uspace/lib/virtio/virtio.c

   1 /*
   2  * Copyright (c) 2018 Jakub Jermar
   3  * All rights reserved.
   4  *
   5  * Redistribution and use in source and binary forms, with or without
   6  * modification, are permitted provided that the following conditions
   7  * are met:
   8  *
   9  * - Redistributions of source code must retain the above copyright
  10  *   notice, this list of conditions and the following disclaimer.
  11  * - Redistributions in binary form must reproduce the above copyright
  12  *   notice, this list of conditions and the following disclaimer in the
  13  *   documentation and/or other materials provided with the distribution.
  14  * - The name of the author may not be used to endorse or promote products
  15  *   derived from this software without specific prior written permission.
  16  *
  17  * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR
  18  * IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
  19  * OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED.
  20  * IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT,
  21  * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT
  22  * NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
  23  * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
  24  * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
  25  * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF
  26  * THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
  27  */
  28
  29 /** @file VIRTIO support
  30  */
  31
  32 #include "virtio-pci.h"
  33
  34 #include <as.h>
  35 #include <align.h>
  36 #include <macros.h>
  37
  38 #include <ddf/log.h>
  39 #include <libarch/barrier.h>
  40
  41 void virtio_virtq_set_desc(virtio_dev_t *vdev, uint16_t num, uint16_t descno,
  42     uint64_t addr, uint32_t len, uint16_t flags, uint16_t next)
  43 {
  44         virtq_desc_t *d = &vdev->queues[num].desc[descno];
  45         pio_write_le64(&d->addr, addr);
  46         pio_write_le32(&d->len, len);
  47         pio_write_le16(&d->flags, flags);
  48         pio_write_le16(&d->next, next);
  49 }
  50
  51 void virtio_virtq_produce_available(virtio_dev_t *vdev, uint16_t num,
  52     uint16_t descno)
  53 {
  54         virtq_t *q = &vdev->queues[num];
  55
  56         uint16_t idx = pio_read_le16(&q->avail->idx);
  57         pio_write_le16(&q->avail->ring[idx], descno);
  58         write_barrier();
  59         pio_write_le16(&q->avail->idx, (idx + 1) % q->queue_size);
  60         write_barrier();
  61         pio_write_le16(q->notify, num);
  62 }
  63
  64 errno_t virtio_virtq_setup(virtio_dev_t *vdev, uint16_t num, uint16_t size)
  65 {
  66         virtq_t *q = &vdev->queues[num];
  67         virtio_pci_common_cfg_t *cfg = vdev->common_cfg;
  68
  69         /* Program the queue of our interest */
  70         pio_write_le16(&cfg->queue_select, num);
  71
  72         /* Trim the size of the queue as needed */
  73         if (size > pio_read_16(&cfg->queue_size)) {
  74                 ddf_msg(LVL_ERROR, "Virtq %u: not enough descriptors", num);
  75                 return ENOMEM;
  76         }
  77         pio_write_le16(&cfg->queue_size, size);
  78         ddf_msg(LVL_NOTE, "Virtq %u: %u descriptors", num, (unsigned) size);
  79
  80         size_t avail_offset = 0;
  81         size_t used_offset = 0;
  82
  83         /*
  84          * Compute the size of the needed DMA memory and also the offsets of
  85          * the individual components
  86          */
  87         size_t mem_size = sizeof(virtq_desc_t[size]);
  88         mem_size = ALIGN_UP(mem_size, _Alignof(virtq_avail_t));
  89         avail_offset = mem_size;
  90         mem_size += sizeof(virtq_avail_t) + sizeof(ioport16_t[size]) +
  91             sizeof(ioport16_t);
  92         mem_size = ALIGN_UP(mem_size, _Alignof(virtq_used_t));
  93         used_offset = mem_size;
  94         mem_size += sizeof(virtq_used_t) + sizeof(virtq_used_elem_t[size]) +
  95             sizeof(ioport16_t);
  96
  97         /*
  98          * Allocate DMA memory for the virtqueues
  99          */
 100         q->virt = AS_AREA_ANY;
 101         errno_t rc = dmamem_map_anonymous(mem_size, 0,
 102             AS_AREA_READ | AS_AREA_WRITE, 0, &q->phys, &q->virt);
 103         if (rc != EOK) {
 104                 q->virt = NULL;
 105                 return rc;
 106         }
 107
 108         q->size = mem_size;
 109         q->queue_size = size;
 110         q->desc = q->virt;
 111         q->avail = q->virt + avail_offset;
 112         q->used = q->virt + used_offset;
 113
 114         memset(q->virt, 0, q->size);
 115
 116         /*
 117          * Initialize the descriptor table
 118          */
 119         for (unsigned i = 0; i < size; i++) {
 120                 q->desc[i].addr = 0;
 121                 q->desc[i].len = 0;
 122                 q->desc[i].flags = 0;
 123         }
 124
 125         /*
 126          * Write the configured addresses to device's common config
 127          */
 128         pio_write_le64(&cfg->queue_desc, q->phys);
 129         pio_write_le64(&cfg->queue_avail, q->phys + avail_offset);
 130         pio_write_le64(&cfg->queue_used, q->phys + used_offset);
 131
 132         ddf_msg(LVL_NOTE, "DMA memory for virtq %d: virt=%p, phys=%p, size=%zu",
 133             num, q->virt, (void *) q->phys, q->size);
 134
 135         /* Determine virtq's notification address */
 136         q->notify = vdev->notify_base +
 137             pio_read_le16(&cfg->queue_notif_off) * vdev->notify_off_multiplier;
 138
 139         ddf_msg(LVL_NOTE, "notification register: %p", q->notify);
 140
 141         return rc;
 142 }
 143
 144 void virtio_virtq_teardown(virtio_dev_t *vdev, uint16_t num)
 145 {
 146         virtq_t *q = &vdev->queues[num];
 147         if (q->size)
 148                 dmamem_unmap_anonymous(q->virt);
 149 }
 150
 151 /**
 152  * Perform device initialization as described in section 3.1.1 of the
 153  * specification, steps 1 - 6.
 154  */
 155 errno_t virtio_device_setup_start(virtio_dev_t *vdev, uint32_t features)
 156 {
 157         virtio_pci_common_cfg_t *cfg = vdev->common_cfg;
 158
 159         /* 1. Reset the device */
 160         uint8_t status = VIRTIO_DEV_STATUS_RESET;
 161         pio_write_8(&cfg->device_status, status);
 162
 163         /* 2. Acknowledge we found the device */
 164         status |= VIRTIO_DEV_STATUS_ACKNOWLEDGE;
 165         pio_write_8(&cfg->device_status, status);
 166
 167         /* 3. We know how to drive the device */
 168         status |= VIRTIO_DEV_STATUS_DRIVER;
 169         pio_write_8(&cfg->device_status, status);
 170
 171         /* 4. Read the offered feature flags */
 172         pio_write_le32(&cfg->device_feature_select, VIRTIO_FEATURES_0_31);
 173         uint32_t device_features = pio_read_le32(&cfg->device_feature);
 174
 175         ddf_msg(LVL_NOTE, "offered features %x", device_features);
 176         features &= device_features;
 177
 178         if (!features)
 179                 return ENOTSUP;
 180
 181         /* 4. Write the accepted feature flags */
 182         pio_write_le32(&cfg->driver_feature_select, VIRTIO_FEATURES_0_31);
 183         pio_write_le32(&cfg->driver_feature, features);
 184
 185         ddf_msg(LVL_NOTE, "accepted features %x", features);
 186
 187         /* 5. Set FEATURES_OK */
 188         status |= VIRTIO_DEV_STATUS_FEATURES_OK;
 189         pio_write_8(&cfg->device_status, status);
 190
 191         /* 6. Test if the device supports our feature subset */
 192         status = pio_read_8(&cfg->device_status);
 193         if (!(status & VIRTIO_DEV_STATUS_FEATURES_OK))
 194                 return ENOTSUP;
 195
 196         return EOK;
 197 }
 198
 199 /**
 200  * Perform device initialization as described in section 3.1.1 of the
 201  * specification, step 8 (go live).
 202  */
 203 void virtio_device_setup_finalize(virtio_dev_t *vdev)
 204 {
 205         virtio_pci_common_cfg_t *cfg = vdev->common_cfg;
 206
 207         /* 8. Go live */
 208         uint8_t status = pio_read_8(&cfg->device_status);
 209         pio_write_8(&cfg->device_status, status | VIRTIO_DEV_STATUS_DRIVER_OK);
 210 }
 211
 212 void virtio_device_setup_fail(virtio_dev_t *vdev)
 213 {
 214         virtio_pci_common_cfg_t *cfg = vdev->common_cfg;
 215
 216         uint8_t status = pio_read_8(&cfg->device_status);
 217         pio_write_8(&cfg->device_status, status | VIRTIO_DEV_STATUS_FAILED);
 218 }
 219
 220 /** @}
 221  */