summaryrefslogtreecommitdiffstats
path: root/drivers/virtio/virtio_pci_legacy.c
diff options
context:
space:
mode:
Diffstat (limited to 'drivers/virtio/virtio_pci_legacy.c')
-rw-r--r--drivers/virtio/virtio_pci_legacy.c235
1 files changed, 235 insertions, 0 deletions
diff --git a/drivers/virtio/virtio_pci_legacy.c b/drivers/virtio/virtio_pci_legacy.c
new file mode 100644
index 000000000..2257f1b3d
--- /dev/null
+++ b/drivers/virtio/virtio_pci_legacy.c
@@ -0,0 +1,235 @@
+// SPDX-License-Identifier: GPL-2.0-or-later
+/*
+ * Virtio PCI driver - legacy device support
+ *
+ * This module allows virtio devices to be used over a virtual PCI device.
+ * This can be used with QEMU based VMMs like KVM or Xen.
+ *
+ * Copyright IBM Corp. 2007
+ * Copyright Red Hat, Inc. 2014
+ *
+ * Authors:
+ * Anthony Liguori <aliguori@us.ibm.com>
+ * Rusty Russell <rusty@rustcorp.com.au>
+ * Michael S. Tsirkin <mst@redhat.com>
+ */
+
+#include "linux/virtio_pci_legacy.h"
+#include "virtio_pci_common.h"
+
+/* virtio config->get_features() implementation */
+static u64 vp_get_features(struct virtio_device *vdev)
+{
+ struct virtio_pci_device *vp_dev = to_vp_device(vdev);
+
+ /* When someone needs more than 32 feature bits, we'll need to
+ * steal a bit to indicate that the rest are somewhere else. */
+ return vp_legacy_get_features(&vp_dev->ldev);
+}
+
+/* virtio config->finalize_features() implementation */
+static int vp_finalize_features(struct virtio_device *vdev)
+{
+ struct virtio_pci_device *vp_dev = to_vp_device(vdev);
+
+ /* Give virtio_ring a chance to accept features. */
+ vring_transport_features(vdev);
+
+ /* Make sure we don't have any features > 32 bits! */
+ BUG_ON((u32)vdev->features != vdev->features);
+
+ /* We only support 32 feature bits. */
+ vp_legacy_set_features(&vp_dev->ldev, vdev->features);
+
+ return 0;
+}
+
+/* virtio config->get() implementation */
+static void vp_get(struct virtio_device *vdev, unsigned int offset,
+ void *buf, unsigned int len)
+{
+ struct virtio_pci_device *vp_dev = to_vp_device(vdev);
+ void __iomem *ioaddr = vp_dev->ldev.ioaddr +
+ VIRTIO_PCI_CONFIG_OFF(vp_dev->msix_enabled) +
+ offset;
+ u8 *ptr = buf;
+ int i;
+
+ for (i = 0; i < len; i++)
+ ptr[i] = ioread8(ioaddr + i);
+}
+
+/* the config->set() implementation. it's symmetric to the config->get()
+ * implementation */
+static void vp_set(struct virtio_device *vdev, unsigned int offset,
+ const void *buf, unsigned int len)
+{
+ struct virtio_pci_device *vp_dev = to_vp_device(vdev);
+ void __iomem *ioaddr = vp_dev->ldev.ioaddr +
+ VIRTIO_PCI_CONFIG_OFF(vp_dev->msix_enabled) +
+ offset;
+ const u8 *ptr = buf;
+ int i;
+
+ for (i = 0; i < len; i++)
+ iowrite8(ptr[i], ioaddr + i);
+}
+
+/* config->{get,set}_status() implementations */
+static u8 vp_get_status(struct virtio_device *vdev)
+{
+ struct virtio_pci_device *vp_dev = to_vp_device(vdev);
+ return vp_legacy_get_status(&vp_dev->ldev);
+}
+
+static void vp_set_status(struct virtio_device *vdev, u8 status)
+{
+ struct virtio_pci_device *vp_dev = to_vp_device(vdev);
+ /* We should never be setting status to 0. */
+ BUG_ON(status == 0);
+ vp_legacy_set_status(&vp_dev->ldev, status);
+}
+
+static void vp_reset(struct virtio_device *vdev)
+{
+ struct virtio_pci_device *vp_dev = to_vp_device(vdev);
+ /* 0 status means a reset. */
+ vp_legacy_set_status(&vp_dev->ldev, 0);
+ /* Flush out the status write, and flush in device writes,
+ * including MSi-X interrupts, if any. */
+ vp_legacy_get_status(&vp_dev->ldev);
+ /* Flush pending VQ/configuration callbacks. */
+ vp_synchronize_vectors(vdev);
+}
+
+static u16 vp_config_vector(struct virtio_pci_device *vp_dev, u16 vector)
+{
+ return vp_legacy_config_vector(&vp_dev->ldev, vector);
+}
+
+static struct virtqueue *setup_vq(struct virtio_pci_device *vp_dev,
+ struct virtio_pci_vq_info *info,
+ unsigned int index,
+ void (*callback)(struct virtqueue *vq),
+ const char *name,
+ bool ctx,
+ u16 msix_vec)
+{
+ struct virtqueue *vq;
+ u16 num;
+ int err;
+ u64 q_pfn;
+
+ /* Check if queue is either not available or already active. */
+ num = vp_legacy_get_queue_size(&vp_dev->ldev, index);
+ if (!num || vp_legacy_get_queue_enable(&vp_dev->ldev, index))
+ return ERR_PTR(-ENOENT);
+
+ info->msix_vector = msix_vec;
+
+ /* create the vring */
+ vq = vring_create_virtqueue(index, num,
+ VIRTIO_PCI_VRING_ALIGN, &vp_dev->vdev,
+ true, false, ctx,
+ vp_notify, callback, name);
+ if (!vq)
+ return ERR_PTR(-ENOMEM);
+
+ vq->num_max = num;
+
+ q_pfn = virtqueue_get_desc_addr(vq) >> VIRTIO_PCI_QUEUE_ADDR_SHIFT;
+ if (q_pfn >> 32) {
+ dev_err(&vp_dev->pci_dev->dev,
+ "platform bug: legacy virtio-pci must not be used with RAM above 0x%llxGB\n",
+ 0x1ULL << (32 + PAGE_SHIFT - 30));
+ err = -E2BIG;
+ goto out_del_vq;
+ }
+
+ /* activate the queue */
+ vp_legacy_set_queue_address(&vp_dev->ldev, index, q_pfn);
+
+ vq->priv = (void __force *)vp_dev->ldev.ioaddr + VIRTIO_PCI_QUEUE_NOTIFY;
+
+ if (msix_vec != VIRTIO_MSI_NO_VECTOR) {
+ msix_vec = vp_legacy_queue_vector(&vp_dev->ldev, index, msix_vec);
+ if (msix_vec == VIRTIO_MSI_NO_VECTOR) {
+ err = -EBUSY;
+ goto out_deactivate;
+ }
+ }
+
+ return vq;
+
+out_deactivate:
+ vp_legacy_set_queue_address(&vp_dev->ldev, index, 0);
+out_del_vq:
+ vring_del_virtqueue(vq);
+ return ERR_PTR(err);
+}
+
+static void del_vq(struct virtio_pci_vq_info *info)
+{
+ struct virtqueue *vq = info->vq;
+ struct virtio_pci_device *vp_dev = to_vp_device(vq->vdev);
+
+ if (vp_dev->msix_enabled) {
+ vp_legacy_queue_vector(&vp_dev->ldev, vq->index,
+ VIRTIO_MSI_NO_VECTOR);
+ /* Flush the write out to device */
+ ioread8(vp_dev->ldev.ioaddr + VIRTIO_PCI_ISR);
+ }
+
+ /* Select and deactivate the queue */
+ vp_legacy_set_queue_address(&vp_dev->ldev, vq->index, 0);
+
+ vring_del_virtqueue(vq);
+}
+
+static const struct virtio_config_ops virtio_pci_config_ops = {
+ .get = vp_get,
+ .set = vp_set,
+ .get_status = vp_get_status,
+ .set_status = vp_set_status,
+ .reset = vp_reset,
+ .find_vqs = vp_find_vqs,
+ .del_vqs = vp_del_vqs,
+ .synchronize_cbs = vp_synchronize_vectors,
+ .get_features = vp_get_features,
+ .finalize_features = vp_finalize_features,
+ .bus_name = vp_bus_name,
+ .set_vq_affinity = vp_set_vq_affinity,
+ .get_vq_affinity = vp_get_vq_affinity,
+};
+
+/* the PCI probing function */
+int virtio_pci_legacy_probe(struct virtio_pci_device *vp_dev)
+{
+ struct virtio_pci_legacy_device *ldev = &vp_dev->ldev;
+ struct pci_dev *pci_dev = vp_dev->pci_dev;
+ int rc;
+
+ ldev->pci_dev = pci_dev;
+
+ rc = vp_legacy_probe(ldev);
+ if (rc)
+ return rc;
+
+ vp_dev->isr = ldev->isr;
+ vp_dev->vdev.id = ldev->id;
+
+ vp_dev->vdev.config = &virtio_pci_config_ops;
+
+ vp_dev->config_vector = vp_config_vector;
+ vp_dev->setup_vq = setup_vq;
+ vp_dev->del_vq = del_vq;
+
+ return 0;
+}
+
+void virtio_pci_legacy_remove(struct virtio_pci_device *vp_dev)
+{
+ struct virtio_pci_legacy_device *ldev = &vp_dev->ldev;
+
+ vp_legacy_remove(ldev);
+}
generated by cgit v1.2.3 (git 2.39.1) at 2024-11-04 04:42:37 +0000