diff --git a/arch/alpha/Kconfig b/arch/alpha/Kconfig index 0c4805a572c8..04a4a138ed13 100644 --- a/arch/alpha/Kconfig +++ b/arch/alpha/Kconfig @@ -555,11 +555,6 @@ config SMP If you don't know what to do here, say N. -config HAVE_DEC_LOCK - bool - depends on SMP - default y - config NR_CPUS int "Maximum number of CPUs (2-32)" range 2 32 diff --git a/arch/alpha/lib/Makefile b/arch/alpha/lib/Makefile index 04f9729de57c..854d5e79979e 100644 --- a/arch/alpha/lib/Makefile +++ b/arch/alpha/lib/Makefile @@ -35,8 +35,6 @@ lib-y = __divqu.o __remqu.o __divlu.o __remlu.o \ callback_srm.o srm_puts.o srm_printk.o \ fls.o -lib-$(CONFIG_SMP) += dec_and_lock.o - # The division routines are built from single source, with different defines. AFLAGS___divqu.o = -DDIV AFLAGS___remqu.o = -DREM diff --git a/arch/alpha/lib/dec_and_lock.c b/arch/alpha/lib/dec_and_lock.c deleted file mode 100644 index a117707f57fe..000000000000 --- a/arch/alpha/lib/dec_and_lock.c +++ /dev/null @@ -1,44 +0,0 @@ -// SPDX-License-Identifier: GPL-2.0 -/* - * arch/alpha/lib/dec_and_lock.c - * - * ll/sc version of atomic_dec_and_lock() - * - */ - -#include -#include -#include - - asm (".text \n\ - .global _atomic_dec_and_lock \n\ - .ent _atomic_dec_and_lock \n\ - .align 4 \n\ -_atomic_dec_and_lock: \n\ - .prologue 0 \n\ -1: ldl_l $1, 0($16) \n\ - subl $1, 1, $1 \n\ - beq $1, 2f \n\ - stl_c $1, 0($16) \n\ - beq $1, 4f \n\ - mb \n\ - clr $0 \n\ - ret \n\ -2: br $29, 3f \n\ -3: ldgp $29, 0($29) \n\ - br $atomic_dec_and_lock_1..ng \n\ - .subsection 2 \n\ -4: br 1b \n\ - .previous \n\ - .end _atomic_dec_and_lock"); - -static int __used atomic_dec_and_lock_1(atomic_t *atomic, spinlock_t *lock) -{ - /* Slow path */ - spin_lock(lock); - if (atomic_dec_and_test(atomic)) - return 1; - spin_unlock(lock); - return 0; -} -EXPORT_SYMBOL(_atomic_dec_and_lock); diff --git a/include/asm-generic/qspinlock_types.h b/include/asm-generic/qspinlock_types.h index 0763f065b975..d10f1e7d6ba8 100644 --- a/include/asm-generic/qspinlock_types.h +++ b/include/asm-generic/qspinlock_types.h @@ -63,7 +63,7 @@ typedef struct qspinlock { /* * Initializier */ -#define __ARCH_SPIN_LOCK_UNLOCKED { .val = ATOMIC_INIT(0) } +#define __ARCH_SPIN_LOCK_UNLOCKED { { .val = ATOMIC_INIT(0) } } /* * Bitfields in the atomic value: diff --git a/include/linux/refcount.h b/include/linux/refcount.h index 4193c41e383a..a685da2c4522 100644 --- a/include/linux/refcount.h +++ b/include/linux/refcount.h @@ -98,5 +98,7 @@ extern __must_check bool refcount_dec_if_one(refcount_t *r); extern __must_check bool refcount_dec_not_one(refcount_t *r); extern __must_check bool refcount_dec_and_mutex_lock(refcount_t *r, struct mutex *lock); extern __must_check bool refcount_dec_and_lock(refcount_t *r, spinlock_t *lock); - +extern __must_check bool refcount_dec_and_lock_irqsave(refcount_t *r, + spinlock_t *lock, + unsigned long *flags); #endif /* _LINUX_REFCOUNT_H */ diff --git a/include/linux/spinlock.h b/include/linux/spinlock.h index 1e8a46435838..fd57888d4942 100644 --- a/include/linux/spinlock.h +++ b/include/linux/spinlock.h @@ -427,6 +427,11 @@ extern int _atomic_dec_and_lock(atomic_t *atomic, spinlock_t *lock); #define atomic_dec_and_lock(atomic, lock) \ __cond_lock(lock, _atomic_dec_and_lock(atomic, lock)) +extern int _atomic_dec_and_lock_irqsave(atomic_t *atomic, spinlock_t *lock, + unsigned long *flags); +#define atomic_dec_and_lock_irqsave(atomic, lock, flags) \ + __cond_lock(lock, _atomic_dec_and_lock_irqsave(atomic, lock, &(flags))) + int alloc_bucket_spinlocks(spinlock_t **locks, unsigned int *lock_mask, size_t max_size, unsigned int cpu_mult, gfp_t gfp); diff --git a/kernel/locking/lockdep.c b/kernel/locking/lockdep.c index edcac5de7ebc..5fa4d3138bf1 100644 --- a/kernel/locking/lockdep.c +++ b/kernel/locking/lockdep.c @@ -1265,11 +1265,11 @@ unsigned long lockdep_count_forward_deps(struct lock_class *class) this.parent = NULL; this.class = class; - local_irq_save(flags); + raw_local_irq_save(flags); arch_spin_lock(&lockdep_lock); ret = __lockdep_count_forward_deps(&this); arch_spin_unlock(&lockdep_lock); - local_irq_restore(flags); + raw_local_irq_restore(flags); return ret; } @@ -1292,11 +1292,11 @@ unsigned long lockdep_count_backward_deps(struct lock_class *class) this.parent = NULL; this.class = class; - local_irq_save(flags); + raw_local_irq_save(flags); arch_spin_lock(&lockdep_lock); ret = __lockdep_count_backward_deps(&this); arch_spin_unlock(&lockdep_lock); - local_irq_restore(flags); + raw_local_irq_restore(flags); return ret; } @@ -4411,7 +4411,7 @@ void debug_check_no_locks_freed(const void *mem_from, unsigned long mem_len) if (unlikely(!debug_locks)) return; - local_irq_save(flags); + raw_local_irq_save(flags); for (i = 0; i < curr->lockdep_depth; i++) { hlock = curr->held_locks + i; @@ -4422,7 +4422,7 @@ void debug_check_no_locks_freed(const void *mem_from, unsigned long mem_len) print_freed_lock_bug(curr, mem_from, mem_from + mem_len, hlock); break; } - local_irq_restore(flags); + raw_local_irq_restore(flags); } EXPORT_SYMBOL_GPL(debug_check_no_locks_freed); diff --git a/kernel/locking/rwsem.c b/kernel/locking/rwsem.c index bc1e507be9ff..776308d2fa9e 100644 --- a/kernel/locking/rwsem.c +++ b/kernel/locking/rwsem.c @@ -181,6 +181,7 @@ void down_read_non_owner(struct rw_semaphore *sem) might_sleep(); __down_read(sem); + rwsem_set_reader_owned(sem); } EXPORT_SYMBOL(down_read_non_owner); diff --git a/lib/Makefile b/lib/Makefile index 8153fdab287f..90dc5520b784 100644 --- a/lib/Makefile +++ b/lib/Makefile @@ -23,7 +23,7 @@ lib-y := ctype.o string.o vsprintf.o cmdline.o \ sha1.o chacha20.o irq_regs.o argv_split.o \ flex_proportions.o ratelimit.o show_mem.o \ is_single_threaded.o plist.o decompress.o kobject_uevent.o \ - earlycpio.o seq_buf.o siphash.o \ + earlycpio.o seq_buf.o siphash.o dec_and_lock.o \ nmi_backtrace.o nodemask.o win_minmax.o lib-$(CONFIG_PRINTK) += dump_stack.o @@ -95,10 +95,6 @@ obj-$(CONFIG_DEBUG_PREEMPT) += smp_processor_id.o obj-$(CONFIG_DEBUG_LIST) += list_debug.o obj-$(CONFIG_DEBUG_OBJECTS) += debugobjects.o -ifneq ($(CONFIG_HAVE_DEC_LOCK),y) - lib-y += dec_and_lock.o -endif - obj-$(CONFIG_BITREVERSE) += bitrev.o obj-$(CONFIG_RATIONAL) += rational.o obj-$(CONFIG_CRC_CCITT) += crc-ccitt.o diff --git a/lib/dec_and_lock.c b/lib/dec_and_lock.c index 347fa7ac2e8a..9555b68bb774 100644 --- a/lib/dec_and_lock.c +++ b/lib/dec_and_lock.c @@ -33,3 +33,19 @@ int _atomic_dec_and_lock(atomic_t *atomic, spinlock_t *lock) } EXPORT_SYMBOL(_atomic_dec_and_lock); + +int _atomic_dec_and_lock_irqsave(atomic_t *atomic, spinlock_t *lock, + unsigned long *flags) +{ + /* Subtract 1 from counter unless that drops it to 0 (ie. it was 1) */ + if (atomic_add_unless(atomic, -1, 1)) + return 0; + + /* Otherwise do it the slow way */ + spin_lock_irqsave(lock, *flags); + if (atomic_dec_and_test(atomic)) + return 1; + spin_unlock_irqrestore(lock, *flags); + return 0; +} +EXPORT_SYMBOL(_atomic_dec_and_lock_irqsave); diff --git a/lib/refcount.c b/lib/refcount.c index 0eb48353abe3..d3b81cefce91 100644 --- a/lib/refcount.c +++ b/lib/refcount.c @@ -350,3 +350,31 @@ bool refcount_dec_and_lock(refcount_t *r, spinlock_t *lock) } EXPORT_SYMBOL(refcount_dec_and_lock); +/** + * refcount_dec_and_lock_irqsave - return holding spinlock with disabled + * interrupts if able to decrement refcount to 0 + * @r: the refcount + * @lock: the spinlock to be locked + * @flags: saved IRQ-flags if the is acquired + * + * Same as refcount_dec_and_lock() above except that the spinlock is acquired + * with disabled interupts. + * + * Return: true and hold spinlock if able to decrement refcount to 0, false + * otherwise + */ +bool refcount_dec_and_lock_irqsave(refcount_t *r, spinlock_t *lock, + unsigned long *flags) +{ + if (refcount_dec_not_one(r)) + return false; + + spin_lock_irqsave(lock, *flags); + if (!refcount_dec_and_test(r)) { + spin_unlock_irqrestore(lock, *flags); + return false; + } + + return true; +} +EXPORT_SYMBOL(refcount_dec_and_lock_irqsave);