mirrors/linux-stable
1
0
Fork 0
mirror of https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git synced 2024-09-28 05:12:49 +00:00
Code Issues Releases Wiki Activity

arm64: cpufeature: Display the set of cores with a feature

Browse source 
The AMU feature can be enabled on a subset of the cores in a system.
Because of that, it prints a message for each core as it is detected.
This becomes tedious when there are hundreds of cores. Instead, for
CPU features which can be enabled on a subset of the present cores,
lets wait until update_cpu_capabilities() and print the subset of cores
the feature was enabled on.

Signed-off-by: Jeremy Linton <jeremy.linton@arm.com>
Reviewed-by: Ionela Voinescu <ionela.voinescu@arm.com>
Tested-by: Ionela Voinescu <ionela.voinescu@arm.com>
Reviewed-by: Punit Agrawal <punit.agrawal@bytedance.com>
Tested-by: Punit Agrawal <punit.agrawal@bytedance.com>
Link: https://lore.kernel.org/r/20231017052322.1211099-2-jeremy.linton@arm.com
Signed-off-by: Catalin Marinas <catalin.marinas@arm.com>
This commit is contained in:
Jeremy Linton 2023-10-17 00:23:20 -05:00 committed by Catalin Marinas
parent 6465e260f4
commit 23b727dc20
2 changed files with 15 additions and 9 deletions
Show stats Download patch file Download diff file Expand all files Collapse all files

2
arch/arm64/include/asm/cpufeature.h
View file

@ -23,6 +23,7 @@
#include <linux/bug.h>
#include <linux/jump_label.h>
#include <linux/kernel.h>
#include <linux/cpumask.h>
/*
* CPU feature register tracking
@ -380,6 +381,7 @@ struct arm64_cpu_capabilities {
* method is robust against being called multiple times.
*/
const struct arm64_cpu_capabilities *match_list;
const struct cpumask *cpus;
};
static inline int cpucap_default_scope(const struct arm64_cpu_capabilities *cap)

22
arch/arm64/kernel/cpufeature.c
View file

@ -1944,8 +1944,6 @@ int get_cpu_with_amu_feat(void)
static void cpu_amu_enable(struct arm64_cpu_capabilities const *cap)
{
if (has_cpuid_feature(cap, SCOPE_LOCAL_CPU)) {
pr_info("detected CPU%d: Activity Monitors Unit (AMU)\n",
smp_processor_id());
cpumask_set_cpu(smp_processor_id(), &amu_cpus);
/* 0 reference values signal broken/disabled counters */
@ -2405,16 +2403,12 @@ static const struct arm64_cpu_capabilities arm64_features[] = {
#endif /* CONFIG_ARM64_RAS_EXTN */
#ifdef CONFIG_ARM64_AMU_EXTN
{
/*
* The feature is enabled by default if CONFIG_ARM64_AMU_EXTN=y.
* Therefore, don't provide .desc as we don't want the detection
* message to be shown until at least one CPU is detected to
* support the feature.
*/
.desc = "Activity Monitors Unit (AMU)",
.capability = ARM64_HAS_AMU_EXTN,
.type = ARM64_CPUCAP_WEAK_LOCAL_CPU_FEATURE,
.matches = has_amu,
.cpu_enable = cpu_amu_enable,
.cpus = &amu_cpus,
ARM64_CPUID_FIELDS(ID_AA64PFR0_EL1, AMU, IMP)
},
#endif /* CONFIG_ARM64_AMU_EXTN */
@ -2981,7 +2975,7 @@ static void update_cpu_capabilities(u16 scope_mask)
!caps->matches(caps, cpucap_default_scope(caps)))
continue;
if (caps->desc)
if (caps->desc && !caps->cpus)
pr_info("detected: %s\n", caps->desc);
__set_bit(caps->capability, system_cpucaps);
@ -3330,6 +3324,7 @@ unsigned long cpu_get_elf_hwcap2(void)
static void __init setup_system_capabilities(void)
{
int i;
/*
* We have finalised the system-wide safe feature
* registers, finalise the capabilities that depend
@ -3338,6 +3333,15 @@ static void __init setup_system_capabilities(void)
*/
update_cpu_capabilities(SCOPE_SYSTEM);
enable_cpu_capabilities(SCOPE_ALL & ~SCOPE_BOOT_CPU);
for (i = 0; i < ARM64_NCAPS; i++) {
const struct arm64_cpu_capabilities *caps = cpucap_ptrs[i];
if (caps && caps->cpus && caps->desc &&
cpumask_any(caps->cpus) < nr_cpu_ids)
pr_info("detected: %s on CPU%*pbl\n",
caps->desc, cpumask_pr_args(caps->cpus));
}
}
void __init setup_cpu_features(void)