1/* 2 * linux/arch/m32r/kernel/sys_m32r.c 3 * 4 * This file contains various random system calls that 5 * have a non-standard calling sequence on the Linux/M32R platform. 6 * 7 * Taken from i386 version. 8 */ 9 10#include <linux/errno.h> 11#include <linux/sched.h> 12#include <linux/mm.h> 13#include <linux/fs.h> 14#include <linux/smp.h> 15#include <linux/sem.h> 16#include <linux/msg.h> 17#include <linux/shm.h> 18#include <linux/stat.h> 19#include <linux/syscalls.h> 20#include <linux/mman.h> 21#include <linux/file.h> 22#include <linux/utsname.h> 23#include <linux/ipc.h> 24 25#include <asm/uaccess.h> 26#include <asm/cachectl.h> 27#include <asm/cacheflush.h> 28#include <asm/syscall.h> 29#include <asm/unistd.h> 30 31/* 32 * sys_tas() - test-and-set 33 */ 34asmlinkage int sys_tas(int __user *addr) 35{ 36 int oldval; 37 38 if (!access_ok(VERIFY_WRITE, addr, sizeof (int))) 39 return -EFAULT; 40 41 /* atomic operation: 42 * oldval = *addr; *addr = 1; 43 */ 44 __asm__ __volatile__ ( 45 DCACHE_CLEAR("%0", "r4", "%1") 46 " .fillinsn\n" 47 "1:\n" 48 " lock %0, @%1 -> unlock %2, @%1\n" 49 "2:\n" 50 /* NOTE: 51 * The m32r processor can accept interrupts only 52 * at the 32-bit instruction boundary. 53 * So, in the above code, the "unlock" instruction 54 * can be executed continuously after the "lock" 55 * instruction execution without any interruptions. 56 */ 57 ".section .fixup,\"ax\"\n" 58 " .balign 4\n" 59 "3: ldi %0, #%3\n" 60 " seth r14, #high(2b)\n" 61 " or3 r14, r14, #low(2b)\n" 62 " jmp r14\n" 63 ".previous\n" 64 ".section __ex_table,\"a\"\n" 65 " .balign 4\n" 66 " .long 1b,3b\n" 67 ".previous\n" 68 : "=&r" (oldval) 69 : "r" (addr), "r" (1), "i"(-EFAULT) 70 : "r14", "memory" 71#ifdef CONFIG_CHIP_M32700_TS1 72 , "r4" 73#endif /* CONFIG_CHIP_M32700_TS1 */ 74 ); 75 76 return oldval; 77} 78 79asmlinkage int sys_cacheflush(void *addr, int bytes, int cache) 80{ 81 /* This should flush more selectively ... */ 82 _flush_cache_all(); 83 return 0; 84} 85 86asmlinkage int sys_cachectl(char *addr, int nbytes, int op) 87{ 88 /* Not implemented yet. */ 89 return -ENOSYS; 90} 91 92/* 93 * Do a system call from kernel instead of calling sys_execve so we 94 * end up with proper pt_regs. 95 */ 96int kernel_execve(const char *filename, 97 const char *const argv[], 98 const char *const envp[]) 99{ 100 register long __scno __asm__ ("r7") = __NR_execve; 101 register long __arg3 __asm__ ("r2") = (long)(envp); 102 register long __arg2 __asm__ ("r1") = (long)(argv); 103 register long __res __asm__ ("r0") = (long)(filename); 104 __asm__ __volatile__ ( 105 "trap #" SYSCALL_VECTOR "|| nop" 106 : "=r" (__res) 107 : "r" (__scno), "0" (__res), "r" (__arg2), 108 "r" (__arg3) 109 : "memory"); 110 return __res; 111} 112