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
 31struct 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 */
 43struct 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. */
112enum {
113	VP_MSIX_CONFIG_VECTOR = 0,
114	VP_MSIX_VQ_VECTOR = 1,
115};
116
117/* Convert a generic virtio device to our structure */
118static 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 */
124void vp_synchronize_vectors(struct virtio_device *vdev);
125/* the notify function used when creating a virt queue */
126bool vp_notify(struct virtqueue *vq);
127/* the config->del_vqs() implementation */
128void vp_del_vqs(struct virtio_device *vdev);
129/* the config->find_vqs() implementation */
130int 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);
134const 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 */
141int vp_set_vq_affinity(struct virtqueue *vq, const struct cpumask *cpu_mask);
142
143const struct cpumask *vp_get_vq_affinity(struct virtio_device *vdev, int index);
144
145#if IS_ENABLED(CONFIG_VIRTIO_PCI_LEGACY)
146int virtio_pci_legacy_probe(struct virtio_pci_device *);
147void virtio_pci_legacy_remove(struct virtio_pci_device *);
148#else
149static inline int virtio_pci_legacy_probe(struct virtio_pci_device *vp_dev)
150{
151	return -ENODEV;
152}
153static inline void virtio_pci_legacy_remove(struct virtio_pci_device *vp_dev)
154{
155}
156#endif
157int virtio_pci_modern_probe(struct virtio_pci_device *);
158void virtio_pci_modern_remove(struct virtio_pci_device *);
159
160#endif