/*
 * 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 long sys_mmap2(unsigned long addr, unsigned long len,
        unsigned long prot, unsigned long flags,
        unsigned long fd, unsigned long pgoff)
{
        int error = -EBADF;
        struct file *file = NULL;

        flags &= ~(MAP_EXECUTABLE | MAP_DENYWRITE);
        if (!(flags & MAP_ANONYMOUS)) {
                file = fget(fd);
                if (!file)
                        goto out;
        }

        down_write(&current->mm->mmap_sem);
        error = do_mmap_pgoff(file, addr, len, prot, flags, pgoff);
        up_write(&current->mm->mmap_sem);

        if (file)
                fput(file);
out:
        return error;
}

/*
 * sys_ipc() is the de-multiplexer for the SysV IPC calls..
 *
 * This is really horribly ugly.
 */
asmlinkage int sys_ipc(uint call, int first, int second,
                       int third, void __user *ptr, long fifth)
{
        int version, ret;

        version = call >> 16; /* hack for backward compatibility */
        call &= 0xffff;

        switch (call) {
        case SEMOP:
                return sys_semtimedop(first, (struct sembuf __user *)ptr,
                                      second, NULL);
        case SEMTIMEDOP:
                return sys_semtimedop(first, (struct sembuf __user *)ptr,
                                      second, (const struct timespec __user *)fifth);
        case SEMGET:
                return sys_semget (first, second, third);
        case SEMCTL: {
                union semun fourth;
                if (!ptr)
                        return -EINVAL;
                if (get_user(fourth.__pad, (void __user * __user *) ptr))
                        return -EFAULT;
                return sys_semctl (first, second, third, fourth);
                }

        case MSGSND:
                return sys_msgsnd (first, (struct msgbuf __user *) ptr,
                                   second, third);
        case MSGRCV:
                switch (version) {
                case 0: {
                        struct ipc_kludge tmp;
                        if (!ptr)
                                return -EINVAL;

                        if (copy_from_user(&tmp,
                                           (struct ipc_kludge __user *) ptr,
                                           sizeof (tmp)))
                                return -EFAULT;
                        return sys_msgrcv (first, tmp.msgp, second,
                                           tmp.msgtyp, third);
                        }
                default:
                        return sys_msgrcv (first,
                                           (struct msgbuf __user *) ptr,
                                           second, fifth, third);
                }
        case MSGGET:
                return sys_msgget ((key_t) first, second);
        case MSGCTL:
                return sys_msgctl (first, second,
                                   (struct msqid_ds __user *) ptr);
        case SHMAT: {
                ulong raddr;

                if (!access_ok(VERIFY_WRITE, (ulong __user *) third,
                                      sizeof(ulong)))
                        return -EFAULT;
                ret = do_shmat (first, (char __user *) ptr, second, &raddr);
                if (ret)
                        return ret;
                return put_user (raddr, (ulong __user *) third);
                }
        case SHMDT:
                return sys_shmdt ((char __user *)ptr);
        case SHMGET:
                return sys_shmget (first, second, third);
        case SHMCTL:
                return sys_shmctl (first, second,
                                   (struct shmid_ds __user *) ptr);
        default:
                return -ENOSYS;
        }
}

asmlinkage int sys_uname(struct old_utsname __user * name)
{
        int err;
        if (!name)
                return -EFAULT;
        down_read(&uts_sem);
        err = copy_to_user(name, utsname(), sizeof (*name));
        up_read(&uts_sem);
        return err?-EFAULT:0;
}

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;
}