1 /*
2 * File: include/asm/system.h
3 * Based on:
4 * Author: Tony Kou (tonyko@lineo.ca)
5 * Copyright (c) 2002 Arcturus Networks Inc.
6 * (www.arcturusnetworks.com)
7 * Copyright (c) 2003 Metrowerks (www.metrowerks.com)
8 * Copyright (c) 2004 Analog Device Inc.
9 * Created: 25Jan2001 - Tony Kou
10 * Description: system.h include file
11 *
12 * Modified: 22Sep2006 - Robin Getz
13 * - move include blackfin.h down, so I can get access to
14 * irq functions in other include files.
15 *
16 * Bugs: Enter bugs at http://blackfin.uclinux.org/
17 *
18 * This program is free software; you can redistribute it and/or modify
19 * it under the terms of the GNU General Public License as published by
20 * the Free Software Foundation; either version 2, or (at your option)
21 * any later version.
22 *
23 * This program is distributed in the hope that it will be useful,
24 * but WITHOUT ANY WARRANTY; without even the implied warranty of
25 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
26 * GNU General Public License for more details.
27 *
28 * You should have received a copy of the GNU General Public License
29 * along with this program; see the file COPYING.
30 * If not, write to the Free Software Foundation,
31 * 59 Temple Place - Suite 330, Boston, MA 02111-1307, USA.
32 */
33
34 #ifndef _BLACKFIN_SYSTEM_H
35 #define _BLACKFIN_SYSTEM_H
36
37 #include <linux/linkage.h>
38 #include <linux/compiler.h>
39 #include <mach/anomaly.h>
40 #include <asm/pda.h>
41 #include <asm/processor.h>
42 #include <asm/irq.h>
43
44 /*
45 * Force strict CPU ordering.
46 */
47 #define nop() __asm__ __volatile__ ("nop;\n\t" : : )
48 #define mb() __asm__ __volatile__ ("" : : : "memory")
49 #define rmb() __asm__ __volatile__ ("" : : : "memory")
50 #define wmb() __asm__ __volatile__ ("" : : : "memory")
51 #define set_mb(var, value) do { (void) xchg(&var, value); } while (0)
52 #define read_barrier_depends() do { } while(0)
53
54 #ifdef CONFIG_SMP
55 asmlinkage unsigned long __raw_xchg_1_asm(volatile void *ptr, unsigned long value);
56 asmlinkage unsigned long __raw_xchg_2_asm(volatile void *ptr, unsigned long value);
57 asmlinkage unsigned long __raw_xchg_4_asm(volatile void *ptr, unsigned long value);
58 asmlinkage unsigned long __raw_cmpxchg_1_asm(volatile void *ptr,
59 unsigned long new, unsigned long old);
60 asmlinkage unsigned long __raw_cmpxchg_2_asm(volatile void *ptr,
61 unsigned long new, unsigned long old);
62 asmlinkage unsigned long __raw_cmpxchg_4_asm(volatile void *ptr,
63 unsigned long new, unsigned long old);
64
65 #ifdef __ARCH_SYNC_CORE_DCACHE
66 # define smp_mb() do { barrier(); smp_check_barrier(); smp_mark_barrier(); } while (0)
67 # define smp_rmb() do { barrier(); smp_check_barrier(); } while (0)
68 # define smp_wmb() do { barrier(); smp_mark_barrier(); } while (0)
69 #define smp_read_barrier_depends() do { barrier(); smp_check_barrier(); } while (0)
70
71 #else
72 # define smp_mb() barrier()
73 # define smp_rmb() barrier()
74 # define smp_wmb() barrier()
75 #define smp_read_barrier_depends() barrier()
76 #endif
77
__xchg(unsigned long x,volatile void * ptr,int size)78 static inline unsigned long __xchg(unsigned long x, volatile void *ptr,
79 int size)
80 {
81 unsigned long tmp;
82
83 switch (size) {
84 case 1:
85 tmp = __raw_xchg_1_asm(ptr, x);
86 break;
87 case 2:
88 tmp = __raw_xchg_2_asm(ptr, x);
89 break;
90 case 4:
91 tmp = __raw_xchg_4_asm(ptr, x);
92 break;
93 }
94
95 return tmp;
96 }
97
98 /*
99 * Atomic compare and exchange. Compare OLD with MEM, if identical,
100 * store NEW in MEM. Return the initial value in MEM. Success is
101 * indicated by comparing RETURN with OLD.
102 */
__cmpxchg(volatile void * ptr,unsigned long old,unsigned long new,int size)103 static inline unsigned long __cmpxchg(volatile void *ptr, unsigned long old,
104 unsigned long new, int size)
105 {
106 unsigned long tmp;
107
108 switch (size) {
109 case 1:
110 tmp = __raw_cmpxchg_1_asm(ptr, new, old);
111 break;
112 case 2:
113 tmp = __raw_cmpxchg_2_asm(ptr, new, old);
114 break;
115 case 4:
116 tmp = __raw_cmpxchg_4_asm(ptr, new, old);
117 break;
118 }
119
120 return tmp;
121 }
122 #define cmpxchg(ptr, o, n) \
123 ((__typeof__(*(ptr)))__cmpxchg((ptr), (unsigned long)(o), \
124 (unsigned long)(n), sizeof(*(ptr))))
125
126 #else /* !CONFIG_SMP */
127
128 #define smp_mb() barrier()
129 #define smp_rmb() barrier()
130 #define smp_wmb() barrier()
131 #define smp_read_barrier_depends() do { } while(0)
132
133 struct __xchg_dummy {
134 unsigned long a[100];
135 };
136 #define __xg(x) ((volatile struct __xchg_dummy *)(x))
137
__xchg(unsigned long x,volatile void * ptr,int size)138 static inline unsigned long __xchg(unsigned long x, volatile void *ptr,
139 int size)
140 {
141 unsigned long tmp = 0;
142 unsigned long flags = 0;
143
144 local_irq_save_hw(flags);
145
146 switch (size) {
147 case 1:
148 __asm__ __volatile__
149 ("%0 = b%2 (z);\n\t"
150 "b%2 = %1;\n\t"
151 : "=&d" (tmp) : "d" (x), "m" (*__xg(ptr)) : "memory");
152 break;
153 case 2:
154 __asm__ __volatile__
155 ("%0 = w%2 (z);\n\t"
156 "w%2 = %1;\n\t"
157 : "=&d" (tmp) : "d" (x), "m" (*__xg(ptr)) : "memory");
158 break;
159 case 4:
160 __asm__ __volatile__
161 ("%0 = %2;\n\t"
162 "%2 = %1;\n\t"
163 : "=&d" (tmp) : "d" (x), "m" (*__xg(ptr)) : "memory");
164 break;
165 }
166 local_irq_restore_hw(flags);
167 return tmp;
168 }
169
170 #include <asm-generic/cmpxchg-local.h>
171
172 /*
173 * cmpxchg_local and cmpxchg64_local are atomic wrt current CPU. Always make
174 * them available.
175 */
176 #define cmpxchg_local(ptr, o, n) \
177 ((__typeof__(*(ptr)))__cmpxchg_local_generic((ptr), (unsigned long)(o),\
178 (unsigned long)(n), sizeof(*(ptr))))
179 #define cmpxchg64_local(ptr, o, n) __cmpxchg64_local_generic((ptr), (o), (n))
180
181 #include <asm-generic/cmpxchg.h>
182
183 #endif /* !CONFIG_SMP */
184
185 #define xchg(ptr, x) ((__typeof__(*(ptr)))__xchg((unsigned long)(x), (ptr), sizeof(*(ptr))))
186 #define tas(ptr) ((void)xchg((ptr), 1))
187
188 #define prepare_to_switch() do { } while(0)
189
190 /*
191 * switch_to(n) should switch tasks to task ptr, first checking that
192 * ptr isn't the current task, in which case it does nothing.
193 */
194
195 #include <asm/l1layout.h>
196 #include <asm/mem_map.h>
197
198 asmlinkage struct task_struct *resume(struct task_struct *prev, struct task_struct *next);
199
200 #ifndef CONFIG_SMP
201 #define switch_to(prev,next,last) \
202 do { \
203 memcpy (&task_thread_info(prev)->l1_task_info, L1_SCRATCH_TASK_INFO, \
204 sizeof *L1_SCRATCH_TASK_INFO); \
205 memcpy (L1_SCRATCH_TASK_INFO, &task_thread_info(next)->l1_task_info, \
206 sizeof *L1_SCRATCH_TASK_INFO); \
207 (last) = resume (prev, next); \
208 } while (0)
209 #else
210 #define switch_to(prev, next, last) \
211 do { \
212 (last) = resume(prev, next); \
213 } while (0)
214 #endif
215
216 #endif /* _BLACKFIN_SYSTEM_H */
217