From e3e12f52b214121840b44c91de5b3e5af5d3eb84 Mon Sep 17 00:00:00 2001
From: hc <hc@nodka.com>
Date: Mon, 06 Nov 2023 03:04:41 +0000
Subject: [PATCH] rk3568 rt init
---
kernel/kernel/time/posix-cpu-timers.c | 181 ++++++++++++++++++++++++++++++++++++++++++++-
1 files changed, 177 insertions(+), 4 deletions(-)
diff --git a/kernel/kernel/time/posix-cpu-timers.c b/kernel/kernel/time/posix-cpu-timers.c
index bfaa44a..b9e4ccb 100644
--- a/kernel/kernel/time/posix-cpu-timers.c
+++ b/kernel/kernel/time/posix-cpu-timers.c
@@ -3,8 +3,10 @@
* Implement CPU time clocks for the POSIX clock interface.
*/
+#include <uapi/linux/sched/types.h>
#include <linux/sched/signal.h>
#include <linux/sched/cputime.h>
+#include <linux/sched/rt.h>
#include <linux/posix-timers.h>
#include <linux/errno.h>
#include <linux/math64.h>
@@ -15,6 +17,7 @@
#include <linux/workqueue.h>
#include <linux/compat.h>
#include <linux/sched/deadline.h>
+#include <linux/smpboot.h>
#include "posix-timers.h"
@@ -789,6 +792,7 @@
return t->expires;
t->firing = 1;
+ t->firing_cpu = smp_processor_id();
list_move_tail(&t->entry, firing);
}
@@ -1135,18 +1139,31 @@
return 0;
}
+static DEFINE_PER_CPU(spinlock_t, cpu_timer_expiry_lock) = __SPIN_LOCK_UNLOCKED(cpu_timer_expiry_lock);
+
+void cpu_timers_grab_expiry_lock(struct k_itimer *timer)
+{
+ int cpu = timer->it.cpu.firing_cpu;
+
+ if (cpu >= 0) {
+ spinlock_t *expiry_lock = per_cpu_ptr(&cpu_timer_expiry_lock, cpu);
+
+ spin_lock_irq(expiry_lock);
+ spin_unlock_irq(expiry_lock);
+ }
+}
+
/*
* This is called from the timer interrupt handler. The irq handler has
* already updated our counts. We need to check if any timers fire now.
* Interrupts are disabled.
*/
-void run_posix_cpu_timers(struct task_struct *tsk)
+static void __run_posix_cpu_timers(struct task_struct *tsk)
{
LIST_HEAD(firing);
struct k_itimer *timer, *next;
unsigned long flags;
-
- lockdep_assert_irqs_disabled();
+ spinlock_t *expiry_lock;
/*
* The fast path checks that there are no expired thread or thread
@@ -1155,8 +1172,13 @@
if (!fastpath_timer_check(tsk))
return;
- if (!lock_task_sighand(tsk, &flags))
+ expiry_lock = this_cpu_ptr(&cpu_timer_expiry_lock);
+ spin_lock(expiry_lock);
+
+ if (!lock_task_sighand(tsk, &flags)) {
+ spin_unlock(expiry_lock);
return;
+ }
/*
* Here we take off tsk->signal->cpu_timers[N] and
* tsk->cpu_timers[N] all the timers that are firing, and
@@ -1189,6 +1211,7 @@
list_del_init(&timer->it.cpu.entry);
cpu_firing = timer->it.cpu.firing;
timer->it.cpu.firing = 0;
+ timer->it.cpu.firing_cpu = -1;
/*
* The firing flag is -1 if we collided with a reset
* of the timer, which already reported this
@@ -1198,7 +1221,155 @@
cpu_timer_fire(timer);
spin_unlock(&timer->it_lock);
}
+ spin_unlock(expiry_lock);
}
+
+#ifdef CONFIG_PREEMPT_RT_BASE
+#include <linux/kthread.h>
+#include <linux/cpu.h>
+DEFINE_PER_CPU(struct task_struct *, posix_timer_task);
+DEFINE_PER_CPU(struct task_struct *, posix_timer_tasklist);
+DEFINE_PER_CPU(bool, posix_timer_th_active);
+
+static void posix_cpu_kthread_fn(unsigned int cpu)
+{
+ struct task_struct *tsk = NULL;
+ struct task_struct *next = NULL;
+
+ BUG_ON(per_cpu(posix_timer_task, cpu) != current);
+
+ /* grab task list */
+ raw_local_irq_disable();
+ tsk = per_cpu(posix_timer_tasklist, cpu);
+ per_cpu(posix_timer_tasklist, cpu) = NULL;
+ raw_local_irq_enable();
+
+ /* its possible the list is empty, just return */
+ if (!tsk)
+ return;
+
+ /* Process task list */
+ while (1) {
+ /* save next */
+ next = tsk->posix_timer_list;
+
+ /* run the task timers, clear its ptr and
+ * unreference it
+ */
+ __run_posix_cpu_timers(tsk);
+ tsk->posix_timer_list = NULL;
+ put_task_struct(tsk);
+
+ /* check if this is the last on the list */
+ if (next == tsk)
+ break;
+ tsk = next;
+ }
+}
+
+static inline int __fastpath_timer_check(struct task_struct *tsk)
+{
+ /* tsk == current, ensure it is safe to use ->signal/sighand */
+ if (unlikely(tsk->exit_state))
+ return 0;
+
+ if (!task_cputime_zero(&tsk->cputime_expires))
+ return 1;
+
+ if (!task_cputime_zero(&tsk->signal->cputime_expires))
+ return 1;
+
+ return 0;
+}
+
+void run_posix_cpu_timers(struct task_struct *tsk)
+{
+ unsigned int cpu = smp_processor_id();
+ struct task_struct *tasklist;
+
+ BUG_ON(!irqs_disabled());
+
+ if (per_cpu(posix_timer_th_active, cpu) != true)
+ return;
+
+ /* get per-cpu references */
+ tasklist = per_cpu(posix_timer_tasklist, cpu);
+
+ /* check to see if we're already queued */
+ if (!tsk->posix_timer_list && __fastpath_timer_check(tsk)) {
+ get_task_struct(tsk);
+ if (tasklist) {
+ tsk->posix_timer_list = tasklist;
+ } else {
+ /*
+ * The list is terminated by a self-pointing
+ * task_struct
+ */
+ tsk->posix_timer_list = tsk;
+ }
+ per_cpu(posix_timer_tasklist, cpu) = tsk;
+
+ wake_up_process(per_cpu(posix_timer_task, cpu));
+ }
+}
+
+static int posix_cpu_kthread_should_run(unsigned int cpu)
+{
+ return __this_cpu_read(posix_timer_tasklist) != NULL;
+}
+
+static void posix_cpu_kthread_park(unsigned int cpu)
+{
+ this_cpu_write(posix_timer_th_active, false);
+}
+
+static void posix_cpu_kthread_unpark(unsigned int cpu)
+{
+ this_cpu_write(posix_timer_th_active, true);
+}
+
+static void posix_cpu_kthread_setup(unsigned int cpu)
+{
+ struct sched_param sp;
+
+ sp.sched_priority = MAX_RT_PRIO - 1;
+ sched_setscheduler_nocheck(current, SCHED_FIFO, &sp);
+ posix_cpu_kthread_unpark(cpu);
+}
+
+static struct smp_hotplug_thread posix_cpu_thread = {
+ .store = &posix_timer_task,
+ .thread_should_run = posix_cpu_kthread_should_run,
+ .thread_fn = posix_cpu_kthread_fn,
+ .thread_comm = "posixcputmr/%u",
+ .setup = posix_cpu_kthread_setup,
+ .park = posix_cpu_kthread_park,
+ .unpark = posix_cpu_kthread_unpark,
+};
+
+static int __init posix_cpu_thread_init(void)
+{
+ /* Start one for boot CPU. */
+ unsigned long cpu;
+ int ret;
+
+ /* init the per-cpu posix_timer_tasklets */
+ for_each_possible_cpu(cpu)
+ per_cpu(posix_timer_tasklist, cpu) = NULL;
+
+ ret = smpboot_register_percpu_thread(&posix_cpu_thread);
+ WARN_ON(ret);
+
+ return 0;
+}
+early_initcall(posix_cpu_thread_init);
+#else /* CONFIG_PREEMPT_RT_BASE */
+void run_posix_cpu_timers(struct task_struct *tsk)
+{
+ lockdep_assert_irqs_disabled();
+ __run_posix_cpu_timers(tsk);
+}
+#endif /* CONFIG_PREEMPT_RT_BASE */
/*
* Set one of the process-wide special case CPU timers or RLIMIT_CPU.
@@ -1318,6 +1489,8 @@
spin_unlock_irq(&timer.it_lock);
while (error == TIMER_RETRY) {
+
+ cpu_timers_grab_expiry_lock(&timer);
/*
* We need to handle case when timer was or is in the
* middle of firing. In other cases we already freed
--
Gitblit v1.6.2