/*
 * This file is subject to the terms and conditions of the GNU General Public
 * License.  See the file "COPYING" in the main directory of this archive
 * for more details.
 *
 * Copyright (C) 1995, 1996, 1997, 2000, 2001, 05 by Ralf Baechle
 * Copyright (C) 1999, 2000 Silicon Graphics, Inc.
 * Copyright (C) 2001 MIPS Technologies, Inc.
 */
#include <linux/capability.h>
#include <linux/errno.h>
#include <linux/linkage.h>
#include <linux/fs.h>
#include <linux/smp.h>
#include <linux/ptrace.h>
#include <linux/string.h>
#include <linux/syscalls.h>
#include <linux/file.h>
#include <linux/utsname.h>
#include <linux/unistd.h>
#include <linux/sem.h>
#include <linux/msg.h>
#include <linux/shm.h>
#include <linux/compiler.h>
#include <linux/ipc.h>
#include <linux/uaccess.h>
#include <linux/slab.h>
#include <linux/elf.h>
#include <linux/sched/task_stack.h>

#include <asm/asm.h>
#include <asm/asm-eva.h>
#include <asm/branch.h>
#include <asm/cachectl.h>
#include <asm/cacheflush.h>
#include <asm/asm-offsets.h>
#include <asm/signal.h>
#include <asm/sim.h>
#include <asm/shmparam.h>
#include <asm/sync.h>
#include <asm/sysmips.h>
#include <asm/syscalls.h>
#include <asm/switch_to.h>

/*
 * For historic reasons the pipe(2) syscall on MIPS has an unusual calling
 * convention.  It returns results in registers $v0 / $v1 which means there
 * is no need for it to do verify the validity of a userspace pointer
 * argument.  Historically that used to be expensive in Linux.  These days
 * the performance advantage is negligible.
 */
asmlinkage int sysm_pipe(void)
{
        int fd[2];
        int error = do_pipe_flags(fd, 0);
        if (error)
                return error;
        current_pt_regs()->regs[3] = fd[1];
        return fd[0];
}

SYSCALL_DEFINE6(mips_mmap, unsigned long, addr, unsigned long, len,
        unsigned long, prot, unsigned long, flags, unsigned long,
        fd, off_t, offset)
{
        if (offset & ~PAGE_MASK)
                return -EINVAL;
        return ksys_mmap_pgoff(addr, len, prot, flags, fd,
                               offset >> PAGE_SHIFT);
}

SYSCALL_DEFINE6(mips_mmap2, unsigned long, addr, unsigned long, len,
        unsigned long, prot, unsigned long, flags, unsigned long, fd,
        unsigned long, pgoff)
{
        if (pgoff & (~PAGE_MASK >> 12))
                return -EINVAL;

        return ksys_mmap_pgoff(addr, len, prot, flags, fd,
                               pgoff >> (PAGE_SHIFT - 12));
}

save_static_function(sys_fork);
save_static_function(sys_clone);
save_static_function(sys_clone3);

SYSCALL_DEFINE1(set_thread_area, unsigned long, addr)
{
        struct thread_info *ti = task_thread_info(current);

        ti->tp_value = addr;
        if (cpu_has_userlocal)
                write_c0_userlocal(addr);

        return 0;
}

static inline int mips_atomic_set(unsigned long addr, unsigned long new)
{
        unsigned long old, tmp;
        struct pt_regs *regs;
        unsigned int err;

        if (unlikely(addr & 3))
                return -EINVAL;

        if (unlikely(!access_ok((const void __user *)addr, 4)))
                return -EINVAL;

        if (cpu_has_llsc && IS_ENABLED(CONFIG_WAR_R10000_LLSC)) {
                __asm__ __volatile__ (
                "       .set    push                                    \n"
                "       .set    arch=r4000                              \n"
                "       li      %[err], 0                               \n"
                "1:     ll      %[old], (%[addr])                       \n"
                "       move    %[tmp], %[new]                          \n"
                "2:     sc      %[tmp], (%[addr])                       \n"
                "       beqzl   %[tmp], 1b                              \n"
                "3:                                                     \n"
                "       .insn                                           \n"
                "       .section .fixup,\"ax\"                          \n"
                "4:     li      %[err], %[efault]                       \n"
                "       j       3b                                      \n"
                "       .previous                                       \n"
                "       .section __ex_table,\"a\"                       \n"
                "       "STR(PTR_WD)"   1b, 4b                          \n"
                "       "STR(PTR_WD)"   2b, 4b                          \n"
                "       .previous                                       \n"
                "       .set    pop                                     \n"
                : [old] "=&r" (old),
                  [err] "=&r" (err),
                  [tmp] "=&r" (tmp)
                : [addr] "r" (addr),
                  [new] "r" (new),
                  [efault] "i" (-EFAULT)
                : "memory");
        } else if (cpu_has_llsc) {
                __asm__ __volatile__ (
                "       .set    push                                    \n"
                "       .set    "MIPS_ISA_ARCH_LEVEL"                   \n"
                "       li      %[err], 0                               \n"
                "1:                                                     \n"
                "       " __SYNC(full, loongson3_war) "                 \n"
                user_ll("%[old]", "(%[addr])")
                "       move    %[tmp], %[new]                          \n"
                "2:                                                     \n"
                user_sc("%[tmp]", "(%[addr])")
                "       beqz    %[tmp], 1b                              \n"
                "3:                                                     \n"
                "       .insn                                           \n"
                "       .section .fixup,\"ax\"                          \n"
                "5:     li      %[err], %[efault]                       \n"
                "       j       3b                                      \n"
                "       .previous                                       \n"
                "       .section __ex_table,\"a\"                       \n"
                "       "STR(PTR_WD)"   1b, 5b                          \n"
                "       "STR(PTR_WD)"   2b, 5b                          \n"
                "       .previous                                       \n"
                "       .set    pop                                     \n"
                : [old] "=&r" (old),
                  [err] "=&r" (err),
                  [tmp] "=&r" (tmp)
                : [addr] "r" (addr),
                  [new] "r" (new),
                  [efault] "i" (-EFAULT)
                : "memory");
        } else {
                do {
                        preempt_disable();
                        ll_bit = 1;
                        ll_task = current;
                        preempt_enable();

                        err = __get_user(old, (unsigned int *) addr);
                        err |= __put_user(new, (unsigned int *) addr);
                        if (err)
                                break;
                        rmb();
                } while (!ll_bit);
        }

        if (unlikely(err))
                return err;

        regs = current_pt_regs();
        regs->regs[2] = old;
        regs->regs[7] = 0;      /* No error */

        /*
         * Don't let your children do this ...
         */
        __asm__ __volatile__(
        "       move    $29, %0                                         \n"
        "       j       syscall_exit                                    \n"
        : /* no outputs */
        : "r" (regs));

        /* unreached.  Honestly.  */
        unreachable();
}

/*
 * mips_atomic_set() normally returns directly via syscall_exit potentially
 * clobbering static registers, so be sure to preserve them.
 */
save_static_function(sys_sysmips);

SYSCALL_DEFINE3(sysmips, long, cmd, long, arg1, long, arg2)
{
        switch (cmd) {
        case MIPS_ATOMIC_SET:
                return mips_atomic_set(arg1, arg2);

        case MIPS_FIXADE:
                if (arg1 & ~3)
                        return -EINVAL;

                if (arg1 & 1)
                        set_thread_flag(TIF_FIXADE);
                else
                        clear_thread_flag(TIF_FIXADE);
                if (arg1 & 2)
                        set_thread_flag(TIF_LOGADE);
                else
                        clear_thread_flag(TIF_LOGADE);

                return 0;

        case FLUSH_CACHE:
                __flush_cache_all();
                return 0;
        }

        return -EINVAL;
}

/*
 * No implemented yet ...
 */
SYSCALL_DEFINE3(cachectl, char *, addr, int, nbytes, int, op)
{
        return -ENOSYS;
}