/*
 * Copyright (c) 2000, 2001, 2002, 2003, 2004, 2005, 2008, 2009
 *	The President and Fellows of Harvard College.
 *
 * Redistribution and use in source and binary forms, with or without
 * modification, are permitted provided that the following conditions
 * are met:
 * 1. Redistributions of source code must retain the above copyright
 *    notice, this list of conditions and the following disclaimer.
 * 2. Redistributions in binary form must reproduce the above copyright
 *    notice, this list of conditions and the following disclaimer in the
 *    documentation and/or other materials provided with the distribution.
 * 3. Neither the name of the University nor the names of its contributors
 *    may be used to endorse or promote products derived from this software
 *    without specific prior written permission.
 *
 * THIS SOFTWARE IS PROVIDED BY THE UNIVERSITY AND CONTRIBUTORS ``AS IS'' AND
 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
 * ARE DISCLAIMED.  IN NO EVENT SHALL THE UNIVERSITY OR CONTRIBUTORS BE LIABLE
 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
 * SUCH DAMAGE.
 */

#ifndef _MIPS_TRAPFRAME_H_
#define _MIPS_TRAPFRAME_H_

/*
 * Structure describing what is saved on the stack during entry to
 * the exception handler.
 *
 * This must agree with the code in exception-*.S.
 */

struct trapframe {
  uint32_t tf_vaddr;  /* coprocessor 0 vaddr register */
  uint32_t tf_status; /* coprocessor 0 status register */
  uint32_t tf_cause;  /* coprocessor 0 cause register */
  uint32_t tf_lo;
  uint32_t tf_hi;
  uint32_t tf_ra; /* Saved register 31 */
  uint32_t tf_at; /* Saved register 1 (AT) */
  uint32_t tf_v0; /* Saved register 2 (v0) */
  uint32_t tf_v1; /* etc. */
  uint32_t tf_a0;
  uint32_t tf_a1;
  uint32_t tf_a2;
  uint32_t tf_a3;
  uint32_t tf_t0;
  uint32_t tf_t1;
  uint32_t tf_t2;
  uint32_t tf_t3;
  uint32_t tf_t4;
  uint32_t tf_t5;
  uint32_t tf_t6;
  uint32_t tf_t7;
  uint32_t tf_s0;
  uint32_t tf_s1;
  uint32_t tf_s2;
  uint32_t tf_s3;
  uint32_t tf_s4;
  uint32_t tf_s5;
  uint32_t tf_s6;
  uint32_t tf_s7;
  uint32_t tf_t8;
  uint32_t tf_t9;
  uint32_t tf_gp;
  uint32_t tf_sp;
  uint32_t tf_s8;
  uint32_t tf_epc; /* coprocessor 0 epc register */
};

/*
 * MIPS exception codes.
 */
#define EX_IRQ 0  /* Interrupt */
#define EX_MOD 1  /* TLB Modify (write to read-only page) */
#define EX_TLBL 2 /* TLB miss on load */
#define EX_TLBS 3 /* TLB miss on store */
#define EX_ADEL 4 /* Address error on load */
#define EX_ADES 5 /* Address error on store */
#define EX_IBE 6  /* Bus error on instruction fetch */
#define EX_DBE 7  /* Bus error on data load *or* store */
#define EX_SYS 8  /* Syscall */
#define EX_BP 9   /* Breakpoint */
#define EX_RI 10  /* Reserved (illegal) instruction */
#define EX_CPU 11 /* Coprocessor unusable */
#define EX_OVF 12 /* Arithmetic overflow */

/*
 * Function to enter user mode. Does not return. The trapframe must
 * be on the thread's own stack or bad things will happen.
 */
__DEAD void mips_usermode(struct trapframe *tf);

/*
 * Arrays used to load the kernel stack and curthread on trap entry.
 */
extern vaddr_t cpustacks[];
extern vaddr_t cputhreads[];

#endif /* _MIPS_TRAPFRAME_H_ */
