xref: /openbmc/linux/arch/s390/include/asm/switch_to.h (revision afb46f79)
1 /*
2  * Copyright IBM Corp. 1999, 2009
3  *
4  * Author(s): Martin Schwidefsky <schwidefsky@de.ibm.com>
5  */
6 
7 #ifndef __ASM_SWITCH_TO_H
8 #define __ASM_SWITCH_TO_H
9 
10 #include <linux/thread_info.h>
11 #include <asm/ptrace.h>
12 
13 extern struct task_struct *__switch_to(void *, void *);
14 extern void update_cr_regs(struct task_struct *task);
15 
16 static inline int test_fp_ctl(u32 fpc)
17 {
18 	u32 orig_fpc;
19 	int rc;
20 
21 	if (!MACHINE_HAS_IEEE)
22 		return 0;
23 
24 	asm volatile(
25 		"	efpc    %1\n"
26 		"	sfpc	%2\n"
27 		"0:	sfpc	%1\n"
28 		"	la	%0,0\n"
29 		"1:\n"
30 		EX_TABLE(0b,1b)
31 		: "=d" (rc), "=d" (orig_fpc)
32 		: "d" (fpc), "0" (-EINVAL));
33 	return rc;
34 }
35 
36 static inline void save_fp_ctl(u32 *fpc)
37 {
38 	if (!MACHINE_HAS_IEEE)
39 		return;
40 
41 	asm volatile(
42 		"       stfpc   %0\n"
43 		: "+Q" (*fpc));
44 }
45 
46 static inline int restore_fp_ctl(u32 *fpc)
47 {
48 	int rc;
49 
50 	if (!MACHINE_HAS_IEEE)
51 		return 0;
52 
53 	asm volatile(
54 		"0:	lfpc    %1\n"
55 		"	la	%0,0\n"
56 		"1:\n"
57 		EX_TABLE(0b,1b)
58 		: "=d" (rc) : "Q" (*fpc), "0" (-EINVAL));
59 	return rc;
60 }
61 
62 static inline void save_fp_regs(freg_t *fprs)
63 {
64 	asm volatile("std 0,%0" : "=Q" (fprs[0]));
65 	asm volatile("std 2,%0" : "=Q" (fprs[2]));
66 	asm volatile("std 4,%0" : "=Q" (fprs[4]));
67 	asm volatile("std 6,%0" : "=Q" (fprs[6]));
68 	if (!MACHINE_HAS_IEEE)
69 		return;
70 	asm volatile("std 1,%0" : "=Q" (fprs[1]));
71 	asm volatile("std 3,%0" : "=Q" (fprs[3]));
72 	asm volatile("std 5,%0" : "=Q" (fprs[5]));
73 	asm volatile("std 7,%0" : "=Q" (fprs[7]));
74 	asm volatile("std 8,%0" : "=Q" (fprs[8]));
75 	asm volatile("std 9,%0" : "=Q" (fprs[9]));
76 	asm volatile("std 10,%0" : "=Q" (fprs[10]));
77 	asm volatile("std 11,%0" : "=Q" (fprs[11]));
78 	asm volatile("std 12,%0" : "=Q" (fprs[12]));
79 	asm volatile("std 13,%0" : "=Q" (fprs[13]));
80 	asm volatile("std 14,%0" : "=Q" (fprs[14]));
81 	asm volatile("std 15,%0" : "=Q" (fprs[15]));
82 }
83 
84 static inline void restore_fp_regs(freg_t *fprs)
85 {
86 	asm volatile("ld 0,%0" : : "Q" (fprs[0]));
87 	asm volatile("ld 2,%0" : : "Q" (fprs[2]));
88 	asm volatile("ld 4,%0" : : "Q" (fprs[4]));
89 	asm volatile("ld 6,%0" : : "Q" (fprs[6]));
90 	if (!MACHINE_HAS_IEEE)
91 		return;
92 	asm volatile("ld 1,%0" : : "Q" (fprs[1]));
93 	asm volatile("ld 3,%0" : : "Q" (fprs[3]));
94 	asm volatile("ld 5,%0" : : "Q" (fprs[5]));
95 	asm volatile("ld 7,%0" : : "Q" (fprs[7]));
96 	asm volatile("ld 8,%0" : : "Q" (fprs[8]));
97 	asm volatile("ld 9,%0" : : "Q" (fprs[9]));
98 	asm volatile("ld 10,%0" : : "Q" (fprs[10]));
99 	asm volatile("ld 11,%0" : : "Q" (fprs[11]));
100 	asm volatile("ld 12,%0" : : "Q" (fprs[12]));
101 	asm volatile("ld 13,%0" : : "Q" (fprs[13]));
102 	asm volatile("ld 14,%0" : : "Q" (fprs[14]));
103 	asm volatile("ld 15,%0" : : "Q" (fprs[15]));
104 }
105 
106 static inline void save_access_regs(unsigned int *acrs)
107 {
108 	typedef struct { int _[NUM_ACRS]; } acrstype;
109 
110 	asm volatile("stam 0,15,%0" : "=Q" (*(acrstype *)acrs));
111 }
112 
113 static inline void restore_access_regs(unsigned int *acrs)
114 {
115 	typedef struct { int _[NUM_ACRS]; } acrstype;
116 
117 	asm volatile("lam 0,15,%0" : : "Q" (*(acrstype *)acrs));
118 }
119 
120 #define switch_to(prev,next,last) do {					\
121 	if (prev->mm) {							\
122 		save_fp_ctl(&prev->thread.fp_regs.fpc);			\
123 		save_fp_regs(prev->thread.fp_regs.fprs);		\
124 		save_access_regs(&prev->thread.acrs[0]);		\
125 		save_ri_cb(prev->thread.ri_cb);				\
126 	}								\
127 	if (next->mm) {							\
128 		restore_fp_ctl(&next->thread.fp_regs.fpc);		\
129 		restore_fp_regs(next->thread.fp_regs.fprs);		\
130 		restore_access_regs(&next->thread.acrs[0]);		\
131 		restore_ri_cb(next->thread.ri_cb, prev->thread.ri_cb);	\
132 		update_cr_regs(next);					\
133 	}								\
134 	prev = __switch_to(prev,next);					\
135 	update_primary_asce(current);					\
136 } while (0)
137 
138 #define finish_arch_switch(prev) do {					     \
139 	set_fs(current->thread.mm_segment);				     \
140 } while (0)
141 
142 #endif /* __ASM_SWITCH_TO_H */
143