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#include "types.h" // u64
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#include "memmap.h" // PAGE_SIZE
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#define PAGE_MASK (PAGE_SIZE-1)
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#define virt_to_phys(v) (unsigned long)(v)
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#define phys_to_virt(p) (void*)(p)
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/* Compiler barrier is enough as an x86 CPU does not reorder reads or writes */
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#define smp_rmb() barrier()
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#define smp_wmb() barrier()
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/* Status byte for guest to report progress, and synchronize features. */
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/* We have seen device and processed generic fields (VIRTIO_CONFIG_F_VIRTIO) */
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#define VIRTIO_CONFIG_S_ACKNOWLEDGE 1
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/* We have found a driver for the device. */
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#define VIRTIO_CONFIG_S_DRIVER 2
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/* Driver has used its parts of the config, and is happy */
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#define VIRTIO_CONFIG_S_DRIVER_OK 4
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/* We've given up on this device. */
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#define VIRTIO_CONFIG_S_FAILED 0x80
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#define MAX_QUEUE_NUM (128)
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#define VRING_DESC_F_NEXT 1
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#define VRING_DESC_F_WRITE 2
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#define VRING_AVAIL_F_NO_INTERRUPT 1
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#define VRING_USED_F_NO_NOTIFY 1
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struct vring_used_elem
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struct vring_used_elem ring[];
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struct vring_desc *desc;
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struct vring_avail *avail;
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struct vring_used *used;
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#define vring_size(num) \
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(((((sizeof(struct vring_desc) * num) + \
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(sizeof(struct vring_avail) + sizeof(u16) * num)) \
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+ PAGE_MASK) & ~PAGE_MASK) + \
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(sizeof(struct vring_used) + sizeof(struct vring_used_elem) * num))
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typedef unsigned char virtio_queue_t[vring_size(MAX_QUEUE_NUM)];
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struct vring_virtqueue {
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u16 vdata[MAX_QUEUE_NUM];
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static inline void vring_init(struct vring *vr,
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unsigned int num, unsigned char *queue)
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/* physical address of desc must be page aligned */
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pa = virt_to_phys(queue);
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pa = (pa + PAGE_MASK) & ~PAGE_MASK;
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vr->desc = phys_to_virt(pa);
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vr->avail = (struct vring_avail *)&vr->desc[num];
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/* disable interrupts */
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vr->avail->flags |= VRING_AVAIL_F_NO_INTERRUPT;
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/* physical address of used must be page aligned */
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pa = virt_to_phys(&vr->avail->ring[num]);
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pa = (pa + PAGE_MASK) & ~PAGE_MASK;
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vr->used = phys_to_virt(pa);
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for (i = 0; i < num - 1; i++)
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vr->desc[i].next = i + 1;
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vr->desc[i].next = 0;
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int vring_more_used(struct vring_virtqueue *vq);
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void vring_detach(struct vring_virtqueue *vq, unsigned int head);
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int vring_get_buf(struct vring_virtqueue *vq, unsigned int *len);
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void vring_add_buf(struct vring_virtqueue *vq, struct vring_list list[],
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unsigned int out, unsigned int in,
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int index, int num_added);
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void vring_kick(unsigned int ioaddr, struct vring_virtqueue *vq, int num_added);
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#endif /* _VIRTIO_RING_H_ */