/* 
 * Copyright 2010 Stefan Lankes, Chair for Operating Systems,
 *                               RWTH Aachen University
 *
 * Licensed under the Apache License, Version 2.0 (the "License");
 * you may not use this file except in compliance with the License.
 * You may obtain a copy of the License at
 *
 *     http://www.apache.org/licenses/LICENSE-2.0
 *
 * Unless required by applicable law or agreed to in writing, software
 * distributed under the License is distributed on an "AS IS" BASIS,
 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
 * See the License for the specific language governing permissions and
 * limitations under the License.
 *
 * This file is part of MetalSVM.
 */

#include <metalsvm/stdio.h>
#include <metalsvm/errno.h>
#include <metalsvm/processor.h>
#include <metalsvm/errno.h>
#include <asm/io.h>
#include <asm/RCCE_lib.h>
#include <asm/SCC_API.h>

#ifdef CONFIG_ROCKCREEK

/* PSE bit for Pentium+ equals MPE (message buffer enable) flag in RCK! So, use it to create _PAGE_MPB symbol... */
#define _CR4_MPE 0x00000800

/*
 * Workaround to create a suitable argv array
 */
static char*	argv_strings[] = {"MetalSVM", "1", "533", "0"};
static char*	argv[4] = {[0 ... 3] = NULL};
static char**	rcce_argv = argv;
static int 	rcce_argc = 4;

/*
 * This is the modified MPB program, which is part of the RCCE distribution (src/mpb.c).
 *
 * This function clears the local MPB and resets the test&set register.
 */
static int scc_clear(void)
{
	int tmp, x, y, z, offset;
 
	// Find out who I am...
	tmp=ReadConfigReg(CRB_OWN+MYTILEID); 
	x=(tmp>>3) & 0x0f; // bits 06:03
	y=(tmp>>7) & 0x0f; // bits 10:07
	z=(tmp   ) & 0x07; // bits 02:00

	// Allocate Message Passing Buffer
	t_vcharp MPB;
	MPBalloc(&MPB, x, y, z, 1); 
	if (!MPB) {
		kprintf("Unable to allocate MPB for core %d of Tile x=%d, y= %d! Exiting.\n", z, x, y);
		return 255;
	}

	// zap own MPB
	for (offset=0; offset < 0x2000; offset+=8)
		*(volatile unsigned long long int*)(MPB+offset) = 0;

	// Clear test&set register write. Next read-access will read "1" (lock granted).
	SetConfigReg(CRB_ADDR(x,y)+((z)?LOCK1:LOCK0), 1); 

	return 0;
}

int scc_init(void)
{
	int num_ranks;
	int i, my_rank;

	kprintf("Initialize Rock Creek!\n");
	for(i=0; i<rcce_argc; i++)
		argv[i] = argv_strings[i];
	if (RCCE_init(&rcce_argc, &rcce_argv) != RCCE_SUCCESS)
		return -ENODEV;

	my_rank   = RCCE_ue();
	num_ranks = RCCE_num_ues();
	kprintf("Got rank %d of %d ranks\n", my_rank, num_ranks);

	/* Enable Messagepassing in CR4 */
	uint32_t cr4 = read_cr4();
	cr4 = cr4 | _CR4_MPE;
	write_cr4(cr4);

	i = ReadConfigReg(CRB_OWN+GLCFG0);
	kprintf("glcfg0 0x%x\n", i);

	/* synchronize before starting MetalSVM: */
	//RCCE_barrier(&RCCE_COMM_WORLD);

	kputs("Now, the SCC is initialized!\n");

	return 0;
}

#endif