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/*
* linux/arch/m32r/kernel/sys_m32r.c
*
* This file contains various random system calls that
* have a non-standard calling sequence on the Linux/M32R platform.
*
* Taken from i386 version.
*/
#include <linux/errno.h>
#include <linux/sched.h>
#include <linux/mm.h>
#include <linux/fs.h>
#include <linux/smp.h>
#include <linux/sem.h>
#include <linux/msg.h>
#include <linux/shm.h>
#include <linux/stat.h>
#include <linux/syscalls.h>
#include <linux/mman.h>
#include <linux/file.h>
#include <linux/utsname.h>
#include <linux/ipc.h>
#include <asm/uaccess.h>
#include <asm/cachectl.h>
#include <asm/cacheflush.h>
#include <asm/syscall.h>
#include <asm/unistd.h>
/*
* sys_tas() - test-and-set
*/
asmlinkage int sys_tas(int __user *addr)
{
int oldval;
if (!access_ok(VERIFY_WRITE, addr, sizeof (int)))
return -EFAULT;
/* atomic operation:
* oldval = *addr; *addr = 1;
*/
__asm__ __volatile__ (
DCACHE_CLEAR("%0", "r4", "%1")
" .fillinsn\n"
"1:\n"
" lock %0, @%1 -> unlock %2, @%1\n"
"2:\n"
/* NOTE:
* The m32r processor can accept interrupts only
* at the 32-bit instruction boundary.
* So, in the above code, the "unlock" instruction
* can be executed continuously after the "lock"
* instruction execution without any interruptions.
*/
".section .fixup,\"ax\"\n"
" .balign 4\n"
"3: ldi %0, #%3\n"
" seth r14, #high(2b)\n"
" or3 r14, r14, #low(2b)\n"
" jmp r14\n"
".previous\n"
".section __ex_table,\"a\"\n"
" .balign 4\n"
" .long 1b,3b\n"
".previous\n"
: "=&r" (oldval)
: "r" (addr), "r" (1), "i"(-EFAULT)
: "r14", "memory"
#ifdef CONFIG_CHIP_M32700_TS1
, "r4"
#endif /* CONFIG_CHIP_M32700_TS1 */
);
return oldval;
}
asmlinkage int sys_cacheflush(void *addr, int bytes, int cache)
{
/* This should flush more selectively ... */
_flush_cache_all();
return 0;
}
asmlinkage int sys_cachectl(char *addr, int nbytes, int op)
{
/* Not implemented yet. */
return -ENOSYS;
}
/*
* Do a system call from kernel instead of calling sys_execve so we
* end up with proper pt_regs.
*/
int kernel_execve(const char *filename, char *const argv[], char *const envp[])
{
register long __scno __asm__ ("r7") = __NR_execve;
register long __arg3 __asm__ ("r2") = (long)(envp);
register long __arg2 __asm__ ("r1") = (long)(argv);
register long __res __asm__ ("r0") = (long)(filename);
__asm__ __volatile__ (
"trap #" SYSCALL_VECTOR "|| nop"
: "=r" (__res)
: "r" (__scno), "0" (__res), "r" (__arg2),
"r" (__arg3)
: "memory");
return __res;
}
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