xref: /openbmc/linux/arch/sh/include/asm/syscall_32.h (revision 95e9fd10)
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 <linux/err.h>
7 #include <asm/ptrace.h>
8 
9 /* The system call number is given by the user in R3 */
10 static inline long syscall_get_nr(struct task_struct *task,
11 				  struct pt_regs *regs)
12 {
13 	return (regs->tra >= 0) ? regs->regs[3] : -1L;
14 }
15 
16 static inline void syscall_rollback(struct task_struct *task,
17 				    struct pt_regs *regs)
18 {
19 	/*
20 	 * XXX: This needs some thought. On SH we don't
21 	 * save away the original r0 value anywhere.
22 	 */
23 }
24 
25 static inline long syscall_get_error(struct task_struct *task,
26 				     struct pt_regs *regs)
27 {
28 	return IS_ERR_VALUE(regs->regs[0]) ? regs->regs[0] : 0;
29 }
30 
31 static inline long syscall_get_return_value(struct task_struct *task,
32 					    struct pt_regs *regs)
33 {
34 	return regs->regs[0];
35 }
36 
37 static inline void syscall_set_return_value(struct task_struct *task,
38 					    struct pt_regs *regs,
39 					    int error, long val)
40 {
41 	if (error)
42 		regs->regs[0] = -error;
43 	else
44 		regs->regs[0] = val;
45 }
46 
47 static inline void syscall_get_arguments(struct task_struct *task,
48 					 struct pt_regs *regs,
49 					 unsigned int i, unsigned int n,
50 					 unsigned long *args)
51 {
52 	/*
53 	 * Do this simply for now. If we need to start supporting
54 	 * fetching arguments from arbitrary indices, this will need some
55 	 * extra logic. Presently there are no in-tree users that depend
56 	 * on this behaviour.
57 	 */
58 	BUG_ON(i);
59 
60 	/* Argument pattern is: R4, R5, R6, R7, R0, R1 */
61 	switch (n) {
62 	case 6: args[5] = regs->regs[1];
63 	case 5: args[4] = regs->regs[0];
64 	case 4: args[3] = regs->regs[7];
65 	case 3: args[2] = regs->regs[6];
66 	case 2: args[1] = regs->regs[5];
67 	case 1:	args[0] = regs->regs[4];
68 	case 0:
69 		break;
70 	default:
71 		BUG();
72 	}
73 }
74 
75 static inline void syscall_set_arguments(struct task_struct *task,
76 					 struct pt_regs *regs,
77 					 unsigned int i, unsigned int n,
78 					 const unsigned long *args)
79 {
80 	/* Same note as above applies */
81 	BUG_ON(i);
82 
83 	switch (n) {
84 	case 6: regs->regs[1] = args[5];
85 	case 5: regs->regs[0] = args[4];
86 	case 4: regs->regs[7] = args[3];
87 	case 3: regs->regs[6] = args[2];
88 	case 2: regs->regs[5] = args[1];
89 	case 1: regs->regs[4] = args[0];
90 		break;
91 	default:
92 		BUG();
93 	}
94 }
95 
96 #endif /* __ASM_SH_SYSCALL_32_H */
97