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 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 */
  52struct virtio_pci_device {
  53        struct virtio_device vdev;
  54        struct pci_dev *pci_dev;
  55
  56        /* In legacy mode, these two point to within ->legacy. */
  57        /* Where to read and clear interrupt */
  58        u8 __iomem *isr;
  59
  60        /* Modern only fields */
  61        /* The IO mapping for the PCI config space (non-legacy mode) */
  62        struct virtio_pci_common_cfg __iomem *common;
  63        /* Device-specific data (non-legacy mode)  */
  64        void __iomem *device;
  65        /* Base of vq notifications (non-legacy mode). */
  66        void __iomem *notify_base;
  67
  68        /* So we can sanity-check accesses. */
  69        size_t notify_len;
  70        size_t device_len;
  71
  72        /* Capability for when we need to map notifications per-vq. */
  73        int notify_map_cap;
  74
  75        /* Multiply queue_notify_off by this value. (non-legacy mode). */
  76        u32 notify_offset_multiplier;
  77
  78        int modern_bars;
  79
  80        /* Legacy only field */
  81        /* the IO mapping for the PCI config space */
  82        void __iomem *ioaddr;
  83
  84        /* a list of queues so we can dispatch IRQs */
  85        spinlock_t lock;
  86        struct list_head virtqueues;
  87
  88        /* array of all queues for house-keeping */
  89        struct virtio_pci_vq_info **vqs;
  90
  91        /* MSI-X support */
  92        int msix_enabled;
  93        int intx_enabled;
  94        struct msix_entry *msix_entries;
  95        cpumask_var_t *msix_affinity_masks;
  96        /* Name strings for interrupts. This size should be enough,
  97         * and I'm too lazy to allocate each name separately. */
  98        char (*msix_names)[256];
  99        /* Number of available vectors */
 100        unsigned msix_vectors;
 101        /* Vectors allocated, excluding per-vq vectors if any */
 102        unsigned msix_used_vectors;
 103
 104        /* Whether we have vector per vq */
 105        bool per_vq_vectors;
 106
 107        struct virtqueue *(*setup_vq)(struct virtio_pci_device *vp_dev,
 108                                      struct virtio_pci_vq_info *info,
 109                                      unsigned idx,
 110                                      void (*callback)(struct virtqueue *vq),
 111                                      const char *name,
 112                                      u16 msix_vec);
 113        void (*del_vq)(struct virtio_pci_vq_info *info);
 114
 115        u16 (*config_vector)(struct virtio_pci_device *vp_dev, u16 vector);
 116};
 117
 118/* Constants for MSI-X */
 119/* Use first vector for configuration changes, second and the rest for
 120 * virtqueues Thus, we need at least 2 vectors for MSI. */
 121enum {
 122        VP_MSIX_CONFIG_VECTOR = 0,
 123        VP_MSIX_VQ_VECTOR = 1,
 124};
 125
 126/* Convert a generic virtio device to our structure */
 127static struct virtio_pci_device *to_vp_device(struct virtio_device *vdev)
 128{
 129        return container_of(vdev, struct virtio_pci_device, vdev);
 130}
 131
 132/* wait for pending irq handlers */
 133void vp_synchronize_vectors(struct virtio_device *vdev);
 134/* the notify function used when creating a virt queue */
 135bool vp_notify(struct virtqueue *vq);
 136/* the config->del_vqs() implementation */
 137void vp_del_vqs(struct virtio_device *vdev);
 138/* the config->find_vqs() implementation */
 139int vp_find_vqs(struct virtio_device *vdev, unsigned nvqs,
 140                       struct virtqueue *vqs[],
 141                       vq_callback_t *callbacks[],
 142                       const char *names[]);
 143const char *vp_bus_name(struct virtio_device *vdev);
 144
 145/* Setup the affinity for a virtqueue:
 146 * - force the affinity for per vq vector
 147 * - OR over all affinities for shared MSI
 148 * - ignore the affinity request if we're using INTX
 149 */
 150int vp_set_vq_affinity(struct virtqueue *vq, int cpu);
 151
 152#if IS_ENABLED(CONFIG_VIRTIO_PCI_LEGACY)
 153int virtio_pci_legacy_probe(struct virtio_pci_device *);
 154void virtio_pci_legacy_remove(struct virtio_pci_device *);
 155#else
 156static inline int virtio_pci_legacy_probe(struct virtio_pci_device *vp_dev)
 157{
 158        return -ENODEV;
 159}
 160static inline void virtio_pci_legacy_remove(struct virtio_pci_device *vp_dev)
 161{
 162}
 163#endif
 164int virtio_pci_modern_probe(struct virtio_pci_device *);
 165void virtio_pci_modern_remove(struct virtio_pci_device *);
 166
 167#endif
 168