/*-
 *   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,
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 *   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.
 */

/* VFIO transport extensions for spdk_nvme_ctrlr */

#include "spdk/stdinc.h"
#include "spdk/env.h"
#include "spdk/likely.h"
#include "spdk/string.h"
#include "spdk/vfio_user_pci.h"
#include "nvme_internal.h"
#include "nvme_pcie_internal.h"

#include <linux/vfio.h>

#define NVME_MAX_XFER_SIZE		(131072)
#define NVME_MAX_SGES			(1)

struct nvme_vfio_ctrlr {
	struct nvme_pcie_ctrlr pctrlr;

	volatile uint32_t *doorbell_base;
	int bar0_fd;
	struct vfio_device *dev;
};

static inline struct nvme_vfio_ctrlr *
nvme_vfio_ctrlr(struct spdk_nvme_ctrlr *ctrlr)
{
	struct nvme_pcie_ctrlr *pctrlr = nvme_pcie_ctrlr(ctrlr);

	return SPDK_CONTAINEROF(pctrlr, struct nvme_vfio_ctrlr, pctrlr);
}

static int
nvme_vfio_ctrlr_set_reg_4(struct spdk_nvme_ctrlr *ctrlr, uint32_t offset, uint32_t value)
{
	struct nvme_vfio_ctrlr *vctrlr = nvme_vfio_ctrlr(ctrlr);

	assert(offset <= sizeof(struct spdk_nvme_registers) - 4);
	SPDK_DEBUGLOG(nvme_vfio, "ctrlr %s: offset 0x%x, value 0x%x\n", ctrlr->trid.traddr, offset, value);

	return spdk_vfio_user_pci_bar_access(vctrlr->dev, VFIO_PCI_BAR0_REGION_INDEX,
					     offset, 4, &value, true);
}

static int
nvme_vfio_ctrlr_set_reg_8(struct spdk_nvme_ctrlr *ctrlr, uint32_t offset, uint64_t value)
{
	struct nvme_vfio_ctrlr *vctrlr = nvme_vfio_ctrlr(ctrlr);

	assert(offset <= sizeof(struct spdk_nvme_registers) - 8);
	SPDK_DEBUGLOG(nvme_vfio, "ctrlr %s: offset 0x%x, value 0x%"PRIx64"\n", ctrlr->trid.traddr, offset,
		      value);

	return spdk_vfio_user_pci_bar_access(vctrlr->dev, VFIO_PCI_BAR0_REGION_INDEX,
					     offset, 8, &value, true);
}

static int
nvme_vfio_ctrlr_get_reg_4(struct spdk_nvme_ctrlr *ctrlr, uint32_t offset, uint32_t *value)
{
	struct nvme_vfio_ctrlr *vctrlr = nvme_vfio_ctrlr(ctrlr);
	int ret;

	assert(offset <= sizeof(struct spdk_nvme_registers) - 4);

	ret = spdk_vfio_user_pci_bar_access(vctrlr->dev, VFIO_PCI_BAR0_REGION_INDEX,
					    offset, 4, value, false);
	if (ret != 0) {
		SPDK_ERRLOG("ctrlr %p, offset %x\n", ctrlr, offset);
		return ret;
	}

	SPDK_DEBUGLOG(nvme_vfio, "ctrlr %s: offset 0x%x, value 0x%x\n", ctrlr->trid.traddr, offset, *value);

	return 0;
}

static int
nvme_vfio_ctrlr_get_reg_8(struct spdk_nvme_ctrlr *ctrlr, uint32_t offset, uint64_t *value)
{
	struct nvme_vfio_ctrlr *vctrlr = nvme_vfio_ctrlr(ctrlr);
	int ret;

	assert(offset <= sizeof(struct spdk_nvme_registers) - 8);

	ret = spdk_vfio_user_pci_bar_access(vctrlr->dev, VFIO_PCI_BAR0_REGION_INDEX,
					    offset, 8, value, false);
	if (ret != 0) {
		SPDK_ERRLOG("ctrlr %p, offset %x\n", ctrlr, offset);
		return ret;
	}

	SPDK_DEBUGLOG(nvme_vfio, "ctrlr %s: offset 0x%x, value 0x%"PRIx64"\n", ctrlr->trid.traddr, offset,
		      *value);

	return 0;
}

static int
nvme_vfio_ctrlr_set_asq(struct spdk_nvme_ctrlr *ctrlr, uint64_t value)
{
	return nvme_vfio_ctrlr_set_reg_8(ctrlr, offsetof(struct spdk_nvme_registers, asq),
					 value);
}

static int
nvme_vfio_ctrlr_set_acq(struct spdk_nvme_ctrlr *ctrlr, uint64_t value)
{
	return nvme_vfio_ctrlr_set_reg_8(ctrlr, offsetof(struct spdk_nvme_registers, acq),
					 value);
}

static int
nvme_vfio_ctrlr_set_aqa(struct spdk_nvme_ctrlr *ctrlr, const union spdk_nvme_aqa_register *aqa)
{
	return nvme_vfio_ctrlr_set_reg_4(ctrlr, offsetof(struct spdk_nvme_registers, aqa.raw),
					 aqa->raw);
}

/* Instead of using path as the bar0 file descriptor, we can also use
 * SPARSE MMAP to get the doorbell mmaped address.
 */
static int
nvme_vfio_setup_bar0(struct nvme_vfio_ctrlr *vctrlr, const char *path)
{
	volatile uint32_t *doorbell;
	int fd;

	fd = open(path, O_RDWR);
	if (fd < 0) {
		SPDK_ERRLOG("Failed to open file %s\n", path);
		return fd;
	}

	doorbell = mmap(NULL, 0x1000, PROT_READ | PROT_WRITE, MAP_SHARED, fd, 0x1000);
	if (doorbell == MAP_FAILED) {
		SPDK_ERRLOG("Failed to mmap file %s\n", path);
		close(fd);
		return -EFAULT;
	}

	vctrlr->bar0_fd = fd;
	vctrlr->doorbell_base = doorbell;

	return 0;
}

static void
nvme_vfio_bar0_destruct(struct nvme_vfio_ctrlr *vctrlr)
{
	if (vctrlr->doorbell_base) {
		munmap((void *)vctrlr->doorbell_base, 0x1000);
	}

	close(vctrlr->bar0_fd);
}

static struct spdk_nvme_ctrlr *
	nvme_vfio_ctrlr_construct(const struct spdk_nvme_transport_id *trid,
			  const struct spdk_nvme_ctrlr_opts *opts,
			  void *devhandle)
{
	struct nvme_vfio_ctrlr *vctrlr;
	struct nvme_pcie_ctrlr *pctrlr;
	uint16_t cmd_reg;
	union spdk_nvme_cap_register cap;
	int ret;
	char ctrlr_path[PATH_MAX];
	char ctrlr_bar0[PATH_MAX];

	snprintf(ctrlr_path, sizeof(ctrlr_path), "%s/cntrl", trid->traddr);
	snprintf(ctrlr_bar0, sizeof(ctrlr_bar0), "%s/bar0", trid->traddr);

	ret = access(ctrlr_path, F_OK);
	if (ret != 0) {
		SPDK_ERRLOG("Access path %s failed\n", ctrlr_path);
		return NULL;
	}

	ret = access(ctrlr_bar0, F_OK);
	if (ret != 0) {
		SPDK_ERRLOG("Access path %s failed\n", ctrlr_bar0);
		return NULL;
	}

	vctrlr = calloc(1, sizeof(*vctrlr));
	if (!vctrlr) {
		return NULL;
	}

	ret = nvme_vfio_setup_bar0(vctrlr, ctrlr_bar0);
	if (ret != 0) {
		free(vctrlr);
		return NULL;
	}

	vctrlr->dev = spdk_vfio_user_setup(ctrlr_path);
	if (!vctrlr->dev) {
		SPDK_ERRLOG("Error to setup vfio device\n");
		nvme_vfio_bar0_destruct(vctrlr);
		free(vctrlr);
		return NULL;
	}

	pctrlr = &vctrlr->pctrlr;
	pctrlr->doorbell_base = vctrlr->doorbell_base;
	pctrlr->ctrlr.is_removed = false;
	pctrlr->ctrlr.opts = *opts;
	pctrlr->ctrlr.trid = *trid;
	pctrlr->ctrlr.opts.use_cmb_sqs = false;

	ret = nvme_ctrlr_construct(&pctrlr->ctrlr);
	if (ret != 0) {
		goto exit;
	}

	/* Enable PCI busmaster and disable INTx */
	ret = spdk_vfio_user_pci_bar_access(vctrlr->dev, VFIO_PCI_CONFIG_REGION_INDEX, 4, 2,
					    &cmd_reg, false);
	if (ret != 0) {
		SPDK_ERRLOG("Read PCI CMD REG failed\n");
		goto exit;
	}
	cmd_reg |= 0x404;
	ret = spdk_vfio_user_pci_bar_access(vctrlr->dev, VFIO_PCI_CONFIG_REGION_INDEX, 4, 2,
					    &cmd_reg, true);
	if (ret != 0) {
		SPDK_ERRLOG("Write PCI CMD REG failed\n");
		goto exit;
	}

	if (nvme_ctrlr_get_cap(&pctrlr->ctrlr, &cap)) {
		SPDK_ERRLOG("get_cap() failed\n");
		goto exit;
	}

	/* Doorbell stride is 2 ^ (dstrd + 2),
	 * but we want multiples of 4, so drop the + 2 */
	pctrlr->doorbell_stride_u32 = 1 << cap.bits.dstrd;

	ret = nvme_pcie_ctrlr_construct_admin_qpair(&pctrlr->ctrlr, pctrlr->ctrlr.opts.admin_queue_size);
	if (ret != 0) {
		nvme_ctrlr_destruct(&pctrlr->ctrlr);
		goto exit;
	}

	/* Construct the primary process properties */
	ret = nvme_ctrlr_add_process(&pctrlr->ctrlr, 0);
	if (ret != 0) {
		nvme_ctrlr_destruct(&pctrlr->ctrlr);
		goto exit;
	}

	return &pctrlr->ctrlr;

exit:
	nvme_vfio_bar0_destruct(vctrlr);
	spdk_vfio_user_release(vctrlr->dev);
	free(vctrlr);
	return NULL;
}

static int
nvme_vfio_ctrlr_scan(struct spdk_nvme_probe_ctx *probe_ctx,
		     bool direct_connect)
{
	int ret;

	if (probe_ctx->trid.trtype != SPDK_NVME_TRANSPORT_VFIOUSER) {
		SPDK_ERRLOG("Can only use SPDK_NVME_TRANSPORT_VFIOUSER");
		return -EINVAL;
	}

	ret = access(probe_ctx->trid.traddr, F_OK);
	if (ret != 0) {
		SPDK_ERRLOG("Error to access file %s\n", probe_ctx->trid.traddr);
		return ret;
	}
	SPDK_DEBUGLOG(nvme_vfio, "Scan controller : %s\n", probe_ctx->trid.traddr);

	return nvme_ctrlr_probe(&probe_ctx->trid, probe_ctx, NULL);
}

static int
nvme_vfio_ctrlr_enable(struct spdk_nvme_ctrlr *ctrlr)
{
	struct nvme_pcie_qpair *vadminq = nvme_pcie_qpair(ctrlr->adminq);
	union spdk_nvme_aqa_register aqa;

	if (nvme_vfio_ctrlr_set_asq(ctrlr, vadminq->cmd_bus_addr)) {
		SPDK_ERRLOG("set_asq() failed\n");
		return -EIO;
	}

	if (nvme_vfio_ctrlr_set_acq(ctrlr, vadminq->cpl_bus_addr)) {
		SPDK_ERRLOG("set_acq() failed\n");
		return -EIO;
	}

	aqa.raw = 0;
	/* acqs and asqs are 0-based. */
	aqa.bits.acqs = nvme_pcie_qpair(ctrlr->adminq)->num_entries - 1;
	aqa.bits.asqs = nvme_pcie_qpair(ctrlr->adminq)->num_entries - 1;

	if (nvme_vfio_ctrlr_set_aqa(ctrlr, &aqa)) {
		SPDK_ERRLOG("set_aqa() failed\n");
		return -EIO;
	}

	return 0;
}

static int
nvme_vfio_ctrlr_destruct(struct spdk_nvme_ctrlr *ctrlr)
{
	struct nvme_vfio_ctrlr *vctrlr = nvme_vfio_ctrlr(ctrlr);

	if (ctrlr->adminq) {
		nvme_pcie_qpair_destroy(ctrlr->adminq);
	}

	nvme_ctrlr_destruct_finish(ctrlr);

	nvme_ctrlr_free_processes(ctrlr);

	nvme_vfio_bar0_destruct(vctrlr);
	spdk_vfio_user_release(vctrlr->dev);
	free(vctrlr);

	return 0;
}

static  uint32_t
nvme_vfio_ctrlr_get_max_xfer_size(struct spdk_nvme_ctrlr *ctrlr)
{
	return NVME_MAX_XFER_SIZE;
}

static uint16_t
nvme_vfio_ctrlr_get_max_sges(struct spdk_nvme_ctrlr *ctrlr)
{
	return NVME_MAX_SGES;
}

const struct spdk_nvme_transport_ops vfio_ops = {
	.name = "VFIOUSER",
	.type = SPDK_NVME_TRANSPORT_VFIOUSER,
	.ctrlr_construct = nvme_vfio_ctrlr_construct,
	.ctrlr_scan = nvme_vfio_ctrlr_scan,
	.ctrlr_destruct = nvme_vfio_ctrlr_destruct,
	.ctrlr_enable = nvme_vfio_ctrlr_enable,

	.ctrlr_set_reg_4 = nvme_vfio_ctrlr_set_reg_4,
	.ctrlr_set_reg_8 = nvme_vfio_ctrlr_set_reg_8,
	.ctrlr_get_reg_4 = nvme_vfio_ctrlr_get_reg_4,
	.ctrlr_get_reg_8 = nvme_vfio_ctrlr_get_reg_8,

	.ctrlr_get_max_xfer_size = nvme_vfio_ctrlr_get_max_xfer_size,
	.ctrlr_get_max_sges = nvme_vfio_ctrlr_get_max_sges,

	.ctrlr_create_io_qpair = nvme_pcie_ctrlr_create_io_qpair,
	.ctrlr_delete_io_qpair = nvme_pcie_ctrlr_delete_io_qpair,
	.ctrlr_connect_qpair = nvme_pcie_ctrlr_connect_qpair,
	.ctrlr_disconnect_qpair = nvme_pcie_ctrlr_disconnect_qpair,
	.admin_qpair_abort_aers = nvme_pcie_admin_qpair_abort_aers,

	.qpair_reset = nvme_pcie_qpair_reset,
	.qpair_abort_reqs = nvme_pcie_qpair_abort_reqs,
	.qpair_submit_request = nvme_pcie_qpair_submit_request,
	.qpair_process_completions = nvme_pcie_qpair_process_completions,

	.poll_group_create = nvme_pcie_poll_group_create,
	.poll_group_connect_qpair = nvme_pcie_poll_group_connect_qpair,
	.poll_group_disconnect_qpair = nvme_pcie_poll_group_disconnect_qpair,
	.poll_group_add = nvme_pcie_poll_group_add,
	.poll_group_remove = nvme_pcie_poll_group_remove,
	.poll_group_process_completions = nvme_pcie_poll_group_process_completions,
	.poll_group_destroy = nvme_pcie_poll_group_destroy,
};

SPDK_NVME_TRANSPORT_REGISTER(vfio, &vfio_ops);

SPDK_LOG_REGISTER_COMPONENT(nvme_vfio)