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/highmem.h>
  29 #include <linux/spinlock.h>
  30
  31 struct virtio_pci_vq_info {
  32         /* the actual virtqueue */
  33         struct virtqueue *vq;
  34
  35         /* the list node for the virtqueues list */
  36         struct list_head node;
  37
  38         /* MSI-X vector (or none) */
  39         unsigned msix_vector;
  40 };
  41
  42 /* Our device structure */
  43 struct virtio_pci_device {
  44         struct virtio_device vdev;
  45         struct pci_dev *pci_dev;
  46
  47         /* In legacy mode, these two point to within ->legacy. */
  48         /* Where to read and clear interrupt */
  49         u8 __iomem *isr;
  50
  51         /* Modern only fields */
  52         /* The IO mapping for the PCI config space (non-legacy mode) */
  53         struct virtio_pci_common_cfg __iomem *common;
  54         /* Device-specific data (non-legacy mode)  */
  55         void __iomem *device;
  56         /* Base of vq notifications (non-legacy mode). */
  57         void __iomem *notify_base;
  58
  59         /* So we can sanity-check accesses. */
  60         size_t notify_len;
  61         size_t device_len;
  62
  63         /* Capability for when we need to map notifications per-vq. */
  64         int notify_map_cap;
  65
  66         /* Multiply queue_notify_off by this value. (non-legacy mode). */
  67         u32 notify_offset_multiplier;
  68
  69         int modern_bars;
  70
  71         /* Legacy only field */
  72         /* the IO mapping for the PCI config space */
  73         void __iomem *ioaddr;
  74
  75         /* a list of queues so we can dispatch IRQs */
  76         spinlock_t lock;
  77         struct list_head virtqueues;
  78
  79         /* array of all queues for house-keeping */
  80         struct virtio_pci_vq_info **vqs;
  81
  82         /* MSI-X support */
  83         int msix_enabled;
  84         int intx_enabled;
  85         cpumask_var_t *msix_affinity_masks;
  86         /* Name strings for interrupts. This size should be enough,
  87          * and I'm too lazy to allocate each name separately. */
  88         char (*msix_names)[256];
  89         /* Number of available vectors */
  90         unsigned msix_vectors;
  91         /* Vectors allocated, excluding per-vq vectors if any */
  92         unsigned msix_used_vectors;
  93
  94         /* Whether we have vector per vq */
  95         bool per_vq_vectors;
  96
  97         struct virtqueue *(*setup_vq)(struct virtio_pci_device *vp_dev,
  98                                       struct virtio_pci_vq_info *info,
  99                                       unsigned idx,
 100                                       void (*callback)(struct virtqueue *vq),
 101                                       const char *name,
 102                                       bool ctx,
 103                                       u16 msix_vec);
 104         void (*del_vq)(struct virtio_pci_vq_info *info);
 105
 106         u16 (*config_vector)(struct virtio_pci_device *vp_dev, u16 vector);
 107 };
 108
 109 /* Constants for MSI-X */
 110 /* Use first vector for configuration changes, second and the rest for
 111  * virtqueues Thus, we need at least 2 vectors for MSI. */
 112 enum {
 113         VP_MSIX_CONFIG_VECTOR = 0,
 114         VP_MSIX_VQ_VECTOR = 1,
 115 };
 116
 117 /* Convert a generic virtio device to our structure */
 118 static struct virtio_pci_device *to_vp_device(struct virtio_device *vdev)
 119 {
 120         return container_of(vdev, struct virtio_pci_device, vdev);
 121 }
 122
 123 /* wait for pending irq handlers */
 124 void vp_synchronize_vectors(struct virtio_device *vdev);
 125 /* the notify function used when creating a virt queue */
 126 bool vp_notify(struct virtqueue *vq);
 127 /* the config->del_vqs() implementation */
 128 void vp_del_vqs(struct virtio_device *vdev);
 129 /* the config->find_vqs() implementation */
 130 int vp_find_vqs(struct virtio_device *vdev, unsigned nvqs,
 131                 struct virtqueue *vqs[], vq_callback_t *callbacks[],
 132                 const char * const names[], const bool *ctx,
 133                 struct irq_affinity *desc);
 134 const char *vp_bus_name(struct virtio_device *vdev);
 135
 136 /* Setup the affinity for a virtqueue:
 137  * - force the affinity for per vq vector
 138  * - OR over all affinities for shared MSI
 139  * - ignore the affinity request if we're using INTX
 140  */
 141 int vp_set_vq_affinity(struct virtqueue *vq, const struct cpumask *cpu_mask);
 142
 143 const struct cpumask *vp_get_vq_affinity(struct virtio_device *vdev, int index);
 144
 145 #if IS_ENABLED(CONFIG_VIRTIO_PCI_LEGACY)
 146 int virtio_pci_legacy_probe(struct virtio_pci_device *);
 147 void virtio_pci_legacy_remove(struct virtio_pci_device *);
 148 #else
 149 static inline int virtio_pci_legacy_probe(struct virtio_pci_device *vp_dev)
 150 {
 151         return -ENODEV;
 152 }
 153 static inline void virtio_pci_legacy_remove(struct virtio_pci_device *vp_dev)
 154 {
 155 }
 156 #endif
 157 int virtio_pci_modern_probe(struct virtio_pci_device *);
 158 void virtio_pci_modern_remove(struct virtio_pci_device *);
 159
 160 #endif