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-rw-r--r--Documentation/admin-guide/kernel-parameters.txt3
-rw-r--r--arch/arm64/include/asm/el2_setup.h24
-rw-r--r--arch/arm64/kernel/cpufeature.c7
-rw-r--r--arch/arm64/kernel/cpuinfo.c7
-rw-r--r--arch/arm64/kernel/pi/idreg-override.c3
5 files changed, 26 insertions, 18 deletions
diff --git a/Documentation/admin-guide/kernel-parameters.txt b/Documentation/admin-guide/kernel-parameters.txt
index 76e538c77e31..c16717dc5e57 100644
--- a/Documentation/admin-guide/kernel-parameters.txt
+++ b/Documentation/admin-guide/kernel-parameters.txt
@@ -458,6 +458,9 @@
arm64.nomops [ARM64] Unconditionally disable Memory Copy and Memory
Set instructions support
+ arm64.nompam [ARM64] Unconditionally disable Memory Partitioning And
+ Monitoring support
+
arm64.nomte [ARM64] Unconditionally disable Memory Tagging Extension
support
diff --git a/arch/arm64/include/asm/el2_setup.h b/arch/arm64/include/asm/el2_setup.h
index 30f57b0334a3..af7807f11df4 100644
--- a/arch/arm64/include/asm/el2_setup.h
+++ b/arch/arm64/include/asm/el2_setup.h
@@ -298,19 +298,6 @@
.Lskip_gcs_\@:
.endm
-.macro __init_el2_mpam
- /* Memory Partitioning And Monitoring: disable EL2 traps */
- mrs x1, id_aa64pfr0_el1
- ubfx x0, x1, #ID_AA64PFR0_EL1_MPAM_SHIFT, #4
- cbz x0, .Lskip_mpam_\@ // skip if no MPAM
- msr_s SYS_MPAM2_EL2, xzr // use the default partition
- // and disable lower traps
- mrs_s x0, SYS_MPAMIDR_EL1
- tbz x0, #MPAMIDR_EL1_HAS_HCR_SHIFT, .Lskip_mpam_\@ // skip if no MPAMHCR reg
- msr_s SYS_MPAMHCR_EL2, xzr // clear TRAP_MPAMIDR_EL1 -> EL2
-.Lskip_mpam_\@:
-.endm
-
/**
* Initialize EL2 registers to sane values. This should be called early on all
* cores that were booted in EL2. Note that everything gets initialised as
@@ -328,7 +315,6 @@
__init_el2_stage2
__init_el2_gicv3
__init_el2_hstr
- __init_el2_mpam
__init_el2_nvhe_idregs
__init_el2_cptr
__init_el2_fgt
@@ -375,6 +361,16 @@
#endif
.macro finalise_el2_state
+ check_override id_aa64pfr0, ID_AA64PFR0_EL1_MPAM_SHIFT, .Linit_mpam_\@, .Lskip_mpam_\@, x1, x2
+
+.Linit_mpam_\@:
+ msr_s SYS_MPAM2_EL2, xzr // use the default partition
+ // and disable lower traps
+ mrs_s x0, SYS_MPAMIDR_EL1
+ tbz x0, #MPAMIDR_EL1_HAS_HCR_SHIFT, .Lskip_mpam_\@ // skip if no MPAMHCR reg
+ msr_s SYS_MPAMHCR_EL2, xzr // clear TRAP_MPAMIDR_EL1 -> EL2
+
+.Lskip_mpam_\@:
check_override id_aa64pfr0, ID_AA64PFR0_EL1_SVE_SHIFT, .Linit_sve_\@, .Lskip_sve_\@, x1, x2
.Linit_sve_\@: /* SVE register access */
diff --git a/arch/arm64/kernel/cpufeature.c b/arch/arm64/kernel/cpufeature.c
index 379c82d22c75..fcc20d13e938 100644
--- a/arch/arm64/kernel/cpufeature.c
+++ b/arch/arm64/kernel/cpufeature.c
@@ -1198,8 +1198,10 @@ void __init init_cpu_features(struct cpuinfo_arm64 *info)
cpacr_restore(cpacr);
}
- if (id_aa64pfr0_mpam(info->reg_id_aa64pfr0))
+ if (id_aa64pfr0_mpam(read_sanitised_ftr_reg(SYS_ID_AA64PFR0_EL1))) {
+ info->reg_mpamidr = read_cpuid(MPAMIDR_EL1);
init_cpu_ftr_reg(SYS_MPAMIDR_EL1, info->reg_mpamidr);
+ }
if (id_aa64pfr1_mte(info->reg_id_aa64pfr1))
init_cpu_ftr_reg(SYS_GMID_EL1, info->reg_gmid);
@@ -1452,7 +1454,8 @@ void update_cpu_features(int cpu,
cpacr_restore(cpacr);
}
- if (id_aa64pfr0_mpam(info->reg_id_aa64pfr0)) {
+ if (id_aa64pfr0_mpam(read_sanitised_ftr_reg(SYS_ID_AA64PFR0_EL1))) {
+ info->reg_mpamidr = read_cpuid(MPAMIDR_EL1);
taint |= check_update_ftr_reg(SYS_MPAMIDR_EL1, cpu,
info->reg_mpamidr, boot->reg_mpamidr);
}
diff --git a/arch/arm64/kernel/cpuinfo.c b/arch/arm64/kernel/cpuinfo.c
index 94525abd1c22..c1f2b6b04b41 100644
--- a/arch/arm64/kernel/cpuinfo.c
+++ b/arch/arm64/kernel/cpuinfo.c
@@ -496,8 +496,11 @@ static void __cpuinfo_store_cpu(struct cpuinfo_arm64 *info)
if (id_aa64pfr0_32bit_el0(info->reg_id_aa64pfr0))
__cpuinfo_store_cpu_32bit(&info->aarch32);
- if (id_aa64pfr0_mpam(info->reg_id_aa64pfr0))
- info->reg_mpamidr = read_cpuid(MPAMIDR_EL1);
+ /*
+ * info->reg_mpamidr deferred to {init,update}_cpu_features because we
+ * don't want to read it (and trigger a trap on buggy firmware) if
+ * using an aa64pfr0_el1 override to unconditionally disable MPAM.
+ */
if (IS_ENABLED(CONFIG_ARM64_SME) &&
id_aa64pfr1_sme(info->reg_id_aa64pfr1)) {
diff --git a/arch/arm64/kernel/pi/idreg-override.c b/arch/arm64/kernel/pi/idreg-override.c
index c6b185b885f7..bc57b290e5e7 100644
--- a/arch/arm64/kernel/pi/idreg-override.c
+++ b/arch/arm64/kernel/pi/idreg-override.c
@@ -127,6 +127,7 @@ static const struct ftr_set_desc pfr0 __prel64_initconst = {
.fields = {
FIELD("sve", ID_AA64PFR0_EL1_SVE_SHIFT, pfr0_sve_filter),
FIELD("el0", ID_AA64PFR0_EL1_EL0_SHIFT, NULL),
+ FIELD("mpam", ID_AA64PFR0_EL1_MPAM_SHIFT, NULL),
{}
},
};
@@ -154,6 +155,7 @@ static const struct ftr_set_desc pfr1 __prel64_initconst = {
FIELD("gcs", ID_AA64PFR1_EL1_GCS_SHIFT, NULL),
FIELD("mte", ID_AA64PFR1_EL1_MTE_SHIFT, NULL),
FIELD("sme", ID_AA64PFR1_EL1_SME_SHIFT, pfr1_sme_filter),
+ FIELD("mpam_frac", ID_AA64PFR1_EL1_MPAM_frac_SHIFT, NULL),
{}
},
};
@@ -246,6 +248,7 @@ static const struct {
{ "rodata=off", "arm64_sw.rodataoff=1" },
{ "arm64.nolva", "id_aa64mmfr2.varange=0" },
{ "arm64.no32bit_el0", "id_aa64pfr0.el0=1" },
+ { "arm64.nompam", "id_aa64pfr0.mpam=0 id_aa64pfr1.mpam_frac=0" },
};
static int __init parse_hexdigit(const char *p, u64 *v)