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 */
30 extern asmlinkage void *resume(void *last, void *next, void *next_ti);
31
32 struct 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) \
49 do { \
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) \
66 do { \
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 } while (0)
72
73 #define finish_arch_switch(prev) \
74 do { \
75 if (cpu_has_dsp) \
76 __restore_dsp(current); \
77 if (cpu_has_userlocal) \
78 write_c0_userlocal(current_thread_info()->tp_value); \
79 } while (0)
80
__xchg_u32(volatile int * m,unsigned int val)81 static inline unsigned long __xchg_u32(volatile int * m, unsigned int val)
82 {
83 __u32 retval;
84
85 if (cpu_has_llsc && R10000_LLSC_WAR) {
86 unsigned long dummy;
87
88 __asm__ __volatile__(
89 " .set mips3 \n"
90 "1: ll %0, %3 # xchg_u32 \n"
91 " .set mips0 \n"
92 " move %2, %z4 \n"
93 " .set mips3 \n"
94 " sc %2, %1 \n"
95 " beqzl %2, 1b \n"
96 " .set mips0 \n"
97 : "=&r" (retval), "=m" (*m), "=&r" (dummy)
98 : "R" (*m), "Jr" (val)
99 : "memory");
100 } else if (cpu_has_llsc) {
101 unsigned long dummy;
102
103 __asm__ __volatile__(
104 " .set mips3 \n"
105 "1: ll %0, %3 # xchg_u32 \n"
106 " .set mips0 \n"
107 " move %2, %z4 \n"
108 " .set mips3 \n"
109 " sc %2, %1 \n"
110 " beqz %2, 2f \n"
111 " .subsection 2 \n"
112 "2: b 1b \n"
113 " .previous \n"
114 " .set mips0 \n"
115 : "=&r" (retval), "=m" (*m), "=&r" (dummy)
116 : "R" (*m), "Jr" (val)
117 : "memory");
118 } else {
119 unsigned long flags;
120
121 raw_local_irq_save(flags);
122 retval = *m;
123 *m = val;
124 raw_local_irq_restore(flags); /* implies memory barrier */
125 }
126
127 smp_llsc_mb();
128
129 return retval;
130 }
131
132 #ifdef CONFIG_64BIT
__xchg_u64(volatile __u64 * m,__u64 val)133 static inline __u64 __xchg_u64(volatile __u64 * m, __u64 val)
134 {
135 __u64 retval;
136
137 if (cpu_has_llsc && R10000_LLSC_WAR) {
138 unsigned long dummy;
139
140 __asm__ __volatile__(
141 " .set mips3 \n"
142 "1: lld %0, %3 # xchg_u64 \n"
143 " move %2, %z4 \n"
144 " scd %2, %1 \n"
145 " beqzl %2, 1b \n"
146 " .set mips0 \n"
147 : "=&r" (retval), "=m" (*m), "=&r" (dummy)
148 : "R" (*m), "Jr" (val)
149 : "memory");
150 } else if (cpu_has_llsc) {
151 unsigned long dummy;
152
153 __asm__ __volatile__(
154 " .set mips3 \n"
155 "1: lld %0, %3 # xchg_u64 \n"
156 " move %2, %z4 \n"
157 " scd %2, %1 \n"
158 " beqz %2, 2f \n"
159 " .subsection 2 \n"
160 "2: b 1b \n"
161 " .previous \n"
162 " .set mips0 \n"
163 : "=&r" (retval), "=m" (*m), "=&r" (dummy)
164 : "R" (*m), "Jr" (val)
165 : "memory");
166 } else {
167 unsigned long flags;
168
169 raw_local_irq_save(flags);
170 retval = *m;
171 *m = val;
172 raw_local_irq_restore(flags); /* implies memory barrier */
173 }
174
175 smp_llsc_mb();
176
177 return retval;
178 }
179 #else
180 extern __u64 __xchg_u64_unsupported_on_32bit_kernels(volatile __u64 * m, __u64 val);
181 #define __xchg_u64 __xchg_u64_unsupported_on_32bit_kernels
182 #endif
183
184 /* This function doesn't exist, so you'll get a linker error
185 if something tries to do an invalid xchg(). */
186 extern void __xchg_called_with_bad_pointer(void);
187
__xchg(unsigned long x,volatile void * ptr,int size)188 static inline unsigned long __xchg(unsigned long x, volatile void * ptr, int size)
189 {
190 switch (size) {
191 case 4:
192 return __xchg_u32(ptr, x);
193 case 8:
194 return __xchg_u64(ptr, x);
195 }
196 __xchg_called_with_bad_pointer();
197 return x;
198 }
199
200 #define xchg(ptr, x) ((__typeof__(*(ptr)))__xchg((unsigned long)(x), (ptr), sizeof(*(ptr))))
201
202 extern void set_handler(unsigned long offset, void *addr, unsigned long len);
203 extern void set_uncached_handler(unsigned long offset, void *addr, unsigned long len);
204
205 typedef void (*vi_handler_t)(void);
206 extern void *set_vi_handler(int n, vi_handler_t addr);
207
208 extern void *set_except_vector(int n, void *addr);
209 extern unsigned long ebase;
210 extern void per_cpu_trap_init(void);
211
212 /*
213 * See include/asm-ia64/system.h; prevents deadlock on SMP
214 * systems.
215 */
216 #define __ARCH_WANT_UNLOCKED_CTXSW
217
218 extern unsigned long arch_align_stack(unsigned long sp);
219
220 #endif /* _ASM_SYSTEM_H */
221