/*
 * Copyright (c) 2002,2003 Hewlett-Packard Company
 *
 * Permission is hereby granted, free of charge, to any person obtaining a
 * copy of this software and associated documentation files (the "Software"),
 * to deal in the Software without restriction, including without limitation
 * the rights to use, copy, modify, merge, publish, distribute, sublicense,
 * and/or sell copies of the Software, and to permit persons to whom the
 * Software is furnished to do so, subject to the following conditions:
 *
 * The above copyright notice and this permission notice shall be included
 * in all copies or substantial portions of the Software.
 *
 * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
 * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
 * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL
 * THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
 * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING
 * FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER
 * DEALINGS IN THE SOFTWARE.
 */

#include "uwx_env.h"
#include "uwx_context.h"
#include "uwx_scoreboard.h"
#include "uwx_step.h"
#include "uwx_trace.h"

int uwx_init_context(
    struct uwx_env *env,
    uint64_t ip,
    uint64_t sp,
    uint64_t bsp,
    uint64_t cfm)
{
    int i;

    if (env == 0)
	return UWX_ERR_NOENV;

    env->context.special[UWX_REG_IP] = ip;
    env->context.special[UWX_REG_SP] = sp;
    env->context.special[UWX_REG_BSP] = bsp;
    env->context.special[UWX_REG_CFM] = cfm;
    for (i = UWX_REG_RP; i < NSPECIALREG; i++)
	env->context.special[i] = 0;
    for (i = 0; i < NPRESERVEDGR; i++)
	env->context.gr[i] = 0;
    env->context.valid_regs = VALID_BASIC4;
    env->context.valid_frs = 0;
    env->rstate = 0;
    (void)uwx_init_history(env);
    return UWX_OK;
}

int uwx_get_reg(struct uwx_env *env, int regid, uint64_t *valp)
{
    int status;
    int sor;
    int rrb_gr;
    uint64_t bsp;
    int n;

    if (env == 0)
	return UWX_ERR_NOENV;

    status = UWX_OK;

    if (regid == UWX_REG_GR(12))
	regid = UWX_REG_SP;
    if (regid < NSPECIALREG && (env->context.valid_regs & (1 << regid)))
	*valp = env->context.special[regid];
    else if (regid == UWX_REG_PSP || regid == UWX_REG_RP ||
					regid == UWX_REG_PFS) {
	status = uwx_restore_markers(env);
	if (status != UWX_OK)
	    return status;
	*valp = env->context.special[regid];
    }
    else if (regid >= UWX_REG_GR(4) && regid <= UWX_REG_GR(7) &&
		(env->context.valid_regs &
		    (1 << (regid - UWX_REG_GR(4) + VALID_GR_SHIFT))) )
	*valp = env->context.gr[regid - UWX_REG_GR(4)];
    else if (regid >= UWX_REG_GR(32) && regid <= UWX_REG_GR(127)) {
	if (env->copyin == 0)
	    return UWX_ERR_NOCALLBACKS;
	bsp = env->context.special[UWX_REG_BSP];
	TRACE_C_GET_REG(regid, bsp)
	regid -= UWX_REG_GR(32);
	sor = (((int) env->context.special[UWX_REG_CFM] >> 14) & 0x0f) * 8;
	rrb_gr = ((int) env->context.special[UWX_REG_CFM] >> 18) & 0x7f;
	if (sor != 0 && rrb_gr != 0 && regid < sor) {
	    TRACE_C_ROTATE_GR(regid, sor, rrb_gr, (regid+rrb_gr)%sor)
	    regid = (regid + rrb_gr) % sor;
	}
	bsp = uwx_add_to_bsp(bsp, regid);
	n = (*env->copyin)(UWX_COPYIN_RSTACK, (char *)valp,
		    bsp, DWORDSZ, env->cb_token);
	if (n != DWORDSZ)
	    status = UWX_ERR_COPYIN_RSTK;
    }
    else if (regid == UWX_REG_GR(0))
	*valp = 0;
    else if (regid >= UWX_REG_BR(1) && regid <= UWX_REG_BR(5) &&
		(env->context.valid_regs &
		    (1 << (regid - UWX_REG_BR(1) + VALID_BR_SHIFT))) )
	*valp = env->context.br[regid - UWX_REG_BR(1)];
    else if (regid >= UWX_REG_FR(2) && regid <= UWX_REG_FR(5) &&
	    (env->context.valid_frs & (1 << (regid - UWX_REG_FR(2)))) ) {
	valp[0] = env->context.fr[regid - UWX_REG_FR(2)].part0;
	valp[1] = env->context.fr[regid - UWX_REG_FR(2)].part1;
    }
    else if (regid >= UWX_REG_FR(16) && regid <= UWX_REG_FR(31) &&
	    (env->context.valid_frs & (1 << (regid - UWX_REG_FR(16) + 4))) ) {
	valp[0] = env->context.fr[regid - UWX_REG_FR(16) + 4].part0;
	valp[1] = env->context.fr[regid - UWX_REG_FR(16) + 4].part1;
    }
    else if ( (regid < NSPECIALREG) ||
		(regid >= UWX_REG_GR(1) && regid <= UWX_REG_GR(31)) ||
		(regid >= UWX_REG_BR(0) && regid <= UWX_REG_BR(7)) ) {
	if (env->copyin == 0)
	    return UWX_ERR_NOCALLBACKS;
	n = (*env->copyin)(UWX_COPYIN_REG, (char *)valp,
			    regid, DWORDSZ, env->cb_token);
	if (n != DWORDSZ)
	    status = UWX_ERR_COPYIN_REG;
    }
    else if (regid >= UWX_REG_FR(2) && regid <= UWX_REG_FR(127)) {
	if (env->copyin == 0)
	    return UWX_ERR_NOCALLBACKS;
	n = (*env->copyin)(UWX_COPYIN_REG, (char *)valp,
			    regid, 2*DWORDSZ, env->cb_token);
	if (n != 2*DWORDSZ)
	    status = UWX_ERR_COPYIN_REG;
    }
    else if (regid == UWX_REG_FR(0)) {
	valp[0] = 0;
	valp[1] = 0;
    }
    else if (regid == UWX_REG_FR(1)) {
	valp[0] = 0x000000000000ffffULL;
	valp[1] = 0x8000000000000000ULL;
    }
    else
	status = UWX_ERR_BADREGID;
    return status;
}

int uwx_get_nat(struct uwx_env *env, int regid, int *natp)
{
    int status;
    int sor;
    int rrb_gr;
    uint64_t bsp;
    uint64_t natcollp;
    uint64_t natcoll;
    int n;

    if (env == 0)
	return UWX_ERR_NOENV;

    status = UWX_OK;

    if (regid >= UWX_REG_GR(4) && regid <= UWX_REG_GR(7) &&
		(env->context.valid_regs &
		    (1 << (regid - UWX_REG_GR(4) + VALID_GR_SHIFT))) ) {
	*natp = (env->context.special[UWX_REG_PRIUNAT] >>
				(regid - UWX_REG_GR(4)) ) & 0x01;
    }
    else if (regid >= UWX_REG_GR(32) && regid <= UWX_REG_GR(127)) {
	if (env->copyin == 0)
	    return UWX_ERR_NOCALLBACKS;
	bsp = env->context.special[UWX_REG_BSP];
	regid -= UWX_REG_GR(32);
	sor = (((int) env->context.special[UWX_REG_CFM] >> 14) & 0x0f) * 8;
	rrb_gr = ((int) env->context.special[UWX_REG_CFM] >> 18) & 0x7f;
	if (sor != 0 && rrb_gr != 0 && regid < sor) {
	    regid = (regid + rrb_gr) % sor;
	}
	bsp = uwx_add_to_bsp(bsp, regid);
	natcollp = bsp | 0x01f8;
	if (natcollp >= bsp)
	    n = (*env->copyin)(UWX_COPYIN_REG, (char *)&natcoll,
			(uint64_t)UWX_REG_AR_RNAT, DWORDSZ, env->cb_token);
	else
	    n = (*env->copyin)(UWX_COPYIN_RSTACK, (char *)&natcoll,
			bsp, DWORDSZ, env->cb_token);
	if (n != DWORDSZ)
	    return UWX_ERR_COPYIN_RSTK;
	*natp = (int)(natcoll >> (((int)bsp >> 3) & 0x3f)) & 0x01;
    }
    else if (regid == UWX_REG_GR(0))
	*natp = 0;
    else
	status = UWX_ERR_BADREGID;
    return status;
}

int uwx_get_spill_loc(struct uwx_env *env, int regid, uint64_t *dispp)
{
    int status;
    int sor;
    int rrb_gr;
    uint64_t bsp;

    if (env == 0)
	return UWX_ERR_NOENV;

    status = UWX_OK;

    if (regid == UWX_REG_GR(12))
	regid = UWX_REG_SP;
    if (regid < NSPECIALREG)
	*dispp = env->history.special[regid];
    else if (regid >= UWX_REG_GR(4) && regid <= UWX_REG_GR(7))
	*dispp = env->history.gr[regid - UWX_REG_GR(4)];
    else if (regid >= UWX_REG_GR(32) && regid <= UWX_REG_GR(127)) {
	bsp = env->context.special[UWX_REG_BSP];
	regid -= UWX_REG_GR(32);
	sor = (((int) env->context.special[UWX_REG_CFM] >> 14) & 0x0f) * 8;
	rrb_gr = ((int) env->context.special[UWX_REG_CFM] >> 18) & 0x7f;
	if (sor != 0 && rrb_gr != 0 && regid < sor)
	    regid = (regid + rrb_gr) % sor;
	bsp = uwx_add_to_bsp(bsp, regid);
	*dispp = UWX_DISP_RSTK(bsp);
    }
    else if (regid >= UWX_REG_BR(1) && regid <= UWX_REG_GR(5))
	*dispp = env->history.br[regid - UWX_REG_BR(1)];
    else if (regid >= UWX_REG_FR(2) && regid <= UWX_REG_FR(5))
	*dispp = env->history.fr[regid - UWX_REG_FR(2)];
    else if (regid >= UWX_REG_FR(16) && regid <= UWX_REG_FR(31))
	*dispp = env->history.fr[regid - UWX_REG_FR(16) + 4];
    else if ( (regid >= UWX_REG_GR(1) && regid <= UWX_REG_GR(31)) ||
		(regid >= UWX_REG_BR(0) && regid <= UWX_REG_BR(7)) ||
		(regid >= UWX_REG_FR(2) && regid <= UWX_REG_FR(127)) )
	*dispp = UWX_DISP_REG(regid);
    else
	status = UWX_ERR_BADREGID;
    return status;
}

int uwx_set_reg(struct uwx_env *env, int regid, uint64_t val)
{
    int status;

    if (env == 0)
	return UWX_ERR_NOENV;

    if (regid == UWX_REG_GR(12))
	regid = UWX_REG_SP;
    if (regid < NSPECIALREG) {
	env->context.special[regid] = val;
	env->context.valid_regs |= 1 << regid;
	status = UWX_OK;
    }
    else if (regid >= UWX_REG_GR(4) && regid <= UWX_REG_GR(7)) {
	env->context.gr[regid - UWX_REG_GR(4)] = val;
	env->context.valid_regs |=
			1 << (regid - UWX_REG_GR(4) + VALID_GR_SHIFT);
	status = UWX_OK;
    }
    else if (regid >= UWX_REG_GR(32) && regid <= UWX_REG_GR(127)) {
	status = UWX_ERR_BADREGID;
    }
    else if (regid >= UWX_REG_BR(1) && regid <= UWX_REG_BR(5)) {
	env->context.br[regid - UWX_REG_BR(1)] = val;
	env->context.valid_regs |=
			1 << (regid - UWX_REG_BR(1) + VALID_BR_SHIFT);
	status = UWX_OK;
    }
    else
	status = UWX_ERR_BADREGID;
    return status;
}

int uwx_set_fr(struct uwx_env *env, int regid, uint64_t *val)
{

    if (regid >= UWX_REG_FR(2) && regid <= UWX_REG_FR(5))
	regid -= UWX_REG_FR(2);
    else if (regid >= UWX_REG_FR(16) && regid <= UWX_REG_FR(31))
	regid -= UWX_REG_FR(16) - 4;
    else
	return UWX_ERR_BADREGID;

    env->context.fr[regid].part0 = val[0];
    env->context.fr[regid].part1 = val[1];
    env->context.valid_frs |= 1 << regid;
    env->nsbreg = NSBREG;
    return UWX_OK;
}

uint64_t uwx_add_to_bsp(uint64_t bsp, int nslots)
{
    int bias;

    /*
     *  Here's a picture of the backing store as modeled in
     *  the computations below. "X" marks NaT collections at
     *  every 0x1f8 mod 0x200 address.
     *
     *  To make the NaT adjustments easier, we bias the current bsp
     *  by enough slots to place it at the previous NaT collection.
     *  Then we need to add the bias to the number of slots,
     *  then add 1 for every 63 slots to account for NaT collections.
     *  Then we can remove the bias again and add the adjusted
     *  number of slots to the bsp.
     *
     *   0                           1f8                             3f8
     *  +---------------------------------------------------------------+
     *  |                              X                               X|
     *  +---------------------------------------------------------------+
     *   <-------- bias -------->
     *                           <--- nslots --->
     *                           ^
     *                           |
     *                          bsp
     *   <------- adjusted (nslots + bias) ------->

     *  When subtracting from bsp, we bias the bsp in the opposite
     *  direction so that it is at the next NaT collection.
     *
     *   0                           1f8                             3f8
     *  +---------------------------------------------------------------+
     *  |                              X                               X|
     *  +---------------------------------------------------------------+
     *                                           <------- bias ------->
     *                           <--- nslots --->
     *                                           ^
     *                                           |
     *                                          bsp
     *                         <------ adjusted (nslots + bias) ------>
     */

    if (nslots > 0) {
	bias = ((unsigned int)bsp & 0x1f8) / DWORDSZ;
	nslots += (nslots + bias) / 63;
    }
    else if (nslots < 0) {
	bias = (0x1f8 - ((unsigned int)bsp & 0x1f8)) / DWORDSZ;
	nslots -= (-nslots + bias) / 63;
    }
    return bsp + nslots * DWORDSZ;
}