Changes in uspace/lib/virtio/virtio.c [417aaafb:1e472ee] in mainline

File:

• uspace/lib/virtio/virtio.c (modified) (2 diffs)

uspace/lib/virtio/virtio.c

@@ -39 +39 @@
 #include <libarch/barrier.h>
 
+/** Allocate DMA buffers
+ *
+ * @param buffers[in]  Number of buffers to allocate.
+ * @param size[in]     Size of each buffer.
+ * @param write[in]    True if the buffers are writable by the driver, false
+ *                     otherwise.
+ * @param buf[out]     Output array holding virtual addresses of the allocated
+ *                     buffers.
+ * @param buf_p[out]   Output array holding physical addresses of the allocated
+ *                     buffers.
+ *
+ * The buffers can be deallocated by virtio_net_teardown_bufs().
+ *
+ * @return  EOK on success or error code.
+ */
+errno_t virtio_setup_dma_bufs(unsigned int buffers, size_t size,
+    bool write, void *buf[], uintptr_t buf_p[])
+{
+        /*
+         * Allocate all buffers at once in one large chunk.
+         */
+        void *virt = AS_AREA_ANY;
+        uintptr_t phys;
+        errno_t rc = dmamem_map_anonymous(buffers * size, 0,
+            write ? AS_AREA_WRITE : AS_AREA_READ, 0, &phys, &virt);
+        if (rc != EOK)
+                return rc;
+
+        ddf_msg(LVL_NOTE, "DMA buffers: %p-%p", virt, virt + buffers * size);
+
+        /*
+         * Calculate addresses of the individual buffers for easy access.
+         */
+        for (unsigned i = 0; i < buffers; i++) {
+                buf[i] = virt + i * size;
+                buf_p[i] = phys + i * size;
+        }
+
+        return EOK;
+}
+
+/** Deallocate DMA buffers
+ *
+ * @param buf[in]  Array holding the virtual addresses of the DMA buffers
+ *                 previously allocated by virtio_net_setup_bufs().
+ */
+extern void virtio_teardown_dma_bufs(void *buf[])
+{
+        if (buf[0]) {
+                dmamem_unmap_anonymous(buf[0]);
+                buf[0] = NULL;
+        }
+}
+
 void virtio_virtq_desc_set(virtio_dev_t *vdev, uint16_t num, uint16_t descno,
     uint64_t addr, uint32_t len, uint16_t flags, uint16_t next)
@@ -57 +111 @@
         return pio_read_le16(&d->next);
 }
+
+/** Create free descriptor list from the unused VIRTIO descriptors
+ *
+ * @param vdev[in]   VIRTIO device for which the free list will be created.
+ * @param num[in]    Index of the virtqueue for which the free list will be
+ *                   created.
+ * @param size[in]   Number of descriptors on the free list. The free list will
+ *                   contain descriptors starting from 0 to \a size - 1.
+ * @param head[out]  Variable that will hold the VIRTIO descriptor at the head
+ *                   of the free list.
+ */
+void virtio_create_desc_free_list(virtio_dev_t *vdev, uint16_t num,
+    uint16_t size, uint16_t *head)
+{
+        for (unsigned i = 0; i < size; i++) {
+                virtio_virtq_desc_set(vdev, num, i, 0, 0,
+                    VIRTQ_DESC_F_NEXT, (i + 1 == size) ? -1U : i + 1);
+        }
+        *head = 0;
+}
+
+/** Allocate a descriptor from the free list
+ *
+ * @param vdev[in]      VIRTIO device with the free list.
+ * @param num[in]       Index of the virtqueue with free list.
+ * @param head[in,out]  Head of the free list.
+ *
+ * @return  Allocated descriptor or 0xFFFF if the list is empty.
+ */
+uint16_t virtio_alloc_desc(virtio_dev_t *vdev, uint16_t num, uint16_t *head)
+{
+        virtq_t *q = &vdev->queues[num];
+        fibril_mutex_lock(&q->lock);
+        uint16_t descno = *head;
+        if (descno != (uint16_t) -1U)
+                *head = virtio_virtq_desc_get_next(vdev, num, descno);
+        fibril_mutex_unlock(&q->lock);
+        return descno;
+}
+
+/** Free a descriptor into the free list
+ *
+ * @param vdev[in]      VIRTIO device with the free list.
+ * @param num[in]       Index of the virtqueue with free list.
+ * @param head[in,out]  Head of the free list.
+ * @param descno[in]    The freed descriptor.
+ */
+void virtio_free_desc(virtio_dev_t *vdev, uint16_t num, uint16_t *head,
+    uint16_t descno)
+{
+        virtq_t *q = &vdev->queues[num];
+        fibril_mutex_lock(&q->lock);
+        virtio_virtq_desc_set(vdev, num, descno, 0, 0, VIRTQ_DESC_F_NEXT,
+            *head);
+        *head = descno;
+        fibril_mutex_unlock(&q->lock);
+}
+
 
 void virtio_virtq_produce_available(virtio_dev_t *vdev, uint16_t num,