From 4f81ca13532981192c83da95ed8c8cb285817d99 Mon Sep 17 00:00:00 2001 From: Mark Salter Date: Wed, 27 Oct 2010 17:28:52 +0100 Subject: [PATCH] MN10300: Implement atomic ops using atomic ops unit Implement atomic ops using the atomic ops unit available in the AM34 CPU. This allows the equivalent of the LL/SC instructions to be found on other CPUs. Signed-off-by: Mark Salter Signed-off-by: David Howells --- arch/mn10300/include/asm/atomic.h | 350 ++++++++++++++++++++++++++++++ arch/mn10300/include/asm/system.h | 48 +--- 2 files changed, 351 insertions(+), 47 deletions(-) diff --git a/arch/mn10300/include/asm/atomic.h b/arch/mn10300/include/asm/atomic.h index f0cc1f84a72f..92d2f9298e38 100644 --- a/arch/mn10300/include/asm/atomic.h +++ b/arch/mn10300/include/asm/atomic.h @@ -1 +1,351 @@ +/* MN10300 Atomic counter operations + * + * 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_ATOMIC_H +#define _ASM_ATOMIC_H + +#include + +#ifndef __ASSEMBLY__ + +#ifdef CONFIG_SMP +#ifdef CONFIG_MN10300_HAS_ATOMIC_OPS_UNIT +static inline +unsigned long __xchg(volatile unsigned long *m, unsigned long val) +{ + unsigned long status; + unsigned long oldval; + + asm volatile( + "1: mov %4,(_AAR,%3) \n" + " mov (_ADR,%3),%1 \n" + " mov %5,(_ADR,%3) \n" + " mov (_ADR,%3),%0 \n" /* flush */ + " mov (_ASR,%3),%0 \n" + " or %0,%0 \n" + " bne 1b \n" + : "=&r"(status), "=&r"(oldval), "=m"(*m) + : "a"(ATOMIC_OPS_BASE_ADDR), "r"(m), "r"(val) + : "memory", "cc"); + + return oldval; +} + +static inline unsigned long __cmpxchg(volatile unsigned long *m, + unsigned long old, unsigned long new) +{ + unsigned long status; + unsigned long oldval; + + asm volatile( + "1: mov %4,(_AAR,%3) \n" + " mov (_ADR,%3),%1 \n" + " cmp %5,%1 \n" + " bne 2f \n" + " mov %6,(_ADR,%3) \n" + "2: mov (_ADR,%3),%0 \n" /* flush */ + " mov (_ASR,%3),%0 \n" + " or %0,%0 \n" + " bne 1b \n" + : "=&r"(status), "=&r"(oldval), "=m"(*m) + : "a"(ATOMIC_OPS_BASE_ADDR), "r"(m), + "r"(old), "r"(new) + : "memory", "cc"); + + return oldval; +} +#else /* CONFIG_MN10300_HAS_ATOMIC_OPS_UNIT */ +#error "No SMP atomic operation support!" +#endif /* CONFIG_MN10300_HAS_ATOMIC_OPS_UNIT */ + +#else /* CONFIG_SMP */ + +/* + * Emulate xchg for non-SMP MN10300 + */ +struct __xchg_dummy { unsigned long a[100]; }; +#define __xg(x) ((struct __xchg_dummy *)(x)) + +static inline +unsigned long __xchg(volatile unsigned long *m, unsigned long val) +{ + unsigned long oldval; + unsigned long flags; + + flags = arch_local_cli_save(); + oldval = *m; + *m = val; + arch_local_irq_restore(flags); + return oldval; +} + +/* + * Emulate cmpxchg for non-SMP MN10300 + */ +static inline unsigned long __cmpxchg(volatile unsigned long *m, + unsigned long old, unsigned long new) +{ + unsigned long oldval; + unsigned long flags; + + flags = arch_local_cli_save(); + oldval = *m; + if (oldval == old) + *m = new; + arch_local_irq_restore(flags); + return oldval; +} + +#endif /* CONFIG_SMP */ + +#define xchg(ptr, v) \ + ((__typeof__(*(ptr))) __xchg((unsigned long *)(ptr), \ + (unsigned long)(v))) + +#define cmpxchg(ptr, o, n) \ + ((__typeof__(*(ptr))) __cmpxchg((unsigned long *)(ptr), \ + (unsigned long)(o), \ + (unsigned long)(n))) + +#define atomic_xchg(ptr, v) (xchg(&(ptr)->counter, (v))) +#define atomic_cmpxchg(v, old, new) (cmpxchg(&((v)->counter), (old), (new))) + +#endif /* !__ASSEMBLY__ */ + +#ifndef CONFIG_SMP #include +#else + +/* + * Atomic operations that C can't guarantee us. Useful for + * resource counting etc.. + */ + +#define ATOMIC_INIT(i) { (i) } + +#ifdef __KERNEL__ + +/** + * atomic_read - read atomic variable + * @v: pointer of type atomic_t + * + * Atomically reads the value of @v. Note that the guaranteed + * useful range of an atomic_t is only 24 bits. + */ +#define atomic_read(v) ((v)->counter) + +/** + * atomic_set - set atomic variable + * @v: pointer of type atomic_t + * @i: required value + * + * Atomically sets the value of @v to @i. Note that the guaranteed + * useful range of an atomic_t is only 24 bits. + */ +#define atomic_set(v, i) (((v)->counter) = (i)) + +/** + * atomic_add_return - add integer to atomic variable + * @i: integer value to add + * @v: pointer of type atomic_t + * + * Atomically adds @i to @v and returns the result + * Note that the guaranteed useful range of an atomic_t is only 24 bits. + */ +static inline int atomic_add_return(int i, atomic_t *v) +{ + int retval; +#ifdef CONFIG_SMP + int status; + + asm volatile( + "1: mov %4,(_AAR,%3) \n" + " mov (_ADR,%3),%1 \n" + " add %5,%1 \n" + " mov %1,(_ADR,%3) \n" + " mov (_ADR,%3),%0 \n" /* flush */ + " mov (_ASR,%3),%0 \n" + " or %0,%0 \n" + " bne 1b \n" + : "=&r"(status), "=&r"(retval), "=m"(v->counter) + : "a"(ATOMIC_OPS_BASE_ADDR), "r"(&v->counter), "r"(i) + : "memory", "cc"); + +#else + unsigned long flags; + + flags = arch_local_cli_save(); + retval = v->counter; + retval += i; + v->counter = retval; + arch_local_irq_restore(flags); +#endif + return retval; +} + +/** + * atomic_sub_return - subtract integer from atomic variable + * @i: integer value to subtract + * @v: pointer of type atomic_t + * + * Atomically subtracts @i from @v and returns the result + * Note that the guaranteed useful range of an atomic_t is only 24 bits. + */ +static inline int atomic_sub_return(int i, atomic_t *v) +{ + int retval; +#ifdef CONFIG_SMP + int status; + + asm volatile( + "1: mov %4,(_AAR,%3) \n" + " mov (_ADR,%3),%1 \n" + " sub %5,%1 \n" + " mov %1,(_ADR,%3) \n" + " mov (_ADR,%3),%0 \n" /* flush */ + " mov (_ASR,%3),%0 \n" + " or %0,%0 \n" + " bne 1b \n" + : "=&r"(status), "=&r"(retval), "=m"(v->counter) + : "a"(ATOMIC_OPS_BASE_ADDR), "r"(&v->counter), "r"(i) + : "memory", "cc"); + +#else + unsigned long flags; + flags = arch_local_cli_save(); + retval = v->counter; + retval -= i; + v->counter = retval; + arch_local_irq_restore(flags); +#endif + return retval; +} + +static inline int atomic_add_negative(int i, atomic_t *v) +{ + return atomic_add_return(i, v) < 0; +} + +static inline void atomic_add(int i, atomic_t *v) +{ + atomic_add_return(i, v); +} + +static inline void atomic_sub(int i, atomic_t *v) +{ + atomic_sub_return(i, v); +} + +static inline void atomic_inc(atomic_t *v) +{ + atomic_add_return(1, v); +} + +static inline void atomic_dec(atomic_t *v) +{ + atomic_sub_return(1, v); +} + +#define atomic_dec_return(v) atomic_sub_return(1, (v)) +#define atomic_inc_return(v) atomic_add_return(1, (v)) + +#define atomic_sub_and_test(i, v) (atomic_sub_return((i), (v)) == 0) +#define atomic_dec_and_test(v) (atomic_sub_return(1, (v)) == 0) +#define atomic_inc_and_test(v) (atomic_add_return(1, (v)) == 0) + +#define atomic_add_unless(v, a, u) \ +({ \ + int c, old; \ + c = atomic_read(v); \ + while (c != (u) && (old = atomic_cmpxchg((v), c, c + (a))) != c) \ + c = old; \ + c != (u); \ +}) + +#define atomic_inc_not_zero(v) atomic_add_unless((v), 1, 0) + +/** + * atomic_clear_mask - Atomically clear bits in memory + * @mask: Mask of the bits to be cleared + * @v: pointer to word in memory + * + * Atomically clears the bits set in mask from the memory word specified. + */ +static inline void atomic_clear_mask(unsigned long mask, unsigned long *addr) +{ +#ifdef CONFIG_SMP + int status; + + asm volatile( + "1: mov %3,(_AAR,%2) \n" + " mov (_ADR,%2),%0 \n" + " and %4,%0 \n" + " mov %0,(_ADR,%2) \n" + " mov (_ADR,%2),%0 \n" /* flush */ + " mov (_ASR,%2),%0 \n" + " or %0,%0 \n" + " bne 1b \n" + : "=&r"(status), "=m"(*addr) + : "a"(ATOMIC_OPS_BASE_ADDR), "r"(addr), "r"(~mask) + : "memory", "cc"); +#else + unsigned long flags; + + mask = ~mask; + flags = arch_local_cli_save(); + *addr &= mask; + arch_local_irq_restore(flags); +#endif +} + +/** + * atomic_set_mask - Atomically set bits in memory + * @mask: Mask of the bits to be set + * @v: pointer to word in memory + * + * Atomically sets the bits set in mask from the memory word specified. + */ +static inline void atomic_set_mask(unsigned long mask, unsigned long *addr) +{ +#ifdef CONFIG_SMP + int status; + + asm volatile( + "1: mov %3,(_AAR,%2) \n" + " mov (_ADR,%2),%0 \n" + " or %4,%0 \n" + " mov %0,(_ADR,%2) \n" + " mov (_ADR,%2),%0 \n" /* flush */ + " mov (_ASR,%2),%0 \n" + " or %0,%0 \n" + " bne 1b \n" + : "=&r"(status), "=m"(*addr) + : "a"(ATOMIC_OPS_BASE_ADDR), "r"(addr), "r"(mask) + : "memory", "cc"); +#else + unsigned long flags; + + flags = arch_local_cli_save(); + *addr |= mask; + arch_local_irq_restore(flags); +#endif +} + +/* Atomic operations are already serializing on MN10300??? */ +#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() + +#include + +#endif /* __KERNEL__ */ +#endif /* CONFIG_SMP */ +#endif /* _ASM_ATOMIC_H */ diff --git a/arch/mn10300/include/asm/system.h b/arch/mn10300/include/asm/system.h index 3c272a1a1015..7de90bc4cf80 100644 --- a/arch/mn10300/include/asm/system.h +++ b/arch/mn10300/include/asm/system.h @@ -18,6 +18,7 @@ #include #include +#include #if !defined(CONFIG_LAZY_SAVE_FPU) struct fpu_state_struct; @@ -96,52 +97,5 @@ do { \ #define read_barrier_depends() do {} while (0) #define smp_read_barrier_depends() do {} while (0) -/*****************************************************************************/ -/* - * MN10300 doesn't actually have an exchange instruction - */ -#ifndef __ASSEMBLY__ - -struct __xchg_dummy { unsigned long a[100]; }; -#define __xg(x) ((struct __xchg_dummy *)(x)) - -static inline -unsigned long __xchg(volatile unsigned long *m, unsigned long val) -{ - unsigned long retval; - unsigned long flags; - - local_irq_save(flags); - retval = *m; - *m = val; - local_irq_restore(flags); - return retval; -} - -#define xchg(ptr, v) \ - ((__typeof__(*(ptr))) __xchg((unsigned long *)(ptr), \ - (unsigned long)(v))) - -static inline unsigned long __cmpxchg(volatile unsigned long *m, - unsigned long old, unsigned long new) -{ - unsigned long retval; - unsigned long flags; - - local_irq_save(flags); - retval = *m; - if (retval == old) - *m = new; - local_irq_restore(flags); - return retval; -} - -#define cmpxchg(ptr, o, n) \ - ((__typeof__(*(ptr))) __cmpxchg((unsigned long *)(ptr), \ - (unsigned long)(o), \ - (unsigned long)(n))) - -#endif /* !__ASSEMBLY__ */ - #endif /* __KERNEL__ */ #endif /* _ASM_SYSTEM_H */