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 int sci_unsolicited_frame_control_construct(struct isci_host *ihost)
  61 {
  62         struct sci_unsolicited_frame_control *uf_control = &ihost->uf_control;
  63         struct sci_unsolicited_frame *uf;
  64         u32 buf_len, header_len, i;
  65         dma_addr_t dma;
  66         size_t size;
  67         void *virt;
  68
  69         /*
  70          * Prepare all of the memory sizes for the UF headers, UF address
  71          * table, and UF buffers themselves.
  72          */
  73         buf_len = SCU_MAX_UNSOLICITED_FRAMES * SCU_UNSOLICITED_FRAME_BUFFER_SIZE;
  74         header_len = SCU_MAX_UNSOLICITED_FRAMES * sizeof(struct scu_unsolicited_frame_header);
  75         size = buf_len + header_len + SCU_MAX_UNSOLICITED_FRAMES * sizeof(uf_control->address_table.array[0]);
  76
  77         /*
  78          * The Unsolicited Frame buffers are set at the start of the UF
  79          * memory descriptor entry. The headers and address table will be
  80          * placed after the buffers.
  81          */
  82         virt = dmam_alloc_coherent(&ihost->pdev->dev, size, &dma, GFP_KERNEL);
  83         if (!virt)
  84                 return -ENOMEM;
  85
  86         /*
  87          * Program the location of the UF header table into the SCU.
  88          * Notes:
  89          * - The address must align on a 64-byte boundary. Guaranteed to be
  90          *   on 64-byte boundary already 1KB boundary for unsolicited frames.
  91          * - Program unused header entries to overlap with the last
  92          *   unsolicited frame.  The silicon will never DMA to these unused
  93          *   headers, since we program the UF address table pointers to
  94          *   NULL.
  95          */
  96         uf_control->headers.physical_address = dma + buf_len;
  97         uf_control->headers.array = virt + buf_len;
  98
  99         /*
 100          * Program the location of the UF address table into the SCU.
 101          * Notes:
 102          * - The address must align on a 64-bit boundary. Guaranteed to be on 64
 103          *   byte boundary already due to above programming headers being on a
 104          *   64-bit boundary and headers are on a 64-bytes in size.
 105          */
 106         uf_control->address_table.physical_address = dma + buf_len + header_len;
 107         uf_control->address_table.array = virt + buf_len + header_len;
 108         uf_control->get = 0;
 109
 110         /*
 111          * UF buffer requirements are:
 112          * - The last entry in the UF queue is not NULL.
 113          * - There is a power of 2 number of entries (NULL or not-NULL)
 114          *   programmed into the queue.
 115          * - Aligned on a 1KB boundary. */
 116
 117         /*
 118          * Program the actual used UF buffers into the UF address table and
 119          * the controller's array of UFs.
 120          */
 121         for (i = 0; i < SCU_MAX_UNSOLICITED_FRAMES; i++) {
 122                 uf = &uf_control->buffers.array[i];
 123
 124                 uf_control->address_table.array[i] = dma;
 125
 126                 uf->buffer = virt;
 127                 uf->header = &uf_control->headers.array[i];
 128                 uf->state  = UNSOLICITED_FRAME_EMPTY;
 129
 130                 /*
 131                  * Increment the address of the physical and virtual memory
 132                  * pointers. Everything is aligned on 1k boundary with an
 133                  * increment of 1k.
 134                  */
 135                 virt += SCU_UNSOLICITED_FRAME_BUFFER_SIZE;
 136                 dma += SCU_UNSOLICITED_FRAME_BUFFER_SIZE;
 137         }
 138
 139         return 0;
 140 }
 141
 142 enum sci_status sci_unsolicited_frame_control_get_header(struct sci_unsolicited_frame_control *uf_control,
 143                                                          u32 frame_index,
 144                                                          void **frame_header)
 145 {
 146         if (frame_index < SCU_MAX_UNSOLICITED_FRAMES) {
 147                 /* Skip the first word in the frame since this is a controll word used
 148                  * by the hardware.
 149                  */
 150                 *frame_header = &uf_control->buffers.array[frame_index].header->data;
 151
 152                 return SCI_SUCCESS;
 153         }
 154
 155         return SCI_FAILURE_INVALID_PARAMETER_VALUE;
 156 }
 157
 158 enum sci_status sci_unsolicited_frame_control_get_buffer(struct sci_unsolicited_frame_control *uf_control,
 159                                                          u32 frame_index,
 160                                                          void **frame_buffer)
 161 {
 162         if (frame_index < SCU_MAX_UNSOLICITED_FRAMES) {
 163                 *frame_buffer = uf_control->buffers.array[frame_index].buffer;
 164
 165                 return SCI_SUCCESS;
 166         }
 167
 168         return SCI_FAILURE_INVALID_PARAMETER_VALUE;
 169 }
 170
 171 bool sci_unsolicited_frame_control_release_frame(struct sci_unsolicited_frame_control *uf_control,
 172                                                  u32 frame_index)
 173 {
 174         u32 frame_get;
 175         u32 frame_cycle;
 176
 177         frame_get   = uf_control->get & (SCU_MAX_UNSOLICITED_FRAMES - 1);
 178         frame_cycle = uf_control->get & SCU_MAX_UNSOLICITED_FRAMES;
 179
 180         /*
 181          * In the event there are NULL entries in the UF table, we need to
 182          * advance the get pointer in order to find out if this frame should
 183          * be released (i.e. update the get pointer)
 184          */
 185         while (lower_32_bits(uf_control->address_table.array[frame_get]) == 0 &&
 186                upper_32_bits(uf_control->address_table.array[frame_get]) == 0 &&
 187                frame_get < SCU_MAX_UNSOLICITED_FRAMES)
 188                 frame_get++;
 189
 190         /*
 191          * The table has a NULL entry as it's last element.  This is
 192          * illegal.
 193          */
 194         BUG_ON(frame_get >= SCU_MAX_UNSOLICITED_FRAMES);
 195         if (frame_index >= SCU_MAX_UNSOLICITED_FRAMES)
 196                 return false;
 197
 198         uf_control->buffers.array[frame_index].state = UNSOLICITED_FRAME_RELEASED;
 199
 200         if (frame_get != frame_index) {
 201                 /*
 202                  * Frames remain in use until we advance the get pointer
 203                  * so there is nothing we can do here
 204                  */
 205                 return false;
 206         }
 207
 208         /*
 209          * The frame index is equal to the current get pointer so we
 210          * can now free up all of the frame entries that
 211          */
 212         while (uf_control->buffers.array[frame_get].state == UNSOLICITED_FRAME_RELEASED) {
 213                 uf_control->buffers.array[frame_get].state = UNSOLICITED_FRAME_EMPTY;
 214
 215                 if (frame_get+1 == SCU_MAX_UNSOLICITED_FRAMES-1) {
 216                         frame_cycle ^= SCU_MAX_UNSOLICITED_FRAMES;
 217                         frame_get = 0;
 218                 } else
 219                         frame_get++;
 220         }
 221
 222         uf_control->get = SCU_UFQGP_GEN_BIT(ENABLE_BIT) | frame_cycle | frame_get;
 223
 224         return true;
 225 }