LXR linux/drivers/virtio/virtio_pci

   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
  34struct virtio_pci_vq_info {
  35        /* the actual virtqueue */
  36        struct virtqueue *vq;
  37
  38        /* the list node for the virtqueues list */
  39        struct list_head node;
  40
  41        /* MSI-X vector (or none) */
  42        unsigned msix_vector;
  43};
  44
  45/* Our device structure */
  46struct virtio_pci_device {
  47        struct virtio_device vdev;
  48        struct pci_dev *pci_dev;
  49
  50        /* In legacy mode, these two point to within ->legacy. */
  51        /* Where to read and clear interrupt */
  52        u8 __iomem *isr;
  53
  54        /* Modern only fields */
  55        /* The IO mapping for the PCI config space (non-legacy mode) */
  56        struct virtio_pci_common_cfg __iomem *common;
  57        /* Device-specific data (non-legacy mode)  */
  58        void __iomem *device;
  59        /* Base of vq notifications (non-legacy mode). */
  60        void __iomem *notify_base;
  61
  62        /* So we can sanity-check accesses. */
  63        size_t notify_len;
  64        size_t device_len;
  65
  66        /* Capability for when we need to map notifications per-vq. */
  67        int notify_map_cap;
  68
  69        /* Multiply queue_notify_off by this value. (non-legacy mode). */
  70        u32 notify_offset_multiplier;
  71
  72        int modern_bars;
  73
  74        /* Legacy only field */
  75        /* the IO mapping for the PCI config space */
  76        void __iomem *ioaddr;
  77
  78        /* a list of queues so we can dispatch IRQs */
  79        spinlock_t lock;
  80        struct list_head virtqueues;
  81
  82        /* array of all queues for house-keeping */
  83        struct virtio_pci_vq_info **vqs;
  84
  85        /* MSI-X support */
  86        int msix_enabled;
  87        int intx_enabled;
  88        struct msix_entry *msix_entries;
  89        cpumask_var_t *msix_affinity_masks;
  90        /* Name strings for interrupts. This size should be enough,
  91         * and I'm too lazy to allocate each name separately. */
  92        char (*msix_names)[256];
  93        /* Number of available vectors */
  94        unsigned msix_vectors;
  95        /* Vectors allocated, excluding per-vq vectors if any */
  96        unsigned msix_used_vectors;
  97
  98        /* Whether we have vector per vq */
  99        bool per_vq_vectors;
 100
 101        struct virtqueue *(*setup_vq)(struct virtio_pci_device *vp_dev,
 102                                      struct virtio_pci_vq_info *info,
 103                                      unsigned idx,
 104                                      void (*callback)(struct virtqueue *vq),
 105                                      const char *name,
 106                                      u16 msix_vec);
 107        void (*del_vq)(struct virtio_pci_vq_info *info);
 108
 109        u16 (*config_vector)(struct virtio_pci_device *vp_dev, u16 vector);
 110};
 111
 112/* Constants for MSI-X */
 113/* Use first vector for configuration changes, second and the rest for
 114 * virtqueues Thus, we need at least 2 vectors for MSI. */
 115enum {
 116        VP_MSIX_CONFIG_VECTOR = 0,
 117        VP_MSIX_VQ_VECTOR = 1,
 118};
 119
 120/* Convert a generic virtio device to our structure */
 121static struct virtio_pci_device *to_vp_device(struct virtio_device *vdev)
 122{
 123        return container_of(vdev, struct virtio_pci_device, vdev);
 124}
 125
 126/* wait for pending irq handlers */
 127void vp_synchronize_vectors(struct virtio_device *vdev);
 128/* the notify function used when creating a virt queue */
 129bool vp_notify(struct virtqueue *vq);
 130/* the config->del_vqs() implementation */
 131void vp_del_vqs(struct virtio_device *vdev);
 132/* the config->find_vqs() implementation */
 133int vp_find_vqs(struct virtio_device *vdev, unsigned nvqs,
 134                       struct virtqueue *vqs[],
 135                       vq_callback_t *callbacks[],
 136                       const char * const names[]);
 137const char *vp_bus_name(struct virtio_device *vdev);
 138
 139/* Setup the affinity for a virtqueue:
 140 * - force the affinity for per vq vector
 141 * - OR over all affinities for shared MSI
 142 * - ignore the affinity request if we're using INTX
 143 */
 144int vp_set_vq_affinity(struct virtqueue *vq, int cpu);
 145
 146#if IS_ENABLED(CONFIG_VIRTIO_PCI_LEGACY)
 147int virtio_pci_legacy_probe(struct virtio_pci_device *);
 148void virtio_pci_legacy_remove(struct virtio_pci_device *);
 149#else
 150static inline int virtio_pci_legacy_probe(struct virtio_pci_device *vp_dev)
 151{
 152        return -ENODEV;
 153}
 154static inline void virtio_pci_legacy_remove(struct virtio_pci_device *vp_dev)
 155{
 156}
 157#endif
 158int virtio_pci_modern_probe(struct virtio_pci_device *);
 159void virtio_pci_modern_remove(struct virtio_pci_device *);
 160
 161#endif
 162