linux/drivers/net/ethernet/cisco/enic/vnic_rq.c
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   1/*
   2 * Copyright 2008-2010 Cisco Systems, Inc.  All rights reserved.
   3 * Copyright 2007 Nuova Systems, Inc.  All rights reserved.
   4 *
   5 * This program is free software; you may redistribute it and/or modify
   6 * it under the terms of the GNU General Public License as published by
   7 * the Free Software Foundation; version 2 of the License.
   8 *
   9 * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND,
  10 * EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF
  11 * MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND
  12 * NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS
  13 * BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN
  14 * ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN
  15 * CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
  16 * SOFTWARE.
  17 *
  18 */
  19
  20#include <linux/kernel.h>
  21#include <linux/errno.h>
  22#include <linux/types.h>
  23#include <linux/pci.h>
  24#include <linux/delay.h>
  25#include <linux/slab.h>
  26
  27#include "vnic_dev.h"
  28#include "vnic_rq.h"
  29#include "enic.h"
  30
  31static int vnic_rq_alloc_bufs(struct vnic_rq *rq)
  32{
  33        struct vnic_rq_buf *buf;
  34        unsigned int i, j, count = rq->ring.desc_count;
  35        unsigned int blks = VNIC_RQ_BUF_BLKS_NEEDED(count);
  36
  37        for (i = 0; i < blks; i++) {
  38                rq->bufs[i] = kzalloc(VNIC_RQ_BUF_BLK_SZ(count), GFP_ATOMIC);
  39                if (!rq->bufs[i])
  40                        return -ENOMEM;
  41        }
  42
  43        for (i = 0; i < blks; i++) {
  44                buf = rq->bufs[i];
  45                for (j = 0; j < VNIC_RQ_BUF_BLK_ENTRIES(count); j++) {
  46                        buf->index = i * VNIC_RQ_BUF_BLK_ENTRIES(count) + j;
  47                        buf->desc = (u8 *)rq->ring.descs +
  48                                rq->ring.desc_size * buf->index;
  49                        if (buf->index + 1 == count) {
  50                                buf->next = rq->bufs[0];
  51                                break;
  52                        } else if (j + 1 == VNIC_RQ_BUF_BLK_ENTRIES(count)) {
  53                                buf->next = rq->bufs[i + 1];
  54                        } else {
  55                                buf->next = buf + 1;
  56                                buf++;
  57                        }
  58                }
  59        }
  60
  61        rq->to_use = rq->to_clean = rq->bufs[0];
  62
  63        return 0;
  64}
  65
  66void vnic_rq_free(struct vnic_rq *rq)
  67{
  68        struct vnic_dev *vdev;
  69        unsigned int i;
  70
  71        vdev = rq->vdev;
  72
  73        vnic_dev_free_desc_ring(vdev, &rq->ring);
  74
  75        for (i = 0; i < VNIC_RQ_BUF_BLKS_MAX; i++) {
  76                if (rq->bufs[i]) {
  77                        kfree(rq->bufs[i]);
  78                        rq->bufs[i] = NULL;
  79                }
  80        }
  81
  82        rq->ctrl = NULL;
  83}
  84
  85int vnic_rq_alloc(struct vnic_dev *vdev, struct vnic_rq *rq, unsigned int index,
  86        unsigned int desc_count, unsigned int desc_size)
  87{
  88        int err;
  89
  90        rq->index = index;
  91        rq->vdev = vdev;
  92
  93        rq->ctrl = vnic_dev_get_res(vdev, RES_TYPE_RQ, index);
  94        if (!rq->ctrl) {
  95                vdev_err(vdev, "Failed to hook RQ[%d] resource\n", index);
  96                return -EINVAL;
  97        }
  98
  99        vnic_rq_disable(rq);
 100
 101        err = vnic_dev_alloc_desc_ring(vdev, &rq->ring, desc_count, desc_size);
 102        if (err)
 103                return err;
 104
 105        err = vnic_rq_alloc_bufs(rq);
 106        if (err) {
 107                vnic_rq_free(rq);
 108                return err;
 109        }
 110
 111        return 0;
 112}
 113
 114static void vnic_rq_init_start(struct vnic_rq *rq, unsigned int cq_index,
 115        unsigned int fetch_index, unsigned int posted_index,
 116        unsigned int error_interrupt_enable,
 117        unsigned int error_interrupt_offset)
 118{
 119        u64 paddr;
 120        unsigned int count = rq->ring.desc_count;
 121
 122        paddr = (u64)rq->ring.base_addr | VNIC_PADDR_TARGET;
 123        writeq(paddr, &rq->ctrl->ring_base);
 124        iowrite32(count, &rq->ctrl->ring_size);
 125        iowrite32(cq_index, &rq->ctrl->cq_index);
 126        iowrite32(error_interrupt_enable, &rq->ctrl->error_interrupt_enable);
 127        iowrite32(error_interrupt_offset, &rq->ctrl->error_interrupt_offset);
 128        iowrite32(0, &rq->ctrl->dropped_packet_count);
 129        iowrite32(0, &rq->ctrl->error_status);
 130        iowrite32(fetch_index, &rq->ctrl->fetch_index);
 131        iowrite32(posted_index, &rq->ctrl->posted_index);
 132
 133        rq->to_use = rq->to_clean =
 134                &rq->bufs[fetch_index / VNIC_RQ_BUF_BLK_ENTRIES(count)]
 135                        [fetch_index % VNIC_RQ_BUF_BLK_ENTRIES(count)];
 136}
 137
 138void vnic_rq_init(struct vnic_rq *rq, unsigned int cq_index,
 139        unsigned int error_interrupt_enable,
 140        unsigned int error_interrupt_offset)
 141{
 142        u32 fetch_index = 0;
 143
 144        /* Use current fetch_index as the ring starting point */
 145        fetch_index = ioread32(&rq->ctrl->fetch_index);
 146
 147        if (fetch_index == 0xFFFFFFFF) { /* check for hardware gone  */
 148                /* Hardware surprise removal: reset fetch_index */
 149                fetch_index = 0;
 150        }
 151
 152        vnic_rq_init_start(rq, cq_index,
 153                fetch_index, fetch_index,
 154                error_interrupt_enable,
 155                error_interrupt_offset);
 156}
 157
 158unsigned int vnic_rq_error_status(struct vnic_rq *rq)
 159{
 160        return ioread32(&rq->ctrl->error_status);
 161}
 162
 163void vnic_rq_enable(struct vnic_rq *rq)
 164{
 165        iowrite32(1, &rq->ctrl->enable);
 166}
 167
 168int vnic_rq_disable(struct vnic_rq *rq)
 169{
 170        unsigned int wait;
 171        struct vnic_dev *vdev = rq->vdev;
 172        int i;
 173
 174        /* Due to a race condition with clearing RQ "mini-cache" in hw, we need
 175         * to disable the RQ twice to guarantee that stale descriptors are not
 176         * used when this RQ is re-enabled.
 177         */
 178        for (i = 0; i < 2; i++) {
 179                iowrite32(0, &rq->ctrl->enable);
 180
 181                /* Wait for HW to ACK disable request */
 182                for (wait = 20000; wait > 0; wait--)
 183                        if (!ioread32(&rq->ctrl->running))
 184                                break;
 185                if (!wait) {
 186                        vdev_neterr(vdev, "Failed to disable RQ[%d]\n",
 187                                    rq->index);
 188
 189                        return -ETIMEDOUT;
 190                }
 191        }
 192
 193        return 0;
 194}
 195
 196void vnic_rq_clean(struct vnic_rq *rq,
 197        void (*buf_clean)(struct vnic_rq *rq, struct vnic_rq_buf *buf))
 198{
 199        struct vnic_rq_buf *buf;
 200        u32 fetch_index;
 201        unsigned int count = rq->ring.desc_count;
 202        int i;
 203
 204        buf = rq->to_clean;
 205
 206        for (i = 0; i < rq->ring.desc_count; i++) {
 207                (*buf_clean)(rq, buf);
 208                buf = buf->next;
 209        }
 210        rq->ring.desc_avail = rq->ring.desc_count - 1;
 211
 212        /* Use current fetch_index as the ring starting point */
 213        fetch_index = ioread32(&rq->ctrl->fetch_index);
 214
 215        if (fetch_index == 0xFFFFFFFF) { /* check for hardware gone  */
 216                /* Hardware surprise removal: reset fetch_index */
 217                fetch_index = 0;
 218        }
 219        rq->to_use = rq->to_clean =
 220                &rq->bufs[fetch_index / VNIC_RQ_BUF_BLK_ENTRIES(count)]
 221                        [fetch_index % VNIC_RQ_BUF_BLK_ENTRIES(count)];
 222        iowrite32(fetch_index, &rq->ctrl->posted_index);
 223
 224        /* Anytime we write fetch_index, we need to re-write 0 to rq->enable
 225         * to re-sync internal VIC state.
 226         */
 227        iowrite32(0, &rq->ctrl->enable);
 228
 229        vnic_dev_clear_desc_ring(&rq->ring);
 230}
 231
 232