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| author | Pavel Tatashin <pasha.tatashin@oracle.com> | 2018-07-19 16:55:28 -0400 |
|---|---|---|
| committer | Thomas Gleixner <tglx@linutronix.de> | 2018-07-20 00:02:38 +0200 |
| commit | 8990cac6e5ea7fa57607736019fe8dca961b998f (patch) | |
| tree | 66e9d68bab7beb5e9f6c3890010b33161e6bb897 /arch/x86/kernel/cpu/amd.c | |
| parent | 6fffacb30349e0903602d664f7ab6fc87e85162e (diff) | |
| download | lwn-8990cac6e5ea7fa57607736019fe8dca961b998f.tar.gz lwn-8990cac6e5ea7fa57607736019fe8dca961b998f.zip | |
x86/jump_label: Initialize static branching early
Static branching is useful to runtime patch branches that are used in hot
path, but are infrequently changed.
The x86 clock framework is one example that uses static branches to setup
the best clock during boot and never changes it again.
It is desired to enable the TSC based sched clock early to allow fine
grained boot time analysis early on. That requires the static branching
functionality to be functional early as well.
Static branching requires patching nop instructions, thus,
arch_init_ideal_nops() must be called prior to jump_label_init().
Do all the necessary steps to call arch_init_ideal_nops() right after
early_cpu_init(), which also allows to insert a call to jump_label_init()
right after that. jump_label_init() will be called again from the generic
init code, but the code is protected against reinitialization already.
[ tglx: Massaged changelog ]
Suggested-by: Peter Zijlstra <peterz@infradead.org>
Signed-off-by: Pavel Tatashin <pasha.tatashin@oracle.com>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Reviewed-by: Borislav Petkov <bp@suse.de>
Cc: steven.sistare@oracle.com
Cc: daniel.m.jordan@oracle.com
Cc: linux@armlinux.org.uk
Cc: schwidefsky@de.ibm.com
Cc: heiko.carstens@de.ibm.com
Cc: john.stultz@linaro.org
Cc: sboyd@codeaurora.org
Cc: hpa@zytor.com
Cc: douly.fnst@cn.fujitsu.com
Cc: prarit@redhat.com
Cc: feng.tang@intel.com
Cc: pmladek@suse.com
Cc: gnomes@lxorguk.ukuu.org.uk
Cc: linux-s390@vger.kernel.org
Cc: boris.ostrovsky@oracle.com
Cc: jgross@suse.com
Cc: pbonzini@redhat.com
Link: https://lkml.kernel.org/r/20180719205545.16512-10-pasha.tatashin@oracle.com
Diffstat (limited to 'arch/x86/kernel/cpu/amd.c')
| -rw-r--r-- | arch/x86/kernel/cpu/amd.c | 13 |
1 files changed, 8 insertions, 5 deletions
diff --git a/arch/x86/kernel/cpu/amd.c b/arch/x86/kernel/cpu/amd.c index 38915fbfae73..b732438c1a1e 100644 --- a/arch/x86/kernel/cpu/amd.c +++ b/arch/x86/kernel/cpu/amd.c @@ -232,8 +232,6 @@ static void init_amd_k7(struct cpuinfo_x86 *c) } } - set_cpu_cap(c, X86_FEATURE_K7); - /* calling is from identify_secondary_cpu() ? */ if (!c->cpu_index) return; @@ -617,6 +615,14 @@ static void early_init_amd(struct cpuinfo_x86 *c) early_init_amd_mc(c); +#ifdef CONFIG_X86_32 + if (c->x86 == 6) + set_cpu_cap(c, X86_FEATURE_K7); +#endif + + if (c->x86 >= 0xf) + set_cpu_cap(c, X86_FEATURE_K8); + rdmsr_safe(MSR_AMD64_PATCH_LEVEL, &c->microcode, &dummy); /* @@ -863,9 +869,6 @@ static void init_amd(struct cpuinfo_x86 *c) init_amd_cacheinfo(c); - if (c->x86 >= 0xf) - set_cpu_cap(c, X86_FEATURE_K8); - if (cpu_has(c, X86_FEATURE_XMM2)) { unsigned long long val; int ret; |