diff options
Diffstat (limited to 'arch/frv/include/asm/syscall.h')
| -rw-r--r-- | arch/frv/include/asm/syscall.h | 123 |
1 files changed, 123 insertions, 0 deletions
diff --git a/arch/frv/include/asm/syscall.h b/arch/frv/include/asm/syscall.h new file mode 100644 index 0000000..70689eb --- /dev/null +++ b/arch/frv/include/asm/syscall.h @@ -0,0 +1,123 @@ +/* syscall parameter access functions + * + * Copyright (C) 2009 Red Hat, Inc. All Rights Reserved. + * Written by David Howells (dhowells@redhat.com) + * + * This program is free software; you can redistribute it and/or + * modify it under the terms of the GNU General Public Licence + * as published by the Free Software Foundation; either version + * 2 of the Licence, or (at your option) any later version. + */ + +#ifndef _ASM_SYSCALL_H +#define _ASM_SYSCALL_H + +#include <linux/err.h> +#include <asm/ptrace.h> + +/* + * Get the system call number or -1 + */ +static inline long syscall_get_nr(struct task_struct *task, + struct pt_regs *regs) +{ + return regs->syscallno; +} + +/* + * Restore the clobbered GR8 register + * (1st syscall arg was overwritten with syscall return or error) + */ +static inline void syscall_rollback(struct task_struct *task, + struct pt_regs *regs) +{ + regs->gr8 = regs->orig_gr8; +} + +/* + * See if the syscall return value is an error, returning it if it is and 0 if + * not + */ +static inline long syscall_get_error(struct task_struct *task, + struct pt_regs *regs) +{ + return IS_ERR_VALUE(regs->gr8) ? regs->gr8 : 0; +} + +/* + * Get the syscall return value + */ +static inline long syscall_get_return_value(struct task_struct *task, + struct pt_regs *regs) +{ + return regs->gr8; +} + +/* + * Set the syscall return value + */ +static inline void syscall_set_return_value(struct task_struct *task, + struct pt_regs *regs, + int error, long val) +{ + if (error) + regs->gr8 = -error; + else + regs->gr8 = val; +} + +/* + * Retrieve the system call arguments + */ +static inline void syscall_get_arguments(struct task_struct *task, + struct pt_regs *regs, + unsigned int i, unsigned int n, + unsigned long *args) +{ + /* + * Do this simply for now. If we need to start supporting + * fetching arguments from arbitrary indices, this will need some + * extra logic. Presently there are no in-tree users that depend + * on this behaviour. + */ + BUG_ON(i); + + /* Argument pattern is: GR8, GR9, GR10, GR11, GR12, GR13 */ + switch (n) { + case 6: args[5] = regs->gr13; + case 5: args[4] = regs->gr12; + case 4: args[3] = regs->gr11; + case 3: args[2] = regs->gr10; + case 2: args[1] = regs->gr9; + case 1: args[0] = regs->gr8; + break; + default: + BUG(); + } +} + +/* + * Alter the system call arguments + */ +static inline void syscall_set_arguments(struct task_struct *task, + struct pt_regs *regs, + unsigned int i, unsigned int n, + const unsigned long *args) +{ + /* Same note as above applies */ + BUG_ON(i); + + switch (n) { + case 6: regs->gr13 = args[5]; + case 5: regs->gr12 = args[4]; + case 4: regs->gr11 = args[3]; + case 3: regs->gr10 = args[2]; + case 2: regs->gr9 = args[1]; + case 1: regs->gr8 = args[0]; + break; + default: + BUG(); + } +} + +#endif /* _ASM_SYSCALL_H */ |