drivers/net/ethernet/cisco/enic/vnic_rq.c

   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
  31 static 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_KERNEL);
  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
  66 void 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
  85 int 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
 114 static 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
 138 void 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         vnic_rq_init_start(rq, cq_index, 0, 0, error_interrupt_enable,
 143                            error_interrupt_offset);
 144 }
 145
 146 unsigned int vnic_rq_error_status(struct vnic_rq *rq)
 147 {
 148         return ioread32(&rq->ctrl->error_status);
 149 }
 150
 151 void vnic_rq_enable(struct vnic_rq *rq)
 152 {
 153         iowrite32(1, &rq->ctrl->enable);
 154 }
 155
 156 int vnic_rq_disable(struct vnic_rq *rq)
 157 {
 158         unsigned int wait;
 159         struct vnic_dev *vdev = rq->vdev;
 160         int i;
 161
 162         /* Due to a race condition with clearing RQ "mini-cache" in hw, we need
 163          * to disable the RQ twice to guarantee that stale descriptors are not
 164          * used when this RQ is re-enabled.
 165          */
 166         for (i = 0; i < 2; i++) {
 167                 iowrite32(0, &rq->ctrl->enable);
 168
 169                 /* Wait for HW to ACK disable request */
 170                 for (wait = 20000; wait > 0; wait--)
 171                         if (!ioread32(&rq->ctrl->running))
 172                                 break;
 173                 if (!wait) {
 174                         vdev_neterr(vdev, "Failed to disable RQ[%d]\n",
 175                                     rq->index);
 176
 177                         return -ETIMEDOUT;
 178                 }
 179         }
 180
 181         return 0;
 182 }
 183
 184 void vnic_rq_clean(struct vnic_rq *rq,
 185         void (*buf_clean)(struct vnic_rq *rq, struct vnic_rq_buf *buf))
 186 {
 187         struct vnic_rq_buf *buf;
 188         u32 fetch_index;
 189         unsigned int count = rq->ring.desc_count;
 190         int i;
 191
 192         buf = rq->to_clean;
 193
 194         for (i = 0; i < rq->ring.desc_count; i++) {
 195                 (*buf_clean)(rq, buf);
 196                 buf = buf->next;
 197         }
 198         rq->ring.desc_avail = rq->ring.desc_count - 1;
 199
 200         /* Use current fetch_index as the ring starting point */
 201         fetch_index = ioread32(&rq->ctrl->fetch_index);
 202
 203         if (fetch_index == 0xFFFFFFFF) { /* check for hardware gone  */
 204                 /* Hardware surprise removal: reset fetch_index */
 205                 fetch_index = 0;
 206         }
 207         rq->to_use = rq->to_clean =
 208                 &rq->bufs[fetch_index / VNIC_RQ_BUF_BLK_ENTRIES(count)]
 209                         [fetch_index % VNIC_RQ_BUF_BLK_ENTRIES(count)];
 210         iowrite32(fetch_index, &rq->ctrl->posted_index);
 211
 212         /* Anytime we write fetch_index, we need to re-write 0 to rq->enable
 213          * to re-sync internal VIC state.
 214          */
 215         iowrite32(0, &rq->ctrl->enable);
 216
 217         vnic_dev_clear_desc_ring(&rq->ring);
 218 }
 219