Linux kernel mirror (for testing)
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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) 1994, 95, 96, 97, 98, 99, 2003, 06 by Ralf Baechle
7 * Copyright (C) 1996 by Paul M. Antoine
8 * Copyright (C) 1999 Silicon Graphics
9 * Kevin D. Kissell, kevink@mips.org and Carsten Langgaard, carstenl@mips.com
10 * Copyright (C) 2000 MIPS Technologies, Inc.
11 */
12#ifndef _ASM_SYSTEM_H
13#define _ASM_SYSTEM_H
14
15#include <linux/types.h>
16#include <linux/irqflags.h>
17
18#include <asm/addrspace.h>
19#include <asm/barrier.h>
20#include <asm/cmpxchg.h>
21#include <asm/cpu-features.h>
22#include <asm/dsp.h>
23#include <asm/war.h>
24
25
26/*
27 * switch_to(n) should switch tasks to task nr n, first
28 * checking that n isn't the current task, in which case it does nothing.
29 */
30extern asmlinkage void *resume(void *last, void *next, void *next_ti);
31
32struct task_struct;
33
34#ifdef CONFIG_MIPS_MT_FPAFF
35
36/*
37 * Handle the scheduler resume end of FPU affinity management. We do this
38 * inline to try to keep the overhead down. If we have been forced to run on
39 * a "CPU" with an FPU because of a previous high level of FP computation,
40 * but did not actually use the FPU during the most recent time-slice (CU1
41 * isn't set), we undo the restriction on cpus_allowed.
42 *
43 * We're not calling set_cpus_allowed() here, because we have no need to
44 * force prompt migration - we're already switching the current CPU to a
45 * different thread.
46 */
47
48#define __mips_mt_fpaff_switch_to(prev) \
49do { \
50 struct thread_info *__prev_ti = task_thread_info(prev); \
51 \
52 if (cpu_has_fpu && \
53 test_ti_thread_flag(__prev_ti, TIF_FPUBOUND) && \
54 (!(KSTK_STATUS(prev) & ST0_CU1))) { \
55 clear_ti_thread_flag(__prev_ti, TIF_FPUBOUND); \
56 prev->cpus_allowed = prev->thread.user_cpus_allowed; \
57 } \
58 next->thread.emulated_fp = 0; \
59} while(0)
60
61#else
62#define __mips_mt_fpaff_switch_to(prev) do { (void) (prev); } while (0)
63#endif
64
65#define switch_to(prev, next, last) \
66do { \
67 __mips_mt_fpaff_switch_to(prev); \
68 if (cpu_has_dsp) \
69 __save_dsp(prev); \
70 (last) = resume(prev, next, task_thread_info(next)); \
71 if (cpu_has_dsp) \
72 __restore_dsp(current); \
73 if (cpu_has_userlocal) \
74 write_c0_userlocal(task_thread_info(current)->tp_value);\
75} while(0)
76
77static inline unsigned long __xchg_u32(volatile int * m, unsigned int val)
78{
79 __u32 retval;
80
81 if (cpu_has_llsc && R10000_LLSC_WAR) {
82 unsigned long dummy;
83
84 __asm__ __volatile__(
85 " .set mips3 \n"
86 "1: ll %0, %3 # xchg_u32 \n"
87 " .set mips0 \n"
88 " move %2, %z4 \n"
89 " .set mips3 \n"
90 " sc %2, %1 \n"
91 " beqzl %2, 1b \n"
92 " .set mips0 \n"
93 : "=&r" (retval), "=m" (*m), "=&r" (dummy)
94 : "R" (*m), "Jr" (val)
95 : "memory");
96 } else if (cpu_has_llsc) {
97 unsigned long dummy;
98
99 __asm__ __volatile__(
100 " .set mips3 \n"
101 "1: ll %0, %3 # xchg_u32 \n"
102 " .set mips0 \n"
103 " move %2, %z4 \n"
104 " .set mips3 \n"
105 " sc %2, %1 \n"
106 " beqz %2, 2f \n"
107 " .subsection 2 \n"
108 "2: b 1b \n"
109 " .previous \n"
110 " .set mips0 \n"
111 : "=&r" (retval), "=m" (*m), "=&r" (dummy)
112 : "R" (*m), "Jr" (val)
113 : "memory");
114 } else {
115 unsigned long flags;
116
117 raw_local_irq_save(flags);
118 retval = *m;
119 *m = val;
120 raw_local_irq_restore(flags); /* implies memory barrier */
121 }
122
123 smp_llsc_mb();
124
125 return retval;
126}
127
128#ifdef CONFIG_64BIT
129static inline __u64 __xchg_u64(volatile __u64 * m, __u64 val)
130{
131 __u64 retval;
132
133 if (cpu_has_llsc && R10000_LLSC_WAR) {
134 unsigned long dummy;
135
136 __asm__ __volatile__(
137 " .set mips3 \n"
138 "1: lld %0, %3 # xchg_u64 \n"
139 " move %2, %z4 \n"
140 " scd %2, %1 \n"
141 " beqzl %2, 1b \n"
142 " .set mips0 \n"
143 : "=&r" (retval), "=m" (*m), "=&r" (dummy)
144 : "R" (*m), "Jr" (val)
145 : "memory");
146 } else if (cpu_has_llsc) {
147 unsigned long dummy;
148
149 __asm__ __volatile__(
150 " .set mips3 \n"
151 "1: lld %0, %3 # xchg_u64 \n"
152 " move %2, %z4 \n"
153 " scd %2, %1 \n"
154 " beqz %2, 2f \n"
155 " .subsection 2 \n"
156 "2: b 1b \n"
157 " .previous \n"
158 " .set mips0 \n"
159 : "=&r" (retval), "=m" (*m), "=&r" (dummy)
160 : "R" (*m), "Jr" (val)
161 : "memory");
162 } else {
163 unsigned long flags;
164
165 raw_local_irq_save(flags);
166 retval = *m;
167 *m = val;
168 raw_local_irq_restore(flags); /* implies memory barrier */
169 }
170
171 smp_llsc_mb();
172
173 return retval;
174}
175#else
176extern __u64 __xchg_u64_unsupported_on_32bit_kernels(volatile __u64 * m, __u64 val);
177#define __xchg_u64 __xchg_u64_unsupported_on_32bit_kernels
178#endif
179
180/* This function doesn't exist, so you'll get a linker error
181 if something tries to do an invalid xchg(). */
182extern void __xchg_called_with_bad_pointer(void);
183
184static inline unsigned long __xchg(unsigned long x, volatile void * ptr, int size)
185{
186 switch (size) {
187 case 4:
188 return __xchg_u32(ptr, x);
189 case 8:
190 return __xchg_u64(ptr, x);
191 }
192 __xchg_called_with_bad_pointer();
193 return x;
194}
195
196#define xchg(ptr, x) ((__typeof__(*(ptr)))__xchg((unsigned long)(x), (ptr), sizeof(*(ptr))))
197
198extern void set_handler(unsigned long offset, void *addr, unsigned long len);
199extern void set_uncached_handler(unsigned long offset, void *addr, unsigned long len);
200
201typedef void (*vi_handler_t)(void);
202extern void *set_vi_handler(int n, vi_handler_t addr);
203
204extern void *set_except_vector(int n, void *addr);
205extern unsigned long ebase;
206extern void per_cpu_trap_init(void);
207
208extern int stop_a_enabled;
209
210/*
211 * See include/asm-ia64/system.h; prevents deadlock on SMP
212 * systems.
213 */
214#define __ARCH_WANT_UNLOCKED_CTXSW
215
216extern unsigned long arch_align_stack(unsigned long sp);
217
218#endif /* _ASM_SYSTEM_H */