[PATCH v2 06/38] arm64: Rework setup_cpu_features()
Mark Rutland
mark.rutland at arm.com
Thu Oct 5 02:49:52 PDT 2023
Currently setup_cpu_features() handles a mixture of one-time kernel
feature setup (e.g. cpucaps) and one-time user feature setup (e.g. ELF
hwcaps). Subsequent patches will rework other one-time setup and expand
the logic currently in setup_cpu_features(), and in preparation for this
it would be helpful to split the kernel and user setup into separate
functions.
This patch splits setup_user_features() out of setup_cpu_features(),
with a few additional cleanups of note:
* setup_cpu_features() is renamed to setup_system_features() to make it
clear that it handles system-wide feature setup rather than cpu-local
feature setup.
* setup_system_capabilities() is folded into setup_system_features().
* Presence of TTBR0 pan is logged immediately after
update_cpu_capabilities(), so that this is guaranteed to appear
alongside all the other detected system cpucaps.
* The 'cwg' variable is removed as its value is only consumed once and
it's simpler to use cache_type_cwg() directly without assigning its
return value to a variable.
* The call to setup_user_features() is moved after alternatives are
patched, which will allow user feature setup code to depend on
alternative branches and allow for simplifications in subsequent
patches.
Signed-off-by: Mark Rutland <mark.rutland at arm.com>
Reviewed-by: Suzuki K Poulose <suzuki.poulose at arm.com>
Cc: Catalin Marinas <catalin.marinas at arm.com>
Cc: Marc Zyngier <maz at kernel.org>
Cc: Mark Brown <broonie at kernel.org>
Cc: Will Deacon <will at kernel.org>
---
arch/arm64/include/asm/cpufeature.h | 4 ++-
arch/arm64/kernel/cpufeature.c | 43 ++++++++++++++---------------
arch/arm64/kernel/smp.c | 3 +-
3 files changed, 26 insertions(+), 24 deletions(-)
diff --git a/arch/arm64/include/asm/cpufeature.h b/arch/arm64/include/asm/cpufeature.h
index ba7c60c9ac695..1233a8ff96a88 100644
--- a/arch/arm64/include/asm/cpufeature.h
+++ b/arch/arm64/include/asm/cpufeature.h
@@ -649,7 +649,9 @@ static inline bool id_aa64pfr1_mte(u64 pfr1)
return val >= ID_AA64PFR1_EL1_MTE_MTE2;
}
-void __init setup_cpu_features(void);
+void __init setup_system_features(void);
+void __init setup_user_features(void);
+
void check_local_cpu_capabilities(void);
u64 read_sanitised_ftr_reg(u32 id);
diff --git a/arch/arm64/kernel/cpufeature.c b/arch/arm64/kernel/cpufeature.c
index 444a73c2e6385..234cf3189bee0 100644
--- a/arch/arm64/kernel/cpufeature.c
+++ b/arch/arm64/kernel/cpufeature.c
@@ -3328,23 +3328,35 @@ unsigned long cpu_get_elf_hwcap2(void)
return elf_hwcap[1];
}
-static void __init setup_system_capabilities(void)
+void __init setup_system_features(void)
{
/*
- * We have finalised the system-wide safe feature
- * registers, finalise the capabilities that depend
- * on it. Also enable all the available capabilities,
- * that are not enabled already.
+ * The system-wide safe feature feature register values have been
+ * finalized. Finalize and log the available system capabilities.
*/
update_cpu_capabilities(SCOPE_SYSTEM);
+ if (system_uses_ttbr0_pan())
+ pr_info("emulated: Privileged Access Never (PAN) using TTBR0_EL1 switching\n");
+
+ /*
+ * Enable all the available capabilities which have not been enabled
+ * already.
+ */
enable_cpu_capabilities(SCOPE_ALL & ~SCOPE_BOOT_CPU);
+
+ sve_setup();
+ sme_setup();
+
+ /*
+ * Check for sane CTR_EL0.CWG value.
+ */
+ if (!cache_type_cwg())
+ pr_warn("No Cache Writeback Granule information, assuming %d\n",
+ ARCH_DMA_MINALIGN);
}
-void __init setup_cpu_features(void)
+void __init setup_user_features(void)
{
- u32 cwg;
-
- setup_system_capabilities();
setup_elf_hwcaps(arm64_elf_hwcaps);
if (system_supports_32bit_el0()) {
@@ -3352,20 +3364,7 @@ void __init setup_cpu_features(void)
elf_hwcap_fixup();
}
- if (system_uses_ttbr0_pan())
- pr_info("emulated: Privileged Access Never (PAN) using TTBR0_EL1 switching\n");
-
- sve_setup();
- sme_setup();
minsigstksz_setup();
-
- /*
- * Check for sane CTR_EL0.CWG value.
- */
- cwg = cache_type_cwg();
- if (!cwg)
- pr_warn("No Cache Writeback Granule information, assuming %d\n",
- ARCH_DMA_MINALIGN);
}
static int enable_mismatched_32bit_el0(unsigned int cpu)
diff --git a/arch/arm64/kernel/smp.c b/arch/arm64/kernel/smp.c
index 960b98b43506d..e0cdf6820f9e9 100644
--- a/arch/arm64/kernel/smp.c
+++ b/arch/arm64/kernel/smp.c
@@ -431,9 +431,10 @@ static void __init hyp_mode_check(void)
void __init smp_cpus_done(unsigned int max_cpus)
{
pr_info("SMP: Total of %d processors activated.\n", num_online_cpus());
- setup_cpu_features();
+ setup_system_features();
hyp_mode_check();
apply_alternatives_all();
+ setup_user_features();
mark_linear_text_alias_ro();
}
--
2.30.2
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