/*
   * 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/mm.h>

  #include <linux/fs.h>

  #include <linux/smp.h>

  #include <linux/mman.h>
  #include <linux/ptrace.h>
  #include <linux/sched.h>
  #include <linux/string.h>
  #include <linux/syscalls.h>
  #include <linux/file.h>
  #include <linux/slab.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/module.h>

  #include <linux/ipc.h>

  #include <linux/uaccess.h>

  #include <asm/asm.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/sysmips.h>
  #include <asm/uaccess.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(nabi_no_regargs volatile struct pt_regs regs)

  {
  	int fd[2];
  	int error, res;

  	error = do_pipe_flags(fd, 0);

  	if (error) {
  		res = error;
  		goto out;
  	}
  	regs.regs[3] = fd[1];
  	res = fd[0];
  out:
  	return res;
  }
  
  unsigned long shm_align_mask = PAGE_SIZE - 1;	/* Sane caches */

  EXPORT_SYMBOL(shm_align_mask);

  #define COLOUR_ALIGN(addr,pgoff)				\
  	((((addr) + shm_align_mask) & ~shm_align_mask) +	\
  	 (((pgoff) << PAGE_SHIFT) & shm_align_mask))
  
  unsigned long arch_get_unmapped_area(struct file *filp, unsigned long addr,
  	unsigned long len, unsigned long pgoff, unsigned long flags)
  {
  	struct vm_area_struct * vmm;
  	int do_color_align;
  	unsigned long task_size;
  
  	task_size = STACK_TOP;

  	if (len > task_size)
  		return -ENOMEM;

  	if (flags & MAP_FIXED) {

  		/* Even MAP_FIXED mappings must reside within task_size.  */
  		if (task_size - len < addr)
  			return -EINVAL;

  		/*
  		 * We do not accept a shared mapping if it would violate
  		 * cache aliasing constraints.
  		 */

  		if ((flags & MAP_SHARED) &&
  		    ((addr - (pgoff << PAGE_SHIFT)) & shm_align_mask))

  			return -EINVAL;
  		return addr;
  	}

  	do_color_align = 0;
  	if (filp || (flags & MAP_SHARED))
  		do_color_align = 1;
  	if (addr) {
  		if (do_color_align)
  			addr = COLOUR_ALIGN(addr, pgoff);
  		else
  			addr = PAGE_ALIGN(addr);
  		vmm = find_vma(current->mm, addr);
  		if (task_size - len >= addr &&
  		    (!vmm || addr + len <= vmm->vm_start))
  			return addr;
  	}
  	addr = TASK_UNMAPPED_BASE;
  	if (do_color_align)
  		addr = COLOUR_ALIGN(addr, pgoff);
  	else
  		addr = PAGE_ALIGN(addr);
  
  	for (vmm = find_vma(current->mm, addr); ; vmm = vmm->vm_next) {
  		/* At this point:  (!vmm || addr < vmm->vm_end). */
  		if (task_size - len < addr)
  			return -ENOMEM;
  		if (!vmm || addr + len <= vmm->vm_start)
  			return addr;
  		addr = vmm->vm_end;
  		if (do_color_align)
  			addr = COLOUR_ALIGN(addr, pgoff);
  	}
  }

  SYSCALL_DEFINE6(mips_mmap, unsigned long, addr, unsigned long, len,
  	unsigned long, prot, unsigned long, flags, unsigned long,
  	fd, off_t, offset)

  {
  	unsigned long result;
  
  	result = -EINVAL;
  	if (offset & ~PAGE_MASK)
  		goto out;

  	result = sys_mmap_pgoff(addr, len, prot, flags, fd, offset >> PAGE_SHIFT);

  
  out:
  	return result;
  }

  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 sys_mmap_pgoff(addr, len, prot, flags, fd, pgoff >> (PAGE_SHIFT-12));

  }
  
  save_static_function(sys_fork);

  static int __used noinline

  _sys_fork(nabi_no_regargs struct pt_regs regs)
  {
  	return do_fork(SIGCHLD, regs.regs[29], &regs, 0, NULL, NULL);
  }
  
  save_static_function(sys_clone);

  static int __used noinline

  _sys_clone(nabi_no_regargs struct pt_regs regs)
  {
  	unsigned long clone_flags;
  	unsigned long newsp;

  	int __user *parent_tidptr, *child_tidptr;

  
  	clone_flags = regs.regs[4];
  	newsp = regs.regs[5];
  	if (!newsp)
  		newsp = regs.regs[29];

  	parent_tidptr = (int __user *) regs.regs[6];
  #ifdef CONFIG_32BIT
  	/* We need to fetch the fifth argument off the stack.  */
  	child_tidptr = NULL;
  	if (clone_flags & (CLONE_CHILD_SETTID | CLONE_CHILD_CLEARTID)) {
  		int __user *__user *usp = (int __user *__user *) regs.regs[29];
  		if (regs.regs[2] == __NR_syscall) {
  			if (get_user (child_tidptr, &usp[5]))
  				return -EFAULT;
  		}
  		else if (get_user (child_tidptr, &usp[4]))
  			return -EFAULT;
  	}
  #else
  	child_tidptr = (int __user *) regs.regs[8];
  #endif

  	return do_fork(clone_flags, newsp, &regs, 0,
  	               parent_tidptr, child_tidptr);
  }
  
  /*
   * sys_execve() executes a new program.
   */
  asmlinkage int sys_execve(nabi_no_regargs struct pt_regs regs)
  {
  	int error;
  	char * filename;

  	filename = getname((char __user *) (long)regs.regs[4]);

  	error = PTR_ERR(filename);
  	if (IS_ERR(filename))
  		goto out;

  	error = do_execve(filename, (char __user *__user *) (long)regs.regs[5],
  	                  (char __user *__user *) (long)regs.regs[6], &regs);

  	putname(filename);
  
  out:
  	return error;
  }

  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(struct pt_regs *regs,
  	unsigned long addr, unsigned long new)

  {

  	unsigned long old, tmp;
  	unsigned int err;
  
  	if (unlikely(addr & 3))
  		return -EINVAL;
  
  	if (unlikely(!access_ok(VERIFY_WRITE, addr, 4)))
  		return -EINVAL;
  
  	if (cpu_has_llsc && R10000_LLSC_WAR) {
  		__asm__ __volatile__ (

  		"	.set	mips3					
  "

  		"	li	%[err], 0				
  "
  		"1:	ll	%[old], (%[addr])			
  "
  		"	move	%[tmp], %[new]				
  "
  		"2:	sc	%[tmp], (%[addr])			
  "
  		"	beqzl	%[tmp], 1b				
  "
  		"3:							
  "
  		"	.section .fixup,\"ax\"				
  "
  		"4:	li	%[err], %[efault]			
  "
  		"	j	3b					
  "
  		"	.previous					
  "
  		"	.section __ex_table,\"a\"			
  "
  		"	"STR(PTR)"	1b, 4b				
  "
  		"	"STR(PTR)"	2b, 4b				
  "
  		"	.previous					
  "

  		"	.set	mips0					
  "

  		: [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	mips3					
  "

  		"	li	%[err], 0				
  "
  		"1:	ll	%[old], (%[addr])			
  "
  		"	move	%[tmp], %[new]				
  "
  		"2:	sc	%[tmp], (%[addr])			
  "
  		"	bnez	%[tmp], 4f				
  "
  		"3:							
  "
  		"	.subsection 2					
  "
  		"4:	b	1b					
  "
  		"	.previous					
  "
  		"							
  "
  		"	.section .fixup,\"ax\"				
  "
  		"5:	li	%[err], %[efault]			
  "
  		"	j	3b					
  "
  		"	.previous					
  "
  		"	.section __ex_table,\"a\"			
  "
  		"	"STR(PTR)"	1b, 5b				
  "
  		"	"STR(PTR)"	2b, 5b				
  "
  		"	.previous					
  "

  		"	.set	mips0					
  "

  		: [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->regs[2] = old;
  	regs->regs[7] = 0;	/* No error */
  
  	/*
  	 * Don't let your children do this ...
  	 */
  	__asm__ __volatile__(
  	"	move	$29, %0						
  "
  	"	j	syscall_exit					
  "
  	: /* no outputs */
  	: "r" (regs));
  
  	/* unreached.  Honestly.  */
  	while (1);
  }
  
  save_static_function(sys_sysmips);
  static int __used noinline
  _sys_sysmips(nabi_no_regargs struct pt_regs regs)
  {
  	long cmd, arg1, arg2, arg3;
  
  	cmd = regs.regs[4];
  	arg1 = regs.regs[5];
  	arg2 = regs.regs[6];
  	arg3 = regs.regs[7];

  	switch (cmd) {

  	case MIPS_ATOMIC_SET:

  		return mips_atomic_set(&regs, 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_FIXADE);

  		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;
  }
  
  /*
   * If we ever come here the user sp is bad.  Zap the process right away.
   * Due to the bad stack signaling wouldn't work.
   */
  asmlinkage void bad_stack(void)
  {
  	do_exit(SIGSEGV);
  }

  
  /*
   * 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 unsigned long __a0 asm("$4") = (unsigned long) filename;
  	register unsigned long __a1 asm("$5") = (unsigned long) argv;
  	register unsigned long __a2 asm("$6") = (unsigned long) envp;
  	register unsigned long __a3 asm("$7");
  	unsigned long __v0;
  
  	__asm__ volatile ("					
  "
  	"	.set	noreorder				
  "
  	"	li	$2, %5		# __NR_execve		
  "
  	"	syscall						
  "
  	"	move	%0, $2					
  "
  	"	.set	reorder					
  "
  	: "=&r" (__v0), "=r" (__a3)
  	: "r" (__a0), "r" (__a1), "r" (__a2), "i" (__NR_execve)
  	: "$2", "$8", "$9", "$10", "$11", "$12", "$13", "$14", "$15", "$24",
  	  "memory");
  
  	if (__a3 == 0)
  		return __v0;
  
  	return -__v0;
  }