/* SPDX-License-Identifier: BSD-3-Clause
 * Copyright(c) 2021 Intel Corporation
 */

#include <bus_pci_driver.h>
#include <rte_devargs.h>
#include <rte_dmadev_pmd.h>
#include <rte_malloc.h>
#include <rte_atomic.h>

#include "idxd_internal.h"

#define IDXD_VENDOR_ID		0x8086
#define IDXD_DEVICE_ID_SPR	0x0B25

#define IDXD_PMD_DMADEV_NAME_PCI dmadev_idxd_pci

const struct rte_pci_id pci_id_idxd_map[] = {
	{ RTE_PCI_DEVICE(IDXD_VENDOR_ID, IDXD_DEVICE_ID_SPR) },
	{ .vendor_id = 0, /* sentinel */ },
};

static inline int
idxd_pci_dev_command(struct idxd_dmadev *idxd, enum rte_idxd_cmds command)
{
	uint32_t err_code;
	uint16_t qid = idxd->qid;
	int i = 0;

	if (command >= idxd_disable_wq && command <= idxd_reset_wq)
		qid = (1 << qid);
	rte_spinlock_lock(&idxd->u.pci->lk);
	idxd->u.pci->regs->cmd = (command << IDXD_CMD_SHIFT) | qid;

	do {
		rte_pause();
		err_code = idxd->u.pci->regs->cmdstatus;
		if (++i >= 1000) {
			IDXD_PMD_ERR("Timeout waiting for command response from HW");
			rte_spinlock_unlock(&idxd->u.pci->lk);
			err_code &= CMDSTATUS_ERR_MASK;
			return err_code;
		}
	} while (err_code & CMDSTATUS_ACTIVE_MASK);
	rte_spinlock_unlock(&idxd->u.pci->lk);

	err_code &= CMDSTATUS_ERR_MASK;
	return err_code;
}

static uint32_t *
idxd_get_wq_cfg(struct idxd_pci_common *pci, uint8_t wq_idx)
{
	return RTE_PTR_ADD(pci->wq_regs_base,
			(uintptr_t)wq_idx << (5 + pci->wq_cfg_sz));
}

static int
idxd_is_wq_enabled(struct idxd_dmadev *idxd)
{
	uint32_t state = idxd_get_wq_cfg(idxd->u.pci, idxd->qid)[wq_state_idx];
	return ((state >> WQ_STATE_SHIFT) & WQ_STATE_MASK) == 0x1;
}

static int
idxd_pci_dev_stop(struct rte_dma_dev *dev)
{
	struct idxd_dmadev *idxd = dev->fp_obj->dev_private;
	uint8_t err_code;

	if (!idxd_is_wq_enabled(idxd)) {
		IDXD_PMD_ERR("Work queue %d already disabled", idxd->qid);
		return 0;
	}

	err_code = idxd_pci_dev_command(idxd, idxd_disable_wq);
	if (err_code || idxd_is_wq_enabled(idxd)) {
		IDXD_PMD_ERR("Failed disabling work queue %d, error code: %#x",
				idxd->qid, err_code);
		return err_code == 0 ? -1 : -err_code;
	}
	IDXD_PMD_DEBUG("Work queue %d disabled OK", idxd->qid);

	return 0;
}

static int
idxd_pci_dev_start(struct rte_dma_dev *dev)
{
	struct idxd_dmadev *idxd = dev->fp_obj->dev_private;
	uint8_t err_code;

	if (idxd_is_wq_enabled(idxd)) {
		IDXD_PMD_WARN("WQ %d already enabled", idxd->qid);
		return 0;
	}

	if (idxd->desc_ring == NULL) {
		IDXD_PMD_ERR("WQ %d has not been fully configured", idxd->qid);
		return -EINVAL;
	}

	err_code = idxd_pci_dev_command(idxd, idxd_enable_wq);
	if (err_code || !idxd_is_wq_enabled(idxd)) {
		IDXD_PMD_ERR("Failed enabling work queue %d, error code: %#x",
				idxd->qid, err_code);
		return err_code == 0 ? -1 : -err_code;
	}
	IDXD_PMD_DEBUG("Work queue %d enabled OK", idxd->qid);

	return 0;
}

static int
idxd_pci_dev_close(struct rte_dma_dev *dev)
{
	struct idxd_dmadev *idxd = dev->fp_obj->dev_private;
	uint8_t err_code;
	int is_last_wq;

	if (idxd_is_wq_enabled(idxd)) {
		/* disable the wq */
		err_code = idxd_pci_dev_command(idxd, idxd_disable_wq);
		if (err_code) {
			IDXD_PMD_ERR("Error disabling wq: code %#x", err_code);
			return err_code;
		}
		IDXD_PMD_DEBUG("IDXD WQ disabled OK");
	}

	/* free device memory */
	IDXD_PMD_DEBUG("Freeing device driver memory");
	rte_free(idxd->batch_comp_ring);
	rte_free(idxd->desc_ring);

	/* if this is the last WQ on the device, disable the device and free
	 * the PCI struct
	 */
	is_last_wq = rte_atomic16_dec_and_test(&idxd->u.pci->ref_count);
	if (is_last_wq) {
		/* disable the device */
		err_code = idxd_pci_dev_command(idxd, idxd_disable_dev);
		if (err_code) {
			IDXD_PMD_ERR("Error disabling device: code %#x", err_code);
			return err_code;
		}
		IDXD_PMD_DEBUG("IDXD device disabled OK");
		rte_free(idxd->u.pci);
	}

	return 0;
}

static const struct rte_dma_dev_ops idxd_pci_ops = {
	.dev_close = idxd_pci_dev_close,
	.dev_dump = idxd_dump,
	.dev_configure = idxd_configure,
	.vchan_setup = idxd_vchan_setup,
	.dev_info_get = idxd_info_get,
	.stats_get = idxd_stats_get,
	.stats_reset = idxd_stats_reset,
	.dev_start = idxd_pci_dev_start,
	.dev_stop = idxd_pci_dev_stop,
	.vchan_status = idxd_vchan_status,
};

/* each portal uses 4 x 4k pages */
#define IDXD_PORTAL_SIZE (4096 * 4)

static int
init_pci_device(struct rte_pci_device *dev, struct idxd_dmadev *idxd,
		unsigned int max_queues)
{
	struct idxd_pci_common *pci;
	uint8_t nb_groups, nb_engines, nb_wqs;
	uint16_t grp_offset, wq_offset; /* how far into bar0 the regs are */
	uint16_t wq_size, total_wq_size;
	uint8_t lg2_max_batch, lg2_max_copy_size;
	unsigned int i, err_code;

	pci = rte_malloc(NULL, sizeof(*pci), 0);
	if (pci == NULL) {
		IDXD_PMD_ERR("%s: Can't allocate memory", __func__);
		err_code = -1;
		goto err;
	}
	memset(pci, 0, sizeof(*pci));
	rte_spinlock_init(&pci->lk);

	/* assign the bar registers, and then configure device */
	pci->regs = dev->mem_resource[0].addr;
	grp_offset = (uint16_t)pci->regs->offsets[0];
	pci->grp_regs = RTE_PTR_ADD(pci->regs, grp_offset * 0x100);
	wq_offset = (uint16_t)(pci->regs->offsets[0] >> 16);
	pci->wq_regs_base = RTE_PTR_ADD(pci->regs, wq_offset * 0x100);
	pci->portals = dev->mem_resource[2].addr;
	pci->wq_cfg_sz = (pci->regs->wqcap >> 24) & 0x0F;

	/* sanity check device status */
	if (pci->regs->gensts & GENSTS_DEV_STATE_MASK) {
		/* need function-level-reset (FLR) or is enabled */
		IDXD_PMD_ERR("Device status is not disabled, cannot init");
		err_code = -1;
		goto err;
	}
	if (pci->regs->cmdstatus & CMDSTATUS_ACTIVE_MASK) {
		/* command in progress */
		IDXD_PMD_ERR("Device has a command in progress, cannot init");
		err_code = -1;
		goto err;
	}

	/* read basic info about the hardware for use when configuring */
	nb_groups = (uint8_t)pci->regs->grpcap;
	nb_engines = (uint8_t)pci->regs->engcap;
	nb_wqs = (uint8_t)(pci->regs->wqcap >> 16);
	total_wq_size = (uint16_t)pci->regs->wqcap;
	lg2_max_copy_size = (uint8_t)(pci->regs->gencap >> 16) & 0x1F;
	lg2_max_batch = (uint8_t)(pci->regs->gencap >> 21) & 0x0F;

	IDXD_PMD_DEBUG("nb_groups = %u, nb_engines = %u, nb_wqs = %u",
			nb_groups, nb_engines, nb_wqs);

	/* zero out any old config */
	for (i = 0; i < nb_groups; i++) {
		pci->grp_regs[i].grpengcfg = 0;
		pci->grp_regs[i].grpwqcfg[0] = 0;
	}
	for (i = 0; i < nb_wqs; i++)
		idxd_get_wq_cfg(pci, i)[0] = 0;

	/* limit queues if necessary */
	if (max_queues != 0 && nb_wqs > max_queues) {
		nb_wqs = max_queues;
		if (nb_engines > max_queues)
			nb_engines = max_queues;
		if (nb_groups > max_queues)
			nb_engines = max_queues;
		IDXD_PMD_DEBUG("Limiting queues to %u", nb_wqs);
	}

	/* put each engine into a separate group to avoid reordering */
	if (nb_groups > nb_engines)
		nb_groups = nb_engines;
	if (nb_groups < nb_engines)
		nb_engines = nb_groups;

	/* assign engines to groups, round-robin style */
	for (i = 0; i < nb_engines; i++) {
		IDXD_PMD_DEBUG("Assigning engine %u to group %u",
				i, i % nb_groups);
		pci->grp_regs[i % nb_groups].grpengcfg |= (1ULL << i);
	}

	/* now do the same for queues and give work slots to each queue */
	wq_size = total_wq_size / nb_wqs;
	IDXD_PMD_DEBUG("Work queue size = %u, max batch = 2^%u, max copy = 2^%u",
			wq_size, lg2_max_batch, lg2_max_copy_size);
	for (i = 0; i < nb_wqs; i++) {
		/* add engine "i" to a group */
		IDXD_PMD_DEBUG("Assigning work queue %u to group %u",
				i, i % nb_groups);
		pci->grp_regs[i % nb_groups].grpwqcfg[0] |= (1ULL << i);
		/* now configure it, in terms of size, max batch, mode */
		idxd_get_wq_cfg(pci, i)[wq_size_idx] = wq_size;
		idxd_get_wq_cfg(pci, i)[wq_mode_idx] = (1 << WQ_PRIORITY_SHIFT) |
				WQ_MODE_DEDICATED;
		idxd_get_wq_cfg(pci, i)[wq_sizes_idx] = lg2_max_copy_size |
				(lg2_max_batch << WQ_BATCH_SZ_SHIFT);
	}

	/* dump the group configuration to output */
	for (i = 0; i < nb_groups; i++) {
		IDXD_PMD_DEBUG("## Group %d", i);
		IDXD_PMD_DEBUG("    GRPWQCFG: %"PRIx64, pci->grp_regs[i].grpwqcfg[0]);
		IDXD_PMD_DEBUG("    GRPENGCFG: %"PRIx64, pci->grp_regs[i].grpengcfg);
		IDXD_PMD_DEBUG("    GRPFLAGS: %"PRIx32, pci->grp_regs[i].grpflags);
	}

	idxd->u.pci = pci;
	idxd->max_batches = wq_size;
	idxd->max_batch_size = 1 << lg2_max_batch;

	/* enable the device itself */
	err_code = idxd_pci_dev_command(idxd, idxd_enable_dev);
	if (err_code) {
		IDXD_PMD_ERR("Error enabling device: code %#x", err_code);
		goto err;
	}
	IDXD_PMD_DEBUG("IDXD Device enabled OK");

	return nb_wqs;

err:
	free(pci);
	return err_code;
}

static int
idxd_dmadev_probe_pci(struct rte_pci_driver *drv, struct rte_pci_device *dev)
{
	struct idxd_dmadev idxd = {0};
	uint8_t nb_wqs;
	int qid, ret = 0;
	char name[PCI_PRI_STR_SIZE];
	unsigned int max_queues = 0;

	rte_pci_device_name(&dev->addr, name, sizeof(name));
	IDXD_PMD_INFO("Init %s on NUMA node %d", name, dev->device.numa_node);
	dev->device.driver = &drv->driver;

	if (dev->device.devargs && dev->device.devargs->args[0] != '\0') {
		/* if the number of devargs grows beyond just 1, use rte_kvargs */
		if (sscanf(dev->device.devargs->args,
				"max_queues=%u", &max_queues) != 1) {
			IDXD_PMD_ERR("Invalid device parameter: '%s'",
					dev->device.devargs->args);
			return -1;
		}
	}

	ret = init_pci_device(dev, &idxd, max_queues);
	if (ret < 0) {
		IDXD_PMD_ERR("Error initializing PCI hardware");
		return ret;
	}
	if (idxd.u.pci->portals == NULL) {
		IDXD_PMD_ERR("Error, invalid portal assigned during initialization\n");
		free(idxd.u.pci);
		return -EINVAL;
	}
	nb_wqs = (uint8_t)ret;

	/* set up one device for each queue */
	for (qid = 0; qid < nb_wqs; qid++) {
		char qname[32];

		/* add the queue number to each device name */
		snprintf(qname, sizeof(qname), "%s-q%d", name, qid);
		idxd.qid = qid;
		idxd.portal = RTE_PTR_ADD(idxd.u.pci->portals,
				qid * IDXD_PORTAL_SIZE);
		if (idxd_is_wq_enabled(&idxd))
			IDXD_PMD_ERR("Error, WQ %u seems enabled", qid);
		ret = idxd_dmadev_create(qname, &dev->device,
				&idxd, &idxd_pci_ops);
		if (ret != 0) {
			IDXD_PMD_ERR("Failed to create dmadev %s", name);
			if (qid == 0) /* if no devices using this, free pci */
				free(idxd.u.pci);
			return ret;
		}
		rte_atomic16_inc(&idxd.u.pci->ref_count);
	}

	return 0;
}

static int
idxd_dmadev_destroy(const char *name)
{
	int ret = 0;

	/* rte_dma_close is called by pmd_release */
	ret = rte_dma_pmd_release(name);
	if (ret)
		IDXD_PMD_DEBUG("Device cleanup failed");

	return ret;
}

static int
idxd_dmadev_remove_pci(struct rte_pci_device *dev)
{
	int i = 0;
	char name[PCI_PRI_STR_SIZE];

	rte_pci_device_name(&dev->addr, name, sizeof(name));

	IDXD_PMD_INFO("Closing %s on NUMA node %d", name, dev->device.numa_node);

	RTE_DMA_FOREACH_DEV(i) {
		struct rte_dma_info info;
		rte_dma_info_get(i, &info);
		if (strncmp(name, info.dev_name, strlen(name)) == 0)
			idxd_dmadev_destroy(info.dev_name);
	}

	return 0;
}

struct rte_pci_driver idxd_pmd_drv_pci = {
	.id_table = pci_id_idxd_map,
	.drv_flags = RTE_PCI_DRV_NEED_MAPPING,
	.probe = idxd_dmadev_probe_pci,
	.remove = idxd_dmadev_remove_pci,
};

RTE_PMD_REGISTER_PCI(IDXD_PMD_DMADEV_NAME_PCI, idxd_pmd_drv_pci);
RTE_PMD_REGISTER_PCI_TABLE(IDXD_PMD_DMADEV_NAME_PCI, pci_id_idxd_map);
RTE_PMD_REGISTER_KMOD_DEP(IDXD_PMD_DMADEV_NAME_PCI, "vfio-pci");
RTE_PMD_REGISTER_PARAM_STRING(dmadev_idxd_pci, "max_queues=0");
