scsi/isci/unsolicited_frame_control.c

0001 /*
0002  * This file is provided under a dual BSD/GPLv2 license.  When using or
0003  * redistributing this file, you may do so under either license.
0004  *
0005  * GPL LICENSE SUMMARY
0006  *
0007  * Copyright(c) 2008 - 2011 Intel Corporation. All rights reserved.
0008  *
0009  * This program is free software; you can redistribute it and/or modify
0010  * it under the terms of version 2 of the GNU General Public License as
0011  * published by the Free Software Foundation.
0012  *
0013  * This program is distributed in the hope that it will be useful, but
0014  * WITHOUT ANY WARRANTY; without even the implied warranty of
0015  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
0016  * General Public License for more details.
0017  *
0018  * You should have received a copy of the GNU General Public License
0019  * along with this program; if not, write to the Free Software
0020  * Foundation, Inc., 51 Franklin St - Fifth Floor, Boston, MA 02110-1301 USA.
0021  * The full GNU General Public License is included in this distribution
0022  * in the file called LICENSE.GPL.
0023  *
0024  * BSD LICENSE
0025  *
0026  * Copyright(c) 2008 - 2011 Intel Corporation. All rights reserved.
0027  * All rights reserved.
0028  *
0029  * Redistribution and use in source and binary forms, with or without
0030  * modification, are permitted provided that the following conditions
0031  * are met:
0032  *
0033  *   * Redistributions of source code must retain the above copyright
0034  *     notice, this list of conditions and the following disclaimer.
0035  *   * Redistributions in binary form must reproduce the above copyright
0036  *     notice, this list of conditions and the following disclaimer in
0037  *     the documentation and/or other materials provided with the
0038  *     distribution.
0039  *   * Neither the name of Intel Corporation nor the names of its
0040  *     contributors may be used to endorse or promote products derived
0041  *     from this software without specific prior written permission.
0042  *
0043  * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
0044  * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
0045  * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
0046  * A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
0047  * OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
0048  * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
0049  * LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
0050  * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
0051  * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
0052  * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
0053  * OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
0054  */
0055
0056 #include "host.h"
0057 #include "unsolicited_frame_control.h"
0058 #include "registers.h"
0059
0060 void sci_unsolicited_frame_control_construct(struct isci_host *ihost)
0061 {
0062     struct sci_unsolicited_frame_control *uf_control = &ihost->uf_control;
0063     struct sci_unsolicited_frame *uf;
0064     dma_addr_t dma = ihost->ufi_dma;
0065     void *virt = ihost->ufi_buf;
0066     int i;
0067
0068     /*
0069      * The Unsolicited Frame buffers are set at the start of the UF
0070      * memory descriptor entry. The headers and address table will be
0071      * placed after the buffers.
0072      */
0073
0074     /*
0075      * Program the location of the UF header table into the SCU.
0076      * Notes:
0077      * - The address must align on a 64-byte boundary. Guaranteed to be
0078      *   on 64-byte boundary already 1KB boundary for unsolicited frames.
0079      * - Program unused header entries to overlap with the last
0080      *   unsolicited frame.  The silicon will never DMA to these unused
0081      *   headers, since we program the UF address table pointers to
0082      *   NULL.
0083      */
0084     uf_control->headers.physical_address = dma + SCI_UFI_BUF_SIZE;
0085     uf_control->headers.array = virt + SCI_UFI_BUF_SIZE;
0086
0087     /*
0088      * Program the location of the UF address table into the SCU.
0089      * Notes:
0090      * - The address must align on a 64-bit boundary. Guaranteed to be on 64
0091      *   byte boundary already due to above programming headers being on a
0092      *   64-bit boundary and headers are on a 64-bytes in size.
0093      */
0094     uf_control->address_table.physical_address = dma + SCI_UFI_BUF_SIZE + SCI_UFI_HDR_SIZE;
0095     uf_control->address_table.array = virt + SCI_UFI_BUF_SIZE + SCI_UFI_HDR_SIZE;
0096     uf_control->get = 0;
0097
0098     /*
0099      * UF buffer requirements are:
0100      * - The last entry in the UF queue is not NULL.
0101      * - There is a power of 2 number of entries (NULL or not-NULL)
0102      *   programmed into the queue.
0103      * - Aligned on a 1KB boundary. */
0104
0105     /*
0106      * Program the actual used UF buffers into the UF address table and
0107      * the controller's array of UFs.
0108      */
0109     for (i = 0; i < SCU_MAX_UNSOLICITED_FRAMES; i++) {
0110         uf = &uf_control->buffers.array[i];
0111
0112         uf_control->address_table.array[i] = dma;
0113
0114         uf->buffer = virt;
0115         uf->header = &uf_control->headers.array[i];
0116         uf->state  = UNSOLICITED_FRAME_EMPTY;
0117
0118         /*
0119          * Increment the address of the physical and virtual memory
0120          * pointers. Everything is aligned on 1k boundary with an
0121          * increment of 1k.
0122          */
0123         virt += SCU_UNSOLICITED_FRAME_BUFFER_SIZE;
0124         dma += SCU_UNSOLICITED_FRAME_BUFFER_SIZE;
0125     }
0126 }
0127
0128 enum sci_status sci_unsolicited_frame_control_get_header(struct sci_unsolicited_frame_control *uf_control,
0129                              u32 frame_index,
0130                              void **frame_header)
0131 {
0132     if (frame_index < SCU_MAX_UNSOLICITED_FRAMES) {
0133         /* Skip the first word in the frame since this is a controll word used
0134          * by the hardware.
0135          */
0136         *frame_header = &uf_control->buffers.array[frame_index].header->data;
0137
0138         return SCI_SUCCESS;
0139     }
0140
0141     return SCI_FAILURE_INVALID_PARAMETER_VALUE;
0142 }
0143
0144 enum sci_status sci_unsolicited_frame_control_get_buffer(struct sci_unsolicited_frame_control *uf_control,
0145                              u32 frame_index,
0146                              void **frame_buffer)
0147 {
0148     if (frame_index < SCU_MAX_UNSOLICITED_FRAMES) {
0149         *frame_buffer = uf_control->buffers.array[frame_index].buffer;
0150
0151         return SCI_SUCCESS;
0152     }
0153
0154     return SCI_FAILURE_INVALID_PARAMETER_VALUE;
0155 }
0156
0157 bool sci_unsolicited_frame_control_release_frame(struct sci_unsolicited_frame_control *uf_control,
0158                          u32 frame_index)
0159 {
0160     u32 frame_get;
0161     u32 frame_cycle;
0162
0163     frame_get   = uf_control->get & (SCU_MAX_UNSOLICITED_FRAMES - 1);
0164     frame_cycle = uf_control->get & SCU_MAX_UNSOLICITED_FRAMES;
0165
0166     /*
0167      * In the event there are NULL entries in the UF table, we need to
0168      * advance the get pointer in order to find out if this frame should
0169      * be released (i.e. update the get pointer)
0170      */
0171     while (lower_32_bits(uf_control->address_table.array[frame_get]) == 0 &&
0172            upper_32_bits(uf_control->address_table.array[frame_get]) == 0 &&
0173            frame_get < SCU_MAX_UNSOLICITED_FRAMES)
0174         frame_get++;
0175
0176     /*
0177      * The table has a NULL entry as it's last element.  This is
0178      * illegal.
0179      */
0180     BUG_ON(frame_get >= SCU_MAX_UNSOLICITED_FRAMES);
0181     if (frame_index >= SCU_MAX_UNSOLICITED_FRAMES)
0182         return false;
0183
0184     uf_control->buffers.array[frame_index].state = UNSOLICITED_FRAME_RELEASED;
0185
0186     if (frame_get != frame_index) {
0187         /*
0188          * Frames remain in use until we advance the get pointer
0189          * so there is nothing we can do here
0190          */
0191         return false;
0192     }
0193
0194     /*
0195      * The frame index is equal to the current get pointer so we
0196      * can now free up all of the frame entries that
0197      */
0198     while (uf_control->buffers.array[frame_get].state == UNSOLICITED_FRAME_RELEASED) {
0199         uf_control->buffers.array[frame_get].state = UNSOLICITED_FRAME_EMPTY;
0200
0201         if (frame_get+1 == SCU_MAX_UNSOLICITED_FRAMES-1) {
0202             frame_cycle ^= SCU_MAX_UNSOLICITED_FRAMES;
0203             frame_get = 0;
0204         } else
0205             frame_get++;
0206     }
0207
0208     uf_control->get = SCU_UFQGP_GEN_BIT(ENABLE_BIT) | frame_cycle | frame_get;
0209
0210     return true;
0211 }