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 31 struct 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 */ 43 struct 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. */ 112 enum { 113 VP_MSIX_CONFIG_VECTOR = 0, 114 VP_MSIX_VQ_VECTOR = 1, 115 }; 116 117 /* Convert a generic virtio device to our structure */ 118 static 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 */ 124 void vp_synchronize_vectors(struct virtio_device *vdev); 125 /* the notify function used when creating a virt queue */ 126 bool vp_notify(struct virtqueue *vq); 127 /* the config->del_vqs() implementation */ 128 void vp_del_vqs(struct virtio_device *vdev); 129 /* the config->find_vqs() implementation */ 130 int 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); 134 const 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 */ 141 int vp_set_vq_affinity(struct virtqueue *vq, const struct cpumask *cpu_mask); 142 143 const struct cpumask *vp_get_vq_affinity(struct virtio_device *vdev, int index); 144 145 #if IS_ENABLED(CONFIG_VIRTIO_PCI_LEGACY) 146 int virtio_pci_legacy_probe(struct virtio_pci_device *); 147 void virtio_pci_legacy_remove(struct virtio_pci_device *); 148 #else 149 static inline int virtio_pci_legacy_probe(struct virtio_pci_device *vp_dev) 150 { 151 return -ENODEV; 152 } 153 static inline void virtio_pci_legacy_remove(struct virtio_pci_device *vp_dev) 154 { 155 } 156 #endif 157 int virtio_pci_modern_probe(struct virtio_pci_device *); 158 void virtio_pci_modern_remove(struct virtio_pci_device *); 159 160 #endif 161