drivers/infiniband/sw/siw/siw_qp

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This source file includes following definitions.
siw_try_1seg
siw_qp_prepare_tx
siw_tx_ctrl
siw_tcp_sendpages
siw_0copy_tx
siw_unmap_pages
siw_tx_hdt
siw_update_tcpseg
siw_prepare_fpdu
siw_check_sgl_tx
siw_qp_sq_proc_tx
siw_fastreg_mr
siw_qp_sq_proc_local
siw_qp_sq_process
siw_sq_resume
siw_stop_tx_thread
siw_run_sq
siw_sq_start
   1 // SPDX-License-Identifier: GPL-2.0 or BSD-3-Clause
   2 
   3 /* Authors: Bernard Metzler <bmt@zurich.ibm.com> */
   4 /* Copyright (c) 2008-2019, IBM Corporation */
   5 
   6 #include <linux/errno.h>
   7 #include <linux/types.h>
   8 #include <linux/net.h>
   9 #include <linux/scatterlist.h>
  10 #include <linux/highmem.h>
  11 #include <net/tcp.h>
  12 
  13 #include <rdma/iw_cm.h>
  14 #include <rdma/ib_verbs.h>
  15 #include <rdma/ib_user_verbs.h>
  16 
  17 #include "siw.h"
  18 #include "siw_verbs.h"
  19 #include "siw_mem.h"
  20 
  21 #define MAX_HDR_INLINE                                  \
  22         (((uint32_t)(sizeof(struct siw_rreq_pkt) -      \
  23                      sizeof(struct iwarp_send))) & 0xF8)
  24 
  25 static struct page *siw_get_pblpage(struct siw_mem *mem, u64 addr, int *idx)
  26 {
  27         struct siw_pbl *pbl = mem->pbl;
  28         u64 offset = addr - mem->va;
  29         dma_addr_t paddr = siw_pbl_get_buffer(pbl, offset, NULL, idx);
  30 
  31         if (paddr)
  32                 return virt_to_page(paddr);
  33 
  34         return NULL;
  35 }
  36 
  37 /*
  38  * Copy short payload at provided destination payload address
  39  */
  40 static int siw_try_1seg(struct siw_iwarp_tx *c_tx, void *paddr)
  41 {
  42         struct siw_wqe *wqe = &c_tx->wqe_active;
  43         struct siw_sge *sge = &wqe->sqe.sge[0];
  44         u32 bytes = sge->length;
  45 
  46         if (bytes > MAX_HDR_INLINE || wqe->sqe.num_sge != 1)
  47                 return MAX_HDR_INLINE + 1;
  48 
  49         if (!bytes)
  50                 return 0;
  51 
  52         if (tx_flags(wqe) & SIW_WQE_INLINE) {
  53                 memcpy(paddr, &wqe->sqe.sge[1], bytes);
  54         } else {
  55                 struct siw_mem *mem = wqe->mem[0];
  56 
  57                 if (!mem->mem_obj) {
  58                         /* Kernel client using kva */
  59                         memcpy(paddr,
  60                                (const void *)(uintptr_t)sge->laddr, bytes);
  61                 } else if (c_tx->in_syscall) {
  62                         if (copy_from_user(paddr, u64_to_user_ptr(sge->laddr),
  63                                            bytes))
  64                                 return -EFAULT;
  65                 } else {
  66                         unsigned int off = sge->laddr & ~PAGE_MASK;
  67                         struct page *p;
  68                         char *buffer;
  69                         int pbl_idx = 0;
  70 
  71                         if (!mem->is_pbl)
  72                                 p = siw_get_upage(mem->umem, sge->laddr);
  73                         else
  74                                 p = siw_get_pblpage(mem, sge->laddr, &pbl_idx);
  75 
  76                         if (unlikely(!p))
  77                                 return -EFAULT;
  78 
  79                         buffer = kmap(p);
  80 
  81                         if (likely(PAGE_SIZE - off >= bytes)) {
  82                                 memcpy(paddr, buffer + off, bytes);
  83                         } else {
  84                                 unsigned long part = bytes - (PAGE_SIZE - off);
  85 
  86                                 memcpy(paddr, buffer + off, part);
  87                                 kunmap(p);
  88 
  89                                 if (!mem->is_pbl)
  90                                         p = siw_get_upage(mem->umem,
  91                                                           sge->laddr + part);
  92                                 else
  93                                         p = siw_get_pblpage(mem,
  94                                                             sge->laddr + part,
  95                                                             &pbl_idx);
  96                                 if (unlikely(!p))
  97                                         return -EFAULT;
  98 
  99                                 buffer = kmap(p);
 100                                 memcpy(paddr + part, buffer, bytes - part);
 101                         }
 102                         kunmap(p);
 103                 }
 104         }
 105         return (int)bytes;
 106 }
 107 
 108 #define PKT_FRAGMENTED 1
 109 #define PKT_COMPLETE 0
 110 
 111 /*
 112  * siw_qp_prepare_tx()
 113  *
 114  * Prepare tx state for sending out one fpdu. Builds complete pkt
 115  * if no user data or only immediate data are present.
 116  *
 117  * returns PKT_COMPLETE if complete pkt built, PKT_FRAGMENTED otherwise.
 118  */
 119 static int siw_qp_prepare_tx(struct siw_iwarp_tx *c_tx)
 120 {
 121         struct siw_wqe *wqe = &c_tx->wqe_active;
 122         char *crc = NULL;
 123         int data = 0;
 124 
 125         switch (tx_type(wqe)) {
 126         case SIW_OP_READ:
 127         case SIW_OP_READ_LOCAL_INV:
 128                 memcpy(&c_tx->pkt.ctrl,
 129                        &iwarp_pktinfo[RDMAP_RDMA_READ_REQ].ctrl,
 130                        sizeof(struct iwarp_ctrl));
 131 
 132                 c_tx->pkt.rreq.rsvd = 0;
 133                 c_tx->pkt.rreq.ddp_qn = htonl(RDMAP_UNTAGGED_QN_RDMA_READ);
 134                 c_tx->pkt.rreq.ddp_msn =
 135                         htonl(++c_tx->ddp_msn[RDMAP_UNTAGGED_QN_RDMA_READ]);
 136                 c_tx->pkt.rreq.ddp_mo = 0;
 137                 c_tx->pkt.rreq.sink_stag = htonl(wqe->sqe.sge[0].lkey);
 138                 c_tx->pkt.rreq.sink_to =
 139                         cpu_to_be64(wqe->sqe.sge[0].laddr);
 140                 c_tx->pkt.rreq.source_stag = htonl(wqe->sqe.rkey);
 141                 c_tx->pkt.rreq.source_to = cpu_to_be64(wqe->sqe.raddr);
 142                 c_tx->pkt.rreq.read_size = htonl(wqe->sqe.sge[0].length);
 143 
 144                 c_tx->ctrl_len = sizeof(struct iwarp_rdma_rreq);
 145                 crc = (char *)&c_tx->pkt.rreq_pkt.crc;
 146                 break;
 147 
 148         case SIW_OP_SEND:
 149                 if (tx_flags(wqe) & SIW_WQE_SOLICITED)
 150                         memcpy(&c_tx->pkt.ctrl,
 151                                &iwarp_pktinfo[RDMAP_SEND_SE].ctrl,
 152                                sizeof(struct iwarp_ctrl));
 153                 else
 154                         memcpy(&c_tx->pkt.ctrl, &iwarp_pktinfo[RDMAP_SEND].ctrl,
 155                                sizeof(struct iwarp_ctrl));
 156 
 157                 c_tx->pkt.send.ddp_qn = RDMAP_UNTAGGED_QN_SEND;
 158                 c_tx->pkt.send.ddp_msn =
 159                         htonl(++c_tx->ddp_msn[RDMAP_UNTAGGED_QN_SEND]);
 160                 c_tx->pkt.send.ddp_mo = 0;
 161 
 162                 c_tx->pkt.send_inv.inval_stag = 0;
 163 
 164                 c_tx->ctrl_len = sizeof(struct iwarp_send);
 165 
 166                 crc = (char *)&c_tx->pkt.send_pkt.crc;
 167                 data = siw_try_1seg(c_tx, crc);
 168                 break;
 169 
 170         case SIW_OP_SEND_REMOTE_INV:
 171                 if (tx_flags(wqe) & SIW_WQE_SOLICITED)
 172                         memcpy(&c_tx->pkt.ctrl,
 173                                &iwarp_pktinfo[RDMAP_SEND_SE_INVAL].ctrl,
 174                                sizeof(struct iwarp_ctrl));
 175                 else
 176                         memcpy(&c_tx->pkt.ctrl,
 177                                &iwarp_pktinfo[RDMAP_SEND_INVAL].ctrl,
 178                                sizeof(struct iwarp_ctrl));
 179 
 180                 c_tx->pkt.send.ddp_qn = RDMAP_UNTAGGED_QN_SEND;
 181                 c_tx->pkt.send.ddp_msn =
 182                         htonl(++c_tx->ddp_msn[RDMAP_UNTAGGED_QN_SEND]);
 183                 c_tx->pkt.send.ddp_mo = 0;
 184 
 185                 c_tx->pkt.send_inv.inval_stag = cpu_to_be32(wqe->sqe.rkey);
 186 
 187                 c_tx->ctrl_len = sizeof(struct iwarp_send_inv);
 188 
 189                 crc = (char *)&c_tx->pkt.send_pkt.crc;
 190                 data = siw_try_1seg(c_tx, crc);
 191                 break;
 192 
 193         case SIW_OP_WRITE:
 194                 memcpy(&c_tx->pkt.ctrl, &iwarp_pktinfo[RDMAP_RDMA_WRITE].ctrl,
 195                        sizeof(struct iwarp_ctrl));
 196 
 197                 c_tx->pkt.rwrite.sink_stag = htonl(wqe->sqe.rkey);
 198                 c_tx->pkt.rwrite.sink_to = cpu_to_be64(wqe->sqe.raddr);
 199                 c_tx->ctrl_len = sizeof(struct iwarp_rdma_write);
 200 
 201                 crc = (char *)&c_tx->pkt.write_pkt.crc;
 202                 data = siw_try_1seg(c_tx, crc);
 203                 break;
 204 
 205         case SIW_OP_READ_RESPONSE:
 206                 memcpy(&c_tx->pkt.ctrl,
 207                        &iwarp_pktinfo[RDMAP_RDMA_READ_RESP].ctrl,
 208                        sizeof(struct iwarp_ctrl));
 209 
 210                 /* NBO */
 211                 c_tx->pkt.rresp.sink_stag = cpu_to_be32(wqe->sqe.rkey);
 212                 c_tx->pkt.rresp.sink_to = cpu_to_be64(wqe->sqe.raddr);
 213 
 214                 c_tx->ctrl_len = sizeof(struct iwarp_rdma_rresp);
 215 
 216                 crc = (char *)&c_tx->pkt.write_pkt.crc;
 217                 data = siw_try_1seg(c_tx, crc);
 218                 break;
 219 
 220         default:
 221                 siw_dbg_qp(tx_qp(c_tx), "stale wqe type %d\n", tx_type(wqe));
 222                 return -EOPNOTSUPP;
 223         }
 224         if (unlikely(data < 0))
 225                 return data;
 226 
 227         c_tx->ctrl_sent = 0;
 228 
 229         if (data <= MAX_HDR_INLINE) {
 230                 if (data) {
 231                         wqe->processed = data;
 232 
 233                         c_tx->pkt.ctrl.mpa_len =
 234                                 htons(c_tx->ctrl_len + data - MPA_HDR_SIZE);
 235 
 236                         /* Add pad, if needed */
 237                         data += -(int)data & 0x3;
 238                         /* advance CRC location after payload */
 239                         crc += data;
 240                         c_tx->ctrl_len += data;
 241 
 242                         if (!(c_tx->pkt.ctrl.ddp_rdmap_ctrl & DDP_FLAG_TAGGED))
 243                                 c_tx->pkt.c_untagged.ddp_mo = 0;
 244                         else
 245                                 c_tx->pkt.c_tagged.ddp_to =
 246                                         cpu_to_be64(wqe->sqe.raddr);
 247                 }
 248 
 249                 *(u32 *)crc = 0;
 250                 /*
 251                  * Do complete CRC if enabled and short packet
 252                  */
 253                 if (c_tx->mpa_crc_hd) {
 254                         crypto_shash_init(c_tx->mpa_crc_hd);
 255                         if (crypto_shash_update(c_tx->mpa_crc_hd,
 256                                                 (u8 *)&c_tx->pkt,
 257                                                 c_tx->ctrl_len))
 258                                 return -EINVAL;
 259                         crypto_shash_final(c_tx->mpa_crc_hd, (u8 *)crc);
 260                 }
 261                 c_tx->ctrl_len += MPA_CRC_SIZE;
 262 
 263                 return PKT_COMPLETE;
 264         }
 265         c_tx->ctrl_len += MPA_CRC_SIZE;
 266         c_tx->sge_idx = 0;
 267         c_tx->sge_off = 0;
 268         c_tx->pbl_idx = 0;
 269 
 270         /*
 271          * Allow direct sending out of user buffer if WR is non signalled
 272          * and payload is over threshold.
 273          * Per RDMA verbs, the application should not change the send buffer
 274          * until the work completed. In iWarp, work completion is only
 275          * local delivery to TCP. TCP may reuse the buffer for
 276          * retransmission. Changing unsent data also breaks the CRC,
 277          * if applied.
 278          */
 279         if (c_tx->zcopy_tx && wqe->bytes >= SENDPAGE_THRESH &&
 280             !(tx_flags(wqe) & SIW_WQE_SIGNALLED))
 281                 c_tx->use_sendpage = 1;
 282         else
 283                 c_tx->use_sendpage = 0;
 284 
 285         return PKT_FRAGMENTED;
 286 }
 287 
 288 /*
 289  * Send out one complete control type FPDU, or header of FPDU carrying
 290  * data. Used for fixed sized packets like Read.Requests or zero length
 291  * SENDs, WRITEs, READ.Responses, or header only.
 292  */
 293 static int siw_tx_ctrl(struct siw_iwarp_tx *c_tx, struct socket *s,
 294                               int flags)
 295 {
 296         struct msghdr msg = { .msg_flags = flags };
 297         struct kvec iov = { .iov_base =
 298                                     (char *)&c_tx->pkt.ctrl + c_tx->ctrl_sent,
 299                             .iov_len = c_tx->ctrl_len - c_tx->ctrl_sent };
 300 
 301         int rv = kernel_sendmsg(s, &msg, &iov, 1,
 302                                 c_tx->ctrl_len - c_tx->ctrl_sent);
 303 
 304         if (rv >= 0) {
 305                 c_tx->ctrl_sent += rv;
 306 
 307                 if (c_tx->ctrl_sent == c_tx->ctrl_len)
 308                         rv = 0;
 309                 else
 310                         rv = -EAGAIN;
 311         }
 312         return rv;
 313 }
 314 
 315 /*
 316  * 0copy TCP transmit interface: Use do_tcp_sendpages.
 317  *
 318  * Using sendpage to push page by page appears to be less efficient
 319  * than using sendmsg, even if data are copied.
 320  *
 321  * A general performance limitation might be the extra four bytes
 322  * trailer checksum segment to be pushed after user data.
 323  */
 324 static int siw_tcp_sendpages(struct socket *s, struct page **page, int offset,
 325                              size_t size)
 326 {
 327         struct sock *sk = s->sk;
 328         int i = 0, rv = 0, sent = 0,
 329             flags = MSG_MORE | MSG_DONTWAIT | MSG_SENDPAGE_NOTLAST;
 330 
 331         while (size) {
 332                 size_t bytes = min_t(size_t, PAGE_SIZE - offset, size);
 333 
 334                 if (size + offset <= PAGE_SIZE)
 335                         flags = MSG_MORE | MSG_DONTWAIT;
 336 
 337                 tcp_rate_check_app_limited(sk);
 338 try_page_again:
 339                 lock_sock(sk);
 340                 rv = do_tcp_sendpages(sk, page[i], offset, bytes, flags);
 341                 release_sock(sk);
 342 
 343                 if (rv > 0) {
 344                         size -= rv;
 345                         sent += rv;
 346                         if (rv != bytes) {
 347                                 offset += rv;
 348                                 bytes -= rv;
 349                                 goto try_page_again;
 350                         }
 351                         offset = 0;
 352                 } else {
 353                         if (rv == -EAGAIN || rv == 0)
 354                                 break;
 355                         return rv;
 356                 }
 357                 i++;
 358         }
 359         return sent;
 360 }
 361 
 362 /*
 363  * siw_0copy_tx()
 364  *
 365  * Pushes list of pages to TCP socket. If pages from multiple
 366  * SGE's, all referenced pages of each SGE are pushed in one
 367  * shot.
 368  */
 369 static int siw_0copy_tx(struct socket *s, struct page **page,
 370                         struct siw_sge *sge, unsigned int offset,
 371                         unsigned int size)
 372 {
 373         int i = 0, sent = 0, rv;
 374         int sge_bytes = min(sge->length - offset, size);
 375 
 376         offset = (sge->laddr + offset) & ~PAGE_MASK;
 377 
 378         while (sent != size) {
 379                 rv = siw_tcp_sendpages(s, &page[i], offset, sge_bytes);
 380                 if (rv >= 0) {
 381                         sent += rv;
 382                         if (size == sent || sge_bytes > rv)
 383                                 break;
 384 
 385                         i += PAGE_ALIGN(sge_bytes + offset) >> PAGE_SHIFT;
 386                         sge++;
 387                         sge_bytes = min(sge->length, size - sent);
 388                         offset = sge->laddr & ~PAGE_MASK;
 389                 } else {
 390                         sent = rv;
 391                         break;
 392                 }
 393         }
 394         return sent;
 395 }
 396 
 397 #define MAX_TRAILER (MPA_CRC_SIZE + 4)
 398 
 399 static void siw_unmap_pages(struct page **pp, unsigned long kmap_mask)
 400 {
 401         while (kmap_mask) {
 402                 if (kmap_mask & BIT(0))
 403                         kunmap(*pp);
 404                 pp++;
 405                 kmap_mask >>= 1;
 406         }
 407 }
 408 
 409 /*
 410  * siw_tx_hdt() tries to push a complete packet to TCP where all
 411  * packet fragments are referenced by the elements of one iovec.
 412  * For the data portion, each involved page must be referenced by
 413  * one extra element. All sge's data can be non-aligned to page
 414  * boundaries. Two more elements are referencing iWARP header
 415  * and trailer:
 416  * MAX_ARRAY = 64KB/PAGE_SIZE + 1 + (2 * (SIW_MAX_SGE - 1) + HDR + TRL
 417  */
 418 #define MAX_ARRAY ((0xffff / PAGE_SIZE) + 1 + (2 * (SIW_MAX_SGE - 1) + 2))
 419 
 420 /*
 421  * Write out iov referencing hdr, data and trailer of current FPDU.
 422  * Update transmit state dependent on write return status
 423  */
 424 static int siw_tx_hdt(struct siw_iwarp_tx *c_tx, struct socket *s)
 425 {
 426         struct siw_wqe *wqe = &c_tx->wqe_active;
 427         struct siw_sge *sge = &wqe->sqe.sge[c_tx->sge_idx];
 428         struct kvec iov[MAX_ARRAY];
 429         struct page *page_array[MAX_ARRAY];
 430         struct msghdr msg = { .msg_flags = MSG_DONTWAIT | MSG_EOR };
 431 
 432         int seg = 0, do_crc = c_tx->do_crc, is_kva = 0, rv;
 433         unsigned int data_len = c_tx->bytes_unsent, hdr_len = 0, trl_len = 0,
 434                      sge_off = c_tx->sge_off, sge_idx = c_tx->sge_idx,
 435                      pbl_idx = c_tx->pbl_idx;
 436         unsigned long kmap_mask = 0L;
 437 
 438         if (c_tx->state == SIW_SEND_HDR) {
 439                 if (c_tx->use_sendpage) {
 440                         rv = siw_tx_ctrl(c_tx, s, MSG_DONTWAIT | MSG_MORE);
 441                         if (rv)
 442                                 goto done;
 443 
 444                         c_tx->state = SIW_SEND_DATA;
 445                 } else {
 446                         iov[0].iov_base =
 447                                 (char *)&c_tx->pkt.ctrl + c_tx->ctrl_sent;
 448                         iov[0].iov_len = hdr_len =
 449                                 c_tx->ctrl_len - c_tx->ctrl_sent;
 450                         seg = 1;
 451                 }
 452         }
 453 
 454         wqe->processed += data_len;
 455 
 456         while (data_len) { /* walk the list of SGE's */
 457                 unsigned int sge_len = min(sge->length - sge_off, data_len);
 458                 unsigned int fp_off = (sge->laddr + sge_off) & ~PAGE_MASK;
 459                 struct siw_mem *mem;
 460 
 461                 if (!(tx_flags(wqe) & SIW_WQE_INLINE)) {
 462                         mem = wqe->mem[sge_idx];
 463                         is_kva = mem->mem_obj == NULL ? 1 : 0;
 464                 } else {
 465                         is_kva = 1;
 466                 }
 467                 if (is_kva && !c_tx->use_sendpage) {
 468                         /*
 469                          * tx from kernel virtual address: either inline data
 470                          * or memory region with assigned kernel buffer
 471                          */
 472                         iov[seg].iov_base =
 473                                 (void *)(uintptr_t)(sge->laddr + sge_off);
 474                         iov[seg].iov_len = sge_len;
 475 
 476                         if (do_crc)
 477                                 crypto_shash_update(c_tx->mpa_crc_hd,
 478                                                     iov[seg].iov_base,
 479                                                     sge_len);
 480                         sge_off += sge_len;
 481                         data_len -= sge_len;
 482                         seg++;
 483                         goto sge_done;
 484                 }
 485 
 486                 while (sge_len) {
 487                         size_t plen = min((int)PAGE_SIZE - fp_off, sge_len);
 488 
 489                         if (!is_kva) {
 490                                 struct page *p;
 491 
 492                                 if (mem->is_pbl)
 493                                         p = siw_get_pblpage(
 494                                                 mem, sge->laddr + sge_off,
 495                                                 &pbl_idx);
 496                                 else
 497                                         p = siw_get_upage(mem->umem,
 498                                                           sge->laddr + sge_off);
 499                                 if (unlikely(!p)) {
 500                                         siw_unmap_pages(page_array, kmap_mask);
 501                                         wqe->processed -= c_tx->bytes_unsent;
 502                                         rv = -EFAULT;
 503                                         goto done_crc;
 504                                 }
 505                                 page_array[seg] = p;
 506 
 507                                 if (!c_tx->use_sendpage) {
 508                                         iov[seg].iov_base = kmap(p) + fp_off;
 509                                         iov[seg].iov_len = plen;
 510 
 511                                         /* Remember for later kunmap() */
 512                                         kmap_mask |= BIT(seg);
 513 
 514                                         if (do_crc)
 515                                                 crypto_shash_update(
 516                                                         c_tx->mpa_crc_hd,
 517                                                         iov[seg].iov_base,
 518                                                         plen);
 519                                 } else if (do_crc) {
 520                                         crypto_shash_update(c_tx->mpa_crc_hd,
 521                                                             kmap(p) + fp_off,
 522                                                             plen);
 523                                         kunmap(p);
 524                                 }
 525                         } else {
 526                                 u64 va = sge->laddr + sge_off;
 527 
 528                                 page_array[seg] = virt_to_page(va & PAGE_MASK);
 529                                 if (do_crc)
 530                                         crypto_shash_update(
 531                                                 c_tx->mpa_crc_hd,
 532                                                 (void *)(uintptr_t)va,
 533                                                 plen);
 534                         }
 535 
 536                         sge_len -= plen;
 537                         sge_off += plen;
 538                         data_len -= plen;
 539                         fp_off = 0;
 540 
 541                         if (++seg > (int)MAX_ARRAY) {
 542                                 siw_dbg_qp(tx_qp(c_tx), "to many fragments\n");
 543                                 siw_unmap_pages(page_array, kmap_mask);
 544                                 wqe->processed -= c_tx->bytes_unsent;
 545                                 rv = -EMSGSIZE;
 546                                 goto done_crc;
 547                         }
 548                 }
 549 sge_done:
 550                 /* Update SGE variables at end of SGE */
 551                 if (sge_off == sge->length &&
 552                     (data_len != 0 || wqe->processed < wqe->bytes)) {
 553                         sge_idx++;
 554                         sge++;
 555                         sge_off = 0;
 556                 }
 557         }
 558         /* trailer */
 559         if (likely(c_tx->state != SIW_SEND_TRAILER)) {
 560                 iov[seg].iov_base = &c_tx->trailer.pad[4 - c_tx->pad];
 561                 iov[seg].iov_len = trl_len = MAX_TRAILER - (4 - c_tx->pad);
 562         } else {
 563                 iov[seg].iov_base = &c_tx->trailer.pad[c_tx->ctrl_sent];
 564                 iov[seg].iov_len = trl_len = MAX_TRAILER - c_tx->ctrl_sent;
 565         }
 566 
 567         if (c_tx->pad) {
 568                 *(u32 *)c_tx->trailer.pad = 0;
 569                 if (do_crc)
 570                         crypto_shash_update(c_tx->mpa_crc_hd,
 571                                 (u8 *)&c_tx->trailer.crc - c_tx->pad,
 572                                 c_tx->pad);
 573         }
 574         if (!c_tx->mpa_crc_hd)
 575                 c_tx->trailer.crc = 0;
 576         else if (do_crc)
 577                 crypto_shash_final(c_tx->mpa_crc_hd, (u8 *)&c_tx->trailer.crc);
 578 
 579         data_len = c_tx->bytes_unsent;
 580 
 581         if (c_tx->use_sendpage) {
 582                 rv = siw_0copy_tx(s, page_array, &wqe->sqe.sge[c_tx->sge_idx],
 583                                   c_tx->sge_off, data_len);
 584                 if (rv == data_len) {
 585                         rv = kernel_sendmsg(s, &msg, &iov[seg], 1, trl_len);
 586                         if (rv > 0)
 587                                 rv += data_len;
 588                         else
 589                                 rv = data_len;
 590                 }
 591         } else {
 592                 rv = kernel_sendmsg(s, &msg, iov, seg + 1,
 593                                     hdr_len + data_len + trl_len);
 594                 siw_unmap_pages(page_array, kmap_mask);
 595         }
 596         if (rv < (int)hdr_len) {
 597                 /* Not even complete hdr pushed or negative rv */
 598                 wqe->processed -= data_len;
 599                 if (rv >= 0) {
 600                         c_tx->ctrl_sent += rv;
 601                         rv = -EAGAIN;
 602                 }
 603                 goto done_crc;
 604         }
 605         rv -= hdr_len;
 606 
 607         if (rv >= (int)data_len) {
 608                 /* all user data pushed to TCP or no data to push */
 609                 if (data_len > 0 && wqe->processed < wqe->bytes) {
 610                         /* Save the current state for next tx */
 611                         c_tx->sge_idx = sge_idx;
 612                         c_tx->sge_off = sge_off;
 613                         c_tx->pbl_idx = pbl_idx;
 614                 }
 615                 rv -= data_len;
 616 
 617                 if (rv == trl_len) /* all pushed */
 618                         rv = 0;
 619                 else {
 620                         c_tx->state = SIW_SEND_TRAILER;
 621                         c_tx->ctrl_len = MAX_TRAILER;
 622                         c_tx->ctrl_sent = rv + 4 - c_tx->pad;
 623                         c_tx->bytes_unsent = 0;
 624                         rv = -EAGAIN;
 625                 }
 626 
 627         } else if (data_len > 0) {
 628                 /* Maybe some user data pushed to TCP */
 629                 c_tx->state = SIW_SEND_DATA;
 630                 wqe->processed -= data_len - rv;
 631 
 632                 if (rv) {
 633                         /*
 634                          * Some bytes out. Recompute tx state based
 635                          * on old state and bytes pushed
 636                          */
 637                         unsigned int sge_unsent;
 638 
 639                         c_tx->bytes_unsent -= rv;
 640                         sge = &wqe->sqe.sge[c_tx->sge_idx];
 641                         sge_unsent = sge->length - c_tx->sge_off;
 642 
 643                         while (sge_unsent <= rv) {
 644                                 rv -= sge_unsent;
 645                                 c_tx->sge_idx++;
 646                                 c_tx->sge_off = 0;
 647                                 sge++;
 648                                 sge_unsent = sge->length;
 649                         }
 650                         c_tx->sge_off += rv;
 651                 }
 652                 rv = -EAGAIN;
 653         }
 654 done_crc:
 655         c_tx->do_crc = 0;
 656 done:
 657         return rv;
 658 }
 659 
 660 static void siw_update_tcpseg(struct siw_iwarp_tx *c_tx,
 661                                      struct socket *s)
 662 {
 663         struct tcp_sock *tp = tcp_sk(s->sk);
 664 
 665         if (tp->gso_segs) {
 666                 if (c_tx->gso_seg_limit == 0)
 667                         c_tx->tcp_seglen = tp->mss_cache * tp->gso_segs;
 668                 else
 669                         c_tx->tcp_seglen =
 670                                 tp->mss_cache *
 671                                 min_t(u16, c_tx->gso_seg_limit, tp->gso_segs);
 672         } else {
 673                 c_tx->tcp_seglen = tp->mss_cache;
 674         }
 675         /* Loopback may give odd numbers */
 676         c_tx->tcp_seglen &= 0xfffffff8;
 677 }
 678 
 679 /*
 680  * siw_prepare_fpdu()
 681  *
 682  * Prepares transmit context to send out one FPDU if FPDU will contain
 683  * user data and user data are not immediate data.
 684  * Computes maximum FPDU length to fill up TCP MSS if possible.
 685  *
 686  * @qp:         QP from which to transmit
 687  * @wqe:        Current WQE causing transmission
 688  *
 689  * TODO: Take into account real available sendspace on socket
 690  *       to avoid header misalignment due to send pausing within
 691  *       fpdu transmission
 692  */
 693 static void siw_prepare_fpdu(struct siw_qp *qp, struct siw_wqe *wqe)
 694 {
 695         struct siw_iwarp_tx *c_tx = &qp->tx_ctx;
 696         int data_len;
 697 
 698         c_tx->ctrl_len =
 699                 iwarp_pktinfo[__rdmap_get_opcode(&c_tx->pkt.ctrl)].hdr_len;
 700         c_tx->ctrl_sent = 0;
 701 
 702         /*
 703          * Update target buffer offset if any
 704          */
 705         if (!(c_tx->pkt.ctrl.ddp_rdmap_ctrl & DDP_FLAG_TAGGED))
 706                 /* Untagged message */
 707                 c_tx->pkt.c_untagged.ddp_mo = cpu_to_be32(wqe->processed);
 708         else /* Tagged message */
 709                 c_tx->pkt.c_tagged.ddp_to =
 710                         cpu_to_be64(wqe->sqe.raddr + wqe->processed);
 711 
 712         data_len = wqe->bytes - wqe->processed;
 713         if (data_len + c_tx->ctrl_len + MPA_CRC_SIZE > c_tx->tcp_seglen) {
 714                 /* Trim DDP payload to fit into current TCP segment */
 715                 data_len = c_tx->tcp_seglen - (c_tx->ctrl_len + MPA_CRC_SIZE);
 716                 c_tx->pkt.ctrl.ddp_rdmap_ctrl &= ~DDP_FLAG_LAST;
 717                 c_tx->pad = 0;
 718         } else {
 719                 c_tx->pkt.ctrl.ddp_rdmap_ctrl |= DDP_FLAG_LAST;
 720                 c_tx->pad = -data_len & 0x3;
 721         }
 722         c_tx->bytes_unsent = data_len;
 723 
 724         c_tx->pkt.ctrl.mpa_len =
 725                 htons(c_tx->ctrl_len + data_len - MPA_HDR_SIZE);
 726 
 727         /*
 728          * Init MPA CRC computation
 729          */
 730         if (c_tx->mpa_crc_hd) {
 731                 crypto_shash_init(c_tx->mpa_crc_hd);
 732                 crypto_shash_update(c_tx->mpa_crc_hd, (u8 *)&c_tx->pkt,
 733                                     c_tx->ctrl_len);
 734                 c_tx->do_crc = 1;
 735         }
 736 }
 737 
 738 /*
 739  * siw_check_sgl_tx()
 740  *
 741  * Check permissions for a list of SGE's (SGL).
 742  * A successful check will have all memory referenced
 743  * for transmission resolved and assigned to the WQE.
 744  *
 745  * @pd:         Protection Domain SGL should belong to
 746  * @wqe:        WQE to be checked
 747  * @perms:      requested access permissions
 748  *
 749  */
 750 
 751 static int siw_check_sgl_tx(struct ib_pd *pd, struct siw_wqe *wqe,
 752                             enum ib_access_flags perms)
 753 {
 754         struct siw_sge *sge = &wqe->sqe.sge[0];
 755         int i, len, num_sge = wqe->sqe.num_sge;
 756 
 757         if (unlikely(num_sge > SIW_MAX_SGE))
 758                 return -EINVAL;
 759 
 760         for (i = 0, len = 0; num_sge; num_sge--, i++, sge++) {
 761                 /*
 762                  * rdma verbs: do not check stag for a zero length sge
 763                  */
 764                 if (sge->length) {
 765                         int rv = siw_check_sge(pd, sge, &wqe->mem[i], perms, 0,
 766                                                sge->length);
 767 
 768                         if (unlikely(rv != E_ACCESS_OK))
 769                                 return rv;
 770                 }
 771                 len += sge->length;
 772         }
 773         return len;
 774 }
 775 
 776 /*
 777  * siw_qp_sq_proc_tx()
 778  *
 779  * Process one WQE which needs transmission on the wire.
 780  */
 781 static int siw_qp_sq_proc_tx(struct siw_qp *qp, struct siw_wqe *wqe)
 782 {
 783         struct siw_iwarp_tx *c_tx = &qp->tx_ctx;
 784         struct socket *s = qp->attrs.sk;
 785         int rv = 0, burst_len = qp->tx_ctx.burst;
 786         enum rdmap_ecode ecode = RDMAP_ECODE_CATASTROPHIC_STREAM;
 787 
 788         if (unlikely(wqe->wr_status == SIW_WR_IDLE))
 789                 return 0;
 790 
 791         if (!burst_len)
 792                 burst_len = SQ_USER_MAXBURST;
 793 
 794         if (wqe->wr_status == SIW_WR_QUEUED) {
 795                 if (!(wqe->sqe.flags & SIW_WQE_INLINE)) {
 796                         if (tx_type(wqe) == SIW_OP_READ_RESPONSE)
 797                                 wqe->sqe.num_sge = 1;
 798 
 799                         if (tx_type(wqe) != SIW_OP_READ &&
 800                             tx_type(wqe) != SIW_OP_READ_LOCAL_INV) {
 801                                 /*
 802                                  * Reference memory to be tx'd w/o checking
 803                                  * access for LOCAL_READ permission, since
 804                                  * not defined in RDMA core.
 805                                  */
 806                                 rv = siw_check_sgl_tx(qp->pd, wqe, 0);
 807                                 if (rv < 0) {
 808                                         if (tx_type(wqe) ==
 809                                             SIW_OP_READ_RESPONSE)
 810                                                 ecode = siw_rdmap_error(-rv);
 811                                         rv = -EINVAL;
 812                                         goto tx_error;
 813                                 }
 814                                 wqe->bytes = rv;
 815                         } else {
 816                                 wqe->bytes = 0;
 817                         }
 818                 } else {
 819                         wqe->bytes = wqe->sqe.sge[0].length;
 820                         if (!qp->kernel_verbs) {
 821                                 if (wqe->bytes > SIW_MAX_INLINE) {
 822                                         rv = -EINVAL;
 823                                         goto tx_error;
 824                                 }
 825                                 wqe->sqe.sge[0].laddr =
 826                                         (u64)(uintptr_t)&wqe->sqe.sge[1];
 827                         }
 828                 }
 829                 wqe->wr_status = SIW_WR_INPROGRESS;
 830                 wqe->processed = 0;
 831 
 832                 siw_update_tcpseg(c_tx, s);
 833 
 834                 rv = siw_qp_prepare_tx(c_tx);
 835                 if (rv == PKT_FRAGMENTED) {
 836                         c_tx->state = SIW_SEND_HDR;
 837                         siw_prepare_fpdu(qp, wqe);
 838                 } else if (rv == PKT_COMPLETE) {
 839                         c_tx->state = SIW_SEND_SHORT_FPDU;
 840                 } else {
 841                         goto tx_error;
 842                 }
 843         }
 844 
 845 next_segment:
 846         siw_dbg_qp(qp, "wr type %d, state %d, data %u, sent %u, id %llx\n",
 847                    tx_type(wqe), wqe->wr_status, wqe->bytes, wqe->processed,
 848                    wqe->sqe.id);
 849 
 850         if (--burst_len == 0) {
 851                 rv = -EINPROGRESS;
 852                 goto tx_done;
 853         }
 854         if (c_tx->state == SIW_SEND_SHORT_FPDU) {
 855                 enum siw_opcode tx_type = tx_type(wqe);
 856                 unsigned int msg_flags;
 857 
 858                 if (siw_sq_empty(qp) || !siw_tcp_nagle || burst_len == 1)
 859                         /*
 860                          * End current TCP segment, if SQ runs empty,
 861                          * or siw_tcp_nagle is not set, or we bail out
 862                          * soon due to no burst credit left.
 863                          */
 864                         msg_flags = MSG_DONTWAIT;
 865                 else
 866                         msg_flags = MSG_DONTWAIT | MSG_MORE;
 867 
 868                 rv = siw_tx_ctrl(c_tx, s, msg_flags);
 869 
 870                 if (!rv && tx_type != SIW_OP_READ &&
 871                     tx_type != SIW_OP_READ_LOCAL_INV)
 872                         wqe->processed = wqe->bytes;
 873 
 874                 goto tx_done;
 875 
 876         } else {
 877                 rv = siw_tx_hdt(c_tx, s);
 878         }
 879         if (!rv) {
 880                 /*
 881                  * One segment sent. Processing completed if last
 882                  * segment, Do next segment otherwise.
 883                  */
 884                 if (unlikely(c_tx->tx_suspend)) {
 885                         /*
 886                          * Verbs, 6.4.: Try stopping sending after a full
 887                          * DDP segment if the connection goes down
 888                          * (== peer halfclose)
 889                          */
 890                         rv = -ECONNABORTED;
 891                         goto tx_done;
 892                 }
 893                 if (c_tx->pkt.ctrl.ddp_rdmap_ctrl & DDP_FLAG_LAST) {
 894                         siw_dbg_qp(qp, "WQE completed\n");
 895                         goto tx_done;
 896                 }
 897                 c_tx->state = SIW_SEND_HDR;
 898 
 899                 siw_update_tcpseg(c_tx, s);
 900 
 901                 siw_prepare_fpdu(qp, wqe);
 902                 goto next_segment;
 903         }
 904 tx_done:
 905         qp->tx_ctx.burst = burst_len;
 906         return rv;
 907 
 908 tx_error:
 909         if (ecode != RDMAP_ECODE_CATASTROPHIC_STREAM)
 910                 siw_init_terminate(qp, TERM_ERROR_LAYER_RDMAP,
 911                                    RDMAP_ETYPE_REMOTE_PROTECTION, ecode, 1);
 912         else
 913                 siw_init_terminate(qp, TERM_ERROR_LAYER_RDMAP,
 914                                    RDMAP_ETYPE_CATASTROPHIC,
 915                                    RDMAP_ECODE_UNSPECIFIED, 1);
 916         return rv;
 917 }
 918 
 919 static int siw_fastreg_mr(struct ib_pd *pd, struct siw_sqe *sqe)
 920 {
 921         struct ib_mr *base_mr = (struct ib_mr *)(uintptr_t)sqe->base_mr;
 922         struct siw_device *sdev = to_siw_dev(pd->device);
 923         struct siw_mem *mem;
 924         int rv = 0;
 925 
 926         siw_dbg_pd(pd, "STag 0x%08x\n", sqe->rkey);
 927 
 928         if (unlikely(!base_mr)) {
 929                 pr_warn("siw: fastreg: STag 0x%08x unknown\n", sqe->rkey);
 930                 return -EINVAL;
 931         }
 932 
 933         if (unlikely(base_mr->rkey >> 8 != sqe->rkey  >> 8)) {
 934                 pr_warn("siw: fastreg: STag 0x%08x: bad MR\n", sqe->rkey);
 935                 return -EINVAL;
 936         }
 937 
 938         mem = siw_mem_id2obj(sdev, sqe->rkey  >> 8);
 939         if (unlikely(!mem)) {
 940                 pr_warn("siw: fastreg: STag 0x%08x unknown\n", sqe->rkey);
 941                 return -EINVAL;
 942         }
 943 
 944         if (unlikely(mem->pd != pd)) {
 945                 pr_warn("siw: fastreg: PD mismatch\n");
 946                 rv = -EINVAL;
 947                 goto out;
 948         }
 949         if (unlikely(mem->stag_valid)) {
 950                 pr_warn("siw: fastreg: STag 0x%08x already valid\n", sqe->rkey);
 951                 rv = -EINVAL;
 952                 goto out;
 953         }
 954         /* Refresh STag since user may have changed key part */
 955         mem->stag = sqe->rkey;
 956         mem->perms = sqe->access;
 957 
 958         siw_dbg_mem(mem, "STag 0x%08x now valid\n", sqe->rkey);
 959         mem->va = base_mr->iova;
 960         mem->stag_valid = 1;
 961 out:
 962         siw_mem_put(mem);
 963         return rv;
 964 }
 965 
 966 static int siw_qp_sq_proc_local(struct siw_qp *qp, struct siw_wqe *wqe)
 967 {
 968         int rv;
 969 
 970         switch (tx_type(wqe)) {
 971         case SIW_OP_REG_MR:
 972                 rv = siw_fastreg_mr(qp->pd, &wqe->sqe);
 973                 break;
 974 
 975         case SIW_OP_INVAL_STAG:
 976                 rv = siw_invalidate_stag(qp->pd, wqe->sqe.rkey);
 977                 break;
 978 
 979         default:
 980                 rv = -EINVAL;
 981         }
 982         return rv;
 983 }
 984 
 985 /*
 986  * siw_qp_sq_process()
 987  *
 988  * Core TX path routine for RDMAP/DDP/MPA using a TCP kernel socket.
 989  * Sends RDMAP payload for the current SQ WR @wqe of @qp in one or more
 990  * MPA FPDUs, each containing a DDP segment.
 991  *
 992  * SQ processing may occur in user context as a result of posting
 993  * new WQE's or from siw_sq_work_handler() context. Processing in
 994  * user context is limited to non-kernel verbs users.
 995  *
 996  * SQ processing may get paused anytime, possibly in the middle of a WR
 997  * or FPDU, if insufficient send space is available. SQ processing
 998  * gets resumed from siw_sq_work_handler(), if send space becomes
 999  * available again.
1000  *
1001  * Must be called with the QP state read-locked.
1002  *
1003  * Note:
1004  * An outbound RREQ can be satisfied by the corresponding RRESP
1005  * _before_ it gets assigned to the ORQ. This happens regularly
1006  * in RDMA READ via loopback case. Since both outbound RREQ and
1007  * inbound RRESP can be handled by the same CPU, locking the ORQ
1008  * is dead-lock prone and thus not an option. With that, the
1009  * RREQ gets assigned to the ORQ _before_ being sent - see
1010  * siw_activate_tx() - and pulled back in case of send failure.
1011  */
1012 int siw_qp_sq_process(struct siw_qp *qp)
1013 {
1014         struct siw_wqe *wqe = tx_wqe(qp);
1015         enum siw_opcode tx_type;
1016         unsigned long flags;
1017         int rv = 0;
1018 
1019         siw_dbg_qp(qp, "enter for type %d\n", tx_type(wqe));
1020 
1021 next_wqe:
1022         /*
1023          * Stop QP processing if SQ state changed
1024          */
1025         if (unlikely(qp->tx_ctx.tx_suspend)) {
1026                 siw_dbg_qp(qp, "tx suspended\n");
1027                 goto done;
1028         }
1029         tx_type = tx_type(wqe);
1030 
1031         if (tx_type <= SIW_OP_READ_RESPONSE)
1032                 rv = siw_qp_sq_proc_tx(qp, wqe);
1033         else
1034                 rv = siw_qp_sq_proc_local(qp, wqe);
1035 
1036         if (!rv) {
1037                 /*
1038                  * WQE processing done
1039                  */
1040                 switch (tx_type) {
1041                 case SIW_OP_SEND:
1042                 case SIW_OP_SEND_REMOTE_INV:
1043                 case SIW_OP_WRITE:
1044                         siw_wqe_put_mem(wqe, tx_type);
1045                         /* Fall through */
1046 
1047                 case SIW_OP_INVAL_STAG:
1048                 case SIW_OP_REG_MR:
1049                         if (tx_flags(wqe) & SIW_WQE_SIGNALLED)
1050                                 siw_sqe_complete(qp, &wqe->sqe, wqe->bytes,
1051                                                  SIW_WC_SUCCESS);
1052                         break;
1053 
1054                 case SIW_OP_READ:
1055                 case SIW_OP_READ_LOCAL_INV:
1056                         /*
1057                          * already enqueued to ORQ queue
1058                          */
1059                         break;
1060 
1061                 case SIW_OP_READ_RESPONSE:
1062                         siw_wqe_put_mem(wqe, tx_type);
1063                         break;
1064 
1065                 default:
1066                         WARN(1, "undefined WQE type %d\n", tx_type);
1067                         rv = -EINVAL;
1068                         goto done;
1069                 }
1070 
1071                 spin_lock_irqsave(&qp->sq_lock, flags);
1072                 wqe->wr_status = SIW_WR_IDLE;
1073                 rv = siw_activate_tx(qp);
1074                 spin_unlock_irqrestore(&qp->sq_lock, flags);
1075 
1076                 if (rv <= 0)
1077                         goto done;
1078 
1079                 goto next_wqe;
1080 
1081         } else if (rv == -EAGAIN) {
1082                 siw_dbg_qp(qp, "sq paused: hd/tr %d of %d, data %d\n",
1083                            qp->tx_ctx.ctrl_sent, qp->tx_ctx.ctrl_len,
1084                            qp->tx_ctx.bytes_unsent);
1085                 rv = 0;
1086                 goto done;
1087         } else if (rv == -EINPROGRESS) {
1088                 rv = siw_sq_start(qp);
1089                 goto done;
1090         } else {
1091                 /*
1092                  * WQE processing failed.
1093                  * Verbs 8.3.2:
1094                  * o It turns any WQE into a signalled WQE.
1095                  * o Local catastrophic error must be surfaced
1096                  * o QP must be moved into Terminate state: done by code
1097                  *   doing socket state change processing
1098                  *
1099                  * o TODO: Termination message must be sent.
1100                  * o TODO: Implement more precise work completion errors,
1101                  *         see enum ib_wc_status in ib_verbs.h
1102                  */
1103                 siw_dbg_qp(qp, "wqe type %d processing failed: %d\n",
1104                            tx_type(wqe), rv);
1105 
1106                 spin_lock_irqsave(&qp->sq_lock, flags);
1107                 /*
1108                  * RREQ may have already been completed by inbound RRESP!
1109                  */
1110                 if (tx_type == SIW_OP_READ ||
1111                     tx_type == SIW_OP_READ_LOCAL_INV) {
1112                         /* Cleanup pending entry in ORQ */
1113                         qp->orq_put--;
1114                         qp->orq[qp->orq_put % qp->attrs.orq_size].flags = 0;
1115                 }
1116                 spin_unlock_irqrestore(&qp->sq_lock, flags);
1117                 /*
1118                  * immediately suspends further TX processing
1119                  */
1120                 if (!qp->tx_ctx.tx_suspend)
1121                         siw_qp_cm_drop(qp, 0);
1122 
1123                 switch (tx_type) {
1124                 case SIW_OP_SEND:
1125                 case SIW_OP_SEND_REMOTE_INV:
1126                 case SIW_OP_SEND_WITH_IMM:
1127                 case SIW_OP_WRITE:
1128                 case SIW_OP_READ:
1129                 case SIW_OP_READ_LOCAL_INV:
1130                         siw_wqe_put_mem(wqe, tx_type);
1131                         /* Fall through */
1132 
1133                 case SIW_OP_INVAL_STAG:
1134                 case SIW_OP_REG_MR:
1135                         siw_sqe_complete(qp, &wqe->sqe, wqe->bytes,
1136                                          SIW_WC_LOC_QP_OP_ERR);
1137 
1138                         siw_qp_event(qp, IB_EVENT_QP_FATAL);
1139 
1140                         break;
1141 
1142                 case SIW_OP_READ_RESPONSE:
1143                         siw_dbg_qp(qp, "proc. read.response failed: %d\n", rv);
1144 
1145                         siw_qp_event(qp, IB_EVENT_QP_REQ_ERR);
1146 
1147                         siw_wqe_put_mem(wqe, SIW_OP_READ_RESPONSE);
1148 
1149                         break;
1150 
1151                 default:
1152                         WARN(1, "undefined WQE type %d\n", tx_type);
1153                         rv = -EINVAL;
1154                 }
1155                 wqe->wr_status = SIW_WR_IDLE;
1156         }
1157 done:
1158         return rv;
1159 }
1160 
1161 static void siw_sq_resume(struct siw_qp *qp)
1162 {
1163         if (down_read_trylock(&qp->state_lock)) {
1164                 if (likely(qp->attrs.state == SIW_QP_STATE_RTS &&
1165                            !qp->tx_ctx.tx_suspend)) {
1166                         int rv = siw_qp_sq_process(qp);
1167 
1168                         up_read(&qp->state_lock);
1169 
1170                         if (unlikely(rv < 0)) {
1171                                 siw_dbg_qp(qp, "SQ task failed: err %d\n", rv);
1172 
1173                                 if (!qp->tx_ctx.tx_suspend)
1174                                         siw_qp_cm_drop(qp, 0);
1175                         }
1176                 } else {
1177                         up_read(&qp->state_lock);
1178                 }
1179         } else {
1180                 siw_dbg_qp(qp, "Resume SQ while QP locked\n");
1181         }
1182         siw_qp_put(qp);
1183 }
1184 
1185 struct tx_task_t {
1186         struct llist_head active;
1187         wait_queue_head_t waiting;
1188 };
1189 
1190 static DEFINE_PER_CPU(struct tx_task_t, siw_tx_task_g);
1191 
1192 void siw_stop_tx_thread(int nr_cpu)
1193 {
1194         kthread_stop(siw_tx_thread[nr_cpu]);
1195         wake_up(&per_cpu(siw_tx_task_g, nr_cpu).waiting);
1196 }
1197 
1198 int siw_run_sq(void *data)
1199 {
1200         const int nr_cpu = (unsigned int)(long)data;
1201         struct llist_node *active;
1202         struct siw_qp *qp;
1203         struct tx_task_t *tx_task = &per_cpu(siw_tx_task_g, nr_cpu);
1204 
1205         init_llist_head(&tx_task->active);
1206         init_waitqueue_head(&tx_task->waiting);
1207 
1208         while (1) {
1209                 struct llist_node *fifo_list = NULL;
1210 
1211                 wait_event_interruptible(tx_task->waiting,
1212                                          !llist_empty(&tx_task->active) ||
1213                                                  kthread_should_stop());
1214 
1215                 if (kthread_should_stop())
1216                         break;
1217 
1218                 active = llist_del_all(&tx_task->active);
1219                 /*
1220                  * llist_del_all returns a list with newest entry first.
1221                  * Re-order list for fairness among QP's.
1222                  */
1223                 while (active) {
1224                         struct llist_node *tmp = active;
1225 
1226                         active = llist_next(active);
1227                         tmp->next = fifo_list;
1228                         fifo_list = tmp;
1229                 }
1230                 while (fifo_list) {
1231                         qp = container_of(fifo_list, struct siw_qp, tx_list);
1232                         fifo_list = llist_next(fifo_list);
1233                         qp->tx_list.next = NULL;
1234 
1235                         siw_sq_resume(qp);
1236                 }
1237         }
1238         active = llist_del_all(&tx_task->active);
1239         if (active) {
1240                 llist_for_each_entry(qp, active, tx_list) {
1241                         qp->tx_list.next = NULL;
1242                         siw_sq_resume(qp);
1243                 }
1244         }
1245         return 0;
1246 }
1247 
1248 int siw_sq_start(struct siw_qp *qp)
1249 {
1250         if (tx_wqe(qp)->wr_status == SIW_WR_IDLE)
1251                 return 0;
1252 
1253         if (unlikely(!cpu_online(qp->tx_cpu))) {
1254                 siw_put_tx_cpu(qp->tx_cpu);
1255                 qp->tx_cpu = siw_get_tx_cpu(qp->sdev);
1256                 if (qp->tx_cpu < 0) {
1257                         pr_warn("siw: no tx cpu available\n");
1258 
1259                         return -EIO;
1260                 }
1261         }
1262         siw_qp_get(qp);
1263 
1264         llist_add(&qp->tx_list, &per_cpu(siw_tx_task_g, qp->tx_cpu).active);
1265 
1266         wake_up(&per_cpu(siw_tx_task_g, qp->tx_cpu).waiting);
1267 
1268         return 0;
1269 }
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root/drivers/infiniband/sw/siw/siw_qp_tx.c

DEFINITIONS
