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-rw-r--r--MAINTAINERS1
-rw-r--r--arch/alpha/include/asm/rwsem.h211
-rw-r--r--arch/arm/include/asm/Kbuild1
-rw-r--r--arch/arm64/include/asm/Kbuild1
-rw-r--r--arch/hexagon/include/asm/Kbuild1
-rw-r--r--arch/ia64/include/asm/rwsem.h172
-rw-r--r--arch/powerpc/include/asm/Kbuild1
-rw-r--r--arch/s390/include/asm/Kbuild1
-rw-r--r--arch/sh/include/asm/Kbuild1
-rw-r--r--arch/sparc/include/asm/Kbuild1
-rw-r--r--arch/x86/include/asm/rwsem.h237
-rw-r--r--arch/x86/lib/Makefile1
-rw-r--r--arch/x86/lib/rwsem.S156
-rw-r--r--arch/x86/um/Makefile4
-rw-r--r--arch/xtensa/include/asm/Kbuild1
-rw-r--r--include/asm-generic/rwsem.h140
-rw-r--r--include/linux/rwsem.h4
-rw-r--r--kernel/locking/percpu-rwsem.c2
-rw-r--r--kernel/locking/rwsem.h130
19 files changed, 134 insertions, 932 deletions
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 <ink@jurassic.park.msu.ru>, 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 <linux/compiler.h>
-
-#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 <kenneth.w.chen@intel.com>
- * Copyright (C) 2003 Asit Mallick <asit.k.mallick@intel.com>
- * Copyright (C) 2005 Christoph Lameter <cl@linux.com>
- *
- * 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 <asm/rwsem.h> directly, use <linux/rwsem.h> instead."
-#endif
-
-#include <asm/intrinsics.h>
-
-#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 <asm/asm.h>
-
-/*
- * 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 <bcrl@kvack.org>
- */
-
-#include <linux/linkage.h>
-#include <asm/alternative-asm.h>
-#include <asm/frame.h>
-
-#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 <asm/rwsem.h> directly, use <linux/rwsem.h> 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 <paulus@samba.org>.
- */
-
-/*
- * 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 <asm/rwsem.h>
-
/* 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 <linux/sched.h>
#include <linux/errno.h>
+#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 <paulus@samba.org>.
+ */
+
+/*
+ * 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 */
Copyright © 1996 – 2023 Jason A. Donenfeld. All Rights Reverse Engineered.