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