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 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 */
 46struct 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. */
115enum {
116	VP_MSIX_CONFIG_VECTOR = 0,
117	VP_MSIX_VQ_VECTOR = 1,
118};
119
120/* Convert a generic virtio device to our structure */
121static 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 */
127void vp_synchronize_vectors(struct virtio_device *vdev);
128/* the notify function used when creating a virt queue */
129bool vp_notify(struct virtqueue *vq);
130/* the config->del_vqs() implementation */
131void vp_del_vqs(struct virtio_device *vdev);
132/* the config->find_vqs() implementation */
133int 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);
137const 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 */
144int vp_set_vq_affinity(struct virtqueue *vq, int cpu);
145
146const struct cpumask *vp_get_vq_affinity(struct virtio_device *vdev, int index);
147
148#if IS_ENABLED(CONFIG_VIRTIO_PCI_LEGACY)
149int virtio_pci_legacy_probe(struct virtio_pci_device *);
150void virtio_pci_legacy_remove(struct virtio_pci_device *);
151#else
152static inline int virtio_pci_legacy_probe(struct virtio_pci_device *vp_dev)
153{
154	return -ENODEV;
155}
156static inline void virtio_pci_legacy_remove(struct virtio_pci_device *vp_dev)
157{
158}
159#endif
160int virtio_pci_modern_probe(struct virtio_pci_device *);
161void virtio_pci_modern_remove(struct virtio_pci_device *);
162
163#endif