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-rw-r--r--arch/riscv/kernel/alternative.c19
-rw-r--r--arch/riscv/kernel/cpufeature.c3
-rw-r--r--arch/riscv/kernel/smpboot.c1
-rw-r--r--arch/riscv/kernel/sys_riscv.c28
4 files changed, 51 insertions, 0 deletions
diff --git a/arch/riscv/kernel/alternative.c b/arch/riscv/kernel/alternative.c
index 2354c69dc7d1..fc65c9293ac5 100644
--- a/arch/riscv/kernel/alternative.c
+++ b/arch/riscv/kernel/alternative.c
@@ -27,6 +27,8 @@ struct cpu_manufacturer_info_t {
void (*patch_func)(struct alt_entry *begin, struct alt_entry *end,
unsigned long archid, unsigned long impid,
unsigned int stage);
+ void (*feature_probe_func)(unsigned int cpu, unsigned long archid,
+ unsigned long impid);
};
static void __init_or_module riscv_fill_cpu_mfr_info(struct cpu_manufacturer_info_t *cpu_mfr_info)
@@ -41,6 +43,7 @@ static void __init_or_module riscv_fill_cpu_mfr_info(struct cpu_manufacturer_inf
cpu_mfr_info->imp_id = sbi_get_mimpid();
#endif
+ cpu_mfr_info->feature_probe_func = NULL;
switch (cpu_mfr_info->vendor_id) {
#ifdef CONFIG_ERRATA_SIFIVE
case SIFIVE_VENDOR_ID:
@@ -50,6 +53,7 @@ static void __init_or_module riscv_fill_cpu_mfr_info(struct cpu_manufacturer_inf
#ifdef CONFIG_ERRATA_THEAD
case THEAD_VENDOR_ID:
cpu_mfr_info->patch_func = thead_errata_patch_func;
+ cpu_mfr_info->feature_probe_func = thead_feature_probe_func;
break;
#endif
default:
@@ -139,6 +143,20 @@ void riscv_alternative_fix_offsets(void *alt_ptr, unsigned int len,
}
}
+/* Called on each CPU as it starts */
+void __init_or_module probe_vendor_features(unsigned int cpu)
+{
+ struct cpu_manufacturer_info_t cpu_mfr_info;
+
+ riscv_fill_cpu_mfr_info(&cpu_mfr_info);
+ if (!cpu_mfr_info.feature_probe_func)
+ return;
+
+ cpu_mfr_info.feature_probe_func(cpu,
+ cpu_mfr_info.arch_id,
+ cpu_mfr_info.imp_id);
+}
+
/*
* This is called very early in the boot process (directly after we run
* a feature detect on the boot CPU). No need to worry about other CPUs
@@ -193,6 +211,7 @@ void __init apply_boot_alternatives(void)
/* If called on non-boot cpu things could go wrong */
WARN_ON(smp_processor_id() != 0);
+ probe_vendor_features(0);
_apply_alternatives((struct alt_entry *)__alt_start,
(struct alt_entry *)__alt_end,
RISCV_ALTERNATIVES_BOOT);
diff --git a/arch/riscv/kernel/cpufeature.c b/arch/riscv/kernel/cpufeature.c
index 59d58ee0f68d..8bbc89351050 100644
--- a/arch/riscv/kernel/cpufeature.c
+++ b/arch/riscv/kernel/cpufeature.c
@@ -30,6 +30,9 @@ unsigned long elf_hwcap __read_mostly;
/* Host ISA bitmap */
static DECLARE_BITMAP(riscv_isa, RISCV_ISA_EXT_MAX) __read_mostly;
+/* Performance information */
+DEFINE_PER_CPU(long, misaligned_access_speed);
+
/**
* riscv_isa_extension_base() - Get base extension word
*
diff --git a/arch/riscv/kernel/smpboot.c b/arch/riscv/kernel/smpboot.c
index ddb2afba6d25..2867c12c3d16 100644
--- a/arch/riscv/kernel/smpboot.c
+++ b/arch/riscv/kernel/smpboot.c
@@ -168,6 +168,7 @@ asmlinkage __visible void smp_callin(void)
notify_cpu_starting(curr_cpuid);
numa_add_cpu(curr_cpuid);
set_cpu_online(curr_cpuid, 1);
+ probe_vendor_features(curr_cpuid);
/*
* Remote TLB flushes are ignored while the CPU is offline, so emit
diff --git a/arch/riscv/kernel/sys_riscv.c b/arch/riscv/kernel/sys_riscv.c
index 5ca567cef142..55389e7595f6 100644
--- a/arch/riscv/kernel/sys_riscv.c
+++ b/arch/riscv/kernel/sys_riscv.c
@@ -7,6 +7,7 @@
#include <linux/syscalls.h>
#include <asm/cacheflush.h>
+#include <asm/cpufeature.h>
#include <asm/hwprobe.h>
#include <asm/sbi.h>
#include <asm/switch_to.h>
@@ -117,6 +118,29 @@ static void hwprobe_arch_id(struct riscv_hwprobe *pair,
pair->value = id;
}
+static u64 hwprobe_misaligned(const struct cpumask *cpus)
+{
+ int cpu;
+ u64 perf = -1ULL;
+
+ for_each_cpu(cpu, cpus) {
+ int this_perf = per_cpu(misaligned_access_speed, cpu);
+
+ if (perf == -1ULL)
+ perf = this_perf;
+
+ if (perf != this_perf) {
+ perf = RISCV_HWPROBE_MISALIGNED_UNKNOWN;
+ break;
+ }
+ }
+
+ if (perf == -1ULL)
+ return RISCV_HWPROBE_MISALIGNED_UNKNOWN;
+
+ return perf;
+}
+
static void hwprobe_one_pair(struct riscv_hwprobe *pair,
const struct cpumask *cpus)
{
@@ -146,6 +170,10 @@ static void hwprobe_one_pair(struct riscv_hwprobe *pair,
break;
+ case RISCV_HWPROBE_KEY_CPUPERF_0:
+ pair->value = hwprobe_misaligned(cpus);
+ break;
+
/*
* For forward compatibility, unknown keys don't fail the whole
* call, but get their element key set to -1 and value set to 0