/*-
 *   BSD LICENSE
 *
 *   Copyright (c) Eideticom Inc.
 *   All rights reserved.
 *
 *   Redistribution and use in source and binary forms, with or without
 *   modification, are permitted provided that the following conditions
 *   are met:
 *
 *     * Redistributions of source code must retain the above copyright
 *       notice, this list of conditions and the following disclaimer.
 *     * Redistributions in binary form must reproduce the above copyright
 *       notice, this list of conditions and the following disclaimer in
 *       the documentation and/or other materials provided with the
 *       distribution.
 *     * Neither the name of Eideticom Inc,  nor the names of its
 *       contributors may be used to endorse or promote products derived
 *       from this software without specific prior written permission.
 *
 *   THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
 *   "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
 *   LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
 *   A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
 *   OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
 *   SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
 *   LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
 *   DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
 *   THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
 *   (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
 *   OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
 */

#include "spdk/stdinc.h"

#include "spdk/env.h"
#include "spdk/nvme.h"

#define CMB_COPY_DELIM "-"
#define CMB_COPY_READ 0
#define CMB_COPY_WRITE 1

struct nvme_io {
	struct spdk_nvme_ctrlr *ctrlr;
	struct spdk_nvme_transport_id trid;
	struct spdk_nvme_qpair	*qpair;
	struct spdk_nvme_ns *ns;
	unsigned nsid;
	unsigned slba;
	unsigned nlbas;
	uint32_t lba_size;
	unsigned done;
};

struct cmb_t {
	struct spdk_nvme_transport_id trid;
	struct spdk_nvme_ctrlr *ctrlr;
};

struct config {
	struct nvme_io read;
	struct nvme_io write;
	struct cmb_t   cmb;
	size_t         copy_size;
};

static struct config g_config;

/* Namespaces index from 1. Return 0 to invoke an error */
static unsigned get_nsid(const struct spdk_nvme_transport_id *trid)
{
	if (!strcmp(trid->traddr, g_config.read.trid.traddr)) {
		return g_config.read.nsid;
	}
	if (!strcmp(trid->traddr, g_config.write.trid.traddr)) {
		return g_config.write.nsid;
	}
	return 0;
}

static int get_rw(const struct spdk_nvme_transport_id *trid)
{
	if (!strcmp(trid->traddr, g_config.read.trid.traddr)) {
		return CMB_COPY_READ;
	}
	if (!strcmp(trid->traddr, g_config.write.trid.traddr)) {
		return CMB_COPY_WRITE;
	}
	return -1;
}

static void
check_io(void *arg, const struct spdk_nvme_cpl *completion)
{
	int *rw = (unsigned *)arg;

	if (*rw == CMB_COPY_READ) {
		g_config.read.done = 1;
	} else {
		g_config.write.done = 1;
	}
}

static int
cmb_copy(void)
{
	int rc = 0, rw;
	void *buf;

	/* Allocate QPs for the read and write controllers */
	g_config.read.qpair = spdk_nvme_ctrlr_alloc_io_qpair(g_config.read.ctrlr, NULL, 0);
	g_config.write.qpair = spdk_nvme_ctrlr_alloc_io_qpair(g_config.write.ctrlr, NULL, 0);
	if (g_config.read.qpair == NULL || g_config.read.qpair == NULL) {
		printf("ERROR: spdk_nvme_ctrlr_alloc_io_qpair() failed\n");
		return -ENOMEM;
	}

	/* Allocate a buffer from our CMB */
	buf = spdk_nvme_ctrlr_alloc_cmb_io_buffer(g_config.cmb.ctrlr, g_config.copy_size);
	if (buf == NULL) {
		printf("ERROR: buffer allocation failed\n");
		printf("Are you sure %s has a valid CMB?\n",
		       g_config.cmb.trid.traddr);
		return -ENOMEM;
	}

	/* Clear the done flags */
	g_config.read.done = 0;
	g_config.write.done = 0;

	rw = CMB_COPY_READ;
	/* Do the read to the CMB IO buffer */
	rc = spdk_nvme_ns_cmd_read(g_config.read.ns, g_config.read.qpair, buf,
				   g_config.read.slba, g_config.read.nlbas,
				   check_io, &rw, 0);
	if (rc != 0) {
		fprintf(stderr, "starting read I/O failed\n");
		return -EIO;
	}
	while (!g_config.read.done) {
		spdk_nvme_qpair_process_completions(g_config.read.qpair, 0);
	}

	/* Do the write from the CMB IO buffer */
	rw = CMB_COPY_WRITE;
	rc = spdk_nvme_ns_cmd_write(g_config.write.ns, g_config.write.qpair, buf,
				    g_config.write.slba, g_config.write.nlbas,
				    check_io, &rw, 0);
	if (rc != 0) {
		fprintf(stderr, "starting write I/O failed\n");
		return -EIO;
	}
	while (!g_config.write.done) {
		spdk_nvme_qpair_process_completions(g_config.write.qpair, 0);
	}

	/* Clear the done flags */
	g_config.read.done = 0;
	g_config.write.done = 0;

	/* Free CMB buffer */
	spdk_nvme_ctrlr_free_cmb_io_buffer(g_config.cmb.ctrlr, buf,
					   g_config.copy_size);

	/* Free the queues */
	spdk_nvme_ctrlr_free_io_qpair(g_config.read.qpair);
	spdk_nvme_ctrlr_free_io_qpair(g_config.write.qpair);

	return rc;
}

static bool
probe_cb(void *cb_ctx, const struct spdk_nvme_transport_id *trid,
	 struct spdk_nvme_ctrlr_opts *opts)
{
	/* We will only attach to the read or write controller */
	if (strcmp(trid->traddr, g_config.read.trid.traddr) &&
	    strcmp(trid->traddr, g_config.write.trid.traddr)) {
		printf("%s - not probed %s!\n", __func__, trid->traddr);
		return 0;
	}

	printf("%s - probed %s!\n", __func__, trid->traddr);
	return 1;
}

static void
attach_cb(void *cb_ctx, const struct spdk_nvme_transport_id *trid,
	  struct spdk_nvme_ctrlr *ctrlr, const struct spdk_nvme_ctrlr_opts *opts)
{
	struct spdk_nvme_ns *ns;

	ns = spdk_nvme_ctrlr_get_ns(ctrlr, get_nsid(trid));
	if (ns == NULL) {
		fprintf(stderr, "Could not locate namespace %d on controller %s.\n",
			get_nsid(trid), trid->traddr);
		exit(-1);
	}
	if (get_rw(trid) == CMB_COPY_READ) {
		g_config.read.ctrlr    = ctrlr;
		g_config.read.ns       = ns;
		g_config.read.lba_size = spdk_nvme_ns_get_sector_size(ns);
	} else {
		g_config.write.ctrlr    = ctrlr;
		g_config.write.ns       = ns;
		g_config.write.lba_size = spdk_nvme_ns_get_sector_size(ns);
	}
	printf("%s - attached %s!\n", __func__, trid->traddr);

	return;
}

static void
usage(char *program_name)
{
	printf("%s options (all mandatory)", program_name);
	printf("\n");
	printf("\t[-r NVMe read parameters]\n");
	printf("\t[-w NVMe write parameters]\n");
	printf("\t[-c CMB to use for data buffers]\n");
	printf("\n");
	printf("Read/Write params:\n");
	printf("  <pci id>-<namespace>-<start LBA>-<number of LBAs>\n");
}

static void
parse(char *in, struct nvme_io *io)
{
	char *tok = NULL;

	tok = strtok(in, CMB_COPY_DELIM);
	if (tok == NULL) {
		goto err;
	}
	snprintf(&io->trid.traddr[0], SPDK_NVMF_TRADDR_MAX_LEN + 1,
		 "%s", tok);

	tok = strtok(NULL, CMB_COPY_DELIM);
	if (tok == NULL) {
		goto err;
	}
	io->nsid  = atoi(tok);

	tok = strtok(NULL, CMB_COPY_DELIM);
	if (tok == NULL) {
		goto err;
	}
	io->slba  = atoi(tok);

	tok = strtok(NULL, CMB_COPY_DELIM);
	if (tok == NULL) {
		goto err;
	}
	io->nlbas = atoi(tok);

	tok = strtok(NULL, CMB_COPY_DELIM);
	if (tok != NULL) {
		goto err;
	}
	return;

err:
	fprintf(stderr, "%s: error parsing %s\n", __func__, in);
	exit(-1);

}

static int
parse_args(int argc, char **argv)
{
	int op;
	unsigned read = 0, write = 0, cmb = 0;

	while ((op = getopt(argc, argv, "r:w:c:")) != -1) {
		switch (op) {
		case 'r':
			parse(optarg, &g_config.read);
			read = 1;
			break;
		case 'w':
			parse(optarg, &g_config.write);
			write = 1;
			break;
		case 'c':
			snprintf(g_config.cmb.trid.traddr, SPDK_NVMF_TRADDR_MAX_LEN + 1,
				 "%s", optarg);
			cmb = 1;
			break;
		default:
			usage(argv[0]);
			return 1;
		}
	}

	if ((!read || !write || !cmb)) {
		usage(argv[0]);
		return 1;
	}

	return 0;
}

int main(int argc, char **argv)
{
	int rc = 0;
	struct spdk_env_opts opts;

	/*
	 * Parse the input arguments. For now we use the following
	 * format list:
	 *
	 * <pci id>-<namespace>-<start LBA>-<number of LBAs>
	 *
	 */
	rc = parse_args(argc, argv);
	if (rc) {
		fprintf(stderr, "Error in parse_args(): %d\n",
			rc);
		return -1;
	}

	/*
	 * SPDK relies on an abstraction around the local environment
	 * named env that handles memory allocation and PCI device operations.
	 * This library must be initialized first.
	 *
	 */
	spdk_env_opts_init(&opts);
	opts.name = "cmb_copy";
	opts.shm_id = 0;
	if (spdk_env_init(&opts) < 0) {
		fprintf(stderr, "Unable to initialize SPDK env\n");
		return 1;
	}

	/*
	 * CMBs only apply to PCIe attached NVMe controllers so we
	 * only probe the PCIe bus. This is the default when we pass
	 * in NULL for the first argument.
	 */

	rc = spdk_nvme_probe(NULL, NULL, probe_cb, attach_cb, NULL);
	if (rc) {
		fprintf(stderr, "Error in spdk_nvme_probe(): %d\n",
			rc);
		return -1;
	}

	/*
	 * For now enforce that the read and write controller are not
	 * the same. This avoids an internal only DMA.
	 */
	if (!strcmp(g_config.write.trid.traddr, g_config.read.trid.traddr)) {
		fprintf(stderr, "Read and Write controllers must differ!\n");
		return -1;
	}

	/*
	 * Perform a few sanity checks and set the buffer size for the
	 * CMB.
	 */
	if (g_config.read.nlbas * g_config.read.lba_size !=
	    g_config.write.nlbas * g_config.write.lba_size) {
		fprintf(stderr, "Read and write sizes do not match!\n");
		return -1;
	}
	g_config.copy_size = g_config.read.nlbas * g_config.read.lba_size;

	/*
	 * Get the ctrlr pointer for the CMB. For now we assume this
	 * is either the read or write NVMe controller though in
	 * theory that is not a necessary condition.
	 */

	if (!strcmp(g_config.cmb.trid.traddr, g_config.read.trid.traddr)) {
		g_config.cmb.ctrlr = g_config.read.ctrlr;
	}
	if (!strcmp(g_config.cmb.trid.traddr, g_config.write.trid.traddr)) {
		g_config.cmb.ctrlr = g_config.write.ctrlr;
	}

	/*
	 * Call the cmb_copy() function which performs the CMB
	 * based copy or returns an error code if it fails.
	 */
	rc = cmb_copy();
	if (rc) {
		fprintf(stderr, "Error in spdk_cmb_copy(): %d\n",
			rc);
		return -1;
	}

	return rc;
}