/* unibus.cpp: utilities to handle UNIBUS functions

 Copyright (c) 2018, Joerg Hoppe
 j_hoppe@t-online.de, www.retrocmp.com

 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
 JOERG HOPPE 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.

 jul-2019     JH      rewrite: multiple parallel arbitration levels
 12-nov-2018  JH      entered beta phase
 */

#define _UNIBUS_CPP_

#include <stdio.h>
#include <string.h>
#include <stdint.h>
#include <stdbool.h>
#include <time.h>
#include <assert.h>

#include "pru.hpp"
#include "logger.hpp"
#include "gpios.hpp"
#include "bitcalc.h"
#include "memoryimage.hpp"
#include "mailbox.h" // for test of PRU code
#include "utils.hpp" // for test of PRU code
#include "unibusadapter.hpp" // DMA, INTR

#include "unibus.h"

/* Singleton */
unibus_c *unibus;

unibus_c::unibus_c() {
	log_label = "UNIBUS";
	dma_request = new dma_request_c(NULL);
	// priority backplane slot # for helper DMA not important, as typically used stand-alone
	// (no other devioces on the backplane active, except perhaps "testcontroller")
	dma_request->set_priority_slot(16);
}

unibus_c::~unibus_c() {
	delete dma_request;
}

/* return a 16 bit result, or TIMEOUT
 * result: 0 = timeout, else OK
 */
char *unibus_c::data2text(unsigned val) {
	static char buffer[256];
	if (val <= 0177777)
		sprintf(buffer, "%06o", val);
	else
		strcpy(buffer, "??????");
	return buffer;
}

/* return UNOBUS control as text: "DATI", DATO", ....
 */
char *unibus_c::control2text(uint8_t control) {
	static char buffer[256];
	switch (control) {
	case UNIBUS_CONTROL_DATI:
		strcpy(buffer, "DATI");
		break;
	case UNIBUS_CONTROL_DATIP:
		strcpy(buffer, "DATIP");
		break;
	case UNIBUS_CONTROL_DATO:
		strcpy(buffer, "DATO");
		break;
	case UNIBUS_CONTROL_DATOB:
		strcpy(buffer, "DATOB");
		break;
	default:
		strcpy(buffer, "???");
	}
	return buffer;
}

/* pulse INIT cycle for some milliseconds
 */
void unibus_c::init(unsigned pulsewidth_ms) {
	mailbox->initializationsignal.id = INITIALIZATIONSIGNAL_INIT;
	mailbox->initializationsignal.val = 1;
	mailbox_execute(ARM2PRU_INITALIZATIONSIGNAL_SET);
	timeout_c::wait_ms(pulsewidth_ms);
	mailbox->initializationsignal.id = INITIALIZATIONSIGNAL_INIT;
	mailbox->initializationsignal.val = 0;
	mailbox_execute(ARM2PRU_INITALIZATIONSIGNAL_SET);
}

// return: bitmask with shortcount BG*/NPG IN_OUT signals
// Values see PRIORITY_ARBITRATION_BIT_*
// Fiddling with the BG*/NPG signal may crash running CPU, also
// the M9302 will generate a SACK.
// So CPU is stopped with a surrounding a power cycle
uint8_t unibus_c::probe_grant_continuity(bool error_if_closed) {
	uint8_t grant_mask = 0;
	// simulate POWER OFF
	powercycle(1);
#if 0
	// CPU should be stopped now, holding BG*/NPG lines active LOW = logic 0.
	// If the power vector 24 does something weird, we may have
	// BG*/NPG set and have malfunctions now.

	// Test algorithm is difficult to implement.

	// First, pull INIT low to disable fucntion of other cards

	// 3 cases:
	// 	1) Running CPU on BUS: set a BR, wait for BGIN
	//	(not tested here)
	//
	// 2) If HALTed CPU on bus: BG*/NPG held LOW
	// Need M9302 with SACK turnaround.
	// 	- set each BGOUT/NPGOUT  (assume IN  0 by CPU)
	//  - if M9302 responds with SACK:
	//      it sees a BG 1 => no jumper IN-OUT
	//		if no SACK: M9302 sees a "0" => jumper set

	// 3) If no CPU on bus: BG*/NPG pulled up
	//     set BG OUT = 0, if IN 0 -> jumper!

	// Set BG*_OUT/NPG_OUT bits at latch 0
	// and read back
	mailbox->buslatch.addr = 0;
	mailbox->buslatch.bitmask = PRIORITY_ARBITRATION_BIT_MASK;
	mailbox->buslatch.val = 0x00; // output 0 = against pullups
	mailbox_execute(ARM2PRU_BUSLATCH_SET);

	// Read back BG*_IN/NPG_IN bits from latch 0
//	mailbox->buslatch.addr = 0;
//	mailbox_execute(ARM2PRU_BUSLATCH_GET);
	uint8_t grant_mask = ~ (mailbox->buslatch.val & PRIORITY_ARBITRATION_BIT_MASK);
#endif
	// simulate POWER ON
	powercycle(2);

	if (grant_mask && error_if_closed) {
		printf("Error: GRANT IN-OUT closed on UNIBUS backplane:");
		if (grant_mask & PRIORITY_ARBITRATION_BIT_B4)
			printf(" BG4");
		if (grant_mask & PRIORITY_ARBITRATION_BIT_B5)
			printf(" BG5");
		if (grant_mask & PRIORITY_ARBITRATION_BIT_B6)
			printf(" BG6");
		if (grant_mask & PRIORITY_ARBITRATION_BIT_B7)
			printf(" BG7");
		if (grant_mask & PRIORITY_ARBITRATION_BIT_NP)
			printf(" NPG");
		printf(".\n");
		exit(1);
	}

	return grant_mask;
}

/* Simulate a power cycle
 * Sequence: 
 * 1. Line power fail -> ACLO active
 * 2. Power supply capacitors empty -> DCLO active
 * 3. Line power back -> ACLO inactive
 * 4. Logic power OK -> DCLO inactive
 * phase: 0x01 = only OFF, 0x02 = only ON, 0x03 = ON and OFF
 */
void unibus_c::powercycle(int phase) {
	const unsigned delay_ms = 200; // time between phases
	if (phase & 0x01) {
		mailbox->initializationsignal.id = INITIALIZATIONSIGNAL_ACLO;
		mailbox->initializationsignal.val = 1;
		mailbox_execute(ARM2PRU_INITALIZATIONSIGNAL_SET);
		timeout_c::wait_ms(delay_ms);
		mailbox->initializationsignal.id = INITIALIZATIONSIGNAL_DCLO;
		mailbox->initializationsignal.val = 1;
		mailbox_execute(ARM2PRU_INITALIZATIONSIGNAL_SET);
		timeout_c::wait_ms(delay_ms);
	}
	if (phase & 0x02) {
		mailbox->initializationsignal.id = INITIALIZATIONSIGNAL_ACLO;
		mailbox->initializationsignal.val = 0;
		mailbox_execute(ARM2PRU_INITALIZATIONSIGNAL_SET);
		timeout_c::wait_ms(delay_ms);
		mailbox->initializationsignal.id = INITIALIZATIONSIGNAL_DCLO;
		mailbox->initializationsignal.val = 0;
		mailbox_execute(ARM2PRU_INITALIZATIONSIGNAL_SET);
		// wait for CPU to come up
		timeout_c::wait_ms(delay_ms);
	}
}

void unibus_c::set_arbitrator_active(bool active) {
	if (active) {
		mailbox_execute(ARM2PRU_ARB_MODE_CLIENT);
	} else {
		mailbox_execute(ARM2PRU_ARB_MODE_NONE);
	}
	arbitrator_active = active;
}

bool unibus_c::get_arbitrator_active(void) {
	return arbitrator_active;
}

// do a DMA transaction with or without arbitration (arbitration_client)
// mailbox.dma.words already filled
// if result = timeout: =
// 0 = bus time, error address =  mailbox->dma.cur_addr
// 1 = all transfered
// A limit for time used by DMA can be compiled-in
bool unibus_c::dma(bool blocking, uint8_t control, uint32_t startaddr, uint16_t *buffer,
		unsigned wordcount) {
	int dma_bandwidth_percent = 50; // use 50% of time for DMA, rest for running PDP-11 CPU
	uint64_t dmatime_ns, totaltime_ns;
	// can access bus with DMA when there's a Bus Arbitrator
	assert(pru->prucode_id == pru_c::PRUCODE_UNIBUS);

	timeout.start_ns(0); // no timeout, just running timer
	unibusadapter->DMA(*dma_request, blocking, control, startaddr, buffer, wordcount);

	dmatime_ns = timeout.elapsed_ns();
	// wait before next transaction, to reduce Unibus bandwidth
	// calc required total time for DMA time + wait
	// 100% -> total = dma
	// 50% -> total = 2*dma
	// 25% -> total = 4* dma
	totaltime_ns = (dmatime_ns * 100) / dma_bandwidth_percent;
	// whole transaction requires totaltime, dma already done
	timeout.wait_ns(totaltime_ns - dmatime_ns);

	return dma_request->success; // only useful if blocking
}

/* scan unibus addresses ascending from 0.
 * Stop on error, return first invalid address
 * return 0: no memory found at all
 * arbitration_active: if 1, perform NPR/NPG/SACK arbitration before mem accesses
 * words[]: buffer for whole UNIBUS address range, is filled with data
 */
uint32_t unibus_c::test_sizer(void) {
	// tests chunks of 128 word
	unsigned addr = 0;

	// one big transaction, automatically split in chunks
	unibusadapter->DMA(*dma_request, true, UNIBUS_CONTROL_DATI, addr, testwords,
	UNIBUS_WORDCOUNT);
	return dma_request->unibus_end_addr; // first non implemented address
}

/*
 * Test memory from 0 .. end_addr
 * mode = 1: fill every word with its address, then check endlessly,
 */

// write a subset of words[] with UNIBUS DMA:
// all words from start_addr to including end_addr
//
// DMA blocksize can be choosen arbitrarily
void unibus_c::mem_write(uint16_t *words, unsigned unibus_start_addr, unsigned unibus_end_addr,
bool *timeout) {
	unsigned wordcount = (unibus_end_addr - unibus_start_addr) / 2 + 1;
	uint16_t *buffer_start_addr = words + unibus_start_addr / 2;
	assert(pru->prucode_id == pru_c::PRUCODE_UNIBUS);
	*timeout = !dma(true, UNIBUS_CONTROL_DATO, unibus_start_addr, buffer_start_addr, wordcount);
	if (*timeout) {
		printf("\nWrite timeout @ 0%6o\n", mailbox->dma.cur_addr);
		return;
	}
}

// Read a subset of words[] with UNIBUS DMA
// all words from start_addr to including end_addr
// DMA blocksize can be choosen arbitrarily
// arbitration_active: if 1, perform NPR/NPG/SACK arbitration before mem accesses
void unibus_c::mem_read(uint16_t *words, uint32_t unibus_start_addr, uint32_t unibus_end_addr,
bool *timeout) {
	unsigned wordcount = (unibus_end_addr - unibus_start_addr) / 2 + 1;
	uint16_t *buffer_start_addr = words + unibus_start_addr / 2;
	assert(pru->prucode_id == pru_c::PRUCODE_UNIBUS);

	*timeout = !dma(true, UNIBUS_CONTROL_DATI, unibus_start_addr, buffer_start_addr, wordcount);
	if (*timeout) {
		printf("\nRead timeout @ 0%6o\n", mailbox->dma.cur_addr);
		return;
	}
}

// read or write
void unibus_c::mem_access_random(uint8_t unibus_control, uint16_t *words,
		uint32_t unibus_start_addr, uint32_t unibus_end_addr, bool *timeout,
		uint32_t *block_counter) {
	uint32_t block_unibus_start_addr, block_unibus_end_addr;
	// in average, make 16 sub transactions 
	assert(pru->prucode_id == pru_c::PRUCODE_UNIBUS);
	assert(unibus_control == UNIBUS_CONTROL_DATI || unibus_control == UNIBUS_CONTROL_DATO);
	block_unibus_start_addr = unibus_start_addr;
	// split transaction in random sized blocks
	uint32_t max_block_wordcount = (unibus_end_addr - unibus_start_addr + 2) / 2;

	do {
		uint16_t *block_buffer_start = words + block_unibus_start_addr / 2;
		uint32_t block_wordcount;
		do {
			block_wordcount = random32_log(max_block_wordcount);
		} while (block_wordcount < 1);
		assert(block_wordcount < max_block_wordcount);
		// wordcount limited by "words left to transfer"
		block_wordcount = std::min(block_wordcount,
				(unibus_end_addr - block_unibus_start_addr) / 2 + 1);
		block_unibus_end_addr = block_unibus_start_addr + 2 * block_wordcount - 2;
		assert(block_unibus_end_addr <= unibus_end_addr);
		(*block_counter) += 1;
		// printf("%06d: %5u words %06o-0%06o\n", *block_counter, block_wordcount, block_unibus_start_addr, block_unibus_end_addr) ;
		*timeout = !dma(true, unibus_control, block_unibus_start_addr, block_buffer_start,
				block_wordcount);
		if (*timeout) {
			printf("\n%s timeout @ 0%6o\n", control2text(unibus_control),
					mailbox->dma.cur_addr);
			return;
		}
		block_unibus_start_addr = block_unibus_end_addr + 2;
	} while (block_unibus_start_addr <= unibus_end_addr);
}

// arbitration_active: if 1, perform NPR/NPG/SACK arbitration before mem accesses
void unibus_c::test_mem(uint32_t start_addr, uint32_t end_addr, unsigned mode) {
#define MAX_ERROR_COUNT	8
	progress_c progress = progress_c(80);
	bool timeout = 0, mismatch = 0;
	unsigned mismatch_count = 0;
	uint32_t cur_test_addr;
	unsigned pass_count = 0, total_read_block_count = 0, total_write_block_count = 0;

	assert(pru->prucode_id == pru_c::PRUCODE_UNIBUS);

	// Setup ^C catcher
	SIGINTcatchnext();
	switch (mode) {
	case 1: // single write, multiple read, "address" pattern
		/**** 1. Generate test values: only for even addresses */
		for (cur_test_addr = start_addr; cur_test_addr <= end_addr; cur_test_addr += 2)
			testwords[cur_test_addr / 2] = (cur_test_addr >> 1) & 0xffff;
		/**** 2. Write memory ****/
		progress.put("W");  //info : full memory write
		mem_write(testwords, start_addr, end_addr, &timeout);

		/**** 3. read until ^C ****/
		while (!SIGINTreceived && !timeout && !mismatch_count) {
			pass_count++;
			if (pass_count % 10 == 0)
				progress.putf(" %d ", pass_count);
			total_write_block_count++; // not randomized
			total_read_block_count++;
			progress.put("R");
			// read back into unibus_membuffer[]
			mem_read(membuffer->data.words, start_addr, end_addr, &timeout);
			// compare
			for (mismatch_count = 0, cur_test_addr = start_addr; cur_test_addr <= end_addr;
					cur_test_addr += 2) {
				uint16_t cur_mem_val = membuffer->data.words[cur_test_addr / 2];
				mismatch = (testwords[cur_test_addr / 2] != cur_mem_val);
				if (mismatch && ++mismatch_count <= MAX_ERROR_COUNT) // print only first errors
					printf(
							"\nMemory mismatch #%d at %06o: expected %06o, found %06o, diff mask = %06o.  ",
							mismatch_count, cur_test_addr, testwords[cur_test_addr / 2],
							cur_mem_val, testwords[cur_test_addr / 2] ^ cur_mem_val);
			}
		} // while
		break;

	case 2: // full write, full read
		/**** 1. Full write generate test values */
//		start_addr = 0;
//		end_addr = 076;
		while (!SIGINTreceived && !timeout && !mismatch_count) {
			pass_count++;
			if (pass_count % 10 == 0)
				progress.putf(" %d ", pass_count);

			for (cur_test_addr = start_addr; cur_test_addr <= end_addr; cur_test_addr += 2)
				testwords[cur_test_addr / 2] = random24() & 0xffff; // random
//				testwords[cur_test_addr / 2] = (cur_test_addr >> 1) & 0xffff; // linear

			progress.put("W");  //info : full memory write
			mem_access_random(UNIBUS_CONTROL_DATO, testwords, start_addr, end_addr, &timeout,
					&total_write_block_count);

			if (SIGINTreceived || timeout)
				break; // leave loop

			// first full read
			progress.put("R");  //info : full memory write
			// read back into unibus_membuffer[]
			mem_access_random(UNIBUS_CONTROL_DATI, membuffer->data.words, start_addr, end_addr,
					&timeout, &total_read_block_count);
			// compare
			for (mismatch_count = 0, cur_test_addr = start_addr; cur_test_addr <= end_addr;
					cur_test_addr += 2) {
				uint16_t cur_mem_val = membuffer->data.words[cur_test_addr / 2];
				mismatch = (testwords[cur_test_addr / 2] != cur_mem_val);
				if (mismatch && ++mismatch_count <= MAX_ERROR_COUNT) // print only first errors
					printf(
							"\nMemory mismatch at %06o: expected %06o, found %06o, diff mask = %06o.  ",
							cur_test_addr, testwords[cur_test_addr / 2], cur_mem_val,
							testwords[cur_test_addr / 2] ^ cur_mem_val);
			}
		} // while
		break;
	} // switch(mode)
	printf("\n");
	if (timeout || mismatch_count)
		printf("Stopped by error: %stimeout, %d mismatches\n", (timeout ? "" : "no "),
				mismatch_count);
	else
		printf("All OK! Total %d passes, split into %d block writes and %d block reads\n",
				pass_count, total_write_block_count, total_read_block_count);
}