/*
 * Copyright 2008-2010 Cisco Systems, Inc.  All rights reserved.
 * Copyright 2007 Nuova Systems, Inc.  All rights reserved.
 *
 * Copyright (c) 2014, Cisco Systems, 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:
 *
 * 1. Redistributions of source code must retain the above copyright
 * notice, this list of conditions and the following disclaimer.
 *
 * 2. 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.
 *
 * 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 HOLDER 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 "vnic_dev.h"
#include "vnic_rq.h"

static int vnic_rq_alloc_bufs(struct vnic_rq *rq)
{
	struct vnic_rq_buf *buf;
	unsigned int i, j, count = rq->ring.desc_count;
	unsigned int blks = VNIC_RQ_BUF_BLKS_NEEDED(count);

	for (i = 0; i < blks; i++) {
		rq->bufs[i] = kzalloc(VNIC_RQ_BUF_BLK_SZ(count), GFP_ATOMIC);
		if (!rq->bufs[i])
			return -ENOMEM;
	}

	for (i = 0; i < blks; i++) {
		buf = rq->bufs[i];
		for (j = 0; j < VNIC_RQ_BUF_BLK_ENTRIES(count); j++) {
			buf->index = i * VNIC_RQ_BUF_BLK_ENTRIES(count) + j;
			buf->desc = (u8 *)rq->ring.descs +
				rq->ring.desc_size * buf->index;
			if (buf->index + 1 == count) {
				buf->next = rq->bufs[0];
				break;
			} else if (j + 1 == VNIC_RQ_BUF_BLK_ENTRIES(count)) {
				buf->next = rq->bufs[i + 1];
			} else {
				buf->next = buf + 1;
				buf++;
			}
		}
	}

	rq->to_use = rq->to_clean = rq->bufs[0];

	return 0;
}

int vnic_rq_mem_size(struct vnic_rq *rq, unsigned int desc_count,
	unsigned int desc_size)
{
	int mem_size = 0;

	mem_size += vnic_dev_desc_ring_size(&rq->ring, desc_count, desc_size);

	mem_size += VNIC_RQ_BUF_BLKS_NEEDED(rq->ring.desc_count) *
		VNIC_RQ_BUF_BLK_SZ(rq->ring.desc_count);

	return mem_size;
}

void vnic_rq_free(struct vnic_rq *rq)
{
	struct vnic_dev *vdev;
	unsigned int i;

	vdev = rq->vdev;

	vnic_dev_free_desc_ring(vdev, &rq->ring);

	for (i = 0; i < VNIC_RQ_BUF_BLKS_MAX; i++) {
		if (rq->bufs[i]) {
			kfree(rq->bufs[i]);
			rq->bufs[i] = NULL;
		}
	}

	rq->ctrl = NULL;
}

int vnic_rq_alloc(struct vnic_dev *vdev, struct vnic_rq *rq, unsigned int index,
	unsigned int desc_count, unsigned int desc_size)
{
	int err;
	char res_name[NAME_MAX];
	static int instance;

	rq->index = index;
	rq->vdev = vdev;

	rq->ctrl = vnic_dev_get_res(vdev, RES_TYPE_RQ, index);
	if (!rq->ctrl) {
		pr_err("Failed to hook RQ[%d] resource\n", index);
		return -EINVAL;
	}

	vnic_rq_disable(rq);

	snprintf(res_name, sizeof(res_name), "%d-rq-%d", instance++, index);
	err = vnic_dev_alloc_desc_ring(vdev, &rq->ring, desc_count, desc_size,
		rq->socket_id, res_name);
	if (err)
		return err;

	err = vnic_rq_alloc_bufs(rq);
	if (err) {
		vnic_rq_free(rq);
		return err;
	}

	return 0;
}

void vnic_rq_init_start(struct vnic_rq *rq, unsigned int cq_index,
	unsigned int fetch_index, unsigned int posted_index,
	unsigned int error_interrupt_enable,
	unsigned int error_interrupt_offset)
{
	u64 paddr;
	unsigned int count = rq->ring.desc_count;

	paddr = (u64)rq->ring.base_addr | VNIC_PADDR_TARGET;
	writeq(paddr, &rq->ctrl->ring_base);
	iowrite32(count, &rq->ctrl->ring_size);
	iowrite32(cq_index, &rq->ctrl->cq_index);
	iowrite32(error_interrupt_enable, &rq->ctrl->error_interrupt_enable);
	iowrite32(error_interrupt_offset, &rq->ctrl->error_interrupt_offset);
	iowrite32(0, &rq->ctrl->dropped_packet_count);
	iowrite32(0, &rq->ctrl->error_status);
	iowrite32(fetch_index, &rq->ctrl->fetch_index);
	iowrite32(posted_index, &rq->ctrl->posted_index);

	rq->to_use = rq->to_clean =
		&rq->bufs[fetch_index / VNIC_RQ_BUF_BLK_ENTRIES(count)]
			[fetch_index % VNIC_RQ_BUF_BLK_ENTRIES(count)];
}

void vnic_rq_init(struct vnic_rq *rq, unsigned int cq_index,
	unsigned int error_interrupt_enable,
	unsigned int error_interrupt_offset)
{
	u32 fetch_index = 0;
	/* Use current fetch_index as the ring starting point */
	fetch_index = ioread32(&rq->ctrl->fetch_index);

	if (fetch_index == 0xFFFFFFFF) { /* check for hardware gone  */
		/* Hardware surprise removal: reset fetch_index */
		fetch_index = 0;
	}

	vnic_rq_init_start(rq, cq_index,
		fetch_index, fetch_index,
		error_interrupt_enable,
		error_interrupt_offset);
}

void vnic_rq_error_out(struct vnic_rq *rq, unsigned int error)
{
	iowrite32(error, &rq->ctrl->error_status);
}

unsigned int vnic_rq_error_status(struct vnic_rq *rq)
{
	return ioread32(&rq->ctrl->error_status);
}

void vnic_rq_enable(struct vnic_rq *rq)
{
	iowrite32(1, &rq->ctrl->enable);
}

int vnic_rq_disable(struct vnic_rq *rq)
{
	unsigned int wait;

	iowrite32(0, &rq->ctrl->enable);

	/* Wait for HW to ACK disable request */
	for (wait = 0; wait < 1000; wait++) {
		if (!(ioread32(&rq->ctrl->running)))
			return 0;
		udelay(10);
	}

	pr_err("Failed to disable RQ[%d]\n", rq->index);

	return -ETIMEDOUT;
}

void vnic_rq_clean(struct vnic_rq *rq,
	void (*buf_clean)(struct vnic_rq *rq, struct vnic_rq_buf *buf))
{
	struct vnic_rq_buf *buf;
	u32 fetch_index;
	unsigned int count = rq->ring.desc_count;

	buf = rq->to_clean;

	while (vnic_rq_desc_used(rq) > 0) {

		(*buf_clean)(rq, buf);

		buf = rq->to_clean = buf->next;
		rq->ring.desc_avail++;
	}

	/* Use current fetch_index as the ring starting point */
	fetch_index = ioread32(&rq->ctrl->fetch_index);

	if (fetch_index == 0xFFFFFFFF) { /* check for hardware gone  */
		/* Hardware surprise removal: reset fetch_index */
		fetch_index = 0;
	}
	rq->to_use = rq->to_clean =
		&rq->bufs[fetch_index / VNIC_RQ_BUF_BLK_ENTRIES(count)]
			[fetch_index % VNIC_RQ_BUF_BLK_ENTRIES(count)];
	iowrite32(fetch_index, &rq->ctrl->posted_index);

	vnic_dev_clear_desc_ring(&rq->ring);
}
