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 000000000000..4c3c0efbe13f --- /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/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 <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/target_core_base.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 se_transport_task *task; + struct fc_frame *fp = NULL; + struct fc_exch *ep; + struct fc_lport *lport; + struct se_mem *mem; + size_t remaining; + u32 f_ctl = FC_FC_EX_CTX | FC_FC_REL_OFF; + u32 mem_off; + u32 fh_off = 0; + u32 frame_off = 0; + size_t frame_len = 0; + size_t mem_len; + size_t tlen; + size_t off_in_page; + struct page *page; + 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); + + task = T_TASK(se_cmd); + BUG_ON(!task); + remaining = se_cmd->data_length; + + /* + * Setup to use first mem list entry if any. + */ + if (task->t_tasks_se_num) { + mem = list_first_entry(task->t_mem_list, + struct se_mem, se_list); + mem_len = mem->se_len; + mem_off = mem->se_off; + page = mem->se_page; + } else { + mem = NULL; + mem_len = remaining; + mem_off = 0; + page = NULL; + } + + /* no scatter/gather in skb for odd word length due to fc_seq_send() */ + use_sg = !(remaining % 4); + + while (remaining) { + if (!mem_len) { + BUG_ON(!mem); + mem = list_entry(mem->se_list.next, + struct se_mem, se_list); + mem_len = min((size_t)mem->se_len, remaining); + mem_off = mem->se_off; + page = mem->se_page; + } + 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) { + if (!mem) { + BUG_ON(!task->t_task_buf); + page_addr = task->t_task_buf + mem_off; + /* + * In this case, offset is 'offset_in_page' of + * (t_task_buf + mem_off) instead of 'mem_off'. + */ + off_in_page = offset_in_page(page_addr); + page = virt_to_page(page_addr); + tlen = min(tlen, PAGE_SIZE - off_in_page); + } else + 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 if (mem) { + 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; + } else { + from = task->t_task_buf + mem_off; + memcpy(to, from, tlen); + 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 */ + if (printk_ratelimit()) + printk(KERN_ERR "%s: Failed to send frame %p, " + "xid <0x%x>, remaining <0x%x>, " + "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 se_transport_task *task; + struct fc_frame_header *fh; + struct se_mem *mem; + u32 mem_off; + u32 rel_off; + size_t frame_len; + size_t mem_len; + size_t tlen; + struct page *page; + void *page_addr; + void *from; + void *to; + u32 f_ctl; + void *buf; + + task = T_TASK(se_cmd); + BUG_ON(!task); + + 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) { + printk(KERN_INFO "%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 + */ + printk(KERN_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 if any. + */ + if (task->t_tasks_se_num) { + mem = list_first_entry(task->t_mem_list, + struct se_mem, se_list); + mem_len = mem->se_len; + mem_off = mem->se_off; + page = mem->se_page; + } else { + mem = NULL; + page = NULL; + mem_off = 0; + mem_len = frame_len; + } + + while (frame_len) { + if (!mem_len) { + BUG_ON(!mem); + mem = list_entry(mem->se_list.next, + struct se_mem, se_list); + mem_len = mem->se_len; + mem_off = mem->se_off; + page = mem->se_page; + } + 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); + + if (mem) { + 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); + } else { + to = task->t_task_buf + mem_off; + memcpy(to, from, tlen); + } + 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); +} |