From 123aa76ec0cab5d4881cd8509faed43231e68801 Mon Sep 17 00:00:00 2001 From: Andi Kleen Date: Thu, 12 Feb 2009 13:39:27 +0100 Subject: x86, mce: don't disable machine checks during code patching Impact: low priority bug fix This removes part of a a patch I added myself some time ago. After some consideration the patch was a bad idea. In particular it stopped machine check exceptions during code patching. To quote the comment: * MCEs only happen when something got corrupted and in this * case we must do something about the corruption. * Ignoring it is worse than a unlikely patching race. * Also machine checks tend to be broadcast and if one CPU * goes into machine check the others follow quickly, so we don't * expect a machine check to cause undue problems during to code * patching. So undo the machine check related parts of 8f4e956b313dcccbc7be6f10808952345e3b638c NMIs are still disabled. This only removes code, the only additions are a new comment. Signed-off-by: Andi Kleen Acked-by: Thomas Gleixner Signed-off-by: H. Peter Anvin --- arch/x86/include/asm/mce.h | 2 -- 1 file changed, 2 deletions(-) (limited to 'arch/x86/include') diff --git a/arch/x86/include/asm/mce.h b/arch/x86/include/asm/mce.h index 32c6e17b960b..5522273a3ad8 100644 --- a/arch/x86/include/asm/mce.h +++ b/arch/x86/include/asm/mce.h @@ -120,8 +120,6 @@ extern void mcheck_init(struct cpuinfo_x86 *c); #else #define mcheck_init(c) do { } while (0) #endif -extern void stop_mce(void); -extern void restart_mce(void); #endif /* __KERNEL__ */ #endif /* _ASM_X86_MCE_H */ -- cgit v1.2.2 From b5f2fa4ea00a179ac1c2ff342ceeee261dd75e53 Mon Sep 17 00:00:00 2001 From: Andi Kleen Date: Thu, 12 Feb 2009 13:43:22 +0100 Subject: x86, mce: factor out duplicated struct mce setup into one function Impact: cleanup This merely factors out duplicated code to set up the initial struct mce state into a single function. Signed-off-by: Andi Kleen Signed-off-by: H. Peter Anvin --- arch/x86/include/asm/mce.h | 3 ++- 1 file changed, 2 insertions(+), 1 deletion(-) (limited to 'arch/x86/include') diff --git a/arch/x86/include/asm/mce.h b/arch/x86/include/asm/mce.h index 5522273a3ad8..048b71d9387a 100644 --- a/arch/x86/include/asm/mce.h +++ b/arch/x86/include/asm/mce.h @@ -90,6 +90,7 @@ extern int mce_disabled; #include +void mce_setup(struct mce *m); void mce_log(struct mce *m); DECLARE_PER_CPU(struct sys_device, device_mce); extern void (*threshold_cpu_callback)(unsigned long action, unsigned int cpu); @@ -106,7 +107,7 @@ void mce_amd_feature_init(struct cpuinfo_x86 *c); static inline void mce_amd_feature_init(struct cpuinfo_x86 *c) { } #endif -void mce_log_therm_throt_event(unsigned int cpu, __u64 status); +void mce_log_therm_throt_event(__u64 status); extern atomic_t mce_entry; -- cgit v1.2.2 From b79109c3bbcf52cac5103979b283b9e5df4e796c Mon Sep 17 00:00:00 2001 From: Andi Kleen Date: Thu, 12 Feb 2009 13:43:23 +0100 Subject: x86, mce: separate correct machine check poller and fatal exception handler Impact: cleanup, performance enhancement The machine check poller is diverging more and more from the fatal exception handler. Instead of adding more special cases separate the code paths completely. The corrected poll path is actually quite simple, and this doesn't result in much code duplication. This makes both handlers much easier to read and results in cleaner code flow. The exception handler now only needs to care about uncorrected errors, which also simplifies the handling of multiple errors. The corrected poller also now always runs in standard interrupt context and does not need to do anything special to handle NMI context. Minor behaviour changes: - MCG status is now not cleared on polling. - Only the banks which had corrected errors get cleared on polling - The exception handler only clears banks with errors now v2: Forward port to new patch order. Add "uc" argument. Signed-off-by: Andi Kleen Signed-off-by: H. Peter Anvin --- arch/x86/include/asm/mce.h | 7 +++++++ 1 file changed, 7 insertions(+) (limited to 'arch/x86/include') diff --git a/arch/x86/include/asm/mce.h b/arch/x86/include/asm/mce.h index 048b71d9387a..225cdb5d2bfc 100644 --- a/arch/x86/include/asm/mce.h +++ b/arch/x86/include/asm/mce.h @@ -112,6 +112,13 @@ void mce_log_therm_throt_event(__u64 status); extern atomic_t mce_entry; extern void do_machine_check(struct pt_regs *, long); + +enum mcp_flags { + MCP_TIMESTAMP = (1 << 0), /* log time stamp */ + MCP_UC = (1 << 1), /* log uncorrected errors */ +}; +extern void machine_check_poll(enum mcp_flags flags); + extern int mce_notify_user(void); #endif /* !CONFIG_X86_32 */ -- cgit v1.2.2 From 41fdff322e26c4a86fe65cf577f2556a650cb7bc Mon Sep 17 00:00:00 2001 From: Andi Kleen Date: Thu, 12 Feb 2009 13:49:30 +0100 Subject: x86, mce, cmci: export MAX_NR_BANKS Impact: Cleanup (code movement) Move MAX_NR_BANKS into mce.h because it's needed there for followup patches. Signed-off-by: Andi Kleen Signed-off-by: H. Peter Anvin --- arch/x86/include/asm/mce.h | 6 ++++++ 1 file changed, 6 insertions(+) (limited to 'arch/x86/include') diff --git a/arch/x86/include/asm/mce.h b/arch/x86/include/asm/mce.h index 225cdb5d2bfc..39136c497c5e 100644 --- a/arch/x86/include/asm/mce.h +++ b/arch/x86/include/asm/mce.h @@ -95,6 +95,12 @@ void mce_log(struct mce *m); DECLARE_PER_CPU(struct sys_device, device_mce); extern void (*threshold_cpu_callback)(unsigned long action, unsigned int cpu); +/* + * To support more than 128 would need to escape the predefined + * Linux defined extended banks first. + */ +#define MAX_NR_BANKS (MCE_EXTENDED_BANK - 1) + #ifdef CONFIG_X86_MCE_INTEL void mce_intel_feature_init(struct cpuinfo_x86 *c); #else -- cgit v1.2.2 From b276268631af3a1b0df871e10d19d492f0513d4b Mon Sep 17 00:00:00 2001 From: Andi Kleen Date: Thu, 12 Feb 2009 13:49:31 +0100 Subject: x86, mce, cmci: factor out threshold interrupt handler Impact: cleanup; preparation for feature The mce_amd_64 code has an own private MC threshold vector with an own interrupt handler. Since Intel needs a similar handler it makes sense to share the vector because both can not be active at the same time. I factored the common APIC handler code into a separate file which can be used by both the Intel or AMD MC code. This is needed for the next patch which adds an Intel specific CMCI handler. This patch should be a nop for AMD, it just moves some code around. Signed-off-by: Andi Kleen Signed-off-by: H. Peter Anvin --- arch/x86/include/asm/mce.h | 2 ++ 1 file changed, 2 insertions(+) (limited to 'arch/x86/include') diff --git a/arch/x86/include/asm/mce.h b/arch/x86/include/asm/mce.h index 39136c497c5e..125cd8714622 100644 --- a/arch/x86/include/asm/mce.h +++ b/arch/x86/include/asm/mce.h @@ -135,5 +135,7 @@ extern void mcheck_init(struct cpuinfo_x86 *c); #define mcheck_init(c) do { } while (0) #endif +extern void (*mce_threshold_vector)(void); + #endif /* __KERNEL__ */ #endif /* _ASM_X86_MCE_H */ -- cgit v1.2.2 From ee031c31d6381d004bfd386c2e45821211507499 Mon Sep 17 00:00:00 2001 From: Andi Kleen Date: Thu, 12 Feb 2009 13:49:34 +0100 Subject: x86, mce, cmci: use polled banks bitmap in machine check poller Define a per cpu bitmap that contains the banks polled by the machine check poller. This is needed for the CMCI code in the next patches to be able to disable polling on specific banks. The bank by default contains all banks, so there is no behaviour change. Only future code will remove some banks from the polling set. Signed-off-by: Andi Kleen Signed-off-by: H. Peter Anvin --- arch/x86/include/asm/mce.h | 5 ++++- 1 file changed, 4 insertions(+), 1 deletion(-) (limited to 'arch/x86/include') diff --git a/arch/x86/include/asm/mce.h b/arch/x86/include/asm/mce.h index 125cd8714622..9b9523699dbc 100644 --- a/arch/x86/include/asm/mce.h +++ b/arch/x86/include/asm/mce.h @@ -119,11 +119,14 @@ extern atomic_t mce_entry; extern void do_machine_check(struct pt_regs *, long); +typedef DECLARE_BITMAP(mce_banks_t, MAX_NR_BANKS); +DECLARE_PER_CPU(mce_banks_t, mce_poll_banks); + enum mcp_flags { MCP_TIMESTAMP = (1 << 0), /* log time stamp */ MCP_UC = (1 << 1), /* log uncorrected errors */ }; -extern void machine_check_poll(enum mcp_flags flags); +extern void machine_check_poll(enum mcp_flags flags, mce_banks_t *b); extern int mce_notify_user(void); -- cgit v1.2.2 From 03195c6b40f2b4db92545921daa7c3a19b4e4c32 Mon Sep 17 00:00:00 2001 From: Andi Kleen Date: Thu, 12 Feb 2009 13:49:35 +0100 Subject: x86, mce, cmci: define MSR names and fields for new CMCI registers Impact: New register definitions only CMCI means support for raising an interrupt on a corrected machine check event instead of having to poll for it. It's a new feature in Intel Nehalem CPUs available on some machine check banks. For details see the IA32 SDM Vol3a 14.5 Define the registers for it as a preparation for further patches. Signed-off-by: Andi Kleen Signed-off-by: H. Peter Anvin --- arch/x86/include/asm/apicdef.h | 1 + arch/x86/include/asm/mce.h | 2 ++ arch/x86/include/asm/msr-index.h | 5 +++++ 3 files changed, 8 insertions(+) (limited to 'arch/x86/include') diff --git a/arch/x86/include/asm/apicdef.h b/arch/x86/include/asm/apicdef.h index 63134e31e8b9..bc9514fb3b13 100644 --- a/arch/x86/include/asm/apicdef.h +++ b/arch/x86/include/asm/apicdef.h @@ -53,6 +53,7 @@ #define APIC_ESR_SENDILL 0x00020 #define APIC_ESR_RECVILL 0x00040 #define APIC_ESR_ILLREGA 0x00080 +#define APIC_LVTCMCI 0x2f0 #define APIC_ICR 0x300 #define APIC_DEST_SELF 0x40000 #define APIC_DEST_ALLINC 0x80000 diff --git a/arch/x86/include/asm/mce.h b/arch/x86/include/asm/mce.h index 9b9523699dbc..6fc5e07eca4f 100644 --- a/arch/x86/include/asm/mce.h +++ b/arch/x86/include/asm/mce.h @@ -11,6 +11,8 @@ */ #define MCG_CTL_P (1UL<<8) /* MCG_CAP register available */ +#define MCG_EXT_P (1ULL<<9) /* Extended registers available */ +#define MCG_CMCI_P (1ULL<<10) /* CMCI supported */ #define MCG_STATUS_RIPV (1UL<<0) /* restart ip valid */ #define MCG_STATUS_EIPV (1UL<<1) /* ip points to correct instruction */ diff --git a/arch/x86/include/asm/msr-index.h b/arch/x86/include/asm/msr-index.h index 358acc59ae04..2dbd2314139e 100644 --- a/arch/x86/include/asm/msr-index.h +++ b/arch/x86/include/asm/msr-index.h @@ -77,6 +77,11 @@ #define MSR_IA32_MC0_ADDR 0x00000402 #define MSR_IA32_MC0_MISC 0x00000403 +/* These are consecutive and not in the normal 4er MCE bank block */ +#define MSR_IA32_MC0_CTL2 0x00000280 +#define CMCI_EN (1ULL << 30) +#define CMCI_THRESHOLD_MASK 0xffffULL + #define MSR_P6_PERFCTR0 0x000000c1 #define MSR_P6_PERFCTR1 0x000000c2 #define MSR_P6_EVNTSEL0 0x00000186 -- cgit v1.2.2 From 88ccbedd9ca85d1aca6a6f99df48dce87b7c02d4 Mon Sep 17 00:00:00 2001 From: Andi Kleen Date: Thu, 12 Feb 2009 13:49:36 +0100 Subject: x86, mce, cmci: add CMCI support Impact: Major new feature Intel CMCI (Corrected Machine Check Interrupt) is a new feature on Nehalem CPUs. It allows the CPU to trigger interrupts on corrected events, which allows faster reaction to them instead of with the traditional polling timer. Also use CMCI to discover shared banks. Machine check banks can be shared by CPU threads or even cores. Using the CMCI enable bit it is possible to detect the fact that another CPU already saw a specific bank. Use this to assign shared banks only to one CPU to avoid reporting duplicated events. On CPU hot unplug bank sharing is re discovered. This is done using a thread that cycles through all the CPUs. To avoid races between the poller and CMCI we only poll for banks that are not CMCI capable and only check CMCI owned banks on a interrupt. The shared banks ownership information is currently only used for CMCI interrupts, not polled banks. The sharing discovery code follows the algorithm recommended in the IA32 SDM Vol3a 14.5.2.1 The CMCI interrupt handler just calls the machine check poller to pick up the machine check event that caused the interrupt. I decided not to implement a separate threshold event like the AMD version has, because the threshold is always one currently and adding another event didn't seem to add any value. Some code inspired by Yunhong Jiang's Xen implementation, which was in term inspired by a earlier CMCI implementation by me. Signed-off-by: Andi Kleen Signed-off-by: H. Peter Anvin --- arch/x86/include/asm/mce.h | 10 ++++++++++ 1 file changed, 10 insertions(+) (limited to 'arch/x86/include') diff --git a/arch/x86/include/asm/mce.h b/arch/x86/include/asm/mce.h index 6fc5e07eca4f..563933e06a35 100644 --- a/arch/x86/include/asm/mce.h +++ b/arch/x86/include/asm/mce.h @@ -105,8 +105,16 @@ extern void (*threshold_cpu_callback)(unsigned long action, unsigned int cpu); #ifdef CONFIG_X86_MCE_INTEL void mce_intel_feature_init(struct cpuinfo_x86 *c); +void cmci_clear(void); +void cmci_reenable(void); +void cmci_rediscover(int dying); +void cmci_recheck(void); #else static inline void mce_intel_feature_init(struct cpuinfo_x86 *c) { } +static inline void cmci_clear(void) {} +static inline void cmci_reenable(void) {} +static inline void cmci_rediscover(int dying) {} +static inline void cmci_recheck(void) {} #endif #ifdef CONFIG_X86_MCE_AMD @@ -115,6 +123,8 @@ void mce_amd_feature_init(struct cpuinfo_x86 *c); static inline void mce_amd_feature_init(struct cpuinfo_x86 *c) { } #endif +extern int mce_available(struct cpuinfo_x86 *c); + void mce_log_therm_throt_event(__u64 status); extern atomic_t mce_entry; -- cgit v1.2.2