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-rw-r--r--kernel/rcu/tree.c56
-rw-r--r--kernel/rcu/tree_plugin.h14
2 files changed, 38 insertions, 32 deletions
diff --git a/kernel/rcu/tree.c b/kernel/rcu/tree.c
index 8a62cbfe1f2f..3decfbc88308 100644
--- a/kernel/rcu/tree.c
+++ b/kernel/rcu/tree.c
@@ -57,6 +57,8 @@
#include <linux/trace_events.h>
#include <linux/suspend.h>
+#include <soc/qcom/watchdog.h>
+
#include "tree.h"
#include "rcu.h"
@@ -246,24 +248,17 @@ static int rcu_gp_in_progress(struct rcu_state *rsp)
*/
void rcu_sched_qs(void)
{
- unsigned long flags;
-
- if (__this_cpu_read(rcu_sched_data.cpu_no_qs.s)) {
- trace_rcu_grace_period(TPS("rcu_sched"),
- __this_cpu_read(rcu_sched_data.gpnum),
- TPS("cpuqs"));
- __this_cpu_write(rcu_sched_data.cpu_no_qs.b.norm, false);
- if (!__this_cpu_read(rcu_sched_data.cpu_no_qs.b.exp))
- return;
- local_irq_save(flags);
- if (__this_cpu_read(rcu_sched_data.cpu_no_qs.b.exp)) {
- __this_cpu_write(rcu_sched_data.cpu_no_qs.b.exp, false);
- rcu_report_exp_rdp(&rcu_sched_state,
- this_cpu_ptr(&rcu_sched_data),
- true);
- }
- local_irq_restore(flags);
- }
+ if (!__this_cpu_read(rcu_sched_data.cpu_no_qs.s))
+ return;
+ trace_rcu_grace_period(TPS("rcu_sched"),
+ __this_cpu_read(rcu_sched_data.gpnum),
+ TPS("cpuqs"));
+ __this_cpu_write(rcu_sched_data.cpu_no_qs.b.norm, false);
+ if (!__this_cpu_read(rcu_sched_data.cpu_no_qs.b.exp))
+ return;
+ __this_cpu_write(rcu_sched_data.cpu_no_qs.b.exp, false);
+ rcu_report_exp_rdp(&rcu_sched_state,
+ this_cpu_ptr(&rcu_sched_data), true);
}
void rcu_bh_qs(void)
@@ -300,17 +295,16 @@ EXPORT_PER_CPU_SYMBOL_GPL(rcu_qs_ctr);
* We inform the RCU core by emulating a zero-duration dyntick-idle
* period, which we in turn do by incrementing the ->dynticks counter
* by two.
+ *
+ * The caller must have disabled interrupts.
*/
static void rcu_momentary_dyntick_idle(void)
{
- unsigned long flags;
struct rcu_data *rdp;
struct rcu_dynticks *rdtp;
int resched_mask;
struct rcu_state *rsp;
- local_irq_save(flags);
-
/*
* Yes, we can lose flag-setting operations. This is OK, because
* the flag will be set again after some delay.
@@ -340,13 +334,12 @@ static void rcu_momentary_dyntick_idle(void)
smp_mb__after_atomic(); /* Later stuff after QS. */
break;
}
- local_irq_restore(flags);
}
/*
* Note a context switch. This is a quiescent state for RCU-sched,
* and requires special handling for preemptible RCU.
- * The caller must have disabled preemption.
+ * The caller must have disabled interrupts.
*/
void rcu_note_context_switch(void)
{
@@ -376,9 +369,14 @@ EXPORT_SYMBOL_GPL(rcu_note_context_switch);
*/
void rcu_all_qs(void)
{
+ unsigned long flags;
+
barrier(); /* Avoid RCU read-side critical sections leaking down. */
- if (unlikely(raw_cpu_read(rcu_sched_qs_mask)))
+ if (unlikely(raw_cpu_read(rcu_sched_qs_mask))) {
+ local_irq_save(flags);
rcu_momentary_dyntick_idle();
+ local_irq_restore(flags);
+ }
this_cpu_inc(rcu_qs_ctr);
barrier(); /* Avoid RCU read-side critical sections leaking up. */
}
@@ -1310,6 +1308,11 @@ static void print_other_cpu_stall(struct rcu_state *rsp, unsigned long gpnum)
rcu_check_gp_kthread_starvation(rsp);
+#ifdef CONFIG_RCU_STALL_WATCHDOG_BITE
+ /* Induce watchdog bite */
+ msm_trigger_wdog_bite();
+#endif
+
force_quiescent_state(rsp); /* Kick them all. */
}
@@ -1345,6 +1348,11 @@ static void print_cpu_stall(struct rcu_state *rsp)
jiffies + 3 * rcu_jiffies_till_stall_check() + 3);
raw_spin_unlock_irqrestore(&rnp->lock, flags);
+#ifdef CONFIG_RCU_STALL_WATCHDOG_BITE
+ /* Induce non secure watchdog bite to collect context */
+ msm_trigger_wdog_bite();
+#endif
+
/*
* Attempt to revive the RCU machinery by forcing a context switch.
*
diff --git a/kernel/rcu/tree_plugin.h b/kernel/rcu/tree_plugin.h
index 32cbe72bf545..c6fc11d626f8 100644
--- a/kernel/rcu/tree_plugin.h
+++ b/kernel/rcu/tree_plugin.h
@@ -147,8 +147,8 @@ static void __init rcu_bootup_announce(void)
* the corresponding expedited grace period will also be the end of the
* normal grace period.
*/
-static void rcu_preempt_ctxt_queue(struct rcu_node *rnp, struct rcu_data *rdp,
- unsigned long flags) __releases(rnp->lock)
+static void rcu_preempt_ctxt_queue(struct rcu_node *rnp, struct rcu_data *rdp)
+ __releases(rnp->lock) /* But leaves rrupts disabled. */
{
int blkd_state = (rnp->gp_tasks ? RCU_GP_TASKS : 0) +
(rnp->exp_tasks ? RCU_EXP_TASKS : 0) +
@@ -236,7 +236,7 @@ static void rcu_preempt_ctxt_queue(struct rcu_node *rnp, struct rcu_data *rdp,
rnp->gp_tasks = &t->rcu_node_entry;
if (!rnp->exp_tasks && (blkd_state & RCU_EXP_BLKD))
rnp->exp_tasks = &t->rcu_node_entry;
- raw_spin_unlock(&rnp->lock);
+ raw_spin_unlock(&rnp->lock); /* rrupts remain disabled. */
/*
* Report the quiescent state for the expedited GP. This expedited
@@ -251,7 +251,6 @@ static void rcu_preempt_ctxt_queue(struct rcu_node *rnp, struct rcu_data *rdp,
} else {
WARN_ON_ONCE(t->rcu_read_unlock_special.b.exp_need_qs);
}
- local_irq_restore(flags);
}
/*
@@ -286,12 +285,11 @@ static void rcu_preempt_qs(void)
* predating the current grace period drain, in other words, until
* rnp->gp_tasks becomes NULL.
*
- * Caller must disable preemption.
+ * Caller must disable interrupts.
*/
static void rcu_preempt_note_context_switch(void)
{
struct task_struct *t = current;
- unsigned long flags;
struct rcu_data *rdp;
struct rcu_node *rnp;
@@ -301,7 +299,7 @@ static void rcu_preempt_note_context_switch(void)
/* Possibly blocking in an RCU read-side critical section. */
rdp = this_cpu_ptr(rcu_state_p->rda);
rnp = rdp->mynode;
- raw_spin_lock_irqsave(&rnp->lock, flags);
+ raw_spin_lock(&rnp->lock);
smp_mb__after_unlock_lock();
t->rcu_read_unlock_special.b.blocked = true;
t->rcu_blocked_node = rnp;
@@ -318,7 +316,7 @@ static void rcu_preempt_note_context_switch(void)
(rnp->qsmask & rdp->grpmask)
? rnp->gpnum
: rnp->gpnum + 1);
- rcu_preempt_ctxt_queue(rnp, rdp, flags);
+ rcu_preempt_ctxt_queue(rnp, rdp);
} else if (t->rcu_read_lock_nesting < 0 &&
t->rcu_read_unlock_special.s) {