Trapped SVE access
*
@@ -1024,22 +1390,77 @@ void do_sve_acc(unsigned int esr, struct pt_regs *regs)
WARN_ON(1); /* SVE access shouldn't have trapped */
/*
- * Convert the FPSIMD state to SVE, zeroing all the state that
- * is not shared with FPSIMD. If (as is likely) the current
- * state is live in the registers then do this there and
- * update our metadata for the current task including
- * disabling the trap, otherwise update our in-memory copy.
+ * Even if the task can have used streaming mode we can only
+ * generate SVE access traps in normal SVE mode and
+ * transitioning out of streaming mode may discard any
+ * streaming mode state. Always clear the high bits to avoid
+ * any potential errors tracking what is properly initialised.
*/
+ sve_init_regs();
+
+ put_cpu_fpsimd_context();
+}
+
+/*
+ * Trapped SME access
+ *
+ * Storage is allocated for the full SVE and SME state, the current
+ * FPSIMD register contents are migrated to SVE if SVE is not already
+ * active, and the access trap is disabled.
+ *
+ * TIF_SME should be clear on entry: otherwise, fpsimd_restore_current_state()
+ * would have disabled the SME access trap for userspace during
+ * ret_to_user, making an SVE access trap impossible in that case.
+ */
+void do_sme_acc(unsigned int esr, struct pt_regs *regs)
+{
+ /* Even if we chose not to use SME, the hardware could still trap: */
+ if (unlikely(!system_supports_sme()) || WARN_ON(is_compat_task())) {
+ force_signal_inject(SIGILL, ILL_ILLOPC, regs->pc, 0);
+ return;
+ }
+
+ /*
+ * If this not a trap due to SME being disabled then something
+ * is being used in the wrong mode, report as SIGILL.
+ */
+ if (ESR_ELx_ISS(esr) != ESR_ELx_SME_ISS_SME_DISABLED) {
+ force_signal_inject(SIGILL, ILL_ILLOPC, regs->pc, 0);
+ return;
+ }
+
+ sve_alloc(current);
+ sme_alloc(current);
+ if (!current->thread.sve_state || !current->thread.za_state) {
+ force_sig(SIGKILL);
+ return;
+ }
+
+ get_cpu_fpsimd_context();
+
+ /* With TIF_SME userspace shouldn't generate any traps */
+ if (test_and_set_thread_flag(TIF_SME))
+ WARN_ON(1);
+
if (!test_thread_flag(TIF_FOREIGN_FPSTATE)) {
unsigned long vq_minus_one =
- sve_vq_from_vl(task_get_sve_vl(current)) - 1;
- sve_set_vq(vq_minus_one);
- sve_flush_live(true, vq_minus_one);
+ sve_vq_from_vl(task_get_sme_vl(current)) - 1;
+ sme_set_vq(vq_minus_one);
+
fpsimd_bind_task_to_cpu();
- } else {
- fpsimd_to_sve(current);
}
+ /*
+ * If SVE was not already active initialise the SVE registers,
+ * any non-shared state between the streaming and regular SVE
+ * registers is architecturally guaranteed to be zeroed when
+ * we enter streaming mode. We do not need to initialize ZA
+ * since ZA must be disabled at this point and enabling ZA is
+ * architecturally defined to zero ZA.
+ */
+ if (system_supports_sve() && !test_thread_flag(TIF_SVE))
+ sve_init_regs();
+
put_cpu_fpsimd_context();
}
@@ -1156,6 +1577,13 @@ void fpsimd_flush_thread(void)
fpsimd_flush_thread_vl(ARM64_VEC_SVE);
}
+ if (system_supports_sme()) {
+ clear_thread_flag(TIF_SME);
+ sme_free(current);
+ fpsimd_flush_thread_vl(ARM64_VEC_SME);
+ current->thread.svcr = 0;
+ }
+
put_cpu_fpsimd_context();
}
@@ -1198,22 +1626,34 @@ static void fpsimd_bind_task_to_cpu(void)
WARN_ON(!system_supports_fpsimd());
last->st = &current->thread.uw.fpsimd_state;
last->sve_state = current->thread.sve_state;
+ last->za_state = current->thread.za_state;
last->sve_vl = task_get_sve_vl(current);
+ last->sme_vl = task_get_sme_vl(current);
+ last->svcr = &current->thread.svcr;
current->thread.fpsimd_cpu = smp_processor_id();
+ /*
+ * Toggle SVE and SME trapping for userspace if needed, these
+ * are serialsied by ret_to_user().
+ */
+ if (system_supports_sme()) {
+ if (test_thread_flag(TIF_SME))
+ sme_user_enable();
+ else
+ sme_user_disable();
+ }
+
if (system_supports_sve()) {
- /* Toggle SVE trapping for userspace if needed */
if (test_thread_flag(TIF_SVE))
sve_user_enable();
else
sve_user_disable();
-
- /* Serialised by exception return to user */
}
}
void fpsimd_bind_state_to_cpu(struct user_fpsimd_state *st, void *sve_state,
- unsigned int sve_vl)
+ unsigned int sve_vl, void *za_state,
+ unsigned int sme_vl, u64 *svcr)
{
struct fpsimd_last_state_struct *last =
this_cpu_ptr(&fpsimd_last_state);
@@ -1222,8 +1662,11 @@ void fpsimd_bind_state_to_cpu(struct user_fpsimd_state *st, void *sve_state,
WARN_ON(!in_softirq() && !irqs_disabled());
last->st = st;
+ last->svcr = svcr;
last->sve_state = sve_state;
+ last->za_state = za_state;
last->sve_vl = sve_vl;
+ last->sme_vl = sme_vl;
}
/*
@@ -1320,6 +1763,15 @@ static void fpsimd_flush_cpu_state(void)
{
WARN_ON(!system_supports_fpsimd());
__this_cpu_write(fpsimd_last_state.st, NULL);
+
+ /*
+ * Leaving streaming mode enabled will cause issues for any kernel
+ * NEON and leaving streaming mode or ZA enabled may increase power
+ * consumption.
+ */
+ if (system_supports_sme())
+ sme_smstop();
+
set_thread_flag(TIF_FOREIGN_FPSTATE);
}
@@ -1397,6 +1849,7 @@ EXPORT_SYMBOL(kernel_neon_end);
static DEFINE_PER_CPU(struct user_fpsimd_state, efi_fpsimd_state);
static DEFINE_PER_CPU(bool, efi_fpsimd_state_used);
static DEFINE_PER_CPU(bool, efi_sve_state_used);
+static DEFINE_PER_CPU(bool, efi_sm_state);
/*
* EFI runtime services support functions
@@ -1431,12 +1884,28 @@ void __efi_fpsimd_begin(void)
*/
if (system_supports_sve() && likely(efi_sve_state)) {
char *sve_state = this_cpu_ptr(efi_sve_state);
+ bool ffr = true;
+ u64 svcr;
__this_cpu_write(efi_sve_state_used, true);
+ if (system_supports_sme()) {
+ svcr = read_sysreg_s(SYS_SVCR_EL0);
+
+ if (!system_supports_fa64())
+ ffr = svcr & SYS_SVCR_EL0_SM_MASK;
+
+ __this_cpu_write(efi_sm_state, ffr);
+ }
+
sve_save_state(sve_state + sve_ffr_offset(sve_max_vl()),
&this_cpu_ptr(&efi_fpsimd_state)->fpsr,
- true);
+ ffr);
+
+ if (system_supports_sme())
+ sysreg_clear_set_s(SYS_SVCR_EL0,
+ SYS_SVCR_EL0_SM_MASK, 0);
+
} else {
fpsimd_save_state(this_cpu_ptr(&efi_fpsimd_state));
}
@@ -1459,11 +1928,26 @@ void __efi_fpsimd_end(void)
if (system_supports_sve() &&
likely(__this_cpu_read(efi_sve_state_used))) {
char const *sve_state = this_cpu_ptr(efi_sve_state);
+ bool ffr = true;
+
+ /*
+ * Restore streaming mode; EFI calls are
+ * normal function calls so should not return in
+ * streaming mode.
+ */
+ if (system_supports_sme()) {
+ if (__this_cpu_read(efi_sm_state)) {
+ sysreg_clear_set_s(SYS_SVCR_EL0,
+ 0,
+ SYS_SVCR_EL0_SM_MASK);
+ if (!system_supports_fa64())
+ ffr = efi_sm_state;
+ }
+ }
- sve_set_vq(sve_vq_from_vl(sve_get_vl()) - 1);
sve_load_state(sve_state + sve_ffr_offset(sve_max_vl()),
&this_cpu_ptr(&efi_fpsimd_state)->fpsr,
- true);
+ ffr);
__this_cpu_write(efi_sve_state_used, false);
} else {
@@ -1538,6 +2022,13 @@ static int __init fpsimd_init(void)
if (!cpu_have_named_feature(ASIMD))
pr_notice("Advanced SIMD is not implemented\n");
- return sve_sysctl_init();
+
+ if (cpu_have_named_feature(SME) && !cpu_have_named_feature(SVE))
+ pr_notice("SME is implemented but not SVE\n");
+
+ sve_sysctl_init();
+ sme_sysctl_init();
+
+ return 0;
}
core_initcall(fpsimd_init);
diff --git a/arch/arm64/kernel/process.c b/arch/arm64/kernel/process.c
index 7fa97df55e3a..9734c9fb1a32 100644
--- a/arch/arm64/kernel/process.c
+++ b/arch/arm64/kernel/process.c
@@ -250,6 +250,8 @@ void show_regs(struct pt_regs *regs)
static void tls_thread_flush(void)
{
write_sysreg(0, tpidr_el0);
+ if (system_supports_tpidr2())
+ write_sysreg_s(0, SYS_TPIDR2_EL0);
if (is_compat_task()) {
current->thread.uw.tp_value = 0;
@@ -298,16 +300,42 @@ int arch_dup_task_struct(struct task_struct *dst, struct task_struct *src)
/*
* Detach src's sve_state (if any) from dst so that it does not
- * get erroneously used or freed prematurely. dst's sve_state
+ * get erroneously used or freed prematurely. dst's copies
* will be allocated on demand later on if dst uses SVE.
* For consistency, also clear TIF_SVE here: this could be done
* later in copy_process(), but to avoid tripping up future
- * maintainers it is best not to leave TIF_SVE and sve_state in
+ * maintainers it is best not to leave TIF flags and buffers in
* an inconsistent state, even temporarily.
*/
dst->thread.sve_state = NULL;
clear_tsk_thread_flag(dst, TIF_SVE);
+ /*
+ * In the unlikely event that we create a new thread with ZA
+ * enabled we should retain the ZA state so duplicate it here.
+ * This may be shortly freed if we exec() or if CLONE_SETTLS
+ * but it's simpler to do it here. To avoid confusing the rest
+ * of the code ensure that we have a sve_state allocated
+ * whenever za_state is allocated.
+ */
+ if (thread_za_enabled(&src->thread)) {
+ dst->thread.sve_state = kzalloc(sve_state_size(src),
+ GFP_KERNEL);
+ if (!dst->thread.sve_state)
+ return -ENOMEM;
+ dst->thread.za_state = kmemdup(src->thread.za_state,
+ za_state_size(src),
+ GFP_KERNEL);
+ if (!dst->thread.za_state) {
+ kfree(dst->thread.sve_state);
+ dst->thread.sve_state = NULL;
+ return -ENOMEM;
+ }
+ } else {
+ dst->thread.za_state = NULL;
+ clear_tsk_thread_flag(dst, TIF_SME);
+ }
+
/* clear any pending asynchronous tag fault raised by the parent */
clear_tsk_thread_flag(dst, TIF_MTE_ASYNC_FAULT);
@@ -343,6 +371,8 @@ int copy_thread(unsigned long clone_flags, unsigned long stack_start,
* out-of-sync with the saved value.
*/
*task_user_tls(p) = read_sysreg(tpidr_el0);
+ if (system_supports_tpidr2())
+ p->thread.tpidr2_el0 = read_sysreg_s(SYS_TPIDR2_EL0);
if (stack_start) {
if (is_compat_thread(task_thread_info(p)))
@@ -353,10 +383,12 @@ int copy_thread(unsigned long clone_flags, unsigned long stack_start,
/*
* If a TLS pointer was passed to clone, use it for the new
- * thread.
+ * thread. We also reset TPIDR2 if it's in use.
*/
- if (clone_flags & CLONE_SETTLS)
+ if (clone_flags & CLONE_SETTLS) {
p->thread.uw.tp_value = tls;
+ p->thread.tpidr2_el0 = 0;
+ }
} else {
/*
* A kthread has no context to ERET to, so ensure any buggy
@@ -387,6 +419,8 @@ int copy_thread(unsigned long clone_flags, unsigned long stack_start,
void tls_preserve_current_state(void)
{
*task_user_tls(current) = read_sysreg(tpidr_el0);
+ if (system_supports_tpidr2() && !is_compat_task())
+ current->thread.tpidr2_el0 = read_sysreg_s(SYS_TPIDR2_EL0);
}
static void tls_thread_switch(struct task_struct *next)
@@ -399,6 +433,8 @@ static void tls_thread_switch(struct task_struct *next)
write_sysreg(0, tpidrro_el0);
write_sysreg(*task_user_tls(next), tpidr_el0);
+ if (system_supports_tpidr2())
+ write_sysreg_s(next->thread.tpidr2_el0, SYS_TPIDR2_EL0);
}
/*
diff --git a/arch/arm64/kernel/ptrace.c b/arch/arm64/kernel/ptrace.c
index 230a47b9189e..47d8a7472171 100644
--- a/arch/arm64/kernel/ptrace.c
+++ b/arch/arm64/kernel/ptrace.c
@@ -713,21 +713,51 @@ static int system_call_set(struct task_struct *target,
#ifdef CONFIG_ARM64_SVE
static void sve_init_header_from_task(struct user_sve_header *header,
- struct task_struct *target)
+ struct task_struct *target,
+ enum vec_type type)
{
unsigned int vq;
+ bool active;
+ bool fpsimd_only;
+ enum vec_type task_type;
memset(header, 0, sizeof(*header));
- header->flags = test_tsk_thread_flag(target, TIF_SVE) ?
- SVE_PT_REGS_SVE : SVE_PT_REGS_FPSIMD;
- if (test_tsk_thread_flag(target, TIF_SVE_VL_INHERIT))
- header->flags |= SVE_PT_VL_INHERIT;
+ /* Check if the requested registers are active for the task */
+ if (thread_sm_enabled(&target->thread))
+ task_type = ARM64_VEC_SME;
+ else
+ task_type = ARM64_VEC_SVE;
+ active = (task_type == type);
+
+ switch (type) {
+ case ARM64_VEC_SVE:
+ if (test_tsk_thread_flag(target, TIF_SVE_VL_INHERIT))
+ header->flags |= SVE_PT_VL_INHERIT;
+ fpsimd_only = !test_tsk_thread_flag(target, TIF_SVE);
+ break;
+ case ARM64_VEC_SME:
+ if (test_tsk_thread_flag(target, TIF_SME_VL_INHERIT))
+ header->flags |= SVE_PT_VL_INHERIT;
+ fpsimd_only = false;
+ break;
+ default:
+ WARN_ON_ONCE(1);
+ return;
+ }
- header->vl = task_get_sve_vl(target);
+ if (active) {
+ if (fpsimd_only) {
+ header->flags |= SVE_PT_REGS_FPSIMD;
+ } else {
+ header->flags |= SVE_PT_REGS_SVE;
+ }
+ }
+
+ header->vl = task_get_vl(target, type);
vq = sve_vq_from_vl(header->vl);
- header->max_vl = sve_max_vl();
+ header->max_vl = vec_max_vl(type);
header->size = SVE_PT_SIZE(vq, header->flags);
header->max_size = SVE_PT_SIZE(sve_vq_from_vl(header->max_vl),
SVE_PT_REGS_SVE);
@@ -738,19 +768,17 @@ static unsigned int sve_size_from_header(struct user_sve_header const *header)
return ALIGN(header->size, SVE_VQ_BYTES);
}
-static int sve_get(struct task_struct *target,
- const struct user_regset *regset,
- struct membuf to)
+static int sve_get_common(struct task_struct *target,
+ const struct user_regset *regset,
+ struct membuf to,
+ enum vec_type type)
{
struct user_sve_header header;
unsigned int vq;
unsigned long start, end;
- if (!system_supports_sve())
- return -EINVAL;
-
/* Header */
- sve_init_header_from_task(&header, target);
+ sve_init_header_from_task(&header, target, type);
vq = sve_vq_from_vl(header.vl);
membuf_write(&to, &header, sizeof(header));
@@ -758,49 +786,61 @@ static int sve_get(struct task_struct *target,
if (target == current)
fpsimd_preserve_current_state();
- /* Registers: FPSIMD-only case */
-
BUILD_BUG_ON(SVE_PT_FPSIMD_OFFSET != sizeof(header));
- if ((header.flags & SVE_PT_REGS_MASK) == SVE_PT_REGS_FPSIMD)
+ BUILD_BUG_ON(SVE_PT_SVE_OFFSET != sizeof(header));
+
+ switch ((header.flags & SVE_PT_REGS_MASK)) {
+ case SVE_PT_REGS_FPSIMD:
return __fpr_get(target, regset, to);
- /* Otherwise: full SVE case */
+ case SVE_PT_REGS_SVE:
+ start = SVE_PT_SVE_OFFSET;
+ end = SVE_PT_SVE_FFR_OFFSET(vq) + SVE_PT_SVE_FFR_SIZE(vq);
+ membuf_write(&to, target->thread.sve_state, end - start);
- BUILD_BUG_ON(SVE_PT_SVE_OFFSET != sizeof(header));
- start = SVE_PT_SVE_OFFSET;
- end = SVE_PT_SVE_FFR_OFFSET(vq) + SVE_PT_SVE_FFR_SIZE(vq);
- membuf_write(&to, target->thread.sve_state, end - start);
+ start = end;
+ end = SVE_PT_SVE_FPSR_OFFSET(vq);
+ membuf_zero(&to, end - start);
- start = end;
- end = SVE_PT_SVE_FPSR_OFFSET(vq);
- membuf_zero(&to, end - start);
+ /*
+ * Copy fpsr, and fpcr which must follow contiguously in
+ * struct fpsimd_state:
+ */
+ start = end;
+ end = SVE_PT_SVE_FPCR_OFFSET(vq) + SVE_PT_SVE_FPCR_SIZE;
+ membuf_write(&to, &target->thread.uw.fpsimd_state.fpsr,
+ end - start);
- /*
- * Copy fpsr, and fpcr which must follow contiguously in
- * struct fpsimd_state:
- */
- start = end;
- end = SVE_PT_SVE_FPCR_OFFSET(vq) + SVE_PT_SVE_FPCR_SIZE;
- membuf_write(&to, &target->thread.uw.fpsimd_state.fpsr, end - start);
+ start = end;
+ end = sve_size_from_header(&header);
+ return membuf_zero(&to, end - start);
- start = end;
- end = sve_size_from_header(&header);
- return membuf_zero(&to, end - start);
+ default:
+ return 0;
+ }
}
-static int sve_set(struct task_struct *target,
+static int sve_get(struct task_struct *target,
const struct user_regset *regset,
- unsigned int pos, unsigned int count,
- const void *kbuf, const void __user *ubuf)
+ struct membuf to)
+{
+ if (!system_supports_sve())
+ return -EINVAL;
+
+ return sve_get_common(target, regset, to, ARM64_VEC_SVE);
+}
+
+static int sve_set_common(struct task_struct *target,
+ const struct user_regset *regset,
+ unsigned int pos, unsigned int count,
+ const void *kbuf, const void __user *ubuf,
+ enum vec_type type)
{
int ret;
struct user_sve_header header;
unsigned int vq;
unsigned long start, end;
- if (!system_supports_sve())
- return -EINVAL;
-
/* Header */
if (count < sizeof(header))
return -EINVAL;
@@ -813,13 +853,37 @@ static int sve_set(struct task_struct *target,
* Apart from SVE_PT_REGS_MASK, all SVE_PT_* flags are consumed by
* vec_set_vector_length(), which will also validate them for us:
*/
- ret = vec_set_vector_length(target, ARM64_VEC_SVE, header.vl,
+ ret = vec_set_vector_length(target, type, header.vl,
((unsigned long)header.flags & ~SVE_PT_REGS_MASK) << 16);
if (ret)
goto out;
/* Actual VL set may be less than the user asked for: */
- vq = sve_vq_from_vl(task_get_sve_vl(target));
+ vq = sve_vq_from_vl(task_get_vl(target, type));
+
+ /* Enter/exit streaming mode */
+ if (system_supports_sme()) {
+ u64 old_svcr = target->thread.svcr;
+
+ switch (type) {
+ case ARM64_VEC_SVE:
+ target->thread.svcr &= ~SYS_SVCR_EL0_SM_MASK;
+ break;
+ case ARM64_VEC_SME:
+ target->thread.svcr |= SYS_SVCR_EL0_SM_MASK;
+ break;
+ default:
+ WARN_ON_ONCE(1);
+ return -EINVAL;
+ }
+
+ /*
+ * If we switched then invalidate any existing SVE
+ * state and ensure there's storage.
+ */
+ if (target->thread.svcr != old_svcr)
+ sve_alloc(target);
+ }
/* Registers: FPSIMD-only case */
@@ -828,10 +892,15 @@ static int sve_set(struct task_struct *target,
ret = __fpr_set(target, regset, pos, count, kbuf, ubuf,
SVE_PT_FPSIMD_OFFSET);
clear_tsk_thread_flag(target, TIF_SVE);
+ if (type == ARM64_VEC_SME)
+ fpsimd_force_sync_to_sve(target);
goto out;
}
- /* Otherwise: full SVE case */
+ /*
+ * Otherwise: no registers or full SVE case. For backwards
+ * compatibility reasons we treat empty flags as SVE registers.
+ */
/*
* If setting a different VL from the requested VL and there is
@@ -852,8 +921,9 @@ static int sve_set(struct task_struct *target,
/*
* Ensure target->thread.sve_state is up to date with target's
- * FPSIMD regs, so that a short copyin leaves trailing registers
- * unmodified.
+ * FPSIMD regs, so that a short copyin leaves trailing
+ * registers unmodified. Always enable SVE even if going into
+ * streaming mode.
*/
fpsimd_sync_to_sve(target);
set_tsk_thread_flag(target, TIF_SVE);
@@ -889,8 +959,181 @@ out:
return ret;
}
+static int sve_set(struct task_struct *target,
+ const struct user_regset *regset,
+ unsigned int pos, unsigned int count,
+ const void *kbuf, const void __user *ubuf)
+{
+ if (!system_supports_sve())
+ return -EINVAL;
+
+ return sve_set_common(target, regset, pos, count, kbuf, ubuf,
+ ARM64_VEC_SVE);
+}
+
#endif /* CONFIG_ARM64_SVE */
+#ifdef CONFIG_ARM64_SME
+
+static int ssve_get(struct task_struct *target,
+ const struct user_regset *regset,
+ struct membuf to)
+{
+ if (!system_supports_sme())
+ return -EINVAL;
+
+ return sve_get_common(target, regset, to, ARM64_VEC_SME);
+}
+
+static int ssve_set(struct task_struct *target,
+ const struct user_regset *regset,
+ unsigned int pos, unsigned int count,
+ const void *kbuf, const void __user *ubuf)
+{
+ if (!system_supports_sme())
+ return -EINVAL;
+
+ return sve_set_common(target, regset, pos, count, kbuf, ubuf,
+ ARM64_VEC_SME);
+}
+
+static int za_get(struct task_struct *target,
+ const struct user_regset *regset,
+ struct membuf to)
+{
+ struct user_za_header header;
+ unsigned int vq;
+ unsigned long start, end;
+
+ if (!system_supports_sme())
+ return -EINVAL;
+
+ /* Header */
+ memset(&header, 0, sizeof(header));
+
+ if (test_tsk_thread_flag(target, TIF_SME_VL_INHERIT))
+ header.flags |= ZA_PT_VL_INHERIT;
+
+ header.vl = task_get_sme_vl(target);
+ vq = sve_vq_from_vl(header.vl);
+ header.max_vl = sme_max_vl();
+ header.max_size = ZA_PT_SIZE(vq);
+
+ /* If ZA is not active there is only the header */
+ if (thread_za_enabled(&target->thread))
+ header.size = ZA_PT_SIZE(vq);
+ else
+ header.size = ZA_PT_ZA_OFFSET;
+
+ membuf_write(&to, &header, sizeof(header));
+
+ BUILD_BUG_ON(ZA_PT_ZA_OFFSET != sizeof(header));
+ end = ZA_PT_ZA_OFFSET;
+
+ if (target == current)
+ fpsimd_preserve_current_state();
+
+ /* Any register data to include? */
+ if (thread_za_enabled(&target->thread)) {
+ start = end;
+ end = ZA_PT_SIZE(vq);
+ membuf_write(&to, target->thread.za_state, end - start);
+ }
+
+ /* Zero any trailing padding */
+ start = end;
+ end = ALIGN(header.size, SVE_VQ_BYTES);
+ return membuf_zero(&to, end - start);
+}
+
+static int za_set(struct task_struct *target,
+ const struct user_regset *regset,
+ unsigned int pos, unsigned int count,
+ const void *kbuf, const void __user *ubuf)
+{
+ int ret;
+ struct user_za_header header;
+ unsigned int vq;
+ unsigned long start, end;
+
+ if (!system_supports_sme())
+ return -EINVAL;
+
+ /* Header */
+ if (count < sizeof(header))
+ return -EINVAL;
+ ret = user_regset_copyin(&pos, &count, &kbuf, &ubuf, &header,
+ 0, sizeof(header));
+ if (ret)
+ goto out;
+
+ /*
+ * All current ZA_PT_* flags are consumed by
+ * vec_set_vector_length(), which will also validate them for
+ * us:
+ */
+ ret = vec_set_vector_length(target, ARM64_VEC_SME, header.vl,
+ ((unsigned long)header.flags) << 16);
+ if (ret)
+ goto out;
+
+ /* Actual VL set may be less than the user asked for: */
+ vq = sve_vq_from_vl(task_get_sme_vl(target));
+
+ /* Ensure there is some SVE storage for streaming mode */
+ if (!target->thread.sve_state) {
+ sve_alloc(target);
+ if (!target->thread.sve_state) {
+ clear_thread_flag(TIF_SME);
+ ret = -ENOMEM;
+ goto out;
+ }
+ }
+
+ /* Allocate/reinit ZA storage */
+ sme_alloc(target);
+ if (!target->thread.za_state) {
+ ret = -ENOMEM;
+ clear_tsk_thread_flag(target, TIF_SME);
+ goto out;
+ }
+
+ /* If there is no data then disable ZA */
+ if (!count) {
+ target->thread.svcr &= ~SYS_SVCR_EL0_ZA_MASK;
+ goto out;
+ }
+
+ /*
+ * If setting a different VL from the requested VL and there is
+ * register data, the data layout will be wrong: don't even
+ * try to set the registers in this case.
+ */
+ if (vq != sve_vq_from_vl(header.vl)) {
+ ret = -EIO;
+ goto out;
+ }
+
+ BUILD_BUG_ON(ZA_PT_ZA_OFFSET != sizeof(header));
+ start = ZA_PT_ZA_OFFSET;
+ end = ZA_PT_SIZE(vq);
+ ret = user_regset_copyin(&pos, &count, &kbuf, &ubuf,
+ target->thread.za_state,
+ start, end);
+ if (ret)
+ goto out;
+
+ /* Mark ZA as active and let userspace use it */
+ set_tsk_thread_flag(target, TIF_SME);
+ target->thread.svcr |= SYS_SVCR_EL0_ZA_MASK;
+
+out:
+ fpsimd_flush_task_state(target);
+ return ret;
+}
+
+#endif /* CONFIG_ARM64_SME */
+
#ifdef CONFIG_ARM64_PTR_AUTH
static int pac_mask_get(struct task_struct *target,
const struct user_regset *regset,
@@ -1108,6 +1351,10 @@ enum aarch64_regset {
#ifdef CONFIG_ARM64_SVE
REGSET_SVE,
#endif
+#ifdef CONFIG_ARM64_SVE
+ REGSET_SSVE,
+ REGSET_ZA,
+#endif
#ifdef CONFIG_ARM64_PTR_AUTH
REGSET_PAC_MASK,
REGSET_PAC_ENABLED_KEYS,
@@ -1188,6 +1435,25 @@ static const struct user_regset aarch64_regsets[] = {
.set = sve_set,
},
#endif
+#ifdef CONFIG_ARM64_SME
+ [REGSET_SSVE] = { /* Streaming mode SVE */
+ .core_note_type = NT_ARM_SSVE,
+ .n = DIV_ROUND_UP(SVE_PT_SIZE(SVE_VQ_MAX, SVE_PT_REGS_SVE),
+ SVE_VQ_BYTES),
+ .size = SVE_VQ_BYTES,
+ .align = SVE_VQ_BYTES,
+ .regset_get = ssve_get,
+ .set = ssve_set,
+ },
+ [REGSET_ZA] = { /* SME ZA */
+ .core_note_type = NT_ARM_ZA,
+ .n = DIV_ROUND_UP(ZA_PT_ZA_SIZE(SVE_VQ_MAX), SVE_VQ_BYTES),
+ .size = SVE_VQ_BYTES,
+ .align = SVE_VQ_BYTES,
+ .regset_get = za_get,
+ .set = za_set,
+ },
+#endif
#ifdef CONFIG_ARM64_PTR_AUTH
[REGSET_PAC_MASK] = {
.core_note_type = NT_ARM_PAC_MASK,
diff --git a/arch/arm64/kernel/signal.c b/arch/arm64/kernel/signal.c
index 4a4122ef6f39..2295948d97fd 100644
--- a/arch/arm64/kernel/signal.c
+++ b/arch/arm64/kernel/signal.c
@@ -56,6 +56,7 @@ struct rt_sigframe_user_layout {
unsigned long fpsimd_offset;
unsigned long esr_offset;
unsigned long sve_offset;
+ unsigned long za_offset;
unsigned long extra_offset;
unsigned long end_offset;
};
@@ -218,6 +219,7 @@ static int restore_fpsimd_context(struct fpsimd_context __user *ctx)
struct user_ctxs {
struct fpsimd_context __user *fpsimd;
struct sve_context __user *sve;
+ struct za_context __user *za;
};
#ifdef CONFIG_ARM64_SVE
@@ -226,11 +228,17 @@ static int preserve_sve_context(struct sve_context __user *ctx)
{
int err = 0;
u16 reserved[ARRAY_SIZE(ctx->__reserved)];
+ u16 flags = 0;
unsigned int vl = task_get_sve_vl(current);
unsigned int vq = 0;
- if (test_thread_flag(TIF_SVE))
+ if (thread_sm_enabled(&current->thread)) {
+ vl = task_get_sme_vl(current);
vq = sve_vq_from_vl(vl);
+ flags |= SVE_SIG_FLAG_SM;
+ } else if (test_thread_flag(TIF_SVE)) {
+ vq = sve_vq_from_vl(vl);
+ }
memset(reserved, 0, sizeof(reserved));
@@ -238,6 +246,7 @@ static int preserve_sve_context(struct sve_context __user *ctx)
__put_user_error(round_up(SVE_SIG_CONTEXT_SIZE(vq), 16),
&ctx->head.size, err);
__put_user_error(vl, &ctx->vl, err);
+ __put_user_error(flags, &ctx->flags, err);
BUILD_BUG_ON(sizeof(ctx->__reserved) != sizeof(reserved));
err |= __copy_to_user(&ctx->__reserved, reserved, sizeof(reserved));
@@ -258,18 +267,28 @@ static int preserve_sve_context(struct sve_context __user *ctx)
static int restore_sve_fpsimd_context(struct user_ctxs *user)
{
int err;
- unsigned int vq;
+ unsigned int vl, vq;
struct user_fpsimd_state fpsimd;
struct sve_context sve;
if (__copy_from_user(&sve, user->sve, sizeof(sve)))
return -EFAULT;
- if (sve.vl != task_get_sve_vl(current))
+ if (sve.flags & SVE_SIG_FLAG_SM) {
+ if (!system_supports_sme())
+ return -EINVAL;
+
+ vl = task_get_sme_vl(current);
+ } else {
+ vl = task_get_sve_vl(current);
+ }
+
+ if (sve.vl != vl)
return -EINVAL;
if (sve.head.size <= sizeof(*user->sve)) {
clear_thread_flag(TIF_SVE);
+ current->thread.svcr &= ~SYS_SVCR_EL0_SM_MASK;
goto fpsimd_only;
}
@@ -301,7 +320,10 @@ static int restore_sve_fpsimd_context(struct user_ctxs *user)
if (err)
return -EFAULT;
- set_thread_flag(TIF_SVE);
+ if (sve.flags & SVE_SIG_FLAG_SM)
+ current->thread.svcr |= SYS_SVCR_EL0_SM_MASK;
+ else
+ set_thread_flag(TIF_SVE);
fpsimd_only:
/* copy the FP and status/control registers */
@@ -326,6 +348,101 @@ extern int restore_sve_fpsimd_context(struct user_ctxs *user);
#endif /* ! CONFIG_ARM64_SVE */
+#ifdef CONFIG_ARM64_SME
+
+static int preserve_za_context(struct za_context __user *ctx)
+{
+ int err = 0;
+ u16 reserved[ARRAY_SIZE(ctx->__reserved)];
+ unsigned int vl = task_get_sme_vl(current);
+ unsigned int vq;
+
+ if (thread_za_enabled(&current->thread))
+ vq = sve_vq_from_vl(vl);
+ else
+ vq = 0;
+
+ memset(reserved, 0, sizeof(reserved));
+
+ __put_user_error(ZA_MAGIC, &ctx->head.magic, err);
+ __put_user_error(round_up(ZA_SIG_CONTEXT_SIZE(vq), 16),
+ &ctx->head.size, err);
+ __put_user_error(vl, &ctx->vl, err);
+ BUILD_BUG_ON(sizeof(ctx->__reserved) != sizeof(reserved));
+ err |= __copy_to_user(&ctx->__reserved, reserved, sizeof(reserved));
+
+ if (vq) {
+ /*
+ * This assumes that the ZA state has already been saved to
+ * the task struct by calling the function
+ * fpsimd_signal_preserve_current_state().
+ */
+ err |= __copy_to_user((char __user *)ctx + ZA_SIG_REGS_OFFSET,
+ current->thread.za_state,
+ ZA_SIG_REGS_SIZE(vq));
+ }
+
+ return err ? -EFAULT : 0;
+}
+
+static int restore_za_context(struct user_ctxs __user *user)
+{
+ int err;
+ unsigned int vq;
+ struct za_context za;
+
+ if (__copy_from_user(&za, user->za, sizeof(za)))
+ return -EFAULT;
+
+ if (za.vl != task_get_sme_vl(current))
+ return -EINVAL;
+
+ if (za.head.size <= sizeof(*user->za)) {
+ current->thread.svcr &= ~SYS_SVCR_EL0_ZA_MASK;
+ return 0;
+ }
+
+ vq = sve_vq_from_vl(za.vl);
+
+ if (za.head.size < ZA_SIG_CONTEXT_SIZE(vq))
+ return -EINVAL;
+
+ /*
+ * Careful: we are about __copy_from_user() directly into
+ * thread.za_state with preemption enabled, so protection is
+ * needed to prevent a racing context switch from writing stale
+ * registers back over the new data.
+ */
+
+ fpsimd_flush_task_state(current);
+ /* From now, fpsimd_thread_switch() won't touch thread.sve_state */
+
+ sme_alloc(current);
+ if (!current->thread.za_state) {
+ current->thread.svcr &= ~SYS_SVCR_EL0_ZA_MASK;
+ clear_thread_flag(TIF_SME);
+ return -ENOMEM;
+ }
+
+ err = __copy_from_user(current->thread.za_state,
+ (char __user const *)user->za +
+ ZA_SIG_REGS_OFFSET,
+ ZA_SIG_REGS_SIZE(vq));
+ if (err)
+ return -EFAULT;
+
+ set_thread_flag(TIF_SME);
+ current->thread.svcr |= SYS_SVCR_EL0_ZA_MASK;
+
+ return 0;
+}
+#else /* ! CONFIG_ARM64_SME */
+
+/* Turn any non-optimised out attempts to use these into a link error: */
+extern int preserve_za_context(void __user *ctx);
+extern int restore_za_context(struct user_ctxs *user);
+
+#endif /* ! CONFIG_ARM64_SME */
static int parse_user_sigframe(struct user_ctxs *user,
struct rt_sigframe __user *sf)
@@ -340,6 +457,7 @@ static int parse_user_sigframe(struct user_ctxs *user,
user->fpsimd = NULL;
user->sve = NULL;
+ user->za = NULL;
if (!IS_ALIGNED((unsigned long)base, 16))
goto invalid;
@@ -393,7 +511,7 @@ static int parse_user_sigframe(struct user_ctxs *user,
break;
case SVE_MAGIC:
- if (!system_supports_sve())
+ if (!system_supports_sve() && !system_supports_sme())
goto invalid;
if (user->sve)
@@ -405,6 +523,19 @@ static int parse_user_sigframe(struct user_ctxs *user,
user->sve = (struct sve_context __user *)head;
break;
+ case ZA_MAGIC:
+ if (!system_supports_sme())
+ goto invalid;
+
+ if (user->za)
+ goto invalid;
+
+ if (size < sizeof(*user->za))
+ goto invalid;
+
+ user->za = (struct za_context __user *)head;
+ break;
+
case EXTRA_MAGIC:
if (have_extra_context)
goto invalid;
@@ -528,6 +659,9 @@ static int restore_sigframe(struct pt_regs *regs,
}
}
+ if (err == 0 && system_supports_sme() && user.za)
+ err = restore_za_context(&user);
+
return err;
}
@@ -594,11 +728,12 @@ static int setup_sigframe_layout(struct rt_sigframe_user_layout *user,
if (system_supports_sve()) {
unsigned int vq = 0;
- if (add_all || test_thread_flag(TIF_SVE)) {
- int vl = sve_max_vl();
+ if (add_all || test_thread_flag(TIF_SVE) ||
+ thread_sm_enabled(&current->thread)) {
+ int vl = max(sve_max_vl(), sme_max_vl());
if (!add_all)
- vl = task_get_sve_vl(current);
+ vl = thread_get_cur_vl(&current->thread);
vq = sve_vq_from_vl(vl);
}
@@ -609,6 +744,24 @@ static int setup_sigframe_layout(struct rt_sigframe_user_layout *user,
return err;
}
+ if (system_supports_sme()) {
+ unsigned int vl;
+ unsigned int vq = 0;
+
+ if (add_all)
+ vl = sme_max_vl();
+ else
+ vl = task_get_sme_vl(current);
+
+ if (thread_za_enabled(&current->thread))
+ vq = sve_vq_from_vl(vl);
+
+ err = sigframe_alloc(user, &user->za_offset,
+ ZA_SIG_CONTEXT_SIZE(vq));
+ if (err)
+ return err;
+ }
+
return sigframe_alloc_end(user);
}
@@ -649,13 +802,21 @@ static int setup_sigframe(struct rt_sigframe_user_layout *user,
__put_user_error(current->thread.fault_code, &esr_ctx->esr, err);
}
- /* Scalable Vector Extension state, if present */
- if (system_supports_sve() && err == 0 && user->sve_offset) {
+ /* Scalable Vector Extension state (including streaming), if present */
+ if ((system_supports_sve() || system_supports_sme()) &&
+ err == 0 && user->sve_offset) {
struct sve_context __user *sve_ctx =
apply_user_offset(user, user->sve_offset);
err |= preserve_sve_context(sve_ctx);
}
+ /* ZA state if present */
+ if (system_supports_sme() && err == 0 && user->za_offset) {
+ struct za_context __user *za_ctx =
+ apply_user_offset(user, user->za_offset);
+ err |= preserve_za_context(za_ctx);
+ }
+
if (err == 0 && user->extra_offset) {
char __user *sfp = (char __user *)user->sigframe;
char __user *userp =
@@ -759,6 +920,13 @@ static void setup_return(struct pt_regs *regs, struct k_sigaction *ka,
/* TCO (Tag Check Override) always cleared for signal handlers */
regs->pstate &= ~PSR_TCO_BIT;
+ /* Signal handlers are invoked with ZA and streaming mode disabled */
+ if (system_supports_sme()) {
+ current->thread.svcr &= ~(SYS_SVCR_EL0_ZA_MASK |
+ SYS_SVCR_EL0_SM_MASK);
+ sme_smstop();
+ }
+
if (ka->sa.sa_flags & SA_RESTORER)
sigtramp = ka->sa.sa_restorer;
else
diff --git a/arch/arm64/kernel/syscall.c b/arch/arm64/kernel/syscall.c
index c938603b3ba0..92c69e5ac269 100644
--- a/arch/arm64/kernel/syscall.c
+++ b/arch/arm64/kernel/syscall.c
@@ -158,11 +158,36 @@ trace_exit:
syscall_trace_exit(regs);
}
-static inline void sve_user_discard(void)
+/*
+ * As per the ABI exit SME streaming mode and clear the SVE state not
+ * shared with FPSIMD on syscall entry.
+ */
+static inline void fp_user_discard(void)
{
+ /*
+ * If SME is active then exit streaming mode. If ZA is active
+ * then flush the SVE registers but leave userspace access to
+ * both SVE and SME enabled, otherwise disable SME for the
+ * task and fall through to disabling SVE too. This means
+ * that after a syscall we never have any streaming mode
+ * register state to track, if this changes the KVM code will
+ * need updating.
+ */
+ if (system_supports_sme() && test_thread_flag(TIF_SME)) {
+ u64 svcr = read_sysreg_s(SYS_SVCR_EL0);
+
+ if (svcr & SYS_SVCR_EL0_SM_MASK)
+ sme_smstop_sm();
+ }
+
if (!system_supports_sve())
return;
+ /*
+ * If SME is not active then disable SVE, the registers will
+ * be cleared when userspace next attempts to access them and
+ * we do not need to track the SVE register state until then.
+ */
clear_thread_flag(TIF_SVE);
/*
@@ -177,7 +202,7 @@ static inline void sve_user_discard(void)
void do_el0_svc(struct pt_regs *regs)
{
- sve_user_discard();
+ fp_user_discard();
el0_svc_common(regs, regs->regs[8], __NR_syscalls, sys_call_table);
}
diff --git a/arch/arm64/kernel/traps.c b/arch/arm64/kernel/traps.c
index 0529fd57567e..6751621e5bea 100644
--- a/arch/arm64/kernel/traps.c
+++ b/arch/arm64/kernel/traps.c
@@ -821,6 +821,7 @@ static const char *esr_class_str[] = {
[ESR_ELx_EC_SVE] = "SVE",
[ESR_ELx_EC_ERET] = "ERET/ERETAA/ERETAB",
[ESR_ELx_EC_FPAC] = "FPAC",
+ [ESR_ELx_EC_SME] = "SME",
[ESR_ELx_EC_IMP_DEF] = "EL3 IMP DEF",
[ESR_ELx_EC_IABT_LOW] = "IABT (lower EL)",
[ESR_ELx_EC_IABT_CUR] = "IABT (current EL)",
generated by cgit v1.2.3 (git 2.39.0) at 2024-09-14 22:56:41 +0300