/*
* Deliver read data back to initiator.
* XXX TBD handle resource problems later.
*/
int ft_queue_data_in(struct se_cmd *se_cmd)
{
struct ft_cmd *cmd = container_of(se_cmd, struct ft_cmd, se_cmd);
struct fc_frame *fp = NULL;
struct fc_exch *ep;
struct fc_lport *lport;
struct scatterlist *sg = NULL;
size_t remaining;
u32 f_ctl = FC_FC_EX_CTX | FC_FC_REL_OFF;
u32 mem_off = 0;
u32 fh_off = 0;
u32 frame_off = 0;
size_t frame_len = 0;
size_t mem_len = 0;
size_t tlen;
size_t off_in_page;
struct page *page = NULL;
int use_sg;
int error;
void *page_addr;
void *from;
void *to = NULL;
if (cmd->aborted)
return 0;
if (se_cmd->scsi_status == SAM_STAT_TASK_SET_FULL)
goto queue_status;
ep = fc_seq_exch(cmd->seq);
lport = ep->lp;
cmd->seq = lport->tt.seq_start_next(cmd->seq);
remaining = se_cmd->data_length;
/*
* Setup to use first mem list entry, unless no data.
*/
BUG_ON(remaining && !se_cmd->t_data_sg);
if (remaining) {
sg = se_cmd->t_data_sg;
mem_len = sg->length;
mem_off = sg->offset;
page = sg_page(sg);
}
/* no scatter/gather in skb for odd word length due to fc_seq_send() */
use_sg = !(remaining % 4);
while (remaining) {
struct fc_seq *seq = cmd->seq;
if (!seq) {
pr_debug("%s: Command aborted, xid 0x%x\n",
__func__, ep->xid);
break;
}
if (!mem_len) {
sg = sg_next(sg);
mem_len = min((size_t)sg->length, remaining);
mem_off = sg->offset;
page = sg_page(sg);
}
if (!frame_len) {
/*
* If lport's has capability of Large Send Offload LSO)
* , then allow 'frame_len' to be as big as 'lso_max'
* if indicated transfer length is >= lport->lso_max
*/
frame_len = (lport->seq_offload) ? lport->lso_max :
cmd->sess->max_frame;
frame_len = min(frame_len, remaining);
fp = fc_frame_alloc(lport, use_sg ? 0 : frame_len);
if (!fp)
return -ENOMEM;
to = fc_frame_payload_get(fp, 0);
fh_off = frame_off;
frame_off += frame_len;
/*
* Setup the frame's max payload which is used by base
* driver to indicate HW about max frame size, so that
* HW can do fragmentation appropriately based on
* "gso_max_size" of underline netdev.
*/
fr_max_payload(fp) = cmd->sess->max_frame;
}
tlen = min(mem_len, frame_len);
if (use_sg) {
off_in_page = mem_off;
BUG_ON(!page);
get_page(page);
skb_fill_page_desc(fp_skb(fp),
skb_shinfo(fp_skb(fp))->nr_frags,
page, off_in_page, tlen);
fr_len(fp) += tlen;
fp_skb(fp)->data_len += tlen;
fp_skb(fp)->truesize +=
PAGE_SIZE << compound_order(page);
} else {
BUG_ON(!page);
from = kmap_atomic(page + (mem_off >> PAGE_SHIFT));
page_addr = from;
from += mem_off & ~PAGE_MASK;
tlen = min(tlen, (size_t)(PAGE_SIZE -
(mem_off & ~PAGE_MASK)));
memcpy(to, from, tlen);
kunmap_atomic(page_addr);
to += tlen;
}
mem_off += tlen;
mem_len -= tlen;
frame_len -= tlen;
remaining -= tlen;
if (frame_len &&
(skb_shinfo(fp_skb(fp))->nr_frags < FC_FRAME_SG_LEN))
continue;
if (!remaining)
f_ctl |= FC_FC_END_SEQ;
fc_fill_fc_hdr(fp, FC_RCTL_DD_SOL_DATA, ep->did, ep->sid,
FC_TYPE_FCP, f_ctl, fh_off);
error = lport->tt.seq_send(lport, seq, fp);
if (error) {
pr_info_ratelimited("%s: Failed to send frame %p, "
"xid <0x%x>, remaining %zu, "
"lso_max <0x%x>\n",
__func__, fp, ep->xid,
remaining, lport->lso_max);
/*
* Go ahead and set TASK_SET_FULL status ignoring the
* rest of the DataIN, and immediately attempt to
* send the response via ft_queue_status() in order
* to notify the initiator that it should reduce it's
* per LUN queue_depth.
*/
se_cmd->scsi_status = SAM_STAT_TASK_SET_FULL;
break;
}
}
queue_status:
return ft_queue_status(se_cmd);
}
/*
* Send new command to target.
*/
static void ft_send_cmd(struct ft_cmd *cmd)
{
struct fc_frame_header *fh = fc_frame_header_get(cmd->req_frame);
struct se_cmd *se_cmd;
struct fcp_cmnd *fcp;
int data_dir;
u32 data_len;
int task_attr;
int ret;
fcp = fc_frame_payload_get(cmd->req_frame, sizeof(*fcp));
if (!fcp)
goto err;
if (fcp->fc_flags & FCP_CFL_LEN_MASK)
goto err; /* not handling longer CDBs yet */
if (fcp->fc_tm_flags) {
task_attr = FCP_PTA_SIMPLE;
data_dir = DMA_NONE;
data_len = 0;
} else {
switch (fcp->fc_flags & (FCP_CFL_RDDATA | FCP_CFL_WRDATA)) {
case 0:
data_dir = DMA_NONE;
break;
case FCP_CFL_RDDATA:
data_dir = DMA_FROM_DEVICE;
break;
case FCP_CFL_WRDATA:
data_dir = DMA_TO_DEVICE;
break;
case FCP_CFL_WRDATA | FCP_CFL_RDDATA:
goto err; /* TBD not supported by tcm_fc yet */
}
/*
* Locate the SAM Task Attr from fc_pri_ta
*/
switch (fcp->fc_pri_ta & FCP_PTA_MASK) {
case FCP_PTA_HEADQ:
task_attr = MSG_HEAD_TAG;
break;
case FCP_PTA_ORDERED:
task_attr = MSG_ORDERED_TAG;
break;
case FCP_PTA_ACA:
task_attr = MSG_ACA_TAG;
break;
case FCP_PTA_SIMPLE: /* Fallthrough */
default:
task_attr = MSG_SIMPLE_TAG;
}
task_attr = fcp->fc_pri_ta & FCP_PTA_MASK;
data_len = ntohl(fcp->fc_dl);
cmd->cdb = fcp->fc_cdb;
}
se_cmd = &cmd->se_cmd;
/*
* Initialize struct se_cmd descriptor from target_core_mod
* infrastructure
*/
transport_init_se_cmd(se_cmd, &ft_configfs->tf_ops, cmd->sess->se_sess,
data_len, data_dir, task_attr,
&cmd->ft_sense_buffer[0]);
/*
* Check for FCP task management flags
*/
if (fcp->fc_tm_flags) {
ft_send_tm(cmd);
return;
}
fc_seq_exch(cmd->seq)->lp->tt.seq_set_resp(cmd->seq, ft_recv_seq, cmd);
cmd->lun = scsilun_to_int((struct scsi_lun *)fcp->fc_lun);
ret = transport_get_lun_for_cmd(&cmd->se_cmd, NULL, cmd->lun);
if (ret < 0) {
ft_dump_cmd(cmd, __func__);
transport_send_check_condition_and_sense(&cmd->se_cmd,
cmd->se_cmd.scsi_sense_reason, 0);
return;
}
ret = transport_generic_allocate_tasks(se_cmd, cmd->cdb);
FT_IO_DBG("r_ctl %x alloc task ret %d\n", fh->fh_r_ctl, ret);
ft_dump_cmd(cmd, __func__);
if (ret == -1) {
transport_send_check_condition_and_sense(se_cmd,
TCM_LOGICAL_UNIT_COMMUNICATION_FAILURE, 0);
transport_generic_free_cmd(se_cmd, 0, 1, 0);
return;
}
if (ret == -2) {
if (se_cmd->se_cmd_flags & SCF_SCSI_RESERVATION_CONFLICT)
ft_queue_status(se_cmd);
else
transport_send_check_condition_and_sense(se_cmd,
se_cmd->scsi_sense_reason, 0);
transport_generic_free_cmd(se_cmd, 0, 1, 0);
return;
}
transport_generic_handle_cdb(se_cmd);
return;
err:
ft_send_resp_code(cmd, FCP_CMND_FIELDS_INVALID);
return;
}
