drivers/scsi/isci/unsolicited_frame_control.c

   1 /*
   2  * This file is provided under a dual BSD/GPLv2 license.  When using or
   3  * redistributing this file, you may do so under either license.
   4  *
   5  * GPL LICENSE SUMMARY
   6  *
   7  * Copyright(c) 2008 - 2011 Intel Corporation. All rights reserved.
   8  *
   9  * This program is free software; you can redistribute it and/or modify
  10  * it under the terms of version 2 of the GNU General Public License as
  11  * published by the Free Software Foundation.
  12  *
  13  * This program is distributed in the hope that it will be useful, but
  14  * WITHOUT ANY WARRANTY; without even the implied warranty of
  15  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
  16  * General Public License for more details.
  17  *
  18  * You should have received a copy of the GNU General Public License
  19  * along with this program; if not, write to the Free Software
  20  * Foundation, Inc., 51 Franklin St - Fifth Floor, Boston, MA 02110-1301 USA.
  21  * The full GNU General Public License is included in this distribution
  22  * in the file called LICENSE.GPL.
  23  *
  24  * BSD LICENSE
  25  *
  26  * Copyright(c) 2008 - 2011 Intel Corporation. All rights reserved.
  27  * All rights reserved.
  28  *
  29  * Redistribution and use in source and binary forms, with or without
  30  * modification, are permitted provided that the following conditions
  31  * are met:
  32  *
  33  *   * Redistributions of source code must retain the above copyright
  34  *     notice, this list of conditions and the following disclaimer.
  35  *   * Redistributions in binary form must reproduce the above copyright
  36  *     notice, this list of conditions and the following disclaimer in
  37  *     the documentation and/or other materials provided with the
  38  *     distribution.
  39  *   * Neither the name of Intel Corporation nor the names of its
  40  *     contributors may be used to endorse or promote products derived
  41  *     from this software without specific prior written permission.
  42  *
  43  * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
  44  * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
  45  * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
  46  * A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
  47  * OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
  48  * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
  49  * LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
  50  * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
  51  * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
  52  * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
  53  * OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
  54  */
  55
  56 #include "host.h"
  57 #include "unsolicited_frame_control.h"
  58 #include "registers.h"
  59
  60 /**
  61  * This method will program the unsolicited frames (UFs) into the UF address
  62  *    table and construct the UF frame structure being modeled in the core.  It
  63  *    will handle the case where some of the UFs are not being used and thus
  64  *    should have entries programmed to zero in the address table.
  65  * @uf_control: This parameter specifies the unsolicted frame control object
  66  *    for which to construct the unsolicited frames objects.
  67  * @uf_buffer_phys_address: This parameter specifies the physical address for
  68  *    the first unsolicited frame buffer.
  69  * @uf_buffer_virt_address: This parameter specifies the virtual address for
  70  *    the first unsolicited frame buffer.
  71  * @unused_uf_header_entries: This parameter specifies the number of unused UF
  72  *    headers.  This value can be non-zero when there are a non-power of 2
  73  *    number of unsolicited frames being supported.
  74  * @used_uf_header_entries: This parameter specifies the number of actually
  75  *    utilized UF headers.
  76  *
  77  */
  78 static void scic_sds_unsolicited_frame_control_construct_frames(
  79         struct scic_sds_unsolicited_frame_control *uf_control,
  80         dma_addr_t uf_buffer_phys_address,
  81         void *uf_buffer_virt_address,
  82         u32 unused_uf_header_entries,
  83         u32 used_uf_header_entries)
  84 {
  85         u32 index;
  86         struct scic_sds_unsolicited_frame *uf;
  87
  88         /*
  89          * Program the unused buffers into the UF address table and the
  90          * controller's array of UFs.
  91          */
  92         for (index = 0; index < unused_uf_header_entries; index++) {
  93                 uf = &uf_control->buffers.array[index];
  94
  95                 uf->buffer = NULL;
  96                 uf_control->address_table.array[index] = 0;
  97                 uf->header = &uf_control->headers.array[index];
  98                 uf->state  = UNSOLICITED_FRAME_EMPTY;
  99         }
 100
 101         /*
 102          * Program the actual used UF buffers into the UF address table and
 103          * the controller's array of UFs.
 104          */
 105         for (index = unused_uf_header_entries;
 106              index < unused_uf_header_entries + used_uf_header_entries;
 107              index++) {
 108                 uf = &uf_control->buffers.array[index];
 109
 110                 uf_control->address_table.array[index] = uf_buffer_phys_address;
 111
 112                 uf->buffer = uf_buffer_virt_address;
 113                 uf->header = &uf_control->headers.array[index];
 114                 uf->state  = UNSOLICITED_FRAME_EMPTY;
 115
 116                 /*
 117                  * Increment the address of the physical and virtual memory
 118                  * pointers. Everything is aligned on 1k boundary with an
 119                  * increment of 1k.
 120                  */
 121                 uf_buffer_virt_address += SCU_UNSOLICITED_FRAME_BUFFER_SIZE;
 122                 uf_buffer_phys_address += SCU_UNSOLICITED_FRAME_BUFFER_SIZE;
 123         }
 124 }
 125
 126 int scic_sds_unsolicited_frame_control_construct(struct scic_sds_controller *scic)
 127 {
 128         struct scic_sds_unsolicited_frame_control *uf_control = &scic->uf_control;
 129         u32 unused_uf_header_entries;
 130         u32 used_uf_header_entries;
 131         u32 used_uf_buffer_bytes;
 132         u32 unused_uf_header_bytes;
 133         u32 used_uf_header_bytes;
 134         dma_addr_t uf_buffer_phys_address;
 135         void *uf_buffer_virt_address;
 136         size_t size;
 137
 138         /*
 139          * The UF buffer address table size must be programmed to a power
 140          * of 2.  Find the first power of 2 that is equal to or greater then
 141          * the number of unsolicited frame buffers to be utilized.
 142          */
 143         uf_control->address_table.count = SCU_MIN_UF_TABLE_ENTRIES;
 144         while (uf_control->address_table.count < uf_control->buffers.count &&
 145                uf_control->address_table.count < SCU_ABSOLUTE_MAX_UNSOLICITED_FRAMES)
 146                 uf_control->address_table.count <<= 1;
 147
 148         /*
 149          * Prepare all of the memory sizes for the UF headers, UF address
 150          * table, and UF buffers themselves.
 151          */
 152         used_uf_buffer_bytes     = uf_control->buffers.count
 153                                    * SCU_UNSOLICITED_FRAME_BUFFER_SIZE;
 154         unused_uf_header_entries = uf_control->address_table.count
 155                                    - uf_control->buffers.count;
 156         used_uf_header_entries   = uf_control->buffers.count;
 157         unused_uf_header_bytes   = unused_uf_header_entries
 158                                    * sizeof(struct scu_unsolicited_frame_header);
 159         used_uf_header_bytes     = used_uf_header_entries
 160                                    * sizeof(struct scu_unsolicited_frame_header);
 161
 162         size = used_uf_buffer_bytes + used_uf_header_bytes +
 163                         uf_control->address_table.count * sizeof(dma_addr_t);
 164
 165
 166         /*
 167          * The Unsolicited Frame buffers are set at the start of the UF
 168          * memory descriptor entry. The headers and address table will be
 169          * placed after the buffers.
 170          */
 171         uf_buffer_virt_address = dmam_alloc_coherent(scic_to_dev(scic), size,
 172                                                         &uf_buffer_phys_address, GFP_KERNEL);
 173         if (!uf_buffer_virt_address)
 174                 return -ENOMEM;
 175
 176         /*
 177          * Program the location of the UF header table into the SCU.
 178          * Notes:
 179          * - The address must align on a 64-byte boundary. Guaranteed to be
 180          *   on 64-byte boundary already 1KB boundary for unsolicited frames.
 181          * - Program unused header entries to overlap with the last
 182          *   unsolicited frame.  The silicon will never DMA to these unused
 183          *   headers, since we program the UF address table pointers to
 184          *   NULL.
 185          */
 186         uf_control->headers.physical_address =
 187                                 uf_buffer_phys_address +
 188                                 used_uf_buffer_bytes -
 189                                 unused_uf_header_bytes;
 190
 191         uf_control->headers.array =
 192                                 uf_buffer_virt_address +
 193                                 used_uf_buffer_bytes -
 194                                 unused_uf_header_bytes;
 195
 196         /*
 197          * Program the location of the UF address table into the SCU.
 198          * Notes:
 199          * - The address must align on a 64-bit boundary. Guaranteed to be on 64
 200          *   byte boundary already due to above programming headers being on a
 201          *   64-bit boundary and headers are on a 64-bytes in size.
 202          */
 203         uf_control->address_table.physical_address =
 204                                 uf_buffer_phys_address +
 205                                 used_uf_buffer_bytes +
 206                                 used_uf_header_bytes;
 207
 208         uf_control->address_table.array =
 209                                 uf_buffer_virt_address +
 210                                 used_uf_buffer_bytes +
 211                                 used_uf_header_bytes;
 212
 213         uf_control->get = 0;
 214
 215         /*
 216          * UF buffer requirements are:
 217          * - The last entry in the UF queue is not NULL.
 218          * - There is a power of 2 number of entries (NULL or not-NULL)
 219          *   programmed into the queue.
 220          * - Aligned on a 1KB boundary. */
 221
 222         /*
 223          * If the user provided less then the maximum amount of memory,
 224          * then be sure that we programm the first entries in the UF
 225          * address table to NULL. */
 226         scic_sds_unsolicited_frame_control_construct_frames(
 227                 uf_control,
 228                 uf_buffer_phys_address,
 229                 uf_buffer_virt_address,
 230                 unused_uf_header_entries,
 231                 used_uf_header_entries
 232                 );
 233
 234         return 0;
 235 }
 236
 237 /**
 238  * This method returns the frame header for the specified frame index.
 239  * @uf_control:
 240  * @frame_index:
 241  * @frame_header:
 242  *
 243  * enum sci_status
 244  */
 245 enum sci_status scic_sds_unsolicited_frame_control_get_header(
 246         struct scic_sds_unsolicited_frame_control *uf_control,
 247         u32 frame_index,
 248         void **frame_header)
 249 {
 250         if (frame_index < uf_control->address_table.count) {
 251                 /*
 252                  * Skip the first word in the frame since this is a controll word used
 253                  * by the hardware. */
 254                 *frame_header = &uf_control->buffers.array[frame_index].header->data;
 255
 256                 return SCI_SUCCESS;
 257         }
 258
 259         return SCI_FAILURE_INVALID_PARAMETER_VALUE;
 260 }
 261
 262 /**
 263  * This method returns the frame buffer for the specified frame index.
 264  * @uf_control:
 265  * @frame_index:
 266  * @frame_buffer:
 267  *
 268  * enum sci_status
 269  */
 270 enum sci_status scic_sds_unsolicited_frame_control_get_buffer(
 271         struct scic_sds_unsolicited_frame_control *uf_control,
 272         u32 frame_index,
 273         void **frame_buffer)
 274 {
 275         if (frame_index < uf_control->address_table.count) {
 276                 *frame_buffer = uf_control->buffers.array[frame_index].buffer;
 277
 278                 return SCI_SUCCESS;
 279         }
 280
 281         return SCI_FAILURE_INVALID_PARAMETER_VALUE;
 282 }
 283
 284 /**
 285  * This method releases the frame once this is done the frame is available for
 286  *    re-use by the hardware.  The data contained in the frame header and frame
 287  *    buffer is no longer valid.
 288  * @uf_control: This parameter specifies the UF control object
 289  * @frame_index: This parameter specifies the frame index to attempt to release.
 290  *
 291  * This method returns an indication to the caller as to whether the
 292  * unsolicited frame get pointer should be updated.
 293  */
 294 bool scic_sds_unsolicited_frame_control_release_frame(
 295         struct scic_sds_unsolicited_frame_control *uf_control,
 296         u32 frame_index)
 297 {
 298         u32 frame_get;
 299         u32 frame_cycle;
 300
 301         frame_get   = uf_control->get & (uf_control->address_table.count - 1);
 302         frame_cycle = uf_control->get & uf_control->address_table.count;
 303
 304         /*
 305          * In the event there are NULL entries in the UF table, we need to
 306          * advance the get pointer in order to find out if this frame should
 307          * be released (i.e. update the get pointer). */
 308         while (((lower_32_bits(uf_control->address_table.array[frame_get])
 309                                         == 0) &&
 310                 (upper_32_bits(uf_control->address_table.array[frame_get])
 311                                         == 0)) &&
 312                (frame_get < uf_control->address_table.count))
 313                 frame_get++;
 314
 315         /*
 316          * The table has a NULL entry as it's last element.  This is
 317          * illegal. */
 318         BUG_ON(frame_get >= uf_control->address_table.count);
 319
 320         if (frame_index < uf_control->address_table.count) {
 321                 uf_control->buffers.array[frame_index].state = UNSOLICITED_FRAME_RELEASED;
 322
 323                 /*
 324                  * The frame index is equal to the current get pointer so we
 325                  * can now free up all of the frame entries that */
 326                 if (frame_get == frame_index) {
 327                         while (
 328                                 uf_control->buffers.array[frame_get].state
 329                                 == UNSOLICITED_FRAME_RELEASED
 330                                 ) {
 331                                 uf_control->buffers.array[frame_get].state = UNSOLICITED_FRAME_EMPTY;
 332
 333                                 INCREMENT_QUEUE_GET(
 334                                         frame_get,
 335                                         frame_cycle,
 336                                         uf_control->address_table.count - 1,
 337                                         uf_control->address_table.count
 338                                         );
 339                         }
 340
 341                         uf_control->get =
 342                                 (SCU_UFQGP_GEN_BIT(ENABLE_BIT) | frame_cycle | frame_get);
 343
 344                         return true;
 345                 } else {
 346                         /*
 347                          * Frames remain in use until we advance the get pointer
 348                          * so there is nothing we can do here */
 349                 }
 350         }
 351
 352         return false;
 353 }
 354