/*- * Copyright (c) 1998 Doug Rabson * All rights reserved. * * Redistribution and use in source and binary forms, with or without * modification, are permitted provided that the following conditions * are met: * 1. Redistributions of source code must retain the above copyright * notice, this list of conditions and the following disclaimer. * 2. Redistributions in binary form must reproduce the above copyright * notice, this list of conditions and the following disclaimer in the * documentation and/or other materials provided with the distribution. * * THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE * ARE DISCLAIMED. IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF * SUCH DAMAGE. * * $FreeBSD: src/sys/i386/include/atomic.h,v 1.9.2.1 2000/07/07 00:38:47 obrien Exp $ * $DragonFly: src/sys/cpu/i386/include/atomic.h,v 1.25 2008/06/26 23:06:50 dillon Exp $ */ #ifndef _CPU_ATOMIC_H_ #define _CPU_ATOMIC_H_ #ifndef _SYS_TYPES_H_ #include #endif /* * Various simple arithmetic on memory which is atomic in the presence * of interrupts and multiple processors. * * atomic_set_char(P, V) (*(u_char*)(P) |= (V)) * atomic_clear_char(P, V) (*(u_char*)(P) &= ~(V)) * atomic_add_char(P, V) (*(u_char*)(P) += (V)) * atomic_subtract_char(P, V) (*(u_char*)(P) -= (V)) * * atomic_set_short(P, V) (*(u_short*)(P) |= (V)) * atomic_clear_short(P, V) (*(u_short*)(P) &= ~(V)) * atomic_add_short(P, V) (*(u_short*)(P) += (V)) * atomic_subtract_short(P, V) (*(u_short*)(P) -= (V)) * * atomic_set_int(P, V) (*(u_int*)(P) |= (V)) * atomic_clear_int(P, V) (*(u_int*)(P) &= ~(V)) * atomic_add_int(P, V) (*(u_int*)(P) += (V)) * atomic_subtract_int(P, V) (*(u_int*)(P) -= (V)) * * atomic_set_long(P, V) (*(u_long*)(P) |= (V)) * atomic_clear_long(P, V) (*(u_long*)(P) &= ~(V)) * atomic_add_long(P, V) (*(u_long*)(P) += (V)) * atomic_subtract_long(P, V) (*(u_long*)(P) -= (V)) * atomic_readandclear_long(P) (return (*(u_long*)(P)); *(u_long*)(P) = 0;) * atomic_readandclear_int(P) (return (*(u_int*)(P)); *(u_int*)(P) = 0;) */ /* * The above functions are expanded inline in the statically-linked * kernel. Lock prefixes are generated if an SMP kernel is being * built, or if user code is using these functions. * * Kernel modules call real functions which are built into the kernel. * This allows kernel modules to be portable between UP and SMP systems. */ #if defined(KLD_MODULE) #define ATOMIC_ASM(NAME, TYPE, OP, V) \ extern void atomic_##NAME##_##TYPE(volatile u_##TYPE *p, u_##TYPE v); \ extern void atomic_##NAME##_##TYPE##_nonlocked(volatile u_##TYPE *p, u_##TYPE v); #else /* !KLD_MODULE */ #if defined(SMP) || !defined(_KERNEL) #define MPLOCKED "lock ; " #else #define MPLOCKED #endif /* * The assembly is volatilized to demark potential before-and-after side * effects if an interrupt or SMP collision were to occur. The primary * atomic instructions are MP safe, the nonlocked instructions are * local-interrupt-safe (so we don't depend on C 'X |= Y' generating an * atomic instruction). * * +m - memory is read and written (=m - memory is only written) * iq - integer constant or %ax/%bx/%cx/%dx (ir = int constant or any reg) * (Note: byte instructions only work on %ax,%bx,%cx, or %dx). iq * is good enough for our needs so don't get fancy. */ /* egcs 1.1.2+ version */ #define ATOMIC_ASM(NAME, TYPE, OP, V) \ static __inline void \ atomic_##NAME##_##TYPE(volatile u_##TYPE *p, u_##TYPE v)\ { \ __asm __volatile(MPLOCKED OP \ : "+m" (*p) \ : "iq" (V)); \ } \ static __inline void \ atomic_##NAME##_##TYPE##_nonlocked(volatile u_##TYPE *p, u_##TYPE v)\ { \ __asm __volatile(OP \ : "+m" (*p) \ : "iq" (V)); \ } #endif /* KLD_MODULE */ /* egcs 1.1.2+ version */ ATOMIC_ASM(set, char, "orb %b1,%0", v) ATOMIC_ASM(clear, char, "andb %b1,%0", ~v) ATOMIC_ASM(add, char, "addb %b1,%0", v) ATOMIC_ASM(subtract, char, "subb %b1,%0", v) ATOMIC_ASM(set, short, "orw %w1,%0", v) ATOMIC_ASM(clear, short, "andw %w1,%0", ~v) ATOMIC_ASM(add, short, "addw %w1,%0", v) ATOMIC_ASM(subtract, short, "subw %w1,%0", v) ATOMIC_ASM(set, int, "orl %1,%0", v) ATOMIC_ASM(clear, int, "andl %1,%0", ~v) ATOMIC_ASM(add, int, "addl %1,%0", v) ATOMIC_ASM(subtract, int, "subl %1,%0", v) ATOMIC_ASM(set, long, "orq %1,%0", v) ATOMIC_ASM(clear, long, "andq %1,%0", ~v) ATOMIC_ASM(add, long, "addq %1,%0", v) ATOMIC_ASM(subtract, long, "subq %1,%0", v) #if defined(KLD_MODULE) u_long atomic_readandclear_long(volatile u_long *addr); u_int atomic_readandclear_int(volatile u_int *addr); #else /* !KLD_MODULE */ static __inline u_long atomic_readandclear_long(volatile u_long *addr) { u_long res; res = 0; __asm __volatile( " xchgq %1,%0 ; " "# atomic_readandclear_long" : "+r" (res), /* 0 */ "=m" (*addr) /* 1 */ : "m" (*addr)); return (res); } static __inline u_int atomic_readandclear_int(volatile u_int *addr) { u_int res; res = 0; __asm __volatile( " xchgl %1,%0 ; " "# atomic_readandclear_int" : "+r" (res), /* 0 */ "=m" (*addr) /* 1 */ : "m" (*addr)); return (res); } #endif /* KLD_MODULE */ /* * atomic_poll_acquire_int(P) Returns non-zero on success, 0 if the lock * has already been acquired. * atomic_poll_release_int(P) * * These support the NDIS driver and are also used for IPIQ interlocks * between cpus. Both the acquisition and release must be * cache-synchronizing instructions. */ #if defined(KLD_MODULE) extern int atomic_swap_int(volatile int *addr, int value); extern int atomic_poll_acquire_int(volatile u_int *p); extern void atomic_poll_release_int(volatile u_int *p); #else static __inline int atomic_swap_int(volatile int *addr, int value) { __asm __volatile("xchgl %0, %1" : "=r" (value), "=m" (*addr) : "0" (value) : "memory"); return (value); } static __inline int atomic_poll_acquire_int(volatile u_int *p) { u_int data; __asm __volatile(MPLOCKED "btsl $0,%0; setnc %%al; andl $255,%%eax" : "+m" (*p), "=a" (data)); return(data); } static __inline void atomic_poll_release_int(volatile u_int *p) { __asm __volatile(MPLOCKED "btrl $0,%0" : "+m" (*p)); } #endif /* * These functions operate on a 32 bit interrupt interlock which is defined * as follows: * * bit 0-30 interrupt handler disabled bits (counter) * bit 31 interrupt handler currently running bit (1 = run) * * atomic_intr_cond_test(P) Determine if the interlock is in an * acquired state. Returns 0 if it not * acquired, non-zero if it is. * * atomic_intr_cond_try(P) * Increment the request counter and attempt to * set bit 31 to acquire the interlock. If * we are unable to set bit 31 the request * counter is decremented and we return -1, * otherwise we return 0. * * atomic_intr_cond_enter(P, func, arg) * Increment the request counter and attempt to * set bit 31 to acquire the interlock. If * we are unable to set bit 31 func(arg) is * called in a loop until we are able to set * bit 31. * * atomic_intr_cond_exit(P, func, arg) * Decrement the request counter and clear bit * 31. If the request counter is still non-zero * call func(arg) once. * * atomic_intr_handler_disable(P) * Set bit 30, indicating that the interrupt * handler has been disabled. Must be called * after the hardware is disabled. * * Returns bit 31 indicating whether a serialized * accessor is active (typically the interrupt * handler is running). 0 == not active, * non-zero == active. * * atomic_intr_handler_enable(P) * Clear bit 30, indicating that the interrupt * handler has been enabled. Must be called * before the hardware is actually enabled. * * atomic_intr_handler_is_enabled(P) * Returns bit 30, 0 indicates that the handler * is enabled, non-zero indicates that it is * disabled. The request counter portion of * the field is ignored. */ #if defined(KLD_MODULE) void atomic_intr_init(__atomic_intr_t *p); int atomic_intr_handler_disable(__atomic_intr_t *p); void atomic_intr_handler_enable(__atomic_intr_t *p); int atomic_intr_handler_is_enabled(__atomic_intr_t *p); int atomic_intr_cond_test(__atomic_intr_t *p); int atomic_intr_cond_try(__atomic_intr_t *p); void atomic_intr_cond_enter(__atomic_intr_t *p, void (*func)(void *), void *arg); void atomic_intr_cond_exit(__atomic_intr_t *p, void (*func)(void *), void *arg); #else static __inline void atomic_intr_init(__atomic_intr_t *p) { *p = 0; } static __inline int atomic_intr_handler_disable(__atomic_intr_t *p) { int data; __asm __volatile(MPLOCKED "orl $0x40000000,%1; movl %1,%%eax; " \ "andl $0x80000000,%%eax" \ : "=a"(data) , "+m"(*p)); return(data); } static __inline void atomic_intr_handler_enable(__atomic_intr_t *p) { __asm __volatile(MPLOCKED "andl $0xBFFFFFFF,%0" : "+m" (*p)); } static __inline int atomic_intr_handler_is_enabled(__atomic_intr_t *p) { int data; __asm __volatile("movl %1,%%eax; andl $0x40000000,%%eax" \ : "=a"(data) : "m"(*p)); return(data); } static __inline void atomic_intr_cond_enter(__atomic_intr_t *p, void (*func)(void *), void *arg) { __asm __volatile(MPLOCKED "incl %0; " \ "1: ;" \ MPLOCKED "btsl $31,%0; jnc 2f; " \ "movq %2,%%rdi; call *%1; " \ "jmp 1b; " \ "2: ;" \ : "+m" (*p) \ : "r"(func), "m"(arg) \ : "ax", "cx", "dx", "rsi", "rdi", "r8", "r9", "r10", "r11"); /* YYY the function call may clobber even more registers? */ } /* * Attempt to enter the interrupt condition variable. Returns zero on * success, 1 on failure. */ static __inline int atomic_intr_cond_try(__atomic_intr_t *p) { int ret; __asm __volatile(MPLOCKED "incl %0; " \ "1: ;" \ "subl %%eax,%%eax; " \ MPLOCKED "btsl $31,%0; jnc 2f; " \ MPLOCKED "decl %0; " \ "movl $1,%%eax;" \ "2: ;" : "+m" (*p), "=&a"(ret) : : "cx", "dx"); return (ret); } static __inline int atomic_intr_cond_test(__atomic_intr_t *p) { return((int)(*p & 0x80000000)); } static __inline void atomic_intr_cond_exit(__atomic_intr_t *p, void (*func)(void *), void *arg) { __asm __volatile(MPLOCKED "decl %0; " \ MPLOCKED "btrl $31,%0; " \ "testl $0x3FFFFFFF,%0; jz 1f; " \ "movq %2,%%rdi; call *%1; " \ "1: ;" \ : "+m" (*p) \ : "r"(func), "m"(arg) \ : "ax", "cx", "dx", "rsi", "rdi", "r8", "r9", "r10", "r11"); /* YYY the function call may clobber even more registers? */ } #endif /* * Atomic compare and set * * if (*_dst == _old) *_dst = _new (all 32 bit words) * * Returns 0 on failure, non-zero on success. The inline is designed to * allow the compiler to optimize the common case where the caller calls * these functions from inside a conditional. */ #if defined(KLD_MODULE) extern int atomic_cmpset_int(volatile u_int *_dst, u_int _old, u_int _new); extern long atomic_cmpset_long(volatile u_long *_dst, u_long _exp, u_long _src); extern u_int atomic_fetchadd_int(volatile u_int *_p, u_int _v); #else static __inline int atomic_cmpset_int(volatile u_int *_dst, u_int _old, u_int _new) { u_int res = _old; __asm __volatile(MPLOCKED "cmpxchgl %2,%1; " \ : "+a" (res), "=m" (*_dst) \ : "r" (_new), "m" (*_dst) \ : "memory"); return (res == _old); } static __inline long atomic_cmpset_long(volatile u_long *_dst, u_long _old, u_long _new) { u_long res = _old; __asm __volatile(MPLOCKED "cmpxchgq %2,%1; " \ : "+a" (res), "=m" (*_dst) \ : "r" (_new), "m" (*_dst) \ : "memory"); return (res == _old); } /* * Atomically add the value of v to the integer pointed to by p and return * the previous value of *p. */ static __inline u_int atomic_fetchadd_int(volatile u_int *_p, u_int _v) { __asm __volatile(MPLOCKED "xaddl %0,%1; " \ : "+r" (_v), "=m" (*_p) \ : "m" (*_p) \ : "memory"); return (_v); } #endif /* KLD_MODULE */ #if defined(KLD_MODULE) #define ATOMIC_STORE_LOAD(TYPE, LOP, SOP) \ extern u_##TYPE atomic_load_acq_##TYPE(volatile u_##TYPE *p); \ extern void atomic_store_rel_##TYPE(volatile u_##TYPE *p, u_##TYPE v); #else /* !KLD_MODULE */ #if defined(_KERNEL) && !defined(SMP) /* * We assume that a = b will do atomic loads and stores. However, on a * PentiumPro or higher, reads may pass writes, so for that case we have * to use a serializing instruction (i.e. with LOCK) to do the load in * SMP kernels. For UP kernels, however, the cache of the single processor * is always consistent, so we don't need any memory barriers. */ #define ATOMIC_STORE_LOAD(TYPE, LOP, SOP) \ static __inline u_##TYPE \ atomic_load_acq_##TYPE(volatile u_##TYPE *p) \ { \ return (*p); \ } \ \ static __inline void \ atomic_store_rel_##TYPE(volatile u_##TYPE *p, u_##TYPE v)\ { \ *p = v; \ } \ struct __hack #else /* !(_KERNEL && !SMP) */ #define ATOMIC_STORE_LOAD(TYPE, LOP, SOP) \ static __inline u_##TYPE \ atomic_load_acq_##TYPE(volatile u_##TYPE *p) \ { \ u_##TYPE res; \ \ __asm __volatile(MPLOCKED LOP \ : "=a" (res), /* 0 */ \ "=m" (*p) /* 1 */ \ : "m" (*p) /* 2 */ \ : "memory"); \ \ return (res); \ } \ \ /* \ * The XCHG instruction asserts LOCK automagically. \ */ \ static __inline void \ atomic_store_rel_##TYPE(volatile u_##TYPE *p, u_##TYPE v)\ { \ __asm __volatile(SOP \ : "=m" (*p), /* 0 */ \ "+r" (v) /* 1 */ \ : "m" (*p)); /* 2 */ \ } \ struct __hack #endif /* _KERNEL && !SMP */ #endif /* !KLD_MODULE */ ATOMIC_STORE_LOAD(char, "cmpxchgb %b0,%1", "xchgb %b1,%0"); ATOMIC_STORE_LOAD(short,"cmpxchgw %w0,%1", "xchgw %w1,%0"); ATOMIC_STORE_LOAD(int, "cmpxchgl %0,%1", "xchgl %1,%0"); ATOMIC_STORE_LOAD(long, "cmpxchgq %0,%1", "xchgq %1,%0"); #undef ATOMIC_ASM #undef ATOMIC_STORE_LOAD /* Acquire and release variants are identical to the normal ones. */ #define atomic_set_acq_char atomic_set_char #define atomic_set_rel_char atomic_set_char #define atomic_clear_acq_char atomic_clear_char #define atomic_clear_rel_char atomic_clear_char #define atomic_add_acq_char atomic_add_char #define atomic_add_rel_char atomic_add_char #define atomic_subtract_acq_char atomic_subtract_char #define atomic_subtract_rel_char atomic_subtract_char #define atomic_set_acq_short atomic_set_short #define atomic_set_rel_short atomic_set_short #define atomic_clear_acq_short atomic_clear_short #define atomic_clear_rel_short atomic_clear_short #define atomic_add_acq_short atomic_add_short #define atomic_add_rel_short atomic_add_short #define atomic_subtract_acq_short atomic_subtract_short #define atomic_subtract_rel_short atomic_subtract_short #define atomic_set_acq_int atomic_set_int #define atomic_set_rel_int atomic_set_int #define atomic_clear_acq_int atomic_clear_int #define atomic_clear_rel_int atomic_clear_int #define atomic_add_acq_int atomic_add_int #define atomic_add_rel_int atomic_add_int #define atomic_subtract_acq_int atomic_subtract_int #define atomic_subtract_rel_int atomic_subtract_int #define atomic_cmpset_acq_int atomic_cmpset_int #define atomic_cmpset_rel_int atomic_cmpset_int #define atomic_set_acq_long atomic_set_long #define atomic_set_rel_long atomic_set_long #define atomic_clear_acq_long atomic_clear_long #define atomic_clear_rel_long atomic_clear_long #define atomic_add_acq_long atomic_add_long #define atomic_add_rel_long atomic_add_long #define atomic_subtract_acq_long atomic_subtract_long #define atomic_subtract_rel_long atomic_subtract_long #define atomic_cmpset_acq_long atomic_cmpset_long #define atomic_cmpset_rel_long atomic_cmpset_long /* Operations on 8-bit bytes. */ #define atomic_set_8 atomic_set_char #define atomic_set_acq_8 atomic_set_acq_char #define atomic_set_rel_8 atomic_set_rel_char #define atomic_clear_8 atomic_clear_char #define atomic_clear_acq_8 atomic_clear_acq_char #define atomic_clear_rel_8 atomic_clear_rel_char #define atomic_add_8 atomic_add_char #define atomic_add_acq_8 atomic_add_acq_char #define atomic_add_rel_8 atomic_add_rel_char #define atomic_subtract_8 atomic_subtract_char #define atomic_subtract_acq_8 atomic_subtract_acq_char #define atomic_subtract_rel_8 atomic_subtract_rel_char #define atomic_load_acq_8 atomic_load_acq_char #define atomic_store_rel_8 atomic_store_rel_char /* Operations on 16-bit words. */ #define atomic_set_16 atomic_set_short #define atomic_set_acq_16 atomic_set_acq_short #define atomic_set_rel_16 atomic_set_rel_short #define atomic_clear_16 atomic_clear_short #define atomic_clear_acq_16 atomic_clear_acq_short #define atomic_clear_rel_16 atomic_clear_rel_short #define atomic_add_16 atomic_add_short #define atomic_add_acq_16 atomic_add_acq_short #define atomic_add_rel_16 atomic_add_rel_short #define atomic_subtract_16 atomic_subtract_short #define atomic_subtract_acq_16 atomic_subtract_acq_short #define atomic_subtract_rel_16 atomic_subtract_rel_short #define atomic_load_acq_16 atomic_load_acq_short #define atomic_store_rel_16 atomic_store_rel_short /* Operations on 32-bit double words. */ #define atomic_set_32 atomic_set_int #define atomic_set_acq_32 atomic_set_acq_int #define atomic_set_rel_32 atomic_set_rel_int #define atomic_clear_32 atomic_clear_int #define atomic_clear_acq_32 atomic_clear_acq_int #define atomic_clear_rel_32 atomic_clear_rel_int #define atomic_add_32 atomic_add_int #define atomic_add_acq_32 atomic_add_acq_int #define atomic_add_rel_32 atomic_add_rel_int #define atomic_subtract_32 atomic_subtract_int #define atomic_subtract_acq_32 atomic_subtract_acq_int #define atomic_subtract_rel_32 atomic_subtract_rel_int #define atomic_load_acq_32 atomic_load_acq_int #define atomic_store_rel_32 atomic_store_rel_int #define atomic_cmpset_32 atomic_cmpset_int #define atomic_cmpset_acq_32 atomic_cmpset_acq_int #define atomic_cmpset_rel_32 atomic_cmpset_rel_int #define atomic_readandclear_32 atomic_readandclear_int #define atomic_fetchadd_32 atomic_fetchadd_int /* Operations on pointers. */ #define atomic_set_ptr(p, v) \ atomic_set_long((volatile u_long *)(p), (u_long)(v)) #define atomic_set_acq_ptr(p, v) \ atomic_set_acq_long((volatile u_long *)(p), (u_long)(v)) #define atomic_set_rel_ptr(p, v) \ atomic_set_rel_long((volatile u_long *)(p), (u_long)(v)) #define atomic_clear_ptr(p, v) \ atomic_clear_long((volatile u_long *)(p), (u_long)(v)) #define atomic_clear_acq_ptr(p, v) \ atomic_clear_acq_long((volatile u_long *)(p), (u_long)(v)) #define atomic_clear_rel_ptr(p, v) \ atomic_clear_rel_long((volatile u_long *)(p), (u_long)(v)) #define atomic_add_ptr(p, v) \ atomic_add_long((volatile u_long *)(p), (u_long)(v)) #define atomic_add_acq_ptr(p, v) \ atomic_add_acq_long((volatile u_long *)(p), (u_long)(v)) #define atomic_add_rel_ptr(p, v) \ atomic_add_rel_long((volatile u_long *)(p), (u_long)(v)) #define atomic_subtract_ptr(p, v) \ atomic_subtract_long((volatile u_long *)(p), (u_long)(v)) #define atomic_subtract_acq_ptr(p, v) \ atomic_subtract_acq_long((volatile u_long *)(p), (u_long)(v)) #define atomic_subtract_rel_ptr(p, v) \ atomic_subtract_rel_long((volatile u_long *)(p), (u_long)(v)) #define atomic_load_acq_ptr(p) \ atomic_load_acq_long((volatile u_long *)(p)) #define atomic_store_rel_ptr(p, v) \ atomic_store_rel_long((volatile u_long *)(p), (v)) #define atomic_cmpset_ptr(dst, old, new) \ atomic_cmpset_long((volatile u_long *)(dst), (u_long)(old), \ (u_long)(new)) #define atomic_cmpset_acq_ptr(dst, old, new) \ atomic_cmpset_acq_long((volatile u_long *)(dst), (u_long)(old), \ (u_long)(new)) #define atomic_cmpset_rel_ptr(dst, old, new) \ atomic_cmpset_rel_long((volatile u_long *)(dst), (u_long)(old), \ (u_long)(new)) #define atomic_readandclear_ptr(p) \ atomic_readandclear_long((volatile u_long *)(p)) #endif /* ! _CPU_ATOMIC_H_ */