From 15ade055295d13f95d49e3d99b09f3bbfb4a43e7 Mon Sep 17 00:00:00 2001
From: hc <hc@nodka.com>
Date: Mon, 06 Nov 2023 07:25:24 +0000
Subject: [PATCH] add at24 driver
---
kernel/kernel/time/hrtimer.c | 126 +++++++++++++++++++++++++++++++++++++----
1 files changed, 112 insertions(+), 14 deletions(-)
diff --git a/kernel/kernel/time/hrtimer.c b/kernel/kernel/time/hrtimer.c
index 32ee24f..a846731 100644
--- a/kernel/kernel/time/hrtimer.c
+++ b/kernel/kernel/time/hrtimer.c
@@ -150,6 +150,11 @@
#define migration_base migration_cpu_base.clock_base[0]
+static inline bool is_migration_base(struct hrtimer_clock_base *base)
+{
+ return base == &migration_base;
+}
+
/*
* We are using hashed locking: holding per_cpu(hrtimer_bases)[n].lock
* means that all timers which are tied to this base via timer->base are
@@ -273,6 +278,11 @@
}
#else /* CONFIG_SMP */
+
+static inline bool is_migration_base(struct hrtimer_clock_base *base)
+{
+ return false;
+}
static inline struct hrtimer_clock_base *
lock_hrtimer_base(const struct hrtimer *timer, unsigned long *flags)
@@ -957,6 +967,16 @@
}
EXPORT_SYMBOL_GPL(hrtimer_forward);
+void hrtimer_grab_expiry_lock(const struct hrtimer *timer)
+{
+ struct hrtimer_clock_base *base = READ_ONCE(timer->base);
+
+ if (timer->is_soft && !is_migration_base(base)) {
+ spin_lock(&base->cpu_base->softirq_expiry_lock);
+ spin_unlock(&base->cpu_base->softirq_expiry_lock);
+ }
+}
+
/*
* enqueue_hrtimer - internal function to (re)start a timer
*
@@ -1175,7 +1195,9 @@
* Check whether the HRTIMER_MODE_SOFT bit and hrtimer.is_soft
* match.
*/
+#ifndef CONFIG_PREEMPT_RT_BASE
WARN_ON_ONCE(!(mode & HRTIMER_MODE_SOFT) ^ !timer->is_soft);
+#endif
base = lock_hrtimer_base(timer, &flags);
@@ -1238,7 +1260,7 @@
if (ret >= 0)
return ret;
- cpu_relax();
+ hrtimer_grab_expiry_lock(timer);
}
}
EXPORT_SYMBOL_GPL(hrtimer_cancel);
@@ -1335,9 +1357,16 @@
static void __hrtimer_init(struct hrtimer *timer, clockid_t clock_id,
enum hrtimer_mode mode)
{
- bool softtimer = !!(mode & HRTIMER_MODE_SOFT);
- int base = softtimer ? HRTIMER_MAX_CLOCK_BASES / 2 : 0;
+ bool softtimer;
+ int base;
struct hrtimer_cpu_base *cpu_base;
+
+ softtimer = !!(mode & HRTIMER_MODE_SOFT);
+#ifdef CONFIG_PREEMPT_RT_FULL
+ if (!softtimer && !(mode & HRTIMER_MODE_HARD))
+ softtimer = true;
+#endif
+ base = softtimer ? HRTIMER_MAX_CLOCK_BASES / 2 : 0;
memset(timer, 0, sizeof(struct hrtimer));
@@ -1535,6 +1564,7 @@
unsigned long flags;
ktime_t now;
+ spin_lock(&cpu_base->softirq_expiry_lock);
raw_spin_lock_irqsave(&cpu_base->lock, flags);
now = hrtimer_update_base(cpu_base);
@@ -1544,6 +1574,7 @@
hrtimer_update_softirq_timer(cpu_base, true);
raw_spin_unlock_irqrestore(&cpu_base->lock, flags);
+ spin_unlock(&cpu_base->softirq_expiry_lock);
}
#ifdef CONFIG_HIGH_RES_TIMERS
@@ -1715,12 +1746,51 @@
return HRTIMER_NORESTART;
}
-void hrtimer_init_sleeper(struct hrtimer_sleeper *sl, struct task_struct *task)
+static void __hrtimer_init_sleeper(struct hrtimer_sleeper *sl,
+ clockid_t clock_id,
+ enum hrtimer_mode mode,
+ struct task_struct *task)
{
+#ifdef CONFIG_PREEMPT_RT_FULL
+ if (!(mode & (HRTIMER_MODE_SOFT | HRTIMER_MODE_HARD))) {
+ if (task_is_realtime(current) || system_state != SYSTEM_RUNNING)
+ mode |= HRTIMER_MODE_HARD;
+ else
+ mode |= HRTIMER_MODE_SOFT;
+ }
+#endif
+ __hrtimer_init(&sl->timer, clock_id, mode);
sl->timer.function = hrtimer_wakeup;
sl->task = task;
}
+
+/**
+ * hrtimer_init_sleeper - initialize sleeper to the given clock
+ * @sl: sleeper to be initialized
+ * @clock_id: the clock to be used
+ * @mode: timer mode abs/rel
+ * @task: the task to wake up
+ */
+void hrtimer_init_sleeper(struct hrtimer_sleeper *sl, clockid_t clock_id,
+ enum hrtimer_mode mode, struct task_struct *task)
+{
+ debug_init(&sl->timer, clock_id, mode);
+ __hrtimer_init_sleeper(sl, clock_id, mode, task);
+
+}
EXPORT_SYMBOL_GPL(hrtimer_init_sleeper);
+
+#ifdef CONFIG_DEBUG_OBJECTS_TIMERS
+void hrtimer_init_sleeper_on_stack(struct hrtimer_sleeper *sl,
+ clockid_t clock_id,
+ enum hrtimer_mode mode,
+ struct task_struct *task)
+{
+ debug_object_init_on_stack(&sl->timer, &hrtimer_debug_descr);
+ __hrtimer_init_sleeper(sl, clock_id, mode, task);
+}
+EXPORT_SYMBOL_GPL(hrtimer_init_sleeper_on_stack);
+#endif
int nanosleep_copyout(struct restart_block *restart, struct timespec64 *ts)
{
@@ -1745,8 +1815,6 @@
{
struct restart_block *restart;
- hrtimer_init_sleeper(t, current);
-
do {
set_current_state(TASK_INTERRUPTIBLE);
hrtimer_start_expires(&t->timer, mode);
@@ -1754,12 +1822,12 @@
if (likely(t->task))
freezable_schedule();
+ __set_current_state(TASK_RUNNING);
hrtimer_cancel(&t->timer);
mode = HRTIMER_MODE_ABS;
} while (t->task && !signal_pending(current));
- __set_current_state(TASK_RUNNING);
if (!t->task)
return 0;
@@ -1783,10 +1851,9 @@
struct hrtimer_sleeper t;
int ret;
- hrtimer_init_on_stack(&t.timer, restart->nanosleep.clockid,
- HRTIMER_MODE_ABS);
+ hrtimer_init_sleeper_on_stack(&t, restart->nanosleep.clockid,
+ HRTIMER_MODE_ABS, current);
hrtimer_set_expires_tv64(&t.timer, restart->nanosleep.expires);
-
ret = do_nanosleep(&t, HRTIMER_MODE_ABS);
destroy_hrtimer_on_stack(&t.timer);
return ret;
@@ -1804,7 +1871,7 @@
if (dl_task(current) || rt_task(current))
slack = 0;
- hrtimer_init_on_stack(&t.timer, clockid, mode);
+ hrtimer_init_sleeper_on_stack(&t, clockid, mode, current);
hrtimer_set_expires_range_ns(&t.timer, timespec64_to_ktime(*rqtp), slack);
ret = do_nanosleep(&t, mode);
if (ret != -ERESTART_RESTARTBLOCK)
@@ -1864,6 +1931,38 @@
}
#endif
+#ifdef CONFIG_PREEMPT_RT_FULL
+/*
+ * Sleep for 1 ms in hope whoever holds what we want will let it go.
+ */
+void cpu_chill(void)
+{
+ unsigned int freeze_flag = current->flags & PF_NOFREEZE;
+ struct task_struct *self = current;
+ ktime_t chill_time;
+
+ raw_spin_lock_irq(&self->pi_lock);
+ self->saved_state = self->state;
+ __set_current_state_no_track(TASK_UNINTERRUPTIBLE);
+ raw_spin_unlock_irq(&self->pi_lock);
+
+ chill_time = ktime_set(0, NSEC_PER_MSEC);
+
+ current->flags |= PF_NOFREEZE;
+ sleeping_lock_inc();
+ schedule_hrtimeout(&chill_time, HRTIMER_MODE_REL_HARD);
+ sleeping_lock_dec();
+ if (!freeze_flag)
+ current->flags &= ~PF_NOFREEZE;
+
+ raw_spin_lock_irq(&self->pi_lock);
+ __set_current_state_no_track(self->saved_state);
+ self->saved_state = TASK_RUNNING;
+ raw_spin_unlock_irq(&self->pi_lock);
+}
+EXPORT_SYMBOL(cpu_chill);
+#endif
+
/*
* Functions related to boot-time initialization:
*/
@@ -1885,6 +1984,7 @@
cpu_base->softirq_next_timer = NULL;
cpu_base->expires_next = KTIME_MAX;
cpu_base->softirq_expires_next = KTIME_MAX;
+ spin_lock_init(&cpu_base->softirq_expiry_lock);
return 0;
}
@@ -2003,10 +2103,8 @@
return -EINTR;
}
- hrtimer_init_on_stack(&t.timer, clock_id, mode);
+ hrtimer_init_sleeper_on_stack(&t, clock_id, mode, current);
hrtimer_set_expires_range_ns(&t.timer, *expires, delta);
-
- hrtimer_init_sleeper(&t, current);
hrtimer_start_expires(&t.timer, mode);
--
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