static int map_data_for_request(struct vscsifrnt_info *info,
struct scsi_cmnd *sc,
struct vscsiif_request *ring_req,
struct vscsifrnt_shadow *shadow)
{
grant_ref_t gref_head;
struct page *page;
int err, ref, ref_cnt = 0;
int grant_ro = (sc->sc_data_direction == DMA_TO_DEVICE);
unsigned int i, off, len, bytes;
unsigned int data_len = scsi_bufflen(sc);
unsigned int data_grants = 0, seg_grants = 0;
struct scatterlist *sg;
unsigned long mfn;
struct scsiif_request_segment *seg;
ring_req->nr_segments = 0;
if (sc->sc_data_direction == DMA_NONE || !data_len)
return 0;
scsi_for_each_sg(sc, sg, scsi_sg_count(sc), i)
data_grants += PFN_UP(sg->offset + sg->length);
if (data_grants > VSCSIIF_SG_TABLESIZE) {
if (data_grants > info->host->sg_tablesize) {
shost_printk(KERN_ERR, info->host, KBUILD_MODNAME
"Unable to map request_buffer for command!\n");
return -E2BIG;
}
seg_grants = vscsiif_grants_sg(data_grants);
shadow->sg = kcalloc(data_grants,
sizeof(struct scsiif_request_segment), GFP_ATOMIC);
if (!shadow->sg)
return -ENOMEM;
}
seg = shadow->sg ? : ring_req->seg;
err = gnttab_alloc_grant_references(seg_grants + data_grants,
&gref_head);
if (err) {
kfree(shadow->sg);
shost_printk(KERN_ERR, info->host, KBUILD_MODNAME
"gnttab_alloc_grant_references() error\n");
return -ENOMEM;
}
if (seg_grants) {
page = virt_to_page(seg);
off = (unsigned long)seg & ~PAGE_MASK;
len = sizeof(struct scsiif_request_segment) * data_grants;
while (len > 0) {
bytes = min_t(unsigned int, len, PAGE_SIZE - off);
ref = gnttab_claim_grant_reference(&gref_head);
BUG_ON(ref == -ENOSPC);
mfn = pfn_to_mfn(page_to_pfn(page));
gnttab_grant_foreign_access_ref(ref,
info->dev->otherend_id, mfn, 1);
shadow->gref[ref_cnt] = ref;
ring_req->seg[ref_cnt].gref = ref;
ring_req->seg[ref_cnt].offset = (uint16_t)off;
ring_req->seg[ref_cnt].length = (uint16_t)bytes;
page++;
len -= bytes;
off = 0;
ref_cnt++;
}
BUG_ON(seg_grants < ref_cnt);
seg_grants = ref_cnt;
}
scsi_for_each_sg(sc, sg, scsi_sg_count(sc), i) {
page = sg_page(sg);
off = sg->offset;
len = sg->length;
while (len > 0 && data_len > 0) {
/*
* sg sends a scatterlist that is larger than
* the data_len it wants transferred for certain
* IO sizes.
*/
bytes = min_t(unsigned int, len, PAGE_SIZE - off);
bytes = min(bytes, data_len);
ref = gnttab_claim_grant_reference(&gref_head);
BUG_ON(ref == -ENOSPC);
mfn = pfn_to_mfn(page_to_pfn(page));
gnttab_grant_foreign_access_ref(ref,
info->dev->otherend_id, mfn, grant_ro);
shadow->gref[ref_cnt] = ref;
seg->gref = ref;
seg->offset = (uint16_t)off;
seg->length = (uint16_t)bytes;
page++;
seg++;
len -= bytes;
data_len -= bytes;
off = 0;
ref_cnt++;
}
}
/*
* blkif_queue_request
*
* request block io
*
* id: for guest use only.
* operation: BLKIF_OP_{READ,WRITE,PROBE}
* buffer: buffer to read/write into. this should be a
* virtual address in the guest os.
*/
int ixp_queue_request(struct app_request *app_req, void *metadata)
{
struct ixpfront_info *info = (struct ixpfront_info *) metadata;
unsigned long buffer_mfn;
struct ixp_request *ring_req;
char *req_page = 0, *curr_pos;
unsigned long id;
int ref, err;
grant_ref_t gref_head;
if (unlikely(info->connected != IXP_STATE_CONNECTED))
return 1;
if (RING_FULL(&info->ring)) {
printk(KERN_ERR "%s:Ring full - returning backpressure\n", __FUNCTION__);
return 1;
}
if (gnttab_alloc_grant_references(
IXPIF_MAX_SEGMENTS_PER_REQUEST, &gref_head) < 0) {
/*gnttab_request_free_callback(
&info->callback,
ixp_restart_queue_callback,
info,
IXP_MAX_SEGMENTS_PER_REQUEST);*/
return 1;
}
/* Fill out a communications ring structure. */
ring_req = RING_GET_REQUEST(&info->ring, info->ring.req_prod_pvt);
id = get_id_from_freelist(info);
ring_req->id = id;
ring_req->handle = info->handle;
ring_req->operation = IXP_OP_3DES_ENCRYPT;
ring_req->nr_segments = 1;
BUG_ON(ring_req->nr_segments > IXPIF_MAX_SEGMENTS_PER_REQUEST);
req_page = (char *)__get_free_page(GFP_NOIO | __GFP_HIGH);
if(req_page == 0) {
printk(KERN_ERR "ixp_queue_request:Error allocating memory");
return 1;
}
((struct des_request *)req_page)->key_size = app_req->key_size;
((struct des_request *)req_page)->iv_size = app_req->iv_size;
((struct des_request *)req_page)->msg_size = app_req->msg_size;
curr_pos = req_page + sizeof(struct des_request);
memcpy(curr_pos, app_req->key, app_req->key_size);
curr_pos += app_req->key_size;
memcpy(curr_pos, app_req->iv, app_req->iv_size);
curr_pos += app_req->iv_size;
memcpy(curr_pos, app_req->msg, app_req->msg_size);
curr_pos += app_req->msg_size;
buffer_mfn = virt_to_mfn(req_page);
/* install a grant reference. */
ref = gnttab_claim_grant_reference(&gref_head);
BUG_ON(ref == -ENOSPC);
gnttab_grant_foreign_access_ref(
ref,
info->xbdev->otherend_id,
buffer_mfn,
0);
info->shadow[id].r_params.presp = app_req->presp;
info->shadow[id].r_params.callbk_tag = app_req->callbk_tag;
info->shadow[id].frame[0] = mfn_to_pfn(buffer_mfn);
info->shadow[id].req_page = req_page;
ring_req->seg[0] =
(struct ixp_request_segment) {
.gref = ref
};
info->ring.req_prod_pvt++;
/* Keep a private copy so we can reissue requests when recovering. */
info->shadow[id].req = *ring_req;
flush_requests(info);
//gnttab_free_grant_references(gref_head);
return 0;
}
