diff options
author | 2015-08-28 09:58:54 +0800 | |
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committer | 2015-09-01 12:44:00 +0800 | |
commit | e44e3482bdb4d0ebde2d8b41830ac2cdb07948fb (patch) | |
tree | 66b09f592c55df2878107a468a91d21506104d3f /qemu/roms/seabios/src/hw/virtio-ring.c | |
parent | 9ca8dbcc65cfc63d6f5ef3312a33184e1d726e00 (diff) |
Add qemu 2.4.0
Change-Id: Ic99cbad4b61f8b127b7dc74d04576c0bcbaaf4f5
Signed-off-by: Yang Zhang <yang.z.zhang@intel.com>
Diffstat (limited to 'qemu/roms/seabios/src/hw/virtio-ring.c')
-rw-r--r-- | qemu/roms/seabios/src/hw/virtio-ring.c | 149 |
1 files changed, 149 insertions, 0 deletions
diff --git a/qemu/roms/seabios/src/hw/virtio-ring.c b/qemu/roms/seabios/src/hw/virtio-ring.c new file mode 100644 index 000000000..97e0b3487 --- /dev/null +++ b/qemu/roms/seabios/src/hw/virtio-ring.c @@ -0,0 +1,149 @@ +/* virtio-pci.c - virtio ring management + * + * (c) Copyright 2008 Bull S.A.S. + * + * Author: Laurent Vivier <Laurent.Vivier@bull.net> + * + * some parts from Linux Virtio Ring + * + * Copyright Rusty Russell IBM Corporation 2007 + * + * Adopted for Seabios: Gleb Natapov <gleb@redhat.com> + * + * This work is licensed under the terms of the GNU LGPLv3 + * See the COPYING file in the top-level directory. + * + * + */ + +#include "biosvar.h" // GET_GLOBAL +#include "output.h" // panic +#include "virtio-ring.h" +#include "virtio-pci.h" + +#define BUG() do { \ + panic("BUG: failure at %d/%s()!\n", __LINE__, __func__); \ + } while (0) +#define BUG_ON(condition) do { if (condition) BUG(); } while (0) + +/* + * vring_more_used + * + * is there some used buffers ? + * + */ + +int vring_more_used(struct vring_virtqueue *vq) +{ + struct vring_used *used = GET_LOWFLAT(vq->vring.used); + int more = GET_LOWFLAT(vq->last_used_idx) != GET_LOWFLAT(used->idx); + /* Make sure ring reads are done after idx read above. */ + smp_rmb(); + return more; +} + +/* + * vring_free + * + * put at the begin of the free list the current desc[head] + */ + +void vring_detach(struct vring_virtqueue *vq, unsigned int head) +{ + struct vring *vr = &vq->vring; + struct vring_desc *desc = GET_LOWFLAT(vr->desc); + unsigned int i; + + /* find end of given descriptor */ + + i = head; + while (GET_LOWFLAT(desc[i].flags) & VRING_DESC_F_NEXT) + i = GET_LOWFLAT(desc[i].next); + + /* link it with free list and point to it */ + + SET_LOWFLAT(desc[i].next, GET_LOWFLAT(vq->free_head)); + SET_LOWFLAT(vq->free_head, head); +} + +/* + * vring_get_buf + * + * get a buffer from the used list + * + */ + +int vring_get_buf(struct vring_virtqueue *vq, unsigned int *len) +{ + struct vring *vr = &vq->vring; + struct vring_used_elem *elem; + struct vring_used *used = GET_LOWFLAT(vq->vring.used); + u32 id; + int ret; + +// BUG_ON(!vring_more_used(vq)); + + elem = &used->ring[GET_LOWFLAT(vq->last_used_idx) % GET_LOWFLAT(vr->num)]; + id = GET_LOWFLAT(elem->id); + if (len != NULL) + *len = GET_LOWFLAT(elem->len); + + ret = GET_LOWFLAT(vq->vdata[id]); + + vring_detach(vq, id); + + SET_LOWFLAT(vq->last_used_idx, GET_LOWFLAT(vq->last_used_idx) + 1); + + return ret; +} + +void vring_add_buf(struct vring_virtqueue *vq, + struct vring_list list[], + unsigned int out, unsigned int in, + int index, int num_added) +{ + struct vring *vr = &vq->vring; + int i, av, head, prev; + struct vring_desc *desc = GET_LOWFLAT(vr->desc); + struct vring_avail *avail = GET_LOWFLAT(vr->avail); + + BUG_ON(out + in == 0); + + prev = 0; + head = GET_LOWFLAT(vq->free_head); + for (i = head; out; i = GET_LOWFLAT(desc[i].next), out--) { + SET_LOWFLAT(desc[i].flags, VRING_DESC_F_NEXT); + SET_LOWFLAT(desc[i].addr, (u64)virt_to_phys(list->addr)); + SET_LOWFLAT(desc[i].len, list->length); + prev = i; + list++; + } + for ( ; in; i = GET_LOWFLAT(desc[i].next), in--) { + SET_LOWFLAT(desc[i].flags, VRING_DESC_F_NEXT|VRING_DESC_F_WRITE); + SET_LOWFLAT(desc[i].addr, (u64)virt_to_phys(list->addr)); + SET_LOWFLAT(desc[i].len, list->length); + prev = i; + list++; + } + SET_LOWFLAT(desc[prev].flags, + GET_LOWFLAT(desc[prev].flags) & ~VRING_DESC_F_NEXT); + + SET_LOWFLAT(vq->free_head, i); + + SET_LOWFLAT(vq->vdata[head], index); + + av = (GET_LOWFLAT(avail->idx) + num_added) % GET_LOWFLAT(vr->num); + SET_LOWFLAT(avail->ring[av], head); +} + +void vring_kick(unsigned int ioaddr, struct vring_virtqueue *vq, int num_added) +{ + struct vring *vr = &vq->vring; + struct vring_avail *avail = GET_LOWFLAT(vr->avail); + + /* Make sure idx update is done after ring write. */ + smp_wmb(); + SET_LOWFLAT(avail->idx, GET_LOWFLAT(avail->idx) + num_added); + + vp_notify(ioaddr, GET_LOWFLAT(vq->queue_index)); +} |