diff --git a/MAINTAINERS b/MAINTAINERS index 43b36dbed48e..8876f5de7738 100644 --- a/MAINTAINERS +++ b/MAINTAINERS @@ -9098,7 +9098,6 @@ F: arch/*/include/asm/spinlock*.h F: include/linux/rwlock*.h F: include/linux/mutex*.h F: include/linux/rwsem*.h -F: arch/*/include/asm/rwsem.h F: include/linux/seqlock.h F: lib/locking*.[ch] F: kernel/locking/ diff --git a/arch/alpha/include/asm/rwsem.h b/arch/alpha/include/asm/rwsem.h deleted file mode 100644 index cf8fc8f9a2ed..000000000000 --- a/arch/alpha/include/asm/rwsem.h +++ /dev/null @@ -1,211 +0,0 @@ -/* SPDX-License-Identifier: GPL-2.0 */ -#ifndef _ALPHA_RWSEM_H -#define _ALPHA_RWSEM_H - -/* - * Written by Ivan Kokshaysky , 2001. - * Based on asm-alpha/semaphore.h and asm-i386/rwsem.h - */ - -#ifndef _LINUX_RWSEM_H -#error "please don't include asm/rwsem.h directly, use linux/rwsem.h instead" -#endif - -#ifdef __KERNEL__ - -#include - -#define RWSEM_UNLOCKED_VALUE 0x0000000000000000L -#define RWSEM_ACTIVE_BIAS 0x0000000000000001L -#define RWSEM_ACTIVE_MASK 0x00000000ffffffffL -#define RWSEM_WAITING_BIAS (-0x0000000100000000L) -#define RWSEM_ACTIVE_READ_BIAS RWSEM_ACTIVE_BIAS -#define RWSEM_ACTIVE_WRITE_BIAS (RWSEM_WAITING_BIAS + RWSEM_ACTIVE_BIAS) - -static inline int ___down_read(struct rw_semaphore *sem) -{ - long oldcount; -#ifndef CONFIG_SMP - oldcount = sem->count.counter; - sem->count.counter += RWSEM_ACTIVE_READ_BIAS; -#else - long temp; - __asm__ __volatile__( - "1: ldq_l %0,%1\n" - " addq %0,%3,%2\n" - " stq_c %2,%1\n" - " beq %2,2f\n" - " mb\n" - ".subsection 2\n" - "2: br 1b\n" - ".previous" - :"=&r" (oldcount), "=m" (sem->count), "=&r" (temp) - :"Ir" (RWSEM_ACTIVE_READ_BIAS), "m" (sem->count) : "memory"); -#endif - return (oldcount < 0); -} - -static inline void __down_read(struct rw_semaphore *sem) -{ - if (unlikely(___down_read(sem))) - rwsem_down_read_failed(sem); -} - -static inline int __down_read_killable(struct rw_semaphore *sem) -{ - if (unlikely(___down_read(sem))) - if (IS_ERR(rwsem_down_read_failed_killable(sem))) - return -EINTR; - - return 0; -} - -/* - * trylock for reading -- returns 1 if successful, 0 if contention - */ -static inline int __down_read_trylock(struct rw_semaphore *sem) -{ - long old, new, res; - - res = atomic_long_read(&sem->count); - do { - new = res + RWSEM_ACTIVE_READ_BIAS; - if (new <= 0) - break; - old = res; - res = atomic_long_cmpxchg(&sem->count, old, new); - } while (res != old); - return res >= 0 ? 1 : 0; -} - -static inline long ___down_write(struct rw_semaphore *sem) -{ - long oldcount; -#ifndef CONFIG_SMP - oldcount = sem->count.counter; - sem->count.counter += RWSEM_ACTIVE_WRITE_BIAS; -#else - long temp; - __asm__ __volatile__( - "1: ldq_l %0,%1\n" - " addq %0,%3,%2\n" - " stq_c %2,%1\n" - " beq %2,2f\n" - " mb\n" - ".subsection 2\n" - "2: br 1b\n" - ".previous" - :"=&r" (oldcount), "=m" (sem->count), "=&r" (temp) - :"Ir" (RWSEM_ACTIVE_WRITE_BIAS), "m" (sem->count) : "memory"); -#endif - return oldcount; -} - -static inline void __down_write(struct rw_semaphore *sem) -{ - if (unlikely(___down_write(sem))) - rwsem_down_write_failed(sem); -} - -static inline int __down_write_killable(struct rw_semaphore *sem) -{ - if (unlikely(___down_write(sem))) { - if (IS_ERR(rwsem_down_write_failed_killable(sem))) - return -EINTR; - } - - return 0; -} - -/* - * trylock for writing -- returns 1 if successful, 0 if contention - */ -static inline int __down_write_trylock(struct rw_semaphore *sem) -{ - long ret = atomic_long_cmpxchg(&sem->count, RWSEM_UNLOCKED_VALUE, - RWSEM_ACTIVE_WRITE_BIAS); - if (ret == RWSEM_UNLOCKED_VALUE) - return 1; - return 0; -} - -static inline void __up_read(struct rw_semaphore *sem) -{ - long oldcount; -#ifndef CONFIG_SMP - oldcount = sem->count.counter; - sem->count.counter -= RWSEM_ACTIVE_READ_BIAS; -#else - long temp; - __asm__ __volatile__( - " mb\n" - "1: ldq_l %0,%1\n" - " subq %0,%3,%2\n" - " stq_c %2,%1\n" - " beq %2,2f\n" - ".subsection 2\n" - "2: br 1b\n" - ".previous" - :"=&r" (oldcount), "=m" (sem->count), "=&r" (temp) - :"Ir" (RWSEM_ACTIVE_READ_BIAS), "m" (sem->count) : "memory"); -#endif - if (unlikely(oldcount < 0)) - if ((int)oldcount - RWSEM_ACTIVE_READ_BIAS == 0) - rwsem_wake(sem); -} - -static inline void __up_write(struct rw_semaphore *sem) -{ - long count; -#ifndef CONFIG_SMP - sem->count.counter -= RWSEM_ACTIVE_WRITE_BIAS; - count = sem->count.counter; -#else - long temp; - __asm__ __volatile__( - " mb\n" - "1: ldq_l %0,%1\n" - " subq %0,%3,%2\n" - " stq_c %2,%1\n" - " beq %2,2f\n" - " subq %0,%3,%0\n" - ".subsection 2\n" - "2: br 1b\n" - ".previous" - :"=&r" (count), "=m" (sem->count), "=&r" (temp) - :"Ir" (RWSEM_ACTIVE_WRITE_BIAS), "m" (sem->count) : "memory"); -#endif - if (unlikely(count)) - if ((int)count == 0) - rwsem_wake(sem); -} - -/* - * downgrade write lock to read lock - */ -static inline void __downgrade_write(struct rw_semaphore *sem) -{ - long oldcount; -#ifndef CONFIG_SMP - oldcount = sem->count.counter; - sem->count.counter -= RWSEM_WAITING_BIAS; -#else - long temp; - __asm__ __volatile__( - "1: ldq_l %0,%1\n" - " addq %0,%3,%2\n" - " stq_c %2,%1\n" - " beq %2,2f\n" - " mb\n" - ".subsection 2\n" - "2: br 1b\n" - ".previous" - :"=&r" (oldcount), "=m" (sem->count), "=&r" (temp) - :"Ir" (-RWSEM_WAITING_BIAS), "m" (sem->count) : "memory"); -#endif - if (unlikely(oldcount < 0)) - rwsem_downgrade_wake(sem); -} - -#endif /* __KERNEL__ */ -#endif /* _ALPHA_RWSEM_H */ diff --git a/arch/arm/include/asm/Kbuild b/arch/arm/include/asm/Kbuild index a8a4eb7f6dae..8fb51b7bf1d5 100644 --- a/arch/arm/include/asm/Kbuild +++ b/arch/arm/include/asm/Kbuild @@ -12,7 +12,6 @@ generic-y += mm-arch-hooks.h generic-y += msi.h generic-y += parport.h generic-y += preempt.h -generic-y += rwsem.h generic-y += seccomp.h generic-y += segment.h generic-y += serial.h diff --git a/arch/arm64/include/asm/Kbuild b/arch/arm64/include/asm/Kbuild index 1e17ea5c372b..60a933b07001 100644 --- a/arch/arm64/include/asm/Kbuild +++ b/arch/arm64/include/asm/Kbuild @@ -16,7 +16,6 @@ generic-y += mm-arch-hooks.h generic-y += msi.h generic-y += qrwlock.h generic-y += qspinlock.h -generic-y += rwsem.h generic-y += segment.h generic-y += serial.h generic-y += set_memory.h diff --git a/arch/hexagon/include/asm/Kbuild b/arch/hexagon/include/asm/Kbuild index d046e8ccdf78..3ff5f297acda 100644 --- a/arch/hexagon/include/asm/Kbuild +++ b/arch/hexagon/include/asm/Kbuild @@ -27,7 +27,6 @@ generic-y += mm-arch-hooks.h generic-y += pci.h generic-y += percpu.h generic-y += preempt.h -generic-y += rwsem.h generic-y += sections.h generic-y += segment.h generic-y += serial.h diff --git a/arch/ia64/include/asm/rwsem.h b/arch/ia64/include/asm/rwsem.h deleted file mode 100644 index 917910607e0e..000000000000 --- a/arch/ia64/include/asm/rwsem.h +++ /dev/null @@ -1,172 +0,0 @@ -/* SPDX-License-Identifier: GPL-2.0 */ -/* - * R/W semaphores for ia64 - * - * Copyright (C) 2003 Ken Chen - * Copyright (C) 2003 Asit Mallick - * Copyright (C) 2005 Christoph Lameter - * - * Based on asm-i386/rwsem.h and other architecture implementation. - * - * The MSW of the count is the negated number of active writers and - * waiting lockers, and the LSW is the total number of active locks. - * - * The lock count is initialized to 0 (no active and no waiting lockers). - * - * When a writer subtracts WRITE_BIAS, it'll get 0xffffffff00000001 for - * the case of an uncontended lock. Readers increment by 1 and see a positive - * value when uncontended, negative if there are writers (and maybe) readers - * waiting (in which case it goes to sleep). - */ - -#ifndef _ASM_IA64_RWSEM_H -#define _ASM_IA64_RWSEM_H - -#ifndef _LINUX_RWSEM_H -#error "Please don't include directly, use instead." -#endif - -#include - -#define RWSEM_UNLOCKED_VALUE __IA64_UL_CONST(0x0000000000000000) -#define RWSEM_ACTIVE_BIAS (1L) -#define RWSEM_ACTIVE_MASK (0xffffffffL) -#define RWSEM_WAITING_BIAS (-0x100000000L) -#define RWSEM_ACTIVE_READ_BIAS RWSEM_ACTIVE_BIAS -#define RWSEM_ACTIVE_WRITE_BIAS (RWSEM_WAITING_BIAS + RWSEM_ACTIVE_BIAS) - -/* - * lock for reading - */ -static inline int -___down_read (struct rw_semaphore *sem) -{ - long result = ia64_fetchadd8_acq((unsigned long *)&sem->count.counter, 1); - - return (result < 0); -} - -static inline void -__down_read (struct rw_semaphore *sem) -{ - if (___down_read(sem)) - rwsem_down_read_failed(sem); -} - -static inline int -__down_read_killable (struct rw_semaphore *sem) -{ - if (___down_read(sem)) - if (IS_ERR(rwsem_down_read_failed_killable(sem))) - return -EINTR; - - return 0; -} - -/* - * lock for writing - */ -static inline long -___down_write (struct rw_semaphore *sem) -{ - long old, new; - - do { - old = atomic_long_read(&sem->count); - new = old + RWSEM_ACTIVE_WRITE_BIAS; - } while (atomic_long_cmpxchg_acquire(&sem->count, old, new) != old); - - return old; -} - -static inline void -__down_write (struct rw_semaphore *sem) -{ - if (___down_write(sem)) - rwsem_down_write_failed(sem); -} - -static inline int -__down_write_killable (struct rw_semaphore *sem) -{ - if (___down_write(sem)) { - if (IS_ERR(rwsem_down_write_failed_killable(sem))) - return -EINTR; - } - - return 0; -} - -/* - * unlock after reading - */ -static inline void -__up_read (struct rw_semaphore *sem) -{ - long result = ia64_fetchadd8_rel((unsigned long *)&sem->count.counter, -1); - - if (result < 0 && (--result & RWSEM_ACTIVE_MASK) == 0) - rwsem_wake(sem); -} - -/* - * unlock after writing - */ -static inline void -__up_write (struct rw_semaphore *sem) -{ - long old, new; - - do { - old = atomic_long_read(&sem->count); - new = old - RWSEM_ACTIVE_WRITE_BIAS; - } while (atomic_long_cmpxchg_release(&sem->count, old, new) != old); - - if (new < 0 && (new & RWSEM_ACTIVE_MASK) == 0) - rwsem_wake(sem); -} - -/* - * trylock for reading -- returns 1 if successful, 0 if contention - */ -static inline int -__down_read_trylock (struct rw_semaphore *sem) -{ - long tmp; - while ((tmp = atomic_long_read(&sem->count)) >= 0) { - if (tmp == atomic_long_cmpxchg_acquire(&sem->count, tmp, tmp+1)) { - return 1; - } - } - return 0; -} - -/* - * trylock for writing -- returns 1 if successful, 0 if contention - */ -static inline int -__down_write_trylock (struct rw_semaphore *sem) -{ - long tmp = atomic_long_cmpxchg_acquire(&sem->count, - RWSEM_UNLOCKED_VALUE, RWSEM_ACTIVE_WRITE_BIAS); - return tmp == RWSEM_UNLOCKED_VALUE; -} - -/* - * downgrade write lock to read lock - */ -static inline void -__downgrade_write (struct rw_semaphore *sem) -{ - long old, new; - - do { - old = atomic_long_read(&sem->count); - new = old - RWSEM_WAITING_BIAS; - } while (atomic_long_cmpxchg_release(&sem->count, old, new) != old); - - if (old < 0) - rwsem_downgrade_wake(sem); -} - -#endif /* _ASM_IA64_RWSEM_H */ diff --git a/arch/powerpc/include/asm/Kbuild b/arch/powerpc/include/asm/Kbuild index a0c132bedfae..36bda391e549 100644 --- a/arch/powerpc/include/asm/Kbuild +++ b/arch/powerpc/include/asm/Kbuild @@ -8,6 +8,5 @@ generic-y += irq_regs.h generic-y += local64.h generic-y += mcs_spinlock.h generic-y += preempt.h -generic-y += rwsem.h generic-y += vtime.h generic-y += msi.h diff --git a/arch/s390/include/asm/Kbuild b/arch/s390/include/asm/Kbuild index 12d77cb11fe5..d5fadefea33c 100644 --- a/arch/s390/include/asm/Kbuild +++ b/arch/s390/include/asm/Kbuild @@ -20,7 +20,6 @@ generic-y += local.h generic-y += local64.h generic-y += mcs_spinlock.h generic-y += mm-arch-hooks.h -generic-y += rwsem.h generic-y += trace_clock.h generic-y += unaligned.h generic-y += word-at-a-time.h diff --git a/arch/sh/include/asm/Kbuild b/arch/sh/include/asm/Kbuild index 7bf2cb680d32..73fff39a0122 100644 --- a/arch/sh/include/asm/Kbuild +++ b/arch/sh/include/asm/Kbuild @@ -17,7 +17,6 @@ generic-y += mm-arch-hooks.h generic-y += parport.h generic-y += percpu.h generic-y += preempt.h -generic-y += rwsem.h generic-y += serial.h generic-y += sizes.h generic-y += trace_clock.h diff --git a/arch/sparc/include/asm/Kbuild b/arch/sparc/include/asm/Kbuild index a22cfd5c0ee8..2ca3200d3616 100644 --- a/arch/sparc/include/asm/Kbuild +++ b/arch/sparc/include/asm/Kbuild @@ -18,7 +18,6 @@ generic-y += mm-arch-hooks.h generic-y += module.h generic-y += msi.h generic-y += preempt.h -generic-y += rwsem.h generic-y += serial.h generic-y += trace_clock.h generic-y += word-at-a-time.h diff --git a/arch/x86/include/asm/rwsem.h b/arch/x86/include/asm/rwsem.h deleted file mode 100644 index 4c25cf6caefa..000000000000 --- a/arch/x86/include/asm/rwsem.h +++ /dev/null @@ -1,237 +0,0 @@ -/* SPDX-License-Identifier: GPL-2.0 */ -/* rwsem.h: R/W semaphores implemented using XADD/CMPXCHG for i486+ - * - * Written by David Howells (dhowells@redhat.com). - * - * Derived from asm-x86/semaphore.h - * - * - * The MSW of the count is the negated number of active writers and waiting - * lockers, and the LSW is the total number of active locks - * - * The lock count is initialized to 0 (no active and no waiting lockers). - * - * When a writer subtracts WRITE_BIAS, it'll get 0xffff0001 for the case of an - * uncontended lock. This can be determined because XADD returns the old value. - * Readers increment by 1 and see a positive value when uncontended, negative - * if there are writers (and maybe) readers waiting (in which case it goes to - * sleep). - * - * The value of WAITING_BIAS supports up to 32766 waiting processes. This can - * be extended to 65534 by manually checking the whole MSW rather than relying - * on the S flag. - * - * The value of ACTIVE_BIAS supports up to 65535 active processes. - * - * This should be totally fair - if anything is waiting, a process that wants a - * lock will go to the back of the queue. When the currently active lock is - * released, if there's a writer at the front of the queue, then that and only - * that will be woken up; if there's a bunch of consecutive readers at the - * front, then they'll all be woken up, but no other readers will be. - */ - -#ifndef _ASM_X86_RWSEM_H -#define _ASM_X86_RWSEM_H - -#ifndef _LINUX_RWSEM_H -#error "please don't include asm/rwsem.h directly, use linux/rwsem.h instead" -#endif - -#ifdef __KERNEL__ -#include - -/* - * The bias values and the counter type limits the number of - * potential readers/writers to 32767 for 32 bits and 2147483647 - * for 64 bits. - */ - -#ifdef CONFIG_X86_64 -# define RWSEM_ACTIVE_MASK 0xffffffffL -#else -# define RWSEM_ACTIVE_MASK 0x0000ffffL -#endif - -#define RWSEM_UNLOCKED_VALUE 0x00000000L -#define RWSEM_ACTIVE_BIAS 0x00000001L -#define RWSEM_WAITING_BIAS (-RWSEM_ACTIVE_MASK-1) -#define RWSEM_ACTIVE_READ_BIAS RWSEM_ACTIVE_BIAS -#define RWSEM_ACTIVE_WRITE_BIAS (RWSEM_WAITING_BIAS + RWSEM_ACTIVE_BIAS) - -/* - * lock for reading - */ -#define ____down_read(sem, slow_path) \ -({ \ - struct rw_semaphore* ret; \ - asm volatile("# beginning down_read\n\t" \ - LOCK_PREFIX _ASM_INC "(%[sem])\n\t" \ - /* adds 0x00000001 */ \ - " jns 1f\n" \ - " call " slow_path "\n" \ - "1:\n\t" \ - "# ending down_read\n\t" \ - : "+m" (sem->count), "=a" (ret), \ - ASM_CALL_CONSTRAINT \ - : [sem] "a" (sem) \ - : "memory", "cc"); \ - ret; \ -}) - -static inline void __down_read(struct rw_semaphore *sem) -{ - ____down_read(sem, "call_rwsem_down_read_failed"); -} - -static inline int __down_read_killable(struct rw_semaphore *sem) -{ - if (IS_ERR(____down_read(sem, "call_rwsem_down_read_failed_killable"))) - return -EINTR; - return 0; -} - -/* - * trylock for reading -- returns 1 if successful, 0 if contention - */ -static inline bool __down_read_trylock(struct rw_semaphore *sem) -{ - long result, tmp; - asm volatile("# beginning __down_read_trylock\n\t" - " mov %[count],%[result]\n\t" - "1:\n\t" - " mov %[result],%[tmp]\n\t" - " add %[inc],%[tmp]\n\t" - " jle 2f\n\t" - LOCK_PREFIX " cmpxchg %[tmp],%[count]\n\t" - " jnz 1b\n\t" - "2:\n\t" - "# ending __down_read_trylock\n\t" - : [count] "+m" (sem->count), [result] "=&a" (result), - [tmp] "=&r" (tmp) - : [inc] "i" (RWSEM_ACTIVE_READ_BIAS) - : "memory", "cc"); - return result >= 0; -} - -/* - * lock for writing - */ -#define ____down_write(sem, slow_path) \ -({ \ - long tmp; \ - struct rw_semaphore* ret; \ - \ - asm volatile("# beginning down_write\n\t" \ - LOCK_PREFIX " xadd %[tmp],(%[sem])\n\t" \ - /* adds 0xffff0001, returns the old value */ \ - " test " __ASM_SEL(%w1,%k1) "," __ASM_SEL(%w1,%k1) "\n\t" \ - /* was the active mask 0 before? */\ - " jz 1f\n" \ - " call " slow_path "\n" \ - "1:\n" \ - "# ending down_write" \ - : "+m" (sem->count), [tmp] "=d" (tmp), \ - "=a" (ret), ASM_CALL_CONSTRAINT \ - : [sem] "a" (sem), "[tmp]" (RWSEM_ACTIVE_WRITE_BIAS) \ - : "memory", "cc"); \ - ret; \ -}) - -static inline void __down_write(struct rw_semaphore *sem) -{ - ____down_write(sem, "call_rwsem_down_write_failed"); -} - -static inline int __down_write_killable(struct rw_semaphore *sem) -{ - if (IS_ERR(____down_write(sem, "call_rwsem_down_write_failed_killable"))) - return -EINTR; - - return 0; -} - -/* - * trylock for writing -- returns 1 if successful, 0 if contention - */ -static inline bool __down_write_trylock(struct rw_semaphore *sem) -{ - bool result; - long tmp0, tmp1; - asm volatile("# beginning __down_write_trylock\n\t" - " mov %[count],%[tmp0]\n\t" - "1:\n\t" - " test " __ASM_SEL(%w1,%k1) "," __ASM_SEL(%w1,%k1) "\n\t" - /* was the active mask 0 before? */ - " jnz 2f\n\t" - " mov %[tmp0],%[tmp1]\n\t" - " add %[inc],%[tmp1]\n\t" - LOCK_PREFIX " cmpxchg %[tmp1],%[count]\n\t" - " jnz 1b\n\t" - "2:\n\t" - CC_SET(e) - "# ending __down_write_trylock\n\t" - : [count] "+m" (sem->count), [tmp0] "=&a" (tmp0), - [tmp1] "=&r" (tmp1), CC_OUT(e) (result) - : [inc] "er" (RWSEM_ACTIVE_WRITE_BIAS) - : "memory"); - return result; -} - -/* - * unlock after reading - */ -static inline void __up_read(struct rw_semaphore *sem) -{ - long tmp; - asm volatile("# beginning __up_read\n\t" - LOCK_PREFIX " xadd %[tmp],(%[sem])\n\t" - /* subtracts 1, returns the old value */ - " jns 1f\n\t" - " call call_rwsem_wake\n" /* expects old value in %edx */ - "1:\n" - "# ending __up_read\n" - : "+m" (sem->count), [tmp] "=d" (tmp) - : [sem] "a" (sem), "[tmp]" (-RWSEM_ACTIVE_READ_BIAS) - : "memory", "cc"); -} - -/* - * unlock after writing - */ -static inline void __up_write(struct rw_semaphore *sem) -{ - long tmp; - asm volatile("# beginning __up_write\n\t" - LOCK_PREFIX " xadd %[tmp],(%[sem])\n\t" - /* subtracts 0xffff0001, returns the old value */ - " jns 1f\n\t" - " call call_rwsem_wake\n" /* expects old value in %edx */ - "1:\n\t" - "# ending __up_write\n" - : "+m" (sem->count), [tmp] "=d" (tmp) - : [sem] "a" (sem), "[tmp]" (-RWSEM_ACTIVE_WRITE_BIAS) - : "memory", "cc"); -} - -/* - * downgrade write lock to read lock - */ -static inline void __downgrade_write(struct rw_semaphore *sem) -{ - asm volatile("# beginning __downgrade_write\n\t" - LOCK_PREFIX _ASM_ADD "%[inc],(%[sem])\n\t" - /* - * transitions 0xZZZZ0001 -> 0xYYYY0001 (i386) - * 0xZZZZZZZZ00000001 -> 0xYYYYYYYY00000001 (x86_64) - */ - " jns 1f\n\t" - " call call_rwsem_downgrade_wake\n" - "1:\n\t" - "# ending __downgrade_write\n" - : "+m" (sem->count) - : [sem] "a" (sem), [inc] "er" (-RWSEM_WAITING_BIAS) - : "memory", "cc"); -} - -#endif /* __KERNEL__ */ -#endif /* _ASM_X86_RWSEM_H */ diff --git a/arch/x86/lib/Makefile b/arch/x86/lib/Makefile index 140e61843a07..986652064b15 100644 --- a/arch/x86/lib/Makefile +++ b/arch/x86/lib/Makefile @@ -23,7 +23,6 @@ obj-$(CONFIG_SMP) += msr-smp.o cache-smp.o lib-y := delay.o misc.o cmdline.o cpu.o lib-y += usercopy_$(BITS).o usercopy.o getuser.o putuser.o lib-y += memcpy_$(BITS).o -lib-$(CONFIG_RWSEM_XCHGADD_ALGORITHM) += rwsem.o lib-$(CONFIG_INSTRUCTION_DECODER) += insn.o inat.o insn-eval.o lib-$(CONFIG_RANDOMIZE_BASE) += kaslr.o lib-$(CONFIG_FUNCTION_ERROR_INJECTION) += error-inject.o diff --git a/arch/x86/lib/rwsem.S b/arch/x86/lib/rwsem.S deleted file mode 100644 index dc2ab6ea6768..000000000000 --- a/arch/x86/lib/rwsem.S +++ /dev/null @@ -1,156 +0,0 @@ -/* - * x86 semaphore implementation. - * - * (C) Copyright 1999 Linus Torvalds - * - * Portions Copyright 1999 Red Hat, Inc. - * - * 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. - * - * rw semaphores implemented November 1999 by Benjamin LaHaise - */ - -#include -#include -#include - -#define __ASM_HALF_REG(reg) __ASM_SEL(reg, e##reg) -#define __ASM_HALF_SIZE(inst) __ASM_SEL(inst##w, inst##l) - -#ifdef CONFIG_X86_32 - -/* - * The semaphore operations have a special calling sequence that - * allow us to do a simpler in-line version of them. These routines - * need to convert that sequence back into the C sequence when - * there is contention on the semaphore. - * - * %eax contains the semaphore pointer on entry. Save the C-clobbered - * registers (%eax, %edx and %ecx) except %eax which is either a return - * value or just gets clobbered. Same is true for %edx so make sure GCC - * reloads it after the slow path, by making it hold a temporary, for - * example see ____down_write(). - */ - -#define save_common_regs \ - pushl %ecx - -#define restore_common_regs \ - popl %ecx - - /* Avoid uglifying the argument copying x86-64 needs to do. */ - .macro movq src, dst - .endm - -#else - -/* - * x86-64 rwsem wrappers - * - * This interfaces the inline asm code to the slow-path - * C routines. We need to save the call-clobbered regs - * that the asm does not mark as clobbered, and move the - * argument from %rax to %rdi. - * - * NOTE! We don't need to save %rax, because the functions - * will always return the semaphore pointer in %rax (which - * is also the input argument to these helpers) - * - * The following can clobber %rdx because the asm clobbers it: - * call_rwsem_down_write_failed - * call_rwsem_wake - * but %rdi, %rsi, %rcx, %r8-r11 always need saving. - */ - -#define save_common_regs \ - pushq %rdi; \ - pushq %rsi; \ - pushq %rcx; \ - pushq %r8; \ - pushq %r9; \ - pushq %r10; \ - pushq %r11 - -#define restore_common_regs \ - popq %r11; \ - popq %r10; \ - popq %r9; \ - popq %r8; \ - popq %rcx; \ - popq %rsi; \ - popq %rdi - -#endif - -/* Fix up special calling conventions */ -ENTRY(call_rwsem_down_read_failed) - FRAME_BEGIN - save_common_regs - __ASM_SIZE(push,) %__ASM_REG(dx) - movq %rax,%rdi - call rwsem_down_read_failed - __ASM_SIZE(pop,) %__ASM_REG(dx) - restore_common_regs - FRAME_END - ret -ENDPROC(call_rwsem_down_read_failed) - -ENTRY(call_rwsem_down_read_failed_killable) - FRAME_BEGIN - save_common_regs - __ASM_SIZE(push,) %__ASM_REG(dx) - movq %rax,%rdi - call rwsem_down_read_failed_killable - __ASM_SIZE(pop,) %__ASM_REG(dx) - restore_common_regs - FRAME_END - ret -ENDPROC(call_rwsem_down_read_failed_killable) - -ENTRY(call_rwsem_down_write_failed) - FRAME_BEGIN - save_common_regs - movq %rax,%rdi - call rwsem_down_write_failed - restore_common_regs - FRAME_END - ret -ENDPROC(call_rwsem_down_write_failed) - -ENTRY(call_rwsem_down_write_failed_killable) - FRAME_BEGIN - save_common_regs - movq %rax,%rdi - call rwsem_down_write_failed_killable - restore_common_regs - FRAME_END - ret -ENDPROC(call_rwsem_down_write_failed_killable) - -ENTRY(call_rwsem_wake) - FRAME_BEGIN - /* do nothing if still outstanding active readers */ - __ASM_HALF_SIZE(dec) %__ASM_HALF_REG(dx) - jnz 1f - save_common_regs - movq %rax,%rdi - call rwsem_wake - restore_common_regs -1: FRAME_END - ret -ENDPROC(call_rwsem_wake) - -ENTRY(call_rwsem_downgrade_wake) - FRAME_BEGIN - save_common_regs - __ASM_SIZE(push,) %__ASM_REG(dx) - movq %rax,%rdi - call rwsem_downgrade_wake - __ASM_SIZE(pop,) %__ASM_REG(dx) - restore_common_regs - FRAME_END - ret -ENDPROC(call_rwsem_downgrade_wake) diff --git a/arch/x86/um/Makefile b/arch/x86/um/Makefile index 2d686ae54681..33c51c064c77 100644 --- a/arch/x86/um/Makefile +++ b/arch/x86/um/Makefile @@ -21,14 +21,12 @@ obj-y += checksum_32.o syscalls_32.o obj-$(CONFIG_ELF_CORE) += elfcore.o subarch-y = ../lib/string_32.o ../lib/atomic64_32.o ../lib/atomic64_cx8_32.o -subarch-$(CONFIG_RWSEM_XCHGADD_ALGORITHM) += ../lib/rwsem.o else obj-y += syscalls_64.o vdso/ -subarch-y = ../lib/csum-partial_64.o ../lib/memcpy_64.o ../entry/thunk_64.o \ - ../lib/rwsem.o +subarch-y = ../lib/csum-partial_64.o ../lib/memcpy_64.o ../entry/thunk_64.o endif diff --git a/arch/xtensa/include/asm/Kbuild b/arch/xtensa/include/asm/Kbuild index 3843198e03d4..4148090cafb0 100644 --- a/arch/xtensa/include/asm/Kbuild +++ b/arch/xtensa/include/asm/Kbuild @@ -25,7 +25,6 @@ generic-y += percpu.h generic-y += preempt.h generic-y += qrwlock.h generic-y += qspinlock.h -generic-y += rwsem.h generic-y += sections.h generic-y += socket.h generic-y += topology.h diff --git a/include/asm-generic/rwsem.h b/include/asm-generic/rwsem.h deleted file mode 100644 index 93e67a055a4d..000000000000 --- a/include/asm-generic/rwsem.h +++ /dev/null @@ -1,140 +0,0 @@ -/* SPDX-License-Identifier: GPL-2.0 */ -#ifndef _ASM_GENERIC_RWSEM_H -#define _ASM_GENERIC_RWSEM_H - -#ifndef _LINUX_RWSEM_H -#error "Please don't include directly, use instead." -#endif - -#ifdef __KERNEL__ - -/* - * R/W semaphores originally for PPC using the stuff in lib/rwsem.c. - * Adapted largely from include/asm-i386/rwsem.h - * by Paul Mackerras . - */ - -/* - * the semaphore definition - */ -#ifdef CONFIG_64BIT -# define RWSEM_ACTIVE_MASK 0xffffffffL -#else -# define RWSEM_ACTIVE_MASK 0x0000ffffL -#endif - -#define RWSEM_UNLOCKED_VALUE 0x00000000L -#define RWSEM_ACTIVE_BIAS 0x00000001L -#define RWSEM_WAITING_BIAS (-RWSEM_ACTIVE_MASK-1) -#define RWSEM_ACTIVE_READ_BIAS RWSEM_ACTIVE_BIAS -#define RWSEM_ACTIVE_WRITE_BIAS (RWSEM_WAITING_BIAS + RWSEM_ACTIVE_BIAS) - -/* - * lock for reading - */ -static inline void __down_read(struct rw_semaphore *sem) -{ - if (unlikely(atomic_long_inc_return_acquire(&sem->count) <= 0)) - rwsem_down_read_failed(sem); -} - -static inline int __down_read_killable(struct rw_semaphore *sem) -{ - if (unlikely(atomic_long_inc_return_acquire(&sem->count) <= 0)) { - if (IS_ERR(rwsem_down_read_failed_killable(sem))) - return -EINTR; - } - - return 0; -} - -static inline int __down_read_trylock(struct rw_semaphore *sem) -{ - long tmp; - - while ((tmp = atomic_long_read(&sem->count)) >= 0) { - if (tmp == atomic_long_cmpxchg_acquire(&sem->count, tmp, - tmp + RWSEM_ACTIVE_READ_BIAS)) { - return 1; - } - } - return 0; -} - -/* - * lock for writing - */ -static inline void __down_write(struct rw_semaphore *sem) -{ - long tmp; - - tmp = atomic_long_add_return_acquire(RWSEM_ACTIVE_WRITE_BIAS, - &sem->count); - if (unlikely(tmp != RWSEM_ACTIVE_WRITE_BIAS)) - rwsem_down_write_failed(sem); -} - -static inline int __down_write_killable(struct rw_semaphore *sem) -{ - long tmp; - - tmp = atomic_long_add_return_acquire(RWSEM_ACTIVE_WRITE_BIAS, - &sem->count); - if (unlikely(tmp != RWSEM_ACTIVE_WRITE_BIAS)) - if (IS_ERR(rwsem_down_write_failed_killable(sem))) - return -EINTR; - return 0; -} - -static inline int __down_write_trylock(struct rw_semaphore *sem) -{ - long tmp; - - tmp = atomic_long_cmpxchg_acquire(&sem->count, RWSEM_UNLOCKED_VALUE, - RWSEM_ACTIVE_WRITE_BIAS); - return tmp == RWSEM_UNLOCKED_VALUE; -} - -/* - * unlock after reading - */ -static inline void __up_read(struct rw_semaphore *sem) -{ - long tmp; - - tmp = atomic_long_dec_return_release(&sem->count); - if (unlikely(tmp < -1 && (tmp & RWSEM_ACTIVE_MASK) == 0)) - rwsem_wake(sem); -} - -/* - * unlock after writing - */ -static inline void __up_write(struct rw_semaphore *sem) -{ - if (unlikely(atomic_long_sub_return_release(RWSEM_ACTIVE_WRITE_BIAS, - &sem->count) < 0)) - rwsem_wake(sem); -} - -/* - * downgrade write lock to read lock - */ -static inline void __downgrade_write(struct rw_semaphore *sem) -{ - long tmp; - - /* - * When downgrading from exclusive to shared ownership, - * anything inside the write-locked region cannot leak - * into the read side. In contrast, anything in the - * read-locked region is ok to be re-ordered into the - * write side. As such, rely on RELEASE semantics. - */ - tmp = atomic_long_add_return_release(-RWSEM_WAITING_BIAS, &sem->count); - if (tmp < 0) - rwsem_downgrade_wake(sem); -} - -#endif /* __KERNEL__ */ -#endif /* _ASM_GENERIC_RWSEM_H */ diff --git a/include/linux/rwsem.h b/include/linux/rwsem.h index 67dbb57508b1..6e56006b2cb6 100644 --- a/include/linux/rwsem.h +++ b/include/linux/rwsem.h @@ -57,15 +57,13 @@ extern struct rw_semaphore *rwsem_down_write_failed_killable(struct rw_semaphore extern struct rw_semaphore *rwsem_wake(struct rw_semaphore *); extern struct rw_semaphore *rwsem_downgrade_wake(struct rw_semaphore *sem); -/* Include the arch specific part */ -#include - /* In all implementations count != 0 means locked */ static inline int rwsem_is_locked(struct rw_semaphore *sem) { return atomic_long_read(&sem->count) != 0; } +#define RWSEM_UNLOCKED_VALUE 0L #define __RWSEM_INIT_COUNT(name) .count = ATOMIC_LONG_INIT(RWSEM_UNLOCKED_VALUE) #endif diff --git a/kernel/locking/percpu-rwsem.c b/kernel/locking/percpu-rwsem.c index 883cf1b92d90..f17dad99eec8 100644 --- a/kernel/locking/percpu-rwsem.c +++ b/kernel/locking/percpu-rwsem.c @@ -7,6 +7,8 @@ #include #include +#include "rwsem.h" + int __percpu_init_rwsem(struct percpu_rw_semaphore *sem, const char *name, struct lock_class_key *rwsem_key) { diff --git a/kernel/locking/rwsem.h b/kernel/locking/rwsem.h index bad2bca0268b..067e265fa5c1 100644 --- a/kernel/locking/rwsem.h +++ b/kernel/locking/rwsem.h @@ -32,6 +32,26 @@ # define DEBUG_RWSEMS_WARN_ON(c) #endif +/* + * R/W semaphores originally for PPC using the stuff in lib/rwsem.c. + * Adapted largely from include/asm-i386/rwsem.h + * by Paul Mackerras . + */ + +/* + * the semaphore definition + */ +#ifdef CONFIG_64BIT +# define RWSEM_ACTIVE_MASK 0xffffffffL +#else +# define RWSEM_ACTIVE_MASK 0x0000ffffL +#endif + +#define RWSEM_ACTIVE_BIAS 0x00000001L +#define RWSEM_WAITING_BIAS (-RWSEM_ACTIVE_MASK-1) +#define RWSEM_ACTIVE_READ_BIAS RWSEM_ACTIVE_BIAS +#define RWSEM_ACTIVE_WRITE_BIAS (RWSEM_WAITING_BIAS + RWSEM_ACTIVE_BIAS) + #ifdef CONFIG_RWSEM_SPIN_ON_OWNER /* * All writes to owner are protected by WRITE_ONCE() to make sure that @@ -132,3 +152,113 @@ static inline void rwsem_clear_reader_owned(struct rw_semaphore *sem) { } #endif + +#ifdef CONFIG_RWSEM_XCHGADD_ALGORITHM +/* + * lock for reading + */ +static inline void __down_read(struct rw_semaphore *sem) +{ + if (unlikely(atomic_long_inc_return_acquire(&sem->count) <= 0)) + rwsem_down_read_failed(sem); +} + +static inline int __down_read_killable(struct rw_semaphore *sem) +{ + if (unlikely(atomic_long_inc_return_acquire(&sem->count) <= 0)) { + if (IS_ERR(rwsem_down_read_failed_killable(sem))) + return -EINTR; + } + + return 0; +} + +static inline int __down_read_trylock(struct rw_semaphore *sem) +{ + long tmp; + + while ((tmp = atomic_long_read(&sem->count)) >= 0) { + if (tmp == atomic_long_cmpxchg_acquire(&sem->count, tmp, + tmp + RWSEM_ACTIVE_READ_BIAS)) { + return 1; + } + } + return 0; +} + +/* + * lock for writing + */ +static inline void __down_write(struct rw_semaphore *sem) +{ + long tmp; + + tmp = atomic_long_add_return_acquire(RWSEM_ACTIVE_WRITE_BIAS, + &sem->count); + if (unlikely(tmp != RWSEM_ACTIVE_WRITE_BIAS)) + rwsem_down_write_failed(sem); +} + +static inline int __down_write_killable(struct rw_semaphore *sem) +{ + long tmp; + + tmp = atomic_long_add_return_acquire(RWSEM_ACTIVE_WRITE_BIAS, + &sem->count); + if (unlikely(tmp != RWSEM_ACTIVE_WRITE_BIAS)) + if (IS_ERR(rwsem_down_write_failed_killable(sem))) + return -EINTR; + return 0; +} + +static inline int __down_write_trylock(struct rw_semaphore *sem) +{ + long tmp; + + tmp = atomic_long_cmpxchg_acquire(&sem->count, RWSEM_UNLOCKED_VALUE, + RWSEM_ACTIVE_WRITE_BIAS); + return tmp == RWSEM_UNLOCKED_VALUE; +} + +/* + * unlock after reading + */ +static inline void __up_read(struct rw_semaphore *sem) +{ + long tmp; + + tmp = atomic_long_dec_return_release(&sem->count); + if (unlikely(tmp < -1 && (tmp & RWSEM_ACTIVE_MASK) == 0)) + rwsem_wake(sem); +} + +/* + * unlock after writing + */ +static inline void __up_write(struct rw_semaphore *sem) +{ + if (unlikely(atomic_long_sub_return_release(RWSEM_ACTIVE_WRITE_BIAS, + &sem->count) < 0)) + rwsem_wake(sem); +} + +/* + * downgrade write lock to read lock + */ +static inline void __downgrade_write(struct rw_semaphore *sem) +{ + long tmp; + + /* + * When downgrading from exclusive to shared ownership, + * anything inside the write-locked region cannot leak + * into the read side. In contrast, anything in the + * read-locked region is ok to be re-ordered into the + * write side. As such, rely on RELEASE semantics. + */ + tmp = atomic_long_add_return_release(-RWSEM_WAITING_BIAS, &sem->count); + if (tmp < 0) + rwsem_downgrade_wake(sem); +} + +#endif /* CONFIG_RWSEM_XCHGADD_ALGORITHM */