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 34 struct virtio_pci_vq_info { 35 /* the actual virtqueue */ 36 struct virtqueue *vq; 37 38 /* the number of entries in the queue */ 39 int num; 40 41 /* the virtual address of the ring queue */ 42 void *queue; 43 44 /* the list node for the virtqueues list */ 45 struct list_head node; 46 47 /* MSI-X vector (or none) */ 48 unsigned msix_vector; 49 }; 50 51 /* Our device structure */ 52 struct virtio_pci_device { 53 struct virtio_device vdev; 54 struct pci_dev *pci_dev; 55 56 /* In legacy mode, these two point to within ->legacy. */ 57 /* Where to read and clear interrupt */ 58 u8 __iomem *isr; 59 60 /* Modern only fields */ 61 /* The IO mapping for the PCI config space (non-legacy mode) */ 62 struct virtio_pci_common_cfg __iomem *common; 63 /* Device-specific data (non-legacy mode) */ 64 void __iomem *device; 65 /* Base of vq notifications (non-legacy mode). */ 66 void __iomem *notify_base; 67 68 /* So we can sanity-check accesses. */ 69 size_t notify_len; 70 size_t device_len; 71 72 /* Capability for when we need to map notifications per-vq. */ 73 int notify_map_cap; 74 75 /* Multiply queue_notify_off by this value. (non-legacy mode). */ 76 u32 notify_offset_multiplier; 77 78 /* Legacy only field */ 79 /* the IO mapping for the PCI config space */ 80 void __iomem *ioaddr; 81 82 /* a list of queues so we can dispatch IRQs */ 83 spinlock_t lock; 84 struct list_head virtqueues; 85 86 /* array of all queues for house-keeping */ 87 struct virtio_pci_vq_info **vqs; 88 89 /* MSI-X support */ 90 int msix_enabled; 91 int intx_enabled; 92 struct msix_entry *msix_entries; 93 cpumask_var_t *msix_affinity_masks; 94 /* Name strings for interrupts. This size should be enough, 95 * and I'm too lazy to allocate each name separately. */ 96 char (*msix_names)[256]; 97 /* Number of available vectors */ 98 unsigned msix_vectors; 99 /* Vectors allocated, excluding per-vq vectors if any */ 100 unsigned msix_used_vectors; 101 102 /* Whether we have vector per vq */ 103 bool per_vq_vectors; 104 105 struct virtqueue *(*setup_vq)(struct virtio_pci_device *vp_dev, 106 struct virtio_pci_vq_info *info, 107 unsigned idx, 108 void (*callback)(struct virtqueue *vq), 109 const char *name, 110 u16 msix_vec); 111 void (*del_vq)(struct virtio_pci_vq_info *info); 112 113 u16 (*config_vector)(struct virtio_pci_device *vp_dev, u16 vector); 114 }; 115 116 /* Constants for MSI-X */ 117 /* Use first vector for configuration changes, second and the rest for 118 * virtqueues Thus, we need at least 2 vectors for MSI. */ 119 enum { 120 VP_MSIX_CONFIG_VECTOR = 0, 121 VP_MSIX_VQ_VECTOR = 1, 122 }; 123 124 /* Convert a generic virtio device to our structure */ 125 static struct virtio_pci_device *to_vp_device(struct virtio_device *vdev) 126 { 127 return container_of(vdev, struct virtio_pci_device, vdev); 128 } 129 130 /* wait for pending irq handlers */ 131 void vp_synchronize_vectors(struct virtio_device *vdev); 132 /* the notify function used when creating a virt queue */ 133 bool vp_notify(struct virtqueue *vq); 134 /* the config->del_vqs() implementation */ 135 void vp_del_vqs(struct virtio_device *vdev); 136 /* the config->find_vqs() implementation */ 137 int vp_find_vqs(struct virtio_device *vdev, unsigned nvqs, 138 struct virtqueue *vqs[], 139 vq_callback_t *callbacks[], 140 const char *names[]); 141 const char *vp_bus_name(struct virtio_device *vdev); 142 143 /* Setup the affinity for a virtqueue: 144 * - force the affinity for per vq vector 145 * - OR over all affinities for shared MSI 146 * - ignore the affinity request if we're using INTX 147 */ 148 int vp_set_vq_affinity(struct virtqueue *vq, int cpu); 149 150 #if IS_ENABLED(CONFIG_VIRTIO_PCI_LEGACY) 151 int virtio_pci_legacy_probe(struct virtio_pci_device *); 152 void virtio_pci_legacy_remove(struct virtio_pci_device *); 153 #else 154 static inline int virtio_pci_legacy_probe(struct virtio_pci_device *vp_dev) 155 { 156 return -ENODEV; 157 } 158 static inline void virtio_pci_legacy_remove(struct virtio_pci_device *vp_dev) 159 { 160 } 161 #endif 162 int virtio_pci_modern_probe(struct virtio_pci_device *); 163 void virtio_pci_modern_remove(struct virtio_pci_device *); 164 165 #endif 166