vnic_rq.c

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/*
 * Copyright 2008-2010 Cisco Systems, Inc.  All rights reserved.
 * Copyright 2007 Nuova Systems, Inc.  All rights reserved.
 *
 * This program is free software; you may redistribute it and/or modify
 * it under the terms of the GNU General Public License as published by
 * the Free Software Foundation; version 2 of the License.
 *
 * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND,
 * EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF
 * MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND
 * NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS
 * BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN
 * ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN
 * CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
 * SOFTWARE.
 *
 */

#include <linux/kernel.h>
#include <linux/errno.h>
#include <linux/types.h>
#include <linux/pci.h>
#include <linux/delay.h>
#include <linux/slab.h>

#include "vnic_dev.h"
#include "vnic_rq.h"

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

    vdev = rq->vdev;

    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;
}

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;

    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);

    err = vnic_dev_alloc_desc_ring(vdev, &rq->ring, desc_count, desc_size);
    if (err)
        return err;

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

    return 0;
}

static 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;

    /* 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);
}

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);
}