virtio_pci: split out legacy device support

Move everything dealing with legacy devices out to virtio_pci_legacy.c.
Expose common code APIs in virtio_pci.h

Signed-off-by: Michael S. Tsirkin <mst@redhat.com>

1 files changed, 323 insertions, 0 deletions

diff --git a/drivers/virtio/virtio_pci_legacy.c b/drivers/virtio/virtio_pci_legacy.c
new file mode 100644
index 000000000000..c3393d47097f
--- /dev/null
+++ b/drivers/virtio/virtio_pci_legacy.c
@@ -0,0 +1,323 @@
+/*
+ * Virtio PCI driver
+ *
+ * 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
+ *
+ * Authors:
+ *  Anthony Liguori  <aliguori@us.ibm.com>
+ *
+ * This work is licensed under the terms of the GNU GPL, version 2 or later.
+ * See the COPYING file in the top-level directory.
+ *
+ */
+
+#include "virtio_pci.h"
+
+/* Qumranet donated their vendor ID for devices 0x1000 thru 0x10FF. */
+static const struct pci_device_id virtio_pci_id_table[] = {
+        { PCI_DEVICE(0x1af4, PCI_ANY_ID) },
+        { 0 }
+};
+
+MODULE_DEVICE_TABLE(pci, virtio_pci_id_table);
+
+/* 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 ioread32(vp_dev->ioaddr + VIRTIO_PCI_HOST_FEATURES);
+}
+
+/* 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. */
+        iowrite32(vdev->features, vp_dev->ioaddr + VIRTIO_PCI_GUEST_FEATURES);
+
+        return 0;
+}
+
+/* virtio config->get() implementation */
+static void vp_get(struct virtio_device *vdev, unsigned offset,
+                   void *buf, unsigned len)
+{
+        struct virtio_pci_device *vp_dev = to_vp_device(vdev);
+        void __iomem *ioaddr = vp_dev->ioaddr +
+                                VIRTIO_PCI_CONFIG(vp_dev) + 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 offset,
+                   const void *buf, unsigned len)
+{
+        struct virtio_pci_device *vp_dev = to_vp_device(vdev);
+        void __iomem *ioaddr = vp_dev->ioaddr +
+                                VIRTIO_PCI_CONFIG(vp_dev) + 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 ioread8(vp_dev->ioaddr + VIRTIO_PCI_STATUS);
+}
+
+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);
+        iowrite8(status, vp_dev->ioaddr + VIRTIO_PCI_STATUS);
+}
+
+static void vp_reset(struct virtio_device *vdev)
+{
+        struct virtio_pci_device *vp_dev = to_vp_device(vdev);
+        /* 0 status means a reset. */
+        iowrite8(0, vp_dev->ioaddr + VIRTIO_PCI_STATUS);
+        /* Flush out the status write, and flush in device writes,
+         * including MSi-X interrupts, if any. */
+        ioread8(vp_dev->ioaddr + VIRTIO_PCI_STATUS);
+        /* Flush pending VQ/configuration callbacks. */
+        vp_synchronize_vectors(vdev);
+}
+
+static u16 vp_config_vector(struct virtio_pci_device *vp_dev, u16 vector)
+{
+        /* Setup the vector used for configuration events */
+        iowrite16(vector, vp_dev->ioaddr + VIRTIO_MSI_CONFIG_VECTOR);
+        /* Verify we had enough resources to assign the vector */
+        /* Will also flush the write out to device */
+        return ioread16(vp_dev->ioaddr + VIRTIO_MSI_CONFIG_VECTOR);
+}
+
+static struct virtqueue *setup_vq(struct virtio_pci_device *vp_dev,
+                                  struct virtio_pci_vq_info *info,
+                                  unsigned index,
+                                  void (*callback)(struct virtqueue *vq),
+                                  const char *name,
+                                  u16 msix_vec)
+{
+        struct virtqueue *vq;
+        unsigned long size;
+        u16 num;
+        int err;
+
+        /* Select the queue we're interested in */
+        iowrite16(index, vp_dev->ioaddr + VIRTIO_PCI_QUEUE_SEL);
+
+        /* Check if queue is either not available or already active. */
+        num = ioread16(vp_dev->ioaddr + VIRTIO_PCI_QUEUE_NUM);
+        if (!num || ioread32(vp_dev->ioaddr + VIRTIO_PCI_QUEUE_PFN))
+                return ERR_PTR(-ENOENT);
+
+        info->num = num;
+        info->msix_vector = msix_vec;
+
+        size = PAGE_ALIGN(vring_size(num, VIRTIO_PCI_VRING_ALIGN));
+        info->queue = alloc_pages_exact(size, GFP_KERNEL|__GFP_ZERO);
+        if (info->queue == NULL)
+                return ERR_PTR(-ENOMEM);
+
+        /* activate the queue */
+        iowrite32(virt_to_phys(info->queue) >> VIRTIO_PCI_QUEUE_ADDR_SHIFT,
+                  vp_dev->ioaddr + VIRTIO_PCI_QUEUE_PFN);
+
+        /* create the vring */
+        vq = vring_new_virtqueue(index, info->num,
+                                 VIRTIO_PCI_VRING_ALIGN, &vp_dev->vdev,
+                                 true, info->queue, vp_notify, callback, name);
+        if (!vq) {
+                err = -ENOMEM;
+                goto out_activate_queue;
+        }
+
+        vq->priv = (void __force *)vp_dev->ioaddr + VIRTIO_PCI_QUEUE_NOTIFY;
+
+        if (msix_vec != VIRTIO_MSI_NO_VECTOR) {
+                iowrite16(msix_vec, vp_dev->ioaddr + VIRTIO_MSI_QUEUE_VECTOR);
+                msix_vec = ioread16(vp_dev->ioaddr + VIRTIO_MSI_QUEUE_VECTOR);
+                if (msix_vec == VIRTIO_MSI_NO_VECTOR) {
+                        err = -EBUSY;
+                        goto out_assign;
+                }
+        }
+
+        return vq;
+
+out_assign:
+        vring_del_virtqueue(vq);
+out_activate_queue:
+        iowrite32(0, vp_dev->ioaddr + VIRTIO_PCI_QUEUE_PFN);
+        free_pages_exact(info->queue, size);
+        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);
+        unsigned long size;
+
+        iowrite16(vq->index, vp_dev->ioaddr + VIRTIO_PCI_QUEUE_SEL);
+
+        if (vp_dev->msix_enabled) {
+                iowrite16(VIRTIO_MSI_NO_VECTOR,
+                          vp_dev->ioaddr + VIRTIO_MSI_QUEUE_VECTOR);
+                /* Flush the write out to device */
+                ioread8(vp_dev->ioaddr + VIRTIO_PCI_ISR);
+        }
+
+        vring_del_virtqueue(vq);
+
+        /* Select and deactivate the queue */
+        iowrite32(0, vp_dev->ioaddr + VIRTIO_PCI_QUEUE_PFN);
+
+        size = PAGE_ALIGN(vring_size(info->num, VIRTIO_PCI_VRING_ALIGN));
+        free_pages_exact(info->queue, size);
+}
+
+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,
+        .get_features   = vp_get_features,
+        .finalize_features = vp_finalize_features,
+        .bus_name       = vp_bus_name,
+        .set_vq_affinity = vp_set_vq_affinity,
+};
+
+/* the PCI probing function */
+static int virtio_pci_probe(struct pci_dev *pci_dev,
+                            const struct pci_device_id *id)
+{
+        struct virtio_pci_device *vp_dev;
+        int err;
+
+        /* We only own devices >= 0x1000 and <= 0x103f: leave the rest. */
+        if (pci_dev->device < 0x1000 || pci_dev->device > 0x103f)
+                return -ENODEV;
+
+        if (pci_dev->revision != VIRTIO_PCI_ABI_VERSION) {
+                printk(KERN_ERR "virtio_pci: expected ABI version %d, got %d\n",
+                       VIRTIO_PCI_ABI_VERSION, pci_dev->revision);
+                return -ENODEV;
+        }
+
+        /* allocate our structure and fill it out */
+        vp_dev = kzalloc(sizeof(struct virtio_pci_device), GFP_KERNEL);
+        if (vp_dev == NULL)
+                return -ENOMEM;
+
+        vp_dev->vdev.dev.parent = &pci_dev->dev;
+        vp_dev->vdev.dev.release = virtio_pci_release_dev;
+        vp_dev->vdev.config = &virtio_pci_config_ops;
+        vp_dev->pci_dev = pci_dev;
+        INIT_LIST_HEAD(&vp_dev->virtqueues);
+        spin_lock_init(&vp_dev->lock);
+
+        /* Disable MSI/MSIX to bring device to a known good state. */
+        pci_msi_off(pci_dev);
+
+        /* enable the device */
+        err = pci_enable_device(pci_dev);
+        if (err)
+                goto out;
+
+        err = pci_request_regions(pci_dev, "virtio-pci");
+        if (err)
+                goto out_enable_device;
+
+        vp_dev->ioaddr = pci_iomap(pci_dev, 0, 0);
+        if (vp_dev->ioaddr == NULL) {
+                err = -ENOMEM;
+                goto out_req_regions;
+        }
+
+        vp_dev->isr = vp_dev->ioaddr + VIRTIO_PCI_ISR;
+
+        pci_set_drvdata(pci_dev, vp_dev);
+        pci_set_master(pci_dev);
+
+        /* we use the subsystem vendor/device id as the virtio vendor/device
+         * id.  this allows us to use the same PCI vendor/device id for all
+         * virtio devices and to identify the particular virtio driver by
+         * the subsystem ids */
+        vp_dev->vdev.id.vendor = pci_dev->subsystem_vendor;
+        vp_dev->vdev.id.device = pci_dev->subsystem_device;
+
+        vp_dev->config_vector = vp_config_vector;
+        vp_dev->setup_vq = setup_vq;
+        vp_dev->del_vq = del_vq;
+
+        /* finally register the virtio device */
+        err = register_virtio_device(&vp_dev->vdev);
+        if (err)
+                goto out_set_drvdata;
+
+        return 0;
+
+out_set_drvdata:
+        pci_iounmap(pci_dev, vp_dev->ioaddr);
+out_req_regions:
+        pci_release_regions(pci_dev);
+out_enable_device:
+        pci_disable_device(pci_dev);
+out:
+        kfree(vp_dev);
+        return err;
+}
+
+static void virtio_pci_remove(struct pci_dev *pci_dev)
+{
+        struct virtio_pci_device *vp_dev = pci_get_drvdata(pci_dev);
+
+        unregister_virtio_device(&vp_dev->vdev);
+
+        vp_del_vqs(&vp_dev->vdev);
+        pci_iounmap(pci_dev, vp_dev->ioaddr);
+        pci_release_regions(pci_dev);
+        pci_disable_device(pci_dev);
+        kfree(vp_dev);
+}
+
+static struct pci_driver virtio_pci_driver = {
+        .name           = "virtio-pci",
+        .id_table       = virtio_pci_id_table,
+        .probe          = virtio_pci_probe,
+        .remove         = virtio_pci_remove,
+#ifdef CONFIG_PM_SLEEP
+        .driver.pm      = &virtio_pci_pm_ops,
+#endif
+};
+
+module_pci_driver(virtio_pci_driver);