xref: /openbmc/linux/arch/sh/include/asm/syscall_32.h (revision 82e6fdd6)
1 /* SPDX-License-Identifier: GPL-2.0 */
2 #ifndef __ASM_SH_SYSCALL_32_H
3 #define __ASM_SH_SYSCALL_32_H
4 
5 #include <uapi/linux/audit.h>
6 #include <linux/kernel.h>
7 #include <linux/sched.h>
8 #include <linux/err.h>
9 #include <asm/ptrace.h>
10 
11 /* The system call number is given by the user in R3 */
12 static inline long syscall_get_nr(struct task_struct *task,
13 				  struct pt_regs *regs)
14 {
15 	return (regs->tra >= 0) ? regs->regs[3] : -1L;
16 }
17 
18 static inline void syscall_rollback(struct task_struct *task,
19 				    struct pt_regs *regs)
20 {
21 	/*
22 	 * XXX: This needs some thought. On SH we don't
23 	 * save away the original r0 value anywhere.
24 	 */
25 }
26 
27 static inline long syscall_get_error(struct task_struct *task,
28 				     struct pt_regs *regs)
29 {
30 	return IS_ERR_VALUE(regs->regs[0]) ? regs->regs[0] : 0;
31 }
32 
33 static inline long syscall_get_return_value(struct task_struct *task,
34 					    struct pt_regs *regs)
35 {
36 	return regs->regs[0];
37 }
38 
39 static inline void syscall_set_return_value(struct task_struct *task,
40 					    struct pt_regs *regs,
41 					    int error, long val)
42 {
43 	if (error)
44 		regs->regs[0] = -error;
45 	else
46 		regs->regs[0] = val;
47 }
48 
49 static inline void syscall_get_arguments(struct task_struct *task,
50 					 struct pt_regs *regs,
51 					 unsigned int i, unsigned int n,
52 					 unsigned long *args)
53 {
54 	/*
55 	 * Do this simply for now. If we need to start supporting
56 	 * fetching arguments from arbitrary indices, this will need some
57 	 * extra logic. Presently there are no in-tree users that depend
58 	 * on this behaviour.
59 	 */
60 	BUG_ON(i);
61 
62 	/* Argument pattern is: R4, R5, R6, R7, R0, R1 */
63 	switch (n) {
64 	case 6: args[5] = regs->regs[1];
65 	case 5: args[4] = regs->regs[0];
66 	case 4: args[3] = regs->regs[7];
67 	case 3: args[2] = regs->regs[6];
68 	case 2: args[1] = regs->regs[5];
69 	case 1:	args[0] = regs->regs[4];
70 	case 0:
71 		break;
72 	default:
73 		BUG();
74 	}
75 }
76 
77 static inline void syscall_set_arguments(struct task_struct *task,
78 					 struct pt_regs *regs,
79 					 unsigned int i, unsigned int n,
80 					 const unsigned long *args)
81 {
82 	/* Same note as above applies */
83 	BUG_ON(i);
84 
85 	switch (n) {
86 	case 6: regs->regs[1] = args[5];
87 	case 5: regs->regs[0] = args[4];
88 	case 4: regs->regs[7] = args[3];
89 	case 3: regs->regs[6] = args[2];
90 	case 2: regs->regs[5] = args[1];
91 	case 1: regs->regs[4] = args[0];
92 		break;
93 	default:
94 		BUG();
95 	}
96 }
97 
98 static inline int syscall_get_arch(void)
99 {
100 	int arch = AUDIT_ARCH_SH;
101 
102 #ifdef CONFIG_CPU_LITTLE_ENDIAN
103 	arch |= __AUDIT_ARCH_LE;
104 #endif
105 	return arch;
106 }
107 #endif /* __ASM_SH_SYSCALL_32_H */
108