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/Ethereal-msm8939-beta9/arch/mips/include/asm/cmpxchg.h

https://bitbucket.org/MilosStamenkovic95/etherealos
C Header | 246 lines | 207 code | 28 blank | 11 comment | 25 complexity | 16fcf8f72b868deba1b51473e974f187 MD5 | raw file
  1/*
  2 * This file is subject to the terms and conditions of the GNU General Public
  3 * License.  See the file "COPYING" in the main directory of this archive
  4 * for more details.
  5 *
  6 * Copyright (C) 2003, 06, 07 by Ralf Baechle (ralf@linux-mips.org)
  7 */
  8#ifndef __ASM_CMPXCHG_H
  9#define __ASM_CMPXCHG_H
 10
 11#include <linux/bug.h>
 12#include <linux/irqflags.h>
 13#include <asm/war.h>
 14
 15static inline unsigned long __xchg_u32(volatile int * m, unsigned int val)
 16{
 17	__u32 retval;
 18
 19	smp_mb__before_llsc();
 20
 21	if (kernel_uses_llsc && R10000_LLSC_WAR) {
 22		unsigned long dummy;
 23
 24		__asm__ __volatile__(
 25		"	.set	mips3					\n"
 26		"1:	ll	%0, %3			# xchg_u32	\n"
 27		"	.set	mips0					\n"
 28		"	move	%2, %z4					\n"
 29		"	.set	mips3					\n"
 30		"	sc	%2, %1					\n"
 31		"	beqzl	%2, 1b					\n"
 32		"	.set	mips0					\n"
 33		: "=&r" (retval), "=m" (*m), "=&r" (dummy)
 34		: "R" (*m), "Jr" (val)
 35		: "memory");
 36	} else if (kernel_uses_llsc) {
 37		unsigned long dummy;
 38
 39		do {
 40			__asm__ __volatile__(
 41			"	.set	mips3				\n"
 42			"	ll	%0, %3		# xchg_u32	\n"
 43			"	.set	mips0				\n"
 44			"	move	%2, %z4				\n"
 45			"	.set	mips3				\n"
 46			"	sc	%2, %1				\n"
 47			"	.set	mips0				\n"
 48			: "=&r" (retval), "=m" (*m), "=&r" (dummy)
 49			: "R" (*m), "Jr" (val)
 50			: "memory");
 51		} while (unlikely(!dummy));
 52	} else {
 53		unsigned long flags;
 54
 55		raw_local_irq_save(flags);
 56		retval = *m;
 57		*m = val;
 58		raw_local_irq_restore(flags);	/* implies memory barrier  */
 59	}
 60
 61	smp_llsc_mb();
 62
 63	return retval;
 64}
 65
 66#ifdef CONFIG_64BIT
 67static inline __u64 __xchg_u64(volatile __u64 * m, __u64 val)
 68{
 69	__u64 retval;
 70
 71	smp_mb__before_llsc();
 72
 73	if (kernel_uses_llsc && R10000_LLSC_WAR) {
 74		unsigned long dummy;
 75
 76		__asm__ __volatile__(
 77		"	.set	mips3					\n"
 78		"1:	lld	%0, %3			# xchg_u64	\n"
 79		"	move	%2, %z4					\n"
 80		"	scd	%2, %1					\n"
 81		"	beqzl	%2, 1b					\n"
 82		"	.set	mips0					\n"
 83		: "=&r" (retval), "=m" (*m), "=&r" (dummy)
 84		: "R" (*m), "Jr" (val)
 85		: "memory");
 86	} else if (kernel_uses_llsc) {
 87		unsigned long dummy;
 88
 89		do {
 90			__asm__ __volatile__(
 91			"	.set	mips3				\n"
 92			"	lld	%0, %3		# xchg_u64	\n"
 93			"	move	%2, %z4				\n"
 94			"	scd	%2, %1				\n"
 95			"	.set	mips0				\n"
 96			: "=&r" (retval), "=m" (*m), "=&r" (dummy)
 97			: "R" (*m), "Jr" (val)
 98			: "memory");
 99		} while (unlikely(!dummy));
100	} else {
101		unsigned long flags;
102
103		raw_local_irq_save(flags);
104		retval = *m;
105		*m = val;
106		raw_local_irq_restore(flags);	/* implies memory barrier  */
107	}
108
109	smp_llsc_mb();
110
111	return retval;
112}
113#else
114extern __u64 __xchg_u64_unsupported_on_32bit_kernels(volatile __u64 * m, __u64 val);
115#define __xchg_u64 __xchg_u64_unsupported_on_32bit_kernels
116#endif
117
118static inline unsigned long __xchg(unsigned long x, volatile void * ptr, int size)
119{
120	switch (size) {
121	case 4:
122		return __xchg_u32(ptr, x);
123	case 8:
124		return __xchg_u64(ptr, x);
125	}
126
127	return x;
128}
129
130#define xchg(ptr, x)							\
131({									\
132	BUILD_BUG_ON(sizeof(*(ptr)) & ~0xc);				\
133									\
134	((__typeof__(*(ptr)))						\
135		__xchg((unsigned long)(x), (ptr), sizeof(*(ptr))));	\
136})
137
138#define __HAVE_ARCH_CMPXCHG 1
139
140#define __cmpxchg_asm(ld, st, m, old, new)				\
141({									\
142	__typeof(*(m)) __ret;						\
143									\
144	if (kernel_uses_llsc && R10000_LLSC_WAR) {			\
145		__asm__ __volatile__(					\
146		"	.set	push				\n"	\
147		"	.set	noat				\n"	\
148		"	.set	mips3				\n"	\
149		"1:	" ld "	%0, %2		# __cmpxchg_asm \n"	\
150		"	bne	%0, %z3, 2f			\n"	\
151		"	.set	mips0				\n"	\
152		"	move	$1, %z4				\n"	\
153		"	.set	mips3				\n"	\
154		"	" st "	$1, %1				\n"	\
155		"	beqzl	$1, 1b				\n"	\
156		"2:						\n"	\
157		"	.set	pop				\n"	\
158		: "=&r" (__ret), "=R" (*m)				\
159		: "R" (*m), "Jr" (old), "Jr" (new)			\
160		: "memory");						\
161	} else if (kernel_uses_llsc) {					\
162		__asm__ __volatile__(					\
163		"	.set	push				\n"	\
164		"	.set	noat				\n"	\
165		"	.set	mips3				\n"	\
166		"1:	" ld "	%0, %2		# __cmpxchg_asm \n"	\
167		"	bne	%0, %z3, 2f			\n"	\
168		"	.set	mips0				\n"	\
169		"	move	$1, %z4				\n"	\
170		"	.set	mips3				\n"	\
171		"	" st "	$1, %1				\n"	\
172		"	beqz	$1, 1b				\n"	\
173		"	.set	pop				\n"	\
174		"2:						\n"	\
175		: "=&r" (__ret), "=R" (*m)				\
176		: "R" (*m), "Jr" (old), "Jr" (new)			\
177		: "memory");						\
178	} else {							\
179		unsigned long __flags;					\
180									\
181		raw_local_irq_save(__flags);				\
182		__ret = *m;						\
183		if (__ret == old)					\
184			*m = new;					\
185		raw_local_irq_restore(__flags);				\
186	}								\
187									\
188	__ret;								\
189})
190
191/*
192 * This function doesn't exist, so you'll get a linker error
193 * if something tries to do an invalid cmpxchg().
194 */
195extern void __cmpxchg_called_with_bad_pointer(void);
196
197#define __cmpxchg(ptr, old, new, pre_barrier, post_barrier)		\
198({									\
199	__typeof__(ptr) __ptr = (ptr);					\
200	__typeof__(*(ptr)) __old = (old);				\
201	__typeof__(*(ptr)) __new = (new);				\
202	__typeof__(*(ptr)) __res = 0;					\
203									\
204	pre_barrier;							\
205									\
206	switch (sizeof(*(__ptr))) {					\
207	case 4:								\
208		__res = __cmpxchg_asm("ll", "sc", __ptr, __old, __new); \
209		break;							\
210	case 8:								\
211		if (sizeof(long) == 8) {				\
212			__res = __cmpxchg_asm("lld", "scd", __ptr,	\
213					   __old, __new);		\
214			break;						\
215		}							\
216	default:							\
217		__cmpxchg_called_with_bad_pointer();			\
218		break;							\
219	}								\
220									\
221	post_barrier;							\
222									\
223	__res;								\
224})
225
226#define cmpxchg(ptr, old, new)		__cmpxchg(ptr, old, new, smp_mb__before_llsc(), smp_llsc_mb())
227#define cmpxchg_local(ptr, old, new)	__cmpxchg(ptr, old, new, , )
228
229#define cmpxchg64(ptr, o, n)						\
230  ({									\
231	BUILD_BUG_ON(sizeof(*(ptr)) != 8);				\
232	cmpxchg((ptr), (o), (n));					\
233  })
234
235#ifdef CONFIG_64BIT
236#define cmpxchg64_local(ptr, o, n)					\
237  ({									\
238	BUILD_BUG_ON(sizeof(*(ptr)) != 8);				\
239	cmpxchg_local((ptr), (o), (n));					\
240  })
241#else
242#include <asm-generic/cmpxchg-local.h>
243#define cmpxchg64_local(ptr, o, n) __cmpxchg64_local_generic((ptr), (o), (n))
244#endif
245
246#endif /* __ASM_CMPXCHG_H */