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Date: Mon, 11 Nov 2013 19:59:51 +0100
From: Ingo Molnar <mingo@...nel.org>
To: Linus Torvalds <torvalds@...ux-foundation.org>
Cc: linux-kernel@...r.kernel.org, "H. Peter Anvin" <hpa@...or.com>,
Thomas Gleixner <tglx@...utronix.de>,
Andrew Morton <akpm@...ux-foundation.org>,
Jason Wessel <jason.wessel@...driver.com>
Subject: [GIT PULL] x86/uv changes for v3.13, UV KDB support
Linus,
Please pull the latest x86-uv-for-linus git tree from:
git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip.git x86-uv-for-linus
# HEAD: b5dfcb09debc38582c3cb72a3c1a88b919b07f2d Revert "x86/UV: Add uvtrace support"
Various SGI UV debuggability improvements, amongst them KDB support, with
related core KDB enabling patches changing kernel/debug/kdb/.
out-of-topic modifications in x86-uv-for-linus:
-------------------------------------------------
include/linux/kdb.h # 8daaa5f: kdb: Add support for external NMI
include/linux/kgdb.h # 8daaa5f: kdb: Add support for external NMI
kernel/debug/debug_core.c # 8daaa5f: kdb: Add support for external NMI
kernel/debug/debug_core.h # 8daaa5f: kdb: Add support for external NMI
kernel/debug/kdb/kdb_debugger.c # 8daaa5f: kdb: Add support for external NMI
kernel/debug/kdb/kdb_main.c # 8daaa5f: kdb: Add support for external NMI
Thanks,
Ingo
------------------>
Ingo Molnar (2):
x86/UV: Check for alloc_cpumask_var() failures properly in uv_nmi_setup()
Revert "x86/UV: Add uvtrace support"
Mike Travis (7):
x86/UV: Move NMI support
x86/UV: Update UV support for external NMI signals
x86/UV: Add summary of cpu activity to UV NMI handler
x86/UV: Add kdump to UV NMI handler
x86/UV: Add uvtrace support
kdb: Add support for external NMI handler to call KGDB/KDB
x86/UV: Add call to KGDB/KDB from NMI handler
arch/x86/include/asm/uv/uv.h | 2 +
arch/x86/include/asm/uv/uv_hub.h | 57 ++-
arch/x86/include/asm/uv/uv_mmrs.h | 31 ++
arch/x86/kernel/apic/x2apic_uv_x.c | 70 +---
arch/x86/platform/uv/Makefile | 2 +-
arch/x86/platform/uv/uv_nmi.c | 700 +++++++++++++++++++++++++++++++++++++
include/linux/kdb.h | 1 +
include/linux/kgdb.h | 1 +
kernel/debug/debug_core.c | 32 +-
kernel/debug/debug_core.h | 3 +
kernel/debug/kdb/kdb_debugger.c | 5 +-
kernel/debug/kdb/kdb_main.c | 3 +
12 files changed, 832 insertions(+), 75 deletions(-)
create mode 100644 arch/x86/platform/uv/uv_nmi.c
diff --git a/arch/x86/include/asm/uv/uv.h b/arch/x86/include/asm/uv/uv.h
index 062921e..6b964a0 100644
--- a/arch/x86/include/asm/uv/uv.h
+++ b/arch/x86/include/asm/uv/uv.h
@@ -12,6 +12,7 @@ extern enum uv_system_type get_uv_system_type(void);
extern int is_uv_system(void);
extern void uv_cpu_init(void);
extern void uv_nmi_init(void);
+extern void uv_register_nmi_notifier(void);
extern void uv_system_init(void);
extern const struct cpumask *uv_flush_tlb_others(const struct cpumask *cpumask,
struct mm_struct *mm,
@@ -25,6 +26,7 @@ static inline enum uv_system_type get_uv_system_type(void) { return UV_NONE; }
static inline int is_uv_system(void) { return 0; }
static inline void uv_cpu_init(void) { }
static inline void uv_system_init(void) { }
+static inline void uv_register_nmi_notifier(void) { }
static inline const struct cpumask *
uv_flush_tlb_others(const struct cpumask *cpumask, struct mm_struct *mm,
unsigned long start, unsigned long end, unsigned int cpu)
diff --git a/arch/x86/include/asm/uv/uv_hub.h b/arch/x86/include/asm/uv/uv_hub.h
index 2c32df9..a30836c 100644
--- a/arch/x86/include/asm/uv/uv_hub.h
+++ b/arch/x86/include/asm/uv/uv_hub.h
@@ -502,8 +502,8 @@ struct uv_blade_info {
unsigned short nr_online_cpus;
unsigned short pnode;
short memory_nid;
- spinlock_t nmi_lock;
- unsigned long nmi_count;
+ spinlock_t nmi_lock; /* obsolete, see uv_hub_nmi */
+ unsigned long nmi_count; /* obsolete, see uv_hub_nmi */
};
extern struct uv_blade_info *uv_blade_info;
extern short *uv_node_to_blade;
@@ -576,6 +576,59 @@ static inline int uv_num_possible_blades(void)
return uv_possible_blades;
}
+/* Per Hub NMI support */
+extern void uv_nmi_setup(void);
+
+/* BMC sets a bit this MMR non-zero before sending an NMI */
+#define UVH_NMI_MMR UVH_SCRATCH5
+#define UVH_NMI_MMR_CLEAR UVH_SCRATCH5_ALIAS
+#define UVH_NMI_MMR_SHIFT 63
+#define UVH_NMI_MMR_TYPE "SCRATCH5"
+
+/* Newer SMM NMI handler, not present in all systems */
+#define UVH_NMI_MMRX UVH_EVENT_OCCURRED0
+#define UVH_NMI_MMRX_CLEAR UVH_EVENT_OCCURRED0_ALIAS
+#define UVH_NMI_MMRX_SHIFT (is_uv1_hub() ? \
+ UV1H_EVENT_OCCURRED0_EXTIO_INT0_SHFT :\
+ UVXH_EVENT_OCCURRED0_EXTIO_INT0_SHFT)
+#define UVH_NMI_MMRX_TYPE "EXTIO_INT0"
+
+/* Non-zero indicates newer SMM NMI handler present */
+#define UVH_NMI_MMRX_SUPPORTED UVH_EXTIO_INT0_BROADCAST
+
+/* Indicates to BIOS that we want to use the newer SMM NMI handler */
+#define UVH_NMI_MMRX_REQ UVH_SCRATCH5_ALIAS_2
+#define UVH_NMI_MMRX_REQ_SHIFT 62
+
+struct uv_hub_nmi_s {
+ raw_spinlock_t nmi_lock;
+ atomic_t in_nmi; /* flag this node in UV NMI IRQ */
+ atomic_t cpu_owner; /* last locker of this struct */
+ atomic_t read_mmr_count; /* count of MMR reads */
+ atomic_t nmi_count; /* count of true UV NMIs */
+ unsigned long nmi_value; /* last value read from NMI MMR */
+};
+
+struct uv_cpu_nmi_s {
+ struct uv_hub_nmi_s *hub;
+ atomic_t state;
+ atomic_t pinging;
+ int queries;
+ int pings;
+};
+
+DECLARE_PER_CPU(struct uv_cpu_nmi_s, __uv_cpu_nmi);
+#define uv_cpu_nmi (__get_cpu_var(__uv_cpu_nmi))
+#define uv_hub_nmi (uv_cpu_nmi.hub)
+#define uv_cpu_nmi_per(cpu) (per_cpu(__uv_cpu_nmi, cpu))
+#define uv_hub_nmi_per(cpu) (uv_cpu_nmi_per(cpu).hub)
+
+/* uv_cpu_nmi_states */
+#define UV_NMI_STATE_OUT 0
+#define UV_NMI_STATE_IN 1
+#define UV_NMI_STATE_DUMP 2
+#define UV_NMI_STATE_DUMP_DONE 3
+
/* Update SCIR state */
static inline void uv_set_scir_bits(unsigned char value)
{
diff --git a/arch/x86/include/asm/uv/uv_mmrs.h b/arch/x86/include/asm/uv/uv_mmrs.h
index bd5f80e..e42249b 100644
--- a/arch/x86/include/asm/uv/uv_mmrs.h
+++ b/arch/x86/include/asm/uv/uv_mmrs.h
@@ -461,6 +461,23 @@ union uvh_event_occurred0_u {
/* ========================================================================= */
+/* UVH_EXTIO_INT0_BROADCAST */
+/* ========================================================================= */
+#define UVH_EXTIO_INT0_BROADCAST 0x61448UL
+#define UVH_EXTIO_INT0_BROADCAST_32 0x3f0
+
+#define UVH_EXTIO_INT0_BROADCAST_ENABLE_SHFT 0
+#define UVH_EXTIO_INT0_BROADCAST_ENABLE_MASK 0x0000000000000001UL
+
+union uvh_extio_int0_broadcast_u {
+ unsigned long v;
+ struct uvh_extio_int0_broadcast_s {
+ unsigned long enable:1; /* RW */
+ unsigned long rsvd_1_63:63;
+ } s;
+};
+
+/* ========================================================================= */
/* UVH_GR0_TLB_INT0_CONFIG */
/* ========================================================================= */
#define UVH_GR0_TLB_INT0_CONFIG 0x61b00UL
@@ -2606,6 +2623,20 @@ union uvh_scratch5_u {
};
/* ========================================================================= */
+/* UVH_SCRATCH5_ALIAS */
+/* ========================================================================= */
+#define UVH_SCRATCH5_ALIAS 0x2d0208UL
+#define UVH_SCRATCH5_ALIAS_32 0x780
+
+
+/* ========================================================================= */
+/* UVH_SCRATCH5_ALIAS_2 */
+/* ========================================================================= */
+#define UVH_SCRATCH5_ALIAS_2 0x2d0210UL
+#define UVH_SCRATCH5_ALIAS_2_32 0x788
+
+
+/* ========================================================================= */
/* UVXH_EVENT_OCCURRED2 */
/* ========================================================================= */
#define UVXH_EVENT_OCCURRED2 0x70100UL
diff --git a/arch/x86/kernel/apic/x2apic_uv_x.c b/arch/x86/kernel/apic/x2apic_uv_x.c
index 1191ac1..0a5a4b8 100644
--- a/arch/x86/kernel/apic/x2apic_uv_x.c
+++ b/arch/x86/kernel/apic/x2apic_uv_x.c
@@ -39,12 +39,6 @@
#include <asm/x86_init.h>
#include <asm/nmi.h>
-/* BMC sets a bit this MMR non-zero before sending an NMI */
-#define UVH_NMI_MMR UVH_SCRATCH5
-#define UVH_NMI_MMR_CLEAR (UVH_NMI_MMR + 8)
-#define UV_NMI_PENDING_MASK (1UL << 63)
-DEFINE_PER_CPU(unsigned long, cpu_last_nmi_count);
-
DEFINE_PER_CPU(int, x2apic_extra_bits);
#define PR_DEVEL(fmt, args...) pr_devel("%s: " fmt, __func__, args)
@@ -58,7 +52,6 @@ int uv_min_hub_revision_id;
EXPORT_SYMBOL_GPL(uv_min_hub_revision_id);
unsigned int uv_apicid_hibits;
EXPORT_SYMBOL_GPL(uv_apicid_hibits);
-static DEFINE_SPINLOCK(uv_nmi_lock);
static struct apic apic_x2apic_uv_x;
@@ -847,68 +840,6 @@ void uv_cpu_init(void)
set_x2apic_extra_bits(uv_hub_info->pnode);
}
-/*
- * When NMI is received, print a stack trace.
- */
-int uv_handle_nmi(unsigned int reason, struct pt_regs *regs)
-{
- unsigned long real_uv_nmi;
- int bid;
-
- /*
- * Each blade has an MMR that indicates when an NMI has been sent
- * to cpus on the blade. If an NMI is detected, atomically
- * clear the MMR and update a per-blade NMI count used to
- * cause each cpu on the blade to notice a new NMI.
- */
- bid = uv_numa_blade_id();
- real_uv_nmi = (uv_read_local_mmr(UVH_NMI_MMR) & UV_NMI_PENDING_MASK);
-
- if (unlikely(real_uv_nmi)) {
- spin_lock(&uv_blade_info[bid].nmi_lock);
- real_uv_nmi = (uv_read_local_mmr(UVH_NMI_MMR) & UV_NMI_PENDING_MASK);
- if (real_uv_nmi) {
- uv_blade_info[bid].nmi_count++;
- uv_write_local_mmr(UVH_NMI_MMR_CLEAR, UV_NMI_PENDING_MASK);
- }
- spin_unlock(&uv_blade_info[bid].nmi_lock);
- }
-
- if (likely(__get_cpu_var(cpu_last_nmi_count) == uv_blade_info[bid].nmi_count))
- return NMI_DONE;
-
- __get_cpu_var(cpu_last_nmi_count) = uv_blade_info[bid].nmi_count;
-
- /*
- * Use a lock so only one cpu prints at a time.
- * This prevents intermixed output.
- */
- spin_lock(&uv_nmi_lock);
- pr_info("UV NMI stack dump cpu %u:\n", smp_processor_id());
- dump_stack();
- spin_unlock(&uv_nmi_lock);
-
- return NMI_HANDLED;
-}
-
-void uv_register_nmi_notifier(void)
-{
- if (register_nmi_handler(NMI_UNKNOWN, uv_handle_nmi, 0, "uv"))
- printk(KERN_WARNING "UV NMI handler failed to register\n");
-}
-
-void uv_nmi_init(void)
-{
- unsigned int value;
-
- /*
- * Unmask NMI on all cpus
- */
- value = apic_read(APIC_LVT1) | APIC_DM_NMI;
- value &= ~APIC_LVT_MASKED;
- apic_write(APIC_LVT1, value);
-}
-
void __init uv_system_init(void)
{
union uvh_rh_gam_config_mmr_u m_n_config;
@@ -1046,6 +977,7 @@ void __init uv_system_init(void)
map_mmr_high(max_pnode);
map_mmioh_high(min_pnode, max_pnode);
+ uv_nmi_setup();
uv_cpu_init();
uv_scir_register_cpu_notifier();
uv_register_nmi_notifier();
diff --git a/arch/x86/platform/uv/Makefile b/arch/x86/platform/uv/Makefile
index 6c40995..52079be 100644
--- a/arch/x86/platform/uv/Makefile
+++ b/arch/x86/platform/uv/Makefile
@@ -1 +1 @@
-obj-$(CONFIG_X86_UV) += tlb_uv.o bios_uv.o uv_irq.o uv_sysfs.o uv_time.o
+obj-$(CONFIG_X86_UV) += tlb_uv.o bios_uv.o uv_irq.o uv_sysfs.o uv_time.o uv_nmi.o
diff --git a/arch/x86/platform/uv/uv_nmi.c b/arch/x86/platform/uv/uv_nmi.c
new file mode 100644
index 0000000..2e863ad
--- /dev/null
+++ b/arch/x86/platform/uv/uv_nmi.c
@@ -0,0 +1,700 @@
+/*
+ * SGI NMI support routines
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License as published by
+ * the Free Software Foundation; either version 2 of the License, or
+ * (at your option) any later version.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
+ * GNU General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with this program; if not, write to the Free Software
+ * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA
+ *
+ * Copyright (c) 2009-2013 Silicon Graphics, Inc. All Rights Reserved.
+ * Copyright (c) Mike Travis
+ */
+
+#include <linux/cpu.h>
+#include <linux/delay.h>
+#include <linux/kdb.h>
+#include <linux/kexec.h>
+#include <linux/kgdb.h>
+#include <linux/module.h>
+#include <linux/nmi.h>
+#include <linux/sched.h>
+#include <linux/slab.h>
+
+#include <asm/apic.h>
+#include <asm/current.h>
+#include <asm/kdebug.h>
+#include <asm/local64.h>
+#include <asm/nmi.h>
+#include <asm/traps.h>
+#include <asm/uv/uv.h>
+#include <asm/uv/uv_hub.h>
+#include <asm/uv/uv_mmrs.h>
+
+/*
+ * UV handler for NMI
+ *
+ * Handle system-wide NMI events generated by the global 'power nmi' command.
+ *
+ * Basic operation is to field the NMI interrupt on each cpu and wait
+ * until all cpus have arrived into the nmi handler. If some cpus do not
+ * make it into the handler, try and force them in with the IPI(NMI) signal.
+ *
+ * We also have to lessen UV Hub MMR accesses as much as possible as this
+ * disrupts the UV Hub's primary mission of directing NumaLink traffic and
+ * can cause system problems to occur.
+ *
+ * To do this we register our primary NMI notifier on the NMI_UNKNOWN
+ * chain. This reduces the number of false NMI calls when the perf
+ * tools are running which generate an enormous number of NMIs per
+ * second (~4M/s for 1024 cpu threads). Our secondary NMI handler is
+ * very short as it only checks that if it has been "pinged" with the
+ * IPI(NMI) signal as mentioned above, and does not read the UV Hub's MMR.
+ *
+ */
+
+static struct uv_hub_nmi_s **uv_hub_nmi_list;
+
+DEFINE_PER_CPU(struct uv_cpu_nmi_s, __uv_cpu_nmi);
+EXPORT_PER_CPU_SYMBOL_GPL(__uv_cpu_nmi);
+
+static unsigned long nmi_mmr;
+static unsigned long nmi_mmr_clear;
+static unsigned long nmi_mmr_pending;
+
+static atomic_t uv_in_nmi;
+static atomic_t uv_nmi_cpu = ATOMIC_INIT(-1);
+static atomic_t uv_nmi_cpus_in_nmi = ATOMIC_INIT(-1);
+static atomic_t uv_nmi_slave_continue;
+static atomic_t uv_nmi_kexec_failed;
+static cpumask_var_t uv_nmi_cpu_mask;
+
+/* Values for uv_nmi_slave_continue */
+#define SLAVE_CLEAR 0
+#define SLAVE_CONTINUE 1
+#define SLAVE_EXIT 2
+
+/*
+ * Default is all stack dumps go to the console and buffer.
+ * Lower level to send to log buffer only.
+ */
+static int uv_nmi_loglevel = 7;
+module_param_named(dump_loglevel, uv_nmi_loglevel, int, 0644);
+
+/*
+ * The following values show statistics on how perf events are affecting
+ * this system.
+ */
+static int param_get_local64(char *buffer, const struct kernel_param *kp)
+{
+ return sprintf(buffer, "%lu\n", local64_read((local64_t *)kp->arg));
+}
+
+static int param_set_local64(const char *val, const struct kernel_param *kp)
+{
+ /* clear on any write */
+ local64_set((local64_t *)kp->arg, 0);
+ return 0;
+}
+
+static struct kernel_param_ops param_ops_local64 = {
+ .get = param_get_local64,
+ .set = param_set_local64,
+};
+#define param_check_local64(name, p) __param_check(name, p, local64_t)
+
+static local64_t uv_nmi_count;
+module_param_named(nmi_count, uv_nmi_count, local64, 0644);
+
+static local64_t uv_nmi_misses;
+module_param_named(nmi_misses, uv_nmi_misses, local64, 0644);
+
+static local64_t uv_nmi_ping_count;
+module_param_named(ping_count, uv_nmi_ping_count, local64, 0644);
+
+static local64_t uv_nmi_ping_misses;
+module_param_named(ping_misses, uv_nmi_ping_misses, local64, 0644);
+
+/*
+ * Following values allow tuning for large systems under heavy loading
+ */
+static int uv_nmi_initial_delay = 100;
+module_param_named(initial_delay, uv_nmi_initial_delay, int, 0644);
+
+static int uv_nmi_slave_delay = 100;
+module_param_named(slave_delay, uv_nmi_slave_delay, int, 0644);
+
+static int uv_nmi_loop_delay = 100;
+module_param_named(loop_delay, uv_nmi_loop_delay, int, 0644);
+
+static int uv_nmi_trigger_delay = 10000;
+module_param_named(trigger_delay, uv_nmi_trigger_delay, int, 0644);
+
+static int uv_nmi_wait_count = 100;
+module_param_named(wait_count, uv_nmi_wait_count, int, 0644);
+
+static int uv_nmi_retry_count = 500;
+module_param_named(retry_count, uv_nmi_retry_count, int, 0644);
+
+/*
+ * Valid NMI Actions:
+ * "dump" - dump process stack for each cpu
+ * "ips" - dump IP info for each cpu
+ * "kdump" - do crash dump
+ * "kdb" - enter KDB/KGDB (default)
+ */
+static char uv_nmi_action[8] = "kdb";
+module_param_string(action, uv_nmi_action, sizeof(uv_nmi_action), 0644);
+
+static inline bool uv_nmi_action_is(const char *action)
+{
+ return (strncmp(uv_nmi_action, action, strlen(action)) == 0);
+}
+
+/* Setup which NMI support is present in system */
+static void uv_nmi_setup_mmrs(void)
+{
+ if (uv_read_local_mmr(UVH_NMI_MMRX_SUPPORTED)) {
+ uv_write_local_mmr(UVH_NMI_MMRX_REQ,
+ 1UL << UVH_NMI_MMRX_REQ_SHIFT);
+ nmi_mmr = UVH_NMI_MMRX;
+ nmi_mmr_clear = UVH_NMI_MMRX_CLEAR;
+ nmi_mmr_pending = 1UL << UVH_NMI_MMRX_SHIFT;
+ pr_info("UV: SMI NMI support: %s\n", UVH_NMI_MMRX_TYPE);
+ } else {
+ nmi_mmr = UVH_NMI_MMR;
+ nmi_mmr_clear = UVH_NMI_MMR_CLEAR;
+ nmi_mmr_pending = 1UL << UVH_NMI_MMR_SHIFT;
+ pr_info("UV: SMI NMI support: %s\n", UVH_NMI_MMR_TYPE);
+ }
+}
+
+/* Read NMI MMR and check if NMI flag was set by BMC. */
+static inline int uv_nmi_test_mmr(struct uv_hub_nmi_s *hub_nmi)
+{
+ hub_nmi->nmi_value = uv_read_local_mmr(nmi_mmr);
+ atomic_inc(&hub_nmi->read_mmr_count);
+ return !!(hub_nmi->nmi_value & nmi_mmr_pending);
+}
+
+static inline void uv_local_mmr_clear_nmi(void)
+{
+ uv_write_local_mmr(nmi_mmr_clear, nmi_mmr_pending);
+}
+
+/*
+ * If first cpu in on this hub, set hub_nmi "in_nmi" and "owner" values and
+ * return true. If first cpu in on the system, set global "in_nmi" flag.
+ */
+static int uv_set_in_nmi(int cpu, struct uv_hub_nmi_s *hub_nmi)
+{
+ int first = atomic_add_unless(&hub_nmi->in_nmi, 1, 1);
+
+ if (first) {
+ atomic_set(&hub_nmi->cpu_owner, cpu);
+ if (atomic_add_unless(&uv_in_nmi, 1, 1))
+ atomic_set(&uv_nmi_cpu, cpu);
+
+ atomic_inc(&hub_nmi->nmi_count);
+ }
+ return first;
+}
+
+/* Check if this is a system NMI event */
+static int uv_check_nmi(struct uv_hub_nmi_s *hub_nmi)
+{
+ int cpu = smp_processor_id();
+ int nmi = 0;
+
+ local64_inc(&uv_nmi_count);
+ uv_cpu_nmi.queries++;
+
+ do {
+ nmi = atomic_read(&hub_nmi->in_nmi);
+ if (nmi)
+ break;
+
+ if (raw_spin_trylock(&hub_nmi->nmi_lock)) {
+
+ /* check hub MMR NMI flag */
+ if (uv_nmi_test_mmr(hub_nmi)) {
+ uv_set_in_nmi(cpu, hub_nmi);
+ nmi = 1;
+ break;
+ }
+
+ /* MMR NMI flag is clear */
+ raw_spin_unlock(&hub_nmi->nmi_lock);
+
+ } else {
+ /* wait a moment for the hub nmi locker to set flag */
+ cpu_relax();
+ udelay(uv_nmi_slave_delay);
+
+ /* re-check hub in_nmi flag */
+ nmi = atomic_read(&hub_nmi->in_nmi);
+ if (nmi)
+ break;
+ }
+
+ /* check if this BMC missed setting the MMR NMI flag */
+ if (!nmi) {
+ nmi = atomic_read(&uv_in_nmi);
+ if (nmi)
+ uv_set_in_nmi(cpu, hub_nmi);
+ }
+
+ } while (0);
+
+ if (!nmi)
+ local64_inc(&uv_nmi_misses);
+
+ return nmi;
+}
+
+/* Need to reset the NMI MMR register, but only once per hub. */
+static inline void uv_clear_nmi(int cpu)
+{
+ struct uv_hub_nmi_s *hub_nmi = uv_hub_nmi;
+
+ if (cpu == atomic_read(&hub_nmi->cpu_owner)) {
+ atomic_set(&hub_nmi->cpu_owner, -1);
+ atomic_set(&hub_nmi->in_nmi, 0);
+ uv_local_mmr_clear_nmi();
+ raw_spin_unlock(&hub_nmi->nmi_lock);
+ }
+}
+
+/* Print non-responding cpus */
+static void uv_nmi_nr_cpus_pr(char *fmt)
+{
+ static char cpu_list[1024];
+ int len = sizeof(cpu_list);
+ int c = cpumask_weight(uv_nmi_cpu_mask);
+ int n = cpulist_scnprintf(cpu_list, len, uv_nmi_cpu_mask);
+
+ if (n >= len-1)
+ strcpy(&cpu_list[len - 6], "...\n");
+
+ printk(fmt, c, cpu_list);
+}
+
+/* Ping non-responding cpus attemping to force them into the NMI handler */
+static void uv_nmi_nr_cpus_ping(void)
+{
+ int cpu;
+
+ for_each_cpu(cpu, uv_nmi_cpu_mask)
+ atomic_set(&uv_cpu_nmi_per(cpu).pinging, 1);
+
+ apic->send_IPI_mask(uv_nmi_cpu_mask, APIC_DM_NMI);
+}
+
+/* Clean up flags for cpus that ignored both NMI and ping */
+static void uv_nmi_cleanup_mask(void)
+{
+ int cpu;
+
+ for_each_cpu(cpu, uv_nmi_cpu_mask) {
+ atomic_set(&uv_cpu_nmi_per(cpu).pinging, 0);
+ atomic_set(&uv_cpu_nmi_per(cpu).state, UV_NMI_STATE_OUT);
+ cpumask_clear_cpu(cpu, uv_nmi_cpu_mask);
+ }
+}
+
+/* Loop waiting as cpus enter nmi handler */
+static int uv_nmi_wait_cpus(int first)
+{
+ int i, j, k, n = num_online_cpus();
+ int last_k = 0, waiting = 0;
+
+ if (first) {
+ cpumask_copy(uv_nmi_cpu_mask, cpu_online_mask);
+ k = 0;
+ } else {
+ k = n - cpumask_weight(uv_nmi_cpu_mask);
+ }
+
+ udelay(uv_nmi_initial_delay);
+ for (i = 0; i < uv_nmi_retry_count; i++) {
+ int loop_delay = uv_nmi_loop_delay;
+
+ for_each_cpu(j, uv_nmi_cpu_mask) {
+ if (atomic_read(&uv_cpu_nmi_per(j).state)) {
+ cpumask_clear_cpu(j, uv_nmi_cpu_mask);
+ if (++k >= n)
+ break;
+ }
+ }
+ if (k >= n) { /* all in? */
+ k = n;
+ break;
+ }
+ if (last_k != k) { /* abort if no new cpus coming in */
+ last_k = k;
+ waiting = 0;
+ } else if (++waiting > uv_nmi_wait_count)
+ break;
+
+ /* extend delay if waiting only for cpu 0 */
+ if (waiting && (n - k) == 1 &&
+ cpumask_test_cpu(0, uv_nmi_cpu_mask))
+ loop_delay *= 100;
+
+ udelay(loop_delay);
+ }
+ atomic_set(&uv_nmi_cpus_in_nmi, k);
+ return n - k;
+}
+
+/* Wait until all slave cpus have entered UV NMI handler */
+static void uv_nmi_wait(int master)
+{
+ /* indicate this cpu is in */
+ atomic_set(&uv_cpu_nmi.state, UV_NMI_STATE_IN);
+
+ /* if not the first cpu in (the master), then we are a slave cpu */
+ if (!master)
+ return;
+
+ do {
+ /* wait for all other cpus to gather here */
+ if (!uv_nmi_wait_cpus(1))
+ break;
+
+ /* if not all made it in, send IPI NMI to them */
+ uv_nmi_nr_cpus_pr(KERN_ALERT
+ "UV: Sending NMI IPI to %d non-responding CPUs: %s\n");
+ uv_nmi_nr_cpus_ping();
+
+ /* if all cpus are in, then done */
+ if (!uv_nmi_wait_cpus(0))
+ break;
+
+ uv_nmi_nr_cpus_pr(KERN_ALERT
+ "UV: %d CPUs not in NMI loop: %s\n");
+ } while (0);
+
+ pr_alert("UV: %d of %d CPUs in NMI\n",
+ atomic_read(&uv_nmi_cpus_in_nmi), num_online_cpus());
+}
+
+static void uv_nmi_dump_cpu_ip_hdr(void)
+{
+ printk(KERN_DEFAULT
+ "\nUV: %4s %6s %-32s %s (Note: PID 0 not listed)\n",
+ "CPU", "PID", "COMMAND", "IP");
+}
+
+static void uv_nmi_dump_cpu_ip(int cpu, struct pt_regs *regs)
+{
+ printk(KERN_DEFAULT "UV: %4d %6d %-32.32s ",
+ cpu, current->pid, current->comm);
+
+ printk_address(regs->ip, 1);
+}
+
+/* Dump this cpu's state */
+static void uv_nmi_dump_state_cpu(int cpu, struct pt_regs *regs)
+{
+ const char *dots = " ................................. ";
+
+ if (uv_nmi_action_is("ips")) {
+ if (cpu == 0)
+ uv_nmi_dump_cpu_ip_hdr();
+
+ if (current->pid != 0)
+ uv_nmi_dump_cpu_ip(cpu, regs);
+
+ } else if (uv_nmi_action_is("dump")) {
+ printk(KERN_DEFAULT
+ "UV:%sNMI process trace for CPU %d\n", dots, cpu);
+ show_regs(regs);
+ }
+ atomic_set(&uv_cpu_nmi.state, UV_NMI_STATE_DUMP_DONE);
+}
+
+/* Trigger a slave cpu to dump it's state */
+static void uv_nmi_trigger_dump(int cpu)
+{
+ int retry = uv_nmi_trigger_delay;
+
+ if (atomic_read(&uv_cpu_nmi_per(cpu).state) != UV_NMI_STATE_IN)
+ return;
+
+ atomic_set(&uv_cpu_nmi_per(cpu).state, UV_NMI_STATE_DUMP);
+ do {
+ cpu_relax();
+ udelay(10);
+ if (atomic_read(&uv_cpu_nmi_per(cpu).state)
+ != UV_NMI_STATE_DUMP)
+ return;
+ } while (--retry > 0);
+
+ pr_crit("UV: CPU %d stuck in process dump function\n", cpu);
+ atomic_set(&uv_cpu_nmi_per(cpu).state, UV_NMI_STATE_DUMP_DONE);
+}
+
+/* Wait until all cpus ready to exit */
+static void uv_nmi_sync_exit(int master)
+{
+ atomic_dec(&uv_nmi_cpus_in_nmi);
+ if (master) {
+ while (atomic_read(&uv_nmi_cpus_in_nmi) > 0)
+ cpu_relax();
+ atomic_set(&uv_nmi_slave_continue, SLAVE_CLEAR);
+ } else {
+ while (atomic_read(&uv_nmi_slave_continue))
+ cpu_relax();
+ }
+}
+
+/* Walk through cpu list and dump state of each */
+static void uv_nmi_dump_state(int cpu, struct pt_regs *regs, int master)
+{
+ if (master) {
+ int tcpu;
+ int ignored = 0;
+ int saved_console_loglevel = console_loglevel;
+
+ pr_alert("UV: tracing %s for %d CPUs from CPU %d\n",
+ uv_nmi_action_is("ips") ? "IPs" : "processes",
+ atomic_read(&uv_nmi_cpus_in_nmi), cpu);
+
+ console_loglevel = uv_nmi_loglevel;
+ atomic_set(&uv_nmi_slave_continue, SLAVE_EXIT);
+ for_each_online_cpu(tcpu) {
+ if (cpumask_test_cpu(tcpu, uv_nmi_cpu_mask))
+ ignored++;
+ else if (tcpu == cpu)
+ uv_nmi_dump_state_cpu(tcpu, regs);
+ else
+ uv_nmi_trigger_dump(tcpu);
+ }
+ if (ignored)
+ printk(KERN_DEFAULT "UV: %d CPUs ignored NMI\n",
+ ignored);
+
+ console_loglevel = saved_console_loglevel;
+ pr_alert("UV: process trace complete\n");
+ } else {
+ while (!atomic_read(&uv_nmi_slave_continue))
+ cpu_relax();
+ while (atomic_read(&uv_cpu_nmi.state) != UV_NMI_STATE_DUMP)
+ cpu_relax();
+ uv_nmi_dump_state_cpu(cpu, regs);
+ }
+ uv_nmi_sync_exit(master);
+}
+
+static void uv_nmi_touch_watchdogs(void)
+{
+ touch_softlockup_watchdog_sync();
+ clocksource_touch_watchdog();
+ rcu_cpu_stall_reset();
+ touch_nmi_watchdog();
+}
+
+#if defined(CONFIG_KEXEC)
+static void uv_nmi_kdump(int cpu, int master, struct pt_regs *regs)
+{
+ /* Call crash to dump system state */
+ if (master) {
+ pr_emerg("UV: NMI executing crash_kexec on CPU%d\n", cpu);
+ crash_kexec(regs);
+
+ pr_emerg("UV: crash_kexec unexpectedly returned, ");
+ if (!kexec_crash_image) {
+ pr_cont("crash kernel not loaded\n");
+ atomic_set(&uv_nmi_kexec_failed, 1);
+ uv_nmi_sync_exit(1);
+ return;
+ }
+ pr_cont("kexec busy, stalling cpus while waiting\n");
+ }
+
+ /* If crash exec fails the slaves should return, otherwise stall */
+ while (atomic_read(&uv_nmi_kexec_failed) == 0)
+ mdelay(10);
+
+ /* Crash kernel most likely not loaded, return in an orderly fashion */
+ uv_nmi_sync_exit(0);
+}
+
+#else /* !CONFIG_KEXEC */
+static inline void uv_nmi_kdump(int cpu, int master, struct pt_regs *regs)
+{
+ if (master)
+ pr_err("UV: NMI kdump: KEXEC not supported in this kernel\n");
+}
+#endif /* !CONFIG_KEXEC */
+
+#ifdef CONFIG_KGDB_KDB
+/* Call KDB from NMI handler */
+static void uv_call_kdb(int cpu, struct pt_regs *regs, int master)
+{
+ int ret;
+
+ if (master) {
+ /* call KGDB NMI handler as MASTER */
+ ret = kgdb_nmicallin(cpu, X86_TRAP_NMI, regs,
+ &uv_nmi_slave_continue);
+ if (ret) {
+ pr_alert("KDB returned error, is kgdboc set?\n");
+ atomic_set(&uv_nmi_slave_continue, SLAVE_EXIT);
+ }
+ } else {
+ /* wait for KGDB signal that it's ready for slaves to enter */
+ int sig;
+
+ do {
+ cpu_relax();
+ sig = atomic_read(&uv_nmi_slave_continue);
+ } while (!sig);
+
+ /* call KGDB as slave */
+ if (sig == SLAVE_CONTINUE)
+ kgdb_nmicallback(cpu, regs);
+ }
+ uv_nmi_sync_exit(master);
+}
+
+#else /* !CONFIG_KGDB_KDB */
+static inline void uv_call_kdb(int cpu, struct pt_regs *regs, int master)
+{
+ pr_err("UV: NMI error: KGDB/KDB is not enabled in this kernel\n");
+}
+#endif /* !CONFIG_KGDB_KDB */
+
+/*
+ * UV NMI handler
+ */
+int uv_handle_nmi(unsigned int reason, struct pt_regs *regs)
+{
+ struct uv_hub_nmi_s *hub_nmi = uv_hub_nmi;
+ int cpu = smp_processor_id();
+ int master = 0;
+ unsigned long flags;
+
+ local_irq_save(flags);
+
+ /* If not a UV System NMI, ignore */
+ if (!atomic_read(&uv_cpu_nmi.pinging) && !uv_check_nmi(hub_nmi)) {
+ local_irq_restore(flags);
+ return NMI_DONE;
+ }
+
+ /* Indicate we are the first CPU into the NMI handler */
+ master = (atomic_read(&uv_nmi_cpu) == cpu);
+
+ /* If NMI action is "kdump", then attempt to do it */
+ if (uv_nmi_action_is("kdump"))
+ uv_nmi_kdump(cpu, master, regs);
+
+ /* Pause as all cpus enter the NMI handler */
+ uv_nmi_wait(master);
+
+ /* Dump state of each cpu */
+ if (uv_nmi_action_is("ips") || uv_nmi_action_is("dump"))
+ uv_nmi_dump_state(cpu, regs, master);
+
+ /* Call KDB if enabled */
+ else if (uv_nmi_action_is("kdb"))
+ uv_call_kdb(cpu, regs, master);
+
+ /* Clear per_cpu "in nmi" flag */
+ atomic_set(&uv_cpu_nmi.state, UV_NMI_STATE_OUT);
+
+ /* Clear MMR NMI flag on each hub */
+ uv_clear_nmi(cpu);
+
+ /* Clear global flags */
+ if (master) {
+ if (cpumask_weight(uv_nmi_cpu_mask))
+ uv_nmi_cleanup_mask();
+ atomic_set(&uv_nmi_cpus_in_nmi, -1);
+ atomic_set(&uv_nmi_cpu, -1);
+ atomic_set(&uv_in_nmi, 0);
+ }
+
+ uv_nmi_touch_watchdogs();
+ local_irq_restore(flags);
+
+ return NMI_HANDLED;
+}
+
+/*
+ * NMI handler for pulling in CPUs when perf events are grabbing our NMI
+ */
+int uv_handle_nmi_ping(unsigned int reason, struct pt_regs *regs)
+{
+ int ret;
+
+ uv_cpu_nmi.queries++;
+ if (!atomic_read(&uv_cpu_nmi.pinging)) {
+ local64_inc(&uv_nmi_ping_misses);
+ return NMI_DONE;
+ }
+
+ uv_cpu_nmi.pings++;
+ local64_inc(&uv_nmi_ping_count);
+ ret = uv_handle_nmi(reason, regs);
+ atomic_set(&uv_cpu_nmi.pinging, 0);
+ return ret;
+}
+
+void uv_register_nmi_notifier(void)
+{
+ if (register_nmi_handler(NMI_UNKNOWN, uv_handle_nmi, 0, "uv"))
+ pr_warn("UV: NMI handler failed to register\n");
+
+ if (register_nmi_handler(NMI_LOCAL, uv_handle_nmi_ping, 0, "uvping"))
+ pr_warn("UV: PING NMI handler failed to register\n");
+}
+
+void uv_nmi_init(void)
+{
+ unsigned int value;
+
+ /*
+ * Unmask NMI on all cpus
+ */
+ value = apic_read(APIC_LVT1) | APIC_DM_NMI;
+ value &= ~APIC_LVT_MASKED;
+ apic_write(APIC_LVT1, value);
+}
+
+void uv_nmi_setup(void)
+{
+ int size = sizeof(void *) * (1 << NODES_SHIFT);
+ int cpu, nid;
+
+ /* Setup hub nmi info */
+ uv_nmi_setup_mmrs();
+ uv_hub_nmi_list = kzalloc(size, GFP_KERNEL);
+ pr_info("UV: NMI hub list @ 0x%p (%d)\n", uv_hub_nmi_list, size);
+ BUG_ON(!uv_hub_nmi_list);
+ size = sizeof(struct uv_hub_nmi_s);
+ for_each_present_cpu(cpu) {
+ nid = cpu_to_node(cpu);
+ if (uv_hub_nmi_list[nid] == NULL) {
+ uv_hub_nmi_list[nid] = kzalloc_node(size,
+ GFP_KERNEL, nid);
+ BUG_ON(!uv_hub_nmi_list[nid]);
+ raw_spin_lock_init(&(uv_hub_nmi_list[nid]->nmi_lock));
+ atomic_set(&uv_hub_nmi_list[nid]->cpu_owner, -1);
+ }
+ uv_hub_nmi_per(cpu) = uv_hub_nmi_list[nid];
+ }
+ BUG_ON(!alloc_cpumask_var(&uv_nmi_cpu_mask, GFP_KERNEL));
+}
+
+
diff --git a/include/linux/kdb.h b/include/linux/kdb.h
index 7f6fe6e..290db12 100644
--- a/include/linux/kdb.h
+++ b/include/linux/kdb.h
@@ -109,6 +109,7 @@ typedef enum {
KDB_REASON_RECURSE, /* Recursive entry to kdb;
* regs probably valid */
KDB_REASON_SSTEP, /* Single Step trap. - regs valid */
+ KDB_REASON_SYSTEM_NMI, /* In NMI due to SYSTEM cmd; regs valid */
} kdb_reason_t;
extern int kdb_trap_printk;
diff --git a/include/linux/kgdb.h b/include/linux/kgdb.h
index c6e091b..dfb4f2f 100644
--- a/include/linux/kgdb.h
+++ b/include/linux/kgdb.h
@@ -310,6 +310,7 @@ extern int
kgdb_handle_exception(int ex_vector, int signo, int err_code,
struct pt_regs *regs);
extern int kgdb_nmicallback(int cpu, void *regs);
+extern int kgdb_nmicallin(int cpu, int trapnr, void *regs, atomic_t *snd_rdy);
extern void gdbstub_exit(int status);
extern int kgdb_single_step;
diff --git a/kernel/debug/debug_core.c b/kernel/debug/debug_core.c
index 0506d44..7d2f35e 100644
--- a/kernel/debug/debug_core.c
+++ b/kernel/debug/debug_core.c
@@ -575,8 +575,12 @@ return_normal:
raw_spin_lock(&dbg_slave_lock);
#ifdef CONFIG_SMP
+ /* If send_ready set, slaves are already waiting */
+ if (ks->send_ready)
+ atomic_set(ks->send_ready, 1);
+
/* Signal the other CPUs to enter kgdb_wait() */
- if ((!kgdb_single_step) && kgdb_do_roundup)
+ else if ((!kgdb_single_step) && kgdb_do_roundup)
kgdb_roundup_cpus(flags);
#endif
@@ -678,11 +682,11 @@ kgdb_handle_exception(int evector, int signo, int ecode, struct pt_regs *regs)
if (arch_kgdb_ops.enable_nmi)
arch_kgdb_ops.enable_nmi(0);
+ memset(ks, 0, sizeof(struct kgdb_state));
ks->cpu = raw_smp_processor_id();
ks->ex_vector = evector;
ks->signo = signo;
ks->err_code = ecode;
- ks->kgdb_usethreadid = 0;
ks->linux_regs = regs;
if (kgdb_reenter_check(ks))
@@ -732,6 +736,30 @@ int kgdb_nmicallback(int cpu, void *regs)
return 1;
}
+int kgdb_nmicallin(int cpu, int trapnr, void *regs, atomic_t *send_ready)
+{
+#ifdef CONFIG_SMP
+ if (!kgdb_io_ready(0) || !send_ready)
+ return 1;
+
+ if (kgdb_info[cpu].enter_kgdb == 0) {
+ struct kgdb_state kgdb_var;
+ struct kgdb_state *ks = &kgdb_var;
+
+ memset(ks, 0, sizeof(struct kgdb_state));
+ ks->cpu = cpu;
+ ks->ex_vector = trapnr;
+ ks->signo = SIGTRAP;
+ ks->err_code = KGDB_KDB_REASON_SYSTEM_NMI;
+ ks->linux_regs = regs;
+ ks->send_ready = send_ready;
+ kgdb_cpu_enter(ks, regs, DCPU_WANT_MASTER);
+ return 0;
+ }
+#endif
+ return 1;
+}
+
static void kgdb_console_write(struct console *co, const char *s,
unsigned count)
{
diff --git a/kernel/debug/debug_core.h b/kernel/debug/debug_core.h
index 2235967..572aa4f 100644
--- a/kernel/debug/debug_core.h
+++ b/kernel/debug/debug_core.h
@@ -26,6 +26,7 @@ struct kgdb_state {
unsigned long threadid;
long kgdb_usethreadid;
struct pt_regs *linux_regs;
+ atomic_t *send_ready;
};
/* Exception state values */
@@ -74,11 +75,13 @@ extern int kdb_stub(struct kgdb_state *ks);
extern int kdb_parse(const char *cmdstr);
extern int kdb_common_init_state(struct kgdb_state *ks);
extern int kdb_common_deinit_state(void);
+#define KGDB_KDB_REASON_SYSTEM_NMI KDB_REASON_SYSTEM_NMI
#else /* ! CONFIG_KGDB_KDB */
static inline int kdb_stub(struct kgdb_state *ks)
{
return DBG_PASS_EVENT;
}
+#define KGDB_KDB_REASON_SYSTEM_NMI 0
#endif /* CONFIG_KGDB_KDB */
#endif /* _DEBUG_CORE_H_ */
diff --git a/kernel/debug/kdb/kdb_debugger.c b/kernel/debug/kdb/kdb_debugger.c
index 328d18e..8859ca3 100644
--- a/kernel/debug/kdb/kdb_debugger.c
+++ b/kernel/debug/kdb/kdb_debugger.c
@@ -69,7 +69,10 @@ int kdb_stub(struct kgdb_state *ks)
if (atomic_read(&kgdb_setting_breakpoint))
reason = KDB_REASON_KEYBOARD;
- if (in_nmi())
+ if (ks->err_code == KDB_REASON_SYSTEM_NMI && ks->signo == SIGTRAP)
+ reason = KDB_REASON_SYSTEM_NMI;
+
+ else if (in_nmi())
reason = KDB_REASON_NMI;
for (i = 0, bp = kdb_breakpoints; i < KDB_MAXBPT; i++, bp++) {
diff --git a/kernel/debug/kdb/kdb_main.c b/kernel/debug/kdb/kdb_main.c
index 00eb8f7..0b097c8 100644
--- a/kernel/debug/kdb/kdb_main.c
+++ b/kernel/debug/kdb/kdb_main.c
@@ -1200,6 +1200,9 @@ static int kdb_local(kdb_reason_t reason, int error, struct pt_regs *regs,
instruction_pointer(regs));
kdb_dumpregs(regs);
break;
+ case KDB_REASON_SYSTEM_NMI:
+ kdb_printf("due to System NonMaskable Interrupt\n");
+ break;
case KDB_REASON_NMI:
kdb_printf("due to NonMaskable Interrupt @ "
kdb_machreg_fmt "\n",
--
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