aboutsummaryrefslogtreecommitdiff
diff options
context:
space:
mode:
authorLinus Torvalds <torvalds@linux-foundation.org>2017-08-11 08:56:01 -0700
committerLinus Torvalds <torvalds@linux-foundation.org>2017-08-11 08:56:01 -0700
commit8001a975f955f532d8d0c27b224d58646e202f2a (patch)
tree1cbd45380d5de43c8f0cee10cdcf092c997fb84f
parentb2dbdf2ca1d2803e9cdc46a94554c4a39ffb235a (diff)
parent96ea91e7b6ee2c406598d859e7348b4829404eea (diff)
downloadlinux-stericsson-8001a975f955f532d8d0c27b224d58646e202f2a.tar.gz
Merge tag 'powerpc-4.13-6' of git://git.kernel.org/pub/scm/linux/kernel/git/powerpc/linux
Pull powerpc fixes from Michael Ellerman: "All fixes for code that went in this cycle. - a revert of an optimisation to the syscall exit path, which could lead to an oops on either older machines or machines with > 1TB of memory - disable some deep idle states if the firmware configuration for them fails - re-enable HARD/SOFT lockup detectors in defconfigs after a Kconfig change - six fairly small patches fixing bugs in our new watchdog code Thanks to: Gautham R Shenoy, Nicholas Piggin" * tag 'powerpc-4.13-6' of git://git.kernel.org/pub/scm/linux/kernel/git/powerpc/linux: powerpc/watchdog: add locking around init/exit functions powerpc/watchdog: Fix marking of stuck CPUs powerpc/watchdog: Fix final-check recovered case powerpc/watchdog: Moderate touch_nmi_watchdog overhead powerpc/watchdog: Improve watchdog lock primitive powerpc: NMI IPI improve lock primitive powerpc/configs: Re-enable HARD/SOFT lockup detectors powerpc/powernv/idle: Disable LOSE_FULL_CONTEXT states when stop-api fails Revert "powerpc/64: Avoid restore_math call if possible in syscall exit"
-rw-r--r--arch/powerpc/configs/powernv_defconfig3
-rw-r--r--arch/powerpc/configs/ppc64_defconfig3
-rw-r--r--arch/powerpc/configs/pseries_defconfig3
-rw-r--r--arch/powerpc/kernel/entry_64.S60
-rw-r--r--arch/powerpc/kernel/process.c4
-rw-r--r--arch/powerpc/kernel/smp.c6
-rw-r--r--arch/powerpc/kernel/watchdog.c49
-rw-r--r--arch/powerpc/platforms/powernv/idle.c41
-rw-r--r--drivers/cpuidle/cpuidle-powernv.c10
9 files changed, 111 insertions, 68 deletions
diff --git a/arch/powerpc/configs/powernv_defconfig b/arch/powerpc/configs/powernv_defconfig
index 0695ce047d56..34fc9bbfca9e 100644
--- a/arch/powerpc/configs/powernv_defconfig
+++ b/arch/powerpc/configs/powernv_defconfig
@@ -293,7 +293,8 @@ CONFIG_MAGIC_SYSRQ=y
CONFIG_DEBUG_KERNEL=y
CONFIG_DEBUG_STACK_USAGE=y
CONFIG_DEBUG_STACKOVERFLOW=y
-CONFIG_LOCKUP_DETECTOR=y
+CONFIG_SOFTLOCKUP_DETECTOR=y
+CONFIG_HARDLOCKUP_DETECTOR=y
CONFIG_LATENCYTOP=y
CONFIG_SCHED_TRACER=y
CONFIG_BLK_DEV_IO_TRACE=y
diff --git a/arch/powerpc/configs/ppc64_defconfig b/arch/powerpc/configs/ppc64_defconfig
index 5175028c56ce..c5246d29f385 100644
--- a/arch/powerpc/configs/ppc64_defconfig
+++ b/arch/powerpc/configs/ppc64_defconfig
@@ -324,7 +324,8 @@ CONFIG_MAGIC_SYSRQ=y
CONFIG_DEBUG_KERNEL=y
CONFIG_DEBUG_STACK_USAGE=y
CONFIG_DEBUG_STACKOVERFLOW=y
-CONFIG_LOCKUP_DETECTOR=y
+CONFIG_SOFTLOCKUP_DETECTOR=y
+CONFIG_HARDLOCKUP_DETECTOR=y
CONFIG_DEBUG_MUTEXES=y
CONFIG_LATENCYTOP=y
CONFIG_SCHED_TRACER=y
diff --git a/arch/powerpc/configs/pseries_defconfig b/arch/powerpc/configs/pseries_defconfig
index 1a61aa20dfba..fd5d98a0b95c 100644
--- a/arch/powerpc/configs/pseries_defconfig
+++ b/arch/powerpc/configs/pseries_defconfig
@@ -291,7 +291,8 @@ CONFIG_MAGIC_SYSRQ=y
CONFIG_DEBUG_KERNEL=y
CONFIG_DEBUG_STACK_USAGE=y
CONFIG_DEBUG_STACKOVERFLOW=y
-CONFIG_LOCKUP_DETECTOR=y
+CONFIG_SOFTLOCKUP_DETECTOR=y
+CONFIG_HARDLOCKUP_DETECTOR=y
CONFIG_LATENCYTOP=y
CONFIG_SCHED_TRACER=y
CONFIG_BLK_DEV_IO_TRACE=y
diff --git a/arch/powerpc/kernel/entry_64.S b/arch/powerpc/kernel/entry_64.S
index 49d8422767b4..e925c1c99c71 100644
--- a/arch/powerpc/kernel/entry_64.S
+++ b/arch/powerpc/kernel/entry_64.S
@@ -223,17 +223,27 @@ system_call_exit:
andi. r0,r9,(_TIF_SYSCALL_DOTRACE|_TIF_SINGLESTEP|_TIF_USER_WORK_MASK|_TIF_PERSYSCALL_MASK)
bne- .Lsyscall_exit_work
- /* If MSR_FP and MSR_VEC are set in user msr, then no need to restore */
- li r7,MSR_FP
+ andi. r0,r8,MSR_FP
+ beq 2f
#ifdef CONFIG_ALTIVEC
- oris r7,r7,MSR_VEC@h
+ andis. r0,r8,MSR_VEC@h
+ bne 3f
#endif
- and r0,r8,r7
- cmpd r0,r7
- bne .Lsyscall_restore_math
-.Lsyscall_restore_math_cont:
+2: addi r3,r1,STACK_FRAME_OVERHEAD
+#ifdef CONFIG_PPC_BOOK3S
+ li r10,MSR_RI
+ mtmsrd r10,1 /* Restore RI */
+#endif
+ bl restore_math
+#ifdef CONFIG_PPC_BOOK3S
+ li r11,0
+ mtmsrd r11,1
+#endif
+ ld r8,_MSR(r1)
+ ld r3,RESULT(r1)
+ li r11,-MAX_ERRNO
- cmpld r3,r11
+3: cmpld r3,r11
ld r5,_CCR(r1)
bge- .Lsyscall_error
.Lsyscall_error_cont:
@@ -267,40 +277,6 @@ END_FTR_SECTION_IFSET(CPU_FTR_HAS_PPR)
std r5,_CCR(r1)
b .Lsyscall_error_cont
-.Lsyscall_restore_math:
- /*
- * Some initial tests from restore_math to avoid the heavyweight
- * C code entry and MSR manipulations.
- */
- LOAD_REG_IMMEDIATE(r0, MSR_TS_MASK)
- and. r0,r0,r8
- bne 1f
-
- ld r7,PACACURRENT(r13)
- lbz r0,THREAD+THREAD_LOAD_FP(r7)
-#ifdef CONFIG_ALTIVEC
- lbz r6,THREAD+THREAD_LOAD_VEC(r7)
- add r0,r0,r6
-#endif
- cmpdi r0,0
- beq .Lsyscall_restore_math_cont
-
-1: addi r3,r1,STACK_FRAME_OVERHEAD
-#ifdef CONFIG_PPC_BOOK3S
- li r10,MSR_RI
- mtmsrd r10,1 /* Restore RI */
-#endif
- bl restore_math
-#ifdef CONFIG_PPC_BOOK3S
- li r11,0
- mtmsrd r11,1
-#endif
- /* Restore volatiles, reload MSR from updated one */
- ld r8,_MSR(r1)
- ld r3,RESULT(r1)
- li r11,-MAX_ERRNO
- b .Lsyscall_restore_math_cont
-
/* Traced system call support */
.Lsyscall_dotrace:
bl save_nvgprs
diff --git a/arch/powerpc/kernel/process.c b/arch/powerpc/kernel/process.c
index 9f3e2c932dcc..ec480966f9bf 100644
--- a/arch/powerpc/kernel/process.c
+++ b/arch/powerpc/kernel/process.c
@@ -511,10 +511,6 @@ void restore_math(struct pt_regs *regs)
{
unsigned long msr;
- /*
- * Syscall exit makes a similar initial check before branching
- * to restore_math. Keep them in synch.
- */
if (!msr_tm_active(regs->msr) &&
!current->thread.load_fp && !loadvec(current->thread))
return;
diff --git a/arch/powerpc/kernel/smp.c b/arch/powerpc/kernel/smp.c
index cf0e1245b8cc..8d3320562c70 100644
--- a/arch/powerpc/kernel/smp.c
+++ b/arch/powerpc/kernel/smp.c
@@ -351,7 +351,7 @@ static void nmi_ipi_lock_start(unsigned long *flags)
hard_irq_disable();
while (atomic_cmpxchg(&__nmi_ipi_lock, 0, 1) == 1) {
raw_local_irq_restore(*flags);
- cpu_relax();
+ spin_until_cond(atomic_read(&__nmi_ipi_lock) == 0);
raw_local_irq_save(*flags);
hard_irq_disable();
}
@@ -360,7 +360,7 @@ static void nmi_ipi_lock_start(unsigned long *flags)
static void nmi_ipi_lock(void)
{
while (atomic_cmpxchg(&__nmi_ipi_lock, 0, 1) == 1)
- cpu_relax();
+ spin_until_cond(atomic_read(&__nmi_ipi_lock) == 0);
}
static void nmi_ipi_unlock(void)
@@ -475,7 +475,7 @@ int smp_send_nmi_ipi(int cpu, void (*fn)(struct pt_regs *), u64 delay_us)
nmi_ipi_lock_start(&flags);
while (nmi_ipi_busy_count) {
nmi_ipi_unlock_end(&flags);
- cpu_relax();
+ spin_until_cond(nmi_ipi_busy_count == 0);
nmi_ipi_lock_start(&flags);
}
diff --git a/arch/powerpc/kernel/watchdog.c b/arch/powerpc/kernel/watchdog.c
index b67f8b03a32d..34721a257a77 100644
--- a/arch/powerpc/kernel/watchdog.c
+++ b/arch/powerpc/kernel/watchdog.c
@@ -71,15 +71,20 @@ static inline void wd_smp_lock(unsigned long *flags)
* This may be called from low level interrupt handlers at some
* point in future.
*/
- local_irq_save(*flags);
- while (unlikely(test_and_set_bit_lock(0, &__wd_smp_lock)))
- cpu_relax();
+ raw_local_irq_save(*flags);
+ hard_irq_disable(); /* Make it soft-NMI safe */
+ while (unlikely(test_and_set_bit_lock(0, &__wd_smp_lock))) {
+ raw_local_irq_restore(*flags);
+ spin_until_cond(!test_bit(0, &__wd_smp_lock));
+ raw_local_irq_save(*flags);
+ hard_irq_disable();
+ }
}
static inline void wd_smp_unlock(unsigned long *flags)
{
clear_bit_unlock(0, &__wd_smp_lock);
- local_irq_restore(*flags);
+ raw_local_irq_restore(*flags);
}
static void wd_lockup_ipi(struct pt_regs *regs)
@@ -96,10 +101,10 @@ static void wd_lockup_ipi(struct pt_regs *regs)
nmi_panic(regs, "Hard LOCKUP");
}
-static void set_cpu_stuck(int cpu, u64 tb)
+static void set_cpumask_stuck(const struct cpumask *cpumask, u64 tb)
{
- cpumask_set_cpu(cpu, &wd_smp_cpus_stuck);
- cpumask_clear_cpu(cpu, &wd_smp_cpus_pending);
+ cpumask_or(&wd_smp_cpus_stuck, &wd_smp_cpus_stuck, cpumask);
+ cpumask_andnot(&wd_smp_cpus_pending, &wd_smp_cpus_pending, cpumask);
if (cpumask_empty(&wd_smp_cpus_pending)) {
wd_smp_last_reset_tb = tb;
cpumask_andnot(&wd_smp_cpus_pending,
@@ -107,6 +112,10 @@ static void set_cpu_stuck(int cpu, u64 tb)
&wd_smp_cpus_stuck);
}
}
+static void set_cpu_stuck(int cpu, u64 tb)
+{
+ set_cpumask_stuck(cpumask_of(cpu), tb);
+}
static void watchdog_smp_panic(int cpu, u64 tb)
{
@@ -135,11 +144,9 @@ static void watchdog_smp_panic(int cpu, u64 tb)
}
smp_flush_nmi_ipi(1000000);
- /* Take the stuck CPU out of the watch group */
- for_each_cpu(c, &wd_smp_cpus_pending)
- set_cpu_stuck(c, tb);
+ /* Take the stuck CPUs out of the watch group */
+ set_cpumask_stuck(&wd_smp_cpus_pending, tb);
-out:
wd_smp_unlock(&flags);
printk_safe_flush();
@@ -152,6 +159,11 @@ out:
if (hardlockup_panic)
nmi_panic(NULL, "Hard LOCKUP");
+
+ return;
+
+out:
+ wd_smp_unlock(&flags);
}
static void wd_smp_clear_cpu_pending(int cpu, u64 tb)
@@ -258,9 +270,11 @@ static void wd_timer_fn(unsigned long data)
void arch_touch_nmi_watchdog(void)
{
+ unsigned long ticks = tb_ticks_per_usec * wd_timer_period_ms * 1000;
int cpu = smp_processor_id();
- watchdog_timer_interrupt(cpu);
+ if (get_tb() - per_cpu(wd_timer_tb, cpu) >= ticks)
+ watchdog_timer_interrupt(cpu);
}
EXPORT_SYMBOL(arch_touch_nmi_watchdog);
@@ -283,6 +297,8 @@ static void stop_watchdog_timer_on(unsigned int cpu)
static int start_wd_on_cpu(unsigned int cpu)
{
+ unsigned long flags;
+
if (cpumask_test_cpu(cpu, &wd_cpus_enabled)) {
WARN_ON(1);
return 0;
@@ -297,12 +313,14 @@ static int start_wd_on_cpu(unsigned int cpu)
if (!cpumask_test_cpu(cpu, &watchdog_cpumask))
return 0;
+ wd_smp_lock(&flags);
cpumask_set_cpu(cpu, &wd_cpus_enabled);
if (cpumask_weight(&wd_cpus_enabled) == 1) {
cpumask_set_cpu(cpu, &wd_smp_cpus_pending);
wd_smp_last_reset_tb = get_tb();
}
- smp_wmb();
+ wd_smp_unlock(&flags);
+
start_watchdog_timer_on(cpu);
return 0;
@@ -310,12 +328,17 @@ static int start_wd_on_cpu(unsigned int cpu)
static int stop_wd_on_cpu(unsigned int cpu)
{
+ unsigned long flags;
+
if (!cpumask_test_cpu(cpu, &wd_cpus_enabled))
return 0; /* Can happen in CPU unplug case */
stop_watchdog_timer_on(cpu);
+ wd_smp_lock(&flags);
cpumask_clear_cpu(cpu, &wd_cpus_enabled);
+ wd_smp_unlock(&flags);
+
wd_smp_clear_cpu_pending(cpu, get_tb());
return 0;
diff --git a/arch/powerpc/platforms/powernv/idle.c b/arch/powerpc/platforms/powernv/idle.c
index 2abee070373f..a553aeea7af6 100644
--- a/arch/powerpc/platforms/powernv/idle.c
+++ b/arch/powerpc/platforms/powernv/idle.c
@@ -56,6 +56,7 @@ u64 pnv_first_deep_stop_state = MAX_STOP_STATE;
*/
static u64 pnv_deepest_stop_psscr_val;
static u64 pnv_deepest_stop_psscr_mask;
+static u64 pnv_deepest_stop_flag;
static bool deepest_stop_found;
static int pnv_save_sprs_for_deep_states(void)
@@ -185,8 +186,40 @@ static void pnv_alloc_idle_core_states(void)
update_subcore_sibling_mask();
- if (supported_cpuidle_states & OPAL_PM_LOSE_FULL_CONTEXT)
- pnv_save_sprs_for_deep_states();
+ if (supported_cpuidle_states & OPAL_PM_LOSE_FULL_CONTEXT) {
+ int rc = pnv_save_sprs_for_deep_states();
+
+ if (likely(!rc))
+ return;
+
+ /*
+ * The stop-api is unable to restore hypervisor
+ * resources on wakeup from platform idle states which
+ * lose full context. So disable such states.
+ */
+ supported_cpuidle_states &= ~OPAL_PM_LOSE_FULL_CONTEXT;
+ pr_warn("cpuidle-powernv: Disabling idle states that lose full context\n");
+ pr_warn("cpuidle-powernv: Idle power-savings, CPU-Hotplug affected\n");
+
+ if (cpu_has_feature(CPU_FTR_ARCH_300) &&
+ (pnv_deepest_stop_flag & OPAL_PM_LOSE_FULL_CONTEXT)) {
+ /*
+ * Use the default stop state for CPU-Hotplug
+ * if available.
+ */
+ if (default_stop_found) {
+ pnv_deepest_stop_psscr_val =
+ pnv_default_stop_val;
+ pnv_deepest_stop_psscr_mask =
+ pnv_default_stop_mask;
+ pr_warn("cpuidle-powernv: Offlined CPUs will stop with psscr = 0x%016llx\n",
+ pnv_deepest_stop_psscr_val);
+ } else { /* Fallback to snooze loop for CPU-Hotplug */
+ deepest_stop_found = false;
+ pr_warn("cpuidle-powernv: Offlined CPUs will busy wait\n");
+ }
+ }
+ }
}
u32 pnv_get_supported_cpuidle_states(void)
@@ -375,7 +408,8 @@ unsigned long pnv_cpu_offline(unsigned int cpu)
pnv_deepest_stop_psscr_val;
srr1 = power9_idle_stop(psscr);
- } else if (idle_states & OPAL_PM_WINKLE_ENABLED) {
+ } else if ((idle_states & OPAL_PM_WINKLE_ENABLED) &&
+ (idle_states & OPAL_PM_LOSE_FULL_CONTEXT)) {
srr1 = power7_idle_insn(PNV_THREAD_WINKLE);
} else if ((idle_states & OPAL_PM_SLEEP_ENABLED) ||
(idle_states & OPAL_PM_SLEEP_ENABLED_ER1)) {
@@ -553,6 +587,7 @@ static int __init pnv_power9_idle_init(struct device_node *np, u32 *flags,
max_residency_ns = residency_ns[i];
pnv_deepest_stop_psscr_val = psscr_val[i];
pnv_deepest_stop_psscr_mask = psscr_mask[i];
+ pnv_deepest_stop_flag = flags[i];
deepest_stop_found = true;
}
diff --git a/drivers/cpuidle/cpuidle-powernv.c b/drivers/cpuidle/cpuidle-powernv.c
index 37b0698b7193..42896a67aeae 100644
--- a/drivers/cpuidle/cpuidle-powernv.c
+++ b/drivers/cpuidle/cpuidle-powernv.c
@@ -235,6 +235,7 @@ static inline int validate_dt_prop_sizes(const char *prop1, int prop1_len,
return -1;
}
+extern u32 pnv_get_supported_cpuidle_states(void);
static int powernv_add_idle_states(void)
{
struct device_node *power_mgt;
@@ -248,6 +249,8 @@ static int powernv_add_idle_states(void)
const char *names[CPUIDLE_STATE_MAX];
u32 has_stop_states = 0;
int i, rc;
+ u32 supported_flags = pnv_get_supported_cpuidle_states();
+
/* Currently we have snooze statically defined */
@@ -362,6 +365,13 @@ static int powernv_add_idle_states(void)
for (i = 0; i < dt_idle_states; i++) {
unsigned int exit_latency, target_residency;
bool stops_timebase = false;
+
+ /*
+ * Skip the platform idle state whose flag isn't in
+ * the supported_cpuidle_states flag mask.
+ */
+ if ((flags[i] & supported_flags) != flags[i])
+ continue;
/*
* If an idle state has exit latency beyond
* POWERNV_THRESHOLD_LATENCY_NS then don't use it