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/* virtio-pci.c - virtio ring management
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* (c) Copyright 2008 Bull S.A.S.
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* Author: Laurent Vivier <Laurent.Vivier@bull.net>
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* some parts from Linux Virtio Ring
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* Copyright Rusty Russell IBM Corporation 2007
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* Adopted for Seabios: Gleb Natapov <gleb@redhat.com>
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* This work is licensed under the terms of the GNU LGPLv3
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* See the COPYING file in the top-level directory.
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#include "virtio-ring.h"
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#include "virtio-pci.h"
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#include "biosvar.h" // GET_GLOBAL
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#include "util.h" // dprintf
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dprintf(1, "BUG: failure at %s:%d/%s()!\n", \
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__FILE__, __LINE__, __func__); \
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#define BUG_ON(condition) do { if (condition) BUG(); } while (0)
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* is there some used buffers ?
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int vring_more_used(struct vring_virtqueue *vq)
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struct vring_used *used = GET_FLATPTR(vq->vring.used);
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return GET_FLATPTR(vq->last_used_idx) != GET_FLATPTR(used->idx);
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* put at the begin of the free list the current desc[head]
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void vring_detach(struct vring_virtqueue *vq, unsigned int head)
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struct vring *vr = &vq->vring;
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struct vring_desc *desc = GET_FLATPTR(vr->desc);
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/* find end of given descriptor */
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while (GET_FLATPTR(desc[i].flags) & VRING_DESC_F_NEXT)
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i = GET_FLATPTR(desc[i].next);
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/* link it with free list and point to it */
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SET_FLATPTR(desc[i].next, GET_FLATPTR(vq->free_head));
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SET_FLATPTR(vq->free_head, head);
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* get a buffer from the used list
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int vring_get_buf(struct vring_virtqueue *vq, unsigned int *len)
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struct vring *vr = &vq->vring;
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struct vring_used_elem *elem;
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struct vring_used *used = GET_FLATPTR(vq->vring.used);
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// BUG_ON(!vring_more_used(vq));
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elem = &used->ring[GET_FLATPTR(vq->last_used_idx) % GET_FLATPTR(vr->num)];
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id = GET_FLATPTR(elem->id);
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*len = GET_FLATPTR(elem->len);
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ret = GET_FLATPTR(vq->vdata[id]);
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SET_FLATPTR(vq->last_used_idx, GET_FLATPTR(vq->last_used_idx) + 1);
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void vring_add_buf(struct vring_virtqueue *vq,
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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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struct vring *vr = &vq->vring;
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int i, av, head, prev;
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struct vring_desc *desc = GET_FLATPTR(vr->desc);
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struct vring_avail *avail = GET_FLATPTR(vr->avail);
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BUG_ON(out + in == 0);
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head = GET_FLATPTR(vq->free_head);
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for (i = head; out; i = GET_FLATPTR(desc[i].next), out--) {
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SET_FLATPTR(desc[i].flags, VRING_DESC_F_NEXT);
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SET_FLATPTR(desc[i].addr, (u64)virt_to_phys(list->addr));
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SET_FLATPTR(desc[i].len, list->length);
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for ( ; in; i = GET_FLATPTR(desc[i].next), in--) {
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SET_FLATPTR(desc[i].flags, VRING_DESC_F_NEXT|VRING_DESC_F_WRITE);
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SET_FLATPTR(desc[i].addr, (u64)virt_to_phys(list->addr));
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SET_FLATPTR(desc[i].len, list->length);
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SET_FLATPTR(desc[prev].flags,
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GET_FLATPTR(desc[prev].flags) & ~VRING_DESC_F_NEXT);
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SET_FLATPTR(vq->free_head, i);
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SET_FLATPTR(vq->vdata[head], index);
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av = (GET_FLATPTR(avail->idx) + num_added) % GET_FLATPTR(vr->num);
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SET_FLATPTR(avail->ring[av], head);
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void vring_kick(unsigned int ioaddr, struct vring_virtqueue *vq, int num_added)
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struct vring *vr = &vq->vring;
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struct vring_avail *avail = GET_FLATPTR(vr->avail);
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struct vring_used *used = GET_FLATPTR(vq->vring.used);
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SET_FLATPTR(avail->idx, GET_FLATPTR(avail->idx) + num_added);
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if (!(GET_FLATPTR(used->flags) & VRING_USED_F_NO_NOTIFY))
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vp_notify(ioaddr, GET_FLATPTR(vq->queue_index));