--- /dev/null
+/*
+ * 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);
+}
git.openpandora.org / pandora-kernel.git / blobdiff