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