drivers/virtio/virtio_pci_common.h

   1 /* SPDX-License-Identifier: GPL-2.0-or-later */
   2 #ifndef _DRIVERS_VIRTIO_VIRTIO_PCI_COMMON_H
   3 #define _DRIVERS_VIRTIO_VIRTIO_PCI_COMMON_H
   4 /*
   5  * Virtio PCI driver - APIs for common functionality for all device versions
   6  *
   7  * This module allows virtio devices to be used over a virtual PCI device.
   8  * This can be used with QEMU based VMMs like KVM or Xen.
   9  *
  10  * Copyright IBM Corp. 2007
  11  * Copyright Red Hat, Inc. 2014
  12  *
  13  * Authors:
  14  *  Anthony Liguori  <aliguori@us.ibm.com>
  15  *  Rusty Russell <rusty@rustcorp.com.au>
  16  *  Michael S. Tsirkin <mst@redhat.com>
  17  */
  18
  19 #include <linux/module.h>
  20 #include <linux/list.h>
  21 #include <linux/pci.h>
  22 #include <linux/slab.h>
  23 #include <linux/interrupt.h>
  24 #include <linux/virtio.h>
  25 #include <linux/virtio_config.h>
  26 #include <linux/virtio_ring.h>
  27 #include <linux/virtio_pci.h>
  28 #include <linux/virtio_pci_modern.h>
  29 #include <linux/highmem.h>
  30 #include <linux/spinlock.h>
  31
  32 struct virtio_pci_vq_info {
  33         /* the actual virtqueue */
  34         struct virtqueue *vq;
  35
  36         /* the list node for the virtqueues list */
  37         struct list_head node;
  38
  39         /* MSI-X vector (or none) */
  40         unsigned msix_vector;
  41 };
  42
  43 /* Our device structure */
  44 struct virtio_pci_device {
  45         struct virtio_device vdev;
  46         struct pci_dev *pci_dev;
  47         struct virtio_pci_modern_device mdev;
  48
  49         /* In legacy mode, these two point to within ->legacy. */
  50         /* Where to read and clear interrupt */
  51         u8 __iomem *isr;
  52
  53         /* Legacy only field */
  54         /* the IO mapping for the PCI config space */
  55         void __iomem *ioaddr;
  56
  57         /* a list of queues so we can dispatch IRQs */
  58         spinlock_t lock;
  59         struct list_head virtqueues;
  60
  61         /* array of all queues for house-keeping */
  62         struct virtio_pci_vq_info **vqs;
  63
  64         /* MSI-X support */
  65         int msix_enabled;
  66         int intx_enabled;
  67         cpumask_var_t *msix_affinity_masks;
  68         /* Name strings for interrupts. This size should be enough,
  69          * and I'm too lazy to allocate each name separately. */
  70         char (*msix_names)[256];
  71         /* Number of available vectors */
  72         unsigned msix_vectors;
  73         /* Vectors allocated, excluding per-vq vectors if any */
  74         unsigned msix_used_vectors;
  75
  76         /* Whether we have vector per vq */
  77         bool per_vq_vectors;
  78
  79         struct virtqueue *(*setup_vq)(struct virtio_pci_device *vp_dev,
  80                                       struct virtio_pci_vq_info *info,
  81                                       unsigned idx,
  82                                       void (*callback)(struct virtqueue *vq),
  83                                       const char *name,
  84                                       bool ctx,
  85                                       u16 msix_vec);
  86         void (*del_vq)(struct virtio_pci_vq_info *info);
  87
  88         u16 (*config_vector)(struct virtio_pci_device *vp_dev, u16 vector);
  89 };
  90
  91 /* Constants for MSI-X */
  92 /* Use first vector for configuration changes, second and the rest for
  93  * virtqueues Thus, we need at least 2 vectors for MSI. */
  94 enum {
  95         VP_MSIX_CONFIG_VECTOR = 0,
  96         VP_MSIX_VQ_VECTOR = 1,
  97 };
  98
  99 /* Convert a generic virtio device to our structure */
 100 static struct virtio_pci_device *to_vp_device(struct virtio_device *vdev)
 101 {
 102         return container_of(vdev, struct virtio_pci_device, vdev);
 103 }
 104
 105 /* wait for pending irq handlers */
 106 void vp_synchronize_vectors(struct virtio_device *vdev);
 107 /* the notify function used when creating a virt queue */
 108 bool vp_notify(struct virtqueue *vq);
 109 /* the config->del_vqs() implementation */
 110 void vp_del_vqs(struct virtio_device *vdev);
 111 /* the config->find_vqs() implementation */
 112 int vp_find_vqs(struct virtio_device *vdev, unsigned nvqs,
 113                 struct virtqueue *vqs[], vq_callback_t *callbacks[],
 114                 const char * const names[], const bool *ctx,
 115                 struct irq_affinity *desc);
 116 const char *vp_bus_name(struct virtio_device *vdev);
 117
 118 /* Setup the affinity for a virtqueue:
 119  * - force the affinity for per vq vector
 120  * - OR over all affinities for shared MSI
 121  * - ignore the affinity request if we're using INTX
 122  */
 123 int vp_set_vq_affinity(struct virtqueue *vq, const struct cpumask *cpu_mask);
 124
 125 const struct cpumask *vp_get_vq_affinity(struct virtio_device *vdev, int index);
 126
 127 #if IS_ENABLED(CONFIG_VIRTIO_PCI_LEGACY)
 128 int virtio_pci_legacy_probe(struct virtio_pci_device *);
 129 void virtio_pci_legacy_remove(struct virtio_pci_device *);
 130 #else
 131 static inline int virtio_pci_legacy_probe(struct virtio_pci_device *vp_dev)
 132 {
 133         return -ENODEV;
 134 }
 135 static inline void virtio_pci_legacy_remove(struct virtio_pci_device *vp_dev)
 136 {
 137 }
 138 #endif
 139 int virtio_pci_modern_probe(struct virtio_pci_device *);
 140 void virtio_pci_modern_remove(struct virtio_pci_device *);
 141
 142 #endif