5e5f1a0566c0fe6b1c90d9d0d0b039ed23c289e8
[linux-2.6.git] / include / asm-blackfin / system.h
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
40 /*
41  * Interrupt configuring macros.
42  */
43
44 extern unsigned long irq_flags;
45
46 #define local_irq_enable() do {         \
47         __asm__ __volatile__ (          \
48                 "sti %0;"               \
49                 ::"d"(irq_flags));      \
50 } while (0)
51
52 #define local_irq_disable() do {        \
53         int _tmp_dummy;                 \
54         __asm__ __volatile__ (          \
55                 "cli %0;"               \
56                 :"=d" (_tmp_dummy):);   \
57 } while (0)
58
59 #if defined(ANOMALY_05000244) && defined (CONFIG_BLKFIN_CACHE)
60 #define idle_with_irq_disabled() do {   \
61         __asm__ __volatile__ (          \
62                 "nop; nop;\n"           \
63                 ".align 8;\n"           \
64                 "sti %0; idle;\n"       \
65                 ::"d" (irq_flags));     \
66 } while (0)
67 #else
68 #define idle_with_irq_disabled() do {   \
69         __asm__ __volatile__ (          \
70                 ".align 8;\n"           \
71                 "sti %0; idle;\n"       \
72                 ::"d" (irq_flags));     \
73 } while (0)
74 #endif
75
76 #ifdef CONFIG_DEBUG_HWERR
77 #define __save_and_cli(x) do {                  \
78         __asm__ __volatile__ (                  \
79                 "cli %0;\n\tsti %1;"            \
80                 :"=&d"(x): "d" (0x3F));         \
81 } while (0)
82 #else
83 #define __save_and_cli(x) do {          \
84         __asm__ __volatile__ (          \
85                 "cli %0;"               \
86                 :"=&d"(x):);            \
87 } while (0)
88 #endif
89
90 #define local_save_flags(x) asm volatile ("cli %0;"     \
91                                           "sti %0;"     \
92                                           :"=d"(x):);
93
94 #ifdef CONFIG_DEBUG_HWERR
95 #define irqs_enabled_from_flags(x) (((x) & ~0x3f) != 0)
96 #else
97 #define irqs_enabled_from_flags(x) ((x) != 0x1f)
98 #endif
99
100 #define local_irq_restore(x) do {                       \
101         if (irqs_enabled_from_flags(x))                 \
102                 local_irq_enable ();                    \
103 } while (0)
104
105 /* For spinlocks etc */
106 #define local_irq_save(x) __save_and_cli(x)
107
108 #define irqs_disabled()                         \
109 ({                                              \
110         unsigned long flags;                    \
111         local_save_flags(flags);                \
112         !irqs_enabled_from_flags(flags);        \
113 })
114
115 /*
116  * Force strict CPU ordering.
117  */
118 #define nop()  asm volatile ("nop;\n\t"::)
119 #define mb()   asm volatile (""   : : :"memory")
120 #define rmb()  asm volatile (""   : : :"memory")
121 #define wmb()  asm volatile (""   : : :"memory")
122 #define set_rmb(var, value)    do { (void) xchg(&var, value); } while (0)
123 #define set_mb(var, value)     set_rmb(var, value)
124 #define set_wmb(var, value)    do { var = value; wmb(); } while (0)
125
126 #define read_barrier_depends()          do { } while(0)
127
128 #ifdef CONFIG_SMP
129 #define smp_mb()        mb()
130 #define smp_rmb()       rmb()
131 #define smp_wmb()       wmb()
132 #define smp_read_barrier_depends()      read_barrier_depends()
133 #else
134 #define smp_mb()        barrier()
135 #define smp_rmb()       barrier()
136 #define smp_wmb()       barrier()
137 #define smp_read_barrier_depends()      do { } while(0)
138 #endif
139
140 #define xchg(ptr,x) ((__typeof__(*(ptr)))__xchg((unsigned long)(x),(ptr),sizeof(*(ptr))))
141
142 struct __xchg_dummy {
143         unsigned long a[100];
144 };
145 #define __xg(x) ((volatile struct __xchg_dummy *)(x))
146
147 static inline unsigned long __xchg(unsigned long x, volatile void *ptr,
148                                    int size)
149 {
150         unsigned long tmp = 0;
151         unsigned long flags = 0;
152
153         local_irq_save(flags);
154
155         switch (size) {
156         case 1:
157                 __asm__ __volatile__
158                         ("%0 = b%2 (z);\n\t"
159                          "b%2 = %1;\n\t"
160                          : "=&d" (tmp) : "d" (x), "m" (*__xg(ptr)) : "memory");
161                 break;
162         case 2:
163                 __asm__ __volatile__
164                         ("%0 = w%2 (z);\n\t"
165                          "w%2 = %1;\n\t"
166                          : "=&d" (tmp) : "d" (x), "m" (*__xg(ptr)) : "memory");
167                 break;
168         case 4:
169                 __asm__ __volatile__
170                         ("%0 = %2;\n\t"
171                          "%2 = %1;\n\t"
172                          : "=&d" (tmp) : "d" (x), "m" (*__xg(ptr)) : "memory");
173                 break;
174         }
175         local_irq_restore(flags);
176         return tmp;
177 }
178
179 /*
180  * Atomic compare and exchange.  Compare OLD with MEM, if identical,
181  * store NEW in MEM.  Return the initial value in MEM.  Success is
182  * indicated by comparing RETURN with OLD.
183  */
184 static inline unsigned long __cmpxchg(volatile void *ptr, unsigned long old,
185                                       unsigned long new, int size)
186 {
187         unsigned long tmp = 0;
188         unsigned long flags = 0;
189
190         local_irq_save(flags);
191
192         switch (size) {
193         case 1:
194                 __asm__ __volatile__
195                         ("%0 = b%3 (z);\n\t"
196                          "CC = %1 == %0;\n\t"
197                          "IF !CC JUMP 1f;\n\t"
198                          "b%3 = %2;\n\t"
199                          "1:\n\t"
200                          : "=&d" (tmp) : "d" (old), "d" (new), "m" (*__xg(ptr)) : "memory");
201                 break;
202         case 2:
203                 __asm__ __volatile__
204                         ("%0 = w%3 (z);\n\t"
205                          "CC = %1 == %0;\n\t"
206                          "IF !CC JUMP 1f;\n\t"
207                          "w%3 = %2;\n\t"
208                          "1:\n\t"
209                          : "=&d" (tmp) : "d" (old), "d" (new), "m" (*__xg(ptr)) : "memory");
210                 break;
211         case 4:
212                 __asm__ __volatile__
213                         ("%0 = %3;\n\t"
214                          "CC = %1 == %0;\n\t"
215                          "IF !CC JUMP 1f;\n\t"
216                          "%3 = %2;\n\t"
217                          "1:\n\t"
218                          : "=&d" (tmp) : "d" (old), "d" (new), "m" (*__xg(ptr)) : "memory");
219                 break;
220         }
221         local_irq_restore(flags);
222         return tmp;
223 }
224
225 #define cmpxchg(ptr,o,n)\
226         ((__typeof__(*(ptr)))__cmpxchg((ptr),(unsigned long)(o),\
227                                         (unsigned long)(n),sizeof(*(ptr))))
228
229 #define prepare_to_switch()     do { } while(0)
230
231 /*
232  * switch_to(n) should switch tasks to task ptr, first checking that
233  * ptr isn't the current task, in which case it does nothing.
234  */
235
236 #include <asm/blackfin.h>
237
238 asmlinkage struct task_struct *resume(struct task_struct *prev, struct task_struct *next);
239
240 #define switch_to(prev,next,last) \
241 do {    \
242         memcpy (&task_thread_info(prev)->l1_task_info, L1_SCRATCH_TASK_INFO, \
243                 sizeof *L1_SCRATCH_TASK_INFO); \
244         memcpy (L1_SCRATCH_TASK_INFO, &task_thread_info(next)->l1_task_info, \
245                 sizeof *L1_SCRATCH_TASK_INFO); \
246         (last) = resume (prev, next);   \
247 } while (0)
248
249 #endif                          /* _BLACKFIN_SYSTEM_H */