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author | Linus Torvalds <torvalds@linux-foundation.org> | 2014-01-20 10:23:08 -0800 |
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committer | Linus Torvalds <torvalds@linux-foundation.org> | 2014-01-20 10:23:08 -0800 |
commit | 6ffbe7d1fabddc768724656f159759cae7818cd9 (patch) | |
tree | ece184db0c35bcd9606968303984b430c24b847f /arch | |
parent | 897aea303fec0c24b2a21b8e29f45dc73a234555 (diff) | |
parent | 63b1a81699c2a45c9f737419b1ec1da0ecf92812 (diff) | |
download | linux-6ffbe7d1fabddc768724656f159759cae7818cd9.tar.bz2 |
Merge branch 'core-locking-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip
Pull core locking changes from Ingo Molnar:
- futex performance increases: larger hashes, smarter wakeups
- mutex debugging improvements
- lots of SMP ordering documentation updates
- introduce the smp_load_acquire(), smp_store_release() primitives.
(There are WIP patches that make use of them - not yet merged)
- lockdep micro-optimizations
- lockdep improvement: better cover IRQ contexts
- liblockdep at last. We'll continue to monitor how useful this is
* 'core-locking-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip: (34 commits)
futexes: Fix futex_hashsize initialization
arch: Re-sort some Kbuild files to hopefully help avoid some conflicts
futexes: Avoid taking the hb->lock if there's nothing to wake up
futexes: Document multiprocessor ordering guarantees
futexes: Increase hash table size for better performance
futexes: Clean up various details
arch: Introduce smp_load_acquire(), smp_store_release()
arch: Clean up asm/barrier.h implementations using asm-generic/barrier.h
arch: Move smp_mb__{before,after}_atomic_{inc,dec}.h into asm/atomic.h
locking/doc: Rename LOCK/UNLOCK to ACQUIRE/RELEASE
mutexes: Give more informative mutex warning in the !lock->owner case
powerpc: Full barrier for smp_mb__after_unlock_lock()
rcu: Apply smp_mb__after_unlock_lock() to preserve grace periods
Documentation/memory-barriers.txt: Downgrade UNLOCK+BLOCK
locking: Add an smp_mb__after_unlock_lock() for UNLOCK+BLOCK barrier
Documentation/memory-barriers.txt: Document ACCESS_ONCE()
Documentation/memory-barriers.txt: Prohibit speculative writes
Documentation/memory-barriers.txt: Add long atomic examples to memory-barriers.txt
Documentation/memory-barriers.txt: Add needed ACCESS_ONCE() calls to memory-barriers.txt
Revert "smp/cpumask: Make CONFIG_CPUMASK_OFFSTACK=y usable without debug dependency"
...
Diffstat (limited to 'arch')
37 files changed, 251 insertions, 413 deletions
diff --git a/arch/alpha/include/asm/barrier.h b/arch/alpha/include/asm/barrier.h index ce8860a0b32d..3832bdb794fe 100644 --- a/arch/alpha/include/asm/barrier.h +++ b/arch/alpha/include/asm/barrier.h @@ -3,33 +3,18 @@ #include <asm/compiler.h> -#define mb() \ -__asm__ __volatile__("mb": : :"memory") +#define mb() __asm__ __volatile__("mb": : :"memory") +#define rmb() __asm__ __volatile__("mb": : :"memory") +#define wmb() __asm__ __volatile__("wmb": : :"memory") -#define rmb() \ -__asm__ __volatile__("mb": : :"memory") - -#define wmb() \ -__asm__ __volatile__("wmb": : :"memory") - -#define read_barrier_depends() \ -__asm__ __volatile__("mb": : :"memory") +#define read_barrier_depends() __asm__ __volatile__("mb": : :"memory") #ifdef CONFIG_SMP #define __ASM_SMP_MB "\tmb\n" -#define smp_mb() mb() -#define smp_rmb() rmb() -#define smp_wmb() wmb() -#define smp_read_barrier_depends() read_barrier_depends() #else #define __ASM_SMP_MB -#define smp_mb() barrier() -#define smp_rmb() barrier() -#define smp_wmb() barrier() -#define smp_read_barrier_depends() do { } while (0) #endif -#define set_mb(var, value) \ -do { var = value; mb(); } while (0) +#include <asm-generic/barrier.h> #endif /* __BARRIER_H */ diff --git a/arch/arc/include/asm/Kbuild b/arch/arc/include/asm/Kbuild index 5943f7f9d325..9ae21c198007 100644 --- a/arch/arc/include/asm/Kbuild +++ b/arch/arc/include/asm/Kbuild @@ -1,4 +1,5 @@ generic-y += auxvec.h +generic-y += barrier.h generic-y += bugs.h generic-y += bitsperlong.h generic-y += clkdev.h diff --git a/arch/arc/include/asm/atomic.h b/arch/arc/include/asm/atomic.h index 83f03ca6caf6..03e494f695d1 100644 --- a/arch/arc/include/asm/atomic.h +++ b/arch/arc/include/asm/atomic.h @@ -190,6 +190,11 @@ static inline void atomic_clear_mask(unsigned long mask, unsigned long *addr) #endif /* !CONFIG_ARC_HAS_LLSC */ +#define smp_mb__before_atomic_dec() barrier() +#define smp_mb__after_atomic_dec() barrier() +#define smp_mb__before_atomic_inc() barrier() +#define smp_mb__after_atomic_inc() barrier() + /** * __atomic_add_unless - add unless the number is a given value * @v: pointer of type atomic_t diff --git a/arch/arc/include/asm/barrier.h b/arch/arc/include/asm/barrier.h index f6cb7c4ffb35..c32245c3d1e9 100644 --- a/arch/arc/include/asm/barrier.h +++ b/arch/arc/include/asm/barrier.h @@ -30,11 +30,6 @@ #define smp_wmb() barrier() #endif -#define smp_mb__before_atomic_dec() barrier() -#define smp_mb__after_atomic_dec() barrier() -#define smp_mb__before_atomic_inc() barrier() -#define smp_mb__after_atomic_inc() barrier() - #define smp_read_barrier_depends() do { } while (0) #endif diff --git a/arch/arm/include/asm/barrier.h b/arch/arm/include/asm/barrier.h index 60f15e274e6d..2f59f7443396 100644 --- a/arch/arm/include/asm/barrier.h +++ b/arch/arm/include/asm/barrier.h @@ -59,6 +59,21 @@ #define smp_wmb() dmb(ishst) #endif +#define smp_store_release(p, v) \ +do { \ + compiletime_assert_atomic_type(*p); \ + smp_mb(); \ + ACCESS_ONCE(*p) = (v); \ +} while (0) + +#define smp_load_acquire(p) \ +({ \ + typeof(*p) ___p1 = ACCESS_ONCE(*p); \ + compiletime_assert_atomic_type(*p); \ + smp_mb(); \ + ___p1; \ +}) + #define read_barrier_depends() do { } while(0) #define smp_read_barrier_depends() do { } while(0) diff --git a/arch/arm64/include/asm/barrier.h b/arch/arm64/include/asm/barrier.h index d4a63338a53c..78e20ba8806b 100644 --- a/arch/arm64/include/asm/barrier.h +++ b/arch/arm64/include/asm/barrier.h @@ -35,10 +35,60 @@ #define smp_mb() barrier() #define smp_rmb() barrier() #define smp_wmb() barrier() + +#define smp_store_release(p, v) \ +do { \ + compiletime_assert_atomic_type(*p); \ + smp_mb(); \ + ACCESS_ONCE(*p) = (v); \ +} while (0) + +#define smp_load_acquire(p) \ +({ \ + typeof(*p) ___p1 = ACCESS_ONCE(*p); \ + compiletime_assert_atomic_type(*p); \ + smp_mb(); \ + ___p1; \ +}) + #else + #define smp_mb() asm volatile("dmb ish" : : : "memory") #define smp_rmb() asm volatile("dmb ishld" : : : "memory") #define smp_wmb() asm volatile("dmb ishst" : : : "memory") + +#define smp_store_release(p, v) \ +do { \ + compiletime_assert_atomic_type(*p); \ + switch (sizeof(*p)) { \ + case 4: \ + asm volatile ("stlr %w1, %0" \ + : "=Q" (*p) : "r" (v) : "memory"); \ + break; \ + case 8: \ + asm volatile ("stlr %1, %0" \ + : "=Q" (*p) : "r" (v) : "memory"); \ + break; \ + } \ +} while (0) + +#define smp_load_acquire(p) \ +({ \ + typeof(*p) ___p1; \ + compiletime_assert_atomic_type(*p); \ + switch (sizeof(*p)) { \ + case 4: \ + asm volatile ("ldar %w0, %1" \ + : "=r" (___p1) : "Q" (*p) : "memory"); \ + break; \ + case 8: \ + asm volatile ("ldar %0, %1" \ + : "=r" (___p1) : "Q" (*p) : "memory"); \ + break; \ + } \ + ___p1; \ +}) + #endif #define read_barrier_depends() do { } while(0) diff --git a/arch/avr32/include/asm/barrier.h b/arch/avr32/include/asm/barrier.h index 0961275373db..715100790fd0 100644 --- a/arch/avr32/include/asm/barrier.h +++ b/arch/avr32/include/asm/barrier.h @@ -8,22 +8,15 @@ #ifndef __ASM_AVR32_BARRIER_H #define __ASM_AVR32_BARRIER_H -#define nop() asm volatile("nop") - -#define mb() asm volatile("" : : : "memory") -#define rmb() mb() -#define wmb() asm volatile("sync 0" : : : "memory") -#define read_barrier_depends() do { } while(0) -#define set_mb(var, value) do { var = value; mb(); } while(0) +/* + * Weirdest thing ever.. no full barrier, but it has a write barrier! + */ +#define wmb() asm volatile("sync 0" : : : "memory") #ifdef CONFIG_SMP # error "The AVR32 port does not support SMP" -#else -# define smp_mb() barrier() -# define smp_rmb() barrier() -# define smp_wmb() barrier() -# define smp_read_barrier_depends() do { } while(0) #endif +#include <asm-generic/barrier.h> #endif /* __ASM_AVR32_BARRIER_H */ diff --git a/arch/blackfin/include/asm/barrier.h b/arch/blackfin/include/asm/barrier.h index ebb189507dd7..19283a16ac08 100644 --- a/arch/blackfin/include/asm/barrier.h +++ b/arch/blackfin/include/asm/barrier.h @@ -23,26 +23,10 @@ # define rmb() do { barrier(); smp_check_barrier(); } while (0) # define wmb() do { barrier(); smp_mark_barrier(); } while (0) # define read_barrier_depends() do { barrier(); smp_check_barrier(); } while (0) -#else -# define mb() barrier() -# define rmb() barrier() -# define wmb() barrier() -# define read_barrier_depends() do { } while (0) #endif -#else /* !CONFIG_SMP */ - -#define mb() barrier() -#define rmb() barrier() -#define wmb() barrier() -#define read_barrier_depends() do { } while (0) - #endif /* !CONFIG_SMP */ -#define smp_mb() mb() -#define smp_rmb() rmb() -#define smp_wmb() wmb() -#define set_mb(var, value) do { var = value; mb(); } while (0) -#define smp_read_barrier_depends() read_barrier_depends() +#include <asm-generic/barrier.h> #endif /* _BLACKFIN_BARRIER_H */ diff --git a/arch/cris/include/asm/Kbuild b/arch/cris/include/asm/Kbuild index b06caf649a95..199b1a9dab89 100644 --- a/arch/cris/include/asm/Kbuild +++ b/arch/cris/include/asm/Kbuild @@ -3,6 +3,7 @@ header-y += arch-v10/ header-y += arch-v32/ +generic-y += barrier.h generic-y += clkdev.h generic-y += exec.h generic-y += kvm_para.h diff --git a/arch/cris/include/asm/barrier.h b/arch/cris/include/asm/barrier.h deleted file mode 100644 index 198ad7fa6b25..000000000000 --- a/arch/cris/include/asm/barrier.h +++ /dev/null @@ -1,25 +0,0 @@ -#ifndef __ASM_CRIS_BARRIER_H -#define __ASM_CRIS_BARRIER_H - -#define nop() __asm__ __volatile__ ("nop"); - -#define barrier() __asm__ __volatile__("": : :"memory") -#define mb() barrier() -#define rmb() mb() -#define wmb() mb() -#define read_barrier_depends() do { } while(0) -#define set_mb(var, value) do { var = value; mb(); } while (0) - -#ifdef CONFIG_SMP -#define smp_mb() mb() -#define smp_rmb() rmb() -#define smp_wmb() wmb() -#define smp_read_barrier_depends() read_barrier_depends() -#else -#define smp_mb() barrier() -#define smp_rmb() barrier() -#define smp_wmb() barrier() -#define smp_read_barrier_depends() do { } while(0) -#endif - -#endif /* __ASM_CRIS_BARRIER_H */ diff --git a/arch/frv/include/asm/barrier.h b/arch/frv/include/asm/barrier.h index 06776ad9f5e9..abbef470154c 100644 --- a/arch/frv/include/asm/barrier.h +++ b/arch/frv/include/asm/barrier.h @@ -17,13 +17,7 @@ #define mb() asm volatile ("membar" : : :"memory") #define rmb() asm volatile ("membar" : : :"memory") #define wmb() asm volatile ("membar" : : :"memory") -#define read_barrier_depends() do { } while (0) -#define smp_mb() barrier() -#define smp_rmb() barrier() -#define smp_wmb() barrier() -#define smp_read_barrier_depends() do {} while(0) -#define set_mb(var, value) \ - do { var = (value); barrier(); } while (0) +#include <asm-generic/barrier.h> #endif /* _ASM_BARRIER_H */ diff --git a/arch/hexagon/include/asm/Kbuild b/arch/hexagon/include/asm/Kbuild index 67c3450309b7..ada843c701ef 100644 --- a/arch/hexagon/include/asm/Kbuild +++ b/arch/hexagon/include/asm/Kbuild @@ -2,6 +2,7 @@ header-y += ucontext.h generic-y += auxvec.h +generic-y += barrier.h generic-y += bug.h generic-y += bugs.h generic-y += clkdev.h diff --git a/arch/hexagon/include/asm/atomic.h b/arch/hexagon/include/asm/atomic.h index 8a64ff2337f6..7aae4cb2a29a 100644 --- a/arch/hexagon/include/asm/atomic.h +++ b/arch/hexagon/include/asm/atomic.h @@ -160,8 +160,12 @@ static inline int __atomic_add_unless(atomic_t *v, int a, int u) #define atomic_sub_and_test(i, v) (atomic_sub_return(i, (v)) == 0) #define atomic_add_negative(i, v) (atomic_add_return(i, (v)) < 0) - #define atomic_inc_return(v) (atomic_add_return(1, v)) #define atomic_dec_return(v) (atomic_sub_return(1, v)) +#define smp_mb__before_atomic_dec() barrier() +#define smp_mb__after_atomic_dec() barrier() +#define smp_mb__before_atomic_inc() barrier() +#define smp_mb__after_atomic_inc() barrier() + #endif diff --git a/arch/hexagon/include/asm/barrier.h b/arch/hexagon/include/asm/barrier.h index 1041a8e70ce8..4e863daea25b 100644 --- a/arch/hexagon/include/asm/barrier.h +++ b/arch/hexagon/include/asm/barrier.h @@ -29,10 +29,6 @@ #define smp_read_barrier_depends() barrier() #define smp_wmb() barrier() #define smp_mb() barrier() -#define smp_mb__before_atomic_dec() barrier() -#define smp_mb__after_atomic_dec() barrier() -#define smp_mb__before_atomic_inc() barrier() -#define smp_mb__after_atomic_inc() barrier() /* Set a value and use a memory barrier. Used by the scheduler somewhere. */ #define set_mb(var, value) \ diff --git a/arch/ia64/include/asm/barrier.h b/arch/ia64/include/asm/barrier.h index 60576e06b6fb..d0a69aa35e27 100644 --- a/arch/ia64/include/asm/barrier.h +++ b/arch/ia64/include/asm/barrier.h @@ -45,14 +45,37 @@ # define smp_rmb() rmb() # define smp_wmb() wmb() # define smp_read_barrier_depends() read_barrier_depends() + #else + # define smp_mb() barrier() # define smp_rmb() barrier() # define smp_wmb() barrier() # define smp_read_barrier_depends() do { } while(0) + #endif /* + * IA64 GCC turns volatile stores into st.rel and volatile loads into ld.acq no + * need for asm trickery! + */ + +#define smp_store_release(p, v) \ +do { \ + compiletime_assert_atomic_type(*p); \ + barrier(); \ + ACCESS_ONCE(*p) = (v); \ +} while (0) + +#define smp_load_acquire(p) \ +({ \ + typeof(*p) ___p1 = ACCESS_ONCE(*p); \ + compiletime_assert_atomic_type(*p); \ + barrier(); \ + ___p1; \ +}) + +/* * XXX check on this ---I suspect what Linus really wants here is * acquire vs release semantics but we can't discuss this stuff with * Linus just yet. Grrr... diff --git a/arch/m32r/include/asm/barrier.h b/arch/m32r/include/asm/barrier.h index 6976621efd3f..1a40265e8d88 100644 --- a/arch/m32r/include/asm/barrier.h +++ b/arch/m32r/include/asm/barrier.h @@ -11,84 +11,6 @@ #define nop() __asm__ __volatile__ ("nop" : : ) -/* - * Memory barrier. - * - * mb() prevents loads and stores being reordered across this point. - * rmb() prevents loads being reordered across this point. - * wmb() prevents stores being reordered across this point. - */ -#define mb() barrier() -#define rmb() mb() -#define wmb() mb() - -/** - * read_barrier_depends - Flush all pending reads that subsequents reads - * depend on. - * - * No data-dependent reads from memory-like regions are ever reordered - * over this barrier. All reads preceding this primitive are guaranteed - * to access memory (but not necessarily other CPUs' caches) before any - * reads following this primitive that depend on the data return by - * any of the preceding reads. This primitive is much lighter weight than - * rmb() on most CPUs, and is never heavier weight than is - * rmb(). - * - * These ordering constraints are respected by both the local CPU - * and the compiler. - * - * Ordering is not guaranteed by anything other than these primitives, - * not even by data dependencies. See the documentation for - * memory_barrier() for examples and URLs to more information. - * - * For example, the following code would force ordering (the initial - * value of "a" is zero, "b" is one, and "p" is "&a"): - * - * <programlisting> - * CPU 0 CPU 1 - * - * b = 2; - * memory_barrier(); - * p = &b; q = p; - * read_barrier_depends(); - * d = *q; - * </programlisting> - * - * - * because the read of "*q" depends on the read of "p" and these - * two reads are separated by a read_barrier_depends(). However, - * the following code, with the same initial values for "a" and "b": - * - * <programlisting> - * CPU 0 CPU 1 - * - * a = 2; - * memory_barrier(); - * b = 3; y = b; - * read_barrier_depends(); - * x = a; - * </programlisting> - * - * does not enforce ordering, since there is no data dependency between - * the read of "a" and the read of "b". Therefore, on some CPUs, such - * as Alpha, "y" could be set to 3 and "x" to 0. Use rmb() - * in cases like this where there are no data dependencies. - **/ - -#define read_barrier_depends() do { } while (0) - -#ifdef CONFIG_SMP -#define smp_mb() mb() -#define smp_rmb() rmb() -#define smp_wmb() wmb() -#define smp_read_barrier_depends() read_barrier_depends() -#define set_mb(var, value) do { (void) xchg(&var, value); } while (0) -#else -#define smp_mb() barrier() -#define smp_rmb() barrier() -#define smp_wmb() barrier() -#define smp_read_barrier_depends() do { } while (0) -#define set_mb(var, value) do { var = value; barrier(); } while (0) -#endif +#include <asm-generic/barrier.h> #endif /* _ASM_M32R_BARRIER_H */ diff --git a/arch/m68k/include/asm/barrier.h b/arch/m68k/include/asm/barrier.h index 445ce22c23cb..15c5f77c1614 100644 --- a/arch/m68k/include/asm/barrier.h +++ b/arch/m68k/include/asm/barrier.h @@ -1,20 +1,8 @@ #ifndef _M68K_BARRIER_H #define _M68K_BARRIER_H -/* - * Force strict CPU ordering. - * Not really required on m68k... - */ #define nop() do { asm volatile ("nop"); barrier(); } while (0) -#define mb() barrier() -#define rmb() barrier() -#define wmb() barrier() -#define read_barrier_depends() ((void)0) -#define set_mb(var, value) ({ (var) = (value); wmb(); }) -#define smp_mb() barrier() -#define smp_rmb() barrier() -#define smp_wmb() barrier() -#define smp_read_barrier_depends() ((void)0) +#include <asm-generic/barrier.h> #endif /* _M68K_BARRIER_H */ diff --git a/arch/metag/include/asm/barrier.h b/arch/metag/include/asm/barrier.h index c90bfc6bf648..5d6b4b407dda 100644 --- a/arch/metag/include/asm/barrier.h +++ b/arch/metag/include/asm/barrier.h @@ -82,4 +82,19 @@ static inline void fence(void) #define smp_read_barrier_depends() do { } while (0) #define set_mb(var, value) do { var = value; smp_mb(); } while (0) +#define smp_store_release(p, v) \ +do { \ + compiletime_assert_atomic_type(*p); \ + smp_mb(); \ + ACCESS_ONCE(*p) = (v); \ +} while (0) + +#define smp_load_acquire(p) \ +({ \ + typeof(*p) ___p1 = ACCESS_ONCE(*p); \ + compiletime_assert_atomic_type(*p); \ + smp_mb(); \ + ___p1; \ +}) + #endif /* _ASM_METAG_BARRIER_H */ diff --git a/arch/microblaze/include/asm/Kbuild b/arch/microblaze/include/asm/Kbuild index ce0bbf8f5640..a82426589fff 100644 --- a/arch/microblaze/include/asm/Kbuild +++ b/arch/microblaze/include/asm/Kbuild @@ -1,4 +1,5 @@ +generic-y += barrier.h generic-y += clkdev.h generic-y += exec.h generic-y += trace_clock.h diff --git a/arch/microblaze/include/asm/barrier.h b/arch/microblaze/include/asm/barrier.h deleted file mode 100644 index df5be3e87044..000000000000 --- a/arch/microblaze/include/asm/barrier.h +++ /dev/null @@ -1,27 +0,0 @@ -/* - * Copyright (C) 2006 Atmark Techno, Inc. - * - * This file is subject to the terms and conditions of the GNU General Public - * License. See the file "COPYING" in the main directory of this archive - * for more details. - */ - -#ifndef _ASM_MICROBLAZE_BARRIER_H -#define _ASM_MICROBLAZE_BARRIER_H - -#define nop() asm volatile ("nop") - -#define smp_read_barrier_depends() do {} while (0) -#define read_barrier_depends() do {} while (0) - -#define mb() barrier() -#define rmb() mb() -#define wmb() mb() -#define set_mb(var, value) do { var = value; mb(); } while (0) -#define set_wmb(var, value) do { var = value; wmb(); } while (0) - -#define smp_mb() mb() -#define smp_rmb() rmb() -#define smp_wmb() wmb() - -#endif /* _ASM_MICROBLAZE_BARRIER_H */ diff --git a/arch/mips/include/asm/barrier.h b/arch/mips/include/asm/barrier.h index f26d8e1bf3c3..e1aa4e4c2984 100644 --- a/arch/mips/include/asm/barrier.h +++ b/arch/mips/include/asm/barrier.h @@ -180,4 +180,19 @@ #define nudge_writes() mb() #endif +#define smp_store_release(p, v) \ +do { \ + compiletime_assert_atomic_type(*p); \ + smp_mb(); \ + ACCESS_ONCE(*p) = (v); \ +} while (0) + +#define smp_load_acquire(p) \ +({ \ + typeof(*p) ___p1 = ACCESS_ONCE(*p); \ + compiletime_assert_atomic_type(*p); \ + smp_mb(); \ + ___p1; \ +}) + #endif /* __ASM_BARRIER_H */ diff --git a/arch/mn10300/include/asm/Kbuild b/arch/mn10300/include/asm/Kbuild index 74742dc6a3da..032143ec2324 100644 --- a/arch/mn10300/include/asm/Kbuild +++ b/arch/mn10300/include/asm/Kbuild @@ -1,4 +1,5 @@ +generic-y += barrier.h generic-y += clkdev.h generic-y += exec.h generic-y += trace_clock.h diff --git a/arch/mn10300/include/asm/barrier.h b/arch/mn10300/include/asm/barrier.h deleted file mode 100644 index 2bd97a5c8af7..000000000000 --- a/arch/mn10300/include/asm/barrier.h +++ /dev/null @@ -1,37 +0,0 @@ -/* MN10300 memory barrier definitions - * - * Copyright (C) 2007 Red Hat, Inc. All Rights Reserved. - * Written by David Howells (dhowells@redhat.com) - * - * This program is free software; you can redistribute it and/or - * modify it under the terms of the GNU General Public Licence - * as published by the Free Software Foundation; either version - * 2 of the Licence, or (at your option) any later version. - */ -#ifndef _ASM_BARRIER_H -#define _ASM_BARRIER_H - -#define nop() asm volatile ("nop") - -#define mb() asm volatile ("": : :"memory") -#define rmb() mb() -#define wmb() asm volatile ("": : :"memory") - -#ifdef CONFIG_SMP -#define smp_mb() mb() -#define smp_rmb() rmb() -#define smp_wmb() wmb() -#define set_mb(var, value) do { xchg(&var, value); } while (0) -#else /* CONFIG_SMP */ -#define smp_mb() barrier() -#define smp_rmb() barrier() -#define smp_wmb() barrier() -#define set_mb(var, value) do { var = value; mb(); } while (0) -#endif /* CONFIG_SMP */ - -#define set_wmb(var, value) do { var = value; wmb(); } while (0) - -#define read_barrier_depends() do {} while (0) -#define smp_read_barrier_depends() do {} while (0) - -#endif /* _ASM_BARRIER_H */ diff --git a/arch/parisc/include/asm/Kbuild b/arch/parisc/include/asm/Kbuild index a603b9ebe54c..34b0be4ca52d 100644 --- a/arch/parisc/include/asm/Kbuild +++ b/arch/parisc/include/asm/Kbuild @@ -1,4 +1,5 @@ +generic-y += barrier.h generic-y += word-at-a-time.h auxvec.h user.h cputime.h emergency-restart.h \ segment.h topology.h vga.h device.h percpu.h hw_irq.h mutex.h \ div64.h irq_regs.h kdebug.h kvm_para.h local64.h local.h param.h \ diff --git a/arch/parisc/include/asm/barrier.h b/arch/parisc/include/asm/barrier.h deleted file mode 100644 index e77d834aa803..000000000000 --- a/arch/parisc/include/asm/barrier.h +++ /dev/null @@ -1,35 +0,0 @@ -#ifndef __PARISC_BARRIER_H -#define __PARISC_BARRIER_H - -/* -** This is simply the barrier() macro from linux/kernel.h but when serial.c -** uses tqueue.h uses smp_mb() defined using barrier(), linux/kernel.h -** hasn't yet been included yet so it fails, thus repeating the macro here. -** -** PA-RISC architecture allows for weakly ordered memory accesses although -** none of the processors use it. There is a strong ordered bit that is -** set in the O-bit of the page directory entry. Operating systems that -** can not tolerate out of order accesses should set this bit when mapping -** pages. The O-bit of the PSW should also be set to 1 (I don't believe any -** of the processor implemented the PSW O-bit). The PCX-W ERS states that -** the TLB O-bit is not implemented so the page directory does not need to -** have the O-bit set when mapping pages (section 3.1). This section also -** states that the PSW Y, Z, G, and O bits are not implemented. -** So it looks like nothing needs to be done for parisc-linux (yet). -** (thanks to chada for the above comment -ggg) -** -** The __asm__ op below simple prevents gcc/ld from reordering -** instructions across the mb() "call". -*/ -#define mb() __asm__ __volatile__("":::"memory") /* barrier() */ -#define rmb() mb() -#define wmb() mb() -#define smp_mb() mb() -#define smp_rmb() mb() -#define smp_wmb() mb() -#define smp_read_barrier_depends() do { } while(0) -#define read_barrier_depends() do { } while(0) - -#define set_mb(var, value) do { var = value; mb(); } while (0) - -#endif /* __PARISC_BARRIER_H */ diff --git a/arch/powerpc/include/asm/barrier.h b/arch/powerpc/include/asm/barrier.h index ae782254e731..f89da808ce31 100644 --- a/arch/powerpc/include/asm/barrier.h +++ b/arch/powerpc/include/asm/barrier.h @@ -45,11 +45,15 @@ # define SMPWMB eieio #endif +#define __lwsync() __asm__ __volatile__ (stringify_in_c(LWSYNC) : : :"memory") + #define smp_mb() mb() -#define smp_rmb() __asm__ __volatile__ (stringify_in_c(LWSYNC) : : :"memory") +#define smp_rmb() __lwsync() #define smp_wmb() __asm__ __volatile__ (stringify_in_c(SMPWMB) : : :"memory") #define smp_read_barrier_depends() read_barrier_depends() #else +#define __lwsync() barrier() + #define smp_mb() barrier() #define smp_rmb() barrier() #define smp_wmb() barrier() @@ -65,4 +69,19 @@ #define data_barrier(x) \ asm volatile("twi 0,%0,0; isync" : : "r" (x) : "memory"); +#define smp_store_release(p, v) \ +do { \ + compiletime_assert_atomic_type(*p); \ + __lwsync(); \ + ACCESS_ONCE(*p) = (v); \ +} while (0) + +#define smp_load_acquire(p) \ +({ \ + typeof(*p) ___p1 = ACCESS_ONCE(*p); \ + compiletime_assert_atomic_type(*p); \ + __lwsync(); \ + ___p1; \ +}) + #endif /* _ASM_POWERPC_BARRIER_H */ diff --git a/arch/powerpc/include/asm/spinlock.h b/arch/powerpc/include/asm/spinlock.h index 5f54a744dcc5..f6e78d63fb6a 100644 --- a/arch/powerpc/include/asm/spinlock.h +++ b/arch/powerpc/include/asm/spinlock.h @@ -28,6 +28,8 @@ #include <asm/synch.h> #include <asm/ppc-opcode.h> +#define smp_mb__after_unlock_lock() smp_mb() /* Full ordering for lock. */ + #define arch_spin_is_locked(x) ((x)->slock != 0) #ifdef CONFIG_PPC64 diff --git a/arch/s390/include/asm/barrier.h b/arch/s390/include/asm/barrier.h index 16760eeb79b0..578680f6207a 100644 --- a/arch/s390/include/asm/barrier.h +++ b/arch/s390/include/asm/barrier.h @@ -32,4 +32,19 @@ #define set_mb(var, value) do { var = value; mb(); } while (0) +#define smp_store_release(p, v) \ +do { \ + compiletime_assert_atomic_type(*p); \ + barrier(); \ + ACCESS_ONCE(*p) = (v); \ +} while (0) + +#define smp_load_acquire(p) \ +({ \ + typeof(*p) ___p1 = ACCESS_ONCE(*p); \ + compiletime_assert_atomic_type(*p); \ + barrier(); \ + ___p1; \ +}) + #endif /* __ASM_BARRIER_H */ diff --git a/arch/score/include/asm/Kbuild b/arch/score/include/asm/Kbuild index f3414ade77a3..fe7471eb0167 100644 --- a/arch/score/include/asm/Kbuild +++ b/arch/score/include/asm/Kbuild @@ -1,6 +1,7 @@ header-y += +generic-y += barrier.h generic-y += clkdev.h generic-y += trace_clock.h generic-y += xor.h diff --git a/arch/score/include/asm/barrier.h b/arch/score/include/asm/barrier.h deleted file mode 100644 index 0eacb6471e6d..000000000000 --- a/arch/score/include/asm/barrier.h +++ /dev/null @@ -1,16 +0,0 @@ -#ifndef _ASM_SCORE_BARRIER_H -#define _ASM_SCORE_BARRIER_H - -#define mb() barrier() -#define rmb() barrier() -#define wmb() barrier() -#define smp_mb() barrier() -#define smp_rmb() barrier() -#define smp_wmb() barrier() - -#define read_barrier_depends() do {} while (0) -#define smp_read_barrier_depends() do {} while (0) - -#define set_mb(var, value) do {var = value; wmb(); } while (0) - -#endif /* _ASM_SCORE_BARRIER_H */ diff --git a/arch/sh/include/asm/barrier.h b/arch/sh/include/asm/barrier.h index 72c103dae300..43715308b068 100644 --- a/arch/sh/include/asm/barrier.h +++ b/arch/sh/include/asm/barrier.h @@ -26,29 +26,14 @@ #if defined(CONFIG_CPU_SH4A) || defined(CONFIG_CPU_SH5) #define mb() __asm__ __volatile__ ("synco": : :"memory") #define rmb() mb() -#define wmb() __asm__ __volatile__ ("synco": : :"memory") +#define wmb() mb() #define ctrl_barrier() __icbi(PAGE_OFFSET) -#define read_barrier_depends() do { } while(0) #else -#define mb() __asm__ __volatile__ ("": : :"memory") -#define rmb() mb() -#define wmb() __asm__ __volatile__ ("": : :"memory") #define ctrl_barrier() __asm__ __volatile__ ("nop;nop;nop;nop;nop;nop;nop;nop") -#define read_barrier_depends() do { } while(0) -#endif - -#ifdef CONFIG_SMP -#define smp_mb() mb() -#define smp_rmb() rmb() -#define smp_wmb() wmb() -#define smp_read_barrier_depends() read_barrier_depends() -#else -#define smp_mb() barrier() -#define smp_rmb() barrier() -#define smp_wmb() barrier() -#define smp_read_barrier_depends() do { } while(0) #endif #define set_mb(var, value) do { (void)xchg(&var, value); } while (0) +#include <asm-generic/barrier.h> + #endif /* __ASM_SH_BARRIER_H */ diff --git a/arch/sparc/include/asm/barrier_32.h b/arch/sparc/include/asm/barrier_32.h index c1b76654ee76..ae69eda288f4 100644 --- a/arch/sparc/include/asm/barrier_32.h +++ b/arch/sparc/include/asm/barrier_32.h @@ -1,15 +1,7 @@ #ifndef __SPARC_BARRIER_H #define __SPARC_BARRIER_H -/* XXX Change this if we ever use a PSO mode kernel. */ -#define mb() __asm__ __volatile__ ("" : : : "memory") -#define rmb() mb() -#define wmb() mb() -#define read_barrier_depends() do { } while(0) -#define set_mb(__var, __value) do { __var = __value; mb(); } while(0) -#define smp_mb() __asm__ __volatile__("":::"memory") -#define smp_rmb() __asm__ __volatile__("":::"memory") -#define smp_wmb() __asm__ __volatile__("":::"memory") -#define smp_read_barrier_depends() do { } while(0) +#include <asm/processor.h> /* for nop() */ +#include <asm-generic/barrier.h> #endif /* !(__SPARC_BARRIER_H) */ diff --git a/arch/sparc/include/asm/barrier_64.h b/arch/sparc/include/asm/barrier_64.h index 95d45986f908..b5aad964558e 100644 --- a/arch/sparc/include/asm/barrier_64.h +++ b/arch/sparc/include/asm/barrier_64.h @@ -53,4 +53,19 @@ do { __asm__ __volatile__("ba,pt %%xcc, 1f\n\t" \ #define smp_read_barrier_depends() do { } while(0) +#define smp_store_release(p, v) \ +do { \ + compiletime_assert_atomic_type(*p); \ + barrier(); \ + ACCESS_ONCE(*p) = (v); \ +} while (0) + +#define smp_load_acquire(p) \ +({ \ + typeof(*p) ___p1 = ACCESS_ONCE(*p); \ + compiletime_assert_atomic_type(*p); \ + barrier(); \ + ___p1; \ +}) + #endif /* !(__SPARC64_BARRIER_H) */ diff --git a/arch/tile/include/asm/barrier.h b/arch/tile/include/asm/barrier.h index a9a73da5865d..b5a05d050a8f 100644 --- a/arch/tile/include/asm/barrier.h +++ b/arch/tile/include/asm/barrier.h @@ -22,59 +22,6 @@ #include <arch/spr_def.h> #include <asm/timex.h> -/* - * read_barrier_depends - Flush all pending reads that subsequents reads - * depend on. - * - * No data-dependent reads from memory-like regions are ever reordered - * over this barrier. All reads preceding this primitive are guaranteed - * to access memory (but not necessarily other CPUs' caches) before any - * reads following this primitive that depend on the data return by - * any of the preceding reads. This primitive is much lighter weight than - * rmb() on most CPUs, and is never heavier weight than is - * rmb(). - * - * These ordering constraints are respected by both the local CPU - * and the compiler. - * - * Ordering is not guaranteed by anything other than these primitives, - * not even by data dependencies. See the documentation for - * memory_barrier() for examples and URLs to more information. - * - * For example, the following code would force ordering (the initial - * value of "a" is zero, "b" is one, and "p" is "&a"): - * - * <programlisting> - * CPU 0 CPU 1 - * - * b = 2; - * memory_barrier(); - * p = &b; q = p; - * read_barrier_depends(); - * d = *q; - * </programlisting> - * - * because the read of "*q" depends on the read of "p" and these - * two reads are separated by a read_barrier_depends(). However, - * the following code, with the same initial values for "a" and "b": - * - * <programlisting> - * CPU 0 CPU 1 - * - * a = 2; - * memory_barrier(); - * b = 3; y = b; - * read_barrier_depends(); - * x = a; - * </programlisting> - * - * does not enforce ordering, since there is no data dependency between - * the read of "a" and the read of "b". Therefore, on some CPUs, such - * as Alpha, "y" could be set to 3 and "x" to 0. Use rmb() - * in cases like this where there are no data dependencies. - */ -#define read_barrier_depends() do { } while (0) - #define __sync() __insn_mf() #include <hv/syscall_public.h> @@ -125,20 +72,7 @@ mb_incoherent(void) #define mb() fast_mb() #define iob() fast_iob() -#ifdef CONFIG_SMP -#define smp_mb() mb() -#define smp_rmb() rmb() -#define smp_wmb() wmb() -#define smp_read_barrier_depends() read_barrier_depends() -#else -#define smp_mb() barrier() -#define smp_rmb() barrier() -#define smp_wmb() barrier() -#define smp_read_barrier_depends() do { } while (0) -#endif - -#define set_mb(var, value) \ - do { var = value; mb(); } while (0) +#include <asm-generic/barrier.h> #endif /* !__ASSEMBLY__ */ #endif /* _ASM_TILE_BARRIER_H */ diff --git a/arch/unicore32/include/asm/barrier.h b/arch/unicore32/include/asm/barrier.h index a6620e5336b6..83d6a520f4bd 100644 --- a/arch/unicore32/include/asm/barrier.h +++ b/arch/unicore32/include/asm/barrier.h @@ -14,15 +14,6 @@ #define dsb() __asm__ __volatile__ ("" : : : "memory") #define dmb() __asm__ __volatile__ ("" : : : "memory") -#define mb() barrier() -#define rmb() barrier() -#define wmb() barrier() -#define smp_mb() barrier() -#define smp_rmb() barrier() -#define smp_wmb() barrier() -#define read_barrier_depends() do { } while (0) -#define smp_read_barrier_depends() do { } while (0) - -#define set_mb(var, value) do { var = value; smp_mb(); } while (0) +#include <asm-generic/barrier.h> #endif /* __UNICORE_BARRIER_H__ */ diff --git a/arch/x86/include/asm/barrier.h b/arch/x86/include/asm/barrier.h index c6cd358a1eec..04a48903b2eb 100644 --- a/arch/x86/include/asm/barrier.h +++ b/arch/x86/include/asm/barrier.h @@ -92,12 +92,53 @@ #endif #define smp_read_barrier_depends() read_barrier_depends() #define set_mb(var, value) do { (void)xchg(&var, value); } while (0) -#else +#else /* !SMP */ #define smp_mb() barrier() #define smp_rmb() barrier() #define smp_wmb() barrier() #define smp_read_barrier_depends() do { } while (0) #define set_mb(var, value) do { var = value; barrier(); } while (0) +#endif /* SMP */ + +#if defined(CONFIG_X86_OOSTORE) || defined(CONFIG_X86_PPRO_FENCE) + +/* + * For either of these options x86 doesn't have a strong TSO memory + * model and we should fall back to full barriers. + */ + +#define smp_store_release(p, v) \ +do { \ + compiletime_assert_atomic_type(*p); \ + smp_mb(); \ + ACCESS_ONCE(*p) = (v); \ +} while (0) + +#define smp_load_acquire(p) \ +({ \ + typeof(*p) ___p1 = ACCESS_ONCE(*p); \ + compiletime_assert_atomic_type(*p); \ + smp_mb(); \ + ___p1; \ +}) + +#else /* regular x86 TSO memory ordering */ + +#define smp_store_release(p, v) \ +do { \ + compiletime_assert_atomic_type(*p); \ + barrier(); \ + ACCESS_ONCE(*p) = (v); \ +} while (0) + +#define smp_load_acquire(p) \ +({ \ + typeof(*p) ___p1 = ACCESS_ONCE(*p); \ + compiletime_assert_atomic_type(*p); \ + barrier(); \ + ___p1; \ +}) + #endif /* diff --git a/arch/xtensa/include/asm/barrier.h b/arch/xtensa/include/asm/barrier.h index ef021677d536..e1ee6b51dfc5 100644 --- a/arch/xtensa/include/asm/barrier.h +++ b/arch/xtensa/include/asm/barrier.h @@ -9,21 +9,14 @@ #ifndef _XTENSA_SYSTEM_H #define _XTENSA_SYSTEM_H -#define smp_read_barrier_depends() do { } while(0) -#define read_barrier_depends() do { } while(0) - #define mb() ({ __asm__ __volatile__("memw" : : : "memory"); }) #define rmb() barrier() #define wmb() mb() #ifdef CONFIG_SMP #error smp_* not defined -#else -#define smp_mb() barrier() -#define smp_rmb() barrier() -#define smp_wmb() barrier() #endif -#define set_mb(var, value) do { var = value; mb(); } while (0) +#include <asm-generic/barrier.h> #endif /* _XTENSA_SYSTEM_H */ |