Differences:
1) Uses 4 pci capabilities to demark common, irq, notify and dev-specific areas.
2) Guest sets queue size, using host-provided maximum.
3) Guest sets queue alignment, rather than ABI-defined 4096.
4) More than 32 feature bits (a lot more!).
---
drivers/virtio/Makefile | 1
drivers/virtio/virtio_pci.c | 868 ++++++++++++++++++++++++++++++++++++++++++++
2 files changed, 869 insertions(+)
diff --git a/drivers/virtio/Makefile b/drivers/virtio/Makefile
--- a/drivers/virtio/Makefile
+++ b/drivers/virtio/Makefile
@@ -1,5 +1,6 @@
obj-$(CONFIG_VIRTIO) += virtio.o
obj-$(CONFIG_VIRTIO_RING) += virtio_ring.o
obj-$(CONFIG_VIRTIO_MMIO) += virtio_mmio.o
+obj-$(CONFIG_VIRTIO_PCI) += virtio_pci.o
obj-$(CONFIG_VIRTIO_PCI_LEGACY) += virtio_pci_legacy.o
obj-$(CONFIG_VIRTIO_BALLOON) += virtio_balloon.o
diff --git a/drivers/virtio/virtio_pci.c b/drivers/virtio/virtio_pci.c
new file mode 100644
--- /dev/null
+++ b/drivers/virtio/virtio_pci.c
@@ -0,0 +1,869 @@
+/*
+ * Virtio PCI driver
+ *
+ * This module allows virtio devices to be used over a virtual PCI
+ * device. Copyright 2011, Rusty Russell IBM Corporation, but based
+ * on the older virtio_pci_legacy.c, which was Copyright IBM
+ * Corp. 2007.
+ *
+ * This work is licensed under the terms of the GNU GPL, version 2 or later.
+ * See the COPYING file in the top-level directory.
+ *
+ */
+#define VIRTIO_PCI_NO_LEGACY
+#include <linux/module.h>
+#include <linux/list.h>
+#include <linux/pci.h>
+#include <linux/slab.h>
+#include <linux/interrupt.h>
+#include <linux/virtio.h>
+#include <linux/virtio_config.h>
+#include <linux/virtio_ring.h>
+#include <linux/virtio_pci.h>
+#include <linux/highmem.h>
+#include <linux/spinlock.h>
+
+MODULE_AUTHOR("Rusty Russell <[email protected]>");
+MODULE_DESCRIPTION("virtio-pci");
+MODULE_LICENSE("GPL");
+MODULE_VERSION("2");
+
+/* Use cacheline size as a good guess at a nice alignment. */
+#define VIRTIO_PCI_ALIGN SMP_CACHE_BYTES
+
+/* Our device structure */
+struct virtio_pci_device
+{
+ struct virtio_device vdev;
+ struct pci_dev *pci_dev;
+
+ /* The IO mapping for the PCI config space */
+ struct virtio_pci_common_cfg __iomem *common;
+ /* Where to read and clear interrupt */
+ u8 __iomem *isr;
+ /* Write the virtqueue index here to notify device of activity. */
+ __le16 __iomem *notify;
+ /* Device-specific data. */
+ void __iomem *device;
+
+ /* a list of queues so we can dispatch IRQs */
+ spinlock_t lock;
+ struct list_head virtqueues;
+
+ /* MSI-X support */
+ int msix_enabled;
+ int intx_enabled;
+ struct msix_entry *msix_entries;
+ /* Name strings for interrupts. This size should be enough,
+ * and I'm too lazy to allocate each name separately. */
+ char (*msix_names)[256];
+ /* Number of available vectors */
+ unsigned msix_vectors;
+ /* Vectors allocated, excluding per-vq vectors if any */
+ unsigned msix_used_vectors;
+ /* Whether we have vector per vq */
+ bool per_vq_vectors;
+};
+
+/* Constants for MSI-X */
+/* Use first vector for configuration changes, second and the rest for
+ * virtqueues Thus, we need at least 2 vectors for MSI. */
+enum {
+ VP_MSIX_CONFIG_VECTOR = 0,
+ VP_MSIX_VQ_VECTOR = 1,
+};
+
+struct virtio_pci_vq_info
+{
+ /* the actual virtqueue */
+ struct virtqueue *vq;
+
+ /* the number of entries in the queue */
+ int num;
+
+ /* the index of the queue */
+ int queue_index;
+
+ /* the virtual address of the ring queue */
+ void *queue;
+
+ /* the list node for the virtqueues list */
+ struct list_head node;
+
+ /* MSI-X vector (or none) */
+ unsigned msix_vector;
+};
+
+/* Qumranet donated their vendor ID for devices 0x1000 thru 0x10FF. */
+static struct pci_device_id virtio_pci_id_table[] = {
+ { 0x1af4, PCI_ANY_ID, PCI_ANY_ID, PCI_ANY_ID, 0, 0, 0 },
+ { 0 },
+};
+
+MODULE_DEVICE_TABLE(pci, virtio_pci_id_table);
+
+/* Convert a generic virtio device to our structure */
+static struct virtio_pci_device *to_vp_device(struct virtio_device *vdev)
+{
+ return container_of(vdev, struct virtio_pci_device, vdev);
+}
+
+/* There is no iowrite64. We use two 32-bit ops. */
+static void iowrite64(u64 val, const __le64 *addr)
+{
+ iowrite32((u32)val, (__le32 *)addr);
+ iowrite32(val >> 32, (__le32 *)addr + 1);
+}
+
+/* There is no ioread64. We use two 32-bit ops. */
+static u64 ioread64(__le64 *addr)
+{
+ return ioread32(addr) | ((u64)ioread32((__le32 *)addr + 1) << 32);
+}
+
+static u64 vp_get_features(struct virtio_device *vdev)
+{
+ struct virtio_pci_device *vp_dev = to_vp_device(vdev);
+ u64 features;
+
+ iowrite32(0, &vp_dev->common->device_feature_select);
+ features = ioread32(&vp_dev->common->device_feature);
+ iowrite32(1, &vp_dev->common->device_feature_select);
+ features |= ((u64)ioread32(&vp_dev->common->device_feature) << 32);
+ return features;
+}
+
+static void 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);
+
+ iowrite32(0, &vp_dev->common->guest_feature_select);
+ iowrite32((u32)vdev->features, &vp_dev->common->guest_feature);
+ iowrite32(1, &vp_dev->common->guest_feature_select);
+ iowrite32(vdev->features >> 32, &vp_dev->common->guest_feature);
+}
+
+/* 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->device + 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->device + 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->common->device_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->common->device_status);
+}
+
+/* wait for pending irq handlers */
+static void vp_synchronize_vectors(struct virtio_device *vdev)
+{
+ struct virtio_pci_device *vp_dev = to_vp_device(vdev);
+ int i;
+
+ if (vp_dev->intx_enabled)
+ synchronize_irq(vp_dev->pci_dev->irq);
+
+ for (i = 0; i < vp_dev->msix_vectors; ++i)
+ synchronize_irq(vp_dev->msix_entries[i].vector);
+}
+
+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->common->device_status);
+ /* Flush out the status write, and flush in device writes,
+ * including MSi-X interrupts, if any. */
+ ioread8(&vp_dev->common->device_status);
+ /* Flush pending VQ/configuration callbacks. */
+ vp_synchronize_vectors(vdev);
+}
+
+/* the notify function used when creating a virt queue */
+static void vp_notify(struct virtqueue *vq)
+{
+ struct virtio_pci_device *vp_dev = to_vp_device(vq->vdev);
+ struct virtio_pci_vq_info *info = vq->priv;
+
+ /* we write the queue's selector into the notification register to
+ * signal the other end */
+ iowrite16(info->queue_index, vp_dev->notify);
+}
+
+/* Handle a configuration change: Tell driver if it wants to know. */
+static irqreturn_t vp_config_changed(int irq, void *opaque)
+{
+ struct virtio_pci_device *vp_dev = opaque;
+ struct virtio_driver *drv;
+ drv = container_of(vp_dev->vdev.dev.driver,
+ struct virtio_driver, driver);
+
+ if (drv->config_changed)
+ drv->config_changed(&vp_dev->vdev);
+ return IRQ_HANDLED;
+}
+
+/* Notify all virtqueues on an interrupt. */
+static irqreturn_t vp_vring_interrupt(int irq, void *opaque)
+{
+ struct virtio_pci_device *vp_dev = opaque;
+ struct virtio_pci_vq_info *info;
+ irqreturn_t ret = IRQ_NONE;
+ unsigned long flags;
+
+ spin_lock_irqsave(&vp_dev->lock, flags);
+ list_for_each_entry(info, &vp_dev->virtqueues, node) {
+ if (vring_interrupt(irq, info->vq) == IRQ_HANDLED)
+ ret = IRQ_HANDLED;
+ }
+ spin_unlock_irqrestore(&vp_dev->lock, flags);
+
+ return ret;
+}
+
+/* A small wrapper to also acknowledge the interrupt when it's handled.
+ * I really need an EIO hook for the vring so I can ack the interrupt once we
+ * know that we'll be handling the IRQ but before we invoke the callback since
+ * the callback may notify the host which results in the host attempting to
+ * raise an interrupt that we would then mask once we acknowledged the
+ * interrupt. */
+static irqreturn_t vp_interrupt(int irq, void *opaque)
+{
+ struct virtio_pci_device *vp_dev = opaque;
+ u8 isr;
+
+ /* reading the ISR has the effect of also clearing it so it's very
+ * important to save off the value. */
+ isr = ioread8(vp_dev->isr);
+
+ /* It's definitely not us if the ISR was not high */
+ if (!isr)
+ return IRQ_NONE;
+
+ /* Configuration change? Tell driver if it wants to know. */
+ if (isr & VIRTIO_PCI_ISR_CONFIG)
+ vp_config_changed(irq, opaque);
+
+ return vp_vring_interrupt(irq, opaque);
+}
+
+static void vp_free_vectors(struct virtio_device *vdev)
+{
+ struct virtio_pci_device *vp_dev = to_vp_device(vdev);
+ int i;
+
+ if (vp_dev->intx_enabled) {
+ free_irq(vp_dev->pci_dev->irq, vp_dev);
+ vp_dev->intx_enabled = 0;
+ }
+
+ for (i = 0; i < vp_dev->msix_used_vectors; ++i)
+ free_irq(vp_dev->msix_entries[i].vector, vp_dev);
+
+ if (vp_dev->msix_enabled) {
+ /* Disable the vector used for configuration */
+ iowrite16(VIRTIO_MSI_NO_VECTOR, &vp_dev->common->msix_config);
+ /* Flush the write out to device */
+ ioread16(&vp_dev->common->msix_config);
+
+ pci_disable_msix(vp_dev->pci_dev);
+ vp_dev->msix_enabled = 0;
+ vp_dev->msix_vectors = 0;
+ }
+
+ vp_dev->msix_used_vectors = 0;
+ kfree(vp_dev->msix_names);
+ vp_dev->msix_names = NULL;
+ kfree(vp_dev->msix_entries);
+ vp_dev->msix_entries = NULL;
+}
+
+static int vp_request_msix_vectors(struct virtio_device *vdev, int nvectors,
+ bool per_vq_vectors)
+{
+ struct virtio_pci_device *vp_dev = to_vp_device(vdev);
+ const char *name = dev_name(&vp_dev->vdev.dev);
+ unsigned i, v;
+ int err = -ENOMEM;
+
+ vp_dev->msix_entries = kmalloc(nvectors * sizeof *vp_dev->msix_entries,
+ GFP_KERNEL);
+ if (!vp_dev->msix_entries)
+ goto error;
+ vp_dev->msix_names = kmalloc(nvectors * sizeof *vp_dev->msix_names,
+ GFP_KERNEL);
+ if (!vp_dev->msix_names)
+ goto error;
+
+ for (i = 0; i < nvectors; ++i)
+ vp_dev->msix_entries[i].entry = i;
+
+ /* pci_enable_msix returns positive if we can't get this many. */
+ err = pci_enable_msix(vp_dev->pci_dev, vp_dev->msix_entries, nvectors);
+ if (err > 0)
+ err = -ENOSPC;
+ if (err)
+ goto error;
+ vp_dev->msix_vectors = nvectors;
+ vp_dev->msix_enabled = 1;
+
+ /* Set the vector used for configuration */
+ v = vp_dev->msix_used_vectors;
+ snprintf(vp_dev->msix_names[v], sizeof *vp_dev->msix_names,
+ "%s-config", name);
+ err = request_irq(vp_dev->msix_entries[v].vector,
+ vp_config_changed, 0, vp_dev->msix_names[v],
+ vp_dev);
+ if (err)
+ goto error;
+ ++vp_dev->msix_used_vectors;
+
+ iowrite16(v, &vp_dev->common->msix_config);
+ /* Verify we had enough resources to assign the vector */
+ v = ioread16(&vp_dev->common->msix_config);
+ if (v == VIRTIO_MSI_NO_VECTOR) {
+ err = -EBUSY;
+ goto error;
+ }
+
+ if (!per_vq_vectors) {
+ /* Shared vector for all VQs */
+ v = vp_dev->msix_used_vectors;
+ snprintf(vp_dev->msix_names[v], sizeof *vp_dev->msix_names,
+ "%s-virtqueues", name);
+ err = request_irq(vp_dev->msix_entries[v].vector,
+ vp_vring_interrupt, 0, vp_dev->msix_names[v],
+ vp_dev);
+ if (err)
+ goto error;
+ ++vp_dev->msix_used_vectors;
+ }
+ return 0;
+error:
+ vp_free_vectors(vdev);
+ return err;
+}
+
+static int vp_request_intx(struct virtio_device *vdev)
+{
+ int err;
+ struct virtio_pci_device *vp_dev = to_vp_device(vdev);
+
+ err = request_irq(vp_dev->pci_dev->irq, vp_interrupt,
+ IRQF_SHARED, dev_name(&vdev->dev), vp_dev);
+ if (!err)
+ vp_dev->intx_enabled = 1;
+ return err;
+}
+
+static void *alloc_virtqueue_pages(u16 *num)
+{
+ void *pages;
+
+ /* 1024 entries uses about 32k */
+ if (*num > 1024)
+ *num = 1024;
+
+ for (; *num; *num /= 2) {
+ size_t size = PAGE_ALIGN(vring_size(*num, VIRTIO_PCI_ALIGN));
+ pages = alloc_pages_exact(size,
+ GFP_KERNEL|__GFP_ZERO|__GFP_NOWARN);
+ if (pages)
+ return pages;
+ }
+ return NULL;
+}
+
+static struct virtqueue *setup_vq(struct virtio_device *vdev, unsigned index,
+ void (*callback)(struct virtqueue *vq),
+ const char *name,
+ u16 msix_vec)
+{
+ struct virtio_pci_device *vp_dev = to_vp_device(vdev);
+ struct virtio_pci_vq_info *info;
+ struct virtqueue *vq;
+ u16 num;
+ int err;
+
+ /* Select the queue we're interested in */
+ iowrite16(index, &vp_dev->common->queue_select);
+
+ switch (ioread64(&vp_dev->common->queue_address)) {
+ case 0xFFFFFFFFFFFFFFFFULL:
+ return ERR_PTR(-ENOENT);
+ case 0:
+ /* Uninitialized. Excellent. */
+ break;
+ default:
+ /* We've already set this up? */
+ return ERR_PTR(-EBUSY);
+ }
+
+ /* Maximum size must be a power of 2. */
+ num = ioread16(&vp_dev->common->queue_size);
+ if (num & (num - 1)) {
+ dev_warn(&vp_dev->pci_dev->dev, "bad queue size %u", num);
+ return ERR_PTR(-EINVAL);
+ }
+
+ /* allocate and fill out our structure the represents an active
+ * queue */
+ info = kmalloc(sizeof(struct virtio_pci_vq_info), GFP_KERNEL);
+ if (!info)
+ return ERR_PTR(-ENOMEM);
+
+ info->queue_index = index;
+ info->msix_vector = msix_vec;
+
+ info->queue = alloc_virtqueue_pages(&num);
+ if (info->queue == NULL) {
+ err = -ENOMEM;
+ goto out_info;
+ }
+ info->num = num;
+
+ /* create the vring */
+ vq = vring_new_virtqueue(info->num, VIRTIO_PCI_ALIGN,
+ vdev, info->queue, vp_notify, callback, name);
+ if (!vq) {
+ err = -ENOMEM;
+ goto out_alloc_pages;
+ }
+
+ vq->priv = info;
+ info->vq = vq;
+
+ if (msix_vec != VIRTIO_MSI_NO_VECTOR) {
+ iowrite16(msix_vec, &vp_dev->common->queue_msix_vector);
+ msix_vec = ioread16(&vp_dev->common->queue_msix_vector);
+ if (msix_vec == VIRTIO_MSI_NO_VECTOR) {
+ err = -EBUSY;
+ goto out_new_virtqueue;
+ }
+ }
+
+ if (callback) {
+ unsigned long flags;
+ spin_lock_irqsave(&vp_dev->lock, flags);
+ list_add(&info->node, &vp_dev->virtqueues);
+ spin_unlock_irqrestore(&vp_dev->lock, flags);
+ } else {
+ INIT_LIST_HEAD(&info->node);
+ }
+
+ /* Activate the queue. */
+ iowrite64(virt_to_phys(info->queue), &vp_dev->common->queue_address);
+ iowrite16(VIRTIO_PCI_ALIGN, &vp_dev->common->queue_align);
+ iowrite16(num, &vp_dev->common->queue_size);
+
+ return vq;
+
+out_new_virtqueue:
+ vring_del_virtqueue(vq);
+out_alloc_pages:
+ free_pages_exact(info->queue,
+ PAGE_ALIGN(vring_size(num, VIRTIO_PCI_ALIGN)));
+out_info:
+ kfree(info);
+ return ERR_PTR(err);
+}
+
+static void vp_del_vq(struct virtqueue *vq)
+{
+ struct virtio_pci_device *vp_dev = to_vp_device(vq->vdev);
+ struct virtio_pci_vq_info *info = vq->priv;
+ unsigned long flags, size;
+
+ spin_lock_irqsave(&vp_dev->lock, flags);
+ list_del(&info->node);
+ spin_unlock_irqrestore(&vp_dev->lock, flags);
+
+ /* Select and deactivate the queue */
+ iowrite16(info->queue_index, &vp_dev->common->queue_select);
+
+ if (vp_dev->msix_enabled) {
+ iowrite16(VIRTIO_MSI_NO_VECTOR,
+ &vp_dev->common->queue_msix_vector);
+ /* Flush the write out to device */
+ ioread16(&vp_dev->common->queue_msix_vector);
+ }
+
+ vring_del_virtqueue(vq);
+
+ /* This is for our own benefit, not the device's! */
+ iowrite64(0, &vp_dev->common->queue_address);
+ iowrite16(0, &vp_dev->common->queue_size);
+ iowrite16(0, &vp_dev->common->queue_align);
+
+ size = PAGE_ALIGN(vring_size(info->num, VIRTIO_PCI_ALIGN));
+ free_pages_exact(info->queue, size);
+ kfree(info);
+}
+
+/* the config->del_vqs() implementation */
+static void vp_del_vqs(struct virtio_device *vdev)
+{
+ struct virtio_pci_device *vp_dev = to_vp_device(vdev);
+ struct virtqueue *vq, *n;
+ struct virtio_pci_vq_info *info;
+
+ list_for_each_entry_safe(vq, n, &vdev->vqs, list) {
+ info = vq->priv;
+ if (vp_dev->per_vq_vectors &&
+ info->msix_vector != VIRTIO_MSI_NO_VECTOR)
+ free_irq(vp_dev->msix_entries[info->msix_vector].vector,
+ vq);
+ vp_del_vq(vq);
+ }
+ vp_dev->per_vq_vectors = false;
+
+ vp_free_vectors(vdev);
+}
+
+static int vp_try_to_find_vqs(struct virtio_device *vdev, unsigned nvqs,
+ struct virtqueue *vqs[],
+ vq_callback_t *callbacks[],
+ const char *names[],
+ bool use_msix,
+ bool per_vq_vectors)
+{
+ struct virtio_pci_device *vp_dev = to_vp_device(vdev);
+ u16 msix_vec;
+ int i, err, nvectors, allocated_vectors;
+
+ if (!use_msix) {
+ /* Old style: one normal interrupt for change and all vqs. */
+ err = vp_request_intx(vdev);
+ if (err)
+ goto error_request;
+ } else {
+ if (per_vq_vectors) {
+ /* Best option: one for change interrupt, one per vq. */
+ nvectors = 1;
+ for (i = 0; i < nvqs; ++i)
+ if (callbacks[i])
+ ++nvectors;
+ } else {
+ /* Second best: one for change, shared for all vqs. */
+ nvectors = 2;
+ }
+
+ err = vp_request_msix_vectors(vdev, nvectors, per_vq_vectors);
+ if (err)
+ goto error_request;
+ }
+
+ vp_dev->per_vq_vectors = per_vq_vectors;
+ allocated_vectors = vp_dev->msix_used_vectors;
+ for (i = 0; i < nvqs; ++i) {
+ if (!callbacks[i] || !vp_dev->msix_enabled)
+ msix_vec = VIRTIO_MSI_NO_VECTOR;
+ else if (vp_dev->per_vq_vectors)
+ msix_vec = allocated_vectors++;
+ else
+ msix_vec = VP_MSIX_VQ_VECTOR;
+ vqs[i] = setup_vq(vdev, i, callbacks[i], names[i], msix_vec);
+ if (IS_ERR(vqs[i])) {
+ err = PTR_ERR(vqs[i]);
+ goto error_find;
+ }
+
+ if (!vp_dev->per_vq_vectors || msix_vec == VIRTIO_MSI_NO_VECTOR)
+ continue;
+
+ /* allocate per-vq irq if available and necessary */
+ snprintf(vp_dev->msix_names[msix_vec],
+ sizeof *vp_dev->msix_names,
+ "%s-%s",
+ dev_name(&vp_dev->vdev.dev), names[i]);
+ err = request_irq(vp_dev->msix_entries[msix_vec].vector,
+ vring_interrupt, 0,
+ vp_dev->msix_names[msix_vec],
+ vqs[i]);
+ if (err) {
+ vp_del_vq(vqs[i]);
+ goto error_find;
+ }
+ }
+ return 0;
+
+error_find:
+ vp_del_vqs(vdev);
+
+error_request:
+ return err;
+}
+
+/* the config->find_vqs() implementation */
+static int vp_find_vqs(struct virtio_device *vdev, unsigned nvqs,
+ struct virtqueue *vqs[],
+ vq_callback_t *callbacks[],
+ const char *names[])
+{
+ int err;
+
+ /* Try MSI-X with one vector per queue. */
+ err = vp_try_to_find_vqs(vdev, nvqs, vqs, callbacks, names, true, true);
+ if (!err)
+ return 0;
+ /* Fallback: MSI-X with one vector for config, one shared for queues. */
+ err = vp_try_to_find_vqs(vdev, nvqs, vqs, callbacks, names,
+ true, false);
+ if (!err)
+ return 0;
+ /* Finally fall back to regular interrupts. */
+ return vp_try_to_find_vqs(vdev, nvqs, vqs, callbacks, names,
+ false, false);
+}
+
+static 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,
+};
+
+static void virtio_pci_release_dev(struct device *_d)
+{
+ /*
+ * No need for a release method as we allocate/free
+ * all devices together with the pci devices.
+ * Provide an empty one to avoid getting a warning from core.
+ */
+}
+
+static void __iomem *map_capability(struct pci_dev *dev, int off, size_t
expect)
+{
+ u8 bar;
+ u32 offset, length;
+ void __iomem *p;
+
+ pci_read_config_byte(dev, off + offsetof(struct virtio_pci_cap, bar),
+ &bar);
+ pci_read_config_dword(dev, off + offsetof(struct virtio_pci_cap,
offset),
+ &offset);
+ pci_read_config_dword(dev, off + offsetof(struct virtio_pci_cap,
length),
+ &length);
+
+ if (length < expect) {
+ /* FIXME: I assume we want to report errors as PCI device? */
+ dev_err(&dev->dev,
+ "virtio_pci: small capability len %u (%u expected)\n",
+ length, expect);
+ return NULL;
+ }
+
+ p = pci_iomap_range(dev, bar, offset, length, PAGE_SIZE);
+ if (!p)
+ /* FIXME: I assume we want to report errors as PCI device? */
+ dev_err(&dev->dev,
+ "virtio_pci: unable to map virtio %u@%u on bar %i\n",
+ length, offset, bar);
+ return p;
+}
+
+
+/* the PCI probing function */
+static int __devinit virtio_pci_probe(struct pci_dev *pci_dev,
+ const struct pci_device_id *id)
+{
+ struct virtio_pci_device *vp_dev;
+ int err, common, isr, notify, device;
+
+ /* 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;
+
+ /* check for a legacy bar0 device. */
+ common = virtio_pci_find_capability(pci_dev, VIRTIO_PCI_CAP_COMMON_CFG);
+ if (!common) {
+ dev_info(&pci_dev->dev,
+ "virtio_pci: leaving for legacy driver\n");
+ err = -ENODEV;
+ goto out_enable_device;
+ }
+ isr = virtio_pci_find_capability(pci_dev, VIRTIO_PCI_CAP_ISR_CFG);
+ notify = virtio_pci_find_capability(pci_dev, VIRTIO_PCI_CAP_NOTIFY_CFG);
+ device = virtio_pci_find_capability(pci_dev, VIRTIO_PCI_CAP_DEVICE_CFG);
+ if (!isr || !notify || !device) {
+ dev_err(&pci_dev->dev,
+ "virtio_pci: missing capabilities %i/%i/%i/%i\n",
+ common, isr, notify, device);
+ goto out_enable_device;
+ }
+
+ err = pci_request_regions(pci_dev, "virtio-pci");
+ if (err)
+ goto out_enable_device;
+
+ vp_dev->common = map_capability(pci_dev, common,
+ sizeof(struct virtio_pci_common_cfg));
+ if (!vp_dev->common)
+ goto out_req_regions;
+ vp_dev->isr = map_capability(pci_dev, isr, sizeof(u8));
+ if (!vp_dev->isr)
+ goto out_map_common;
+ vp_dev->notify = map_capability(pci_dev, notify, sizeof(u16));
+ if (!vp_dev->notify)
+ goto out_map_isr;
+ vp_dev->device = map_capability(pci_dev, device, 0);
+ if (!vp_dev->device)
+ goto out_map_notify;
+
+ 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;
+
+ /* finally register the virtio device */
+ err = register_virtio_device(&vp_dev->vdev);
+ if (err)
+ goto out_set_drvdata;
+
+ return 0;
+
+out_set_drvdata:
+ pci_set_drvdata(pci_dev, NULL);
+ pci_iounmap(pci_dev, vp_dev->device);
+out_map_notify:
+ pci_iounmap(pci_dev, vp_dev->notify);
+out_map_isr:
+ pci_iounmap(pci_dev, vp_dev->isr);
+out_map_common:
+ pci_iounmap(pci_dev, vp_dev->common);
+out_req_regions:
+ pci_release_regions(pci_dev);
+out_enable_device:
+ pci_disable_device(pci_dev);
+out:
+ kfree(vp_dev);
+ return err;
+}
+
+static void __devexit 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_set_drvdata(pci_dev, NULL);
+ pci_iounmap(pci_dev, vp_dev->device);
+ pci_iounmap(pci_dev, vp_dev->notify);
+ pci_iounmap(pci_dev, vp_dev->isr);
+ pci_iounmap(pci_dev, vp_dev->common);
+ pci_release_regions(pci_dev);
+ pci_disable_device(pci_dev);
+ kfree(vp_dev);
+}
+
+#ifdef CONFIG_PM
+static int virtio_pci_suspend(struct pci_dev *pci_dev, pm_message_t state)
+{
+ pci_save_state(pci_dev);
+ pci_set_power_state(pci_dev, PCI_D3hot);
+ return 0;
+}
+
+static int virtio_pci_resume(struct pci_dev *pci_dev)
+{
+ pci_restore_state(pci_dev);
+ pci_set_power_state(pci_dev, PCI_D0);
+ return 0;
+}
+#endif
+
+static struct pci_driver virtio_pci_driver = {
+ .name = "virtio-pci",
+ .id_table = virtio_pci_id_table,
+ .probe = virtio_pci_probe,
+ .remove = __devexit_p(virtio_pci_remove),
+#ifdef CONFIG_PM
+ .suspend = virtio_pci_suspend,
+ .resume = virtio_pci_resume,
+#endif
+};
+
+static int __init virtio_pci_init(void)
+{
+ return pci_register_driver(&virtio_pci_driver);
+}
+
+module_init(virtio_pci_init);
+
+static void __exit virtio_pci_exit(void)
+{
+ pci_unregister_driver(&virtio_pci_driver);
+}
+
+module_exit(virtio_pci_exit);
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