xref: /openbmc/linux/arch/sh/include/asm/syscall_32.h (revision 8730046c)
1 #ifndef __ASM_SH_SYSCALL_32_H
2 #define __ASM_SH_SYSCALL_32_H
3 
4 #include <uapi/linux/audit.h>
5 #include <linux/kernel.h>
6 #include <linux/sched.h>
7 #include <linux/err.h>
8 #include <asm/ptrace.h>
9 
10 /* The system call number is given by the user in R3 */
11 static inline long syscall_get_nr(struct task_struct *task,
12 				  struct pt_regs *regs)
13 {
14 	return (regs->tra >= 0) ? regs->regs[3] : -1L;
15 }
16 
17 static inline void syscall_rollback(struct task_struct *task,
18 				    struct pt_regs *regs)
19 {
20 	/*
21 	 * XXX: This needs some thought. On SH we don't
22 	 * save away the original r0 value anywhere.
23 	 */
24 }
25 
26 static inline long syscall_get_error(struct task_struct *task,
27 				     struct pt_regs *regs)
28 {
29 	return IS_ERR_VALUE(regs->regs[0]) ? regs->regs[0] : 0;
30 }
31 
32 static inline long syscall_get_return_value(struct task_struct *task,
33 					    struct pt_regs *regs)
34 {
35 	return regs->regs[0];
36 }
37 
38 static inline void syscall_set_return_value(struct task_struct *task,
39 					    struct pt_regs *regs,
40 					    int error, long val)
41 {
42 	if (error)
43 		regs->regs[0] = -error;
44 	else
45 		regs->regs[0] = val;
46 }
47 
48 static inline void syscall_get_arguments(struct task_struct *task,
49 					 struct pt_regs *regs,
50 					 unsigned int i, unsigned int n,
51 					 unsigned long *args)
52 {
53 	/*
54 	 * Do this simply for now. If we need to start supporting
55 	 * fetching arguments from arbitrary indices, this will need some
56 	 * extra logic. Presently there are no in-tree users that depend
57 	 * on this behaviour.
58 	 */
59 	BUG_ON(i);
60 
61 	/* Argument pattern is: R4, R5, R6, R7, R0, R1 */
62 	switch (n) {
63 	case 6: args[5] = regs->regs[1];
64 	case 5: args[4] = regs->regs[0];
65 	case 4: args[3] = regs->regs[7];
66 	case 3: args[2] = regs->regs[6];
67 	case 2: args[1] = regs->regs[5];
68 	case 1:	args[0] = regs->regs[4];
69 	case 0:
70 		break;
71 	default:
72 		BUG();
73 	}
74 }
75 
76 static inline void syscall_set_arguments(struct task_struct *task,
77 					 struct pt_regs *regs,
78 					 unsigned int i, unsigned int n,
79 					 const unsigned long *args)
80 {
81 	/* Same note as above applies */
82 	BUG_ON(i);
83 
84 	switch (n) {
85 	case 6: regs->regs[1] = args[5];
86 	case 5: regs->regs[0] = args[4];
87 	case 4: regs->regs[7] = args[3];
88 	case 3: regs->regs[6] = args[2];
89 	case 2: regs->regs[5] = args[1];
90 	case 1: regs->regs[4] = args[0];
91 		break;
92 	default:
93 		BUG();
94 	}
95 }
96 
97 static inline int syscall_get_arch(void)
98 {
99 	int arch = AUDIT_ARCH_SH;
100 
101 #ifdef CONFIG_CPU_LITTLE_ENDIAN
102 	arch |= __AUDIT_ARCH_LE;
103 #endif
104 	return arch;
105 }
106 #endif /* __ASM_SH_SYSCALL_32_H */
107