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/watch.h>
24 #include <asm/war.h>
25
26
27 /*
28 * switch_to(n) should switch tasks to task nr n, first
29 * checking that n isn't the current task, in which case it does nothing.
30 */
31 extern asmlinkage void *resume(void *last, void *next, void *next_ti);
32
33 struct task_struct;
34
35 #ifdef CONFIG_MIPS_MT_FPAFF
36
37 /*
38 * Handle the scheduler resume end of FPU affinity management. We do this
39 * inline to try to keep the overhead down. If we have been forced to run on
40 * a "CPU" with an FPU because of a previous high level of FP computation,
41 * but did not actually use the FPU during the most recent time-slice (CU1
42 * isn't set), we undo the restriction on cpus_allowed.
43 *
44 * We're not calling set_cpus_allowed() here, because we have no need to
45 * force prompt migration - we're already switching the current CPU to a
46 * different thread.
47 */
48
49 #define __mips_mt_fpaff_switch_to(prev) \
50 do { \
51 struct thread_info *__prev_ti = task_thread_info(prev); \
52 \
53 if (cpu_has_fpu && \
54 test_ti_thread_flag(__prev_ti, TIF_FPUBOUND) && \
55 (!(KSTK_STATUS(prev) & ST0_CU1))) { \
56 clear_ti_thread_flag(__prev_ti, TIF_FPUBOUND); \
57 prev->cpus_allowed = prev->thread.user_cpus_allowed; \
58 } \
59 next->thread.emulated_fp = 0; \
60 } while(0)
61
62 #else
63 #define __mips_mt_fpaff_switch_to(prev) do { (void) (prev); } while (0)
64 #endif
65
66 #define switch_to(prev, next, last) \
67 do { \
68 __mips_mt_fpaff_switch_to(prev); \
69 if (cpu_has_dsp) \
70 __save_dsp(prev); \
71 (last) = resume(prev, next, task_thread_info(next)); \
72 } while (0)
73
74 #define finish_arch_switch(prev) \
75 do { \
76 if (cpu_has_dsp) \
77 __restore_dsp(current); \
78 if (cpu_has_userlocal) \
79 write_c0_userlocal(current_thread_info()->tp_value); \
80 __restore_watch(); \
81 } while (0)
82
__xchg_u32(volatile int * m,unsigned int val)83 static inline unsigned long __xchg_u32(volatile int * m, unsigned int val)
84 {
85 __u32 retval;
86
87 if (cpu_has_llsc && R10000_LLSC_WAR) {
88 unsigned long dummy;
89
90 __asm__ __volatile__(
91 " .set mips3 \n"
92 "1: ll %0, %3 # xchg_u32 \n"
93 " .set mips0 \n"
94 " move %2, %z4 \n"
95 " .set mips3 \n"
96 " sc %2, %1 \n"
97 " beqzl %2, 1b \n"
98 " .set mips0 \n"
99 : "=&r" (retval), "=m" (*m), "=&r" (dummy)
100 : "R" (*m), "Jr" (val)
101 : "memory");
102 } else if (cpu_has_llsc) {
103 unsigned long dummy;
104
105 __asm__ __volatile__(
106 " .set mips3 \n"
107 "1: ll %0, %3 # xchg_u32 \n"
108 " .set mips0 \n"
109 " move %2, %z4 \n"
110 " .set mips3 \n"
111 " sc %2, %1 \n"
112 " beqz %2, 2f \n"
113 " .subsection 2 \n"
114 "2: b 1b \n"
115 " .previous \n"
116 " .set mips0 \n"
117 : "=&r" (retval), "=m" (*m), "=&r" (dummy)
118 : "R" (*m), "Jr" (val)
119 : "memory");
120 } else {
121 unsigned long flags;
122
123 raw_local_irq_save(flags);
124 retval = *m;
125 *m = val;
126 raw_local_irq_restore(flags); /* implies memory barrier */
127 }
128
129 smp_llsc_mb();
130
131 return retval;
132 }
133
134 #ifdef CONFIG_64BIT
__xchg_u64(volatile __u64 * m,__u64 val)135 static inline __u64 __xchg_u64(volatile __u64 * m, __u64 val)
136 {
137 __u64 retval;
138
139 if (cpu_has_llsc && R10000_LLSC_WAR) {
140 unsigned long dummy;
141
142 __asm__ __volatile__(
143 " .set mips3 \n"
144 "1: lld %0, %3 # xchg_u64 \n"
145 " move %2, %z4 \n"
146 " scd %2, %1 \n"
147 " beqzl %2, 1b \n"
148 " .set mips0 \n"
149 : "=&r" (retval), "=m" (*m), "=&r" (dummy)
150 : "R" (*m), "Jr" (val)
151 : "memory");
152 } else if (cpu_has_llsc) {
153 unsigned long dummy;
154
155 __asm__ __volatile__(
156 " .set mips3 \n"
157 "1: lld %0, %3 # xchg_u64 \n"
158 " move %2, %z4 \n"
159 " scd %2, %1 \n"
160 " beqz %2, 2f \n"
161 " .subsection 2 \n"
162 "2: b 1b \n"
163 " .previous \n"
164 " .set mips0 \n"
165 : "=&r" (retval), "=m" (*m), "=&r" (dummy)
166 : "R" (*m), "Jr" (val)
167 : "memory");
168 } else {
169 unsigned long flags;
170
171 raw_local_irq_save(flags);
172 retval = *m;
173 *m = val;
174 raw_local_irq_restore(flags); /* implies memory barrier */
175 }
176
177 smp_llsc_mb();
178
179 return retval;
180 }
181 #else
182 extern __u64 __xchg_u64_unsupported_on_32bit_kernels(volatile __u64 * m, __u64 val);
183 #define __xchg_u64 __xchg_u64_unsupported_on_32bit_kernels
184 #endif
185
186 /* This function doesn't exist, so you'll get a linker error
187 if something tries to do an invalid xchg(). */
188 extern void __xchg_called_with_bad_pointer(void);
189
__xchg(unsigned long x,volatile void * ptr,int size)190 static inline unsigned long __xchg(unsigned long x, volatile void * ptr, int size)
191 {
192 switch (size) {
193 case 4:
194 return __xchg_u32(ptr, x);
195 case 8:
196 return __xchg_u64(ptr, x);
197 }
198 __xchg_called_with_bad_pointer();
199 return x;
200 }
201
202 #define xchg(ptr, x) ((__typeof__(*(ptr)))__xchg((unsigned long)(x), (ptr), sizeof(*(ptr))))
203
204 extern void set_handler(unsigned long offset, void *addr, unsigned long len);
205 extern void set_uncached_handler(unsigned long offset, void *addr, unsigned long len);
206
207 typedef void (*vi_handler_t)(void);
208 extern void *set_vi_handler(int n, vi_handler_t addr);
209
210 extern void *set_except_vector(int n, void *addr);
211 extern unsigned long ebase;
212 extern void per_cpu_trap_init(void);
213
214 /*
215 * See include/asm-ia64/system.h; prevents deadlock on SMP
216 * systems.
217 */
218 #define __ARCH_WANT_UNLOCKED_CTXSW
219
220 extern unsigned long arch_align_stack(unsigned long sp);
221
222 #endif /* _ASM_SYSTEM_H */
223