ifeq ($(CONFIG_COMPAT),y)
obj-$(CONFIG_FUTEX) += futex_compat.o
endif
-obj-$(CONFIG_RT_MUTEXES) += rtmutex.o
-obj-$(CONFIG_DEBUG_RT_MUTEXES) += rtmutex-debug.o
-obj-$(CONFIG_RT_MUTEX_TESTER) += rtmutex-tester.o
obj-$(CONFIG_GENERIC_ISA_DMA) += dma.o
obj-$(CONFIG_SMP) += smp.o
ifneq ($(CONFIG_SMP),y)
#include <asm/futex.h>
-#include "rtmutex_common.h"
+#include "locking/rtmutex_common.h"
int __read_mostly futex_cmpxchg_enabled;
endif
obj-$(CONFIG_SMP) += spinlock.o
obj-$(CONFIG_PROVE_LOCKING) += spinlock.o
+obj-$(CONFIG_RT_MUTEXES) += rtmutex.o
+obj-$(CONFIG_DEBUG_RT_MUTEXES) += rtmutex-debug.o
+obj-$(CONFIG_RT_MUTEX_TESTER) += rtmutex-tester.o
obj-$(CONFIG_DEBUG_SPINLOCK) += spinlock.o
obj-$(CONFIG_DEBUG_SPINLOCK) += spinlock_debug.o
--- /dev/null
+/*
+ * RT-Mutexes: blocking mutual exclusion locks with PI support
+ *
+ * started by Ingo Molnar and Thomas Gleixner:
+ *
+ * Copyright (C) 2004-2006 Red Hat, Inc., Ingo Molnar <mingo@redhat.com>
+ * Copyright (C) 2006 Timesys Corp., Thomas Gleixner <tglx@timesys.com>
+ *
+ * This code is based on the rt.c implementation in the preempt-rt tree.
+ * Portions of said code are
+ *
+ * Copyright (C) 2004 LynuxWorks, Inc., Igor Manyilov, Bill Huey
+ * Copyright (C) 2006 Esben Nielsen
+ * Copyright (C) 2006 Kihon Technologies Inc.,
+ * Steven Rostedt <rostedt@goodmis.org>
+ *
+ * See rt.c in preempt-rt for proper credits and further information
+ */
+#include <linux/sched.h>
+#include <linux/sched/rt.h>
+#include <linux/delay.h>
+#include <linux/export.h>
+#include <linux/spinlock.h>
+#include <linux/kallsyms.h>
+#include <linux/syscalls.h>
+#include <linux/interrupt.h>
+#include <linux/plist.h>
+#include <linux/fs.h>
+#include <linux/debug_locks.h>
+
+#include "rtmutex_common.h"
+
+static void printk_task(struct task_struct *p)
+{
+ if (p)
+ printk("%16s:%5d [%p, %3d]", p->comm, task_pid_nr(p), p, p->prio);
+ else
+ printk("<none>");
+}
+
+static void printk_lock(struct rt_mutex *lock, int print_owner)
+{
+ if (lock->name)
+ printk(" [%p] {%s}\n",
+ lock, lock->name);
+ else
+ printk(" [%p] {%s:%d}\n",
+ lock, lock->file, lock->line);
+
+ if (print_owner && rt_mutex_owner(lock)) {
+ printk(".. ->owner: %p\n", lock->owner);
+ printk(".. held by: ");
+ printk_task(rt_mutex_owner(lock));
+ printk("\n");
+ }
+}
+
+void rt_mutex_debug_task_free(struct task_struct *task)
+{
+ DEBUG_LOCKS_WARN_ON(!plist_head_empty(&task->pi_waiters));
+ DEBUG_LOCKS_WARN_ON(task->pi_blocked_on);
+}
+
+/*
+ * We fill out the fields in the waiter to store the information about
+ * the deadlock. We print when we return. act_waiter can be NULL in
+ * case of a remove waiter operation.
+ */
+void debug_rt_mutex_deadlock(int detect, struct rt_mutex_waiter *act_waiter,
+ struct rt_mutex *lock)
+{
+ struct task_struct *task;
+
+ if (!debug_locks || detect || !act_waiter)
+ return;
+
+ task = rt_mutex_owner(act_waiter->lock);
+ if (task && task != current) {
+ act_waiter->deadlock_task_pid = get_pid(task_pid(task));
+ act_waiter->deadlock_lock = lock;
+ }
+}
+
+void debug_rt_mutex_print_deadlock(struct rt_mutex_waiter *waiter)
+{
+ struct task_struct *task;
+
+ if (!waiter->deadlock_lock || !debug_locks)
+ return;
+
+ rcu_read_lock();
+ task = pid_task(waiter->deadlock_task_pid, PIDTYPE_PID);
+ if (!task) {
+ rcu_read_unlock();
+ return;
+ }
+
+ if (!debug_locks_off()) {
+ rcu_read_unlock();
+ return;
+ }
+
+ printk("\n============================================\n");
+ printk( "[ BUG: circular locking deadlock detected! ]\n");
+ printk("%s\n", print_tainted());
+ printk( "--------------------------------------------\n");
+ printk("%s/%d is deadlocking current task %s/%d\n\n",
+ task->comm, task_pid_nr(task),
+ current->comm, task_pid_nr(current));
+
+ printk("\n1) %s/%d is trying to acquire this lock:\n",
+ current->comm, task_pid_nr(current));
+ printk_lock(waiter->lock, 1);
+
+ printk("\n2) %s/%d is blocked on this lock:\n",
+ task->comm, task_pid_nr(task));
+ printk_lock(waiter->deadlock_lock, 1);
+
+ debug_show_held_locks(current);
+ debug_show_held_locks(task);
+
+ printk("\n%s/%d's [blocked] stackdump:\n\n",
+ task->comm, task_pid_nr(task));
+ show_stack(task, NULL);
+ printk("\n%s/%d's [current] stackdump:\n\n",
+ current->comm, task_pid_nr(current));
+ dump_stack();
+ debug_show_all_locks();
+ rcu_read_unlock();
+
+ printk("[ turning off deadlock detection."
+ "Please report this trace. ]\n\n");
+}
+
+void debug_rt_mutex_lock(struct rt_mutex *lock)
+{
+}
+
+void debug_rt_mutex_unlock(struct rt_mutex *lock)
+{
+ DEBUG_LOCKS_WARN_ON(rt_mutex_owner(lock) != current);
+}
+
+void
+debug_rt_mutex_proxy_lock(struct rt_mutex *lock, struct task_struct *powner)
+{
+}
+
+void debug_rt_mutex_proxy_unlock(struct rt_mutex *lock)
+{
+ DEBUG_LOCKS_WARN_ON(!rt_mutex_owner(lock));
+}
+
+void debug_rt_mutex_init_waiter(struct rt_mutex_waiter *waiter)
+{
+ memset(waiter, 0x11, sizeof(*waiter));
+ plist_node_init(&waiter->list_entry, MAX_PRIO);
+ plist_node_init(&waiter->pi_list_entry, MAX_PRIO);
+ waiter->deadlock_task_pid = NULL;
+}
+
+void debug_rt_mutex_free_waiter(struct rt_mutex_waiter *waiter)
+{
+ put_pid(waiter->deadlock_task_pid);
+ DEBUG_LOCKS_WARN_ON(!plist_node_empty(&waiter->list_entry));
+ DEBUG_LOCKS_WARN_ON(!plist_node_empty(&waiter->pi_list_entry));
+ memset(waiter, 0x22, sizeof(*waiter));
+}
+
+void debug_rt_mutex_init(struct rt_mutex *lock, const char *name)
+{
+ /*
+ * Make sure we are not reinitializing a held lock:
+ */
+ debug_check_no_locks_freed((void *)lock, sizeof(*lock));
+ lock->name = name;
+}
+
+void
+rt_mutex_deadlock_account_lock(struct rt_mutex *lock, struct task_struct *task)
+{
+}
+
+void rt_mutex_deadlock_account_unlock(struct task_struct *task)
+{
+}
+
--- /dev/null
+/*
+ * RT-Mutexes: blocking mutual exclusion locks with PI support
+ *
+ * started by Ingo Molnar and Thomas Gleixner:
+ *
+ * Copyright (C) 2004-2006 Red Hat, Inc., Ingo Molnar <mingo@redhat.com>
+ * Copyright (C) 2006, Timesys Corp., Thomas Gleixner <tglx@timesys.com>
+ *
+ * This file contains macros used solely by rtmutex.c. Debug version.
+ */
+
+extern void
+rt_mutex_deadlock_account_lock(struct rt_mutex *lock, struct task_struct *task);
+extern void rt_mutex_deadlock_account_unlock(struct task_struct *task);
+extern void debug_rt_mutex_init_waiter(struct rt_mutex_waiter *waiter);
+extern void debug_rt_mutex_free_waiter(struct rt_mutex_waiter *waiter);
+extern void debug_rt_mutex_init(struct rt_mutex *lock, const char *name);
+extern void debug_rt_mutex_lock(struct rt_mutex *lock);
+extern void debug_rt_mutex_unlock(struct rt_mutex *lock);
+extern void debug_rt_mutex_proxy_lock(struct rt_mutex *lock,
+ struct task_struct *powner);
+extern void debug_rt_mutex_proxy_unlock(struct rt_mutex *lock);
+extern void debug_rt_mutex_deadlock(int detect, struct rt_mutex_waiter *waiter,
+ struct rt_mutex *lock);
+extern void debug_rt_mutex_print_deadlock(struct rt_mutex_waiter *waiter);
+# define debug_rt_mutex_reset_waiter(w) \
+ do { (w)->deadlock_lock = NULL; } while (0)
+
+static inline int debug_rt_mutex_detect_deadlock(struct rt_mutex_waiter *waiter,
+ int detect)
+{
+ return (waiter != NULL);
+}
--- /dev/null
+/*
+ * RT-Mutex-tester: scriptable tester for rt mutexes
+ *
+ * started by Thomas Gleixner:
+ *
+ * Copyright (C) 2006, Timesys Corp., Thomas Gleixner <tglx@timesys.com>
+ *
+ */
+#include <linux/device.h>
+#include <linux/kthread.h>
+#include <linux/export.h>
+#include <linux/sched.h>
+#include <linux/sched/rt.h>
+#include <linux/spinlock.h>
+#include <linux/timer.h>
+#include <linux/freezer.h>
+#include <linux/stat.h>
+
+#include "rtmutex.h"
+
+#define MAX_RT_TEST_THREADS 8
+#define MAX_RT_TEST_MUTEXES 8
+
+static spinlock_t rttest_lock;
+static atomic_t rttest_event;
+
+struct test_thread_data {
+ int opcode;
+ int opdata;
+ int mutexes[MAX_RT_TEST_MUTEXES];
+ int event;
+ struct device dev;
+};
+
+static struct test_thread_data thread_data[MAX_RT_TEST_THREADS];
+static struct task_struct *threads[MAX_RT_TEST_THREADS];
+static struct rt_mutex mutexes[MAX_RT_TEST_MUTEXES];
+
+enum test_opcodes {
+ RTTEST_NOP = 0,
+ RTTEST_SCHEDOT, /* 1 Sched other, data = nice */
+ RTTEST_SCHEDRT, /* 2 Sched fifo, data = prio */
+ RTTEST_LOCK, /* 3 Lock uninterruptible, data = lockindex */
+ RTTEST_LOCKNOWAIT, /* 4 Lock uninterruptible no wait in wakeup, data = lockindex */
+ RTTEST_LOCKINT, /* 5 Lock interruptible, data = lockindex */
+ RTTEST_LOCKINTNOWAIT, /* 6 Lock interruptible no wait in wakeup, data = lockindex */
+ RTTEST_LOCKCONT, /* 7 Continue locking after the wakeup delay */
+ RTTEST_UNLOCK, /* 8 Unlock, data = lockindex */
+ /* 9, 10 - reserved for BKL commemoration */
+ RTTEST_SIGNAL = 11, /* 11 Signal other test thread, data = thread id */
+ RTTEST_RESETEVENT = 98, /* 98 Reset event counter */
+ RTTEST_RESET = 99, /* 99 Reset all pending operations */
+};
+
+static int handle_op(struct test_thread_data *td, int lockwakeup)
+{
+ int i, id, ret = -EINVAL;
+
+ switch(td->opcode) {
+
+ case RTTEST_NOP:
+ return 0;
+
+ case RTTEST_LOCKCONT:
+ td->mutexes[td->opdata] = 1;
+ td->event = atomic_add_return(1, &rttest_event);
+ return 0;
+
+ case RTTEST_RESET:
+ for (i = 0; i < MAX_RT_TEST_MUTEXES; i++) {
+ if (td->mutexes[i] == 4) {
+ rt_mutex_unlock(&mutexes[i]);
+ td->mutexes[i] = 0;
+ }
+ }
+ return 0;
+
+ case RTTEST_RESETEVENT:
+ atomic_set(&rttest_event, 0);
+ return 0;
+
+ default:
+ if (lockwakeup)
+ return ret;
+ }
+
+ switch(td->opcode) {
+
+ case RTTEST_LOCK:
+ case RTTEST_LOCKNOWAIT:
+ id = td->opdata;
+ if (id < 0 || id >= MAX_RT_TEST_MUTEXES)
+ return ret;
+
+ td->mutexes[id] = 1;
+ td->event = atomic_add_return(1, &rttest_event);
+ rt_mutex_lock(&mutexes[id]);
+ td->event = atomic_add_return(1, &rttest_event);
+ td->mutexes[id] = 4;
+ return 0;
+
+ case RTTEST_LOCKINT:
+ case RTTEST_LOCKINTNOWAIT:
+ id = td->opdata;
+ if (id < 0 || id >= MAX_RT_TEST_MUTEXES)
+ return ret;
+
+ td->mutexes[id] = 1;
+ td->event = atomic_add_return(1, &rttest_event);
+ ret = rt_mutex_lock_interruptible(&mutexes[id], 0);
+ td->event = atomic_add_return(1, &rttest_event);
+ td->mutexes[id] = ret ? 0 : 4;
+ return ret ? -EINTR : 0;
+
+ case RTTEST_UNLOCK:
+ id = td->opdata;
+ if (id < 0 || id >= MAX_RT_TEST_MUTEXES || td->mutexes[id] != 4)
+ return ret;
+
+ td->event = atomic_add_return(1, &rttest_event);
+ rt_mutex_unlock(&mutexes[id]);
+ td->event = atomic_add_return(1, &rttest_event);
+ td->mutexes[id] = 0;
+ return 0;
+
+ default:
+ break;
+ }
+ return ret;
+}
+
+/*
+ * Schedule replacement for rtsem_down(). Only called for threads with
+ * PF_MUTEX_TESTER set.
+ *
+ * This allows us to have finegrained control over the event flow.
+ *
+ */
+void schedule_rt_mutex_test(struct rt_mutex *mutex)
+{
+ int tid, op, dat;
+ struct test_thread_data *td;
+
+ /* We have to lookup the task */
+ for (tid = 0; tid < MAX_RT_TEST_THREADS; tid++) {
+ if (threads[tid] == current)
+ break;
+ }
+
+ BUG_ON(tid == MAX_RT_TEST_THREADS);
+
+ td = &thread_data[tid];
+
+ op = td->opcode;
+ dat = td->opdata;
+
+ switch (op) {
+ case RTTEST_LOCK:
+ case RTTEST_LOCKINT:
+ case RTTEST_LOCKNOWAIT:
+ case RTTEST_LOCKINTNOWAIT:
+ if (mutex != &mutexes[dat])
+ break;
+
+ if (td->mutexes[dat] != 1)
+ break;
+
+ td->mutexes[dat] = 2;
+ td->event = atomic_add_return(1, &rttest_event);
+ break;
+
+ default:
+ break;
+ }
+
+ schedule();
+
+
+ switch (op) {
+ case RTTEST_LOCK:
+ case RTTEST_LOCKINT:
+ if (mutex != &mutexes[dat])
+ return;
+
+ if (td->mutexes[dat] != 2)
+ return;
+
+ td->mutexes[dat] = 3;
+ td->event = atomic_add_return(1, &rttest_event);
+ break;
+
+ case RTTEST_LOCKNOWAIT:
+ case RTTEST_LOCKINTNOWAIT:
+ if (mutex != &mutexes[dat])
+ return;
+
+ if (td->mutexes[dat] != 2)
+ return;
+
+ td->mutexes[dat] = 1;
+ td->event = atomic_add_return(1, &rttest_event);
+ return;
+
+ default:
+ return;
+ }
+
+ td->opcode = 0;
+
+ for (;;) {
+ set_current_state(TASK_INTERRUPTIBLE);
+
+ if (td->opcode > 0) {
+ int ret;
+
+ set_current_state(TASK_RUNNING);
+ ret = handle_op(td, 1);
+ set_current_state(TASK_INTERRUPTIBLE);
+ if (td->opcode == RTTEST_LOCKCONT)
+ break;
+ td->opcode = ret;
+ }
+
+ /* Wait for the next command to be executed */
+ schedule();
+ }
+
+ /* Restore previous command and data */
+ td->opcode = op;
+ td->opdata = dat;
+}
+
+static int test_func(void *data)
+{
+ struct test_thread_data *td = data;
+ int ret;
+
+ current->flags |= PF_MUTEX_TESTER;
+ set_freezable();
+ allow_signal(SIGHUP);
+
+ for(;;) {
+
+ set_current_state(TASK_INTERRUPTIBLE);
+
+ if (td->opcode > 0) {
+ set_current_state(TASK_RUNNING);
+ ret = handle_op(td, 0);
+ set_current_state(TASK_INTERRUPTIBLE);
+ td->opcode = ret;
+ }
+
+ /* Wait for the next command to be executed */
+ schedule();
+ try_to_freeze();
+
+ if (signal_pending(current))
+ flush_signals(current);
+
+ if(kthread_should_stop())
+ break;
+ }
+ return 0;
+}
+
+/**
+ * sysfs_test_command - interface for test commands
+ * @dev: thread reference
+ * @buf: command for actual step
+ * @count: length of buffer
+ *
+ * command syntax:
+ *
+ * opcode:data
+ */
+static ssize_t sysfs_test_command(struct device *dev, struct device_attribute *attr,
+ const char *buf, size_t count)
+{
+ struct sched_param schedpar;
+ struct test_thread_data *td;
+ char cmdbuf[32];
+ int op, dat, tid, ret;
+
+ td = container_of(dev, struct test_thread_data, dev);
+ tid = td->dev.id;
+
+ /* strings from sysfs write are not 0 terminated! */
+ if (count >= sizeof(cmdbuf))
+ return -EINVAL;
+
+ /* strip of \n: */
+ if (buf[count-1] == '\n')
+ count--;
+ if (count < 1)
+ return -EINVAL;
+
+ memcpy(cmdbuf, buf, count);
+ cmdbuf[count] = 0;
+
+ if (sscanf(cmdbuf, "%d:%d", &op, &dat) != 2)
+ return -EINVAL;
+
+ switch (op) {
+ case RTTEST_SCHEDOT:
+ schedpar.sched_priority = 0;
+ ret = sched_setscheduler(threads[tid], SCHED_NORMAL, &schedpar);
+ if (ret)
+ return ret;
+ set_user_nice(current, 0);
+ break;
+
+ case RTTEST_SCHEDRT:
+ schedpar.sched_priority = dat;
+ ret = sched_setscheduler(threads[tid], SCHED_FIFO, &schedpar);
+ if (ret)
+ return ret;
+ break;
+
+ case RTTEST_SIGNAL:
+ send_sig(SIGHUP, threads[tid], 0);
+ break;
+
+ default:
+ if (td->opcode > 0)
+ return -EBUSY;
+ td->opdata = dat;
+ td->opcode = op;
+ wake_up_process(threads[tid]);
+ }
+
+ return count;
+}
+
+/**
+ * sysfs_test_status - sysfs interface for rt tester
+ * @dev: thread to query
+ * @buf: char buffer to be filled with thread status info
+ */
+static ssize_t sysfs_test_status(struct device *dev, struct device_attribute *attr,
+ char *buf)
+{
+ struct test_thread_data *td;
+ struct task_struct *tsk;
+ char *curr = buf;
+ int i;
+
+ td = container_of(dev, struct test_thread_data, dev);
+ tsk = threads[td->dev.id];
+
+ spin_lock(&rttest_lock);
+
+ curr += sprintf(curr,
+ "O: %4d, E:%8d, S: 0x%08lx, P: %4d, N: %4d, B: %p, M:",
+ td->opcode, td->event, tsk->state,
+ (MAX_RT_PRIO - 1) - tsk->prio,
+ (MAX_RT_PRIO - 1) - tsk->normal_prio,
+ tsk->pi_blocked_on);
+
+ for (i = MAX_RT_TEST_MUTEXES - 1; i >=0 ; i--)
+ curr += sprintf(curr, "%d", td->mutexes[i]);
+
+ spin_unlock(&rttest_lock);
+
+ curr += sprintf(curr, ", T: %p, R: %p\n", tsk,
+ mutexes[td->dev.id].owner);
+
+ return curr - buf;
+}
+
+static DEVICE_ATTR(status, S_IRUSR, sysfs_test_status, NULL);
+static DEVICE_ATTR(command, S_IWUSR, NULL, sysfs_test_command);
+
+static struct bus_type rttest_subsys = {
+ .name = "rttest",
+ .dev_name = "rttest",
+};
+
+static int init_test_thread(int id)
+{
+ thread_data[id].dev.bus = &rttest_subsys;
+ thread_data[id].dev.id = id;
+
+ threads[id] = kthread_run(test_func, &thread_data[id], "rt-test-%d", id);
+ if (IS_ERR(threads[id]))
+ return PTR_ERR(threads[id]);
+
+ return device_register(&thread_data[id].dev);
+}
+
+static int init_rttest(void)
+{
+ int ret, i;
+
+ spin_lock_init(&rttest_lock);
+
+ for (i = 0; i < MAX_RT_TEST_MUTEXES; i++)
+ rt_mutex_init(&mutexes[i]);
+
+ ret = subsys_system_register(&rttest_subsys, NULL);
+ if (ret)
+ return ret;
+
+ for (i = 0; i < MAX_RT_TEST_THREADS; i++) {
+ ret = init_test_thread(i);
+ if (ret)
+ break;
+ ret = device_create_file(&thread_data[i].dev, &dev_attr_status);
+ if (ret)
+ break;
+ ret = device_create_file(&thread_data[i].dev, &dev_attr_command);
+ if (ret)
+ break;
+ }
+
+ printk("Initializing RT-Tester: %s\n", ret ? "Failed" : "OK" );
+
+ return ret;
+}
+
+device_initcall(init_rttest);
--- /dev/null
+/*
+ * RT-Mutexes: simple blocking mutual exclusion locks with PI support
+ *
+ * started by Ingo Molnar and Thomas Gleixner.
+ *
+ * Copyright (C) 2004-2006 Red Hat, Inc., Ingo Molnar <mingo@redhat.com>
+ * Copyright (C) 2005-2006 Timesys Corp., Thomas Gleixner <tglx@timesys.com>
+ * Copyright (C) 2005 Kihon Technologies Inc., Steven Rostedt
+ * Copyright (C) 2006 Esben Nielsen
+ *
+ * See Documentation/rt-mutex-design.txt for details.
+ */
+#include <linux/spinlock.h>
+#include <linux/export.h>
+#include <linux/sched.h>
+#include <linux/sched/rt.h>
+#include <linux/timer.h>
+
+#include "rtmutex_common.h"
+
+/*
+ * lock->owner state tracking:
+ *
+ * lock->owner holds the task_struct pointer of the owner. Bit 0
+ * is used to keep track of the "lock has waiters" state.
+ *
+ * owner bit0
+ * NULL 0 lock is free (fast acquire possible)
+ * NULL 1 lock is free and has waiters and the top waiter
+ * is going to take the lock*
+ * taskpointer 0 lock is held (fast release possible)
+ * taskpointer 1 lock is held and has waiters**
+ *
+ * The fast atomic compare exchange based acquire and release is only
+ * possible when bit 0 of lock->owner is 0.
+ *
+ * (*) It also can be a transitional state when grabbing the lock
+ * with ->wait_lock is held. To prevent any fast path cmpxchg to the lock,
+ * we need to set the bit0 before looking at the lock, and the owner may be
+ * NULL in this small time, hence this can be a transitional state.
+ *
+ * (**) There is a small time when bit 0 is set but there are no
+ * waiters. This can happen when grabbing the lock in the slow path.
+ * To prevent a cmpxchg of the owner releasing the lock, we need to
+ * set this bit before looking at the lock.
+ */
+
+static void
+rt_mutex_set_owner(struct rt_mutex *lock, struct task_struct *owner)
+{
+ unsigned long val = (unsigned long)owner;
+
+ if (rt_mutex_has_waiters(lock))
+ val |= RT_MUTEX_HAS_WAITERS;
+
+ lock->owner = (struct task_struct *)val;
+}
+
+static inline void clear_rt_mutex_waiters(struct rt_mutex *lock)
+{
+ lock->owner = (struct task_struct *)
+ ((unsigned long)lock->owner & ~RT_MUTEX_HAS_WAITERS);
+}
+
+static void fixup_rt_mutex_waiters(struct rt_mutex *lock)
+{
+ if (!rt_mutex_has_waiters(lock))
+ clear_rt_mutex_waiters(lock);
+}
+
+/*
+ * We can speed up the acquire/release, if the architecture
+ * supports cmpxchg and if there's no debugging state to be set up
+ */
+#if defined(__HAVE_ARCH_CMPXCHG) && !defined(CONFIG_DEBUG_RT_MUTEXES)
+# define rt_mutex_cmpxchg(l,c,n) (cmpxchg(&l->owner, c, n) == c)
+static inline void mark_rt_mutex_waiters(struct rt_mutex *lock)
+{
+ unsigned long owner, *p = (unsigned long *) &lock->owner;
+
+ do {
+ owner = *p;
+ } while (cmpxchg(p, owner, owner | RT_MUTEX_HAS_WAITERS) != owner);
+}
+#else
+# define rt_mutex_cmpxchg(l,c,n) (0)
+static inline void mark_rt_mutex_waiters(struct rt_mutex *lock)
+{
+ lock->owner = (struct task_struct *)
+ ((unsigned long)lock->owner | RT_MUTEX_HAS_WAITERS);
+}
+#endif
+
+/*
+ * Calculate task priority from the waiter list priority
+ *
+ * Return task->normal_prio when the waiter list is empty or when
+ * the waiter is not allowed to do priority boosting
+ */
+int rt_mutex_getprio(struct task_struct *task)
+{
+ if (likely(!task_has_pi_waiters(task)))
+ return task->normal_prio;
+
+ return min(task_top_pi_waiter(task)->pi_list_entry.prio,
+ task->normal_prio);
+}
+
+/*
+ * Adjust the priority of a task, after its pi_waiters got modified.
+ *
+ * This can be both boosting and unboosting. task->pi_lock must be held.
+ */
+static void __rt_mutex_adjust_prio(struct task_struct *task)
+{
+ int prio = rt_mutex_getprio(task);
+
+ if (task->prio != prio)
+ rt_mutex_setprio(task, prio);
+}
+
+/*
+ * Adjust task priority (undo boosting). Called from the exit path of
+ * rt_mutex_slowunlock() and rt_mutex_slowlock().
+ *
+ * (Note: We do this outside of the protection of lock->wait_lock to
+ * allow the lock to be taken while or before we readjust the priority
+ * of task. We do not use the spin_xx_mutex() variants here as we are
+ * outside of the debug path.)
+ */
+static void rt_mutex_adjust_prio(struct task_struct *task)
+{
+ unsigned long flags;
+
+ raw_spin_lock_irqsave(&task->pi_lock, flags);
+ __rt_mutex_adjust_prio(task);
+ raw_spin_unlock_irqrestore(&task->pi_lock, flags);
+}
+
+/*
+ * Max number of times we'll walk the boosting chain:
+ */
+int max_lock_depth = 1024;
+
+/*
+ * Adjust the priority chain. Also used for deadlock detection.
+ * Decreases task's usage by one - may thus free the task.
+ *
+ * @task: the task owning the mutex (owner) for which a chain walk is probably
+ * needed
+ * @deadlock_detect: do we have to carry out deadlock detection?
+ * @orig_lock: the mutex (can be NULL if we are walking the chain to recheck
+ * things for a task that has just got its priority adjusted, and
+ * is waiting on a mutex)
+ * @orig_waiter: rt_mutex_waiter struct for the task that has just donated
+ * its priority to the mutex owner (can be NULL in the case
+ * depicted above or if the top waiter is gone away and we are
+ * actually deboosting the owner)
+ * @top_task: the current top waiter
+ *
+ * Returns 0 or -EDEADLK.
+ */
+static int rt_mutex_adjust_prio_chain(struct task_struct *task,
+ int deadlock_detect,
+ struct rt_mutex *orig_lock,
+ struct rt_mutex_waiter *orig_waiter,
+ struct task_struct *top_task)
+{
+ struct rt_mutex *lock;
+ struct rt_mutex_waiter *waiter, *top_waiter = orig_waiter;
+ int detect_deadlock, ret = 0, depth = 0;
+ unsigned long flags;
+
+ detect_deadlock = debug_rt_mutex_detect_deadlock(orig_waiter,
+ deadlock_detect);
+
+ /*
+ * The (de)boosting is a step by step approach with a lot of
+ * pitfalls. We want this to be preemptible and we want hold a
+ * maximum of two locks per step. So we have to check
+ * carefully whether things change under us.
+ */
+ again:
+ if (++depth > max_lock_depth) {
+ static int prev_max;
+
+ /*
+ * Print this only once. If the admin changes the limit,
+ * print a new message when reaching the limit again.
+ */
+ if (prev_max != max_lock_depth) {
+ prev_max = max_lock_depth;
+ printk(KERN_WARNING "Maximum lock depth %d reached "
+ "task: %s (%d)\n", max_lock_depth,
+ top_task->comm, task_pid_nr(top_task));
+ }
+ put_task_struct(task);
+
+ return deadlock_detect ? -EDEADLK : 0;
+ }
+ retry:
+ /*
+ * Task can not go away as we did a get_task() before !
+ */
+ raw_spin_lock_irqsave(&task->pi_lock, flags);
+
+ waiter = task->pi_blocked_on;
+ /*
+ * Check whether the end of the boosting chain has been
+ * reached or the state of the chain has changed while we
+ * dropped the locks.
+ */
+ if (!waiter)
+ goto out_unlock_pi;
+
+ /*
+ * Check the orig_waiter state. After we dropped the locks,
+ * the previous owner of the lock might have released the lock.
+ */
+ if (orig_waiter && !rt_mutex_owner(orig_lock))
+ goto out_unlock_pi;
+
+ /*
+ * Drop out, when the task has no waiters. Note,
+ * top_waiter can be NULL, when we are in the deboosting
+ * mode!
+ */
+ if (top_waiter && (!task_has_pi_waiters(task) ||
+ top_waiter != task_top_pi_waiter(task)))
+ goto out_unlock_pi;
+
+ /*
+ * When deadlock detection is off then we check, if further
+ * priority adjustment is necessary.
+ */
+ if (!detect_deadlock && waiter->list_entry.prio == task->prio)
+ goto out_unlock_pi;
+
+ lock = waiter->lock;
+ if (!raw_spin_trylock(&lock->wait_lock)) {
+ raw_spin_unlock_irqrestore(&task->pi_lock, flags);
+ cpu_relax();
+ goto retry;
+ }
+
+ /* Deadlock detection */
+ if (lock == orig_lock || rt_mutex_owner(lock) == top_task) {
+ debug_rt_mutex_deadlock(deadlock_detect, orig_waiter, lock);
+ raw_spin_unlock(&lock->wait_lock);
+ ret = deadlock_detect ? -EDEADLK : 0;
+ goto out_unlock_pi;
+ }
+
+ top_waiter = rt_mutex_top_waiter(lock);
+
+ /* Requeue the waiter */
+ plist_del(&waiter->list_entry, &lock->wait_list);
+ waiter->list_entry.prio = task->prio;
+ plist_add(&waiter->list_entry, &lock->wait_list);
+
+ /* Release the task */
+ raw_spin_unlock_irqrestore(&task->pi_lock, flags);
+ if (!rt_mutex_owner(lock)) {
+ /*
+ * If the requeue above changed the top waiter, then we need
+ * to wake the new top waiter up to try to get the lock.
+ */
+
+ if (top_waiter != rt_mutex_top_waiter(lock))
+ wake_up_process(rt_mutex_top_waiter(lock)->task);
+ raw_spin_unlock(&lock->wait_lock);
+ goto out_put_task;
+ }
+ put_task_struct(task);
+
+ /* Grab the next task */
+ task = rt_mutex_owner(lock);
+ get_task_struct(task);
+ raw_spin_lock_irqsave(&task->pi_lock, flags);
+
+ if (waiter == rt_mutex_top_waiter(lock)) {
+ /* Boost the owner */
+ plist_del(&top_waiter->pi_list_entry, &task->pi_waiters);
+ waiter->pi_list_entry.prio = waiter->list_entry.prio;
+ plist_add(&waiter->pi_list_entry, &task->pi_waiters);
+ __rt_mutex_adjust_prio(task);
+
+ } else if (top_waiter == waiter) {
+ /* Deboost the owner */
+ plist_del(&waiter->pi_list_entry, &task->pi_waiters);
+ waiter = rt_mutex_top_waiter(lock);
+ waiter->pi_list_entry.prio = waiter->list_entry.prio;
+ plist_add(&waiter->pi_list_entry, &task->pi_waiters);
+ __rt_mutex_adjust_prio(task);
+ }
+
+ raw_spin_unlock_irqrestore(&task->pi_lock, flags);
+
+ top_waiter = rt_mutex_top_waiter(lock);
+ raw_spin_unlock(&lock->wait_lock);
+
+ if (!detect_deadlock && waiter != top_waiter)
+ goto out_put_task;
+
+ goto again;
+
+ out_unlock_pi:
+ raw_spin_unlock_irqrestore(&task->pi_lock, flags);
+ out_put_task:
+ put_task_struct(task);
+
+ return ret;
+}
+
+/*
+ * Try to take an rt-mutex
+ *
+ * Must be called with lock->wait_lock held.
+ *
+ * @lock: the lock to be acquired.
+ * @task: the task which wants to acquire the lock
+ * @waiter: the waiter that is queued to the lock's wait list. (could be NULL)
+ */
+static int try_to_take_rt_mutex(struct rt_mutex *lock, struct task_struct *task,
+ struct rt_mutex_waiter *waiter)
+{
+ /*
+ * We have to be careful here if the atomic speedups are
+ * enabled, such that, when
+ * - no other waiter is on the lock
+ * - the lock has been released since we did the cmpxchg
+ * the lock can be released or taken while we are doing the
+ * checks and marking the lock with RT_MUTEX_HAS_WAITERS.
+ *
+ * The atomic acquire/release aware variant of
+ * mark_rt_mutex_waiters uses a cmpxchg loop. After setting
+ * the WAITERS bit, the atomic release / acquire can not
+ * happen anymore and lock->wait_lock protects us from the
+ * non-atomic case.
+ *
+ * Note, that this might set lock->owner =
+ * RT_MUTEX_HAS_WAITERS in the case the lock is not contended
+ * any more. This is fixed up when we take the ownership.
+ * This is the transitional state explained at the top of this file.
+ */
+ mark_rt_mutex_waiters(lock);
+
+ if (rt_mutex_owner(lock))
+ return 0;
+
+ /*
+ * It will get the lock because of one of these conditions:
+ * 1) there is no waiter
+ * 2) higher priority than waiters
+ * 3) it is top waiter
+ */
+ if (rt_mutex_has_waiters(lock)) {
+ if (task->prio >= rt_mutex_top_waiter(lock)->list_entry.prio) {
+ if (!waiter || waiter != rt_mutex_top_waiter(lock))
+ return 0;
+ }
+ }
+
+ if (waiter || rt_mutex_has_waiters(lock)) {
+ unsigned long flags;
+ struct rt_mutex_waiter *top;
+
+ raw_spin_lock_irqsave(&task->pi_lock, flags);
+
+ /* remove the queued waiter. */
+ if (waiter) {
+ plist_del(&waiter->list_entry, &lock->wait_list);
+ task->pi_blocked_on = NULL;
+ }
+
+ /*
+ * We have to enqueue the top waiter(if it exists) into
+ * task->pi_waiters list.
+ */
+ if (rt_mutex_has_waiters(lock)) {
+ top = rt_mutex_top_waiter(lock);
+ top->pi_list_entry.prio = top->list_entry.prio;
+ plist_add(&top->pi_list_entry, &task->pi_waiters);
+ }
+ raw_spin_unlock_irqrestore(&task->pi_lock, flags);
+ }
+
+ /* We got the lock. */
+ debug_rt_mutex_lock(lock);
+
+ rt_mutex_set_owner(lock, task);
+
+ rt_mutex_deadlock_account_lock(lock, task);
+
+ return 1;
+}
+
+/*
+ * Task blocks on lock.
+ *
+ * Prepare waiter and propagate pi chain
+ *
+ * This must be called with lock->wait_lock held.
+ */
+static int task_blocks_on_rt_mutex(struct rt_mutex *lock,
+ struct rt_mutex_waiter *waiter,
+ struct task_struct *task,
+ int detect_deadlock)
+{
+ struct task_struct *owner = rt_mutex_owner(lock);
+ struct rt_mutex_waiter *top_waiter = waiter;
+ unsigned long flags;
+ int chain_walk = 0, res;
+
+ raw_spin_lock_irqsave(&task->pi_lock, flags);
+ __rt_mutex_adjust_prio(task);
+ waiter->task = task;
+ waiter->lock = lock;
+ plist_node_init(&waiter->list_entry, task->prio);
+ plist_node_init(&waiter->pi_list_entry, task->prio);
+
+ /* Get the top priority waiter on the lock */
+ if (rt_mutex_has_waiters(lock))
+ top_waiter = rt_mutex_top_waiter(lock);
+ plist_add(&waiter->list_entry, &lock->wait_list);
+
+ task->pi_blocked_on = waiter;
+
+ raw_spin_unlock_irqrestore(&task->pi_lock, flags);
+
+ if (!owner)
+ return 0;
+
+ if (waiter == rt_mutex_top_waiter(lock)) {
+ raw_spin_lock_irqsave(&owner->pi_lock, flags);
+ plist_del(&top_waiter->pi_list_entry, &owner->pi_waiters);
+ plist_add(&waiter->pi_list_entry, &owner->pi_waiters);
+
+ __rt_mutex_adjust_prio(owner);
+ if (owner->pi_blocked_on)
+ chain_walk = 1;
+ raw_spin_unlock_irqrestore(&owner->pi_lock, flags);
+ }
+ else if (debug_rt_mutex_detect_deadlock(waiter, detect_deadlock))
+ chain_walk = 1;
+
+ if (!chain_walk)
+ return 0;
+
+ /*
+ * The owner can't disappear while holding a lock,
+ * so the owner struct is protected by wait_lock.
+ * Gets dropped in rt_mutex_adjust_prio_chain()!
+ */
+ get_task_struct(owner);
+
+ raw_spin_unlock(&lock->wait_lock);
+
+ res = rt_mutex_adjust_prio_chain(owner, detect_deadlock, lock, waiter,
+ task);
+
+ raw_spin_lock(&lock->wait_lock);
+
+ return res;
+}
+
+/*
+ * Wake up the next waiter on the lock.
+ *
+ * Remove the top waiter from the current tasks waiter list and wake it up.
+ *
+ * Called with lock->wait_lock held.
+ */
+static void wakeup_next_waiter(struct rt_mutex *lock)
+{
+ struct rt_mutex_waiter *waiter;
+ unsigned long flags;
+
+ raw_spin_lock_irqsave(¤t->pi_lock, flags);
+
+ waiter = rt_mutex_top_waiter(lock);
+
+ /*
+ * Remove it from current->pi_waiters. We do not adjust a
+ * possible priority boost right now. We execute wakeup in the
+ * boosted mode and go back to normal after releasing
+ * lock->wait_lock.
+ */
+ plist_del(&waiter->pi_list_entry, ¤t->pi_waiters);
+
+ rt_mutex_set_owner(lock, NULL);
+
+ raw_spin_unlock_irqrestore(¤t->pi_lock, flags);
+
+ wake_up_process(waiter->task);
+}
+
+/*
+ * Remove a waiter from a lock and give up
+ *
+ * Must be called with lock->wait_lock held and
+ * have just failed to try_to_take_rt_mutex().
+ */
+static void remove_waiter(struct rt_mutex *lock,
+ struct rt_mutex_waiter *waiter)
+{
+ int first = (waiter == rt_mutex_top_waiter(lock));
+ struct task_struct *owner = rt_mutex_owner(lock);
+ unsigned long flags;
+ int chain_walk = 0;
+
+ raw_spin_lock_irqsave(¤t->pi_lock, flags);
+ plist_del(&waiter->list_entry, &lock->wait_list);
+ current->pi_blocked_on = NULL;
+ raw_spin_unlock_irqrestore(¤t->pi_lock, flags);
+
+ if (!owner)
+ return;
+
+ if (first) {
+
+ raw_spin_lock_irqsave(&owner->pi_lock, flags);
+
+ plist_del(&waiter->pi_list_entry, &owner->pi_waiters);
+
+ if (rt_mutex_has_waiters(lock)) {
+ struct rt_mutex_waiter *next;
+
+ next = rt_mutex_top_waiter(lock);
+ plist_add(&next->pi_list_entry, &owner->pi_waiters);
+ }
+ __rt_mutex_adjust_prio(owner);
+
+ if (owner->pi_blocked_on)
+ chain_walk = 1;
+
+ raw_spin_unlock_irqrestore(&owner->pi_lock, flags);
+ }
+
+ WARN_ON(!plist_node_empty(&waiter->pi_list_entry));
+
+ if (!chain_walk)
+ return;
+
+ /* gets dropped in rt_mutex_adjust_prio_chain()! */
+ get_task_struct(owner);
+
+ raw_spin_unlock(&lock->wait_lock);
+
+ rt_mutex_adjust_prio_chain(owner, 0, lock, NULL, current);
+
+ raw_spin_lock(&lock->wait_lock);
+}
+
+/*
+ * Recheck the pi chain, in case we got a priority setting
+ *
+ * Called from sched_setscheduler
+ */
+void rt_mutex_adjust_pi(struct task_struct *task)
+{
+ struct rt_mutex_waiter *waiter;
+ unsigned long flags;
+
+ raw_spin_lock_irqsave(&task->pi_lock, flags);
+
+ waiter = task->pi_blocked_on;
+ if (!waiter || waiter->list_entry.prio == task->prio) {
+ raw_spin_unlock_irqrestore(&task->pi_lock, flags);
+ return;
+ }
+
+ raw_spin_unlock_irqrestore(&task->pi_lock, flags);
+
+ /* gets dropped in rt_mutex_adjust_prio_chain()! */
+ get_task_struct(task);
+ rt_mutex_adjust_prio_chain(task, 0, NULL, NULL, task);
+}
+
+/**
+ * __rt_mutex_slowlock() - Perform the wait-wake-try-to-take loop
+ * @lock: the rt_mutex to take
+ * @state: the state the task should block in (TASK_INTERRUPTIBLE
+ * or TASK_UNINTERRUPTIBLE)
+ * @timeout: the pre-initialized and started timer, or NULL for none
+ * @waiter: the pre-initialized rt_mutex_waiter
+ *
+ * lock->wait_lock must be held by the caller.
+ */
+static int __sched
+__rt_mutex_slowlock(struct rt_mutex *lock, int state,
+ struct hrtimer_sleeper *timeout,
+ struct rt_mutex_waiter *waiter)
+{
+ int ret = 0;
+
+ for (;;) {
+ /* Try to acquire the lock: */
+ if (try_to_take_rt_mutex(lock, current, waiter))
+ break;
+
+ /*
+ * TASK_INTERRUPTIBLE checks for signals and
+ * timeout. Ignored otherwise.
+ */
+ if (unlikely(state == TASK_INTERRUPTIBLE)) {
+ /* Signal pending? */
+ if (signal_pending(current))
+ ret = -EINTR;
+ if (timeout && !timeout->task)
+ ret = -ETIMEDOUT;
+ if (ret)
+ break;
+ }
+
+ raw_spin_unlock(&lock->wait_lock);
+
+ debug_rt_mutex_print_deadlock(waiter);
+
+ schedule_rt_mutex(lock);
+
+ raw_spin_lock(&lock->wait_lock);
+ set_current_state(state);
+ }
+
+ return ret;
+}
+
+/*
+ * Slow path lock function:
+ */
+static int __sched
+rt_mutex_slowlock(struct rt_mutex *lock, int state,
+ struct hrtimer_sleeper *timeout,
+ int detect_deadlock)
+{
+ struct rt_mutex_waiter waiter;
+ int ret = 0;
+
+ debug_rt_mutex_init_waiter(&waiter);
+
+ raw_spin_lock(&lock->wait_lock);
+
+ /* Try to acquire the lock again: */
+ if (try_to_take_rt_mutex(lock, current, NULL)) {
+ raw_spin_unlock(&lock->wait_lock);
+ return 0;
+ }
+
+ set_current_state(state);
+
+ /* Setup the timer, when timeout != NULL */
+ if (unlikely(timeout)) {
+ hrtimer_start_expires(&timeout->timer, HRTIMER_MODE_ABS);
+ if (!hrtimer_active(&timeout->timer))
+ timeout->task = NULL;
+ }
+
+ ret = task_blocks_on_rt_mutex(lock, &waiter, current, detect_deadlock);
+
+ if (likely(!ret))
+ ret = __rt_mutex_slowlock(lock, state, timeout, &waiter);
+
+ set_current_state(TASK_RUNNING);
+
+ if (unlikely(ret))
+ remove_waiter(lock, &waiter);
+
+ /*
+ * try_to_take_rt_mutex() sets the waiter bit
+ * unconditionally. We might have to fix that up.
+ */
+ fixup_rt_mutex_waiters(lock);
+
+ raw_spin_unlock(&lock->wait_lock);
+
+ /* Remove pending timer: */
+ if (unlikely(timeout))
+ hrtimer_cancel(&timeout->timer);
+
+ debug_rt_mutex_free_waiter(&waiter);
+
+ return ret;
+}
+
+/*
+ * Slow path try-lock function:
+ */
+static inline int
+rt_mutex_slowtrylock(struct rt_mutex *lock)
+{
+ int ret = 0;
+
+ raw_spin_lock(&lock->wait_lock);
+
+ if (likely(rt_mutex_owner(lock) != current)) {
+
+ ret = try_to_take_rt_mutex(lock, current, NULL);
+ /*
+ * try_to_take_rt_mutex() sets the lock waiters
+ * bit unconditionally. Clean this up.
+ */
+ fixup_rt_mutex_waiters(lock);
+ }
+
+ raw_spin_unlock(&lock->wait_lock);
+
+ return ret;
+}
+
+/*
+ * Slow path to release a rt-mutex:
+ */
+static void __sched
+rt_mutex_slowunlock(struct rt_mutex *lock)
+{
+ raw_spin_lock(&lock->wait_lock);
+
+ debug_rt_mutex_unlock(lock);
+
+ rt_mutex_deadlock_account_unlock(current);
+
+ if (!rt_mutex_has_waiters(lock)) {
+ lock->owner = NULL;
+ raw_spin_unlock(&lock->wait_lock);
+ return;
+ }
+
+ wakeup_next_waiter(lock);
+
+ raw_spin_unlock(&lock->wait_lock);
+
+ /* Undo pi boosting if necessary: */
+ rt_mutex_adjust_prio(current);
+}
+
+/*
+ * debug aware fast / slowpath lock,trylock,unlock
+ *
+ * The atomic acquire/release ops are compiled away, when either the
+ * architecture does not support cmpxchg or when debugging is enabled.
+ */
+static inline int
+rt_mutex_fastlock(struct rt_mutex *lock, int state,
+ int detect_deadlock,
+ int (*slowfn)(struct rt_mutex *lock, int state,
+ struct hrtimer_sleeper *timeout,
+ int detect_deadlock))
+{
+ if (!detect_deadlock && likely(rt_mutex_cmpxchg(lock, NULL, current))) {
+ rt_mutex_deadlock_account_lock(lock, current);
+ return 0;
+ } else
+ return slowfn(lock, state, NULL, detect_deadlock);
+}
+
+static inline int
+rt_mutex_timed_fastlock(struct rt_mutex *lock, int state,
+ struct hrtimer_sleeper *timeout, int detect_deadlock,
+ int (*slowfn)(struct rt_mutex *lock, int state,
+ struct hrtimer_sleeper *timeout,
+ int detect_deadlock))
+{
+ if (!detect_deadlock && likely(rt_mutex_cmpxchg(lock, NULL, current))) {
+ rt_mutex_deadlock_account_lock(lock, current);
+ return 0;
+ } else
+ return slowfn(lock, state, timeout, detect_deadlock);
+}
+
+static inline int
+rt_mutex_fasttrylock(struct rt_mutex *lock,
+ int (*slowfn)(struct rt_mutex *lock))
+{
+ if (likely(rt_mutex_cmpxchg(lock, NULL, current))) {
+ rt_mutex_deadlock_account_lock(lock, current);
+ return 1;
+ }
+ return slowfn(lock);
+}
+
+static inline void
+rt_mutex_fastunlock(struct rt_mutex *lock,
+ void (*slowfn)(struct rt_mutex *lock))
+{
+ if (likely(rt_mutex_cmpxchg(lock, current, NULL)))
+ rt_mutex_deadlock_account_unlock(current);
+ else
+ slowfn(lock);
+}
+
+/**
+ * rt_mutex_lock - lock a rt_mutex
+ *
+ * @lock: the rt_mutex to be locked
+ */
+void __sched rt_mutex_lock(struct rt_mutex *lock)
+{
+ might_sleep();
+
+ rt_mutex_fastlock(lock, TASK_UNINTERRUPTIBLE, 0, rt_mutex_slowlock);
+}
+EXPORT_SYMBOL_GPL(rt_mutex_lock);
+
+/**
+ * rt_mutex_lock_interruptible - lock a rt_mutex interruptible
+ *
+ * @lock: the rt_mutex to be locked
+ * @detect_deadlock: deadlock detection on/off
+ *
+ * Returns:
+ * 0 on success
+ * -EINTR when interrupted by a signal
+ * -EDEADLK when the lock would deadlock (when deadlock detection is on)
+ */
+int __sched rt_mutex_lock_interruptible(struct rt_mutex *lock,
+ int detect_deadlock)
+{
+ might_sleep();
+
+ return rt_mutex_fastlock(lock, TASK_INTERRUPTIBLE,
+ detect_deadlock, rt_mutex_slowlock);
+}
+EXPORT_SYMBOL_GPL(rt_mutex_lock_interruptible);
+
+/**
+ * rt_mutex_timed_lock - lock a rt_mutex interruptible
+ * the timeout structure is provided
+ * by the caller
+ *
+ * @lock: the rt_mutex to be locked
+ * @timeout: timeout structure or NULL (no timeout)
+ * @detect_deadlock: deadlock detection on/off
+ *
+ * Returns:
+ * 0 on success
+ * -EINTR when interrupted by a signal
+ * -ETIMEDOUT when the timeout expired
+ * -EDEADLK when the lock would deadlock (when deadlock detection is on)
+ */
+int
+rt_mutex_timed_lock(struct rt_mutex *lock, struct hrtimer_sleeper *timeout,
+ int detect_deadlock)
+{
+ might_sleep();
+
+ return rt_mutex_timed_fastlock(lock, TASK_INTERRUPTIBLE, timeout,
+ detect_deadlock, rt_mutex_slowlock);
+}
+EXPORT_SYMBOL_GPL(rt_mutex_timed_lock);
+
+/**
+ * rt_mutex_trylock - try to lock a rt_mutex
+ *
+ * @lock: the rt_mutex to be locked
+ *
+ * Returns 1 on success and 0 on contention
+ */
+int __sched rt_mutex_trylock(struct rt_mutex *lock)
+{
+ return rt_mutex_fasttrylock(lock, rt_mutex_slowtrylock);
+}
+EXPORT_SYMBOL_GPL(rt_mutex_trylock);
+
+/**
+ * rt_mutex_unlock - unlock a rt_mutex
+ *
+ * @lock: the rt_mutex to be unlocked
+ */
+void __sched rt_mutex_unlock(struct rt_mutex *lock)
+{
+ rt_mutex_fastunlock(lock, rt_mutex_slowunlock);
+}
+EXPORT_SYMBOL_GPL(rt_mutex_unlock);
+
+/**
+ * rt_mutex_destroy - mark a mutex unusable
+ * @lock: the mutex to be destroyed
+ *
+ * This function marks the mutex uninitialized, and any subsequent
+ * use of the mutex is forbidden. The mutex must not be locked when
+ * this function is called.
+ */
+void rt_mutex_destroy(struct rt_mutex *lock)
+{
+ WARN_ON(rt_mutex_is_locked(lock));
+#ifdef CONFIG_DEBUG_RT_MUTEXES
+ lock->magic = NULL;
+#endif
+}
+
+EXPORT_SYMBOL_GPL(rt_mutex_destroy);
+
+/**
+ * __rt_mutex_init - initialize the rt lock
+ *
+ * @lock: the rt lock to be initialized
+ *
+ * Initialize the rt lock to unlocked state.
+ *
+ * Initializing of a locked rt lock is not allowed
+ */
+void __rt_mutex_init(struct rt_mutex *lock, const char *name)
+{
+ lock->owner = NULL;
+ raw_spin_lock_init(&lock->wait_lock);
+ plist_head_init(&lock->wait_list);
+
+ debug_rt_mutex_init(lock, name);
+}
+EXPORT_SYMBOL_GPL(__rt_mutex_init);
+
+/**
+ * rt_mutex_init_proxy_locked - initialize and lock a rt_mutex on behalf of a
+ * proxy owner
+ *
+ * @lock: the rt_mutex to be locked
+ * @proxy_owner:the task to set as owner
+ *
+ * No locking. Caller has to do serializing itself
+ * Special API call for PI-futex support
+ */
+void rt_mutex_init_proxy_locked(struct rt_mutex *lock,
+ struct task_struct *proxy_owner)
+{
+ __rt_mutex_init(lock, NULL);
+ debug_rt_mutex_proxy_lock(lock, proxy_owner);
+ rt_mutex_set_owner(lock, proxy_owner);
+ rt_mutex_deadlock_account_lock(lock, proxy_owner);
+}
+
+/**
+ * rt_mutex_proxy_unlock - release a lock on behalf of owner
+ *
+ * @lock: the rt_mutex to be locked
+ *
+ * No locking. Caller has to do serializing itself
+ * Special API call for PI-futex support
+ */
+void rt_mutex_proxy_unlock(struct rt_mutex *lock,
+ struct task_struct *proxy_owner)
+{
+ debug_rt_mutex_proxy_unlock(lock);
+ rt_mutex_set_owner(lock, NULL);
+ rt_mutex_deadlock_account_unlock(proxy_owner);
+}
+
+/**
+ * rt_mutex_start_proxy_lock() - Start lock acquisition for another task
+ * @lock: the rt_mutex to take
+ * @waiter: the pre-initialized rt_mutex_waiter
+ * @task: the task to prepare
+ * @detect_deadlock: perform deadlock detection (1) or not (0)
+ *
+ * Returns:
+ * 0 - task blocked on lock
+ * 1 - acquired the lock for task, caller should wake it up
+ * <0 - error
+ *
+ * Special API call for FUTEX_REQUEUE_PI support.
+ */
+int rt_mutex_start_proxy_lock(struct rt_mutex *lock,
+ struct rt_mutex_waiter *waiter,
+ struct task_struct *task, int detect_deadlock)
+{
+ int ret;
+
+ raw_spin_lock(&lock->wait_lock);
+
+ if (try_to_take_rt_mutex(lock, task, NULL)) {
+ raw_spin_unlock(&lock->wait_lock);
+ return 1;
+ }
+
+ ret = task_blocks_on_rt_mutex(lock, waiter, task, detect_deadlock);
+
+ if (ret && !rt_mutex_owner(lock)) {
+ /*
+ * Reset the return value. We might have
+ * returned with -EDEADLK and the owner
+ * released the lock while we were walking the
+ * pi chain. Let the waiter sort it out.
+ */
+ ret = 0;
+ }
+
+ if (unlikely(ret))
+ remove_waiter(lock, waiter);
+
+ raw_spin_unlock(&lock->wait_lock);
+
+ debug_rt_mutex_print_deadlock(waiter);
+
+ return ret;
+}
+
+/**
+ * rt_mutex_next_owner - return the next owner of the lock
+ *
+ * @lock: the rt lock query
+ *
+ * Returns the next owner of the lock or NULL
+ *
+ * Caller has to serialize against other accessors to the lock
+ * itself.
+ *
+ * Special API call for PI-futex support
+ */
+struct task_struct *rt_mutex_next_owner(struct rt_mutex *lock)
+{
+ if (!rt_mutex_has_waiters(lock))
+ return NULL;
+
+ return rt_mutex_top_waiter(lock)->task;
+}
+
+/**
+ * rt_mutex_finish_proxy_lock() - Complete lock acquisition
+ * @lock: the rt_mutex we were woken on
+ * @to: the timeout, null if none. hrtimer should already have
+ * been started.
+ * @waiter: the pre-initialized rt_mutex_waiter
+ * @detect_deadlock: perform deadlock detection (1) or not (0)
+ *
+ * Complete the lock acquisition started our behalf by another thread.
+ *
+ * Returns:
+ * 0 - success
+ * <0 - error, one of -EINTR, -ETIMEDOUT, or -EDEADLK
+ *
+ * Special API call for PI-futex requeue support
+ */
+int rt_mutex_finish_proxy_lock(struct rt_mutex *lock,
+ struct hrtimer_sleeper *to,
+ struct rt_mutex_waiter *waiter,
+ int detect_deadlock)
+{
+ int ret;
+
+ raw_spin_lock(&lock->wait_lock);
+
+ set_current_state(TASK_INTERRUPTIBLE);
+
+ ret = __rt_mutex_slowlock(lock, TASK_INTERRUPTIBLE, to, waiter);
+
+ set_current_state(TASK_RUNNING);
+
+ if (unlikely(ret))
+ remove_waiter(lock, waiter);
+
+ /*
+ * try_to_take_rt_mutex() sets the waiter bit unconditionally. We might
+ * have to fix that up.
+ */
+ fixup_rt_mutex_waiters(lock);
+
+ raw_spin_unlock(&lock->wait_lock);
+
+ return ret;
+}
--- /dev/null
+/*
+ * RT-Mutexes: blocking mutual exclusion locks with PI support
+ *
+ * started by Ingo Molnar and Thomas Gleixner:
+ *
+ * Copyright (C) 2004-2006 Red Hat, Inc., Ingo Molnar <mingo@redhat.com>
+ * Copyright (C) 2006, Timesys Corp., Thomas Gleixner <tglx@timesys.com>
+ *
+ * This file contains macros used solely by rtmutex.c.
+ * Non-debug version.
+ */
+
+#define rt_mutex_deadlock_check(l) (0)
+#define rt_mutex_deadlock_account_lock(m, t) do { } while (0)
+#define rt_mutex_deadlock_account_unlock(l) do { } while (0)
+#define debug_rt_mutex_init_waiter(w) do { } while (0)
+#define debug_rt_mutex_free_waiter(w) do { } while (0)
+#define debug_rt_mutex_lock(l) do { } while (0)
+#define debug_rt_mutex_proxy_lock(l,p) do { } while (0)
+#define debug_rt_mutex_proxy_unlock(l) do { } while (0)
+#define debug_rt_mutex_unlock(l) do { } while (0)
+#define debug_rt_mutex_init(m, n) do { } while (0)
+#define debug_rt_mutex_deadlock(d, a ,l) do { } while (0)
+#define debug_rt_mutex_print_deadlock(w) do { } while (0)
+#define debug_rt_mutex_detect_deadlock(w,d) (d)
+#define debug_rt_mutex_reset_waiter(w) do { } while (0)
--- /dev/null
+/*
+ * RT Mutexes: blocking mutual exclusion locks with PI support
+ *
+ * started by Ingo Molnar and Thomas Gleixner:
+ *
+ * Copyright (C) 2004-2006 Red Hat, Inc., Ingo Molnar <mingo@redhat.com>
+ * Copyright (C) 2006, Timesys Corp., Thomas Gleixner <tglx@timesys.com>
+ *
+ * This file contains the private data structure and API definitions.
+ */
+
+#ifndef __KERNEL_RTMUTEX_COMMON_H
+#define __KERNEL_RTMUTEX_COMMON_H
+
+#include <linux/rtmutex.h>
+
+/*
+ * The rtmutex in kernel tester is independent of rtmutex debugging. We
+ * call schedule_rt_mutex_test() instead of schedule() for the tasks which
+ * belong to the tester. That way we can delay the wakeup path of those
+ * threads to provoke lock stealing and testing of complex boosting scenarios.
+ */
+#ifdef CONFIG_RT_MUTEX_TESTER
+
+extern void schedule_rt_mutex_test(struct rt_mutex *lock);
+
+#define schedule_rt_mutex(_lock) \
+ do { \
+ if (!(current->flags & PF_MUTEX_TESTER)) \
+ schedule(); \
+ else \
+ schedule_rt_mutex_test(_lock); \
+ } while (0)
+
+#else
+# define schedule_rt_mutex(_lock) schedule()
+#endif
+
+/*
+ * This is the control structure for tasks blocked on a rt_mutex,
+ * which is allocated on the kernel stack on of the blocked task.
+ *
+ * @list_entry: pi node to enqueue into the mutex waiters list
+ * @pi_list_entry: pi node to enqueue into the mutex owner waiters list
+ * @task: task reference to the blocked task
+ */
+struct rt_mutex_waiter {
+ struct plist_node list_entry;
+ struct plist_node pi_list_entry;
+ struct task_struct *task;
+ struct rt_mutex *lock;
+#ifdef CONFIG_DEBUG_RT_MUTEXES
+ unsigned long ip;
+ struct pid *deadlock_task_pid;
+ struct rt_mutex *deadlock_lock;
+#endif
+};
+
+/*
+ * Various helpers to access the waiters-plist:
+ */
+static inline int rt_mutex_has_waiters(struct rt_mutex *lock)
+{
+ return !plist_head_empty(&lock->wait_list);
+}
+
+static inline struct rt_mutex_waiter *
+rt_mutex_top_waiter(struct rt_mutex *lock)
+{
+ struct rt_mutex_waiter *w;
+
+ w = plist_first_entry(&lock->wait_list, struct rt_mutex_waiter,
+ list_entry);
+ BUG_ON(w->lock != lock);
+
+ return w;
+}
+
+static inline int task_has_pi_waiters(struct task_struct *p)
+{
+ return !plist_head_empty(&p->pi_waiters);
+}
+
+static inline struct rt_mutex_waiter *
+task_top_pi_waiter(struct task_struct *p)
+{
+ return plist_first_entry(&p->pi_waiters, struct rt_mutex_waiter,
+ pi_list_entry);
+}
+
+/*
+ * lock->owner state tracking:
+ */
+#define RT_MUTEX_HAS_WAITERS 1UL
+#define RT_MUTEX_OWNER_MASKALL 1UL
+
+static inline struct task_struct *rt_mutex_owner(struct rt_mutex *lock)
+{
+ return (struct task_struct *)
+ ((unsigned long)lock->owner & ~RT_MUTEX_OWNER_MASKALL);
+}
+
+/*
+ * PI-futex support (proxy locking functions, etc.):
+ */
+extern struct task_struct *rt_mutex_next_owner(struct rt_mutex *lock);
+extern void rt_mutex_init_proxy_locked(struct rt_mutex *lock,
+ struct task_struct *proxy_owner);
+extern void rt_mutex_proxy_unlock(struct rt_mutex *lock,
+ struct task_struct *proxy_owner);
+extern int rt_mutex_start_proxy_lock(struct rt_mutex *lock,
+ struct rt_mutex_waiter *waiter,
+ struct task_struct *task,
+ int detect_deadlock);
+extern int rt_mutex_finish_proxy_lock(struct rt_mutex *lock,
+ struct hrtimer_sleeper *to,
+ struct rt_mutex_waiter *waiter,
+ int detect_deadlock);
+
+#ifdef CONFIG_DEBUG_RT_MUTEXES
+# include "rtmutex-debug.h"
+#else
+# include "rtmutex.h"
+#endif
+
+#endif
#ifdef CONFIG_RCU_BOOST
-#include "../rtmutex_common.h"
+#include "../locking/rtmutex_common.h"
#ifdef CONFIG_RCU_TRACE
+++ /dev/null
-/*
- * RT-Mutexes: blocking mutual exclusion locks with PI support
- *
- * started by Ingo Molnar and Thomas Gleixner:
- *
- * Copyright (C) 2004-2006 Red Hat, Inc., Ingo Molnar <mingo@redhat.com>
- * Copyright (C) 2006 Timesys Corp., Thomas Gleixner <tglx@timesys.com>
- *
- * This code is based on the rt.c implementation in the preempt-rt tree.
- * Portions of said code are
- *
- * Copyright (C) 2004 LynuxWorks, Inc., Igor Manyilov, Bill Huey
- * Copyright (C) 2006 Esben Nielsen
- * Copyright (C) 2006 Kihon Technologies Inc.,
- * Steven Rostedt <rostedt@goodmis.org>
- *
- * See rt.c in preempt-rt for proper credits and further information
- */
-#include <linux/sched.h>
-#include <linux/sched/rt.h>
-#include <linux/delay.h>
-#include <linux/export.h>
-#include <linux/spinlock.h>
-#include <linux/kallsyms.h>
-#include <linux/syscalls.h>
-#include <linux/interrupt.h>
-#include <linux/plist.h>
-#include <linux/fs.h>
-#include <linux/debug_locks.h>
-
-#include "rtmutex_common.h"
-
-static void printk_task(struct task_struct *p)
-{
- if (p)
- printk("%16s:%5d [%p, %3d]", p->comm, task_pid_nr(p), p, p->prio);
- else
- printk("<none>");
-}
-
-static void printk_lock(struct rt_mutex *lock, int print_owner)
-{
- if (lock->name)
- printk(" [%p] {%s}\n",
- lock, lock->name);
- else
- printk(" [%p] {%s:%d}\n",
- lock, lock->file, lock->line);
-
- if (print_owner && rt_mutex_owner(lock)) {
- printk(".. ->owner: %p\n", lock->owner);
- printk(".. held by: ");
- printk_task(rt_mutex_owner(lock));
- printk("\n");
- }
-}
-
-void rt_mutex_debug_task_free(struct task_struct *task)
-{
- DEBUG_LOCKS_WARN_ON(!plist_head_empty(&task->pi_waiters));
- DEBUG_LOCKS_WARN_ON(task->pi_blocked_on);
-}
-
-/*
- * We fill out the fields in the waiter to store the information about
- * the deadlock. We print when we return. act_waiter can be NULL in
- * case of a remove waiter operation.
- */
-void debug_rt_mutex_deadlock(int detect, struct rt_mutex_waiter *act_waiter,
- struct rt_mutex *lock)
-{
- struct task_struct *task;
-
- if (!debug_locks || detect || !act_waiter)
- return;
-
- task = rt_mutex_owner(act_waiter->lock);
- if (task && task != current) {
- act_waiter->deadlock_task_pid = get_pid(task_pid(task));
- act_waiter->deadlock_lock = lock;
- }
-}
-
-void debug_rt_mutex_print_deadlock(struct rt_mutex_waiter *waiter)
-{
- struct task_struct *task;
-
- if (!waiter->deadlock_lock || !debug_locks)
- return;
-
- rcu_read_lock();
- task = pid_task(waiter->deadlock_task_pid, PIDTYPE_PID);
- if (!task) {
- rcu_read_unlock();
- return;
- }
-
- if (!debug_locks_off()) {
- rcu_read_unlock();
- return;
- }
-
- printk("\n============================================\n");
- printk( "[ BUG: circular locking deadlock detected! ]\n");
- printk("%s\n", print_tainted());
- printk( "--------------------------------------------\n");
- printk("%s/%d is deadlocking current task %s/%d\n\n",
- task->comm, task_pid_nr(task),
- current->comm, task_pid_nr(current));
-
- printk("\n1) %s/%d is trying to acquire this lock:\n",
- current->comm, task_pid_nr(current));
- printk_lock(waiter->lock, 1);
-
- printk("\n2) %s/%d is blocked on this lock:\n",
- task->comm, task_pid_nr(task));
- printk_lock(waiter->deadlock_lock, 1);
-
- debug_show_held_locks(current);
- debug_show_held_locks(task);
-
- printk("\n%s/%d's [blocked] stackdump:\n\n",
- task->comm, task_pid_nr(task));
- show_stack(task, NULL);
- printk("\n%s/%d's [current] stackdump:\n\n",
- current->comm, task_pid_nr(current));
- dump_stack();
- debug_show_all_locks();
- rcu_read_unlock();
-
- printk("[ turning off deadlock detection."
- "Please report this trace. ]\n\n");
-}
-
-void debug_rt_mutex_lock(struct rt_mutex *lock)
-{
-}
-
-void debug_rt_mutex_unlock(struct rt_mutex *lock)
-{
- DEBUG_LOCKS_WARN_ON(rt_mutex_owner(lock) != current);
-}
-
-void
-debug_rt_mutex_proxy_lock(struct rt_mutex *lock, struct task_struct *powner)
-{
-}
-
-void debug_rt_mutex_proxy_unlock(struct rt_mutex *lock)
-{
- DEBUG_LOCKS_WARN_ON(!rt_mutex_owner(lock));
-}
-
-void debug_rt_mutex_init_waiter(struct rt_mutex_waiter *waiter)
-{
- memset(waiter, 0x11, sizeof(*waiter));
- plist_node_init(&waiter->list_entry, MAX_PRIO);
- plist_node_init(&waiter->pi_list_entry, MAX_PRIO);
- waiter->deadlock_task_pid = NULL;
-}
-
-void debug_rt_mutex_free_waiter(struct rt_mutex_waiter *waiter)
-{
- put_pid(waiter->deadlock_task_pid);
- DEBUG_LOCKS_WARN_ON(!plist_node_empty(&waiter->list_entry));
- DEBUG_LOCKS_WARN_ON(!plist_node_empty(&waiter->pi_list_entry));
- memset(waiter, 0x22, sizeof(*waiter));
-}
-
-void debug_rt_mutex_init(struct rt_mutex *lock, const char *name)
-{
- /*
- * Make sure we are not reinitializing a held lock:
- */
- debug_check_no_locks_freed((void *)lock, sizeof(*lock));
- lock->name = name;
-}
-
-void
-rt_mutex_deadlock_account_lock(struct rt_mutex *lock, struct task_struct *task)
-{
-}
-
-void rt_mutex_deadlock_account_unlock(struct task_struct *task)
-{
-}
-
+++ /dev/null
-/*
- * RT-Mutexes: blocking mutual exclusion locks with PI support
- *
- * started by Ingo Molnar and Thomas Gleixner:
- *
- * Copyright (C) 2004-2006 Red Hat, Inc., Ingo Molnar <mingo@redhat.com>
- * Copyright (C) 2006, Timesys Corp., Thomas Gleixner <tglx@timesys.com>
- *
- * This file contains macros used solely by rtmutex.c. Debug version.
- */
-
-extern void
-rt_mutex_deadlock_account_lock(struct rt_mutex *lock, struct task_struct *task);
-extern void rt_mutex_deadlock_account_unlock(struct task_struct *task);
-extern void debug_rt_mutex_init_waiter(struct rt_mutex_waiter *waiter);
-extern void debug_rt_mutex_free_waiter(struct rt_mutex_waiter *waiter);
-extern void debug_rt_mutex_init(struct rt_mutex *lock, const char *name);
-extern void debug_rt_mutex_lock(struct rt_mutex *lock);
-extern void debug_rt_mutex_unlock(struct rt_mutex *lock);
-extern void debug_rt_mutex_proxy_lock(struct rt_mutex *lock,
- struct task_struct *powner);
-extern void debug_rt_mutex_proxy_unlock(struct rt_mutex *lock);
-extern void debug_rt_mutex_deadlock(int detect, struct rt_mutex_waiter *waiter,
- struct rt_mutex *lock);
-extern void debug_rt_mutex_print_deadlock(struct rt_mutex_waiter *waiter);
-# define debug_rt_mutex_reset_waiter(w) \
- do { (w)->deadlock_lock = NULL; } while (0)
-
-static inline int debug_rt_mutex_detect_deadlock(struct rt_mutex_waiter *waiter,
- int detect)
-{
- return (waiter != NULL);
-}
+++ /dev/null
-/*
- * RT-Mutex-tester: scriptable tester for rt mutexes
- *
- * started by Thomas Gleixner:
- *
- * Copyright (C) 2006, Timesys Corp., Thomas Gleixner <tglx@timesys.com>
- *
- */
-#include <linux/device.h>
-#include <linux/kthread.h>
-#include <linux/export.h>
-#include <linux/sched.h>
-#include <linux/sched/rt.h>
-#include <linux/spinlock.h>
-#include <linux/timer.h>
-#include <linux/freezer.h>
-#include <linux/stat.h>
-
-#include "rtmutex.h"
-
-#define MAX_RT_TEST_THREADS 8
-#define MAX_RT_TEST_MUTEXES 8
-
-static spinlock_t rttest_lock;
-static atomic_t rttest_event;
-
-struct test_thread_data {
- int opcode;
- int opdata;
- int mutexes[MAX_RT_TEST_MUTEXES];
- int event;
- struct device dev;
-};
-
-static struct test_thread_data thread_data[MAX_RT_TEST_THREADS];
-static struct task_struct *threads[MAX_RT_TEST_THREADS];
-static struct rt_mutex mutexes[MAX_RT_TEST_MUTEXES];
-
-enum test_opcodes {
- RTTEST_NOP = 0,
- RTTEST_SCHEDOT, /* 1 Sched other, data = nice */
- RTTEST_SCHEDRT, /* 2 Sched fifo, data = prio */
- RTTEST_LOCK, /* 3 Lock uninterruptible, data = lockindex */
- RTTEST_LOCKNOWAIT, /* 4 Lock uninterruptible no wait in wakeup, data = lockindex */
- RTTEST_LOCKINT, /* 5 Lock interruptible, data = lockindex */
- RTTEST_LOCKINTNOWAIT, /* 6 Lock interruptible no wait in wakeup, data = lockindex */
- RTTEST_LOCKCONT, /* 7 Continue locking after the wakeup delay */
- RTTEST_UNLOCK, /* 8 Unlock, data = lockindex */
- /* 9, 10 - reserved for BKL commemoration */
- RTTEST_SIGNAL = 11, /* 11 Signal other test thread, data = thread id */
- RTTEST_RESETEVENT = 98, /* 98 Reset event counter */
- RTTEST_RESET = 99, /* 99 Reset all pending operations */
-};
-
-static int handle_op(struct test_thread_data *td, int lockwakeup)
-{
- int i, id, ret = -EINVAL;
-
- switch(td->opcode) {
-
- case RTTEST_NOP:
- return 0;
-
- case RTTEST_LOCKCONT:
- td->mutexes[td->opdata] = 1;
- td->event = atomic_add_return(1, &rttest_event);
- return 0;
-
- case RTTEST_RESET:
- for (i = 0; i < MAX_RT_TEST_MUTEXES; i++) {
- if (td->mutexes[i] == 4) {
- rt_mutex_unlock(&mutexes[i]);
- td->mutexes[i] = 0;
- }
- }
- return 0;
-
- case RTTEST_RESETEVENT:
- atomic_set(&rttest_event, 0);
- return 0;
-
- default:
- if (lockwakeup)
- return ret;
- }
-
- switch(td->opcode) {
-
- case RTTEST_LOCK:
- case RTTEST_LOCKNOWAIT:
- id = td->opdata;
- if (id < 0 || id >= MAX_RT_TEST_MUTEXES)
- return ret;
-
- td->mutexes[id] = 1;
- td->event = atomic_add_return(1, &rttest_event);
- rt_mutex_lock(&mutexes[id]);
- td->event = atomic_add_return(1, &rttest_event);
- td->mutexes[id] = 4;
- return 0;
-
- case RTTEST_LOCKINT:
- case RTTEST_LOCKINTNOWAIT:
- id = td->opdata;
- if (id < 0 || id >= MAX_RT_TEST_MUTEXES)
- return ret;
-
- td->mutexes[id] = 1;
- td->event = atomic_add_return(1, &rttest_event);
- ret = rt_mutex_lock_interruptible(&mutexes[id], 0);
- td->event = atomic_add_return(1, &rttest_event);
- td->mutexes[id] = ret ? 0 : 4;
- return ret ? -EINTR : 0;
-
- case RTTEST_UNLOCK:
- id = td->opdata;
- if (id < 0 || id >= MAX_RT_TEST_MUTEXES || td->mutexes[id] != 4)
- return ret;
-
- td->event = atomic_add_return(1, &rttest_event);
- rt_mutex_unlock(&mutexes[id]);
- td->event = atomic_add_return(1, &rttest_event);
- td->mutexes[id] = 0;
- return 0;
-
- default:
- break;
- }
- return ret;
-}
-
-/*
- * Schedule replacement for rtsem_down(). Only called for threads with
- * PF_MUTEX_TESTER set.
- *
- * This allows us to have finegrained control over the event flow.
- *
- */
-void schedule_rt_mutex_test(struct rt_mutex *mutex)
-{
- int tid, op, dat;
- struct test_thread_data *td;
-
- /* We have to lookup the task */
- for (tid = 0; tid < MAX_RT_TEST_THREADS; tid++) {
- if (threads[tid] == current)
- break;
- }
-
- BUG_ON(tid == MAX_RT_TEST_THREADS);
-
- td = &thread_data[tid];
-
- op = td->opcode;
- dat = td->opdata;
-
- switch (op) {
- case RTTEST_LOCK:
- case RTTEST_LOCKINT:
- case RTTEST_LOCKNOWAIT:
- case RTTEST_LOCKINTNOWAIT:
- if (mutex != &mutexes[dat])
- break;
-
- if (td->mutexes[dat] != 1)
- break;
-
- td->mutexes[dat] = 2;
- td->event = atomic_add_return(1, &rttest_event);
- break;
-
- default:
- break;
- }
-
- schedule();
-
-
- switch (op) {
- case RTTEST_LOCK:
- case RTTEST_LOCKINT:
- if (mutex != &mutexes[dat])
- return;
-
- if (td->mutexes[dat] != 2)
- return;
-
- td->mutexes[dat] = 3;
- td->event = atomic_add_return(1, &rttest_event);
- break;
-
- case RTTEST_LOCKNOWAIT:
- case RTTEST_LOCKINTNOWAIT:
- if (mutex != &mutexes[dat])
- return;
-
- if (td->mutexes[dat] != 2)
- return;
-
- td->mutexes[dat] = 1;
- td->event = atomic_add_return(1, &rttest_event);
- return;
-
- default:
- return;
- }
-
- td->opcode = 0;
-
- for (;;) {
- set_current_state(TASK_INTERRUPTIBLE);
-
- if (td->opcode > 0) {
- int ret;
-
- set_current_state(TASK_RUNNING);
- ret = handle_op(td, 1);
- set_current_state(TASK_INTERRUPTIBLE);
- if (td->opcode == RTTEST_LOCKCONT)
- break;
- td->opcode = ret;
- }
-
- /* Wait for the next command to be executed */
- schedule();
- }
-
- /* Restore previous command and data */
- td->opcode = op;
- td->opdata = dat;
-}
-
-static int test_func(void *data)
-{
- struct test_thread_data *td = data;
- int ret;
-
- current->flags |= PF_MUTEX_TESTER;
- set_freezable();
- allow_signal(SIGHUP);
-
- for(;;) {
-
- set_current_state(TASK_INTERRUPTIBLE);
-
- if (td->opcode > 0) {
- set_current_state(TASK_RUNNING);
- ret = handle_op(td, 0);
- set_current_state(TASK_INTERRUPTIBLE);
- td->opcode = ret;
- }
-
- /* Wait for the next command to be executed */
- schedule();
- try_to_freeze();
-
- if (signal_pending(current))
- flush_signals(current);
-
- if(kthread_should_stop())
- break;
- }
- return 0;
-}
-
-/**
- * sysfs_test_command - interface for test commands
- * @dev: thread reference
- * @buf: command for actual step
- * @count: length of buffer
- *
- * command syntax:
- *
- * opcode:data
- */
-static ssize_t sysfs_test_command(struct device *dev, struct device_attribute *attr,
- const char *buf, size_t count)
-{
- struct sched_param schedpar;
- struct test_thread_data *td;
- char cmdbuf[32];
- int op, dat, tid, ret;
-
- td = container_of(dev, struct test_thread_data, dev);
- tid = td->dev.id;
-
- /* strings from sysfs write are not 0 terminated! */
- if (count >= sizeof(cmdbuf))
- return -EINVAL;
-
- /* strip of \n: */
- if (buf[count-1] == '\n')
- count--;
- if (count < 1)
- return -EINVAL;
-
- memcpy(cmdbuf, buf, count);
- cmdbuf[count] = 0;
-
- if (sscanf(cmdbuf, "%d:%d", &op, &dat) != 2)
- return -EINVAL;
-
- switch (op) {
- case RTTEST_SCHEDOT:
- schedpar.sched_priority = 0;
- ret = sched_setscheduler(threads[tid], SCHED_NORMAL, &schedpar);
- if (ret)
- return ret;
- set_user_nice(current, 0);
- break;
-
- case RTTEST_SCHEDRT:
- schedpar.sched_priority = dat;
- ret = sched_setscheduler(threads[tid], SCHED_FIFO, &schedpar);
- if (ret)
- return ret;
- break;
-
- case RTTEST_SIGNAL:
- send_sig(SIGHUP, threads[tid], 0);
- break;
-
- default:
- if (td->opcode > 0)
- return -EBUSY;
- td->opdata = dat;
- td->opcode = op;
- wake_up_process(threads[tid]);
- }
-
- return count;
-}
-
-/**
- * sysfs_test_status - sysfs interface for rt tester
- * @dev: thread to query
- * @buf: char buffer to be filled with thread status info
- */
-static ssize_t sysfs_test_status(struct device *dev, struct device_attribute *attr,
- char *buf)
-{
- struct test_thread_data *td;
- struct task_struct *tsk;
- char *curr = buf;
- int i;
-
- td = container_of(dev, struct test_thread_data, dev);
- tsk = threads[td->dev.id];
-
- spin_lock(&rttest_lock);
-
- curr += sprintf(curr,
- "O: %4d, E:%8d, S: 0x%08lx, P: %4d, N: %4d, B: %p, M:",
- td->opcode, td->event, tsk->state,
- (MAX_RT_PRIO - 1) - tsk->prio,
- (MAX_RT_PRIO - 1) - tsk->normal_prio,
- tsk->pi_blocked_on);
-
- for (i = MAX_RT_TEST_MUTEXES - 1; i >=0 ; i--)
- curr += sprintf(curr, "%d", td->mutexes[i]);
-
- spin_unlock(&rttest_lock);
-
- curr += sprintf(curr, ", T: %p, R: %p\n", tsk,
- mutexes[td->dev.id].owner);
-
- return curr - buf;
-}
-
-static DEVICE_ATTR(status, S_IRUSR, sysfs_test_status, NULL);
-static DEVICE_ATTR(command, S_IWUSR, NULL, sysfs_test_command);
-
-static struct bus_type rttest_subsys = {
- .name = "rttest",
- .dev_name = "rttest",
-};
-
-static int init_test_thread(int id)
-{
- thread_data[id].dev.bus = &rttest_subsys;
- thread_data[id].dev.id = id;
-
- threads[id] = kthread_run(test_func, &thread_data[id], "rt-test-%d", id);
- if (IS_ERR(threads[id]))
- return PTR_ERR(threads[id]);
-
- return device_register(&thread_data[id].dev);
-}
-
-static int init_rttest(void)
-{
- int ret, i;
-
- spin_lock_init(&rttest_lock);
-
- for (i = 0; i < MAX_RT_TEST_MUTEXES; i++)
- rt_mutex_init(&mutexes[i]);
-
- ret = subsys_system_register(&rttest_subsys, NULL);
- if (ret)
- return ret;
-
- for (i = 0; i < MAX_RT_TEST_THREADS; i++) {
- ret = init_test_thread(i);
- if (ret)
- break;
- ret = device_create_file(&thread_data[i].dev, &dev_attr_status);
- if (ret)
- break;
- ret = device_create_file(&thread_data[i].dev, &dev_attr_command);
- if (ret)
- break;
- }
-
- printk("Initializing RT-Tester: %s\n", ret ? "Failed" : "OK" );
-
- return ret;
-}
-
-device_initcall(init_rttest);
+++ /dev/null
-/*
- * RT-Mutexes: simple blocking mutual exclusion locks with PI support
- *
- * started by Ingo Molnar and Thomas Gleixner.
- *
- * Copyright (C) 2004-2006 Red Hat, Inc., Ingo Molnar <mingo@redhat.com>
- * Copyright (C) 2005-2006 Timesys Corp., Thomas Gleixner <tglx@timesys.com>
- * Copyright (C) 2005 Kihon Technologies Inc., Steven Rostedt
- * Copyright (C) 2006 Esben Nielsen
- *
- * See Documentation/rt-mutex-design.txt for details.
- */
-#include <linux/spinlock.h>
-#include <linux/export.h>
-#include <linux/sched.h>
-#include <linux/sched/rt.h>
-#include <linux/timer.h>
-
-#include "rtmutex_common.h"
-
-/*
- * lock->owner state tracking:
- *
- * lock->owner holds the task_struct pointer of the owner. Bit 0
- * is used to keep track of the "lock has waiters" state.
- *
- * owner bit0
- * NULL 0 lock is free (fast acquire possible)
- * NULL 1 lock is free and has waiters and the top waiter
- * is going to take the lock*
- * taskpointer 0 lock is held (fast release possible)
- * taskpointer 1 lock is held and has waiters**
- *
- * The fast atomic compare exchange based acquire and release is only
- * possible when bit 0 of lock->owner is 0.
- *
- * (*) It also can be a transitional state when grabbing the lock
- * with ->wait_lock is held. To prevent any fast path cmpxchg to the lock,
- * we need to set the bit0 before looking at the lock, and the owner may be
- * NULL in this small time, hence this can be a transitional state.
- *
- * (**) There is a small time when bit 0 is set but there are no
- * waiters. This can happen when grabbing the lock in the slow path.
- * To prevent a cmpxchg of the owner releasing the lock, we need to
- * set this bit before looking at the lock.
- */
-
-static void
-rt_mutex_set_owner(struct rt_mutex *lock, struct task_struct *owner)
-{
- unsigned long val = (unsigned long)owner;
-
- if (rt_mutex_has_waiters(lock))
- val |= RT_MUTEX_HAS_WAITERS;
-
- lock->owner = (struct task_struct *)val;
-}
-
-static inline void clear_rt_mutex_waiters(struct rt_mutex *lock)
-{
- lock->owner = (struct task_struct *)
- ((unsigned long)lock->owner & ~RT_MUTEX_HAS_WAITERS);
-}
-
-static void fixup_rt_mutex_waiters(struct rt_mutex *lock)
-{
- if (!rt_mutex_has_waiters(lock))
- clear_rt_mutex_waiters(lock);
-}
-
-/*
- * We can speed up the acquire/release, if the architecture
- * supports cmpxchg and if there's no debugging state to be set up
- */
-#if defined(__HAVE_ARCH_CMPXCHG) && !defined(CONFIG_DEBUG_RT_MUTEXES)
-# define rt_mutex_cmpxchg(l,c,n) (cmpxchg(&l->owner, c, n) == c)
-static inline void mark_rt_mutex_waiters(struct rt_mutex *lock)
-{
- unsigned long owner, *p = (unsigned long *) &lock->owner;
-
- do {
- owner = *p;
- } while (cmpxchg(p, owner, owner | RT_MUTEX_HAS_WAITERS) != owner);
-}
-#else
-# define rt_mutex_cmpxchg(l,c,n) (0)
-static inline void mark_rt_mutex_waiters(struct rt_mutex *lock)
-{
- lock->owner = (struct task_struct *)
- ((unsigned long)lock->owner | RT_MUTEX_HAS_WAITERS);
-}
-#endif
-
-/*
- * Calculate task priority from the waiter list priority
- *
- * Return task->normal_prio when the waiter list is empty or when
- * the waiter is not allowed to do priority boosting
- */
-int rt_mutex_getprio(struct task_struct *task)
-{
- if (likely(!task_has_pi_waiters(task)))
- return task->normal_prio;
-
- return min(task_top_pi_waiter(task)->pi_list_entry.prio,
- task->normal_prio);
-}
-
-/*
- * Adjust the priority of a task, after its pi_waiters got modified.
- *
- * This can be both boosting and unboosting. task->pi_lock must be held.
- */
-static void __rt_mutex_adjust_prio(struct task_struct *task)
-{
- int prio = rt_mutex_getprio(task);
-
- if (task->prio != prio)
- rt_mutex_setprio(task, prio);
-}
-
-/*
- * Adjust task priority (undo boosting). Called from the exit path of
- * rt_mutex_slowunlock() and rt_mutex_slowlock().
- *
- * (Note: We do this outside of the protection of lock->wait_lock to
- * allow the lock to be taken while or before we readjust the priority
- * of task. We do not use the spin_xx_mutex() variants here as we are
- * outside of the debug path.)
- */
-static void rt_mutex_adjust_prio(struct task_struct *task)
-{
- unsigned long flags;
-
- raw_spin_lock_irqsave(&task->pi_lock, flags);
- __rt_mutex_adjust_prio(task);
- raw_spin_unlock_irqrestore(&task->pi_lock, flags);
-}
-
-/*
- * Max number of times we'll walk the boosting chain:
- */
-int max_lock_depth = 1024;
-
-/*
- * Adjust the priority chain. Also used for deadlock detection.
- * Decreases task's usage by one - may thus free the task.
- *
- * @task: the task owning the mutex (owner) for which a chain walk is probably
- * needed
- * @deadlock_detect: do we have to carry out deadlock detection?
- * @orig_lock: the mutex (can be NULL if we are walking the chain to recheck
- * things for a task that has just got its priority adjusted, and
- * is waiting on a mutex)
- * @orig_waiter: rt_mutex_waiter struct for the task that has just donated
- * its priority to the mutex owner (can be NULL in the case
- * depicted above or if the top waiter is gone away and we are
- * actually deboosting the owner)
- * @top_task: the current top waiter
- *
- * Returns 0 or -EDEADLK.
- */
-static int rt_mutex_adjust_prio_chain(struct task_struct *task,
- int deadlock_detect,
- struct rt_mutex *orig_lock,
- struct rt_mutex_waiter *orig_waiter,
- struct task_struct *top_task)
-{
- struct rt_mutex *lock;
- struct rt_mutex_waiter *waiter, *top_waiter = orig_waiter;
- int detect_deadlock, ret = 0, depth = 0;
- unsigned long flags;
-
- detect_deadlock = debug_rt_mutex_detect_deadlock(orig_waiter,
- deadlock_detect);
-
- /*
- * The (de)boosting is a step by step approach with a lot of
- * pitfalls. We want this to be preemptible and we want hold a
- * maximum of two locks per step. So we have to check
- * carefully whether things change under us.
- */
- again:
- if (++depth > max_lock_depth) {
- static int prev_max;
-
- /*
- * Print this only once. If the admin changes the limit,
- * print a new message when reaching the limit again.
- */
- if (prev_max != max_lock_depth) {
- prev_max = max_lock_depth;
- printk(KERN_WARNING "Maximum lock depth %d reached "
- "task: %s (%d)\n", max_lock_depth,
- top_task->comm, task_pid_nr(top_task));
- }
- put_task_struct(task);
-
- return deadlock_detect ? -EDEADLK : 0;
- }
- retry:
- /*
- * Task can not go away as we did a get_task() before !
- */
- raw_spin_lock_irqsave(&task->pi_lock, flags);
-
- waiter = task->pi_blocked_on;
- /*
- * Check whether the end of the boosting chain has been
- * reached or the state of the chain has changed while we
- * dropped the locks.
- */
- if (!waiter)
- goto out_unlock_pi;
-
- /*
- * Check the orig_waiter state. After we dropped the locks,
- * the previous owner of the lock might have released the lock.
- */
- if (orig_waiter && !rt_mutex_owner(orig_lock))
- goto out_unlock_pi;
-
- /*
- * Drop out, when the task has no waiters. Note,
- * top_waiter can be NULL, when we are in the deboosting
- * mode!
- */
- if (top_waiter && (!task_has_pi_waiters(task) ||
- top_waiter != task_top_pi_waiter(task)))
- goto out_unlock_pi;
-
- /*
- * When deadlock detection is off then we check, if further
- * priority adjustment is necessary.
- */
- if (!detect_deadlock && waiter->list_entry.prio == task->prio)
- goto out_unlock_pi;
-
- lock = waiter->lock;
- if (!raw_spin_trylock(&lock->wait_lock)) {
- raw_spin_unlock_irqrestore(&task->pi_lock, flags);
- cpu_relax();
- goto retry;
- }
-
- /* Deadlock detection */
- if (lock == orig_lock || rt_mutex_owner(lock) == top_task) {
- debug_rt_mutex_deadlock(deadlock_detect, orig_waiter, lock);
- raw_spin_unlock(&lock->wait_lock);
- ret = deadlock_detect ? -EDEADLK : 0;
- goto out_unlock_pi;
- }
-
- top_waiter = rt_mutex_top_waiter(lock);
-
- /* Requeue the waiter */
- plist_del(&waiter->list_entry, &lock->wait_list);
- waiter->list_entry.prio = task->prio;
- plist_add(&waiter->list_entry, &lock->wait_list);
-
- /* Release the task */
- raw_spin_unlock_irqrestore(&task->pi_lock, flags);
- if (!rt_mutex_owner(lock)) {
- /*
- * If the requeue above changed the top waiter, then we need
- * to wake the new top waiter up to try to get the lock.
- */
-
- if (top_waiter != rt_mutex_top_waiter(lock))
- wake_up_process(rt_mutex_top_waiter(lock)->task);
- raw_spin_unlock(&lock->wait_lock);
- goto out_put_task;
- }
- put_task_struct(task);
-
- /* Grab the next task */
- task = rt_mutex_owner(lock);
- get_task_struct(task);
- raw_spin_lock_irqsave(&task->pi_lock, flags);
-
- if (waiter == rt_mutex_top_waiter(lock)) {
- /* Boost the owner */
- plist_del(&top_waiter->pi_list_entry, &task->pi_waiters);
- waiter->pi_list_entry.prio = waiter->list_entry.prio;
- plist_add(&waiter->pi_list_entry, &task->pi_waiters);
- __rt_mutex_adjust_prio(task);
-
- } else if (top_waiter == waiter) {
- /* Deboost the owner */
- plist_del(&waiter->pi_list_entry, &task->pi_waiters);
- waiter = rt_mutex_top_waiter(lock);
- waiter->pi_list_entry.prio = waiter->list_entry.prio;
- plist_add(&waiter->pi_list_entry, &task->pi_waiters);
- __rt_mutex_adjust_prio(task);
- }
-
- raw_spin_unlock_irqrestore(&task->pi_lock, flags);
-
- top_waiter = rt_mutex_top_waiter(lock);
- raw_spin_unlock(&lock->wait_lock);
-
- if (!detect_deadlock && waiter != top_waiter)
- goto out_put_task;
-
- goto again;
-
- out_unlock_pi:
- raw_spin_unlock_irqrestore(&task->pi_lock, flags);
- out_put_task:
- put_task_struct(task);
-
- return ret;
-}
-
-/*
- * Try to take an rt-mutex
- *
- * Must be called with lock->wait_lock held.
- *
- * @lock: the lock to be acquired.
- * @task: the task which wants to acquire the lock
- * @waiter: the waiter that is queued to the lock's wait list. (could be NULL)
- */
-static int try_to_take_rt_mutex(struct rt_mutex *lock, struct task_struct *task,
- struct rt_mutex_waiter *waiter)
-{
- /*
- * We have to be careful here if the atomic speedups are
- * enabled, such that, when
- * - no other waiter is on the lock
- * - the lock has been released since we did the cmpxchg
- * the lock can be released or taken while we are doing the
- * checks and marking the lock with RT_MUTEX_HAS_WAITERS.
- *
- * The atomic acquire/release aware variant of
- * mark_rt_mutex_waiters uses a cmpxchg loop. After setting
- * the WAITERS bit, the atomic release / acquire can not
- * happen anymore and lock->wait_lock protects us from the
- * non-atomic case.
- *
- * Note, that this might set lock->owner =
- * RT_MUTEX_HAS_WAITERS in the case the lock is not contended
- * any more. This is fixed up when we take the ownership.
- * This is the transitional state explained at the top of this file.
- */
- mark_rt_mutex_waiters(lock);
-
- if (rt_mutex_owner(lock))
- return 0;
-
- /*
- * It will get the lock because of one of these conditions:
- * 1) there is no waiter
- * 2) higher priority than waiters
- * 3) it is top waiter
- */
- if (rt_mutex_has_waiters(lock)) {
- if (task->prio >= rt_mutex_top_waiter(lock)->list_entry.prio) {
- if (!waiter || waiter != rt_mutex_top_waiter(lock))
- return 0;
- }
- }
-
- if (waiter || rt_mutex_has_waiters(lock)) {
- unsigned long flags;
- struct rt_mutex_waiter *top;
-
- raw_spin_lock_irqsave(&task->pi_lock, flags);
-
- /* remove the queued waiter. */
- if (waiter) {
- plist_del(&waiter->list_entry, &lock->wait_list);
- task->pi_blocked_on = NULL;
- }
-
- /*
- * We have to enqueue the top waiter(if it exists) into
- * task->pi_waiters list.
- */
- if (rt_mutex_has_waiters(lock)) {
- top = rt_mutex_top_waiter(lock);
- top->pi_list_entry.prio = top->list_entry.prio;
- plist_add(&top->pi_list_entry, &task->pi_waiters);
- }
- raw_spin_unlock_irqrestore(&task->pi_lock, flags);
- }
-
- /* We got the lock. */
- debug_rt_mutex_lock(lock);
-
- rt_mutex_set_owner(lock, task);
-
- rt_mutex_deadlock_account_lock(lock, task);
-
- return 1;
-}
-
-/*
- * Task blocks on lock.
- *
- * Prepare waiter and propagate pi chain
- *
- * This must be called with lock->wait_lock held.
- */
-static int task_blocks_on_rt_mutex(struct rt_mutex *lock,
- struct rt_mutex_waiter *waiter,
- struct task_struct *task,
- int detect_deadlock)
-{
- struct task_struct *owner = rt_mutex_owner(lock);
- struct rt_mutex_waiter *top_waiter = waiter;
- unsigned long flags;
- int chain_walk = 0, res;
-
- raw_spin_lock_irqsave(&task->pi_lock, flags);
- __rt_mutex_adjust_prio(task);
- waiter->task = task;
- waiter->lock = lock;
- plist_node_init(&waiter->list_entry, task->prio);
- plist_node_init(&waiter->pi_list_entry, task->prio);
-
- /* Get the top priority waiter on the lock */
- if (rt_mutex_has_waiters(lock))
- top_waiter = rt_mutex_top_waiter(lock);
- plist_add(&waiter->list_entry, &lock->wait_list);
-
- task->pi_blocked_on = waiter;
-
- raw_spin_unlock_irqrestore(&task->pi_lock, flags);
-
- if (!owner)
- return 0;
-
- if (waiter == rt_mutex_top_waiter(lock)) {
- raw_spin_lock_irqsave(&owner->pi_lock, flags);
- plist_del(&top_waiter->pi_list_entry, &owner->pi_waiters);
- plist_add(&waiter->pi_list_entry, &owner->pi_waiters);
-
- __rt_mutex_adjust_prio(owner);
- if (owner->pi_blocked_on)
- chain_walk = 1;
- raw_spin_unlock_irqrestore(&owner->pi_lock, flags);
- }
- else if (debug_rt_mutex_detect_deadlock(waiter, detect_deadlock))
- chain_walk = 1;
-
- if (!chain_walk)
- return 0;
-
- /*
- * The owner can't disappear while holding a lock,
- * so the owner struct is protected by wait_lock.
- * Gets dropped in rt_mutex_adjust_prio_chain()!
- */
- get_task_struct(owner);
-
- raw_spin_unlock(&lock->wait_lock);
-
- res = rt_mutex_adjust_prio_chain(owner, detect_deadlock, lock, waiter,
- task);
-
- raw_spin_lock(&lock->wait_lock);
-
- return res;
-}
-
-/*
- * Wake up the next waiter on the lock.
- *
- * Remove the top waiter from the current tasks waiter list and wake it up.
- *
- * Called with lock->wait_lock held.
- */
-static void wakeup_next_waiter(struct rt_mutex *lock)
-{
- struct rt_mutex_waiter *waiter;
- unsigned long flags;
-
- raw_spin_lock_irqsave(¤t->pi_lock, flags);
-
- waiter = rt_mutex_top_waiter(lock);
-
- /*
- * Remove it from current->pi_waiters. We do not adjust a
- * possible priority boost right now. We execute wakeup in the
- * boosted mode and go back to normal after releasing
- * lock->wait_lock.
- */
- plist_del(&waiter->pi_list_entry, ¤t->pi_waiters);
-
- rt_mutex_set_owner(lock, NULL);
-
- raw_spin_unlock_irqrestore(¤t->pi_lock, flags);
-
- wake_up_process(waiter->task);
-}
-
-/*
- * Remove a waiter from a lock and give up
- *
- * Must be called with lock->wait_lock held and
- * have just failed to try_to_take_rt_mutex().
- */
-static void remove_waiter(struct rt_mutex *lock,
- struct rt_mutex_waiter *waiter)
-{
- int first = (waiter == rt_mutex_top_waiter(lock));
- struct task_struct *owner = rt_mutex_owner(lock);
- unsigned long flags;
- int chain_walk = 0;
-
- raw_spin_lock_irqsave(¤t->pi_lock, flags);
- plist_del(&waiter->list_entry, &lock->wait_list);
- current->pi_blocked_on = NULL;
- raw_spin_unlock_irqrestore(¤t->pi_lock, flags);
-
- if (!owner)
- return;
-
- if (first) {
-
- raw_spin_lock_irqsave(&owner->pi_lock, flags);
-
- plist_del(&waiter->pi_list_entry, &owner->pi_waiters);
-
- if (rt_mutex_has_waiters(lock)) {
- struct rt_mutex_waiter *next;
-
- next = rt_mutex_top_waiter(lock);
- plist_add(&next->pi_list_entry, &owner->pi_waiters);
- }
- __rt_mutex_adjust_prio(owner);
-
- if (owner->pi_blocked_on)
- chain_walk = 1;
-
- raw_spin_unlock_irqrestore(&owner->pi_lock, flags);
- }
-
- WARN_ON(!plist_node_empty(&waiter->pi_list_entry));
-
- if (!chain_walk)
- return;
-
- /* gets dropped in rt_mutex_adjust_prio_chain()! */
- get_task_struct(owner);
-
- raw_spin_unlock(&lock->wait_lock);
-
- rt_mutex_adjust_prio_chain(owner, 0, lock, NULL, current);
-
- raw_spin_lock(&lock->wait_lock);
-}
-
-/*
- * Recheck the pi chain, in case we got a priority setting
- *
- * Called from sched_setscheduler
- */
-void rt_mutex_adjust_pi(struct task_struct *task)
-{
- struct rt_mutex_waiter *waiter;
- unsigned long flags;
-
- raw_spin_lock_irqsave(&task->pi_lock, flags);
-
- waiter = task->pi_blocked_on;
- if (!waiter || waiter->list_entry.prio == task->prio) {
- raw_spin_unlock_irqrestore(&task->pi_lock, flags);
- return;
- }
-
- raw_spin_unlock_irqrestore(&task->pi_lock, flags);
-
- /* gets dropped in rt_mutex_adjust_prio_chain()! */
- get_task_struct(task);
- rt_mutex_adjust_prio_chain(task, 0, NULL, NULL, task);
-}
-
-/**
- * __rt_mutex_slowlock() - Perform the wait-wake-try-to-take loop
- * @lock: the rt_mutex to take
- * @state: the state the task should block in (TASK_INTERRUPTIBLE
- * or TASK_UNINTERRUPTIBLE)
- * @timeout: the pre-initialized and started timer, or NULL for none
- * @waiter: the pre-initialized rt_mutex_waiter
- *
- * lock->wait_lock must be held by the caller.
- */
-static int __sched
-__rt_mutex_slowlock(struct rt_mutex *lock, int state,
- struct hrtimer_sleeper *timeout,
- struct rt_mutex_waiter *waiter)
-{
- int ret = 0;
-
- for (;;) {
- /* Try to acquire the lock: */
- if (try_to_take_rt_mutex(lock, current, waiter))
- break;
-
- /*
- * TASK_INTERRUPTIBLE checks for signals and
- * timeout. Ignored otherwise.
- */
- if (unlikely(state == TASK_INTERRUPTIBLE)) {
- /* Signal pending? */
- if (signal_pending(current))
- ret = -EINTR;
- if (timeout && !timeout->task)
- ret = -ETIMEDOUT;
- if (ret)
- break;
- }
-
- raw_spin_unlock(&lock->wait_lock);
-
- debug_rt_mutex_print_deadlock(waiter);
-
- schedule_rt_mutex(lock);
-
- raw_spin_lock(&lock->wait_lock);
- set_current_state(state);
- }
-
- return ret;
-}
-
-/*
- * Slow path lock function:
- */
-static int __sched
-rt_mutex_slowlock(struct rt_mutex *lock, int state,
- struct hrtimer_sleeper *timeout,
- int detect_deadlock)
-{
- struct rt_mutex_waiter waiter;
- int ret = 0;
-
- debug_rt_mutex_init_waiter(&waiter);
-
- raw_spin_lock(&lock->wait_lock);
-
- /* Try to acquire the lock again: */
- if (try_to_take_rt_mutex(lock, current, NULL)) {
- raw_spin_unlock(&lock->wait_lock);
- return 0;
- }
-
- set_current_state(state);
-
- /* Setup the timer, when timeout != NULL */
- if (unlikely(timeout)) {
- hrtimer_start_expires(&timeout->timer, HRTIMER_MODE_ABS);
- if (!hrtimer_active(&timeout->timer))
- timeout->task = NULL;
- }
-
- ret = task_blocks_on_rt_mutex(lock, &waiter, current, detect_deadlock);
-
- if (likely(!ret))
- ret = __rt_mutex_slowlock(lock, state, timeout, &waiter);
-
- set_current_state(TASK_RUNNING);
-
- if (unlikely(ret))
- remove_waiter(lock, &waiter);
-
- /*
- * try_to_take_rt_mutex() sets the waiter bit
- * unconditionally. We might have to fix that up.
- */
- fixup_rt_mutex_waiters(lock);
-
- raw_spin_unlock(&lock->wait_lock);
-
- /* Remove pending timer: */
- if (unlikely(timeout))
- hrtimer_cancel(&timeout->timer);
-
- debug_rt_mutex_free_waiter(&waiter);
-
- return ret;
-}
-
-/*
- * Slow path try-lock function:
- */
-static inline int
-rt_mutex_slowtrylock(struct rt_mutex *lock)
-{
- int ret = 0;
-
- raw_spin_lock(&lock->wait_lock);
-
- if (likely(rt_mutex_owner(lock) != current)) {
-
- ret = try_to_take_rt_mutex(lock, current, NULL);
- /*
- * try_to_take_rt_mutex() sets the lock waiters
- * bit unconditionally. Clean this up.
- */
- fixup_rt_mutex_waiters(lock);
- }
-
- raw_spin_unlock(&lock->wait_lock);
-
- return ret;
-}
-
-/*
- * Slow path to release a rt-mutex:
- */
-static void __sched
-rt_mutex_slowunlock(struct rt_mutex *lock)
-{
- raw_spin_lock(&lock->wait_lock);
-
- debug_rt_mutex_unlock(lock);
-
- rt_mutex_deadlock_account_unlock(current);
-
- if (!rt_mutex_has_waiters(lock)) {
- lock->owner = NULL;
- raw_spin_unlock(&lock->wait_lock);
- return;
- }
-
- wakeup_next_waiter(lock);
-
- raw_spin_unlock(&lock->wait_lock);
-
- /* Undo pi boosting if necessary: */
- rt_mutex_adjust_prio(current);
-}
-
-/*
- * debug aware fast / slowpath lock,trylock,unlock
- *
- * The atomic acquire/release ops are compiled away, when either the
- * architecture does not support cmpxchg or when debugging is enabled.
- */
-static inline int
-rt_mutex_fastlock(struct rt_mutex *lock, int state,
- int detect_deadlock,
- int (*slowfn)(struct rt_mutex *lock, int state,
- struct hrtimer_sleeper *timeout,
- int detect_deadlock))
-{
- if (!detect_deadlock && likely(rt_mutex_cmpxchg(lock, NULL, current))) {
- rt_mutex_deadlock_account_lock(lock, current);
- return 0;
- } else
- return slowfn(lock, state, NULL, detect_deadlock);
-}
-
-static inline int
-rt_mutex_timed_fastlock(struct rt_mutex *lock, int state,
- struct hrtimer_sleeper *timeout, int detect_deadlock,
- int (*slowfn)(struct rt_mutex *lock, int state,
- struct hrtimer_sleeper *timeout,
- int detect_deadlock))
-{
- if (!detect_deadlock && likely(rt_mutex_cmpxchg(lock, NULL, current))) {
- rt_mutex_deadlock_account_lock(lock, current);
- return 0;
- } else
- return slowfn(lock, state, timeout, detect_deadlock);
-}
-
-static inline int
-rt_mutex_fasttrylock(struct rt_mutex *lock,
- int (*slowfn)(struct rt_mutex *lock))
-{
- if (likely(rt_mutex_cmpxchg(lock, NULL, current))) {
- rt_mutex_deadlock_account_lock(lock, current);
- return 1;
- }
- return slowfn(lock);
-}
-
-static inline void
-rt_mutex_fastunlock(struct rt_mutex *lock,
- void (*slowfn)(struct rt_mutex *lock))
-{
- if (likely(rt_mutex_cmpxchg(lock, current, NULL)))
- rt_mutex_deadlock_account_unlock(current);
- else
- slowfn(lock);
-}
-
-/**
- * rt_mutex_lock - lock a rt_mutex
- *
- * @lock: the rt_mutex to be locked
- */
-void __sched rt_mutex_lock(struct rt_mutex *lock)
-{
- might_sleep();
-
- rt_mutex_fastlock(lock, TASK_UNINTERRUPTIBLE, 0, rt_mutex_slowlock);
-}
-EXPORT_SYMBOL_GPL(rt_mutex_lock);
-
-/**
- * rt_mutex_lock_interruptible - lock a rt_mutex interruptible
- *
- * @lock: the rt_mutex to be locked
- * @detect_deadlock: deadlock detection on/off
- *
- * Returns:
- * 0 on success
- * -EINTR when interrupted by a signal
- * -EDEADLK when the lock would deadlock (when deadlock detection is on)
- */
-int __sched rt_mutex_lock_interruptible(struct rt_mutex *lock,
- int detect_deadlock)
-{
- might_sleep();
-
- return rt_mutex_fastlock(lock, TASK_INTERRUPTIBLE,
- detect_deadlock, rt_mutex_slowlock);
-}
-EXPORT_SYMBOL_GPL(rt_mutex_lock_interruptible);
-
-/**
- * rt_mutex_timed_lock - lock a rt_mutex interruptible
- * the timeout structure is provided
- * by the caller
- *
- * @lock: the rt_mutex to be locked
- * @timeout: timeout structure or NULL (no timeout)
- * @detect_deadlock: deadlock detection on/off
- *
- * Returns:
- * 0 on success
- * -EINTR when interrupted by a signal
- * -ETIMEDOUT when the timeout expired
- * -EDEADLK when the lock would deadlock (when deadlock detection is on)
- */
-int
-rt_mutex_timed_lock(struct rt_mutex *lock, struct hrtimer_sleeper *timeout,
- int detect_deadlock)
-{
- might_sleep();
-
- return rt_mutex_timed_fastlock(lock, TASK_INTERRUPTIBLE, timeout,
- detect_deadlock, rt_mutex_slowlock);
-}
-EXPORT_SYMBOL_GPL(rt_mutex_timed_lock);
-
-/**
- * rt_mutex_trylock - try to lock a rt_mutex
- *
- * @lock: the rt_mutex to be locked
- *
- * Returns 1 on success and 0 on contention
- */
-int __sched rt_mutex_trylock(struct rt_mutex *lock)
-{
- return rt_mutex_fasttrylock(lock, rt_mutex_slowtrylock);
-}
-EXPORT_SYMBOL_GPL(rt_mutex_trylock);
-
-/**
- * rt_mutex_unlock - unlock a rt_mutex
- *
- * @lock: the rt_mutex to be unlocked
- */
-void __sched rt_mutex_unlock(struct rt_mutex *lock)
-{
- rt_mutex_fastunlock(lock, rt_mutex_slowunlock);
-}
-EXPORT_SYMBOL_GPL(rt_mutex_unlock);
-
-/**
- * rt_mutex_destroy - mark a mutex unusable
- * @lock: the mutex to be destroyed
- *
- * This function marks the mutex uninitialized, and any subsequent
- * use of the mutex is forbidden. The mutex must not be locked when
- * this function is called.
- */
-void rt_mutex_destroy(struct rt_mutex *lock)
-{
- WARN_ON(rt_mutex_is_locked(lock));
-#ifdef CONFIG_DEBUG_RT_MUTEXES
- lock->magic = NULL;
-#endif
-}
-
-EXPORT_SYMBOL_GPL(rt_mutex_destroy);
-
-/**
- * __rt_mutex_init - initialize the rt lock
- *
- * @lock: the rt lock to be initialized
- *
- * Initialize the rt lock to unlocked state.
- *
- * Initializing of a locked rt lock is not allowed
- */
-void __rt_mutex_init(struct rt_mutex *lock, const char *name)
-{
- lock->owner = NULL;
- raw_spin_lock_init(&lock->wait_lock);
- plist_head_init(&lock->wait_list);
-
- debug_rt_mutex_init(lock, name);
-}
-EXPORT_SYMBOL_GPL(__rt_mutex_init);
-
-/**
- * rt_mutex_init_proxy_locked - initialize and lock a rt_mutex on behalf of a
- * proxy owner
- *
- * @lock: the rt_mutex to be locked
- * @proxy_owner:the task to set as owner
- *
- * No locking. Caller has to do serializing itself
- * Special API call for PI-futex support
- */
-void rt_mutex_init_proxy_locked(struct rt_mutex *lock,
- struct task_struct *proxy_owner)
-{
- __rt_mutex_init(lock, NULL);
- debug_rt_mutex_proxy_lock(lock, proxy_owner);
- rt_mutex_set_owner(lock, proxy_owner);
- rt_mutex_deadlock_account_lock(lock, proxy_owner);
-}
-
-/**
- * rt_mutex_proxy_unlock - release a lock on behalf of owner
- *
- * @lock: the rt_mutex to be locked
- *
- * No locking. Caller has to do serializing itself
- * Special API call for PI-futex support
- */
-void rt_mutex_proxy_unlock(struct rt_mutex *lock,
- struct task_struct *proxy_owner)
-{
- debug_rt_mutex_proxy_unlock(lock);
- rt_mutex_set_owner(lock, NULL);
- rt_mutex_deadlock_account_unlock(proxy_owner);
-}
-
-/**
- * rt_mutex_start_proxy_lock() - Start lock acquisition for another task
- * @lock: the rt_mutex to take
- * @waiter: the pre-initialized rt_mutex_waiter
- * @task: the task to prepare
- * @detect_deadlock: perform deadlock detection (1) or not (0)
- *
- * Returns:
- * 0 - task blocked on lock
- * 1 - acquired the lock for task, caller should wake it up
- * <0 - error
- *
- * Special API call for FUTEX_REQUEUE_PI support.
- */
-int rt_mutex_start_proxy_lock(struct rt_mutex *lock,
- struct rt_mutex_waiter *waiter,
- struct task_struct *task, int detect_deadlock)
-{
- int ret;
-
- raw_spin_lock(&lock->wait_lock);
-
- if (try_to_take_rt_mutex(lock, task, NULL)) {
- raw_spin_unlock(&lock->wait_lock);
- return 1;
- }
-
- ret = task_blocks_on_rt_mutex(lock, waiter, task, detect_deadlock);
-
- if (ret && !rt_mutex_owner(lock)) {
- /*
- * Reset the return value. We might have
- * returned with -EDEADLK and the owner
- * released the lock while we were walking the
- * pi chain. Let the waiter sort it out.
- */
- ret = 0;
- }
-
- if (unlikely(ret))
- remove_waiter(lock, waiter);
-
- raw_spin_unlock(&lock->wait_lock);
-
- debug_rt_mutex_print_deadlock(waiter);
-
- return ret;
-}
-
-/**
- * rt_mutex_next_owner - return the next owner of the lock
- *
- * @lock: the rt lock query
- *
- * Returns the next owner of the lock or NULL
- *
- * Caller has to serialize against other accessors to the lock
- * itself.
- *
- * Special API call for PI-futex support
- */
-struct task_struct *rt_mutex_next_owner(struct rt_mutex *lock)
-{
- if (!rt_mutex_has_waiters(lock))
- return NULL;
-
- return rt_mutex_top_waiter(lock)->task;
-}
-
-/**
- * rt_mutex_finish_proxy_lock() - Complete lock acquisition
- * @lock: the rt_mutex we were woken on
- * @to: the timeout, null if none. hrtimer should already have
- * been started.
- * @waiter: the pre-initialized rt_mutex_waiter
- * @detect_deadlock: perform deadlock detection (1) or not (0)
- *
- * Complete the lock acquisition started our behalf by another thread.
- *
- * Returns:
- * 0 - success
- * <0 - error, one of -EINTR, -ETIMEDOUT, or -EDEADLK
- *
- * Special API call for PI-futex requeue support
- */
-int rt_mutex_finish_proxy_lock(struct rt_mutex *lock,
- struct hrtimer_sleeper *to,
- struct rt_mutex_waiter *waiter,
- int detect_deadlock)
-{
- int ret;
-
- raw_spin_lock(&lock->wait_lock);
-
- set_current_state(TASK_INTERRUPTIBLE);
-
- ret = __rt_mutex_slowlock(lock, TASK_INTERRUPTIBLE, to, waiter);
-
- set_current_state(TASK_RUNNING);
-
- if (unlikely(ret))
- remove_waiter(lock, waiter);
-
- /*
- * try_to_take_rt_mutex() sets the waiter bit unconditionally. We might
- * have to fix that up.
- */
- fixup_rt_mutex_waiters(lock);
-
- raw_spin_unlock(&lock->wait_lock);
-
- return ret;
-}
+++ /dev/null
-/*
- * RT-Mutexes: blocking mutual exclusion locks with PI support
- *
- * started by Ingo Molnar and Thomas Gleixner:
- *
- * Copyright (C) 2004-2006 Red Hat, Inc., Ingo Molnar <mingo@redhat.com>
- * Copyright (C) 2006, Timesys Corp., Thomas Gleixner <tglx@timesys.com>
- *
- * This file contains macros used solely by rtmutex.c.
- * Non-debug version.
- */
-
-#define rt_mutex_deadlock_check(l) (0)
-#define rt_mutex_deadlock_account_lock(m, t) do { } while (0)
-#define rt_mutex_deadlock_account_unlock(l) do { } while (0)
-#define debug_rt_mutex_init_waiter(w) do { } while (0)
-#define debug_rt_mutex_free_waiter(w) do { } while (0)
-#define debug_rt_mutex_lock(l) do { } while (0)
-#define debug_rt_mutex_proxy_lock(l,p) do { } while (0)
-#define debug_rt_mutex_proxy_unlock(l) do { } while (0)
-#define debug_rt_mutex_unlock(l) do { } while (0)
-#define debug_rt_mutex_init(m, n) do { } while (0)
-#define debug_rt_mutex_deadlock(d, a ,l) do { } while (0)
-#define debug_rt_mutex_print_deadlock(w) do { } while (0)
-#define debug_rt_mutex_detect_deadlock(w,d) (d)
-#define debug_rt_mutex_reset_waiter(w) do { } while (0)
+++ /dev/null
-/*
- * RT Mutexes: blocking mutual exclusion locks with PI support
- *
- * started by Ingo Molnar and Thomas Gleixner:
- *
- * Copyright (C) 2004-2006 Red Hat, Inc., Ingo Molnar <mingo@redhat.com>
- * Copyright (C) 2006, Timesys Corp., Thomas Gleixner <tglx@timesys.com>
- *
- * This file contains the private data structure and API definitions.
- */
-
-#ifndef __KERNEL_RTMUTEX_COMMON_H
-#define __KERNEL_RTMUTEX_COMMON_H
-
-#include <linux/rtmutex.h>
-
-/*
- * The rtmutex in kernel tester is independent of rtmutex debugging. We
- * call schedule_rt_mutex_test() instead of schedule() for the tasks which
- * belong to the tester. That way we can delay the wakeup path of those
- * threads to provoke lock stealing and testing of complex boosting scenarios.
- */
-#ifdef CONFIG_RT_MUTEX_TESTER
-
-extern void schedule_rt_mutex_test(struct rt_mutex *lock);
-
-#define schedule_rt_mutex(_lock) \
- do { \
- if (!(current->flags & PF_MUTEX_TESTER)) \
- schedule(); \
- else \
- schedule_rt_mutex_test(_lock); \
- } while (0)
-
-#else
-# define schedule_rt_mutex(_lock) schedule()
-#endif
-
-/*
- * This is the control structure for tasks blocked on a rt_mutex,
- * which is allocated on the kernel stack on of the blocked task.
- *
- * @list_entry: pi node to enqueue into the mutex waiters list
- * @pi_list_entry: pi node to enqueue into the mutex owner waiters list
- * @task: task reference to the blocked task
- */
-struct rt_mutex_waiter {
- struct plist_node list_entry;
- struct plist_node pi_list_entry;
- struct task_struct *task;
- struct rt_mutex *lock;
-#ifdef CONFIG_DEBUG_RT_MUTEXES
- unsigned long ip;
- struct pid *deadlock_task_pid;
- struct rt_mutex *deadlock_lock;
-#endif
-};
-
-/*
- * Various helpers to access the waiters-plist:
- */
-static inline int rt_mutex_has_waiters(struct rt_mutex *lock)
-{
- return !plist_head_empty(&lock->wait_list);
-}
-
-static inline struct rt_mutex_waiter *
-rt_mutex_top_waiter(struct rt_mutex *lock)
-{
- struct rt_mutex_waiter *w;
-
- w = plist_first_entry(&lock->wait_list, struct rt_mutex_waiter,
- list_entry);
- BUG_ON(w->lock != lock);
-
- return w;
-}
-
-static inline int task_has_pi_waiters(struct task_struct *p)
-{
- return !plist_head_empty(&p->pi_waiters);
-}
-
-static inline struct rt_mutex_waiter *
-task_top_pi_waiter(struct task_struct *p)
-{
- return plist_first_entry(&p->pi_waiters, struct rt_mutex_waiter,
- pi_list_entry);
-}
-
-/*
- * lock->owner state tracking:
- */
-#define RT_MUTEX_HAS_WAITERS 1UL
-#define RT_MUTEX_OWNER_MASKALL 1UL
-
-static inline struct task_struct *rt_mutex_owner(struct rt_mutex *lock)
-{
- return (struct task_struct *)
- ((unsigned long)lock->owner & ~RT_MUTEX_OWNER_MASKALL);
-}
-
-/*
- * PI-futex support (proxy locking functions, etc.):
- */
-extern struct task_struct *rt_mutex_next_owner(struct rt_mutex *lock);
-extern void rt_mutex_init_proxy_locked(struct rt_mutex *lock,
- struct task_struct *proxy_owner);
-extern void rt_mutex_proxy_unlock(struct rt_mutex *lock,
- struct task_struct *proxy_owner);
-extern int rt_mutex_start_proxy_lock(struct rt_mutex *lock,
- struct rt_mutex_waiter *waiter,
- struct task_struct *task,
- int detect_deadlock);
-extern int rt_mutex_finish_proxy_lock(struct rt_mutex *lock,
- struct hrtimer_sleeper *to,
- struct rt_mutex_waiter *waiter,
- int detect_deadlock);
-
-#ifdef CONFIG_DEBUG_RT_MUTEXES
-# include "rtmutex-debug.h"
-#else
-# include "rtmutex.h"
-#endif
-
-#endif
projects / GitHub / moto-9609 / android_kernel_motorola_exynos9610.git / commitdiff