xref: /openbmc/linux/arch/sh/include/asm/syscall_32.h (revision b04b4f78)
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 R3 */
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 long syscall_get_error(struct task_struct *task,
25 				     struct pt_regs *regs)
26 {
27 	return IS_ERR_VALUE(regs->regs[0]) ? regs->regs[0] : 0;
28 }
29 
30 static inline long syscall_get_return_value(struct task_struct *task,
31 					    struct pt_regs *regs)
32 {
33 	return regs->regs[0];
34 }
35 
36 static inline void syscall_set_return_value(struct task_struct *task,
37 					    struct pt_regs *regs,
38 					    int error, long val)
39 {
40 	if (error)
41 		regs->regs[0] = -error;
42 	else
43 		regs->regs[0] = val;
44 }
45 
46 static inline void syscall_get_arguments(struct task_struct *task,
47 					 struct pt_regs *regs,
48 					 unsigned int i, unsigned int n,
49 					 unsigned long *args)
50 {
51 	/*
52 	 * Do this simply for now. If we need to start supporting
53 	 * fetching arguments from arbitrary indices, this will need some
54 	 * extra logic. Presently there are no in-tree users that depend
55 	 * on this behaviour.
56 	 */
57 	BUG_ON(i);
58 
59 	/* Argument pattern is: R4, R5, R6, R7, R0, R1 */
60 	switch (n) {
61 	case 6: args[5] = regs->regs[1];
62 	case 5: args[4] = regs->regs[0];
63 	case 4: args[3] = regs->regs[7];
64 	case 3: args[2] = regs->regs[6];
65 	case 2: args[1] = regs->regs[5];
66 	case 1:	args[0] = regs->regs[4];
67 		break;
68 	default:
69 		BUG();
70 	}
71 }
72 
73 static inline void syscall_set_arguments(struct task_struct *task,
74 					 struct pt_regs *regs,
75 					 unsigned int i, unsigned int n,
76 					 const unsigned long *args)
77 {
78 	/* Same note as above applies */
79 	BUG_ON(i);
80 
81 	switch (n) {
82 	case 6: regs->regs[1] = args[5];
83 	case 5: regs->regs[0] = args[4];
84 	case 4: regs->regs[7] = args[3];
85 	case 3: regs->regs[6] = args[2];
86 	case 2: regs->regs[5] = args[1];
87 	case 1: regs->regs[4] = args[0];
88 		break;
89 	default:
90 		BUG();
91 	}
92 }
93 
94 #endif /* __ASM_SH_SYSCALL_32_H */
95