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-rw-r--r--debian/patches-rt/0167-locking-rtmutex-Provide-rt_mutex_slowlock_locked.patch145
1 files changed, 145 insertions, 0 deletions
diff --git a/debian/patches-rt/0167-locking-rtmutex-Provide-rt_mutex_slowlock_locked.patch b/debian/patches-rt/0167-locking-rtmutex-Provide-rt_mutex_slowlock_locked.patch
new file mode 100644
index 000000000..125846fe5
--- /dev/null
+++ b/debian/patches-rt/0167-locking-rtmutex-Provide-rt_mutex_slowlock_locked.patch
@@ -0,0 +1,145 @@
+From dbd55916b6a3efb4b812322d7502b174b4cceb69 Mon Sep 17 00:00:00 2001
+From: Thomas Gleixner <tglx@linutronix.de>
+Date: Thu, 12 Oct 2017 16:14:22 +0200
+Subject: [PATCH 167/323] locking/rtmutex: Provide rt_mutex_slowlock_locked()
+Origin: https://www.kernel.org/pub/linux/kernel/projects/rt/5.10/older/patches-5.10.204-rt100.tar.xz
+
+This is the inner-part of rt_mutex_slowlock(), required for rwsem-rt.
+
+Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
+Signed-off-by: Sebastian Andrzej Siewior <bigeasy@linutronix.de>
+---
+ kernel/locking/rtmutex.c | 67 +++++++++++++++++++--------------
+ kernel/locking/rtmutex_common.h | 7 ++++
+ 2 files changed, 45 insertions(+), 29 deletions(-)
+
+diff --git a/kernel/locking/rtmutex.c b/kernel/locking/rtmutex.c
+index c3f3c23fefef..395a3e8b2463 100644
+--- a/kernel/locking/rtmutex.c
++++ b/kernel/locking/rtmutex.c
+@@ -1234,35 +1234,16 @@ static void rt_mutex_handle_deadlock(int res, int detect_deadlock,
+ }
+ }
+
+-/*
+- * Slow path lock function:
+- */
+-static int __sched
+-rt_mutex_slowlock(struct rt_mutex *lock, int state,
+- struct hrtimer_sleeper *timeout,
+- enum rtmutex_chainwalk chwalk)
++int __sched rt_mutex_slowlock_locked(struct rt_mutex *lock, int state,
++ struct hrtimer_sleeper *timeout,
++ enum rtmutex_chainwalk chwalk,
++ struct rt_mutex_waiter *waiter)
+ {
+- struct rt_mutex_waiter waiter;
+- unsigned long flags;
+- int ret = 0;
+-
+- rt_mutex_init_waiter(&waiter);
+-
+- /*
+- * Technically we could use raw_spin_[un]lock_irq() here, but this can
+- * be called in early boot if the cmpxchg() fast path is disabled
+- * (debug, no architecture support). In this case we will acquire the
+- * rtmutex with lock->wait_lock held. But we cannot unconditionally
+- * enable interrupts in that early boot case. So we need to use the
+- * irqsave/restore variants.
+- */
+- raw_spin_lock_irqsave(&lock->wait_lock, flags);
++ int ret;
+
+ /* Try to acquire the lock again: */
+- if (try_to_take_rt_mutex(lock, current, NULL)) {
+- raw_spin_unlock_irqrestore(&lock->wait_lock, flags);
++ if (try_to_take_rt_mutex(lock, current, NULL))
+ return 0;
+- }
+
+ set_current_state(state);
+
+@@ -1270,16 +1251,16 @@ rt_mutex_slowlock(struct rt_mutex *lock, int state,
+ if (unlikely(timeout))
+ hrtimer_start_expires(&timeout->timer, HRTIMER_MODE_ABS);
+
+- ret = task_blocks_on_rt_mutex(lock, &waiter, current, chwalk);
++ ret = task_blocks_on_rt_mutex(lock, waiter, current, chwalk);
+
+ if (likely(!ret))
+ /* sleep on the mutex */
+- ret = __rt_mutex_slowlock(lock, state, timeout, &waiter);
++ ret = __rt_mutex_slowlock(lock, state, timeout, waiter);
+
+ if (unlikely(ret)) {
+ __set_current_state(TASK_RUNNING);
+- remove_waiter(lock, &waiter);
+- rt_mutex_handle_deadlock(ret, chwalk, &waiter);
++ remove_waiter(lock, waiter);
++ rt_mutex_handle_deadlock(ret, chwalk, waiter);
+ }
+
+ /*
+@@ -1287,6 +1268,34 @@ rt_mutex_slowlock(struct rt_mutex *lock, int state,
+ * unconditionally. We might have to fix that up.
+ */
+ fixup_rt_mutex_waiters(lock);
++ return ret;
++}
++
++/*
++ * Slow path lock function:
++ */
++static int __sched
++rt_mutex_slowlock(struct rt_mutex *lock, int state,
++ struct hrtimer_sleeper *timeout,
++ enum rtmutex_chainwalk chwalk)
++{
++ struct rt_mutex_waiter waiter;
++ unsigned long flags;
++ int ret = 0;
++
++ rt_mutex_init_waiter(&waiter);
++
++ /*
++ * Technically we could use raw_spin_[un]lock_irq() here, but this can
++ * be called in early boot if the cmpxchg() fast path is disabled
++ * (debug, no architecture support). In this case we will acquire the
++ * rtmutex with lock->wait_lock held. But we cannot unconditionally
++ * enable interrupts in that early boot case. So we need to use the
++ * irqsave/restore variants.
++ */
++ raw_spin_lock_irqsave(&lock->wait_lock, flags);
++
++ ret = rt_mutex_slowlock_locked(lock, state, timeout, chwalk, &waiter);
+
+ raw_spin_unlock_irqrestore(&lock->wait_lock, flags);
+
+diff --git a/kernel/locking/rtmutex_common.h b/kernel/locking/rtmutex_common.h
+index 37cd6b3bf6f4..b5a2affa59d5 100644
+--- a/kernel/locking/rtmutex_common.h
++++ b/kernel/locking/rtmutex_common.h
+@@ -15,6 +15,7 @@
+
+ #include <linux/rtmutex.h>
+ #include <linux/sched/wake_q.h>
++#include <linux/sched/debug.h>
+
+ /*
+ * This is the control structure for tasks blocked on a rt_mutex,
+@@ -153,6 +154,12 @@ extern bool __rt_mutex_futex_unlock(struct rt_mutex *lock,
+ struct wake_q_head *wqh);
+
+ extern void rt_mutex_postunlock(struct wake_q_head *wake_q);
++/* RW semaphore special interface */
++
++int __sched rt_mutex_slowlock_locked(struct rt_mutex *lock, int state,
++ struct hrtimer_sleeper *timeout,
++ enum rtmutex_chainwalk chwalk,
++ struct rt_mutex_waiter *waiter);
+
+ #ifdef CONFIG_DEBUG_RT_MUTEXES
+ # include "rtmutex-debug.h"
+--
+2.43.0
+