drivers/target/tcm_fc/tfc_io.c

   1 /*
   2  * Copyright (c) 2010 Cisco Systems, Inc.
   3  *
   4  * Portions based on tcm_loop_fabric_scsi.c and libfc/fc_fcp.c
   5  *
   6  * Copyright (c) 2007 Intel Corporation. All rights reserved.
   7  * Copyright (c) 2008 Red Hat, Inc.  All rights reserved.
   8  * Copyright (c) 2008 Mike Christie
   9  * Copyright (c) 2009 Rising Tide, Inc.
  10  * Copyright (c) 2009 Linux-iSCSI.org
  11  * Copyright (c) 2009 Nicholas A. Bellinger <nab@linux-iscsi.org>
  12  *
  13  * This program is free software; you can redistribute it and/or modify it
  14  * under the terms and conditions of the GNU General Public License,
  15  * version 2, as published by the Free Software Foundation.
  16  *
  17  * This program is distributed in the hope it will be useful, but WITHOUT
  18  * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
  19  * FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License for
  20  * more details.
  21  *
  22  * You should have received a copy of the GNU General Public License along with
  23  * this program; if not, write to the Free Software Foundation, Inc.,
  24  * 51 Franklin St - Fifth Floor, Boston, MA 02110-1301 USA.
  25  */
  26
  27 /* XXX TBD some includes may be extraneous */
  28
  29 #include <linux/module.h>
  30 #include <linux/moduleparam.h>
  31 #include <linux/version.h>
  32 #include <generated/utsrelease.h>
  33 #include <linux/utsname.h>
  34 #include <linux/init.h>
  35 #include <linux/slab.h>
  36 #include <linux/kthread.h>
  37 #include <linux/types.h>
  38 #include <linux/string.h>
  39 #include <linux/configfs.h>
  40 #include <linux/ctype.h>
  41 #include <linux/hash.h>
  42 #include <linux/ratelimit.h>
  43 #include <asm/unaligned.h>
  44 #include <scsi/scsi.h>
  45 #include <scsi/scsi_host.h>
  46 #include <scsi/scsi_device.h>
  47 #include <scsi/scsi_cmnd.h>
  48 #include <scsi/libfc.h>
  49 #include <scsi/fc_encode.h>
  50
  51 #include <target/target_core_base.h>
  52 #include <target/target_core_transport.h>
  53 #include <target/target_core_fabric_ops.h>
  54 #include <target/target_core_device.h>
  55 #include <target/target_core_tpg.h>
  56 #include <target/target_core_configfs.h>
  57 #include <target/configfs_macros.h>
  58
  59 #include "tcm_fc.h"
  60
  61 /*
  62  * Deliver read data back to initiator.
  63  * XXX TBD handle resource problems later.
  64  */
  65 int ft_queue_data_in(struct se_cmd *se_cmd)
  66 {
  67         struct ft_cmd *cmd = container_of(se_cmd, struct ft_cmd, se_cmd);
  68         struct fc_frame *fp = NULL;
  69         struct fc_exch *ep;
  70         struct fc_lport *lport;
  71         struct scatterlist *sg = NULL;
  72         size_t remaining;
  73         u32 f_ctl = FC_FC_EX_CTX | FC_FC_REL_OFF;
  74         u32 mem_off = 0;
  75         u32 fh_off = 0;
  76         u32 frame_off = 0;
  77         size_t frame_len = 0;
  78         size_t mem_len = 0;
  79         size_t tlen;
  80         size_t off_in_page;
  81         struct page *page = NULL;
  82         int use_sg;
  83         int error;
  84         void *page_addr;
  85         void *from;
  86         void *to = NULL;
  87
  88         ep = fc_seq_exch(cmd->seq);
  89         lport = ep->lp;
  90         cmd->seq = lport->tt.seq_start_next(cmd->seq);
  91
  92         remaining = se_cmd->data_length;
  93
  94         /*
  95          * Setup to use first mem list entry, unless no data.
  96          */
  97         BUG_ON(remaining && !se_cmd->t_data_sg);
  98         if (remaining) {
  99                 sg = se_cmd->t_data_sg;
 100                 mem_len = sg->length;
 101                 mem_off = sg->offset;
 102                 page = sg_page(sg);
 103         }
 104
 105         /* no scatter/gather in skb for odd word length due to fc_seq_send() */
 106         use_sg = !(remaining % 4);
 107
 108         while (remaining) {
 109                 if (!mem_len) {
 110                         sg = sg_next(sg);
 111                         mem_len = min((size_t)sg->length, remaining);
 112                         mem_off = sg->offset;
 113                         page = sg_page(sg);
 114                 }
 115                 if (!frame_len) {
 116                         /*
 117                          * If lport's has capability of Large Send Offload LSO)
 118                          * , then allow 'frame_len' to be as big as 'lso_max'
 119                          * if indicated transfer length is >= lport->lso_max
 120                          */
 121                         frame_len = (lport->seq_offload) ? lport->lso_max :
 122                                                           cmd->sess->max_frame;
 123                         frame_len = min(frame_len, remaining);
 124                         fp = fc_frame_alloc(lport, use_sg ? 0 : frame_len);
 125                         if (!fp)
 126                                 return -ENOMEM;
 127                         to = fc_frame_payload_get(fp, 0);
 128                         fh_off = frame_off;
 129                         frame_off += frame_len;
 130                         /*
 131                          * Setup the frame's max payload which is used by base
 132                          * driver to indicate HW about max frame size, so that
 133                          * HW can do fragmentation appropriately based on
 134                          * "gso_max_size" of underline netdev.
 135                          */
 136                         fr_max_payload(fp) = cmd->sess->max_frame;
 137                 }
 138                 tlen = min(mem_len, frame_len);
 139
 140                 if (use_sg) {
 141                         off_in_page = mem_off;
 142                         BUG_ON(!page);
 143                         get_page(page);
 144                         skb_fill_page_desc(fp_skb(fp),
 145                                            skb_shinfo(fp_skb(fp))->nr_frags,
 146                                            page, off_in_page, tlen);
 147                         fr_len(fp) += tlen;
 148                         fp_skb(fp)->data_len += tlen;
 149                         fp_skb(fp)->truesize +=
 150                                         PAGE_SIZE << compound_order(page);
 151                 } else {
 152                         BUG_ON(!page);
 153                         from = kmap_atomic(page + (mem_off >> PAGE_SHIFT),
 154                                            KM_SOFTIRQ0);
 155                         page_addr = from;
 156                         from += mem_off & ~PAGE_MASK;
 157                         tlen = min(tlen, (size_t)(PAGE_SIZE -
 158                                                 (mem_off & ~PAGE_MASK)));
 159                         memcpy(to, from, tlen);
 160                         kunmap_atomic(page_addr, KM_SOFTIRQ0);
 161                         to += tlen;
 162                 }
 163
 164                 mem_off += tlen;
 165                 mem_len -= tlen;
 166                 frame_len -= tlen;
 167                 remaining -= tlen;
 168
 169                 if (frame_len &&
 170                     (skb_shinfo(fp_skb(fp))->nr_frags < FC_FRAME_SG_LEN))
 171                         continue;
 172                 if (!remaining)
 173                         f_ctl |= FC_FC_END_SEQ;
 174                 fc_fill_fc_hdr(fp, FC_RCTL_DD_SOL_DATA, ep->did, ep->sid,
 175                                FC_TYPE_FCP, f_ctl, fh_off);
 176                 error = lport->tt.seq_send(lport, cmd->seq, fp);
 177                 if (error) {
 178                         /* XXX For now, initiator will retry */
 179                         pr_err_ratelimited("%s: Failed to send frame %p, "
 180                                                 "xid <0x%x>, remaining %zu, "
 181                                                 "lso_max <0x%x>\n",
 182                                                 __func__, fp, ep->xid,
 183                                                 remaining, lport->lso_max);
 184                 }
 185         }
 186         return ft_queue_status(se_cmd);
 187 }
 188
 189 /*
 190  * Receive write data frame.
 191  */
 192 void ft_recv_write_data(struct ft_cmd *cmd, struct fc_frame *fp)
 193 {
 194         struct se_cmd *se_cmd = &cmd->se_cmd;
 195         struct fc_seq *seq = cmd->seq;
 196         struct fc_exch *ep;
 197         struct fc_lport *lport;
 198         struct fc_frame_header *fh;
 199         struct scatterlist *sg = NULL;
 200         u32 mem_off = 0;
 201         u32 rel_off;
 202         size_t frame_len;
 203         size_t mem_len = 0;
 204         size_t tlen;
 205         struct page *page = NULL;
 206         void *page_addr;
 207         void *from;
 208         void *to;
 209         u32 f_ctl;
 210         void *buf;
 211
 212         fh = fc_frame_header_get(fp);
 213         if (!(ntoh24(fh->fh_f_ctl) & FC_FC_REL_OFF))
 214                 goto drop;
 215
 216         f_ctl = ntoh24(fh->fh_f_ctl);
 217         ep = fc_seq_exch(seq);
 218         lport = ep->lp;
 219         if (cmd->was_ddp_setup) {
 220                 BUG_ON(!ep);
 221                 BUG_ON(!lport);
 222                 /*
 223                  * Since DDP (Large Rx offload) was setup for this request,
 224                  * payload is expected to be copied directly to user buffers.
 225                  */
 226                 buf = fc_frame_payload_get(fp, 1);
 227                 if (buf)
 228                         pr_err("%s: xid 0x%x, f_ctl 0x%x, cmd->sg %p, "
 229                                 "cmd->sg_cnt 0x%x. DDP was setup"
 230                                 " hence not expected to receive frame with "
 231                                 "payload, Frame will be dropped if"
 232                                 "'Sequence Initiative' bit in f_ctl is"
 233                                 "not set\n", __func__, ep->xid, f_ctl,
 234                                 cmd->sg, cmd->sg_cnt);
 235                 /*
 236                  * Invalidate HW DDP context if it was setup for respective
 237                  * command. Invalidation of HW DDP context is requited in both
 238                  * situation (success and error).
 239                  */
 240                 ft_invl_hw_context(cmd);
 241
 242                 /*
 243                  * If "Sequence Initiative (TSI)" bit set in f_ctl, means last
 244                  * write data frame is received successfully where payload is
 245                  * posted directly to user buffer and only the last frame's
 246                  * header is posted in receive queue.
 247                  *
 248                  * If "Sequence Initiative (TSI)" bit is not set, means error
 249                  * condition w.r.t. DDP, hence drop the packet and let explict
 250                  * ABORTS from other end of exchange timer trigger the recovery.
 251                  */
 252                 if (f_ctl & FC_FC_SEQ_INIT)
 253                         goto last_frame;
 254                 else
 255                         goto drop;
 256         }
 257
 258         rel_off = ntohl(fh->fh_parm_offset);
 259         frame_len = fr_len(fp);
 260         if (frame_len <= sizeof(*fh))
 261                 goto drop;
 262         frame_len -= sizeof(*fh);
 263         from = fc_frame_payload_get(fp, 0);
 264         if (rel_off >= se_cmd->data_length)
 265                 goto drop;
 266         if (frame_len + rel_off > se_cmd->data_length)
 267                 frame_len = se_cmd->data_length - rel_off;
 268
 269         /*
 270          * Setup to use first mem list entry, unless no data.
 271          */
 272         BUG_ON(frame_len && !se_cmd->t_data_sg);
 273         if (frame_len) {
 274                 sg = se_cmd->t_data_sg;
 275                 mem_len = sg->length;
 276                 mem_off = sg->offset;
 277                 page = sg_page(sg);
 278         }
 279
 280         while (frame_len) {
 281                 if (!mem_len) {
 282                         sg = sg_next(sg);
 283                         mem_len = sg->length;
 284                         mem_off = sg->offset;
 285                         page = sg_page(sg);
 286                 }
 287                 if (rel_off >= mem_len) {
 288                         rel_off -= mem_len;
 289                         mem_len = 0;
 290                         continue;
 291                 }
 292                 mem_off += rel_off;
 293                 mem_len -= rel_off;
 294                 rel_off = 0;
 295
 296                 tlen = min(mem_len, frame_len);
 297
 298                 to = kmap_atomic(page + (mem_off >> PAGE_SHIFT),
 299                                  KM_SOFTIRQ0);
 300                 page_addr = to;
 301                 to += mem_off & ~PAGE_MASK;
 302                 tlen = min(tlen, (size_t)(PAGE_SIZE -
 303                                           (mem_off & ~PAGE_MASK)));
 304                 memcpy(to, from, tlen);
 305                 kunmap_atomic(page_addr, KM_SOFTIRQ0);
 306
 307                 from += tlen;
 308                 frame_len -= tlen;
 309                 mem_off += tlen;
 310                 mem_len -= tlen;
 311                 cmd->write_data_len += tlen;
 312         }
 313 last_frame:
 314         if (cmd->write_data_len == se_cmd->data_length)
 315                 transport_generic_handle_data(se_cmd);
 316 drop:
 317         fc_frame_free(fp);
 318 }
 319
 320 /*
 321  * Handle and cleanup any HW specific resources if
 322  * received ABORTS, errors, timeouts.
 323  */
 324 void ft_invl_hw_context(struct ft_cmd *cmd)
 325 {
 326         struct fc_seq *seq = cmd->seq;
 327         struct fc_exch *ep = NULL;
 328         struct fc_lport *lport = NULL;
 329
 330         BUG_ON(!cmd);
 331
 332         /* Cleanup the DDP context in HW if DDP was setup */
 333         if (cmd->was_ddp_setup && seq) {
 334                 ep = fc_seq_exch(seq);
 335                 if (ep) {
 336                         lport = ep->lp;
 337                         if (lport && (ep->xid <= lport->lro_xid))
 338                                 /*
 339                                  * "ddp_done" trigger invalidation of HW
 340                                  * specific DDP context
 341                                  */
 342                                 cmd->write_data_len = lport->tt.ddp_done(lport,
 343                                                                       ep->xid);
 344
 345                                 /*
 346                                  * Resetting same variable to indicate HW's
 347                                  * DDP context has been invalidated to avoid
 348                                  * re_invalidation of same context (context is
 349                                  * identified using ep->xid)
 350                                  */
 351                                 cmd->was_ddp_setup = 0;
 352                 }
 353         }
 354 }