xref: /openbmc/linux/arch/s390/include/asm/switch_to.h (revision e2f1cf25)
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 	asm volatile(
22 		"	efpc    %1\n"
23 		"	sfpc	%2\n"
24 		"0:	sfpc	%1\n"
25 		"	la	%0,0\n"
26 		"1:\n"
27 		EX_TABLE(0b,1b)
28 		: "=d" (rc), "=d" (orig_fpc)
29 		: "d" (fpc), "0" (-EINVAL));
30 	return rc;
31 }
32 
33 static inline void save_fp_ctl(u32 *fpc)
34 {
35 	asm volatile(
36 		"       stfpc   %0\n"
37 		: "+Q" (*fpc));
38 }
39 
40 static inline int restore_fp_ctl(u32 *fpc)
41 {
42 	int rc;
43 
44 	asm volatile(
45 		"	lfpc    %1\n"
46 		"0:	la	%0,0\n"
47 		"1:\n"
48 		EX_TABLE(0b,1b)
49 		: "=d" (rc) : "Q" (*fpc), "0" (-EINVAL));
50 	return rc;
51 }
52 
53 static inline void save_fp_regs(freg_t *fprs)
54 {
55 	asm volatile("std 0,%0" : "=Q" (fprs[0]));
56 	asm volatile("std 2,%0" : "=Q" (fprs[2]));
57 	asm volatile("std 4,%0" : "=Q" (fprs[4]));
58 	asm volatile("std 6,%0" : "=Q" (fprs[6]));
59 	asm volatile("std 1,%0" : "=Q" (fprs[1]));
60 	asm volatile("std 3,%0" : "=Q" (fprs[3]));
61 	asm volatile("std 5,%0" : "=Q" (fprs[5]));
62 	asm volatile("std 7,%0" : "=Q" (fprs[7]));
63 	asm volatile("std 8,%0" : "=Q" (fprs[8]));
64 	asm volatile("std 9,%0" : "=Q" (fprs[9]));
65 	asm volatile("std 10,%0" : "=Q" (fprs[10]));
66 	asm volatile("std 11,%0" : "=Q" (fprs[11]));
67 	asm volatile("std 12,%0" : "=Q" (fprs[12]));
68 	asm volatile("std 13,%0" : "=Q" (fprs[13]));
69 	asm volatile("std 14,%0" : "=Q" (fprs[14]));
70 	asm volatile("std 15,%0" : "=Q" (fprs[15]));
71 }
72 
73 static inline void restore_fp_regs(freg_t *fprs)
74 {
75 	asm volatile("ld 0,%0" : : "Q" (fprs[0]));
76 	asm volatile("ld 2,%0" : : "Q" (fprs[2]));
77 	asm volatile("ld 4,%0" : : "Q" (fprs[4]));
78 	asm volatile("ld 6,%0" : : "Q" (fprs[6]));
79 	asm volatile("ld 1,%0" : : "Q" (fprs[1]));
80 	asm volatile("ld 3,%0" : : "Q" (fprs[3]));
81 	asm volatile("ld 5,%0" : : "Q" (fprs[5]));
82 	asm volatile("ld 7,%0" : : "Q" (fprs[7]));
83 	asm volatile("ld 8,%0" : : "Q" (fprs[8]));
84 	asm volatile("ld 9,%0" : : "Q" (fprs[9]));
85 	asm volatile("ld 10,%0" : : "Q" (fprs[10]));
86 	asm volatile("ld 11,%0" : : "Q" (fprs[11]));
87 	asm volatile("ld 12,%0" : : "Q" (fprs[12]));
88 	asm volatile("ld 13,%0" : : "Q" (fprs[13]));
89 	asm volatile("ld 14,%0" : : "Q" (fprs[14]));
90 	asm volatile("ld 15,%0" : : "Q" (fprs[15]));
91 }
92 
93 static inline void save_vx_regs(__vector128 *vxrs)
94 {
95 	typedef struct { __vector128 _[__NUM_VXRS]; } addrtype;
96 
97 	asm volatile(
98 		"	la	1,%0\n"
99 		"	.word	0xe70f,0x1000,0x003e\n"	/* vstm 0,15,0(1) */
100 		"	.word	0xe70f,0x1100,0x0c3e\n"	/* vstm 16,31,256(1) */
101 		: "=Q" (*(addrtype *) vxrs) : : "1");
102 }
103 
104 static inline void save_vx_regs_safe(__vector128 *vxrs)
105 {
106 	unsigned long cr0, flags;
107 
108 	flags = arch_local_irq_save();
109 	__ctl_store(cr0, 0, 0);
110 	__ctl_set_bit(0, 17);
111 	__ctl_set_bit(0, 18);
112 	save_vx_regs(vxrs);
113 	__ctl_load(cr0, 0, 0);
114 	arch_local_irq_restore(flags);
115 }
116 
117 static inline void restore_vx_regs(__vector128 *vxrs)
118 {
119 	typedef struct { __vector128 _[__NUM_VXRS]; } addrtype;
120 
121 	asm volatile(
122 		"	la	1,%0\n"
123 		"	.word	0xe70f,0x1000,0x0036\n"	/* vlm 0,15,0(1) */
124 		"	.word	0xe70f,0x1100,0x0c36\n"	/* vlm 16,31,256(1) */
125 		: : "Q" (*(addrtype *) vxrs) : "1");
126 }
127 
128 static inline void save_fp_vx_regs(struct task_struct *task)
129 {
130 	if (task->thread.vxrs)
131 		save_vx_regs(task->thread.vxrs);
132 	else
133 		save_fp_regs(task->thread.fp_regs.fprs);
134 }
135 
136 static inline void restore_fp_vx_regs(struct task_struct *task)
137 {
138 	if (task->thread.vxrs)
139 		restore_vx_regs(task->thread.vxrs);
140 	else
141 		restore_fp_regs(task->thread.fp_regs.fprs);
142 }
143 
144 static inline void save_access_regs(unsigned int *acrs)
145 {
146 	typedef struct { int _[NUM_ACRS]; } acrstype;
147 
148 	asm volatile("stam 0,15,%0" : "=Q" (*(acrstype *)acrs));
149 }
150 
151 static inline void restore_access_regs(unsigned int *acrs)
152 {
153 	typedef struct { int _[NUM_ACRS]; } acrstype;
154 
155 	asm volatile("lam 0,15,%0" : : "Q" (*(acrstype *)acrs));
156 }
157 
158 #define switch_to(prev,next,last) do {					\
159 	if (prev->mm) {							\
160 		save_fp_ctl(&prev->thread.fp_regs.fpc);			\
161 		save_fp_vx_regs(prev);					\
162 		save_access_regs(&prev->thread.acrs[0]);		\
163 		save_ri_cb(prev->thread.ri_cb);				\
164 	}								\
165 	if (next->mm) {							\
166 		update_cr_regs(next);					\
167 		restore_fp_ctl(&next->thread.fp_regs.fpc);		\
168 		restore_fp_vx_regs(next);				\
169 		restore_access_regs(&next->thread.acrs[0]);		\
170 		restore_ri_cb(next->thread.ri_cb, prev->thread.ri_cb);	\
171 	}								\
172 	prev = __switch_to(prev,next);					\
173 } while (0)
174 
175 #endif /* __ASM_SWITCH_TO_H */
176