drivers/staging/octeon/cvmx-cmd-queue.h

   1 /***********************license start***************
   2  * Author: Cavium Networks
   3  *
   4  * Contact: support@caviumnetworks.com
   5  * This file is part of the OCTEON SDK
   6  *
   7  * Copyright (c) 2003-2008 Cavium Networks
   8  *
   9  * This file is free software; you can redistribute it and/or modify
  10  * it under the terms of the GNU General Public License, Version 2, as
  11  * published by the Free Software Foundation.
  12  *
  13  * This file is distributed in the hope that it will be useful, but
  14  * AS-IS and WITHOUT ANY WARRANTY; without even the implied warranty
  15  * of MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE, TITLE, or
  16  * NONINFRINGEMENT.  See the GNU General Public License for more
  17  * details.
  18  *
  19  * You should have received a copy of the GNU General Public License
  20  * along with this file; if not, write to the Free Software
  21  * Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA
  22  * or visit http://www.gnu.org/licenses/.
  23  *
  24  * This file may also be available under a different license from Cavium.
  25  * Contact Cavium Networks for more information
  26  ***********************license end**************************************/
  27
  28 /*
  29  *
  30  * Support functions for managing command queues used for
  31  * various hardware blocks.
  32  *
  33  * The common command queue infrastructure abstracts out the
  34  * software necessary for adding to Octeon's chained queue
  35  * structures. These structures are used for commands to the
  36  * PKO, ZIP, DFA, RAID, and DMA engine blocks. Although each
  37  * hardware unit takes commands and CSRs of different types,
  38  * they all use basic linked command buffers to store the
  39  * pending request. In general, users of the CVMX API don't
  40  * call cvmx-cmd-queue functions directly. Instead the hardware
  41  * unit specific wrapper should be used. The wrappers perform
  42  * unit specific validation and CSR writes to submit the
  43  * commands.
  44  *
  45  * Even though most software will never directly interact with
  46  * cvmx-cmd-queue, knowledge of its internal working can help
  47  * in diagnosing performance problems and help with debugging.
  48  *
  49  * Command queue pointers are stored in a global named block
  50  * called "cvmx_cmd_queues". Except for the PKO queues, each
  51  * hardware queue is stored in its own cache line to reduce SMP
  52  * contention on spin locks. The PKO queues are stored such that
  53  * every 16th queue is next to each other in memory. This scheme
  54  * allows for queues being in separate cache lines when there
  55  * are low number of queues per port. With 16 queues per port,
  56  * the first queue for each port is in the same cache area. The
  57  * second queues for each port are in another area, etc. This
  58  * allows software to implement very efficient lockless PKO with
  59  * 16 queues per port using a minimum of cache lines per core.
  60  * All queues for a given core will be isolated in the same
  61  * cache area.
  62  *
  63  * In addition to the memory pointer layout, cvmx-cmd-queue
  64  * provides an optimized fair ll/sc locking mechanism for the
  65  * queues. The lock uses a "ticket / now serving" model to
  66  * maintain fair order on contended locks. In addition, it uses
  67  * predicted locking time to limit cache contention. When a core
  68  * know it must wait in line for a lock, it spins on the
  69  * internal cycle counter to completely eliminate any causes of
  70  * bus traffic.
  71  *
  72  */
  73
  74 #ifndef __CVMX_CMD_QUEUE_H__
  75 #define __CVMX_CMD_QUEUE_H__
  76
  77 #include <linux/prefetch.h>
  78
  79 #include "cvmx-fpa.h"
  80 /**
  81  * By default we disable the max depth support. Most programs
  82  * don't use it and it slows down the command queue processing
  83  * significantly.
  84  */
  85 #ifndef CVMX_CMD_QUEUE_ENABLE_MAX_DEPTH
  86 #define CVMX_CMD_QUEUE_ENABLE_MAX_DEPTH 0
  87 #endif
  88
  89 /**
  90  * Enumeration representing all hardware blocks that use command
  91  * queues. Each hardware block has up to 65536 sub identifiers for
  92  * multiple command queues. Not all chips support all hardware
  93  * units.
  94  */
  95 typedef enum {
  96         CVMX_CMD_QUEUE_PKO_BASE = 0x00000,
  97
  98 #define CVMX_CMD_QUEUE_PKO(queue) \
  99         ((cvmx_cmd_queue_id_t)(CVMX_CMD_QUEUE_PKO_BASE + (0xffff&(queue))))
 100
 101         CVMX_CMD_QUEUE_ZIP = 0x10000,
 102         CVMX_CMD_QUEUE_DFA = 0x20000,
 103         CVMX_CMD_QUEUE_RAID = 0x30000,
 104         CVMX_CMD_QUEUE_DMA_BASE = 0x40000,
 105
 106 #define CVMX_CMD_QUEUE_DMA(queue) \
 107         ((cvmx_cmd_queue_id_t)(CVMX_CMD_QUEUE_DMA_BASE + (0xffff&(queue))))
 108
 109         CVMX_CMD_QUEUE_END = 0x50000,
 110 } cvmx_cmd_queue_id_t;
 111
 112 /**
 113  * Command write operations can fail if the command queue needs
 114  * a new buffer and the associated FPA pool is empty. It can also
 115  * fail if the number of queued command words reaches the maximum
 116  * set at initialization.
 117  */
 118 typedef enum {
 119         CVMX_CMD_QUEUE_SUCCESS = 0,
 120         CVMX_CMD_QUEUE_NO_MEMORY = -1,
 121         CVMX_CMD_QUEUE_FULL = -2,
 122         CVMX_CMD_QUEUE_INVALID_PARAM = -3,
 123         CVMX_CMD_QUEUE_ALREADY_SETUP = -4,
 124 } cvmx_cmd_queue_result_t;
 125
 126 typedef struct {
 127         /* You have lock when this is your ticket */
 128         uint8_t now_serving;
 129         uint64_t unused1:24;
 130         /* Maximum outstanding command words */
 131         uint32_t max_depth;
 132         /* FPA pool buffers come from */
 133         uint64_t fpa_pool:3;
 134         /* Top of command buffer pointer shifted 7 */
 135         uint64_t base_ptr_div128:29;
 136         uint64_t unused2:6;
 137         /* FPA buffer size in 64bit words minus 1 */
 138         uint64_t pool_size_m1:13;
 139         /* Number of commands already used in buffer */
 140         uint64_t index:13;
 141 } __cvmx_cmd_queue_state_t;
 142
 143 /**
 144  * This structure contains the global state of all command queues.
 145  * It is stored in a bootmem named block and shared by all
 146  * applications running on Octeon. Tickets are stored in a differnet
 147  * cahce line that queue information to reduce the contention on the
 148  * ll/sc used to get a ticket. If this is not the case, the update
 149  * of queue state causes the ll/sc to fail quite often.
 150  */
 151 typedef struct {
 152         uint64_t ticket[(CVMX_CMD_QUEUE_END >> 16) * 256];
 153         __cvmx_cmd_queue_state_t state[(CVMX_CMD_QUEUE_END >> 16) * 256];
 154 } __cvmx_cmd_queue_all_state_t;
 155
 156 /**
 157  * Initialize a command queue for use. The initial FPA buffer is
 158  * allocated and the hardware unit is configured to point to the
 159  * new command queue.
 160  *
 161  * @queue_id:  Hardware command queue to initialize.
 162  * @max_depth: Maximum outstanding commands that can be queued.
 163  * @fpa_pool:  FPA pool the command queues should come from.
 164  * @pool_size: Size of each buffer in the FPA pool (bytes)
 165  *
 166  * Returns CVMX_CMD_QUEUE_SUCCESS or a failure code
 167  */
 168 cvmx_cmd_queue_result_t cvmx_cmd_queue_initialize(cvmx_cmd_queue_id_t queue_id,
 169                                                   int max_depth, int fpa_pool,
 170                                                   int pool_size);
 171
 172 /**
 173  * Shutdown a queue a free it's command buffers to the FPA. The
 174  * hardware connected to the queue must be stopped before this
 175  * function is called.
 176  *
 177  * @queue_id: Queue to shutdown
 178  *
 179  * Returns CVMX_CMD_QUEUE_SUCCESS or a failure code
 180  */
 181 cvmx_cmd_queue_result_t cvmx_cmd_queue_shutdown(cvmx_cmd_queue_id_t queue_id);
 182
 183 /**
 184  * Return the number of command words pending in the queue. This
 185  * function may be relatively slow for some hardware units.
 186  *
 187  * @queue_id: Hardware command queue to query
 188  *
 189  * Returns Number of outstanding commands
 190  */
 191 int cvmx_cmd_queue_length(cvmx_cmd_queue_id_t queue_id);
 192
 193 /**
 194  * Return the command buffer to be written to. The purpose of this
 195  * function is to allow CVMX routine access t othe low level buffer
 196  * for initial hardware setup. User applications should not call this
 197  * function directly.
 198  *
 199  * @queue_id: Command queue to query
 200  *
 201  * Returns Command buffer or NULL on failure
 202  */
 203 void *cvmx_cmd_queue_buffer(cvmx_cmd_queue_id_t queue_id);
 204
 205 /**
 206  * Get the index into the state arrays for the supplied queue id.
 207  *
 208  * @queue_id: Queue ID to get an index for
 209  *
 210  * Returns Index into the state arrays
 211  */
 212 static inline int __cvmx_cmd_queue_get_index(cvmx_cmd_queue_id_t queue_id)
 213 {
 214         /*
 215          * Warning: This code currently only works with devices that
 216          * have 256 queues or less. Devices with more than 16 queues
 217          * are laid out in memory to allow cores quick access to
 218          * every 16th queue. This reduces cache thrashing when you are
 219          * running 16 queues per port to support lockless operation.
 220          */
 221         int unit = queue_id >> 16;
 222         int q = (queue_id >> 4) & 0xf;
 223         int core = queue_id & 0xf;
 224         return unit * 256 + core * 16 + q;
 225 }
 226
 227 /**
 228  * Lock the supplied queue so nobody else is updating it at the same
 229  * time as us.
 230  *
 231  * @queue_id: Queue ID to lock
 232  * @qptr:     Pointer to the queue's global state
 233  */
 234 static inline void __cvmx_cmd_queue_lock(cvmx_cmd_queue_id_t queue_id,
 235                                          __cvmx_cmd_queue_state_t *qptr)
 236 {
 237         extern __cvmx_cmd_queue_all_state_t
 238             *__cvmx_cmd_queue_state_ptr;
 239         int tmp;
 240         int my_ticket;
 241         prefetch(qptr);
 242         asm volatile (
 243                 ".set push\n"
 244                 ".set noreorder\n"
 245                 "1:\n"
 246                 /* Atomic add one to ticket_ptr */
 247                 "ll     %[my_ticket], %[ticket_ptr]\n"
 248                 /* and store the original value */
 249                 "li     %[ticket], 1\n"
 250                 /* in my_ticket */
 251                 "baddu  %[ticket], %[my_ticket]\n"
 252                 "sc     %[ticket], %[ticket_ptr]\n"
 253                 "beqz   %[ticket], 1b\n"
 254                 " nop\n"
 255                 /* Load the current now_serving ticket */
 256                 "lbu    %[ticket], %[now_serving]\n"
 257                 "2:\n"
 258                 /* Jump out if now_serving == my_ticket */
 259                 "beq    %[ticket], %[my_ticket], 4f\n"
 260                 /* Find out how many tickets are in front of me */
 261                 " subu   %[ticket], %[my_ticket], %[ticket]\n"
 262                 /* Use tickets in front of me minus one to delay */
 263                 "subu  %[ticket], 1\n"
 264                 /* Delay will be ((tickets in front)-1)*32 loops */
 265                 "cins   %[ticket], %[ticket], 5, 7\n"
 266                 "3:\n"
 267                 /* Loop here until our ticket might be up */
 268                 "bnez   %[ticket], 3b\n"
 269                 " subu  %[ticket], 1\n"
 270                 /* Jump back up to check out ticket again */
 271                 "b      2b\n"
 272                 /* Load the current now_serving ticket */
 273                 " lbu   %[ticket], %[now_serving]\n"
 274                 "4:\n"
 275                 ".set pop\n" :
 276                 [ticket_ptr] "=m"(__cvmx_cmd_queue_state_ptr->ticket[__cvmx_cmd_queue_get_index(queue_id)]),
 277                 [now_serving] "=m"(qptr->now_serving), [ticket] "=r"(tmp),
 278                 [my_ticket] "=r"(my_ticket)
 279             );
 280 }
 281
 282 /**
 283  * Unlock the queue, flushing all writes.
 284  *
 285  * @qptr:   Queue to unlock
 286  */
 287 static inline void __cvmx_cmd_queue_unlock(__cvmx_cmd_queue_state_t *qptr)
 288 {
 289         qptr->now_serving++;
 290         CVMX_SYNCWS;
 291 }
 292
 293 /**
 294  * Get the queue state structure for the given queue id
 295  *
 296  * @queue_id: Queue id to get
 297  *
 298  * Returns Queue structure or NULL on failure
 299  */
 300 static inline __cvmx_cmd_queue_state_t
 301     *__cvmx_cmd_queue_get_state(cvmx_cmd_queue_id_t queue_id)
 302 {
 303         extern __cvmx_cmd_queue_all_state_t
 304             *__cvmx_cmd_queue_state_ptr;
 305         return &__cvmx_cmd_queue_state_ptr->
 306             state[__cvmx_cmd_queue_get_index(queue_id)];
 307 }
 308
 309 /**
 310  * Write an arbitrary number of command words to a command queue.
 311  * This is a generic function; the fixed number of command word
 312  * functions yield higher performance.
 313  *
 314  * @queue_id:  Hardware command queue to write to
 315  * @use_locking:
 316  *                  Use internal locking to ensure exclusive access for queue
 317  *                  updates. If you don't use this locking you must ensure
 318  *                  exclusivity some other way. Locking is strongly recommended.
 319  * @cmd_count: Number of command words to write
 320  * @cmds:      Array of commands to write
 321  *
 322  * Returns CVMX_CMD_QUEUE_SUCCESS or a failure code
 323  */
 324 static inline cvmx_cmd_queue_result_t cvmx_cmd_queue_write(cvmx_cmd_queue_id_t
 325                                                            queue_id,
 326                                                            int use_locking,
 327                                                            int cmd_count,
 328                                                            uint64_t *cmds)
 329 {
 330         __cvmx_cmd_queue_state_t *qptr = __cvmx_cmd_queue_get_state(queue_id);
 331
 332         /* Make sure nobody else is updating the same queue */
 333         if (likely(use_locking))
 334                 __cvmx_cmd_queue_lock(queue_id, qptr);
 335
 336         /*
 337          * If a max queue length was specified then make sure we don't
 338          * exceed it. If any part of the command would be below the
 339          * limit we allow it.
 340          */
 341         if (CVMX_CMD_QUEUE_ENABLE_MAX_DEPTH && unlikely(qptr->max_depth)) {
 342                 if (unlikely
 343                     (cvmx_cmd_queue_length(queue_id) > (int)qptr->max_depth)) {
 344                         if (likely(use_locking))
 345                                 __cvmx_cmd_queue_unlock(qptr);
 346                         return CVMX_CMD_QUEUE_FULL;
 347                 }
 348         }
 349
 350         /*
 351          * Normally there is plenty of room in the current buffer for
 352          * the command.
 353          */
 354         if (likely(qptr->index + cmd_count < qptr->pool_size_m1)) {
 355                 uint64_t *ptr =
 356                     (uint64_t *) cvmx_phys_to_ptr((uint64_t) qptr->
 357                                                   base_ptr_div128 << 7);
 358                 ptr += qptr->index;
 359                 qptr->index += cmd_count;
 360                 while (cmd_count--)
 361                         *ptr++ = *cmds++;
 362         } else {
 363                 uint64_t *ptr;
 364                 int count;
 365                 /*
 366                  * We need a new command buffer. Fail if there isn't
 367                  * one available.
 368                  */
 369                 uint64_t *new_buffer =
 370                     (uint64_t *) cvmx_fpa_alloc(qptr->fpa_pool);
 371                 if (unlikely(new_buffer == NULL)) {
 372                         if (likely(use_locking))
 373                                 __cvmx_cmd_queue_unlock(qptr);
 374                         return CVMX_CMD_QUEUE_NO_MEMORY;
 375                 }
 376                 ptr =
 377                     (uint64_t *) cvmx_phys_to_ptr((uint64_t) qptr->
 378                                                   base_ptr_div128 << 7);
 379                 /*
 380                  * Figure out how many command words will fit in this
 381                  * buffer. One location will be needed for the next
 382                  * buffer pointer.
 383                  */
 384                 count = qptr->pool_size_m1 - qptr->index;
 385                 ptr += qptr->index;
 386                 cmd_count -= count;
 387                 while (count--)
 388                         *ptr++ = *cmds++;
 389                 *ptr = cvmx_ptr_to_phys(new_buffer);
 390                 /*
 391                  * The current buffer is full and has a link to the
 392                  * next buffer. Time to write the rest of the commands
 393                  * into the new buffer.
 394                  */
 395                 qptr->base_ptr_div128 = *ptr >> 7;
 396                 qptr->index = cmd_count;
 397                 ptr = new_buffer;
 398                 while (cmd_count--)
 399                         *ptr++ = *cmds++;
 400         }
 401
 402         /* All updates are complete. Release the lock and return */
 403         if (likely(use_locking))
 404                 __cvmx_cmd_queue_unlock(qptr);
 405         return CVMX_CMD_QUEUE_SUCCESS;
 406 }
 407
 408 /**
 409  * Simple function to write two command words to a command
 410  * queue.
 411  *
 412  * @queue_id: Hardware command queue to write to
 413  * @use_locking:
 414  *                 Use internal locking to ensure exclusive access for queue
 415  *                 updates. If you don't use this locking you must ensure
 416  *                 exclusivity some other way. Locking is strongly recommended.
 417  * @cmd1:     Command
 418  * @cmd2:     Command
 419  *
 420  * Returns CVMX_CMD_QUEUE_SUCCESS or a failure code
 421  */
 422 static inline cvmx_cmd_queue_result_t cvmx_cmd_queue_write2(cvmx_cmd_queue_id_t
 423                                                             queue_id,
 424                                                             int use_locking,
 425                                                             uint64_t cmd1,
 426                                                             uint64_t cmd2)
 427 {
 428         __cvmx_cmd_queue_state_t *qptr = __cvmx_cmd_queue_get_state(queue_id);
 429
 430         /* Make sure nobody else is updating the same queue */
 431         if (likely(use_locking))
 432                 __cvmx_cmd_queue_lock(queue_id, qptr);
 433
 434         /*
 435          * If a max queue length was specified then make sure we don't
 436          * exceed it. If any part of the command would be below the
 437          * limit we allow it.
 438          */
 439         if (CVMX_CMD_QUEUE_ENABLE_MAX_DEPTH && unlikely(qptr->max_depth)) {
 440                 if (unlikely
 441                     (cvmx_cmd_queue_length(queue_id) > (int)qptr->max_depth)) {
 442                         if (likely(use_locking))
 443                                 __cvmx_cmd_queue_unlock(qptr);
 444                         return CVMX_CMD_QUEUE_FULL;
 445                 }
 446         }
 447
 448         /*
 449          * Normally there is plenty of room in the current buffer for
 450          * the command.
 451          */
 452         if (likely(qptr->index + 2 < qptr->pool_size_m1)) {
 453                 uint64_t *ptr =
 454                     (uint64_t *) cvmx_phys_to_ptr((uint64_t) qptr->
 455                                                   base_ptr_div128 << 7);
 456                 ptr += qptr->index;
 457                 qptr->index += 2;
 458                 ptr[0] = cmd1;
 459                 ptr[1] = cmd2;
 460         } else {
 461                 uint64_t *ptr;
 462                 /*
 463                  * Figure out how many command words will fit in this
 464                  * buffer. One location will be needed for the next
 465                  * buffer pointer.
 466                  */
 467                 int count = qptr->pool_size_m1 - qptr->index;
 468                 /*
 469                  * We need a new command buffer. Fail if there isn't
 470                  * one available.
 471                  */
 472                 uint64_t *new_buffer =
 473                     (uint64_t *) cvmx_fpa_alloc(qptr->fpa_pool);
 474                 if (unlikely(new_buffer == NULL)) {
 475                         if (likely(use_locking))
 476                                 __cvmx_cmd_queue_unlock(qptr);
 477                         return CVMX_CMD_QUEUE_NO_MEMORY;
 478                 }
 479                 count--;
 480                 ptr =
 481                     (uint64_t *) cvmx_phys_to_ptr((uint64_t) qptr->
 482                                                   base_ptr_div128 << 7);
 483                 ptr += qptr->index;
 484                 *ptr++ = cmd1;
 485                 if (likely(count))
 486                         *ptr++ = cmd2;
 487                 *ptr = cvmx_ptr_to_phys(new_buffer);
 488                 /*
 489                  * The current buffer is full and has a link to the
 490                  * next buffer. Time to write the rest of the commands
 491                  * into the new buffer.
 492                  */
 493                 qptr->base_ptr_div128 = *ptr >> 7;
 494                 qptr->index = 0;
 495                 if (unlikely(count == 0)) {
 496                         qptr->index = 1;
 497                         new_buffer[0] = cmd2;
 498                 }
 499         }
 500
 501         /* All updates are complete. Release the lock and return */
 502         if (likely(use_locking))
 503                 __cvmx_cmd_queue_unlock(qptr);
 504         return CVMX_CMD_QUEUE_SUCCESS;
 505 }
 506
 507 /**
 508  * Simple function to write three command words to a command
 509  * queue.
 510  *
 511  * @queue_id: Hardware command queue to write to
 512  * @use_locking:
 513  *                 Use internal locking to ensure exclusive access for queue
 514  *                 updates. If you don't use this locking you must ensure
 515  *                 exclusivity some other way. Locking is strongly recommended.
 516  * @cmd1:     Command
 517  * @cmd2:     Command
 518  * @cmd3:     Command
 519  *
 520  * Returns CVMX_CMD_QUEUE_SUCCESS or a failure code
 521  */
 522 static inline cvmx_cmd_queue_result_t cvmx_cmd_queue_write3(cvmx_cmd_queue_id_t
 523                                                             queue_id,
 524                                                             int use_locking,
 525                                                             uint64_t cmd1,
 526                                                             uint64_t cmd2,
 527                                                             uint64_t cmd3)
 528 {
 529         __cvmx_cmd_queue_state_t *qptr = __cvmx_cmd_queue_get_state(queue_id);
 530
 531         /* Make sure nobody else is updating the same queue */
 532         if (likely(use_locking))
 533                 __cvmx_cmd_queue_lock(queue_id, qptr);
 534
 535         /*
 536          * If a max queue length was specified then make sure we don't
 537          * exceed it. If any part of the command would be below the
 538          * limit we allow it.
 539          */
 540         if (CVMX_CMD_QUEUE_ENABLE_MAX_DEPTH && unlikely(qptr->max_depth)) {
 541                 if (unlikely
 542                     (cvmx_cmd_queue_length(queue_id) > (int)qptr->max_depth)) {
 543                         if (likely(use_locking))
 544                                 __cvmx_cmd_queue_unlock(qptr);
 545                         return CVMX_CMD_QUEUE_FULL;
 546                 }
 547         }
 548
 549         /*
 550          * Normally there is plenty of room in the current buffer for
 551          * the command.
 552          */
 553         if (likely(qptr->index + 3 < qptr->pool_size_m1)) {
 554                 uint64_t *ptr =
 555                     (uint64_t *) cvmx_phys_to_ptr((uint64_t) qptr->
 556                                                   base_ptr_div128 << 7);
 557                 ptr += qptr->index;
 558                 qptr->index += 3;
 559                 ptr[0] = cmd1;
 560                 ptr[1] = cmd2;
 561                 ptr[2] = cmd3;
 562         } else {
 563                 uint64_t *ptr;
 564                 /*
 565                  * Figure out how many command words will fit in this
 566                  * buffer. One location will be needed for the next
 567                  * buffer pointer
 568                  */
 569                 int count = qptr->pool_size_m1 - qptr->index;
 570                 /*
 571                  * We need a new command buffer. Fail if there isn't
 572                  * one available
 573                  */
 574                 uint64_t *new_buffer =
 575                     (uint64_t *) cvmx_fpa_alloc(qptr->fpa_pool);
 576                 if (unlikely(new_buffer == NULL)) {
 577                         if (likely(use_locking))
 578                                 __cvmx_cmd_queue_unlock(qptr);
 579                         return CVMX_CMD_QUEUE_NO_MEMORY;
 580                 }
 581                 count--;
 582                 ptr =
 583                     (uint64_t *) cvmx_phys_to_ptr((uint64_t) qptr->
 584                                                   base_ptr_div128 << 7);
 585                 ptr += qptr->index;
 586                 *ptr++ = cmd1;
 587                 if (count) {
 588                         *ptr++ = cmd2;
 589                         if (count > 1)
 590                                 *ptr++ = cmd3;
 591                 }
 592                 *ptr = cvmx_ptr_to_phys(new_buffer);
 593                 /*
 594                  * The current buffer is full and has a link to the
 595                  * next buffer. Time to write the rest of the commands
 596                  * into the new buffer.
 597                  */
 598                 qptr->base_ptr_div128 = *ptr >> 7;
 599                 qptr->index = 0;
 600                 ptr = new_buffer;
 601                 if (count == 0) {
 602                         *ptr++ = cmd2;
 603                         qptr->index++;
 604                 }
 605                 if (count < 2) {
 606                         *ptr++ = cmd3;
 607                         qptr->index++;
 608                 }
 609         }
 610
 611         /* All updates are complete. Release the lock and return */
 612         if (likely(use_locking))
 613                 __cvmx_cmd_queue_unlock(qptr);
 614         return CVMX_CMD_QUEUE_SUCCESS;
 615 }
 616
 617 #endif /* __CVMX_CMD_QUEUE_H__ */