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_legacy.h>
 29#include <linux/virtio_pci_modern.h>
 30#include <linux/highmem.h>
 31#include <linux/spinlock.h>
 32#include <linux/mutex.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 int msix_vector;
 43};
 44
 45struct virtio_pci_admin_vq {
 46	/* Virtqueue info associated with this admin queue. */
 47	struct virtio_pci_vq_info info;
 48	/* serializing admin commands execution and virtqueue deletion */
 49	struct mutex cmd_lock;
 50	u64 supported_cmds;
 51	/* Name of the admin queue: avq.$vq_index. */
 52	char name[10];
 53	u16 vq_index;
 54};
 55
 56/* Our device structure */
 57struct virtio_pci_device {
 58	struct virtio_device vdev;
 59	struct pci_dev *pci_dev;
 60	union {
 61		struct virtio_pci_legacy_device ldev;
 62		struct virtio_pci_modern_device mdev;
 63	};
 64	bool is_legacy;
 65
 66	/* Where to read and clear interrupt */
 67	u8 __iomem *isr;
 68
 69	/* a list of queues so we can dispatch IRQs */
 70	spinlock_t lock;
 71	struct list_head virtqueues;
 72
 73	/* Array of all virtqueues reported in the
 74	 * PCI common config num_queues field
 75	 */
 76	struct virtio_pci_vq_info **vqs;
 77
 78	struct virtio_pci_admin_vq admin_vq;
 79
 80	/* MSI-X support */
 81	int msix_enabled;
 82	int intx_enabled;
 83	cpumask_var_t *msix_affinity_masks;
 84	/* Name strings for interrupts. This size should be enough,
 85	 * and I'm too lazy to allocate each name separately. */
 86	char (*msix_names)[256];
 87	/* Number of available vectors */
 88	unsigned int msix_vectors;
 89	/* Vectors allocated, excluding per-vq vectors if any */
 90	unsigned int msix_used_vectors;
 91
 92	/* Whether we have vector per vq */
 93	bool per_vq_vectors;
 94
 95	struct virtqueue *(*setup_vq)(struct virtio_pci_device *vp_dev,
 96				      struct virtio_pci_vq_info *info,
 97				      unsigned int idx,
 98				      void (*callback)(struct virtqueue *vq),
 99				      const char *name,
100				      bool ctx,
101				      u16 msix_vec);
102	void (*del_vq)(struct virtio_pci_vq_info *info);
103
104	u16 (*config_vector)(struct virtio_pci_device *vp_dev, u16 vector);
105	bool (*is_avq)(struct virtio_device *vdev, unsigned int index);
106};
107
108/* Constants for MSI-X */
109/* Use first vector for configuration changes, second and the rest for
110 * virtqueues Thus, we need at least 2 vectors for MSI. */
111enum {
112	VP_MSIX_CONFIG_VECTOR = 0,
113	VP_MSIX_VQ_VECTOR = 1,
114};
115
116/* Convert a generic virtio device to our structure */
117static struct virtio_pci_device *to_vp_device(struct virtio_device *vdev)
118{
119	return container_of(vdev, struct virtio_pci_device, vdev);
120}
121
122/* wait for pending irq handlers */
123void vp_synchronize_vectors(struct virtio_device *vdev);
124/* the notify function used when creating a virt queue */
125bool vp_notify(struct virtqueue *vq);
126/* the config->del_vqs() implementation */
127void vp_del_vqs(struct virtio_device *vdev);
128/* the config->find_vqs() implementation */
129int vp_find_vqs(struct virtio_device *vdev, unsigned int nvqs,
130		struct virtqueue *vqs[], vq_callback_t *callbacks[],
131		const char * const names[], const bool *ctx,
132		struct irq_affinity *desc);
133const char *vp_bus_name(struct virtio_device *vdev);
134
135/* Setup the affinity for a virtqueue:
136 * - force the affinity for per vq vector
137 * - OR over all affinities for shared MSI
138 * - ignore the affinity request if we're using INTX
139 */
140int vp_set_vq_affinity(struct virtqueue *vq, const struct cpumask *cpu_mask);
141
142const struct cpumask *vp_get_vq_affinity(struct virtio_device *vdev, int index);
143
144#if IS_ENABLED(CONFIG_VIRTIO_PCI_LEGACY)
145int virtio_pci_legacy_probe(struct virtio_pci_device *);
146void virtio_pci_legacy_remove(struct virtio_pci_device *);
147#else
148static inline int virtio_pci_legacy_probe(struct virtio_pci_device *vp_dev)
149{
150	return -ENODEV;
151}
152static inline void virtio_pci_legacy_remove(struct virtio_pci_device *vp_dev)
153{
154}
155#endif
156int virtio_pci_modern_probe(struct virtio_pci_device *);
157void virtio_pci_modern_remove(struct virtio_pci_device *);
158
159struct virtio_device *virtio_pci_vf_get_pf_dev(struct pci_dev *pdev);
160
161#define VIRTIO_LEGACY_ADMIN_CMD_BITMAP \
162	(BIT_ULL(VIRTIO_ADMIN_CMD_LEGACY_COMMON_CFG_WRITE) | \
163	 BIT_ULL(VIRTIO_ADMIN_CMD_LEGACY_COMMON_CFG_READ) | \
164	 BIT_ULL(VIRTIO_ADMIN_CMD_LEGACY_DEV_CFG_WRITE) | \
165	 BIT_ULL(VIRTIO_ADMIN_CMD_LEGACY_DEV_CFG_READ) | \
166	 BIT_ULL(VIRTIO_ADMIN_CMD_LEGACY_NOTIFY_INFO))
167
168/* Unlike modern drivers which support hardware virtio devices, legacy drivers
169 * assume software-based devices: e.g. they don't use proper memory barriers
170 * on ARM, use big endian on PPC, etc. X86 drivers are mostly ok though, more
171 * or less by chance. For now, only support legacy IO on X86.
172 */
173#ifdef CONFIG_VIRTIO_PCI_ADMIN_LEGACY
174#define VIRTIO_ADMIN_CMD_BITMAP VIRTIO_LEGACY_ADMIN_CMD_BITMAP
175#else
176#define VIRTIO_ADMIN_CMD_BITMAP 0
177#endif
178
179int vp_modern_admin_cmd_exec(struct virtio_device *vdev,
180			     struct virtio_admin_cmd *cmd);
181
182#endif