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 33 struct virtio_pci_vq_info { 34 /* the actual virtqueue */ 35 struct virtqueue *vq; 36 37 /* the list node for the virtqueues list */ 38 struct list_head node; 39 40 /* MSI-X vector (or none) */ 41 unsigned int msix_vector; 42 }; 43 44 /* Our device structure */ 45 struct virtio_pci_device { 46 struct virtio_device vdev; 47 struct pci_dev *pci_dev; 48 union { 49 struct virtio_pci_legacy_device ldev; 50 struct virtio_pci_modern_device mdev; 51 }; 52 bool is_legacy; 53 54 /* Where to read and clear interrupt */ 55 u8 __iomem *isr; 56 57 /* a list of queues so we can dispatch IRQs */ 58 spinlock_t lock; 59 struct list_head virtqueues; 60 61 /* array of all queues for house-keeping */ 62 struct virtio_pci_vq_info **vqs; 63 64 /* MSI-X support */ 65 int msix_enabled; 66 int intx_enabled; 67 cpumask_var_t *msix_affinity_masks; 68 /* Name strings for interrupts. This size should be enough, 69 * and I'm too lazy to allocate each name separately. */ 70 char (*msix_names)[256]; 71 /* Number of available vectors */ 72 unsigned int msix_vectors; 73 /* Vectors allocated, excluding per-vq vectors if any */ 74 unsigned int msix_used_vectors; 75 76 /* Whether we have vector per vq */ 77 bool per_vq_vectors; 78 79 struct virtqueue *(*setup_vq)(struct virtio_pci_device *vp_dev, 80 struct virtio_pci_vq_info *info, 81 unsigned int idx, 82 void (*callback)(struct virtqueue *vq), 83 const char *name, 84 bool ctx, 85 u16 msix_vec); 86 void (*del_vq)(struct virtio_pci_vq_info *info); 87 88 u16 (*config_vector)(struct virtio_pci_device *vp_dev, u16 vector); 89 }; 90 91 /* Constants for MSI-X */ 92 /* Use first vector for configuration changes, second and the rest for 93 * virtqueues Thus, we need at least 2 vectors for MSI. */ 94 enum { 95 VP_MSIX_CONFIG_VECTOR = 0, 96 VP_MSIX_VQ_VECTOR = 1, 97 }; 98 99 /* Convert a generic virtio device to our structure */ 100 static struct virtio_pci_device *to_vp_device(struct virtio_device *vdev) 101 { 102 return container_of(vdev, struct virtio_pci_device, vdev); 103 } 104 105 /* wait for pending irq handlers */ 106 void vp_synchronize_vectors(struct virtio_device *vdev); 107 /* the notify function used when creating a virt queue */ 108 bool vp_notify(struct virtqueue *vq); 109 /* the config->del_vqs() implementation */ 110 void vp_del_vqs(struct virtio_device *vdev); 111 /* the config->find_vqs() implementation */ 112 int vp_find_vqs(struct virtio_device *vdev, unsigned int nvqs, 113 struct virtqueue *vqs[], vq_callback_t *callbacks[], 114 const char * const names[], const bool *ctx, 115 struct irq_affinity *desc); 116 const char *vp_bus_name(struct virtio_device *vdev); 117 118 /* Setup the affinity for a virtqueue: 119 * - force the affinity for per vq vector 120 * - OR over all affinities for shared MSI 121 * - ignore the affinity request if we're using INTX 122 */ 123 int vp_set_vq_affinity(struct virtqueue *vq, const struct cpumask *cpu_mask); 124 125 const struct cpumask *vp_get_vq_affinity(struct virtio_device *vdev, int index); 126 127 #if IS_ENABLED(CONFIG_VIRTIO_PCI_LEGACY) 128 int virtio_pci_legacy_probe(struct virtio_pci_device *); 129 void virtio_pci_legacy_remove(struct virtio_pci_device *); 130 #else 131 static inline int virtio_pci_legacy_probe(struct virtio_pci_device *vp_dev) 132 { 133 return -ENODEV; 134 } 135 static inline void virtio_pci_legacy_remove(struct virtio_pci_device *vp_dev) 136 { 137 } 138 #endif 139 int virtio_pci_modern_probe(struct virtio_pci_device *); 140 void virtio_pci_modern_remove(struct virtio_pci_device *); 141 142 #endif 143