/*
* Copyright (c) 2010 Cisco Systems, Inc.
*
* Portions based on tcm_loop_fabric_scsi.c and libfc/fc_fcp.c
*
* Copyright (c) 2007 Intel Corporation. All rights reserved.
* Copyright (c) 2008 Red Hat, Inc. All rights reserved.
* Copyright (c) 2008 Mike Christie
* Copyright (c) 2009 Rising Tide, Inc.
* Copyright (c) 2009 Linux-iSCSI.org
* Copyright (c) 2009 Nicholas A. Bellinger <nab@linux-iscsi.org>
*
* This program is free software; you can redistribute it and/or modify it
* under the terms and conditions of the GNU General Public License,
* version 2, as published by the Free Software Foundation.
*
* This program is distributed in the hope it will be useful, but WITHOUT
* ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
* FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License for
* more details.
*
* You should have received a copy of the GNU General Public License along with
* this program; if not, write to the Free Software Foundation, Inc.,
* 51 Franklin St - Fifth Floor, Boston, MA 02110-1301 USA.
*/
/* XXX TBD some includes may be extraneous */
#include <linux/module.h>
#include <linux/moduleparam.h>
#include <linux/version.h>
#include <generated/utsrelease.h>
#include <linux/utsname.h>
#include <linux/init.h>
#include <linux/slab.h>
#include <linux/kthread.h>
#include <linux/types.h>
#include <linux/string.h>
#include <linux/configfs.h>
#include <linux/ctype.h>
#include <linux/hash.h>
#include <linux/ratelimit.h>
#include <asm/unaligned.h>
#include <scsi/scsi.h>
#include <scsi/scsi_host.h>
#include <scsi/scsi_device.h>
#include <scsi/scsi_cmnd.h>
#include <scsi/libfc.h>
#include <scsi/fc_encode.h>
#include <target/target_core_base.h>
#include <target/target_core_transport.h>
#include <target/target_core_fabric_ops.h>
#include <target/target_core_device.h>
#include <target/target_core_tpg.h>
#include <target/target_core_configfs.h>
#include <target/configfs_macros.h>
#include "tcm_fc.h"
/*
* 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;
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) {
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),
KM_SOFTIRQ0);
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, KM_SOFTIRQ0);
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, cmd->seq, fp);
if (error) {
/* XXX For now, initiator will retry */
pr_err_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);
}
}
return ft_queue_status(se_cmd);
}
/*
* Receive write data frame.
*/
void ft_recv_write_data(struct ft_cmd *cmd, struct fc_frame *fp)
{
struct se_cmd *se_cmd = &cmd->se_cmd;
struct fc_seq *seq = cmd->seq;
struct fc_exch *ep;
struct fc_lport *lport;
struct fc_frame_header *fh;
struct scatterlist *sg = NULL;
u32 mem_off = 0;
u32 rel_off;
size_t frame_len;
size_t mem_len = 0;
size_t tlen;
struct page *page = NULL;
void *page_addr;
void *from;
void *to;
u32 f_ctl;
void *buf;
fh = fc_frame_header_get(fp);
if (!(ntoh24(fh->fh_f_ctl) & FC_FC_REL_OFF))
goto drop;
/*
* Doesn't expect even single byte of payload. Payload
* is expected to be copied directly to user buffers
* due to DDP (Large Rx offload) feature, hence
* BUG_ON if BUF is non-NULL
*/
buf = fc_frame_payload_get(fp, 1);
if (cmd->was_ddp_setup && buf) {
pr_debug("%s: When DDP was setup, not expected to"
"receive frame with payload, Payload shall be"
"copied directly to buffer instead of coming "
"via. legacy receive queues\n", __func__);
BUG_ON(buf);
}
/*
* If ft_cmd indicated 'ddp_setup', in that case only the last frame
* should come with 'TSI bit being set'. If 'TSI bit is not set and if
* data frame appears here, means error condition. In both the cases
* release the DDP context (ddp_put) and in error case, as well
* initiate error recovery mechanism.
*/
ep = fc_seq_exch(seq);
if (cmd->was_ddp_setup) {
BUG_ON(!ep);
lport = ep->lp;
BUG_ON(!lport);
}
if (cmd->was_ddp_setup && ep->xid != FC_XID_UNKNOWN) {
f_ctl = ntoh24(fh->fh_f_ctl);
/*
* If TSI bit set in f_ctl, means last write data frame is
* received successfully where payload is posted directly
* to user buffer and only the last frame's header is posted
* in legacy receive queue
*/
if (f_ctl & FC_FC_SEQ_INIT) { /* TSI bit set in FC frame */
cmd->write_data_len = lport->tt.ddp_done(lport,
ep->xid);
goto last_frame;
} else {
/*
* Updating the write_data_len may be meaningless at
* this point, but just in case if required in future
* for debugging or any other purpose
*/
pr_err("%s: Received frame with TSI bit not"
" being SET, dropping the frame, "
"cmd->sg <%p>, cmd->sg_cnt <0x%x>\n",
__func__, cmd->sg, cmd->sg_cnt);
cmd->write_data_len = lport->tt.ddp_done(lport,
ep->xid);
lport->tt.seq_exch_abort(cmd->seq, 0);
goto drop;
}
}
rel_off = ntohl(fh->fh_parm_offset);
frame_len = fr_len(fp);
if (frame_len <= sizeof(*fh))
goto drop;
frame_len -= sizeof(*fh);
from = fc_frame_payload_get(fp, 0);
if (rel_off >= se_cmd->data_length)
goto drop;
if (frame_len + rel_off > se_cmd->data_length)
frame_len = se_cmd->data_length - rel_off;
/*
* Setup to use first mem list entry, unless no data.
*/
BUG_ON(frame_len && !se_cmd->t_data_sg);
if (frame_len) {
sg = se_cmd->t_data_sg;
mem_len = sg->length;
mem_off = sg->offset;
page = sg_page(sg);
}
while (frame_len) {
if (!mem_len) {
sg = sg_next(sg);
mem_len = sg->length;
mem_off = sg->offset;
page = sg_page(sg);
}
if (rel_off >= mem_len) {
rel_off -= mem_len;
mem_len = 0;
continue;
}
mem_off += rel_off;
mem_len -= rel_off;
rel_off = 0;
tlen = min(mem_len, frame_len);
to = kmap_atomic(page + (mem_off >> PAGE_SHIFT),
KM_SOFTIRQ0);
page_addr = to;
to += mem_off & ~PAGE_MASK;
tlen = min(tlen, (size_t)(PAGE_SIZE -
(mem_off & ~PAGE_MASK)));
memcpy(to, from, tlen);
kunmap_atomic(page_addr, KM_SOFTIRQ0);
from += tlen;
frame_len -= tlen;
mem_off += tlen;
mem_len -= tlen;
cmd->write_data_len += tlen;
}
last_frame:
if (cmd->write_data_len == se_cmd->data_length)
transport_generic_handle_data(se_cmd);
drop:
fc_frame_free(fp);
}
