/*

   * arch/sh/kernel/process_64.c

   *

   * This file handles the architecture-dependent parts of process handling..

   *
   * Copyright (C) 2000, 2001  Paolo Alberelli

   * Copyright (C) 2003 - 2007  Paul Mundt

   * Copyright (C) 2003, 2004 Richard Curnow
   *
   * Started from SH3/4 version:
   *   Copyright (C) 1999, 2000  Niibe Yutaka & Kaz Kojima
   *
   *   In turn started from i386 version:
   *     Copyright (C) 1995  Linus Torvalds
   *

   * 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.

   */

  #include <linux/mm.h>

  #include <linux/fs.h>

  #include <linux/ptrace.h>

  #include <linux/reboot.h>

  #include <linux/slab.h>

  #include <linux/init.h>

  #include <linux/module.h>

  #include <linux/io.h>

  #include <asm/syscalls.h>

  #include <asm/uaccess.h>
  #include <asm/pgtable.h>

  #include <asm/mmu_context.h>

  #include <asm/fpu.h>

  
  struct task_struct *last_task_used_math = NULL;

  void show_regs(struct pt_regs *regs)

  {
  	unsigned long long ah, al, bh, bl, ch, cl;
  
  	printk("
  ");
  
  	ah = (regs->pc) >> 32;
  	al = (regs->pc) & 0xffffffff;
  	bh = (regs->regs[18]) >> 32;
  	bl = (regs->regs[18]) & 0xffffffff;
  	ch = (regs->regs[15]) >> 32;
  	cl = (regs->regs[15]) & 0xffffffff;
  	printk("PC  : %08Lx%08Lx LINK: %08Lx%08Lx SP  : %08Lx%08Lx
  ",
  	       ah, al, bh, bl, ch, cl);
  
  	ah = (regs->sr) >> 32;
  	al = (regs->sr) & 0xffffffff;
          asm volatile ("getcon   " __TEA ", %0" : "=r" (bh));
          asm volatile ("getcon   " __TEA ", %0" : "=r" (bl));
  	bh = (bh) >> 32;
  	bl = (bl) & 0xffffffff;
          asm volatile ("getcon   " __KCR0 ", %0" : "=r" (ch));
          asm volatile ("getcon   " __KCR0 ", %0" : "=r" (cl));
  	ch = (ch) >> 32;
  	cl = (cl) & 0xffffffff;
  	printk("SR  : %08Lx%08Lx TEA : %08Lx%08Lx KCR0: %08Lx%08Lx
  ",
  	       ah, al, bh, bl, ch, cl);
  
  	ah = (regs->regs[0]) >> 32;
  	al = (regs->regs[0]) & 0xffffffff;
  	bh = (regs->regs[1]) >> 32;
  	bl = (regs->regs[1]) & 0xffffffff;
  	ch = (regs->regs[2]) >> 32;
  	cl = (regs->regs[2]) & 0xffffffff;
  	printk("R0  : %08Lx%08Lx R1  : %08Lx%08Lx R2  : %08Lx%08Lx
  ",
  	       ah, al, bh, bl, ch, cl);
  
  	ah = (regs->regs[3]) >> 32;
  	al = (regs->regs[3]) & 0xffffffff;
  	bh = (regs->regs[4]) >> 32;
  	bl = (regs->regs[4]) & 0xffffffff;
  	ch = (regs->regs[5]) >> 32;
  	cl = (regs->regs[5]) & 0xffffffff;
  	printk("R3  : %08Lx%08Lx R4  : %08Lx%08Lx R5  : %08Lx%08Lx
  ",
  	       ah, al, bh, bl, ch, cl);
  
  	ah = (regs->regs[6]) >> 32;
  	al = (regs->regs[6]) & 0xffffffff;
  	bh = (regs->regs[7]) >> 32;
  	bl = (regs->regs[7]) & 0xffffffff;
  	ch = (regs->regs[8]) >> 32;
  	cl = (regs->regs[8]) & 0xffffffff;
  	printk("R6  : %08Lx%08Lx R7  : %08Lx%08Lx R8  : %08Lx%08Lx
  ",
  	       ah, al, bh, bl, ch, cl);
  
  	ah = (regs->regs[9]) >> 32;
  	al = (regs->regs[9]) & 0xffffffff;
  	bh = (regs->regs[10]) >> 32;
  	bl = (regs->regs[10]) & 0xffffffff;
  	ch = (regs->regs[11]) >> 32;
  	cl = (regs->regs[11]) & 0xffffffff;
  	printk("R9  : %08Lx%08Lx R10 : %08Lx%08Lx R11 : %08Lx%08Lx
  ",
  	       ah, al, bh, bl, ch, cl);
  
  	ah = (regs->regs[12]) >> 32;
  	al = (regs->regs[12]) & 0xffffffff;
  	bh = (regs->regs[13]) >> 32;
  	bl = (regs->regs[13]) & 0xffffffff;
  	ch = (regs->regs[14]) >> 32;
  	cl = (regs->regs[14]) & 0xffffffff;
  	printk("R12 : %08Lx%08Lx R13 : %08Lx%08Lx R14 : %08Lx%08Lx
  ",
  	       ah, al, bh, bl, ch, cl);
  
  	ah = (regs->regs[16]) >> 32;
  	al = (regs->regs[16]) & 0xffffffff;
  	bh = (regs->regs[17]) >> 32;
  	bl = (regs->regs[17]) & 0xffffffff;
  	ch = (regs->regs[19]) >> 32;
  	cl = (regs->regs[19]) & 0xffffffff;
  	printk("R16 : %08Lx%08Lx R17 : %08Lx%08Lx R19 : %08Lx%08Lx
  ",
  	       ah, al, bh, bl, ch, cl);
  
  	ah = (regs->regs[20]) >> 32;
  	al = (regs->regs[20]) & 0xffffffff;
  	bh = (regs->regs[21]) >> 32;
  	bl = (regs->regs[21]) & 0xffffffff;
  	ch = (regs->regs[22]) >> 32;
  	cl = (regs->regs[22]) & 0xffffffff;
  	printk("R20 : %08Lx%08Lx R21 : %08Lx%08Lx R22 : %08Lx%08Lx
  ",
  	       ah, al, bh, bl, ch, cl);
  
  	ah = (regs->regs[23]) >> 32;
  	al = (regs->regs[23]) & 0xffffffff;
  	bh = (regs->regs[24]) >> 32;
  	bl = (regs->regs[24]) & 0xffffffff;
  	ch = (regs->regs[25]) >> 32;
  	cl = (regs->regs[25]) & 0xffffffff;
  	printk("R23 : %08Lx%08Lx R24 : %08Lx%08Lx R25 : %08Lx%08Lx
  ",
  	       ah, al, bh, bl, ch, cl);
  
  	ah = (regs->regs[26]) >> 32;
  	al = (regs->regs[26]) & 0xffffffff;
  	bh = (regs->regs[27]) >> 32;
  	bl = (regs->regs[27]) & 0xffffffff;
  	ch = (regs->regs[28]) >> 32;
  	cl = (regs->regs[28]) & 0xffffffff;
  	printk("R26 : %08Lx%08Lx R27 : %08Lx%08Lx R28 : %08Lx%08Lx
  ",
  	       ah, al, bh, bl, ch, cl);
  
  	ah = (regs->regs[29]) >> 32;
  	al = (regs->regs[29]) & 0xffffffff;
  	bh = (regs->regs[30]) >> 32;
  	bl = (regs->regs[30]) & 0xffffffff;
  	ch = (regs->regs[31]) >> 32;
  	cl = (regs->regs[31]) & 0xffffffff;
  	printk("R29 : %08Lx%08Lx R30 : %08Lx%08Lx R31 : %08Lx%08Lx
  ",
  	       ah, al, bh, bl, ch, cl);
  
  	ah = (regs->regs[32]) >> 32;
  	al = (regs->regs[32]) & 0xffffffff;
  	bh = (regs->regs[33]) >> 32;
  	bl = (regs->regs[33]) & 0xffffffff;
  	ch = (regs->regs[34]) >> 32;
  	cl = (regs->regs[34]) & 0xffffffff;
  	printk("R32 : %08Lx%08Lx R33 : %08Lx%08Lx R34 : %08Lx%08Lx
  ",
  	       ah, al, bh, bl, ch, cl);
  
  	ah = (regs->regs[35]) >> 32;
  	al = (regs->regs[35]) & 0xffffffff;
  	bh = (regs->regs[36]) >> 32;
  	bl = (regs->regs[36]) & 0xffffffff;
  	ch = (regs->regs[37]) >> 32;
  	cl = (regs->regs[37]) & 0xffffffff;
  	printk("R35 : %08Lx%08Lx R36 : %08Lx%08Lx R37 : %08Lx%08Lx
  ",
  	       ah, al, bh, bl, ch, cl);
  
  	ah = (regs->regs[38]) >> 32;
  	al = (regs->regs[38]) & 0xffffffff;
  	bh = (regs->regs[39]) >> 32;
  	bl = (regs->regs[39]) & 0xffffffff;
  	ch = (regs->regs[40]) >> 32;
  	cl = (regs->regs[40]) & 0xffffffff;
  	printk("R38 : %08Lx%08Lx R39 : %08Lx%08Lx R40 : %08Lx%08Lx
  ",
  	       ah, al, bh, bl, ch, cl);
  
  	ah = (regs->regs[41]) >> 32;
  	al = (regs->regs[41]) & 0xffffffff;
  	bh = (regs->regs[42]) >> 32;
  	bl = (regs->regs[42]) & 0xffffffff;
  	ch = (regs->regs[43]) >> 32;
  	cl = (regs->regs[43]) & 0xffffffff;
  	printk("R41 : %08Lx%08Lx R42 : %08Lx%08Lx R43 : %08Lx%08Lx
  ",
  	       ah, al, bh, bl, ch, cl);
  
  	ah = (regs->regs[44]) >> 32;
  	al = (regs->regs[44]) & 0xffffffff;
  	bh = (regs->regs[45]) >> 32;
  	bl = (regs->regs[45]) & 0xffffffff;
  	ch = (regs->regs[46]) >> 32;
  	cl = (regs->regs[46]) & 0xffffffff;
  	printk("R44 : %08Lx%08Lx R45 : %08Lx%08Lx R46 : %08Lx%08Lx
  ",
  	       ah, al, bh, bl, ch, cl);
  
  	ah = (regs->regs[47]) >> 32;
  	al = (regs->regs[47]) & 0xffffffff;
  	bh = (regs->regs[48]) >> 32;
  	bl = (regs->regs[48]) & 0xffffffff;
  	ch = (regs->regs[49]) >> 32;
  	cl = (regs->regs[49]) & 0xffffffff;
  	printk("R47 : %08Lx%08Lx R48 : %08Lx%08Lx R49 : %08Lx%08Lx
  ",
  	       ah, al, bh, bl, ch, cl);
  
  	ah = (regs->regs[50]) >> 32;
  	al = (regs->regs[50]) & 0xffffffff;
  	bh = (regs->regs[51]) >> 32;
  	bl = (regs->regs[51]) & 0xffffffff;
  	ch = (regs->regs[52]) >> 32;
  	cl = (regs->regs[52]) & 0xffffffff;
  	printk("R50 : %08Lx%08Lx R51 : %08Lx%08Lx R52 : %08Lx%08Lx
  ",
  	       ah, al, bh, bl, ch, cl);
  
  	ah = (regs->regs[53]) >> 32;
  	al = (regs->regs[53]) & 0xffffffff;
  	bh = (regs->regs[54]) >> 32;
  	bl = (regs->regs[54]) & 0xffffffff;
  	ch = (regs->regs[55]) >> 32;
  	cl = (regs->regs[55]) & 0xffffffff;
  	printk("R53 : %08Lx%08Lx R54 : %08Lx%08Lx R55 : %08Lx%08Lx
  ",
  	       ah, al, bh, bl, ch, cl);
  
  	ah = (regs->regs[56]) >> 32;
  	al = (regs->regs[56]) & 0xffffffff;
  	bh = (regs->regs[57]) >> 32;
  	bl = (regs->regs[57]) & 0xffffffff;
  	ch = (regs->regs[58]) >> 32;
  	cl = (regs->regs[58]) & 0xffffffff;
  	printk("R56 : %08Lx%08Lx R57 : %08Lx%08Lx R58 : %08Lx%08Lx
  ",
  	       ah, al, bh, bl, ch, cl);
  
  	ah = (regs->regs[59]) >> 32;
  	al = (regs->regs[59]) & 0xffffffff;
  	bh = (regs->regs[60]) >> 32;
  	bl = (regs->regs[60]) & 0xffffffff;
  	ch = (regs->regs[61]) >> 32;
  	cl = (regs->regs[61]) & 0xffffffff;
  	printk("R59 : %08Lx%08Lx R60 : %08Lx%08Lx R61 : %08Lx%08Lx
  ",
  	       ah, al, bh, bl, ch, cl);
  
  	ah = (regs->regs[62]) >> 32;
  	al = (regs->regs[62]) & 0xffffffff;
  	bh = (regs->tregs[0]) >> 32;
  	bl = (regs->tregs[0]) & 0xffffffff;
  	ch = (regs->tregs[1]) >> 32;
  	cl = (regs->tregs[1]) & 0xffffffff;
  	printk("R62 : %08Lx%08Lx T0  : %08Lx%08Lx T1  : %08Lx%08Lx
  ",
  	       ah, al, bh, bl, ch, cl);
  
  	ah = (regs->tregs[2]) >> 32;
  	al = (regs->tregs[2]) & 0xffffffff;
  	bh = (regs->tregs[3]) >> 32;
  	bl = (regs->tregs[3]) & 0xffffffff;
  	ch = (regs->tregs[4]) >> 32;
  	cl = (regs->tregs[4]) & 0xffffffff;
  	printk("T2  : %08Lx%08Lx T3  : %08Lx%08Lx T4  : %08Lx%08Lx
  ",
  	       ah, al, bh, bl, ch, cl);
  
  	ah = (regs->tregs[5]) >> 32;
  	al = (regs->tregs[5]) & 0xffffffff;
  	bh = (regs->tregs[6]) >> 32;
  	bl = (regs->tregs[6]) & 0xffffffff;
  	ch = (regs->tregs[7]) >> 32;
  	cl = (regs->tregs[7]) & 0xffffffff;
  	printk("T5  : %08Lx%08Lx T6  : %08Lx%08Lx T7  : %08Lx%08Lx
  ",
  	       ah, al, bh, bl, ch, cl);
  
  	/*
  	 * If we're in kernel mode, dump the stack too..
  	 */
  	if (!user_mode(regs)) {
  		void show_stack(struct task_struct *tsk, unsigned long *sp);
  		unsigned long sp = regs->regs[15] & 0xffffffff;
  		struct task_struct *tsk = get_current();
  
  		tsk->thread.kregs = regs;
  
  		show_stack(tsk, (unsigned long *)sp);
  	}
  }

  /*
   * Create a kernel thread
   */

  __noreturn void kernel_thread_helper(void *arg, int (*fn)(void *))

  {
  	do_exit(fn(arg));
  }

  
  /*
   * This is the mechanism for creating a new kernel thread.
   *
   * NOTE! Only a kernel-only process(ie the swapper or direct descendants
   * who haven't done an "execve()") should use this: it will work within
   * a system call from a "real" process, but the process memory space will

   * not be freed until both the parent and the child have exited.

   */
  int kernel_thread(int (*fn)(void *), void * arg, unsigned long flags)
  {

  	struct pt_regs regs;

  	memset(&regs, 0, sizeof(regs));
  	regs.regs[2] = (unsigned long)arg;
  	regs.regs[3] = (unsigned long)fn;

  	regs.pc = (unsigned long)kernel_thread_helper;
  	regs.sr = (1 << 30);

  	/* Ok, create the new process.. */

  	return do_fork(flags | CLONE_VM | CLONE_UNTRACED, 0,

  		      &regs, 0, NULL, NULL);

  }

  EXPORT_SYMBOL(kernel_thread);

  
  /*
   * Free current thread data structures etc..
   */
  void exit_thread(void)
  {

  	/*
  	 * See arch/sparc/kernel/process.c for the precedent for doing
  	 * this -- RPC.
  	 *
  	 * The SH-5 FPU save/restore approach relies on
  	 * last_task_used_math pointing to a live task_struct.  When
  	 * another task tries to use the FPU for the 1st time, the FPUDIS
  	 * trap handling (see arch/sh/kernel/cpu/sh5/fpu.c) will save the
  	 * existing FPU state to the FP regs field within
  	 * last_task_used_math before re-loading the new task's FPU state
  	 * (or initialising it if the FPU has been used before).  So if
  	 * last_task_used_math is stale, and its page has already been
  	 * re-allocated for another use, the consequences are rather
  	 * grim. Unless we null it here, there is no other path through
  	 * which it would get safely nulled.
  	 */

  #ifdef CONFIG_SH_FPU
  	if (last_task_used_math == current) {
  		last_task_used_math = NULL;
  	}
  #endif
  }
  
  void flush_thread(void)
  {

  	/* Called by fs/exec.c (setup_new_exec) to remove traces of a

  	 * previously running executable. */
  #ifdef CONFIG_SH_FPU
  	if (last_task_used_math == current) {
  		last_task_used_math = NULL;
  	}
  	/* Force FPU state to be reinitialised after exec */
  	clear_used_math();
  #endif
  
  	/* if we are a kernel thread, about to change to user thread,
           * update kreg
           */
  	if(current->thread.kregs==&fake_swapper_regs) {
            current->thread.kregs =
               ((struct pt_regs *)(THREAD_SIZE + (unsigned long) current) - 1);
  	  current->thread.uregs = current->thread.kregs;
  	}
  }
  
  void release_thread(struct task_struct *dead_task)
  {
  	/* do nothing */
  }
  
  /* Fill in the fpu structure for a core dump.. */
  int dump_fpu(struct pt_regs *regs, elf_fpregset_t *fpu)
  {
  #ifdef CONFIG_SH_FPU
  	int fpvalid;
  	struct task_struct *tsk = current;
  
  	fpvalid = !!tsk_used_math(tsk);
  	if (fpvalid) {
  		if (current == last_task_used_math) {

  			enable_fpu();

  			save_fpu(tsk);

  			disable_fpu();

  			last_task_used_math = 0;
  			regs->sr |= SR_FD;
  		}

  		memcpy(fpu, &tsk->thread.xstate->hardfpu, sizeof(*fpu));

  	}
  
  	return fpvalid;
  #else
  	return 0; /* Task didn't use the fpu at all. */
  #endif
  }

  EXPORT_SYMBOL(dump_fpu);

  
  asmlinkage void ret_from_fork(void);

  int copy_thread(unsigned long clone_flags, unsigned long usp,

  		unsigned long unused,
  		struct task_struct *p, struct pt_regs *regs)
  {
  	struct pt_regs *childregs;

  
  #ifdef CONFIG_SH_FPU
  	if(last_task_used_math == current) {

  		enable_fpu();

  		save_fpu(current);

  		disable_fpu();

  		last_task_used_math = NULL;
  		regs->sr |= SR_FD;
  	}
  #endif
  	/* Copy from sh version */

  	childregs = (struct pt_regs *)(THREAD_SIZE + task_stack_page(p)) - 1;

  
  	*childregs = *regs;

  	/*
  	 * Sign extend the edited stack.
  	 * Note that thread.pc and thread.pc will stay
  	 * 32-bit wide and context switch must take care
  	 * of NEFF sign extension.
  	 */

  	if (user_mode(regs)) {

  		childregs->regs[15] = neff_sign_extend(usp);

  		p->thread.uregs = childregs;
  	} else {

  		childregs->regs[15] =
  			neff_sign_extend((unsigned long)task_stack_page(p) +
  					 THREAD_SIZE);

  	}
  
  	childregs->regs[9] = 0; /* Set return value for child */
  	childregs->sr |= SR_FD; /* Invalidate FPU flag */
  
  	p->thread.sp = (unsigned long) childregs;
  	p->thread.pc = (unsigned long) ret_from_fork;

  	return 0;
  }

  asmlinkage int sys_fork(unsigned long r2, unsigned long r3,
  			unsigned long r4, unsigned long r5,
  			unsigned long r6, unsigned long r7,
  			struct pt_regs *pregs)
  {
  	return do_fork(SIGCHLD, pregs->regs[15], pregs, 0, 0, 0);
  }
  
  asmlinkage int sys_clone(unsigned long clone_flags, unsigned long newsp,
  			 unsigned long r4, unsigned long r5,
  			 unsigned long r6, unsigned long r7,
  			 struct pt_regs *pregs)
  {
  	if (!newsp)
  		newsp = pregs->regs[15];
  	return do_fork(clone_flags, newsp, pregs, 0, 0, 0);
  }
  
  /*
   * This is trivial, and on the face of it looks like it
   * could equally well be done in user mode.
   *
   * Not so, for quite unobvious reasons - register pressure.
   * In user mode vfork() cannot have a stack frame, and if
   * done by calling the "clone()" system call directly, you
   * do not have enough call-clobbered registers to hold all
   * the information you need.
   */
  asmlinkage int sys_vfork(unsigned long r2, unsigned long r3,
  			 unsigned long r4, unsigned long r5,
  			 unsigned long r6, unsigned long r7,
  			 struct pt_regs *pregs)
  {
  	return do_fork(CLONE_VFORK | CLONE_VM | SIGCHLD, pregs->regs[15], pregs, 0, 0, 0);
  }
  
  /*
   * sys_execve() executes a new program.
   */

  asmlinkage int sys_execve(const char *ufilename, char **uargv,

  			  char **uenvp, unsigned long r5,
  			  unsigned long r6, unsigned long r7,
  			  struct pt_regs *pregs)
  {
  	int error;
  	char *filename;

  	filename = getname((char __user *)ufilename);
  	error = PTR_ERR(filename);
  	if (IS_ERR(filename))
  		goto out;
  
  	error = do_execve(filename,

  			  (const char __user *const __user *)uargv,
  			  (const char __user *const __user *)uenvp,

  			  pregs);

  	putname(filename);
  out:

  	return error;
  }

  #ifdef CONFIG_FRAME_POINTER

  static int in_sh64_switch_to(unsigned long pc)
  {
  	extern char __sh64_switch_to_end;
  	/* For a sleeping task, the PC is somewhere in the middle of the function,
  	   so we don't have to worry about masking the LSB off */
  	return (pc >= (unsigned long) sh64_switch_to) &&
  	       (pc < (unsigned long) &__sh64_switch_to_end);
  }

  #endif

  
  unsigned long get_wchan(struct task_struct *p)
  {

  	unsigned long pc;
  
  	if (!p || p == current || p->state == TASK_RUNNING)
  		return 0;
  
  	/*
  	 * The same comment as on the Alpha applies here, too ...
  	 */
  	pc = thread_saved_pc(p);
  
  #ifdef CONFIG_FRAME_POINTER
  	if (in_sh64_switch_to(pc)) {

  		unsigned long schedule_fp;
  		unsigned long sh64_switch_to_fp;
  		unsigned long schedule_caller_pc;

  		sh64_switch_to_fp = (long) p->thread.sp;
  		/* r14 is saved at offset 4 in the sh64_switch_to frame */
  		schedule_fp = *(unsigned long *) (long)(sh64_switch_to_fp + 4);
  
  		/* and the caller of 'schedule' is (currently!) saved at offset 24
  		   in the frame of schedule (from disasm) */
  		schedule_caller_pc = *(unsigned long *) (long)(schedule_fp + 24);
  		return schedule_caller_pc;
  	}
  #endif
  	return pc;
  }