diff options
Diffstat (limited to 'arch/blackfin/include/asm/syscall.h')
-rw-r--r-- | arch/blackfin/include/asm/syscall.h | 96 |
1 files changed, 96 insertions, 0 deletions
diff --git a/arch/blackfin/include/asm/syscall.h b/arch/blackfin/include/asm/syscall.h new file mode 100644 index 0000000..4921a48 --- /dev/null +++ b/arch/blackfin/include/asm/syscall.h @@ -0,0 +1,96 @@ +/* + * Magic syscall break down functions + * + * Copyright 2010 Analog Devices Inc. + * + * Licensed under the GPL-2 or later. + */ + +#ifndef __ASM_BLACKFIN_SYSCALL_H__ +#define __ASM_BLACKFIN_SYSCALL_H__ + +/* + * Blackfin syscalls are simple: + * enter: + * p0: syscall number + * r{0,1,2,3,4,5}: syscall args 0,1,2,3,4,5 + * exit: + * r0: return/error value + */ + +#include <linux/err.h> +#include <linux/sched.h> +#include <asm/ptrace.h> + +static inline long +syscall_get_nr(struct task_struct *task, struct pt_regs *regs) +{ + return regs->p0; +} + +static inline void +syscall_rollback(struct task_struct *task, struct pt_regs *regs) +{ + regs->p0 = regs->orig_p0; +} + +static inline long +syscall_get_error(struct task_struct *task, struct pt_regs *regs) +{ + return IS_ERR_VALUE(regs->r0) ? regs->r0 : 0; +} + +static inline long +syscall_get_return_value(struct task_struct *task, struct pt_regs *regs) +{ + return regs->r0; +} + +static inline void +syscall_set_return_value(struct task_struct *task, struct pt_regs *regs, + int error, long val) +{ + regs->r0 = error ? -error : val; +} + +/** + * syscall_get_arguments() + * @task: unused + * @regs: the register layout to extract syscall arguments from + * @i: first syscall argument to extract + * @n: number of syscall arguments to extract + * @args: array to return the syscall arguments in + * + * args[0] gets i'th argument, args[n - 1] gets the i+n-1'th argument + */ +static inline void +syscall_get_arguments(struct task_struct *task, struct pt_regs *regs, + unsigned int i, unsigned int n, unsigned long *args) +{ + /* + * Assume the ptrace layout doesn't change -- r5 is first in memory, + * then r4, ..., then r0. So we simply reverse the ptrace register + * array in memory to store into the args array. + */ + long *aregs = ®s->r0 - i; + + BUG_ON(i > 5 || i + n > 6); + + while (n--) + *args++ = *aregs--; +} + +/* See syscall_get_arguments() comments */ +static inline void +syscall_set_arguments(struct task_struct *task, struct pt_regs *regs, + unsigned int i, unsigned int n, const unsigned long *args) +{ + long *aregs = ®s->r0 - i; + + BUG_ON(i > 5 || i + n > 6); + + while (n--) + *aregs-- = *args++; +} + +#endif |