Linux kernel mirror (for testing)
git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git
tjh.dev
kernel
os
linux
1/* system.h: FR-V CPU control definitions
2 *
3 * Copyright (C) 2003 Red Hat, Inc. All Rights Reserved.
4 * Written by David Howells (dhowells@redhat.com)
5 *
6 * This program is free software; you can redistribute it and/or
7 * modify it under the terms of the GNU General Public License
8 * as published by the Free Software Foundation; either version
9 * 2 of the License, or (at your option) any later version.
10 */
11
12#ifndef _ASM_SYSTEM_H
13#define _ASM_SYSTEM_H
14
15#include <linux/types.h>
16#include <linux/linkage.h>
17#include <linux/kernel.h>
18
19struct thread_struct;
20
21/*
22 * switch_to(prev, next) should switch from task `prev' to `next'
23 * `prev' will never be the same as `next'.
24 * The `mb' is to tell GCC not to cache `current' across this call.
25 */
26extern asmlinkage
27struct task_struct *__switch_to(struct thread_struct *prev_thread,
28 struct thread_struct *next_thread,
29 struct task_struct *prev);
30
31#define switch_to(prev, next, last) \
32do { \
33 (prev)->thread.sched_lr = \
34 (unsigned long) __builtin_return_address(0); \
35 (last) = __switch_to(&(prev)->thread, &(next)->thread, (prev)); \
36 mb(); \
37} while(0)
38
39/*
40 * Force strict CPU ordering.
41 */
42#define nop() asm volatile ("nop"::)
43#define mb() asm volatile ("membar" : : :"memory")
44#define rmb() asm volatile ("membar" : : :"memory")
45#define wmb() asm volatile ("membar" : : :"memory")
46#define read_barrier_depends() do { } while (0)
47
48#define smp_mb() barrier()
49#define smp_rmb() barrier()
50#define smp_wmb() barrier()
51#define smp_read_barrier_depends() do {} while(0)
52#define set_mb(var, value) \
53 do { var = (value); barrier(); } while (0)
54
55extern void die_if_kernel(const char *, ...) __attribute__((format(printf, 1, 2)));
56extern void free_initmem(void);
57
58#define arch_align_stack(x) (x)
59
60/*****************************************************************************/
61/*
62 * compare and conditionally exchange value with memory
63 * - if (*ptr == test) then orig = *ptr; *ptr = test;
64 * - if (*ptr != test) then orig = *ptr;
65 */
66extern uint64_t __cmpxchg_64(uint64_t test, uint64_t new, volatile uint64_t *v);
67
68#ifndef CONFIG_FRV_OUTOFLINE_ATOMIC_OPS
69
70#define cmpxchg(ptr, test, new) \
71({ \
72 __typeof__(ptr) __xg_ptr = (ptr); \
73 __typeof__(*(ptr)) __xg_orig, __xg_tmp; \
74 __typeof__(*(ptr)) __xg_test = (test); \
75 __typeof__(*(ptr)) __xg_new = (new); \
76 \
77 switch (sizeof(__xg_orig)) { \
78 case 4: \
79 asm volatile( \
80 "0: \n" \
81 " orcc gr0,gr0,gr0,icc3 \n" \
82 " ckeq icc3,cc7 \n" \
83 " ld.p %M0,%1 \n" \
84 " orcr cc7,cc7,cc3 \n" \
85 " sub%I4cc %1,%4,%2,icc0 \n" \
86 " bne icc0,#0,1f \n" \
87 " cst.p %3,%M0 ,cc3,#1 \n" \
88 " corcc gr29,gr29,gr0 ,cc3,#1 \n" \
89 " beq icc3,#0,0b \n" \
90 "1: \n" \
91 : "+U"(*__xg_ptr), "=&r"(__xg_orig), "=&r"(__xg_tmp) \
92 : "r"(__xg_new), "NPr"(__xg_test) \
93 : "memory", "cc7", "cc3", "icc3", "icc0" \
94 ); \
95 break; \
96 \
97 default: \
98 __xg_orig = (__typeof__(__xg_orig))0; \
99 asm volatile("break"); \
100 break; \
101 } \
102 \
103 __xg_orig; \
104})
105
106#else
107
108extern uint32_t __cmpxchg_32(uint32_t *v, uint32_t test, uint32_t new);
109
110#define cmpxchg(ptr, test, new) \
111({ \
112 __typeof__(ptr) __xg_ptr = (ptr); \
113 __typeof__(*(ptr)) __xg_orig; \
114 __typeof__(*(ptr)) __xg_test = (test); \
115 __typeof__(*(ptr)) __xg_new = (new); \
116 \
117 switch (sizeof(__xg_orig)) { \
118 case 4: __xg_orig = (__force __typeof__(*ptr)) \
119 __cmpxchg_32((__force uint32_t *)__xg_ptr, \
120 (__force uint32_t)__xg_test, \
121 (__force uint32_t)__xg_new); break; \
122 default: \
123 __xg_orig = (__typeof__(__xg_orig))0; \
124 asm volatile("break"); \
125 break; \
126 } \
127 \
128 __xg_orig; \
129})
130
131#endif
132
133#include <asm-generic/cmpxchg-local.h>
134
135static inline unsigned long __cmpxchg_local(volatile void *ptr,
136 unsigned long old,
137 unsigned long new, int size)
138{
139 switch (size) {
140 case 4:
141 return cmpxchg((unsigned long *)ptr, old, new);
142 default:
143 return __cmpxchg_local_generic(ptr, old, new, size);
144 }
145
146 return old;
147}
148
149/*
150 * cmpxchg_local and cmpxchg64_local are atomic wrt current CPU. Always make
151 * them available.
152 */
153#define cmpxchg_local(ptr, o, n) \
154 ((__typeof__(*(ptr)))__cmpxchg_local((ptr), (unsigned long)(o), \
155 (unsigned long)(n), sizeof(*(ptr))))
156#define cmpxchg64_local(ptr, o, n) __cmpxchg64_local_generic((ptr), (o), (n))
157
158#endif /* _ASM_SYSTEM_H */