/* 
 * 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 COND */

#include <metalsvm/stdio.h>
#include <metalsvm/errno.h>
#include <metalsvm/processor.h>
#include <metalsvm/errno.h>
#include <asm/io.h>
#include <asm/irqflags.h>
#include <asm/irq.h>
#ifdef CONFIG_ROCKCREEK
#include <asm/RCCE.h>
#include <asm/RCCE_lib.h>
#include <asm/iRCCE.h>
#include <asm/SCC_API.h>
#include <asm/icc.h>

#define IRQ_STATUS				0xD000
#define IRQ_MASK				0xD200
#define IRQ_RESET				0xD400
#define IRQ_REQUEST				0xD600
#define IRQ_CONFIG				0xD800

#include <net/mmnif.h>


bootinfo_t* bootinfo = (bootinfo_t*) SCC_BOOTINFO;
static int num_ues, my_ue;

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

/* maximal number of SCC's cores */
#define MAX_SCC_CORES	(NUM_ROWS*NUM_COLS*NUM_CORES)

/*
 * 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;

	// Initialize API
	InitAPI(0);
 
	// 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); 

	// frees Message Passing Buffer
	MPBunalloc(&MPB);

	return 0;
}

static void intr_handler(struct state *s)
{
	// reset appropriate bit in the core configuration register
	int tmp, z;

#ifdef CONFIG_LWIP
	mmnif_irqhandler();
#endif

	z = Z_PID(RC_COREID[my_ue]);
	tmp=ReadConfigReg(CRB_OWN + (z==0 ? GLCFG0 : GLCFG1));
	tmp &= ~2;
	SetConfigReg(CRB_OWN + (z==0 ? GLCFG0 : GLCFG1), tmp);
}

int icc_init(void)
{
	int i, z, tmp;
	uint64_t start, end, ticks, freq = 533;
	uint32_t cr4;

	kputs("Initialize Rock Creek!\n");

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

	kprintf("address of the initrd: 0x%x\n", bootinfo->addr);
	kprintf("size of the initrd: %d\n", bootinfo->size);
	kprintf("rcce argc = %d\n", bootinfo->argc);
	for(i=0; i<bootinfo->argc; i++)
		kprintf("rcce argv[%d] = %s\n", i, bootinfo->argv[i]);

	if (bootinfo->argc >= 3)
		freq = atoi(bootinfo->argv[2]);

	kputs("Reset SCC!\n");
	scc_clear();
	kputs("Wait some time...\n");
	mb();
	start = rdtsc();
	do {
		mb();
		end = rdtsc();
		ticks = end > start ? end - start : start - end;
	} while(ticks*TIMER_FREQ < 300ULL*freq*1000000ULL);

	if (RCCE_init(&bootinfo->argc, &bootinfo->argv) != RCCE_SUCCESS)
		return -ENODEV;
	if (iRCCE_init() != iRCCE_SUCCESS)
		return -ENODEV;

	// enable additional outputs	
	RCCE_debug_set(RCCE_DEBUG_ALL);

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

	RCCE_barrier(&RCCE_COMM_WORLD);

#if 0
	kputs("RCCE test...\t");
	if (my_ue == 0)
		msg = 0x4711;
	if (RCCE_bcast((char*) &msg, sizeof(msg), 0, RCCE_COMM_WORLD) == RCCE_SUCCESS)
		kprintf("successfull! (0x%x)\n", msg);
	else
		kprintf("failed! (0x%x)\n", msg);
#endif

#if 0
	char* str = RCCE_shmalloc(128);
	if (my_ue == 1) {
		memset(str, 0x00, 128);
		strcpy(str, "Hello RCCE_shmalloc\n");
	}
	RCCE_barrier(&RCCE_COMM_WORLD);
	kprintf("RCCE_shmalloc test: %s\n", str);
	RCCE_shfree(str);
#endif

	// reset INTR/LINT0 flag
	z = Z_PID(RC_COREID[my_ue]);
	tmp=ReadConfigReg(CRB_OWN + (z==0 ? GLCFG0 : GLCFG1));
	tmp &= ~2;
	SetConfigReg(CRB_OWN + (z==0 ? GLCFG0 : GLCFG1), tmp);

	// set interrupt handler (INTR/LINT0)
	irq_install_handler(124, intr_handler);


	// unmask interrupts
	volatile uint64_t* irq_mask = (volatile uint64_t*)(FPGA_BASE + IRQ_MASK + my_ue*8);
	*irq_mask &= 0;

	// reset interrupt reg
	volatile uint64_t* irq_reset = (volatile uint64_t*)(FPGA_BASE + IRQ_RESET + my_ue*8);
	*irq_reset = ~(0);

	// set remote interrupts to LINT 0
	volatile int* irq_config = (volatile int*)(FPGA_BASE + IRQ_CONFIG + my_ue*4);
	*irq_config = 0;

	volatile int* irq_status = (volatile int*)(FPGA_BASE + IRQ_STATUS + my_ue*8);

	kprintf( "irq_mask = %x\n", *irq_mask );
	kprintf( "irq_config = %x\n", *irq_config );
	kprintf( "status_reg = %x\n", *irq_status );
	kputs("Now, the SCC is initialized!\n");

	return 0;
}

int icc_send_irq(int ue)
{
	int tmp, x, y, z, addr;

	z = Z_PID(RC_COREID[ue]);
	x = X_PID(RC_COREID[ue]);
	y = Y_PID(RC_COREID[ue]);
	addr = CRB_ADDR(x,y) + (z==0 ? GLCFG0 : GLCFG1);

	// send interrupt to ue
	do {
		NOP1;
		tmp=ReadConfigReg(addr);
	} while(tmp & 2);
	tmp |= 2;
	SetConfigReg(addr, tmp);

	return 0;
}

int icc_halt(void)
{
	icc_mail_check(0);
	NOP1;
	
	//HALT;

	return 0;
}

#define ROUNDS 1000
#define CORE_A 0	 	// sender
#define CORE_B 1		// receiver 


int icc_send_gic_irq(int core_num) {
	volatile uint64_t* irq_request = (volatile uint64_t*)(FPGA_BASE+IRQ_REQUEST+my_ue*8);
	uint64_t bit_pos;
	
	// determine bit position and set according bit
	bit_pos = (1 << core_num);
	*irq_request = bit_pos;	
	
	return 0;
}

int icc_irq_ping() 
{
	if( my_ue == 2 ) return -1 ;
	icc_send_gic_irq(2);
	kprintf( "my_ue = %d\n", my_ue );
	kprintf( "sending irq to 1!\n");
	return 0;
}

static inline void icc_mail_check_tag(iRCCE_MAIL_HEADER* mail) {
	char* recv_buffer;

	switch( mail->tag ) {
	case iRCCE_ANYLENGTH:
		recv_buffer = (char*)kmalloc( mail->size );
		iRCCE_irecv(recv_buffer, mail->size, 
				mail->source, NULL );
		break;

	case PING_REQ:
		kprintf( "icc_mail_check_tag: ping_req\n" );
		iRCCE_mail_send(0, PING_RESP, 0, NULL, mail->source);
		break;

	default: 
		kprintf( "icc_mail_check_tag: uknown tag id %d\n", mail->tag );
		break;
	}

}

int icc_mail_ping( void )
{	
	uint32_t flags;
	uint64_t timer = 0;
	int i;
	int res;
	iRCCE_MAIL_HEADER* recv_header = NULL;

	/* leave function if not participating in pingpong */
	if( (my_ue != CORE_A) && (my_ue != CORE_B) ) return -1;

	kprintf( "my_ue = %d\n", my_ue );
	kprintf( "Hello from mail_ping ... \n" );
	kprintf( "rounds = %d\n", ROUNDS );


	// disable interrupts
	flags = irq_nested_disable();
	
	for( i=0; i<ROUNDS+1; ++i ) {
		/* senders part */
		if( my_ue == CORE_A ) {
			/* send ping request */ 
			iRCCE_mail_send(0, PING_REQ, 0, NULL, CORE_B);
	
			/* wait for response */
			do {
				res = iRCCE_mail_recv(&recv_header);
				if( res == iRCCE_SUCCESS ) {
					if( recv_header->source == CORE_B )
						break;
					iRCCE_mail_release(&recv_header);
				}
			} while( 1 );

			/* release mail */
			iRCCE_mail_release(&recv_header);
		}
		/* receivers part */
		else {
			/* wait for request */
			do {
				res = iRCCE_mail_recv(&recv_header);
				if( res == iRCCE_SUCCESS ) {
					if( recv_header->tag == PING_REQ )
						break;
					iRCCE_mail_release(&recv_header);
				}
			} while( 1 );

			/* send response */
			iRCCE_mail_send(0, PING_RESP, 0, NULL, recv_header->source);

			/* release mail */
			iRCCE_mail_release(&recv_header);
		}
		
		/* start timer in first round */
		if( i == 0 ) timer = rdtsc();

	}

	/* stop timer */
	timer = rdtsc() - timer;


	if( my_ue == CORE_A ) {
		kprintf( "timer = %ld\n", timer );
		kprintf( "mail_pingpong needs in average %d msec (%d ticks)!\n",
		timer/(2*ROUNDS*533), timer/(2*ROUNDS) );
	}

	irq_nested_enable(flags);

	return 0;
}


int icc_mail_ping_irq( void )
{
	/* return if not core A */
	if( my_ue != CORE_A ) return 0;
	uint32_t flags;
	uint64_t timer = 0;
	int rem_rank = CORE_B;
	int i;
	int res;
	iRCCE_MAIL_HEADER* recv_header = NULL;

	kprintf( "Hello from mail_ping_irq ... \n" );
	kprintf( "my_rank = %d\n", my_ue );
	kprintf( "rem_rank = %d\n", rem_rank );	
	kprintf( "rounds = %d\n", ROUNDS );
	
	// disable interrupts
	flags = irq_nested_disable();
	for( i=0; i<ROUNDS+1; ++i ) {
		/* send ping request */ 
		iRCCE_mail_send(0, PING_REQ, 0, NULL, rem_rank);

		/* send interrupt */
		icc_send_gic_irq(rem_rank);

		/* wait for response */
		do {
			res = iRCCE_mail_check(rem_rank);
		} while( res != iRCCE_SUCCESS );
		
		/* release mail */
		do {
			if( recv_header ) iRCCE_mail_release(&recv_header);
			res = iRCCE_mail_recv(&recv_header);
		} while( (recv_header->source != rem_rank) 
				&& (recv_header->tag == PING_RESP) );

		iRCCE_mail_release(&recv_header);

		/* start timer in first round */
		if( i == 0 ) timer = rdtsc();
		
	}

	/* stop timer */
	timer = rdtsc() - timer;

	kprintf( "timer = %ld\n", timer );
	kprintf( "mail_pingpong needs in average %d msec (%d ticks)!\n",
		timer/(2*ROUNDS*533), timer/(2*ROUNDS) );

	
	irq_nested_enable(flags);
	return 0;
}


int icc_mail_noise() {
	int j, res;
	int num_ranks = RCCE_num_ues();
	iRCCE_MAIL_HEADER* recv_mail = NULL;

	// leave function if not participating
	if( (my_ue == CORE_A)  /*|| (my_ue == CORE_B)*/ ) {
		return -1;
	}  
	
	kprintf( "Hello from icc_mail_noise: my_ue = %d\n", my_ue );
	
	for( ;; ) {
		/* send a mail to each UE */
		for( j=0; j<num_ranks; ++j ) {
			if( (j == CORE_A) /*|| (j == CORE_B)*/ ) 
				continue;
	
			/* recv mails */
			iRCCE_mail_check(iRCCE_MAILBOX_ALL);

			iRCCE_mail_send(0, 100, 0, NULL, j);
			res = iRCCE_mail_recv(&recv_mail);
			if( res == iRCCE_SUCCESS ) {
				icc_mail_check_tag(recv_mail);
				iRCCE_mail_release(&recv_mail);
			}


		}
	
		/* read some mails */
		for( res = iRCCE_mail_recv(&recv_mail), j=0; (res == iRCCE_SUCCESS) && (j<48); res = iRCCE_mail_recv(&recv_mail), ++j ) {
			icc_mail_check_tag(recv_mail);
			iRCCE_mail_release(&recv_mail);	
		}
	
	}

	return 0;
}

/* 
 * Routine to check mailboxes. If irq = 1 is passed only those boxes are checked that 
 * refere to the cores with set bit in status register.
 * 
 */

void icc_mail_check(int irq)
{
	iRCCE_MAIL_HEADER* header		= NULL;
	int source, i, res;
	volatile uint64_t* irq_status_reg	= NULL; 
	volatile uint64_t* irq_reset_reg 	= NULL;
	uint64_t irq_status			= 0;
	uint32_t flags;

	/* disable interrupts */	
	flags = irq_nested_disable();

	if( irq == 1 ) {

		kprintf( "hello from gic irq" );
		/* read status register */
		irq_status_reg = (volatile uint64_t*)(FPGA_BASE + IRQ_STATUS + my_ue*8);
		irq_status = *irq_status_reg;


		/* determine interrupt sources */
		irq_status >>= 6;	// shift emac bits

		for( source = 0; irq_status != 0; irq_status >>= 1, ++source ) {
			if( (irq_status & 0x1) != 0 ) {
				res = iRCCE_mail_check(source);
			} 
		} 


		/* reset status register */
		irq_reset_reg = (volatile uint64_t*)(FPGA_BASE + IRQ_RESET + my_ue*8);
		*irq_reset_reg = ~(0);
	}
	else {
		iRCCE_mail_check(iRCCE_MAILBOX_ALL);
	}

	/* empty mail queue */
	while( (res = iRCCE_mail_recv(&header)) == iRCCE_SUCCESS ) {
		icc_mail_check_tag(header);
		iRCCE_mail_release( &header );
	}
	
	/* enable interrupts */
	irq_nested_enable(flags);

}

#endif