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 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 */
  46 struct 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         cpumask_var_t *msix_affinity_masks;
  89         /* Name strings for interrupts. This size should be enough,
  90          * and I'm too lazy to allocate each name separately. */
  91         char (*msix_names)[256];
  92         /* Number of available vectors */
  93         unsigned msix_vectors;
  94         /* Vectors allocated, excluding per-vq vectors if any */
  95         unsigned msix_used_vectors;
  96
  97         /* Whether we have vector per vq */
  98         bool per_vq_vectors;
  99
 100         struct virtqueue *(*setup_vq)(struct virtio_pci_device *vp_dev,
 101                                       struct virtio_pci_vq_info *info,
 102                                       unsigned idx,
 103                                       void (*callback)(struct virtqueue *vq),
 104                                       const char *name,
 105                                       bool ctx,
 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. */
 115 enum {
 116         VP_MSIX_CONFIG_VECTOR = 0,
 117         VP_MSIX_VQ_VECTOR = 1,
 118 };
 119
 120 /* Convert a generic virtio device to our structure */
 121 static 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 */
 127 void vp_synchronize_vectors(struct virtio_device *vdev);
 128 /* the notify function used when creating a virt queue */
 129 bool vp_notify(struct virtqueue *vq);
 130 /* the config->del_vqs() implementation */
 131 void vp_del_vqs(struct virtio_device *vdev);
 132 /* the config->find_vqs() implementation */
 133 int vp_find_vqs(struct virtio_device *vdev, unsigned nvqs,
 134                 struct virtqueue *vqs[], vq_callback_t *callbacks[],
 135                 const char * const names[], const bool *ctx,
 136                 struct irq_affinity *desc);
 137 const 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  */
 144 int vp_set_vq_affinity(struct virtqueue *vq, int cpu);
 145
 146 const struct cpumask *vp_get_vq_affinity(struct virtio_device *vdev, int index);
 147
 148 #if IS_ENABLED(CONFIG_VIRTIO_PCI_LEGACY)
 149 int virtio_pci_legacy_probe(struct virtio_pci_device *);
 150 void virtio_pci_legacy_remove(struct virtio_pci_device *);
 151 #else
 152 static inline int virtio_pci_legacy_probe(struct virtio_pci_device *vp_dev)
 153 {
 154         return -ENODEV;
 155 }
 156 static inline void virtio_pci_legacy_remove(struct virtio_pci_device *vp_dev)
 157 {
 158 }
 159 #endif
 160 int virtio_pci_modern_probe(struct virtio_pci_device *);
 161 void virtio_pci_modern_remove(struct virtio_pci_device *);
 162
 163 #endif