From 57f0f512b273f60d52568b8c6b77e17f5636edc0 Mon Sep 17 00:00:00 2001 From: André Fabian Silva Delgado Date: Wed, 5 Aug 2015 17:04:01 -0300 Subject: Initial import --- drivers/virtio/virtio_pci_legacy.c | 256 +++++++++++++++++++++++++++++++++++++ 1 file changed, 256 insertions(+) create mode 100644 drivers/virtio/virtio_pci_legacy.c (limited to 'drivers/virtio/virtio_pci_legacy.c') diff --git a/drivers/virtio/virtio_pci_legacy.c b/drivers/virtio/virtio_pci_legacy.c new file mode 100644 index 000000000..256a5278a --- /dev/null +++ b/drivers/virtio/virtio_pci_legacy.c @@ -0,0 +1,256 @@ +/* + * 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 + * Rusty Russell + * Michael S. Tsirkin + * + * 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_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 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 */ +int virtio_pci_legacy_probe(struct virtio_pci_device *vp_dev) +{ + struct pci_dev *pci_dev = vp_dev->pci_dev; + + /* 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; + } + + vp_dev->ioaddr = pci_iomap(pci_dev, 0, 0); + if (!vp_dev->ioaddr) + return -ENOMEM; + + vp_dev->isr = vp_dev->ioaddr + VIRTIO_PCI_ISR; + + /* 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->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 pci_dev *pci_dev = vp_dev->pci_dev; + + pci_iounmap(pci_dev, vp_dev->ioaddr); +} -- cgit v1.2.3-54-g00ecf