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Diffstat (limited to 'arch/tile/include/asm/atomic_32.h')
| -rw-r--r-- | arch/tile/include/asm/atomic_32.h | 353 |
1 files changed, 353 insertions, 0 deletions
diff --git a/arch/tile/include/asm/atomic_32.h b/arch/tile/include/asm/atomic_32.h new file mode 100644 index 000000000000..e4f8b4f04895 --- /dev/null +++ b/arch/tile/include/asm/atomic_32.h @@ -0,0 +1,353 @@ +/* + * Copyright 2010 Tilera Corporation. All Rights Reserved. + * + * 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, version 2. + * + * This program is distributed in the hope that it will be useful, but + * WITHOUT ANY WARRANTY; without even the implied warranty of + * MERCHANTABILITY OR FITNESS FOR A PARTICULAR PURPOSE, GOOD TITLE or + * NON INFRINGEMENT. See the GNU General Public License for + * more details. + * + * Do not include directly; use <asm/atomic.h>. + */ + +#ifndef _ASM_TILE_ATOMIC_32_H +#define _ASM_TILE_ATOMIC_32_H + +#include <arch/chip.h> + +#ifndef __ASSEMBLY__ + +/* Tile-specific routines to support <asm/atomic.h>. */ +int _atomic_xchg(atomic_t *v, int n); +int _atomic_xchg_add(atomic_t *v, int i); +int _atomic_xchg_add_unless(atomic_t *v, int a, int u); +int _atomic_cmpxchg(atomic_t *v, int o, int n); + +/** + * atomic_xchg - atomically exchange contents of memory with a new value + * @v: pointer of type atomic_t + * @i: integer value to store in memory + * + * Atomically sets @v to @i and returns old @v + */ +static inline int atomic_xchg(atomic_t *v, int n) +{ + smp_mb(); /* barrier for proper semantics */ + return _atomic_xchg(v, n); +} + +/** + * atomic_cmpxchg - atomically exchange contents of memory if it matches + * @v: pointer of type atomic_t + * @o: old value that memory should have + * @n: new value to write to memory if it matches + * + * Atomically checks if @v holds @o and replaces it with @n if so. + * Returns the old value at @v. + */ +static inline int atomic_cmpxchg(atomic_t *v, int o, int n) +{ + smp_mb(); /* barrier for proper semantics */ + return _atomic_cmpxchg(v, o, n); +} + +/** + * atomic_add - add integer to atomic variable + * @i: integer value to add + * @v: pointer of type atomic_t + * + * Atomically adds @i to @v. + */ +static inline void atomic_add(int i, atomic_t *v) +{ + _atomic_xchg_add(v, i); +} + +/** + * atomic_add_return - add integer and return + * @v: pointer of type atomic_t + * @i: integer value to add + * + * Atomically adds @i to @v and returns @i + @v + */ +static inline int atomic_add_return(int i, atomic_t *v) +{ + smp_mb(); /* barrier for proper semantics */ + return _atomic_xchg_add(v, i) + i; +} + +/** + * atomic_add_unless - add unless the number is already a given value + * @v: pointer of type atomic_t + * @a: the amount to add to v... + * @u: ...unless v is equal to u. + * + * Atomically adds @a to @v, so long as @v was not already @u. + * Returns non-zero if @v was not @u, and zero otherwise. + */ +static inline int atomic_add_unless(atomic_t *v, int a, int u) +{ + smp_mb(); /* barrier for proper semantics */ + return _atomic_xchg_add_unless(v, a, u) != u; +} + +/** + * atomic_set - set atomic variable + * @v: pointer of type atomic_t + * @i: required value + * + * Atomically sets the value of @v to @i. + * + * atomic_set() can't be just a raw store, since it would be lost if it + * fell between the load and store of one of the other atomic ops. + */ +static inline void atomic_set(atomic_t *v, int n) +{ + _atomic_xchg(v, n); +} + +#define xchg(ptr, x) ((typeof(*(ptr))) \ + ((sizeof(*(ptr)) == sizeof(atomic_t)) ? \ + atomic_xchg((atomic_t *)(ptr), (long)(x)) : \ + __xchg_called_with_bad_pointer())) + +#define cmpxchg(ptr, o, n) ((typeof(*(ptr))) \ + ((sizeof(*(ptr)) == sizeof(atomic_t)) ? \ + atomic_cmpxchg((atomic_t *)(ptr), (long)(o), (long)(n)) : \ + __cmpxchg_called_with_bad_pointer())) + +/* A 64bit atomic type */ + +typedef struct { + u64 __aligned(8) counter; +} atomic64_t; + +#define ATOMIC64_INIT(val) { (val) } + +u64 _atomic64_xchg(atomic64_t *v, u64 n); +u64 _atomic64_xchg_add(atomic64_t *v, u64 i); +u64 _atomic64_xchg_add_unless(atomic64_t *v, u64 a, u64 u); +u64 _atomic64_cmpxchg(atomic64_t *v, u64 o, u64 n); + +/** + * atomic64_read - read atomic variable + * @v: pointer of type atomic64_t + * + * Atomically reads the value of @v. + */ +static inline u64 atomic64_read(const atomic64_t *v) +{ + /* + * Requires an atomic op to read both 32-bit parts consistently. + * Casting away const is safe since the atomic support routines + * do not write to memory if the value has not been modified. + */ + return _atomic64_xchg_add((atomic64_t *)v, 0); +} + +/** + * atomic64_xchg - atomically exchange contents of memory with a new value + * @v: pointer of type atomic64_t + * @i: integer value to store in memory + * + * Atomically sets @v to @i and returns old @v + */ +static inline u64 atomic64_xchg(atomic64_t *v, u64 n) +{ + smp_mb(); /* barrier for proper semantics */ + return _atomic64_xchg(v, n); +} + +/** + * atomic64_cmpxchg - atomically exchange contents of memory if it matches + * @v: pointer of type atomic64_t + * @o: old value that memory should have + * @n: new value to write to memory if it matches + * + * Atomically checks if @v holds @o and replaces it with @n if so. + * Returns the old value at @v. + */ +static inline u64 atomic64_cmpxchg(atomic64_t *v, u64 o, u64 n) +{ + smp_mb(); /* barrier for proper semantics */ + return _atomic64_cmpxchg(v, o, n); +} + +/** + * atomic64_add - add integer to atomic variable + * @i: integer value to add + * @v: pointer of type atomic64_t + * + * Atomically adds @i to @v. + */ +static inline void atomic64_add(u64 i, atomic64_t *v) +{ + _atomic64_xchg_add(v, i); +} + +/** + * atomic64_add_return - add integer and return + * @v: pointer of type atomic64_t + * @i: integer value to add + * + * Atomically adds @i to @v and returns @i + @v + */ +static inline u64 atomic64_add_return(u64 i, atomic64_t *v) +{ + smp_mb(); /* barrier for proper semantics */ + return _atomic64_xchg_add(v, i) + i; +} + +/** + * atomic64_add_unless - add unless the number is already a given value + * @v: pointer of type atomic64_t + * @a: the amount to add to v... + * @u: ...unless v is equal to u. + * + * Atomically adds @a to @v, so long as @v was not already @u. + * Returns non-zero if @v was not @u, and zero otherwise. + */ +static inline u64 atomic64_add_unless(atomic64_t *v, u64 a, u64 u) +{ + smp_mb(); /* barrier for proper semantics */ + return _atomic64_xchg_add_unless(v, a, u) != u; +} + +/** + * atomic64_set - set atomic variable + * @v: pointer of type atomic64_t + * @i: required value + * + * Atomically sets the value of @v to @i. + * + * atomic64_set() can't be just a raw store, since it would be lost if it + * fell between the load and store of one of the other atomic ops. + */ +static inline void atomic64_set(atomic64_t *v, u64 n) +{ + _atomic64_xchg(v, n); +} + +#define atomic64_add_negative(a, v) (atomic64_add_return((a), (v)) < 0) +#define atomic64_inc(v) atomic64_add(1LL, (v)) +#define atomic64_inc_return(v) atomic64_add_return(1LL, (v)) +#define atomic64_inc_and_test(v) (atomic64_inc_return(v) == 0) +#define atomic64_sub_return(i, v) atomic64_add_return(-(i), (v)) +#define atomic64_sub_and_test(a, v) (atomic64_sub_return((a), (v)) == 0) +#define atomic64_sub(i, v) atomic64_add(-(i), (v)) +#define atomic64_dec(v) atomic64_sub(1LL, (v)) +#define atomic64_dec_return(v) atomic64_sub_return(1LL, (v)) +#define atomic64_dec_and_test(v) (atomic64_dec_return((v)) == 0) +#define atomic64_inc_not_zero(v) atomic64_add_unless((v), 1LL, 0LL) + +/* + * We need to barrier before modifying the word, since the _atomic_xxx() + * routines just tns the lock and then read/modify/write of the word. + * But after the word is updated, the routine issues an "mf" before returning, + * and since it's a function call, we don't even need a compiler barrier. + */ +#define smp_mb__before_atomic_dec() smp_mb() +#define smp_mb__before_atomic_inc() smp_mb() +#define smp_mb__after_atomic_dec() do { } while (0) +#define smp_mb__after_atomic_inc() do { } while (0) + + +/* + * Support "tns" atomic integers. These are atomic integers that can + * hold any value but "1". They are more efficient than regular atomic + * operations because the "lock" (aka acquire) step is a single "tns" + * in the uncontended case, and the "unlock" (aka release) step is a + * single "store" without an mf. (However, note that on tilepro the + * "tns" will evict the local cache line, so it's not all upside.) + * + * Note that you can ONLY observe the value stored in the pointer + * using these operations; a direct read of the value may confusingly + * return the special value "1". + */ + +int __tns_atomic_acquire(atomic_t *); +void __tns_atomic_release(atomic_t *p, int v); + +static inline void tns_atomic_set(atomic_t *v, int i) +{ + __tns_atomic_acquire(v); + __tns_atomic_release(v, i); +} + +static inline int tns_atomic_cmpxchg(atomic_t *v, int o, int n) +{ + int ret = __tns_atomic_acquire(v); + __tns_atomic_release(v, (ret == o) ? n : ret); + return ret; +} + +static inline int tns_atomic_xchg(atomic_t *v, int n) +{ + int ret = __tns_atomic_acquire(v); + __tns_atomic_release(v, n); + return ret; +} + +#endif /* !__ASSEMBLY__ */ + +/* + * Internal definitions only beyond this point. + */ + +#define ATOMIC_LOCKS_FOUND_VIA_TABLE() \ + (!CHIP_HAS_CBOX_HOME_MAP() && defined(CONFIG_SMP)) + +#if ATOMIC_LOCKS_FOUND_VIA_TABLE() + +/* Number of entries in atomic_lock_ptr[]. */ +#define ATOMIC_HASH_L1_SHIFT 6 +#define ATOMIC_HASH_L1_SIZE (1 << ATOMIC_HASH_L1_SHIFT) + +/* Number of locks in each struct pointed to by atomic_lock_ptr[]. */ +#define ATOMIC_HASH_L2_SHIFT (CHIP_L2_LOG_LINE_SIZE() - 2) +#define ATOMIC_HASH_L2_SIZE (1 << ATOMIC_HASH_L2_SHIFT) + +#else /* ATOMIC_LOCKS_FOUND_VIA_TABLE() */ + +/* + * Number of atomic locks in atomic_locks[]. Must be a power of two. + * There is no reason for more than PAGE_SIZE / 8 entries, since that + * is the maximum number of pointer bits we can use to index this. + * And we cannot have more than PAGE_SIZE / 4, since this has to + * fit on a single page and each entry takes 4 bytes. + */ +#define ATOMIC_HASH_SHIFT (PAGE_SHIFT - 3) +#define ATOMIC_HASH_SIZE (1 << ATOMIC_HASH_SHIFT) + +#ifndef __ASSEMBLY__ +extern int atomic_locks[]; +#endif + +#endif /* ATOMIC_LOCKS_FOUND_VIA_TABLE() */ + +/* + * All the code that may fault while holding an atomic lock must + * place the pointer to the lock in ATOMIC_LOCK_REG so the fault code + * can correctly release and reacquire the lock. Note that we + * mention the register number in a comment in "lib/atomic_asm.S" to help + * assembly coders from using this register by mistake, so if it + * is changed here, change that comment as well. + */ +#define ATOMIC_LOCK_REG 20 +#define ATOMIC_LOCK_REG_NAME r20 + +#ifndef __ASSEMBLY__ +/* Called from setup to initialize a hash table to point to per_cpu locks. */ +void __init_atomic_per_cpu(void); + +#ifdef CONFIG_SMP +/* Support releasing the atomic lock in do_page_fault_ics(). */ +void __atomic_fault_unlock(int *lock_ptr); +#endif +#endif /* !__ASSEMBLY__ */ + +#endif /* _ASM_TILE_ATOMIC_32_H */ |
