diff options
Diffstat (limited to 'drivers/target/tcm_fc/tfc_io.c')
| -rw-r--r-- | drivers/target/tcm_fc/tfc_io.c | 374 |
1 files changed, 374 insertions, 0 deletions
diff --git a/drivers/target/tcm_fc/tfc_io.c b/drivers/target/tcm_fc/tfc_io.c new file mode 100644 index 000000000..1eb1f58e0 --- /dev/null +++ b/drivers/target/tcm_fc/tfc_io.c @@ -0,0 +1,374 @@ +/* + * 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/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/libfc.h> +#include <scsi/fc_encode.h> + +#include <target/target_core_base.h> +#include <target/target_core_fabric.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; + + 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 = fc_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 += offset_in_page(mem_off); + tlen = min(tlen, (size_t)(PAGE_SIZE - + offset_in_page(mem_off))); + 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 = fc_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); +} + +static void ft_execute_work(struct work_struct *work) +{ + struct ft_cmd *cmd = container_of(work, struct ft_cmd, work); + + target_execute_cmd(&cmd->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; + + f_ctl = ntoh24(fh->fh_f_ctl); + ep = fc_seq_exch(seq); + lport = ep->lp; + if (cmd->was_ddp_setup) { + BUG_ON(!ep); + BUG_ON(!lport); + /* + * Since DDP (Large Rx offload) was setup for this request, + * payload is expected to be copied directly to user buffers. + */ + buf = fc_frame_payload_get(fp, 1); + if (buf) + pr_err("%s: xid 0x%x, f_ctl 0x%x, cmd->sg %p, " + "cmd->sg_cnt 0x%x. DDP was setup" + " hence not expected to receive frame with " + "payload, Frame will be dropped if" + "'Sequence Initiative' bit in f_ctl is" + "not set\n", __func__, ep->xid, f_ctl, + se_cmd->t_data_sg, se_cmd->t_data_nents); + /* + * Invalidate HW DDP context if it was setup for respective + * command. Invalidation of HW DDP context is requited in both + * situation (success and error). + */ + ft_invl_hw_context(cmd); + + /* + * If "Sequence Initiative (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 receive queue. + * + * If "Sequence Initiative (TSI)" bit is not set, means error + * condition w.r.t. DDP, hence drop the packet and let explict + * ABORTS from other end of exchange timer trigger the recovery. + */ + if (f_ctl & FC_FC_SEQ_INIT) + goto last_frame; + else + 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)); + page_addr = to; + to += offset_in_page(mem_off); + tlen = min(tlen, (size_t)(PAGE_SIZE - + offset_in_page(mem_off))); + memcpy(to, from, tlen); + kunmap_atomic(page_addr); + + 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) { + INIT_WORK(&cmd->work, ft_execute_work); + queue_work(cmd->sess->tport->tpg->workqueue, &cmd->work); + } +drop: + fc_frame_free(fp); +} + +/* + * Handle and cleanup any HW specific resources if + * received ABORTS, errors, timeouts. + */ +void ft_invl_hw_context(struct ft_cmd *cmd) +{ + struct fc_seq *seq; + struct fc_exch *ep = NULL; + struct fc_lport *lport = NULL; + + BUG_ON(!cmd); + seq = cmd->seq; + + /* Cleanup the DDP context in HW if DDP was setup */ + if (cmd->was_ddp_setup && seq) { + ep = fc_seq_exch(seq); + if (ep) { + lport = ep->lp; + if (lport && (ep->xid <= lport->lro_xid)) { + /* + * "ddp_done" trigger invalidation of HW + * specific DDP context + */ + cmd->write_data_len = lport->tt.ddp_done(lport, + ep->xid); + + /* + * Resetting same variable to indicate HW's + * DDP context has been invalidated to avoid + * re_invalidation of same context (context is + * identified using ep->xid) + */ + cmd->was_ddp_setup = 0; + } + } + } +} |