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-rw-r--r--debian/patches-rt/0194-rt-Add-local-irq-locks.patch182
1 files changed, 182 insertions, 0 deletions
diff --git a/debian/patches-rt/0194-rt-Add-local-irq-locks.patch b/debian/patches-rt/0194-rt-Add-local-irq-locks.patch
new file mode 100644
index 000000000..53b3fd552
--- /dev/null
+++ b/debian/patches-rt/0194-rt-Add-local-irq-locks.patch
@@ -0,0 +1,182 @@
+From 0d3e0b0db513aac6e4cd2e2d084b7a76f4d28c44 Mon Sep 17 00:00:00 2001
+From: Thomas Gleixner <tglx@linutronix.de>
+Date: Mon, 20 Jun 2011 09:03:47 +0200
+Subject: [PATCH 194/323] rt: Add local irq locks
+Origin: https://www.kernel.org/pub/linux/kernel/projects/rt/5.10/older/patches-5.10.204-rt100.tar.xz
+
+Introduce locallock. For !RT this maps to preempt_disable()/
+local_irq_disable() so there is not much that changes. For RT this will
+map to a spinlock. This makes preemption possible and locked "ressource"
+gets the lockdep anotation it wouldn't have otherwise. The locks are
+recursive for owner == current. Also, all locks user migrate_disable()
+which ensures that the task is not migrated to another CPU while the lock
+is held and the owner is preempted.
+
+Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
+---
+ include/linux/local_lock_internal.h | 111 ++++++++++++++++++++++++++--
+ 1 file changed, 103 insertions(+), 8 deletions(-)
+
+diff --git a/include/linux/local_lock_internal.h b/include/linux/local_lock_internal.h
+index 3f02b818625e..1b8ae034946f 100644
+--- a/include/linux/local_lock_internal.h
++++ b/include/linux/local_lock_internal.h
+@@ -7,13 +7,39 @@
+ #include <linux/lockdep.h>
+
+ typedef struct {
+-#ifdef CONFIG_DEBUG_LOCK_ALLOC
++#ifdef CONFIG_PREEMPT_RT
++ spinlock_t lock;
++ struct task_struct *owner;
++ int nestcnt;
++
++#elif defined(CONFIG_DEBUG_LOCK_ALLOC)
+ struct lockdep_map dep_map;
+ struct task_struct *owner;
+ #endif
+ } local_lock_t;
+
+-#ifdef CONFIG_DEBUG_LOCK_ALLOC
++#ifdef CONFIG_PREEMPT_RT
++
++#define INIT_LOCAL_LOCK(lockname) { \
++ __SPIN_LOCK_UNLOCKED((lockname).lock), \
++ .owner = NULL, \
++ .nestcnt = 0, \
++ }
++
++static inline void ___local_lock_init(local_lock_t *l)
++{
++ l->owner = NULL;
++ l->nestcnt = 0;
++}
++
++#define __local_lock_init(l) \
++do { \
++ spin_lock_init(&(l)->lock); \
++ ___local_lock_init(l); \
++} while (0)
++
++#elif defined(CONFIG_DEBUG_LOCK_ALLOC)
++
+ # define LOCAL_LOCK_DEBUG_INIT(lockname) \
+ .dep_map = { \
+ .name = #lockname, \
+@@ -21,7 +47,33 @@ typedef struct {
+ .lock_type = LD_LOCK_PERCPU, \
+ }, \
+ .owner = NULL,
++#endif
++
++#ifdef CONFIG_PREEMPT_RT
+
++static inline void local_lock_acquire(local_lock_t *l)
++{
++ if (l->owner != current) {
++ spin_lock(&l->lock);
++ DEBUG_LOCKS_WARN_ON(l->owner);
++ DEBUG_LOCKS_WARN_ON(l->nestcnt);
++ l->owner = current;
++ }
++ l->nestcnt++;
++}
++
++static inline void local_lock_release(local_lock_t *l)
++{
++ DEBUG_LOCKS_WARN_ON(l->nestcnt == 0);
++ DEBUG_LOCKS_WARN_ON(l->owner != current);
++ if (--l->nestcnt)
++ return;
++
++ l->owner = NULL;
++ spin_unlock(&l->lock);
++}
++
++#elif defined(CONFIG_DEBUG_LOCK_ALLOC)
+ static inline void local_lock_acquire(local_lock_t *l)
+ {
+ lock_map_acquire(&l->dep_map);
+@@ -47,6 +99,47 @@ static inline void local_lock_release(local_lock_t *l) { }
+ static inline void local_lock_debug_init(local_lock_t *l) { }
+ #endif /* !CONFIG_DEBUG_LOCK_ALLOC */
+
++#ifdef CONFIG_PREEMPT_RT
++
++#define __local_lock(lock) \
++ do { \
++ migrate_disable(); \
++ local_lock_acquire(this_cpu_ptr(lock)); \
++ } while (0)
++
++#define __local_unlock(lock) \
++ do { \
++ local_lock_release(this_cpu_ptr(lock)); \
++ migrate_enable(); \
++ } while (0)
++
++#define __local_lock_irq(lock) \
++ do { \
++ migrate_disable(); \
++ local_lock_acquire(this_cpu_ptr(lock)); \
++ } while (0)
++
++#define __local_lock_irqsave(lock, flags) \
++ do { \
++ migrate_disable(); \
++ flags = 0; \
++ local_lock_acquire(this_cpu_ptr(lock)); \
++ } while (0)
++
++#define __local_unlock_irq(lock) \
++ do { \
++ local_lock_release(this_cpu_ptr(lock)); \
++ migrate_enable(); \
++ } while (0)
++
++#define __local_unlock_irqrestore(lock, flags) \
++ do { \
++ local_lock_release(this_cpu_ptr(lock)); \
++ migrate_enable(); \
++ } while (0)
++
++#else
++
+ #define INIT_LOCAL_LOCK(lockname) { LOCAL_LOCK_DEBUG_INIT(lockname) }
+
+ #define __local_lock_init(lock) \
+@@ -66,6 +159,12 @@ do { \
+ local_lock_acquire(this_cpu_ptr(lock)); \
+ } while (0)
+
++#define __local_unlock(lock) \
++ do { \
++ local_lock_release(this_cpu_ptr(lock)); \
++ preempt_enable(); \
++ } while (0)
++
+ #define __local_lock_irq(lock) \
+ do { \
+ local_irq_disable(); \
+@@ -78,12 +177,6 @@ do { \
+ local_lock_acquire(this_cpu_ptr(lock)); \
+ } while (0)
+
+-#define __local_unlock(lock) \
+- do { \
+- local_lock_release(this_cpu_ptr(lock)); \
+- preempt_enable(); \
+- } while (0)
+-
+ #define __local_unlock_irq(lock) \
+ do { \
+ local_lock_release(this_cpu_ptr(lock)); \
+@@ -95,3 +188,5 @@ do { \
+ local_lock_release(this_cpu_ptr(lock)); \
+ local_irq_restore(flags); \
+ } while (0)
++
++#endif
+--
+2.43.0
+