From 3e0c373749d7eb5b354ac0b043f2b2cdf84eefef Mon Sep 17 00:00:00 2001 From: Yinghai Lu Date: Sat, 9 May 2009 23:47:42 -0700 Subject: x86: clean up and fix setup_clear/force_cpu_cap handling setup_force_cpu_cap() only have one user (Xen guest code), but it should not reuse cleared_cpu_cpus, otherwise it will have problems on SMP. Need to have a separate cpu_cpus_set array too, for forced-on flags, beyond the forced-off flags. Also need to setup handling before all cpus caps are combined. [ Impact: fix the forced-set CPU feature flag logic ] Cc: H. Peter Anvin Cc: Jeremy Fitzhardinge Cc: Rusty Russell Signed-off-by: Yinghai Lu LKML-Reference: Signed-off-by: Ingo Molnar --- arch/x86/kernel/cpu/common.c | 17 ++++++++++++----- 1 file changed, 12 insertions(+), 5 deletions(-) (limited to 'arch/x86/kernel/cpu/common.c') diff --git a/arch/x86/kernel/cpu/common.c b/arch/x86/kernel/cpu/common.c index c4f667896c28..e7fd5c4935a3 100644 --- a/arch/x86/kernel/cpu/common.c +++ b/arch/x86/kernel/cpu/common.c @@ -292,7 +292,8 @@ static const char *__cpuinit table_lookup_model(struct cpuinfo_x86 *c) return NULL; /* Not found */ } -__u32 cleared_cpu_caps[NCAPINTS] __cpuinitdata; +__u32 cpu_caps_cleared[NCAPINTS] __cpuinitdata; +__u32 cpu_caps_set[NCAPINTS] __cpuinitdata; void load_percpu_segment(int cpu) { @@ -806,6 +807,16 @@ static void __cpuinit identify_cpu(struct cpuinfo_x86 *c) #endif init_hypervisor(c); + + /* + * Clear/Set all flags overriden by options, need do it + * before following smp all cpus cap AND. + */ + for (i = 0; i < NCAPINTS; i++) { + c->x86_capability[i] &= ~cpu_caps_cleared[i]; + c->x86_capability[i] |= cpu_caps_set[i]; + } + /* * On SMP, boot_cpu_data holds the common feature set between * all CPUs; so make sure that we indicate which features are @@ -818,10 +829,6 @@ static void __cpuinit identify_cpu(struct cpuinfo_x86 *c) boot_cpu_data.x86_capability[i] &= c->x86_capability[i]; } - /* Clear all flags overriden by options */ - for (i = 0; i < NCAPINTS; i++) - c->x86_capability[i] &= ~cleared_cpu_caps[i]; - #ifdef CONFIG_X86_MCE /* Init Machine Check Exception if available. */ mcheck_init(c); -- cgit v1.2.3 From 2759c3287de27266e06f1f4e82cbd2d65f6a044c Mon Sep 17 00:00:00 2001 From: Yinghai Lu Date: Fri, 15 May 2009 13:05:16 -0700 Subject: x86: don't call read_apic_id if !cpu_has_apic should not call that if apic is disabled. [ Impact: fix crash on certain UP configs ] Signed-off-by: Yinghai Lu Cc: Cyrill Gorcunov LKML-Reference: <4A09CCBB.2000306@kernel.org> Signed-off-by: Ingo Molnar --- arch/x86/kernel/cpu/common.c | 6 ++++++ 1 file changed, 6 insertions(+) (limited to 'arch/x86/kernel/cpu/common.c') diff --git a/arch/x86/kernel/cpu/common.c b/arch/x86/kernel/cpu/common.c index c1caefc82e62..017c600e05ab 100644 --- a/arch/x86/kernel/cpu/common.c +++ b/arch/x86/kernel/cpu/common.c @@ -761,6 +761,12 @@ static void __cpuinit identify_cpu(struct cpuinfo_x86 *c) if (this_cpu->c_identify) this_cpu->c_identify(c); + /* Clear/Set all flags overriden by options, after probe */ + for (i = 0; i < NCAPINTS; i++) { + c->x86_capability[i] &= ~cpu_caps_cleared[i]; + c->x86_capability[i] |= cpu_caps_set[i]; + } + #ifdef CONFIG_X86_64 c->apicid = apic->phys_pkg_id(c->initial_apicid, 0); #endif -- cgit v1.2.3 From 0c752a93353d9b17dbe148312d732fbe06d235e1 Mon Sep 17 00:00:00 2001 From: Suresh Siddha Date: Fri, 22 May 2009 12:17:45 -0700 Subject: x86: introduce noxsave boot parameter Introduce "noxsave" boot parameter which will disable the cpu's xsave/xrstor capabilities. Useful for debugging and working around xsave related issues. [ Impact: make it possible to debug problems in the field ] Signed-off-by: Suresh Siddha Signed-off-by: H. Peter Anvin --- arch/x86/kernel/cpu/common.c | 7 +++++++ 1 file changed, 7 insertions(+) (limited to 'arch/x86/kernel/cpu/common.c') diff --git a/arch/x86/kernel/cpu/common.c b/arch/x86/kernel/cpu/common.c index c1caefc82e62..77848d9fca68 100644 --- a/arch/x86/kernel/cpu/common.c +++ b/arch/x86/kernel/cpu/common.c @@ -114,6 +114,13 @@ DEFINE_PER_CPU_PAGE_ALIGNED(struct gdt_page, gdt_page) = { .gdt = { } }; EXPORT_PER_CPU_SYMBOL_GPL(gdt_page); +static int __init x86_xsave_setup(char *s) +{ + setup_clear_cpu_cap(X86_FEATURE_XSAVE); + return 1; +} +__setup("noxsave", x86_xsave_setup); + #ifdef CONFIG_X86_32 static int cachesize_override __cpuinitdata = -1; static int disable_x86_serial_nr __cpuinitdata = 1; -- cgit v1.2.3