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 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 */
  52 struct 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. */
 121 enum {
 122         VP_MSIX_CONFIG_VECTOR = 0,
 123         VP_MSIX_VQ_VECTOR = 1,
 124 };
 125
 126 /* Convert a generic virtio device to our structure */
 127 static 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 */
 133 void vp_synchronize_vectors(struct virtio_device *vdev);
 134 /* the notify function used when creating a virt queue */
 135 bool vp_notify(struct virtqueue *vq);
 136 /* the config->del_vqs() implementation */
 137 void vp_del_vqs(struct virtio_device *vdev);
 138 /* the config->find_vqs() implementation */
 139 int vp_find_vqs(struct virtio_device *vdev, unsigned nvqs,
 140                        struct virtqueue *vqs[],
 141                        vq_callback_t *callbacks[],
 142                        const char *names[]);
 143 const 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  */
 150 int vp_set_vq_affinity(struct virtqueue *vq, int cpu);
 151
 152 #if IS_ENABLED(CONFIG_VIRTIO_PCI_LEGACY)
 153 int virtio_pci_legacy_probe(struct virtio_pci_device *);
 154 void virtio_pci_legacy_remove(struct virtio_pci_device *);
 155 #else
 156 static inline int virtio_pci_legacy_probe(struct virtio_pci_device *vp_dev)
 157 {
 158         return -ENODEV;
 159 }
 160 static inline void virtio_pci_legacy_remove(struct virtio_pci_device *vp_dev)
 161 {
 162 }
 163 #endif
 164 int virtio_pci_modern_probe(struct virtio_pci_device *);
 165 void virtio_pci_modern_remove(struct virtio_pci_device *);
 166
 167 #endif