Changeset 1e472ee in mainline for uspace/lib/virtio/virtio.c

Timestamp:

2018-06-28T19:23:42Z (7 years ago)

Author:

Jakub Jermar <jakub@…>

Branches:

lfn, master, serial, ticket/834-toolchain-update, topic/msim-upgrade, topic/simplify-dev-export

Children:

d3b2ffa

Parents:

331d024

Message:

Move DMA buffers allocation functions to libvirtio

File:

• uspace/lib/virtio/virtio.c (modified) (1 diff)

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)