/*
* Copyright 2010 Tilera Corporation. All Rights Reserved.
*
* This program is free software; you can redistribute it and/or
* modify it under the terms of the GNU General Public License
* as published by the Free Software Foundation, version 2.
*
* This program is distributed in the hope that it will be useful, but
* WITHOUT ANY WARRANTY; without even the implied warranty of
* MERCHANTABILITY OR FITNESS FOR A PARTICULAR PURPOSE, GOOD TITLE or
* NON INFRINGEMENT. See the GNU General Public License for
* more details.
*/

/**
* @file
*
* ABI-related register definitions.
*/

#ifndef __ARCH_ABI_H__

#if !defined __need_int_reg_t && !defined __DOXYGEN__
# define __ARCH_ABI_H__
# include <arch/chip.h>
#endif

/* Provide the basic machine types. */
#ifndef __INT_REG_BITS

/** Number of bits in a register. */
#if defined __tilegx__
# define __INT_REG_BITS 64
#elif defined __tilepro__
# define __INT_REG_BITS 32
#elif !defined __need_int_reg_t
# include <arch/chip.h>
# define __INT_REG_BITS CHIP_WORD_SIZE()
#else
# error Unrecognized architecture with __need_int_reg_t
#endif

#if __INT_REG_BITS == 64

#ifndef __ASSEMBLER__
/** Unsigned type that can hold a register. */
typedef unsigned long long __uint_reg_t;

/** Signed type that can hold a register. */
typedef long long __int_reg_t;
#endif

/** String prefix to use for printf(). */
#define __INT_REG_FMT "ll"

#else

#ifndef __ASSEMBLER__
/** Unsigned type that can hold a register. */
typedef unsigned long __uint_reg_t;

/** Signed type that can hold a register. */
typedef long __int_reg_t;
#endif

/** String prefix to use for printf(). */
#define __INT_REG_FMT "l"

#endif
#endif /* __INT_REG_BITS */


#ifndef __need_int_reg_t


#ifndef __ASSEMBLER__
/** Unsigned type that can hold a register. */
typedef __uint_reg_t uint_reg_t;

/** Signed type that can hold a register. */
typedef __int_reg_t int_reg_t;
#endif

/** String prefix to use for printf(). */
#define INT_REG_FMT __INT_REG_FMT

/** Number of bits in a register. */
#define INT_REG_BITS __INT_REG_BITS


/* Registers 0 - 55 are "normal", but some perform special roles. */

#define TREG_FP 52 /**< Frame pointer. */
#define TREG_TP 53 /**< Thread pointer. */
#define TREG_SP 54 /**< Stack pointer. */
#define TREG_LR 55 /**< Link to calling function PC. */

/** Index of last normal general-purpose register. */
#define TREG_LAST_GPR 55

/* Registers 56 - 62 are "special" network registers. */

#define TREG_SN 56 /**< Static network access. */
#define TREG_IDN0 57 /**< IDN demux 0 access. */
#define TREG_IDN1 58 /**< IDN demux 1 access. */
#define TREG_UDN0 59 /**< UDN demux 0 access. */
#define TREG_UDN1 60 /**< UDN demux 1 access. */
#define TREG_UDN2 61 /**< UDN demux 2 access. */
#define TREG_UDN3 62 /**< UDN demux 3 access. */

/* Register 63 is the "special" zero register. */

#define TREG_ZERO 63 /**< "Zero" register; always reads as "0". */


/** By convention, this register is used to hold the syscall number. */
#define TREG_SYSCALL_NR 10

/** Name of register that holds the syscall number, for use in assembly. */
#define TREG_SYSCALL_NR_NAME r10


/**
* The ABI requires callers to allocate a caller state save area of
* this many bytes at the bottom of each stack frame.
*/
#define C_ABI_SAVE_AREA_SIZE (2 * (INT_REG_BITS / 8))

/**
* The operand to an 'info' opcode directing the backtracer to not
* try to find the calling frame.
*/
#define INFO_OP_CANNOT_BACKTRACE 2


#endif /* !__need_int_reg_t */

/* Make sure we later can get all the definitions and declarations. */
#undef __need_int_reg_t

#endif /* !__ARCH_ABI_H__ */