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-rw-r--r--sys/amd64/amd64/mp_machdep.c74
-rw-r--r--sys/amd64/amd64/trap.c8
-rw-r--r--sys/amd64/conf/NOTES6
-rw-r--r--sys/amd64/include/smp.h5
-rw-r--r--sys/conf/options.amd643
-rw-r--r--sys/conf/options.i3863
-rw-r--r--sys/i386/conf/NOTES5
-rw-r--r--sys/i386/i386/mp_machdep.c74
-rw-r--r--sys/i386/i386/trap.c8
-rw-r--r--sys/i386/include/smp.h5
-rw-r--r--sys/kern/subr_kdb.c50
-rw-r--r--sys/kern/subr_smp.c29
-rw-r--r--sys/sys/smp.h4
13 files changed, 274 insertions, 0 deletions
diff --git a/sys/amd64/amd64/mp_machdep.c b/sys/amd64/amd64/mp_machdep.c
index 9d3bf8f..d1e4cb2 100644
--- a/sys/amd64/amd64/mp_machdep.c
+++ b/sys/amd64/amd64/mp_machdep.c
@@ -192,6 +192,10 @@ mp_topology(void)
}
+#ifdef KDB_STOP_NMI
+volatile cpumask_t ipi_nmi_pending;
+#endif
+
/*
* Calculate usable address in base memory for AP trampoline code.
*/
@@ -972,6 +976,76 @@ ipi_self(u_int ipi)
lapic_ipi_vectored(ipi, APIC_IPI_DEST_SELF);
}
+#ifdef KDB_STOP_NMI
+/*
+ * send NMI IPI to selected CPUs
+ */
+
+#define BEFORE_SPIN 1000000
+
+void
+ipi_nmi_selected(u_int32_t cpus)
+{
+
+ int cpu;
+ register_t icrlo;
+
+ icrlo = APIC_DELMODE_NMI | APIC_DESTMODE_PHY | APIC_LEVEL_ASSERT
+ | APIC_TRIGMOD_EDGE;
+
+ CTR2(KTR_SMP, "%s: cpus: %x nmi", __func__, cpus);
+
+
+ atomic_set_int(&ipi_nmi_pending, cpus);
+
+
+ while ((cpu = ffs(cpus)) != 0) {
+ cpu--;
+ cpus &= ~(1 << cpu);
+
+ KASSERT(cpu_apic_ids[cpu] != -1,
+ ("IPI NMI to non-existent CPU %d", cpu));
+
+ /* Wait for an earlier IPI to finish. */
+ if (!lapic_ipi_wait(BEFORE_SPIN))
+ panic("ipi_nmi_selected: previous IPI has not cleared");
+
+ lapic_ipi_raw(icrlo,cpu_apic_ids[cpu]);
+ }
+}
+
+
+int
+ipi_nmi_handler()
+{
+ int cpu = PCPU_GET(cpuid);
+
+ if(!(atomic_load_acq_int(&ipi_nmi_pending) & (1 << cpu)))
+ return 1;
+
+ atomic_clear_int(&ipi_nmi_pending,1 << cpu);
+
+ savectx(&stoppcbs[cpu]);
+
+ /* Indicate that we are stopped */
+ atomic_set_int(&stopped_cpus,1 << cpu);
+
+
+ /* Wait for restart */
+ while(!(atomic_load_acq_int(&started_cpus) & (1 << cpu)))
+ ia32_pause();
+
+ atomic_clear_int(&started_cpus,1 << cpu);
+ atomic_clear_int(&stopped_cpus,1 << cpu);
+
+ if(cpu == 0 && cpustop_restartfunc != NULL)
+ cpustop_restartfunc();
+
+ return 0;
+}
+
+#endif /* KDB_STOP_NMI */
+
/*
* This is called once the rest of the system is up and running and we're
* ready to let the AP's out of the pen.
diff --git a/sys/amd64/amd64/trap.c b/sys/amd64/amd64/trap.c
index 7baaeee..9820f87 100644
--- a/sys/amd64/amd64/trap.c
+++ b/sys/amd64/amd64/trap.c
@@ -165,6 +165,14 @@ trap(frame)
PCPU_LAZY_INC(cnt.v_trap);
type = frame.tf_trapno;
+#ifdef KDB_STOP_NMI
+ /* Handler for NMI IPIs used for debugging */
+ if (type == T_NMI) {
+ if (ipi_nmi_handler() == 0)
+ goto out;
+ }
+#endif /* KDB_STOP_NMI */
+
#ifdef KDB
if (kdb_active) {
kdb_reenter();
diff --git a/sys/amd64/conf/NOTES b/sys/amd64/conf/NOTES
index 6677fbe..8978c55 100644
--- a/sys/amd64/conf/NOTES
+++ b/sys/amd64/conf/NOTES
@@ -33,6 +33,12 @@ device mptable # Optional MPSPEC mptable support
#
options MP_WATCHDOG
+#
+# Debugging options.
+#
+options KDB_STOP_NMI # Stop CPUS using NMI instead of IPI
+
+
#####################################################################
# CPU OPTIONS
diff --git a/sys/amd64/include/smp.h b/sys/amd64/include/smp.h
index 8aea3b9..2c63dc9 100644
--- a/sys/amd64/include/smp.h
+++ b/sys/amd64/include/smp.h
@@ -63,6 +63,11 @@ void smp_masked_invlpg_range(u_int mask, vm_offset_t startva,
void smp_invltlb(void);
void smp_masked_invltlb(u_int mask);
+#ifdef KDB_STOP_NMI
+int ipi_nmi_handler(void);
+void ipi_nmi_selected(u_int32_t cpus);
+#endif
+
#endif /* !LOCORE */
#endif /* SMP */
diff --git a/sys/conf/options.amd64 b/sys/conf/options.amd64
index 82f864d..0227bfd 100644
--- a/sys/conf/options.amd64
+++ b/sys/conf/options.amd64
@@ -55,3 +55,6 @@ PSM_HOOKRESUME opt_psm.h
PSM_RESETAFTERSUSPEND opt_psm.h
PSM_DEBUG opt_psm.h
DEV_ATPIC opt_atpic.h
+
+# Debugging
+KDB_STOP_NMI opt_global.h
diff --git a/sys/conf/options.i386 b/sys/conf/options.i386
index a1dfee6..405614f 100644
--- a/sys/conf/options.i386
+++ b/sys/conf/options.i386
@@ -160,3 +160,6 @@ IPR_LOG opt_i4b.h
DEV_APIC opt_apic.h
DEV_NPX opt_npx.h
ASR_COMPAT opt_asr.h
+
+# Debugging
+KDB_STOP_NMI opt_global.h
diff --git a/sys/i386/conf/NOTES b/sys/i386/conf/NOTES
index 3c34894..82b2c6a 100644
--- a/sys/i386/conf/NOTES
+++ b/sys/i386/conf/NOTES
@@ -51,6 +51,11 @@ options MPTABLE_FORCE_HTT # Enable HTT CPUs with the MP Table
#
options MP_WATCHDOG
+# Debugging options.
+#
+options KDB_STOP_NMI # Stop CPUS using NMI instead of IPI
+
+
#####################################################################
# CPU OPTIONS
diff --git a/sys/i386/i386/mp_machdep.c b/sys/i386/i386/mp_machdep.c
index d601f6d..2fc958c 100644
--- a/sys/i386/i386/mp_machdep.c
+++ b/sys/i386/i386/mp_machdep.c
@@ -175,6 +175,10 @@ vm_offset_t smp_tlb_addr1;
vm_offset_t smp_tlb_addr2;
volatile int smp_tlb_wait;
+#ifdef KDB_STOP_NMI
+volatile cpumask_t ipi_nmi_pending;
+#endif
+
/*
* Local data and functions.
*/
@@ -1191,6 +1195,76 @@ ipi_self(u_int ipi)
lapic_ipi_vectored(ipi, APIC_IPI_DEST_SELF);
}
+#ifdef KDB_STOP_NMI
+/*
+ * send NMI IPI to selected CPUs
+ */
+
+#define BEFORE_SPIN 1000000
+
+void
+ipi_nmi_selected(u_int32_t cpus)
+{
+
+ int cpu;
+ register_t icrlo;
+
+ icrlo = APIC_DELMODE_NMI | APIC_DESTMODE_PHY | APIC_LEVEL_ASSERT
+ | APIC_TRIGMOD_EDGE;
+
+ CTR2(KTR_SMP, "%s: cpus: %x nmi", __func__, cpus);
+
+
+ atomic_set_int(&ipi_nmi_pending, cpus);
+
+
+ while ((cpu = ffs(cpus)) != 0) {
+ cpu--;
+ cpus &= ~(1 << cpu);
+
+ KASSERT(cpu_apic_ids[cpu] != -1,
+ ("IPI NMI to non-existent CPU %d", cpu));
+
+ /* Wait for an earlier IPI to finish. */
+ if (!lapic_ipi_wait(BEFORE_SPIN))
+ panic("ipi_nmi_selected: previous IPI has not cleared");
+
+ lapic_ipi_raw(icrlo,cpu_apic_ids[cpu]);
+ }
+}
+
+
+int
+ipi_nmi_handler()
+{
+ int cpu = PCPU_GET(cpuid);
+
+ if(!(atomic_load_acq_int(&ipi_nmi_pending) & (1 << cpu)))
+ return 1;
+
+ atomic_clear_int(&ipi_nmi_pending,1 << cpu);
+
+ savectx(&stoppcbs[cpu]);
+
+ /* Indicate that we are stopped */
+ atomic_set_int(&stopped_cpus,1 << cpu);
+
+
+ /* Wait for restart */
+ while(!(atomic_load_acq_int(&started_cpus) & (1 << cpu)))
+ ia32_pause();
+
+ atomic_clear_int(&started_cpus,1 << cpu);
+ atomic_clear_int(&stopped_cpus,1 << cpu);
+
+ if(cpu == 0 && cpustop_restartfunc != NULL)
+ cpustop_restartfunc();
+
+ return 0;
+}
+
+#endif /* KDB_STOP_NMI */
+
/*
* This is called once the rest of the system is up and running and we're
* ready to let the AP's out of the pen.
diff --git a/sys/i386/i386/trap.c b/sys/i386/i386/trap.c
index ae2b4ed..2bca068 100644
--- a/sys/i386/i386/trap.c
+++ b/sys/i386/i386/trap.c
@@ -183,6 +183,14 @@ trap(frame)
PCPU_LAZY_INC(cnt.v_trap);
type = frame.tf_trapno;
+#ifdef KDB_STOP_NMI
+ /* Handler for NMI IPIs used for debugging */
+ if (type == T_NMI) {
+ if (ipi_nmi_handler() == 0)
+ goto out;
+ }
+#endif /* KDB_STOP_NMI */
+
#ifdef KDB
if (kdb_active) {
kdb_reenter();
diff --git a/sys/i386/include/smp.h b/sys/i386/include/smp.h
index 7837120..4c9ae76 100644
--- a/sys/i386/include/smp.h
+++ b/sys/i386/include/smp.h
@@ -79,6 +79,11 @@ void smp_masked_invlpg_range(u_int mask, vm_offset_t startva,
void smp_invltlb(void);
void smp_masked_invltlb(u_int mask);
+#ifdef KDB_STOP_NMI
+int ipi_nmi_handler(void);
+void ipi_nmi_selected(u_int32_t cpus);
+#endif
+
#endif /* !LOCORE */
#endif /* SMP */
diff --git a/sys/kern/subr_kdb.c b/sys/kern/subr_kdb.c
index 54274db..5726a84 100644
--- a/sys/kern/subr_kdb.c
+++ b/sys/kern/subr_kdb.c
@@ -40,6 +40,18 @@ __FBSDID("$FreeBSD$");
#include <machine/kdb.h>
#include <machine/pcb.h>
+#ifdef KDB_STOP_NMI
+#include <machine/smp.h>
+#endif
+
+/*
+ * KDB_STOP_NMI requires SMP to pick up the right dependencies
+ * (And isn't useful on UP anyway)
+ */
+#if defined(KDB_STOP_NMI) && !defined(SMP)
+#error "options KDB_STOP_NMI" requires "options SMP"
+#endif
+
int kdb_active = 0;
void *kdb_jmpbufp = NULL;
struct kdb_dbbe *kdb_dbbe = NULL;
@@ -77,6 +89,19 @@ static int kdb_stop_cpus = 1;
SYSCTL_INT(_debug_kdb, OID_AUTO, stop_cpus, CTLTYPE_INT | CTLFLAG_RW,
&kdb_stop_cpus, 0, "");
TUNABLE_INT("debug.kdb.stop_cpus", &kdb_stop_cpus);
+
+#ifdef KDB_STOP_NMI
+/*
+ * Provide an alternate method of stopping other CPUs. If another CPU has
+ * disabled interrupts the conventional STOP IPI will be blocked. This
+ * NMI-based stop should get through in that case.
+ */
+static int kdb_stop_cpus_with_nmi = 0;
+SYSCTL_INT(_debug_kdb, OID_AUTO, stop_cpus_with_nmi, CTLTYPE_INT | CTLFLAG_RW,
+ &kdb_stop_cpus_with_nmi, 0, "");
+TUNABLE_INT("debug.kdb.stop_cpus_with_nmi", &kdb_stop_cpus_with_nmi);
+#endif /* KDB_STOP_NMI */
+
#endif
static int
@@ -308,9 +333,27 @@ kdb_reenter(void)
struct pcb *
kdb_thr_ctx(struct thread *thr)
+#ifdef KDB_STOP_NMI
+{
+ u_int cpuid;
+ struct pcpu *pc;
+
+ if (thr == curthread)
+ return &kdb_pcb;
+
+ SLIST_FOREACH(pc, &cpuhead, pc_allcpu) {
+ cpuid = pc->pc_cpuid;
+ if (pc->pc_curthread == thr && (atomic_load_acq_int(&stopped_cpus) & (1 << cpuid)))
+ return &stoppcbs[cpuid];
+ }
+
+ return thr->td_pcb;
+}
+#else
{
return ((thr == curthread) ? &kdb_pcb : thr->td_pcb);
}
+#endif /* KDB_STOP_NMI */
struct thread *
kdb_thr_first(void)
@@ -407,7 +450,14 @@ kdb_trap(int type, int code, struct trapframe *tf)
#ifdef SMP
if ((did_stop_cpus = kdb_stop_cpus) != 0)
+ {
+#ifdef KDB_STOP_NMI
+ if(kdb_stop_cpus_with_nmi)
+ stop_cpus_nmi(PCPU_GET(other_cpus));
+ else
+#endif /* KDB_STOP_NMI */
stop_cpus(PCPU_GET(other_cpus));
+ }
#endif
kdb_frame = tf;
diff --git a/sys/kern/subr_smp.c b/sys/kern/subr_smp.c
index aed3118..3d08ad8 100644
--- a/sys/kern/subr_smp.c
+++ b/sys/kern/subr_smp.c
@@ -254,6 +254,35 @@ stop_cpus(cpumask_t map)
return 1;
}
+#ifdef KDB_STOP_NMI
+int
+stop_cpus_nmi(cpumask_t map)
+{
+ int i;
+
+ if (!smp_started)
+ return 0;
+
+ CTR1(KTR_SMP, "stop_cpus(%x)", map);
+
+ /* send the stop IPI to all CPUs in map */
+ ipi_nmi_selected(map);
+
+ i = 0;
+ while ((atomic_load_acq_int(&stopped_cpus) & map) != map) {
+ /* spin */
+ i++;
+#ifdef DIAGNOSTIC
+ if (i == 100000) {
+ printf("timeout stopping cpus\n");
+ break;
+ }
+#endif
+ }
+
+ return 1;
+}
+#endif /* KDB_STOP_NMI */
/*
* Called by a CPU to restart stopped CPUs.
diff --git a/sys/sys/smp.h b/sys/sys/smp.h
index 88353fc..88c6ae2 100644
--- a/sys/sys/smp.h
+++ b/sys/sys/smp.h
@@ -101,6 +101,10 @@ int restart_cpus(cpumask_t);
int stop_cpus(cpumask_t);
void smp_rendezvous_action(void);
extern struct mtx smp_ipi_mtx;
+
+#ifdef KDB_STOP_NMI
+int stop_cpus_nmi(cpumask_t);
+#endif
#endif /* SMP */
void smp_rendezvous(void (*)(void *),
void (*)(void *),
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