/*-
 *   BSD LICENSE
 *
 *   Copyright (c) Intel Corporation.
 *   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 Intel Corporation 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 "nvme_internal.h"

struct nvme_driver g_nvme_driver = {
	.lock = NVME_MUTEX_INITIALIZER,
	.init_ctrlrs = TAILQ_HEAD_INITIALIZER(g_nvme_driver.init_ctrlrs),
	.attached_ctrlrs = TAILQ_HEAD_INITIALIZER(g_nvme_driver.attached_ctrlrs),
};

int32_t		spdk_nvme_retry_count;

static struct spdk_nvme_ctrlr *
nvme_attach(void *devhandle)
{
	struct spdk_nvme_ctrlr	*ctrlr;
	int			status;
	uint64_t		phys_addr = 0;

	ctrlr = nvme_malloc("nvme_ctrlr", sizeof(struct spdk_nvme_ctrlr),
			    64, &phys_addr);
	if (ctrlr == NULL) {
		nvme_printf(NULL, "could not allocate ctrlr\n");
		return NULL;
	}

	status = nvme_ctrlr_construct(ctrlr, devhandle);
	if (status != 0) {
		nvme_free(ctrlr);
		return NULL;
	}

	return ctrlr;
}

int
spdk_nvme_detach(struct spdk_nvme_ctrlr *ctrlr)
{
	struct nvme_driver	*driver = &g_nvme_driver;

	nvme_mutex_lock(&driver->lock);

	nvme_ctrlr_destruct(ctrlr);
	TAILQ_REMOVE(&g_nvme_driver.attached_ctrlrs, ctrlr, tailq);
	nvme_free(ctrlr);

	nvme_mutex_unlock(&driver->lock);
	return 0;
}

void
nvme_completion_poll_cb(void *arg, const struct spdk_nvme_cpl *cpl)
{
	struct nvme_completion_poll_status	*status = arg;

	/*
	 * Copy status into the argument passed by the caller, so that
	 *  the caller can check the status to determine if the
	 *  the request passed or failed.
	 */
	memcpy(&status->cpl, cpl, sizeof(*cpl));
	status->done = true;
}

size_t
spdk_nvme_request_size(void)
{
	return sizeof(struct nvme_request);
}

struct nvme_request *
nvme_allocate_request(const struct nvme_payload *payload, uint32_t payload_size,
		      spdk_nvme_cmd_cb cb_fn, void *cb_arg)
{
	struct nvme_request *req = NULL;

	nvme_alloc_request(&req);

	if (req == NULL) {
		return req;
	}

	/*
	 * Only memset up to (but not including) the children
	 *  TAILQ_ENTRY.  children, and following members, are
	 *  only used as part of I/O splitting so we avoid
	 *  memsetting them until it is actually needed.
	 *  They will be initialized in nvme_request_add_child()
	 *  if the request is split.
	 */
	memset(req, 0, offsetof(struct nvme_request, children));
	req->cb_fn = cb_fn;
	req->cb_arg = cb_arg;
	req->payload = *payload;
	req->payload_size = payload_size;

	return req;
}

struct nvme_request *
nvme_allocate_request_contig(void *buffer, uint32_t payload_size, spdk_nvme_cmd_cb cb_fn,
			     void *cb_arg)
{
	struct nvme_payload payload;

	payload.type = NVME_PAYLOAD_TYPE_CONTIG;
	payload.u.contig = buffer;

	return nvme_allocate_request(&payload, payload_size, cb_fn, cb_arg);
}

struct nvme_request *
nvme_allocate_request_null(spdk_nvme_cmd_cb cb_fn, void *cb_arg)
{
	return nvme_allocate_request_contig(NULL, 0, cb_fn, cb_arg);
}

void
nvme_free_request(struct nvme_request *req)
{
	nvme_assert(req != NULL, ("nvme_free_request(NULL)\n"));
	nvme_assert(req->num_children == 0, ("num_children != 0\n"));

	nvme_dealloc_request(req);
}

struct nvme_enum_ctx {
	spdk_nvme_probe_cb probe_cb;
	void *cb_ctx;
};

/* This function must only be called while holding g_nvme_driver.lock */
static int
nvme_enum_cb(void *ctx, struct spdk_pci_device *pci_dev)
{
	struct nvme_enum_ctx *enum_ctx = ctx;
	struct spdk_nvme_ctrlr *ctrlr;
	struct spdk_nvme_ctrlr_opts opts;

	/* Verify that this controller is not already attached */
	TAILQ_FOREACH(ctrlr, &g_nvme_driver.attached_ctrlrs, tailq) {
		/* NOTE: This assumes that the PCI abstraction layer will use the same device handle
		 *  across enumerations; we could compare by BDF instead if this is not true.
		 */
		if (pci_dev == ctrlr->devhandle) {
			return 0;
		}
	}

	spdk_nvme_ctrlr_opts_set_defaults(&opts);

	if (enum_ctx->probe_cb(enum_ctx->cb_ctx, pci_dev, &opts)) {
		ctrlr = nvme_attach(pci_dev);
		if (ctrlr == NULL) {
			nvme_printf(NULL, "nvme_attach() failed\n");
			return -1;
		}

		ctrlr->opts = opts;

		TAILQ_INSERT_TAIL(&g_nvme_driver.init_ctrlrs, ctrlr, tailq);
	}

	return 0;
}

int
spdk_nvme_probe(void *cb_ctx, spdk_nvme_probe_cb probe_cb, spdk_nvme_attach_cb attach_cb)
{
	int rc, start_rc;
	struct nvme_enum_ctx enum_ctx;
	struct spdk_nvme_ctrlr *ctrlr, *ctrlr_tmp;

	nvme_mutex_lock(&g_nvme_driver.lock);

	enum_ctx.probe_cb = probe_cb;
	enum_ctx.cb_ctx = cb_ctx;

	rc = nvme_pci_enumerate(nvme_enum_cb, &enum_ctx);
	/*
	 * Keep going even if one or more nvme_attach() calls failed,
	 *  but maintain the value of rc to signal errors when we return.
	 */

	/* Initialize all new controllers in the init_ctrlrs list in parallel. */
	while (!TAILQ_EMPTY(&g_nvme_driver.init_ctrlrs)) {
		TAILQ_FOREACH_SAFE(ctrlr, &g_nvme_driver.init_ctrlrs, tailq, ctrlr_tmp) {
			/* Drop the driver lock while calling nvme_ctrlr_process_init()
			 *  since it needs to acquire the driver lock internally when calling
			 *  nvme_ctrlr_start().
			 *
			 * TODO: Rethink the locking - maybe reset should take the lock so that start() and
			 *  the functions it calls (in particular nvme_ctrlr_set_num_qpairs())
			 *  can assume it is held.
			 */
			nvme_mutex_unlock(&g_nvme_driver.lock);
			start_rc = nvme_ctrlr_process_init(ctrlr);
			nvme_mutex_lock(&g_nvme_driver.lock);

			if (start_rc) {
				/* Controller failed to initialize. */
				TAILQ_REMOVE(&g_nvme_driver.init_ctrlrs, ctrlr, tailq);
				nvme_ctrlr_destruct(ctrlr);
				nvme_free(ctrlr);
				rc = -1;
				break;
			}

			if (ctrlr->state == NVME_CTRLR_STATE_READY) {
				/*
				 * Controller has been initialized.
				 *  Move it to the attached_ctrlrs list.
				 */
				TAILQ_REMOVE(&g_nvme_driver.init_ctrlrs, ctrlr, tailq);
				TAILQ_INSERT_TAIL(&g_nvme_driver.attached_ctrlrs, ctrlr, tailq);

				/*
				 * Unlock while calling attach_cb() so the user can call other functions
				 *  that may take the driver lock, like nvme_detach().
				 */
				nvme_mutex_unlock(&g_nvme_driver.lock);
				attach_cb(cb_ctx, ctrlr->devhandle, ctrlr, &ctrlr->opts);
				nvme_mutex_lock(&g_nvme_driver.lock);

				break;
			}
		}
	}

	nvme_mutex_unlock(&g_nvme_driver.lock);
	return rc;
}