diff options
author | Keir Fraser <keir@xen.org> | 2010-11-18 11:45:33 +0000 |
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committer | Keir Fraser <keir@xen.org> | 2010-11-18 11:45:33 +0000 |
commit | 652ec2d1ec8c2c79dce01dc9136c0dfefeabc13e (patch) | |
tree | 5c31a11a97e5c3143712dd2c4dfc2e3da5a38505 /xen | |
parent | c03ec255cdfe2ee762e27be80132ee240be50314 (diff) | |
download | xen-652ec2d1ec8c2c79dce01dc9136c0dfefeabc13e.tar.gz xen-652ec2d1ec8c2c79dce01dc9136c0dfefeabc13e.tar.bz2 xen-652ec2d1ec8c2c79dce01dc9136c0dfefeabc13e.zip |
Define Linux-style <preempt.h> interface.
Use it to disable sleeping in spinlock and rcu-read regions.
Signed-off-by: Keir Fraser <keir@xen.org>
Diffstat (limited to 'xen')
-rw-r--r-- | xen/common/Makefile | 1 | ||||
-rw-r--r-- | xen/common/preempt.c | 25 | ||||
-rw-r--r-- | xen/common/schedule.c | 1 | ||||
-rw-r--r-- | xen/common/softirq.c | 1 | ||||
-rw-r--r-- | xen/common/spinlock.c | 54 | ||||
-rw-r--r-- | xen/include/xen/lib.h | 2 | ||||
-rw-r--r-- | xen/include/xen/preempt.h | 33 | ||||
-rw-r--r-- | xen/include/xen/rcupdate.h | 5 | ||||
-rw-r--r-- | xen/include/xen/spinlock.h | 2 |
9 files changed, 85 insertions, 39 deletions
diff --git a/xen/common/Makefile b/xen/common/Makefile index 1abca7d64a..d244e39c31 100644 --- a/xen/common/Makefile +++ b/xen/common/Makefile @@ -13,6 +13,7 @@ obj-y += memory.o obj-y += multicall.o obj-y += notifier.o obj-y += page_alloc.o +obj-y += preempt.o obj-y += rangeset.o obj-y += sched_credit.o obj-y += sched_credit2.o diff --git a/xen/common/preempt.c b/xen/common/preempt.c new file mode 100644 index 0000000000..e2133ea50a --- /dev/null +++ b/xen/common/preempt.c @@ -0,0 +1,25 @@ +/****************************************************************************** + * preempt.c + * + * Track atomic regions in the hypervisor which disallow sleeping. + * + * Copyright (c) 2010, Keir Fraser <keir@xen.org> + * + * This program is free software; you can redistribute it and/or modify + * it under the terms of the GNU General Public License as published by + * the Free Software Foundation; either version 2 of the License, or + * (at your option) any later version. + * + * This program is distributed in the hope that it will be useful, + * but WITHOUT ANY WARRANTY; without even the implied warranty of + * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the + * GNU General Public License for more details. + * + * You should have received a copy of the GNU General Public License + * along with this program; if not, write to the Free Software + * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA + */ + +#include <xen/preempt.h> + +DEFINE_PER_CPU(unsigned int, __preempt_count); diff --git a/xen/common/schedule.c b/xen/common/schedule.c index 5e86082b15..2415ce1554 100644 --- a/xen/common/schedule.c +++ b/xen/common/schedule.c @@ -32,6 +32,7 @@ #include <xen/guest_access.h> #include <xen/multicall.h> #include <xen/cpu.h> +#include <xen/preempt.h> #include <public/sched.h> #include <xsm/xsm.h> diff --git a/xen/common/softirq.c b/xen/common/softirq.c index fb5fcd147d..30559ce7b2 100644 --- a/xen/common/softirq.c +++ b/xen/common/softirq.c @@ -12,6 +12,7 @@ #include <xen/config.h> #include <xen/init.h> #include <xen/mm.h> +#include <xen/preempt.h> #include <xen/sched.h> #include <xen/rcupdate.h> #include <xen/softirq.h> diff --git a/xen/common/spinlock.c b/xen/common/spinlock.c index fff796171d..2abf89e9b1 100644 --- a/xen/common/spinlock.c +++ b/xen/common/spinlock.c @@ -5,6 +5,7 @@ #include <xen/time.h> #include <xen/spinlock.h> #include <xen/guest_access.h> +#include <xen/preempt.h> #include <public/sysctl.h> #include <asm/processor.h> @@ -39,22 +40,9 @@ void spin_debug_disable(void) atomic_dec(&spin_debug); } -static DEFINE_PER_CPU(atomic_t, lockdepth); - -#define lockdepth_inc() atomic_inc(&this_cpu(lockdepth)) -#define lockdepth_dec() atomic_dec(&this_cpu(lockdepth)) - -unsigned int locking_depth(void) -{ - return atomic_read(&this_cpu(lockdepth)); -} - #else /* defined(NDEBUG) */ #define check_lock(l) ((void)0) -#define lockdepth_inc() ((void)0) -#define lockdepth_dec() ((void)0) -unsigned int locking_depth(void) { return 0; } #endif @@ -94,7 +82,7 @@ void _spin_lock(spinlock_t *lock) cpu_relax(); } LOCK_PROFILE_GOT; - lockdepth_inc(); + preempt_disable(); } void _spin_lock_irq(spinlock_t *lock) @@ -113,7 +101,7 @@ void _spin_lock_irq(spinlock_t *lock) local_irq_disable(); } LOCK_PROFILE_GOT; - lockdepth_inc(); + preempt_disable(); } unsigned long _spin_lock_irqsave(spinlock_t *lock) @@ -132,20 +120,20 @@ unsigned long _spin_lock_irqsave(spinlock_t *lock) local_irq_save(flags); } LOCK_PROFILE_GOT; - lockdepth_inc(); + preempt_disable(); return flags; } void _spin_unlock(spinlock_t *lock) { - lockdepth_dec(); + preempt_enable(); LOCK_PROFILE_REL; _raw_spin_unlock(&lock->raw); } void _spin_unlock_irq(spinlock_t *lock) { - lockdepth_dec(); + preempt_enable(); LOCK_PROFILE_REL; _raw_spin_unlock(&lock->raw); local_irq_enable(); @@ -153,7 +141,7 @@ void _spin_unlock_irq(spinlock_t *lock) void _spin_unlock_irqrestore(spinlock_t *lock, unsigned long flags) { - lockdepth_dec(); + preempt_enable(); LOCK_PROFILE_REL; _raw_spin_unlock(&lock->raw); local_irq_restore(flags); @@ -173,7 +161,7 @@ int _spin_trylock(spinlock_t *lock) #ifdef LOCK_PROFILE lock->profile.time_locked = NOW(); #endif - lockdepth_inc(); + preempt_disable(); return 1; } @@ -247,7 +235,7 @@ void _read_lock(rwlock_t *lock) { check_lock(&lock->debug); _raw_read_lock(&lock->raw); - lockdepth_inc(); + preempt_disable(); } void _read_lock_irq(rwlock_t *lock) @@ -256,7 +244,7 @@ void _read_lock_irq(rwlock_t *lock) local_irq_disable(); check_lock(&lock->debug); _raw_read_lock(&lock->raw); - lockdepth_inc(); + preempt_disable(); } unsigned long _read_lock_irqsave(rwlock_t *lock) @@ -265,26 +253,26 @@ unsigned long _read_lock_irqsave(rwlock_t *lock) local_irq_save(flags); check_lock(&lock->debug); _raw_read_lock(&lock->raw); - lockdepth_inc(); + preempt_disable(); return flags; } void _read_unlock(rwlock_t *lock) { - lockdepth_dec(); + preempt_enable(); _raw_read_unlock(&lock->raw); } void _read_unlock_irq(rwlock_t *lock) { - lockdepth_dec(); + preempt_enable(); _raw_read_unlock(&lock->raw); local_irq_enable(); } void _read_unlock_irqrestore(rwlock_t *lock, unsigned long flags) { - lockdepth_dec(); + preempt_enable(); _raw_read_unlock(&lock->raw); local_irq_restore(flags); } @@ -293,7 +281,7 @@ void _write_lock(rwlock_t *lock) { check_lock(&lock->debug); _raw_write_lock(&lock->raw); - lockdepth_inc(); + preempt_disable(); } void _write_lock_irq(rwlock_t *lock) @@ -302,7 +290,7 @@ void _write_lock_irq(rwlock_t *lock) local_irq_disable(); check_lock(&lock->debug); _raw_write_lock(&lock->raw); - lockdepth_inc(); + preempt_disable(); } unsigned long _write_lock_irqsave(rwlock_t *lock) @@ -311,7 +299,7 @@ unsigned long _write_lock_irqsave(rwlock_t *lock) local_irq_save(flags); check_lock(&lock->debug); _raw_write_lock(&lock->raw); - lockdepth_inc(); + preempt_disable(); return flags; } @@ -320,26 +308,26 @@ int _write_trylock(rwlock_t *lock) check_lock(&lock->debug); if ( !_raw_write_trylock(&lock->raw) ) return 0; - lockdepth_inc(); + preempt_disable(); return 1; } void _write_unlock(rwlock_t *lock) { - lockdepth_dec(); + preempt_enable(); _raw_write_unlock(&lock->raw); } void _write_unlock_irq(rwlock_t *lock) { - lockdepth_dec(); + preempt_enable(); _raw_write_unlock(&lock->raw); local_irq_enable(); } void _write_unlock_irqrestore(rwlock_t *lock, unsigned long flags) { - lockdepth_dec(); + preempt_enable(); _raw_write_unlock(&lock->raw); local_irq_restore(flags); } diff --git a/xen/include/xen/lib.h b/xen/include/xen/lib.h index a5a27d58ab..e09929a604 100644 --- a/xen/include/xen/lib.h +++ b/xen/include/xen/lib.h @@ -119,6 +119,4 @@ extern void add_taint(unsigned); struct cpu_user_regs; void dump_execstate(struct cpu_user_regs *); -#define in_atomic() (locking_depth() || in_irq() || !local_irq_is_enabled()) - #endif /* __LIB_H__ */ diff --git a/xen/include/xen/preempt.h b/xen/include/xen/preempt.h new file mode 100644 index 0000000000..749bc589cb --- /dev/null +++ b/xen/include/xen/preempt.h @@ -0,0 +1,33 @@ +/****************************************************************************** + * preempt.h + * + * Track atomic regions in the hypervisor which disallow sleeping. + * + * Copyright (c) 2010, Keir Fraser <keir@xen.org> + */ + +#ifndef __XEN_PREEMPT_H__ +#define __XEN_PREEMPT_H__ + +#include <xen/config.h> +#include <xen/percpu.h> +#include <xen/irq.h> /* in_irq() */ +#include <asm/system.h> /* local_irq_is_enabled() */ + +DECLARE_PER_CPU(unsigned int, __preempt_count); + +#define preempt_count() (this_cpu(__preempt_count)) + +#define preempt_disable() do { \ + preempt_count()++; \ + barrier(); \ +} while (0) + +#define preempt_enable() do { \ + barrier(); \ + preempt_count()--; \ +} while (0) + +#define in_atomic() (preempt_count() || in_irq() || !local_irq_is_enabled()) + +#endif /* __XEN_PREEMPT_H__ */ diff --git a/xen/include/xen/rcupdate.h b/xen/include/xen/rcupdate.h index 68f98acfda..bb4af9d6e0 100644 --- a/xen/include/xen/rcupdate.h +++ b/xen/include/xen/rcupdate.h @@ -36,6 +36,7 @@ #include <xen/spinlock.h> #include <xen/percpu.h> #include <xen/cpumask.h> +#include <xen/preempt.h> /** * struct rcu_head - callback structure for use with RCU @@ -145,14 +146,14 @@ typedef struct _rcu_read_lock rcu_read_lock_t; * * It is illegal to block while in an RCU read-side critical section. */ -#define rcu_read_lock(x) ((void)(x)) +#define rcu_read_lock(x) ({ ((void)(x)); preempt_disable(); }) /** * rcu_read_unlock - marks the end of an RCU read-side critical section. * * See rcu_read_lock() for more information. */ -#define rcu_read_unlock(x) ((void)(x)) +#define rcu_read_unlock(x) ({ ((void)(x)); preempt_enable(); }) /* * So where is rcu_write_lock()? It does not exist, as there is no diff --git a/xen/include/xen/spinlock.h b/xen/include/xen/spinlock.h index 6bb0cd6d1c..a2d1ed99bf 100644 --- a/xen/include/xen/spinlock.h +++ b/xen/include/xen/spinlock.h @@ -223,6 +223,4 @@ int _rw_is_write_locked(rwlock_t *lock); #define rw_is_locked(l) _rw_is_locked(l) #define rw_is_write_locked(l) _rw_is_write_locked(l) -unsigned int locking_depth(void); - #endif /* __SPINLOCK_H__ */ |