[PATCH 2/4] x86/mce/amd: Introduce deferred error interrupt handler

From: Aravind Gopalakrishnan
Date: Thu Apr 30 2015 - 15:53:27 EST

Changes introduced in the patch-
- Assign vector number 0xf4 for Deferred errors
- Declare deferred_interrupt, allocate gate and bind it
to DEFERRED_APIC_VECTOR.
- Declare smp_deferred_interrupt to be used as the
entry point for the interrupt in mce_amd.c
- Define trace_deferred_interrupt for tracing
- Enable deferred error interrupt selectively upon detection
of 'succor' bitfield
- Setup amd_deferred_error_interrupt() to handle the interrupt
and assign it to def_int_vector if feature is present in HW.
Else, let default handler deal with it.
- Provide Deferred error interrupt stats on
/proc/interrupts by incrementing irq_deferred_count

Signed-off-by: Aravind Gopalakrishnan <Aravind.Gopalakrishnan@xxxxxxx>
---
arch/x86/include/asm/entry_arch.h | 3 +
arch/x86/include/asm/hardirq.h | 3 +
arch/x86/include/asm/hw_irq.h | 2 +
arch/x86/include/asm/irq_vectors.h | 1 +
arch/x86/include/asm/mce.h | 3 +
arch/x86/include/asm/trace/irq_vectors.h | 6 ++
arch/x86/include/asm/traps.h | 3 +-
arch/x86/kernel/cpu/mcheck/mce_amd.c | 101 +++++++++++++++++++++++++++++++
arch/x86/kernel/entry_64.S | 5 ++
arch/x86/kernel/irq.c | 6 ++
arch/x86/kernel/irqinit.c | 4 ++
arch/x86/kernel/traps.c | 4 ++
12 files changed, 140 insertions(+), 1 deletion(-)

diff --git a/arch/x86/include/asm/entry_arch.h b/arch/x86/include/asm/entry_arch.h
index dc5fa66..f7b957b 100644
--- a/arch/x86/include/asm/entry_arch.h
+++ b/arch/x86/include/asm/entry_arch.h
@@ -50,4 +50,7 @@ BUILD_INTERRUPT(thermal_interrupt,THERMAL_APIC_VECTOR)
BUILD_INTERRUPT(threshold_interrupt,THRESHOLD_APIC_VECTOR)
#endif

+#ifdef CONFIG_X86_MCE_AMD
+BUILD_INTERRUPT(deferred_interrupt, DEFERRED_APIC_VECTOR)
+#endif
#endif
diff --git a/arch/x86/include/asm/hardirq.h b/arch/x86/include/asm/hardirq.h
index 0f5fb6b..448451c 100644
--- a/arch/x86/include/asm/hardirq.h
+++ b/arch/x86/include/asm/hardirq.h
@@ -33,6 +33,9 @@ typedef struct {
#ifdef CONFIG_X86_MCE_THRESHOLD
unsigned int irq_threshold_count;
#endif
+#ifdef CONFIG_X86_MCE_AMD
+ unsigned int irq_deferred_count;
+#endif
#if IS_ENABLED(CONFIG_HYPERV) || defined(CONFIG_XEN)
unsigned int irq_hv_callback_count;
#endif
diff --git a/arch/x86/include/asm/hw_irq.h b/arch/x86/include/asm/hw_irq.h
index e9571dd..7cf2670 100644
--- a/arch/x86/include/asm/hw_irq.h
+++ b/arch/x86/include/asm/hw_irq.h
@@ -73,6 +73,7 @@ extern asmlinkage void invalidate_interrupt31(void);
extern asmlinkage void irq_move_cleanup_interrupt(void);
extern asmlinkage void reboot_interrupt(void);
extern asmlinkage void threshold_interrupt(void);
+extern asmlinkage void deferred_interrupt(void);

extern asmlinkage void call_function_interrupt(void);
extern asmlinkage void call_function_single_interrupt(void);
@@ -87,6 +88,7 @@ extern void trace_spurious_interrupt(void);
extern void trace_thermal_interrupt(void);
extern void trace_reschedule_interrupt(void);
extern void trace_threshold_interrupt(void);
+extern void trace_deferred_interrupt(void);
extern void trace_call_function_interrupt(void);
extern void trace_call_function_single_interrupt(void);
#define trace_irq_move_cleanup_interrupt irq_move_cleanup_interrupt
diff --git a/arch/x86/include/asm/irq_vectors.h b/arch/x86/include/asm/irq_vectors.h
index 666c89e..cee723f 100644
--- a/arch/x86/include/asm/irq_vectors.h
+++ b/arch/x86/include/asm/irq_vectors.h
@@ -113,6 +113,7 @@
#define IRQ_WORK_VECTOR 0xf6

#define UV_BAU_MESSAGE 0xf5
+#define DEFERRED_APIC_VECTOR 0xf4

/* Vector on which hypervisor callbacks will be delivered */
#define HYPERVISOR_CALLBACK_VECTOR 0xf3
diff --git a/arch/x86/include/asm/mce.h b/arch/x86/include/asm/mce.h
index dfcb664..b21b887 100644
--- a/arch/x86/include/asm/mce.h
+++ b/arch/x86/include/asm/mce.h
@@ -224,6 +224,9 @@ void do_machine_check(struct pt_regs *, long);
extern void (*mce_threshold_vector)(void);
extern void (*threshold_cpu_callback)(unsigned long action, unsigned int cpu);

+/* Deferred error interrupt handler */
+extern void (*deferred_int_vector)(void);
+
/*
* Thermal handler
*/
diff --git a/arch/x86/include/asm/trace/irq_vectors.h b/arch/x86/include/asm/trace/irq_vectors.h
index 4cab890..3c1f0a7 100644
--- a/arch/x86/include/asm/trace/irq_vectors.h
+++ b/arch/x86/include/asm/trace/irq_vectors.h
@@ -101,6 +101,12 @@ DEFINE_IRQ_VECTOR_EVENT(call_function_single);
DEFINE_IRQ_VECTOR_EVENT(threshold_apic);

/*
+ * deferred_apic - called when entering/exiting a deferred apic interrupt
+ * vector handler
+ */
+DEFINE_IRQ_VECTOR_EVENT(deferred_apic);
+
+/*
* thermal_apic - called when entering/exiting a thermal apic interrupt
* vector handler
*/
diff --git a/arch/x86/include/asm/traps.h b/arch/x86/include/asm/traps.h
index 4e49d7d..ef937b7 100644
--- a/arch/x86/include/asm/traps.h
+++ b/arch/x86/include/asm/traps.h
@@ -108,7 +108,8 @@ extern int panic_on_unrecovered_nmi;
void math_emulate(struct math_emu_info *);
#ifndef CONFIG_X86_32
asmlinkage void smp_thermal_interrupt(void);
-asmlinkage void mce_threshold_interrupt(void);
+asmlinkage void smp_threshold_interrupt(void);
+asmlinkage void smp_deferred_interrupt(void);
#endif

extern enum ctx_state ist_enter(struct pt_regs *regs);
diff --git a/arch/x86/kernel/cpu/mcheck/mce_amd.c b/arch/x86/kernel/cpu/mcheck/mce_amd.c
index 55ad9b3..ce82f0b 100644
--- a/arch/x86/kernel/cpu/mcheck/mce_amd.c
+++ b/arch/x86/kernel/cpu/mcheck/mce_amd.c
@@ -12,6 +12,8 @@
* - added support for AMD Family 0x10 processors
* May 2012
* - major scrubbing
+ * April 2015
+ * - add support for deferred error interrupts
*
* All MC4_MISCi registers are shared between multi-cores
*/
@@ -32,6 +34,7 @@
#include <asm/idle.h>
#include <asm/mce.h>
#include <asm/msr.h>
+#include <asm/trace/irq_vectors.h>

#define NR_BLOCKS 9
#define THRESHOLD_MAX 0xFFF
@@ -47,6 +50,13 @@
#define MASK_BLKPTR_LO 0xFF000000
#define MCG_XBLK_ADDR 0xC0000400

+/* Deferred error settings */
+#define MSR_CU_DEF_ERR 0xC0000410
+#define MASK_DEF_LVTOFF 0x000000F0
+#define MASK_DEF_INT_TYPE 0x00000006
+#define DEF_LVT_OFF 0x2
+#define DEF_INT_TYPE_APIC 0x2
+
static const char * const th_names[] = {
"load_store",
"insn_fetch",
@@ -60,6 +70,15 @@ static DEFINE_PER_CPU(struct threshold_bank **, threshold_banks);
static DEFINE_PER_CPU(unsigned char, bank_map); /* see which banks are on */

static void amd_threshold_interrupt(void);
+static void amd_deferred_error_interrupt(void);
+
+/* Setup default deferred error interrupt handler */
+static void default_deferred_interrupt(void)
+{
+ pr_err("Unexpected deferred interrupt at vector %x\n",
+ DEFERRED_APIC_VECTOR);
+}
+void (*def_int_vector)(void) = default_deferred_interrupt;

/*
* CPU Initialization
@@ -205,6 +224,62 @@ static int setup_APIC_mce(int reserved, int new)
return reserved;
}

+static int setup_APIC_deferred_error(int reserved, int new)
+{
+ if (reserved < 0 && !setup_APIC_eilvt(new, DEFERRED_APIC_VECTOR,
+ APIC_EILVT_MSG_FIX, 0))
+ return new;
+
+ return reserved;
+}
+
+static void deferred_error_interrupt_enable(struct cpuinfo_x86 *c)
+{
+ u32 low = 0, high = 0;
+ int def_offset = -1, def_new;
+
+ if (rdmsr_safe(MSR_CU_DEF_ERR, &low, &high))
+ return;
+
+ def_new = (low & MASK_DEF_LVTOFF) >> 4;
+ if (c->x86 == 0x15 && c->x86_model == 0x60 &&
+ !(low & MASK_DEF_LVTOFF)) {
+ def_new = DEF_LVT_OFF;
+ low = (low & ~MASK_DEF_LVTOFF) | (DEF_LVT_OFF << 4);
+ }
+
+ def_offset = setup_APIC_deferred_error(def_offset, def_new);
+
+ if ((def_offset == def_new) &&
+ (def_int_vector != amd_deferred_error_interrupt))
+ def_int_vector = amd_deferred_error_interrupt;
+
+ low = (low & ~MASK_DEF_INT_TYPE) | DEF_INT_TYPE_APIC;
+ wrmsr(MSR_CU_DEF_ERR, low, high);
+}
+
+static inline void __smp_deferred_interrupt(void)
+{
+ inc_irq_stat(irq_deferred_count);
+ def_int_vector();
+}
+
+asmlinkage __visible void smp_deferred_interrupt(void)
+{
+ entering_irq();
+ __smp_deferred_interrupt();
+ exiting_ack_irq();
+}
+
+asmlinkage __visible void smp_trace_deferred_interrupt(void)
+{
+ entering_irq();
+ trace_deferred_apic_entry(DEFERRED_APIC_VECTOR);
+ __smp_deferred_interrupt();
+ trace_deferred_apic_exit(DEFERRED_APIC_VECTOR);
+ exiting_ack_irq();
+}
+
/* cpu init entry point, called from mce.c with preempt off */
void mce_amd_feature_init(struct cpuinfo_x86 *c)
{
@@ -262,6 +337,32 @@ init:
mce_threshold_block_init(&b, offset);
}
}
+
+ if (mce_flags.succor)
+ deferred_error_interrupt_enable(c);
+}
+
+/* Apic interrupt handler for deferred errors */
+static void amd_deferred_error_interrupt(void)
+{
+ u64 status;
+ unsigned int bank;
+ struct mce m;
+
+ for (bank = 0; bank < mca_cfg.banks; ++bank) {
+ rdmsrl(MSR_IA32_MCx_STATUS(bank), status);
+
+ if (!(status & MCI_STATUS_VAL) ||
+ !(status & MCI_STATUS_DEFERRED))
+ continue;
+
+ mce_setup(&m);
+ m.bank = bank;
+ m.status = status;
+ mce_log(&m);
+ wrmsrl(MSR_IA32_MCx_STATUS(bank), 0);
+ break;
+ }
}

/*
diff --git a/arch/x86/kernel/entry_64.S b/arch/x86/kernel/entry_64.S
index e952f6b..820965c 100644
--- a/arch/x86/kernel/entry_64.S
+++ b/arch/x86/kernel/entry_64.S
@@ -914,6 +914,11 @@ apicinterrupt THRESHOLD_APIC_VECTOR \
threshold_interrupt smp_threshold_interrupt
#endif

+#ifdef CONFIG_X86_MCE_AMD
+apicinterrupt DEFERRED_APIC_VECTOR \
+ deferred_interrupt smp_deferred_interrupt
+#endif
+
#ifdef CONFIG_X86_THERMAL_VECTOR
apicinterrupt THERMAL_APIC_VECTOR \
thermal_interrupt smp_thermal_interrupt
diff --git a/arch/x86/kernel/irq.c b/arch/x86/kernel/irq.c
index e5952c2..406f204 100644
--- a/arch/x86/kernel/irq.c
+++ b/arch/x86/kernel/irq.c
@@ -116,6 +116,12 @@ int arch_show_interrupts(struct seq_file *p, int prec)
seq_printf(p, "%10u ", irq_stats(j)->irq_threshold_count);
seq_puts(p, " Threshold APIC interrupts\n");
#endif
+#ifdef CONFIG_X86_MCE_AMD
+ seq_printf(p, "%*s: ", prec, "DEF");
+ for_each_online_cpu(j)
+ seq_printf(p, "%10u ", irq_stats(j)->irq_deferred_count);
+ seq_puts(p, " Deferred APIC interrupts\n");
+#endif
#ifdef CONFIG_X86_MCE
seq_printf(p, "%*s: ", prec, "MCE");
for_each_online_cpu(j)
diff --git a/arch/x86/kernel/irqinit.c b/arch/x86/kernel/irqinit.c
index cd10a64..e0ffd29 100644
--- a/arch/x86/kernel/irqinit.c
+++ b/arch/x86/kernel/irqinit.c
@@ -135,6 +135,10 @@ static void __init apic_intr_init(void)
alloc_intr_gate(THRESHOLD_APIC_VECTOR, threshold_interrupt);
#endif

+#ifdef CONFIG_X86_MCE_AMD
+ alloc_intr_gate(DEFERRED_APIC_VECTOR, deferred_interrupt);
+#endif
+
#ifdef CONFIG_X86_LOCAL_APIC
/* self generated IPI for local APIC timer */
alloc_intr_gate(LOCAL_TIMER_VECTOR, apic_timer_interrupt);
diff --git a/arch/x86/kernel/traps.c b/arch/x86/kernel/traps.c
index 324ab52..dbfe07c2 100644
--- a/arch/x86/kernel/traps.c
+++ b/arch/x86/kernel/traps.c
@@ -827,6 +827,10 @@ asmlinkage __visible void __attribute__((weak)) smp_threshold_interrupt(void)
{
}

+asmlinkage __visible void __attribute__((weak)) smp_deferred_interrupt(void)
+{
+}
+
/*
* 'math_state_restore()' saves the current math information in the
* old math state array, and gets the new ones from the current task
--
1.9.1

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