linux/drivers/scsi/isci/unsolicited_frame_control.c

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/*
* This file is provided under a dual BSD/GPLv2 license. When using or
* redistributing this file, you may do so under either license.
*
* GPL LICENSE SUMMARY
*
* Copyright(c) 2008 - 2011 Intel Corporation. All rights reserved.
*
* This program is free software; you can redistribute it and/or modify
* it under the terms of version 2 of the GNU General Public License as
* published by the Free Software Foundation.
*
* This program is distributed in the hope that it will be useful, but
* WITHOUT ANY WARRANTY; without even the implied warranty of
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
* General Public License for more details.
*
* You should have received a copy of the GNU General Public License
* along with this program; if not, write to the Free Software
* Foundation, Inc., 51 Franklin St - Fifth Floor, Boston, MA 02110-1301 USA.
* The full GNU General Public License is included in this distribution
* in the file called LICENSE.GPL.
*
* BSD LICENSE
*
* Copyright(c) 2008 - 2011 Intel Corporation. All rights reserved.
* All rights reserved.
*
* Redistribution and use in source and binary forms, with or without
* modification, are permitted provided that the following conditions
* are met:
*
* * Redistributions of source code must retain the above copyright
* notice, this list of conditions and the following disclaimer.
* * Redistributions in binary form must reproduce the above copyright
* notice, this list of conditions and the following disclaimer in
* the documentation and/or other materials provided with the
* distribution.
* * Neither the name of Intel Corporation nor the names of its
* contributors may be used to endorse or promote products derived
* from this software without specific prior written permission.
*
* THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
* "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
* LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
* A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
* OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
* SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
* LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
* DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
* THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
* (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
* OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
*/
#include "host.h"
#include "unsolicited_frame_control.h"
#include "registers.h"
int scic_sds_unsolicited_frame_control_construct(struct isci_host *ihost)
{
struct scic_sds_unsolicited_frame_control *uf_control = &ihost->uf_control;
struct scic_sds_unsolicited_frame *uf;
u32 buf_len, header_len, i;
dma_addr_t dma;
size_t size;
void *virt;
/*
* Prepare all of the memory sizes for the UF headers, UF address
* table, and UF buffers themselves.
*/
buf_len = SCU_MAX_UNSOLICITED_FRAMES * SCU_UNSOLICITED_FRAME_BUFFER_SIZE;
header_len = SCU_MAX_UNSOLICITED_FRAMES * sizeof(struct scu_unsolicited_frame_header);
size = buf_len + header_len + SCU_MAX_UNSOLICITED_FRAMES * sizeof(dma_addr_t);
/*
* The Unsolicited Frame buffers are set at the start of the UF
* memory descriptor entry. The headers and address table will be
* placed after the buffers.
*/
virt = dmam_alloc_coherent(&ihost->pdev->dev, size, &dma, GFP_KERNEL);
if (!virt)
return -ENOMEM;
/*
* Program the location of the UF header table into the SCU.
* Notes:
* - The address must align on a 64-byte boundary. Guaranteed to be
* on 64-byte boundary already 1KB boundary for unsolicited frames.
* - Program unused header entries to overlap with the last
* unsolicited frame. The silicon will never DMA to these unused
* headers, since we program the UF address table pointers to
* NULL.
*/
uf_control->headers.physical_address = dma + buf_len;
uf_control->headers.array = virt + buf_len;
/*
* Program the location of the UF address table into the SCU.
* Notes:
* - The address must align on a 64-bit boundary. Guaranteed to be on 64
* byte boundary already due to above programming headers being on a
* 64-bit boundary and headers are on a 64-bytes in size.
*/
uf_control->address_table.physical_address = dma + buf_len + header_len;
uf_control->address_table.array = virt + buf_len + header_len;
uf_control->get = 0;
/*
* UF buffer requirements are:
* - The last entry in the UF queue is not NULL.
* - There is a power of 2 number of entries (NULL or not-NULL)
* programmed into the queue.
* - Aligned on a 1KB boundary. */
/*
* Program the actual used UF buffers into the UF address table and
* the controller's array of UFs.
*/
for (i = 0; i < SCU_MAX_UNSOLICITED_FRAMES; i++) {
uf = &uf_control->buffers.array[i];
uf_control->address_table.array[i] = dma;
uf->buffer = virt;
uf->header = &uf_control->headers.array[i];
uf->state = UNSOLICITED_FRAME_EMPTY;
/*
* Increment the address of the physical and virtual memory
* pointers. Everything is aligned on 1k boundary with an
* increment of 1k.
*/
virt += SCU_UNSOLICITED_FRAME_BUFFER_SIZE;
dma += SCU_UNSOLICITED_FRAME_BUFFER_SIZE;
}
return 0;
}
/**
* This method returns the frame header for the specified frame index.
* @uf_control:
* @frame_index:
* @frame_header:
*
* enum sci_status
*/
enum sci_status scic_sds_unsolicited_frame_control_get_header(
struct scic_sds_unsolicited_frame_control *uf_control,
u32 frame_index,
void **frame_header)
{
if (frame_index < SCU_MAX_UNSOLICITED_FRAMES) {
/*
* Skip the first word in the frame since this is a controll word used
* by the hardware. */
*frame_header = &uf_control->buffers.array[frame_index].header->data;
return SCI_SUCCESS;
}
return SCI_FAILURE_INVALID_PARAMETER_VALUE;
}
/**
* This method returns the frame buffer for the specified frame index.
* @uf_control:
* @frame_index:
* @frame_buffer:
*
* enum sci_status
*/
enum sci_status scic_sds_unsolicited_frame_control_get_buffer(
struct scic_sds_unsolicited_frame_control *uf_control,
u32 frame_index,
void **frame_buffer)
{
if (frame_index < SCU_MAX_UNSOLICITED_FRAMES) {
*frame_buffer = uf_control->buffers.array[frame_index].buffer;
return SCI_SUCCESS;
}
return SCI_FAILURE_INVALID_PARAMETER_VALUE;
}
/**
* This method releases the frame once this is done the frame is available for
* re-use by the hardware. The data contained in the frame header and frame
* buffer is no longer valid.
* @uf_control: This parameter specifies the UF control object
* @frame_index: This parameter specifies the frame index to attempt to release.
*
* This method returns an indication to the caller as to whether the
* unsolicited frame get pointer should be updated.
*/
bool scic_sds_unsolicited_frame_control_release_frame(
struct scic_sds_unsolicited_frame_control *uf_control,
u32 frame_index)
{
u32 frame_get;
u32 frame_cycle;
frame_get = uf_control->get & (SCU_MAX_UNSOLICITED_FRAMES - 1);
frame_cycle = uf_control->get & SCU_MAX_UNSOLICITED_FRAMES;
/*
* In the event there are NULL entries in the UF table, we need to
* advance the get pointer in order to find out if this frame should
* be released (i.e. update the get pointer)
*/
while (lower_32_bits(uf_control->address_table.array[frame_get]) == 0 &&
upper_32_bits(uf_control->address_table.array[frame_get]) == 0 &&
frame_get < SCU_MAX_UNSOLICITED_FRAMES)
frame_get++;
/*
* The table has a NULL entry as it's last element. This is
* illegal.
*/
BUG_ON(frame_get >= SCU_MAX_UNSOLICITED_FRAMES);
if (frame_index >= SCU_MAX_UNSOLICITED_FRAMES)
return false;
uf_control->buffers.array[frame_index].state = UNSOLICITED_FRAME_RELEASED;
if (frame_get != frame_index) {
/*
* Frames remain in use until we advance the get pointer
* so there is nothing we can do here
*/
return false;
}
/*
* The frame index is equal to the current get pointer so we
* can now free up all of the frame entries that
*/
while (uf_control->buffers.array[frame_get].state == UNSOLICITED_FRAME_RELEASED) {
uf_control->buffers.array[frame_get].state = UNSOLICITED_FRAME_EMPTY;
if (frame_get+1 == SCU_MAX_UNSOLICITED_FRAMES-1) {
frame_cycle ^= SCU_MAX_UNSOLICITED_FRAMES;
frame_get = 0;
} else
frame_get++;
}
uf_control->get = SCU_UFQGP_GEN_BIT(ENABLE_BIT) | frame_cycle | frame_get;
return true;
}