#define _PCILIB_DMA_IPE_C
#define _BSD_SOURCE

#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include <unistd.h>
#include <sys/time.h>
#include <arpa/inet.h>

#include "pci.h"
#include "pcilib.h"
#include "error.h"
#include "tools.h"

#include "ipe.h"
#include "ipe_private.h"
#include "ipe_registers.h"


#define WR(addr, value) { *(uint32_t*)(ctx->base_addr + addr) = value; }
#define RD(addr, value) { value = *(uint32_t*)(ctx->base_addr + addr); }


pcilib_dma_context_t *dma_ipe_init(pcilib_t *pcilib, pcilib_dma_modification_t type, void *arg) {
    int err = 0;
    
    pcilib_model_description_t *model_info = pcilib_get_model_description(pcilib);

    ipe_dma_t *ctx = malloc(sizeof(ipe_dma_t));

    if (ctx) {
	memset(ctx, 0, sizeof(ipe_dma_t));
	ctx->pcilib = pcilib;
//	ctx->mode64 = 1;
	
	memset(ctx->engine, 0, 2 * sizeof(pcilib_dma_engine_description_t));
	ctx->engine[0].addr = 0;
	ctx->engine[0].type = PCILIB_DMA_TYPE_PACKET;
	ctx->engine[0].direction = PCILIB_DMA_FROM_DEVICE;
	ctx->engine[0].addr_bits = 32;
	pcilib_set_dma_engine_description(pcilib, 0, &ctx->engine[0]);
	pcilib_set_dma_engine_description(pcilib, 1, NULL);

	pcilib_register_bank_t dma_bank = pcilib_find_bank_by_addr(pcilib, PCILIB_REGISTER_BANK_DMA);
	if (dma_bank == PCILIB_REGISTER_BANK_INVALID) {
	    free(ctx);
	    pcilib_error("DMA Register Bank could not be found");
	    return NULL;
	}

	ctx->dma_bank = model_info->banks + dma_bank;
	ctx->base_addr = pcilib_resolve_register_address(pcilib, ctx->dma_bank->bar, ctx->dma_bank->read_addr);

	err = pcilib_add_registers(ctx->pcilib, 0, ipe_dma_registers);
	if (err) {
	    free(ctx);
	    pcilib_error("Error adding DMA registers");
	    return NULL;
	}
    }

    return (pcilib_dma_context_t*)ctx;
}

void  dma_ipe_free(pcilib_dma_context_t *vctx) {
    ipe_dma_t *ctx = (ipe_dma_t*)vctx;

    if (ctx) {
	dma_ipe_stop(vctx, PCILIB_DMA_ENGINE_ALL, PCILIB_DMA_FLAGS_DEFAULT);
	free(ctx);
    }
}


int dma_ipe_start(pcilib_dma_context_t *vctx, pcilib_dma_engine_t dma, pcilib_dma_flags_t flags) {
    size_t i;

    ipe_dma_t *ctx = (ipe_dma_t*)vctx;

    int preserve = 0;
    pcilib_kmem_flags_t kflags;
    pcilib_kmem_reuse_state_t reuse_desc, reuse_pages;

    volatile void *desc_va;
    volatile uint32_t *last_written_addr_ptr;

    pcilib_register_value_t value;
    
    uint32_t address64;
    

    if (dma == PCILIB_DMA_ENGINE_INVALID) return 0;
    else if (dma > 1) return PCILIB_ERROR_INVALID_BANK;

    if (!ctx->started) ctx->started = 1;

    if (flags&PCILIB_DMA_FLAG_PERSISTENT) ctx->preserve = 1;

    if (ctx->pages) return 0;
    
    kflags = PCILIB_KMEM_FLAG_REUSE|PCILIB_KMEM_FLAG_EXCLUSIVE|PCILIB_KMEM_FLAG_HARDWARE|(ctx->preserve?PCILIB_KMEM_FLAG_PERSISTENT:0);
    pcilib_kmem_handle_t *desc = pcilib_alloc_kernel_memory(ctx->pcilib, PCILIB_KMEM_TYPE_CONSISTENT, 1, IPEDMA_DESCRIPTOR_SIZE, IPEDMA_DESCRIPTOR_ALIGNMENT, PCILIB_KMEM_USE(PCILIB_KMEM_USE_DMA_RING, 0x00), kflags);
    pcilib_kmem_handle_t *pages = pcilib_alloc_kernel_memory(ctx->pcilib, PCILIB_KMEM_TYPE_DMA_C2S_PAGE, IPEDMA_DMA_PAGES, 0, 0, PCILIB_KMEM_USE(PCILIB_KMEM_USE_DMA_PAGES, 0x00), kflags);

    if (!desc||!pages) {
	if (pages) pcilib_free_kernel_memory(ctx->pcilib, pages, 0);
	if (desc) pcilib_free_kernel_memory(ctx->pcilib, desc, 0);
	return PCILIB_ERROR_MEMORY;
    }
    reuse_desc = pcilib_kmem_is_reused(ctx->pcilib, desc);
    reuse_pages = pcilib_kmem_is_reused(ctx->pcilib, pages);

    if (reuse_desc == reuse_pages) {
	if (reuse_desc & PCILIB_KMEM_REUSE_PARTIAL) pcilib_warning("Inconsistent DMA buffers are found (only part of required buffers is available), reinitializing...");
	else if (reuse_desc & PCILIB_KMEM_REUSE_REUSED) {
	    if ((reuse_desc & PCILIB_KMEM_REUSE_PERSISTENT) == 0) pcilib_warning("Lost DMA buffers are found (non-persistent mode), reinitializing...");
	    else if ((reuse_desc & PCILIB_KMEM_REUSE_HARDWARE) == 0) pcilib_warning("Lost DMA buffers are found (missing HW reference), reinitializing...");
	    else {
#ifndef IPEDMA_BUG_DMARD
		RD(IPEDMA_REG_PAGE_COUNT, value);

		if (value != IPEDMA_DMA_PAGES) pcilib_warning("Inconsistent DMA buffers are found (Number of allocated buffers (%lu) does not match current request (%lu)), reinitializing...", value + 1, IPEDMA_DMA_PAGES);
		else
#endif /* IPEDMA_BUG_DMARD */
		    preserve = 1;
	    }
	}
    } else pcilib_warning("Inconsistent DMA buffers (modes of ring and page buffers does not match), reinitializing....");

    desc_va = pcilib_kmem_get_ua(ctx->pcilib, desc);
    if (ctx->mode64) last_written_addr_ptr = desc_va + 3 * sizeof(uint32_t);
    else last_written_addr_ptr = desc_va + 4 * sizeof(uint32_t);

    if (preserve) {
	ctx->reused = 1;
	ctx->preserve = 1;
	

//	usleep(100000);

	    // Detect the current state of DMA engine
#ifdef IPEDMA_BUG_DMARD
	FILE *f = fopen("/tmp/pcitool_lastread", "r");
	if (!f) pcilib_error("Can't read current status");
	fread(&value, 1, sizeof(pcilib_register_value_t), f);
	fclose(f);
#else /* IPEDMA_BUG_DMARD */
	RD(IPEDMA_REG_LAST_READ, value);
	    // Numbered from 1 in FPGA
	value--;
#endif /* IPEDMA_BUG_DMARD */

	ctx->last_read = value;
    } else {
	ctx->reused = 0;

	    // Disable DMA
	WR(IPEDMA_REG_CONTROL, 0x0);
	usleep(100000);
	
	    // Reset DMA engine
	WR(IPEDMA_REG_RESET, 0x1);
	usleep(100000);
	WR(IPEDMA_REG_RESET, 0x0);
	usleep(100000);

#ifndef IPEDMA_BUG_DMARD
	    // Verify PCIe link status
	RD(IPEDMA_REG_RESET, value);
	if (value != 0x14031700) pcilib_warning("PCIe is not ready, code is %lx", value);
#endif /* IPEDMA_BUG_DMARD */

	    // Enable 64 bit addressing and configure TLP and PACKET sizes (40 bit mode can be used with big pre-allocated buffers later)
	if (ctx->mode64) address64 = 0x8000 | (0<<24);
	else address64 = 0;
	
        WR(IPEDMA_REG_TLP_SIZE,  address64 | IPEDMA_TLP_SIZE);
        WR(IPEDMA_REG_TLP_COUNT, IPEDMA_PAGE_SIZE / (4 * IPEDMA_TLP_SIZE * IPEDMA_CORES));

	    // Setting progress register threshold
	WR(IPEDMA_REG_UPDATE_THRESHOLD, IPEDMA_DMA_PROGRESS_THRESHOLD);
        
	    // Reseting configured DMA pages
        WR(IPEDMA_REG_PAGE_COUNT, 0);
        
	    // Setting current read position and configuring progress register
	WR(IPEDMA_REG_LAST_READ, IPEDMA_DMA_PAGES);
	WR(IPEDMA_REG_UPDATE_ADDR, pcilib_kmem_get_block_ba(ctx->pcilib, desc, 0));

	    // Instructing DMA engine that writting should start from the first DMA page
	*last_written_addr_ptr = 0;//htonl(pcilib_kmem_get_block_ba(ctx->pcilib, pages, IPEDMA_DMA_PAGES - 1));

	
	for (i = 0; i < IPEDMA_DMA_PAGES; i++) {
	    uintptr_t bus_addr_check, bus_addr = pcilib_kmem_get_block_ba(ctx->pcilib, pages, i);
	    WR(IPEDMA_REG_PAGE_ADDR, bus_addr);
	    if (bus_addr%4096) printf("Bad address %lu: %lx\n", i, bus_addr);
	    
	    RD(IPEDMA_REG_PAGE_ADDR, bus_addr_check);
	    if (bus_addr_check != bus_addr) {
		pcilib_error("Written (%x) and read (%x) bus addresses does not match\n", bus_addr, bus_addr_check);
	    }
	    
	    usleep(1000);
	}
	
	    // Enable DMA
	WR(IPEDMA_REG_CONTROL, 0x1);
	
	ctx->last_read = IPEDMA_DMA_PAGES - 1;

#ifdef IPEDMA_BUG_DMARD
	FILE *f = fopen("/tmp/pcitool_lastread", "w");
	if (!f) pcilib_error("Can't write current status");
	value = ctx->last_read;
	fwrite(&value, 1, sizeof(pcilib_register_value_t), f);
	fclose(f);
#endif /* IPEDMA_BUG_DMARD */
    }

//    ctx->last_read_addr = htonl(pcilib_kmem_get_block_ba(ctx->pcilib, pages, ctx->last_read));
    ctx->last_read_addr = pcilib_kmem_get_block_ba(ctx->pcilib, pages, ctx->last_read);


    ctx->desc = desc;
    ctx->pages = pages;
    ctx->page_size = pcilib_kmem_get_block_size(ctx->pcilib, pages, 0);;
    ctx->ring_size = IPEDMA_DMA_PAGES;

    return 0;
}

int dma_ipe_stop(pcilib_dma_context_t *vctx, pcilib_dma_engine_t dma, pcilib_dma_flags_t flags) {
    pcilib_kmem_flags_t kflags;

    ipe_dma_t *ctx = (ipe_dma_t*)vctx;

    if (!ctx->started) return 0;

    if ((dma != PCILIB_DMA_ENGINE_INVALID)&&(dma > 1)) return PCILIB_ERROR_INVALID_BANK;

	    // ignoring previous setting if flag specified
    if (flags&PCILIB_DMA_FLAG_PERSISTENT) {
	ctx->preserve = 0;
    }

    if (ctx->preserve) {
	kflags = PCILIB_KMEM_FLAG_REUSE;
    } else {
        kflags = PCILIB_KMEM_FLAG_HARDWARE|PCILIB_KMEM_FLAG_PERSISTENT;

	ctx->started  = 0;

	    // Disable DMA
	WR(IPEDMA_REG_CONTROL, 0);
	usleep(100000);
	
	    // Reset DMA engine
	WR(IPEDMA_REG_RESET, 0x1);
	usleep(100000);
	WR(IPEDMA_REG_RESET, 0x0);
	usleep(100000);

	    // Reseting configured DMA pages
        WR(IPEDMA_REG_PAGE_COUNT, 0);
	usleep(100000);
    }

	// Clean buffers
    if (ctx->desc) {
	pcilib_free_kernel_memory(ctx->pcilib, ctx->desc, kflags);
	ctx->desc = NULL;
    }

    if (ctx->pages) {
	pcilib_free_kernel_memory(ctx->pcilib, ctx->pages, kflags);
	ctx->pages = NULL;
    }

    return 0;
}


int dma_ipe_get_status(pcilib_dma_context_t *vctx, pcilib_dma_engine_t dma, pcilib_dma_engine_status_t *status, size_t n_buffers, pcilib_dma_buffer_status_t *buffers) {
    size_t i;
    ipe_dma_t *ctx = (ipe_dma_t*)vctx;

    void *desc_va = (void*)pcilib_kmem_get_ua(ctx->pcilib, ctx->desc);
    uint32_t *last_written_addr_ptr;
    uint32_t last_written_addr;

    if (!status) return -1;

    if (ctx->mode64) last_written_addr_ptr = desc_va + 3 * sizeof(uint32_t);
    else last_written_addr_ptr = desc_va + 4 * sizeof(uint32_t);

    last_written_addr = *last_written_addr_ptr;

    status->started = ctx->started;
    status->ring_size = ctx->ring_size;
    status->buffer_size = ctx->page_size;

	// For simplicity, we keep last_read here, and fix in the end
    status->ring_tail = ctx->last_read;

	// Find where the ring head is actually are
    for (i = 0; i < ctx->ring_size; i++) {
	uintptr_t bus_addr = pcilib_kmem_get_block_ba(ctx->pcilib, ctx->pages, i);

	if (bus_addr == last_written_addr) {
	    status->ring_head = i;
	    break;
	}
    }

    if (i == ctx->ring_size) {
	if (last_written_addr) {
	    pcilib_warning("DMA is in unknown state, last_written_addr does not correspond any of available buffers");
	    return -1;
	}
	status->ring_head = 0;
	status->ring_tail = 0;
    }

    if (n_buffers > ctx->ring_size) n_buffers = ctx->ring_size;

    if (buffers) {
	memset(buffers, 0, n_buffers * sizeof(pcilib_dma_buffer_status_t));
	if (status->ring_head >= status->ring_tail) {
	    for (i = status->ring_tail + 1; (i <= status->ring_head)&&(i < n_buffers); i++) {
		buffers[i].used = 1;
		buffers[i].size = ctx->page_size;
		buffers[i].first = 1;
		buffers[i].last = 1;
	    }
	} else {
	    for (i = 0; (i <= status->ring_head)&&(i < n_buffers); i++) {
		buffers[i].used = 1;
		buffers[i].size = ctx->page_size;
		buffers[i].first = 1;
		buffers[i].last = 1;
	    } 

	    for (i = status->ring_tail + 1; (i < status->ring_size)&&(i < n_buffers); i++) {
		buffers[i].used = 1;
		buffers[i].size = ctx->page_size;
		buffers[i].first = 1;
		buffers[i].last = 1;
	    }
	}
    }

	// We actually keep last_read in the ring_tail, so need to increase
    if (status->ring_tail != status->ring_head) {
	status->ring_tail++;
	if (status->ring_tail == status->ring_size) status->ring_tail = 0;
    }

    return 0;
}

int dma_ipe_stream_read(pcilib_dma_context_t *vctx, pcilib_dma_engine_t dma, uintptr_t addr, size_t size, pcilib_dma_flags_t flags, pcilib_timeout_t timeout, pcilib_dma_callback_t cb, void *cbattr) {
    int err, ret = PCILIB_STREAMING_REQ_PACKET;


    pcilib_timeout_t wait = 0;
    struct timeval start, cur;

    volatile void *desc_va;
    volatile uint32_t *last_written_addr_ptr;
    volatile uint32_t *empty_detected_ptr;

    pcilib_dma_flags_t packet_flags = PCILIB_DMA_FLAG_EOP;

#ifdef IPEDMA_BUG_DMARD
    pcilib_register_value_t value;
#endif /* IPEDMA_BUG_DMARD */

    size_t cur_read;

    ipe_dma_t *ctx = (ipe_dma_t*)vctx;

    err = dma_ipe_start(vctx, dma, PCILIB_DMA_FLAGS_DEFAULT);
    if (err) return err;

    desc_va = (void*)pcilib_kmem_get_ua(ctx->pcilib, ctx->desc);

    if (ctx->mode64) last_written_addr_ptr = desc_va + 3 * sizeof(uint32_t);
    else last_written_addr_ptr = desc_va + 4 * sizeof(uint32_t);

    empty_detected_ptr = last_written_addr_ptr - 2;

    do {
	switch (ret&PCILIB_STREAMING_TIMEOUT_MASK) {
	    case PCILIB_STREAMING_CONTINUE: 
		    // Hardware indicates that there is no more data pending and we can safely stop if there is no data in the kernel buffers already
#ifdef IPEDMA_SUPPORT_EMPTY_DETECTED
		if (*empty_detected_ptr)
		    wait = 0;
		else
#endif /* IPEDMA_SUPPORT_EMPTY_DETECTED */
		    wait = IPEDMA_DMA_TIMEOUT; 
	    break;
	    case PCILIB_STREAMING_WAIT: 
		wait = (timeout > IPEDMA_DMA_TIMEOUT)?timeout:IPEDMA_DMA_TIMEOUT;
	    break;
//	    case PCILIB_STREAMING_CHECK: wait = 0; break;
	}

#ifdef IPEDMA_DEBUG
	printf("Waiting for data: %u (last read) 0x%x (last read addr) 0x%x (last_written)\n", ctx->last_read, ctx->last_read_addr, *last_written_addr_ptr);
#endif /* IPEDMA_DEBUG */

	gettimeofday(&start, NULL);
	memcpy(&cur, &start, sizeof(struct timeval));
	while (((*last_written_addr_ptr == 0)||(ctx->last_read_addr == (*last_written_addr_ptr)))&&((wait == PCILIB_TIMEOUT_INFINITE)||(((cur.tv_sec - start.tv_sec)*1000000 + (cur.tv_usec - start.tv_usec)) < wait))) {
	    usleep(10);
#ifdef IPEDMA_SUPPORT_EMPTY_DETECTED
	    if ((ret != PCILIB_STREAMING_REQ_PACKET)&&(*empty_detected_ptr)) break;
#endif /* IPEDMA_SUPPORT_EMPTY_DETECTED */
	    gettimeofday(&cur, NULL);
	}
	
	    // Failing out if we exited on timeout
	if ((ctx->last_read_addr == (*last_written_addr_ptr))||(*last_written_addr_ptr == 0)) {
#ifdef IPEDMA_SUPPORT_EMPTY_DETECTED
# ifdef IPEDMA_DEBUG
	    if ((wait)&&(*last_written_addr_ptr)&&(!*empty_detected_ptr))
		pcilib_warning("The empty_detected flag is not set, but no data arrived within %lu us\n", wait);
# endif /* IPEDMA_DEBUG */
#endif /* IPEDMA_SUPPORT_EMPTY_DETECTED */
	    return (ret&PCILIB_STREAMING_FAIL)?PCILIB_ERROR_TIMEOUT:0;
	}

	    // Getting next page to read
	cur_read = ctx->last_read + 1;
	if (cur_read == ctx->ring_size) cur_read = 0;

#ifdef IPEDMA_DEBUG
	printf("Reading: %u (last read) 0x%x (last read addr) 0x%x (last_written)\n", cur_read, ctx->last_read_addr, *last_written_addr_ptr);
#endif /* IPEDMA_DEBUG */

#ifdef IPEDMA_DETECT_PACKETS
	if ((*empty_detected_ptr)&&(pcilib_kmem_get_block_ba(ctx->pcilib, ctx->pages, cur_read) == (*last_written_addr_ptr))) packet_flags = PCILIB_DMA_FLAG_EOP;
	else packet_flags = 0;
#endif /* IPEDMA_DETECT_PACKETS */
	
	pcilib_kmem_sync_block(ctx->pcilib, ctx->pages, PCILIB_KMEM_SYNC_FROMDEVICE, cur_read);
        void *buf = pcilib_kmem_get_block_ua(ctx->pcilib, ctx->pages, cur_read);
	ret = cb(cbattr, packet_flags, ctx->page_size, buf);
	if (ret < 0) return -ret;
	
//	DS: Fixme, it looks like we can avoid calling this for the sake of performance
//	pcilib_kmem_sync_block(ctx->pcilib, ctx->pages, PCILIB_KMEM_SYNC_TODEVICE, cur_read);

	    // Numbered from 1
	WR(IPEDMA_REG_LAST_READ, cur_read + 1);

	ctx->last_read = cur_read;
//	ctx->last_read_addr = htonl(pcilib_kmem_get_block_ba(ctx->pcilib, ctx->pages, cur_read));
	ctx->last_read_addr = pcilib_kmem_get_block_ba(ctx->pcilib, ctx->pages, cur_read);

#ifdef IPEDMA_BUG_DMARD
	FILE *f = fopen("/tmp/pcitool_lastread", "w");
	if (!f) pcilib_error("Can't write current status");
	value = cur_read;
	fwrite(&value, 1, sizeof(pcilib_register_value_t), f);
	fclose(f);
#endif /* IPEDMA_BUG_DMARD */

    } while (ret);

    return 0;
}

double dma_ipe_benchmark(pcilib_dma_context_t *vctx, pcilib_dma_engine_addr_t dma, uintptr_t addr, size_t size, size_t iterations, pcilib_dma_direction_t direction) {
    int err = 0;

    ipe_dma_t *ctx = (ipe_dma_t*)vctx;

    int iter;
    size_t us = 0;
    struct timeval start, cur;
    
    void *buf;
    size_t bytes, rbytes;

    if ((direction == PCILIB_DMA_TO_DEVICE)||(direction == PCILIB_DMA_BIDIRECTIONAL)) return -1.;

    if ((dma != PCILIB_DMA_ENGINE_INVALID)&&(dma > 1)) return -1.;

    err = dma_ipe_start(vctx, 0, PCILIB_DMA_FLAGS_DEFAULT);
    if (err) return err;

    WR(IPEDMA_REG_CONTROL, 0x0);

    err = pcilib_skip_dma(ctx->pcilib, 0);
    if (err) {
	pcilib_error("Can't start benchmark, devices continuously writes unexpected data using DMA engine");
	return -1;
    }

    if (size%IPEDMA_PAGE_SIZE) size = (1 + size / IPEDMA_PAGE_SIZE) * IPEDMA_PAGE_SIZE;

	// Allocate memory and prepare data
    buf = malloc(size);
    if (!buf) return -1;

    for (iter = 0; iter < iterations; iter++) {
	gettimeofday(&start, NULL);

	    // Starting DMA
	WR(IPEDMA_REG_CONTROL, 0x1);
	
	for (bytes = 0; bytes < size; bytes += rbytes) {
	    err = pcilib_read_dma(ctx->pcilib, 0, addr, size - bytes, buf + bytes, &rbytes);
	    if (err) {
		pcilib_error("Can't read data from DMA, error %i", err);
	        return -1;
	    }
	}

	    // Stopping DMA
	WR(IPEDMA_REG_CONTROL, 0x0);
	if (err) break;
	
	gettimeofday(&cur, NULL);
	us += ((cur.tv_sec - start.tv_sec)*1000000 + (cur.tv_usec - start.tv_usec));
	    
	err = pcilib_skip_dma(ctx->pcilib, 0);
	if (err) {
	    pcilib_error("Can't start iteration, devices continuously writes unexpected data using DMA engine");
	    break;
	}
    }

    free(buf);

    return err?-1:((1. * size * iterations * 1000000) / (1024. * 1024. * us));
}