xref: /linux/arch/sh/include/asm/syscall_32.h (revision 367b8112fe2ea5c39a7bb4d263dcdd9b612fae18)
1 #ifndef __ASM_SH_SYSCALL_32_H
2 #define __ASM_SH_SYSCALL_32_H
3 
4 #include <linux/kernel.h>
5 #include <linux/sched.h>
6 #include <asm/ptrace.h>
7 
8 /* The system call number is given by the user in %g1 */
9 static inline long syscall_get_nr(struct task_struct *task,
10 				  struct pt_regs *regs)
11 {
12 	return (regs->tra >= 0) ? regs->regs[3] : -1L;
13 }
14 
15 static inline void syscall_rollback(struct task_struct *task,
16 				    struct pt_regs *regs)
17 {
18 	/*
19 	 * XXX: This needs some thought. On SH we don't
20 	 * save away the original r0 value anywhere.
21 	 */
22 }
23 
24 static inline bool syscall_has_error(struct pt_regs *regs)
25 {
26 	return (regs->sr & 0x1) ? true : false;
27 }
28 static inline void syscall_set_error(struct pt_regs *regs)
29 {
30 	regs->sr |= 0x1;
31 }
32 static inline void syscall_clear_error(struct pt_regs *regs)
33 {
34 	regs->sr &= ~0x1;
35 }
36 
37 static inline long syscall_get_error(struct task_struct *task,
38 				     struct pt_regs *regs)
39 {
40 	return syscall_has_error(regs) ? regs->regs[0] : 0;
41 }
42 
43 static inline long syscall_get_return_value(struct task_struct *task,
44 					    struct pt_regs *regs)
45 {
46 	return regs->regs[0];
47 }
48 
49 static inline void syscall_set_return_value(struct task_struct *task,
50 					    struct pt_regs *regs,
51 					    int error, long val)
52 {
53 	if (error) {
54 		syscall_set_error(regs);
55 		regs->regs[0] = -error;
56 	} else {
57 		syscall_clear_error(regs);
58 		regs->regs[0] = val;
59 	}
60 }
61 
62 static inline void syscall_get_arguments(struct task_struct *task,
63 					 struct pt_regs *regs,
64 					 unsigned int i, unsigned int n,
65 					 unsigned long *args)
66 {
67 	/*
68 	 * Do this simply for now. If we need to start supporting
69 	 * fetching arguments from arbitrary indices, this will need some
70 	 * extra logic. Presently there are no in-tree users that depend
71 	 * on this behaviour.
72 	 */
73 	BUG_ON(i);
74 
75 	/* Argument pattern is: R4, R5, R6, R7, R0, R1 */
76 	switch (n) {
77 	case 6: args[5] = regs->regs[1];
78 	case 5: args[4] = regs->regs[0];
79 	case 4: args[3] = regs->regs[7];
80 	case 3: args[2] = regs->regs[6];
81 	case 2: args[1] = regs->regs[5];
82 	case 1:	args[0] = regs->regs[4];
83 		break;
84 	default:
85 		BUG();
86 	}
87 }
88 
89 static inline void syscall_set_arguments(struct task_struct *task,
90 					 struct pt_regs *regs,
91 					 unsigned int i, unsigned int n,
92 					 const unsigned long *args)
93 {
94 	/* Same note as above applies */
95 	BUG_ON(i);
96 
97 	switch (n) {
98 	case 6: regs->regs[1] = args[5];
99 	case 5: regs->regs[0] = args[4];
100 	case 4: regs->regs[7] = args[3];
101 	case 3: regs->regs[6] = args[2];
102 	case 2: regs->regs[5] = args[1];
103 	case 1: regs->regs[4] = args[0];
104 		break;
105 	default:
106 		BUG();
107 	}
108 }
109 
110 #endif /* __ASM_SH_SYSCALL_32_H */
111