drivers/virtio/virtio_pci_common.h

   1 #ifndef _DRIVERS_VIRTIO_VIRTIO_PCI_COMMON_H
   2 #define _DRIVERS_VIRTIO_VIRTIO_PCI_COMMON_H
   3 /*
   4  * Virtio PCI driver - APIs for common functionality for all device versions
   5  *
   6  * This module allows virtio devices to be used over a virtual PCI device.
   7  * This can be used with QEMU based VMMs like KVM or Xen.
   8  *
   9  * Copyright IBM Corp. 2007
  10  * Copyright Red Hat, Inc. 2014
  11  *
  12  * Authors:
  13  *  Anthony Liguori  <aliguori@us.ibm.com>
  14  *  Rusty Russell <rusty@rustcorp.com.au>
  15  *  Michael S. Tsirkin <mst@redhat.com>
  16  *
  17  * This work is licensed under the terms of the GNU GPL, version 2 or later.
  18  * See the COPYING file in the top-level directory.
  19  *
  20  */
  21
  22 #include <linux/module.h>
  23 #include <linux/list.h>
  24 #include <linux/pci.h>
  25 #include <linux/slab.h>
  26 #include <linux/interrupt.h>
  27 #include <linux/virtio.h>
  28 #include <linux/virtio_config.h>
  29 #include <linux/virtio_ring.h>
  30 #include <linux/virtio_pci.h>
  31 #include <linux/highmem.h>
  32 #include <linux/spinlock.h>
  33
  34 struct virtio_pci_vq_info {
  35         /* the actual virtqueue */
  36         struct virtqueue *vq;
  37
  38         /* the number of entries in the queue */
  39         int num;
  40
  41         /* the virtual address of the ring queue */
  42         void *queue;
  43
  44         /* the list node for the virtqueues list */
  45         struct list_head node;
  46
  47         /* MSI-X vector (or none) */
  48         unsigned msix_vector;
  49 };
  50
  51 /* Our device structure */
  52 struct virtio_pci_device {
  53         struct virtio_device vdev;
  54         struct pci_dev *pci_dev;
  55
  56         /* the IO mapping for the PCI config space */
  57         void __iomem *ioaddr;
  58
  59         /* the IO mapping for ISR operation */
  60         void __iomem *isr;
  61
  62         /* a list of queues so we can dispatch IRQs */
  63         spinlock_t lock;
  64         struct list_head virtqueues;
  65
  66         /* array of all queues for house-keeping */
  67         struct virtio_pci_vq_info **vqs;
  68
  69         /* MSI-X support */
  70         int msix_enabled;
  71         int intx_enabled;
  72         struct msix_entry *msix_entries;
  73         cpumask_var_t *msix_affinity_masks;
  74         /* Name strings for interrupts. This size should be enough,
  75          * and I'm too lazy to allocate each name separately. */
  76         char (*msix_names)[256];
  77         /* Number of available vectors */
  78         unsigned msix_vectors;
  79         /* Vectors allocated, excluding per-vq vectors if any */
  80         unsigned msix_used_vectors;
  81
  82         /* Whether we have vector per vq */
  83         bool per_vq_vectors;
  84
  85         struct virtqueue *(*setup_vq)(struct virtio_pci_device *vp_dev,
  86                                       struct virtio_pci_vq_info *info,
  87                                       unsigned idx,
  88                                       void (*callback)(struct virtqueue *vq),
  89                                       const char *name,
  90                                       u16 msix_vec);
  91         void (*del_vq)(struct virtio_pci_vq_info *info);
  92
  93         u16 (*config_vector)(struct virtio_pci_device *vp_dev, u16 vector);
  94 };
  95
  96 /* Constants for MSI-X */
  97 /* Use first vector for configuration changes, second and the rest for
  98  * virtqueues Thus, we need at least 2 vectors for MSI. */
  99 enum {
 100         VP_MSIX_CONFIG_VECTOR = 0,
 101         VP_MSIX_VQ_VECTOR = 1,
 102 };
 103
 104 /* Convert a generic virtio device to our structure */
 105 static struct virtio_pci_device *to_vp_device(struct virtio_device *vdev)
 106 {
 107         return container_of(vdev, struct virtio_pci_device, vdev);
 108 }
 109
 110 /* wait for pending irq handlers */
 111 void vp_synchronize_vectors(struct virtio_device *vdev);
 112 /* the notify function used when creating a virt queue */
 113 bool vp_notify(struct virtqueue *vq);
 114 /* the config->del_vqs() implementation */
 115 void vp_del_vqs(struct virtio_device *vdev);
 116 /* the config->find_vqs() implementation */
 117 int vp_find_vqs(struct virtio_device *vdev, unsigned nvqs,
 118                        struct virtqueue *vqs[],
 119                        vq_callback_t *callbacks[],
 120                        const char *names[]);
 121 const char *vp_bus_name(struct virtio_device *vdev);
 122
 123 /* Setup the affinity for a virtqueue:
 124  * - force the affinity for per vq vector
 125  * - OR over all affinities for shared MSI
 126  * - ignore the affinity request if we're using INTX
 127  */
 128 int vp_set_vq_affinity(struct virtqueue *vq, int cpu);
 129 void virtio_pci_release_dev(struct device *);
 130
 131 int virtio_pci_legacy_probe(struct pci_dev *pci_dev,
 132                             const struct pci_device_id *id);
 133 void virtio_pci_legacy_remove(struct pci_dev *pci_dev);
 134
 135 #endif