1 #ifndef _VIRTIO_RING_H_ 2 # define _VIRTIO_RING_H_ 3 #define PAGE_SHIFT (12) 4 #define PAGE_SIZE (1<<PAGE_SHIFT) 5 #define PAGE_MASK (PAGE_SIZE-1) 6 7 /* Status byte for guest to report progress, and synchronize features. */ 8 /* We have seen device and processed generic fields (VIRTIO_CONFIG_F_VIRTIO) */ 9 #define VIRTIO_CONFIG_S_ACKNOWLEDGE 1 10 /* We have found a driver for the device. */ 11 #define VIRTIO_CONFIG_S_DRIVER 2 12 /* Driver has used its parts of the config, and is happy */ 13 #define VIRTIO_CONFIG_S_DRIVER_OK 4 14 /* We've given up on this device. */ 15 #define VIRTIO_CONFIG_S_FAILED 0x80 16 17 #define MAX_QUEUE_NUM (512) 18 19 #define VRING_DESC_F_NEXT 1 20 #define VRING_DESC_F_WRITE 2 21 22 #define VRING_AVAIL_F_NO_INTERRUPT 1 23 24 #define VRING_USED_F_NO_NOTIFY 1 25 26 struct vring_desc 27 { 28 u64 addr; 29 u32 len; 30 u16 flags; 31 u16 next; 32 }; 33 34 struct vring_avail 35 { 36 u16 flags; 37 u16 idx; 38 u16 ring[0]; 39 }; 40 41 struct vring_used_elem 42 { 43 u32 id; 44 u32 len; 45 }; 46 47 struct vring_used 48 { 49 u16 flags; 50 u16 idx; 51 struct vring_used_elem ring[]; 52 }; 53 54 struct vring { 55 unsigned int num; 56 struct vring_desc *desc; 57 struct vring_avail *avail; 58 struct vring_used *used; 59 }; 60 61 #define vring_size(num) \ 62 (((((sizeof(struct vring_desc) * num) + \ 63 (sizeof(struct vring_avail) + sizeof(u16) * num)) \ 64 + PAGE_MASK) & ~PAGE_MASK) + \ 65 (sizeof(struct vring_used) + sizeof(struct vring_used_elem) * num)) 66 67 typedef unsigned char virtio_queue_t[PAGE_MASK + vring_size(MAX_QUEUE_NUM)]; 68 69 struct vring_virtqueue { 70 virtio_queue_t queue; 71 struct vring vring; 72 u16 free_head; 73 u16 last_used_idx; 74 u16 vdata[MAX_QUEUE_NUM]; 75 /* PCI */ 76 int queue_index; 77 }; 78 79 struct vring_list { 80 char *addr; 81 unsigned int length; 82 }; 83 84 static inline void vring_init(struct vring *vr, 85 unsigned int num, unsigned char *queue) 86 { 87 unsigned int i; 88 unsigned long pa; 89 90 vr->num = num; 91 92 /* physical address of desc must be page aligned */ 93 94 pa = virt_to_phys(queue); 95 pa = (pa + PAGE_MASK) & ~PAGE_MASK; 96 vr->desc = phys_to_virt(pa); 97 98 vr->avail = (struct vring_avail *)&vr->desc[num]; 99 100 /* physical address of used must be page aligned */ 101 102 pa = virt_to_phys(&vr->avail->ring[num]); 103 pa = (pa + PAGE_MASK) & ~PAGE_MASK; 104 vr->used = phys_to_virt(pa); 105 106 for (i = 0; i < num - 1; i++) 107 vr->desc[i].next = i + 1; 108 vr->desc[i].next = 0; 109 } 110 111 static inline void vring_enable_cb(struct vring_virtqueue *vq) 112 { 113 vq->vring.avail->flags &= ~VRING_AVAIL_F_NO_INTERRUPT; 114 } 115 116 static inline void vring_disable_cb(struct vring_virtqueue *vq) 117 { 118 vq->vring.avail->flags |= VRING_AVAIL_F_NO_INTERRUPT; 119 } 120 121 122 /* 123 * vring_more_used 124 * 125 * is there some used buffers ? 126 * 127 */ 128 129 static inline int vring_more_used(struct vring_virtqueue *vq) 130 { 131 wmb(); 132 return vq->last_used_idx != vq->vring.used->idx; 133 } 134 135 void vring_detach(struct vring_virtqueue *vq, unsigned int head); 136 int vring_get_buf(struct vring_virtqueue *vq, unsigned int *len); 137 void vring_add_buf(struct vring_virtqueue *vq, struct vring_list list[], 138 unsigned int out, unsigned int in, 139 int index, int num_added); 140 void vring_kick(unsigned int ioaddr, struct vring_virtqueue *vq, int num_added); 141 142 #endif /* _VIRTIO_RING_H_ */ 143
