xref: /freebsd-10-stable/sys/dev/isci/scil/scic_sds_unsolicited_frame_control.c

/*-
 * 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.
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 *
 * 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,
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 * LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
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 */

#include <sys/cdefs.h>
__FBSDID("$FreeBSD$");

/**
 * @file
 *
 * @brief This file contains the implementation of the
 *        SCIC_SDS_UNSOLICITED_FRAME_CONTROL object and it's public,
 *        protected, and private methods.
 */

#include <dev/isci/scil/scic_sds_unsolicited_frame_control.h>
#include <dev/isci/scil/scu_registers.h>
#include <dev/isci/scil/scic_sds_controller.h>
#include <dev/isci/scil/scic_user_callback.h>
#include <dev/isci/scil/sci_util.h>

/**
 * @brief The UF buffer address table size must be programmed to a power
 *        of 2.  Find the first power of 2 that is equal to or greater then
 *        the number of unsolicited frame buffers to be utilized.
 *
 * @param[in,out] uf_control This parameter specifies the UF control
 *                object for which to update the address table count.
 *
 * @return none
 */
void scic_sds_unsolicited_frame_control_set_address_table_count(
   SCIC_SDS_UNSOLICITED_FRAME_CONTROL_T *uf_control
)
{
   uf_control->address_table.count = SCU_MIN_UF_TABLE_ENTRIES;
   while (
            (uf_control->address_table.count < uf_control->buffers.count)
         && (uf_control->address_table.count < SCU_ABSOLUTE_MAX_UNSOLICITED_FRAMES)
         )
   {
      uf_control->address_table.count <<= 1;
   }
}

/**
 * @brief This method will program the unsolicited frames (UFs) into
 *        the UF address table and construct the UF frame structure
 *        being modeled in the core.  It will handle the case where
 *        some of the UFs are not being used and thus should have
 *        entries programmed to zero in the address table.
 *
 * @param[in,out] uf_control This parameter specifies the unsolicted
 *                frame control object for which to construct the
 *                unsolicited frames objects.
 * @param[in]     uf_buffer_phys_address This parameter specifies the
 *                physical address for the first unsolicited frame
 *                buffer.
 * @param[in]     uf_buffer_virt_address This parameter specifies the
 *                virtual address for the first unsolicited frame
 *                buffer.
 * @param[in]     unused_uf_header_entries This parameter specifies
 *                the number of unused UF headers.  This value can
 *                be non-zero when there are a non-power of 2 number
 *                of unsolicited frames being supported.
 * @param[in]     used_uf_header_entries This parameter specifies
 *                the number of actually utilized UF headers.
 *
 * @return none
 */
static
void scic_sds_unsolicited_frame_control_construct_frames(
   SCIC_SDS_UNSOLICITED_FRAME_CONTROL_T *uf_control,
   SCI_PHYSICAL_ADDRESS                  uf_buffer_phys_address,
   POINTER_UINT                          uf_buffer_virt_address,
   U32                                   unused_uf_header_entries,
   U32                                   used_uf_header_entries
)
{
   U32                           index;
   SCIC_SDS_UNSOLICITED_FRAME_T *uf;

   // Program the unused buffers into the UF address table and the
   // controller's array of UFs.
   for (index = 0; index < unused_uf_header_entries; index++)
   {
      uf = &uf_control->buffers.array[index];

      sci_cb_make_physical_address(
         uf_control->address_table.array[index], 0, 0
      );
      uf->buffer = NULL;
      uf->header = &uf_control->headers.array[index];
      uf->state  = UNSOLICITED_FRAME_EMPTY;
   }

   // Program the actual used UF buffers into the UF address table and
   // the controller's array of UFs.
   for (index = unused_uf_header_entries;
        index < unused_uf_header_entries + used_uf_header_entries;
        index++)
   {
      uf = &uf_control->buffers.array[index];

      uf_control->address_table.array[index] = uf_buffer_phys_address;

      uf->buffer = (void*) uf_buffer_virt_address;
      uf->header = &uf_control->headers.array[index];
      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
      uf_buffer_virt_address += SCU_UNSOLICITED_FRAME_BUFFER_SIZE;
      sci_physical_address_add(
         uf_buffer_phys_address, SCU_UNSOLICITED_FRAME_BUFFER_SIZE
      );
   }
}

/**
 * @brief This method constructs the various members of the unsolicted
 *        frame control object (buffers, headers, address, table, etc).
 *
 * @param[in,out] uf_control This parameter specifies the unsolicited
 *                frame control object to construct.
 * @param[in]     mde This parameter specifies the memory descriptor
 *                from which to derive all of the address information
 *                needed to get the unsolicited frame functionality
 *                working.
 * @param[in]     controller This parameter specifies the controller
 *                object associated with the uf_control being constructed.
 *
 * @return none
 */
void scic_sds_unsolicited_frame_control_construct(
   SCIC_SDS_UNSOLICITED_FRAME_CONTROL_T *uf_control,
   SCI_PHYSICAL_MEMORY_DESCRIPTOR_T     *mde,
   SCIC_SDS_CONTROLLER_T                *controller
)
{
   U32  unused_uf_header_entries;
   U32  used_uf_header_entries;
   U32  used_uf_buffer_bytes;
   U32  unused_uf_header_bytes;
   U32  used_uf_header_bytes;
   SCI_PHYSICAL_ADDRESS  uf_buffer_phys_address;

   // Prepare all of the memory sizes for the UF headers, UF address
   // table, and UF buffers themselves.
   used_uf_buffer_bytes     = uf_control->buffers.count
                              * SCU_UNSOLICITED_FRAME_BUFFER_SIZE;
   unused_uf_header_entries = uf_control->address_table.count
                              - uf_control->buffers.count;
   used_uf_header_entries   = uf_control->buffers.count;
   unused_uf_header_bytes   = unused_uf_header_entries
                              * sizeof(SCU_UNSOLICITED_FRAME_HEADER_T);
   used_uf_header_bytes     = used_uf_header_entries
                              * sizeof(SCU_UNSOLICITED_FRAME_HEADER_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.
   uf_buffer_phys_address = mde->physical_address;

   // 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 = uf_buffer_phys_address;
   sci_physical_address_add(
      uf_control->headers.physical_address, used_uf_buffer_bytes);
   sci_physical_address_subtract(
      uf_control->headers.physical_address, unused_uf_header_bytes);

   uf_control->headers.array = (SCU_UNSOLICITED_FRAME_HEADER_T*)
      ((U8 *)mde->virtual_address + used_uf_buffer_bytes - unused_uf_header_bytes);

   // 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 = uf_buffer_phys_address;
   sci_physical_address_add(
      uf_control->address_table.physical_address, used_uf_buffer_bytes);
   sci_physical_address_add(
      uf_control->address_table.physical_address, used_uf_header_bytes);

   uf_control->address_table.array = (SCI_PHYSICAL_ADDRESS*)
      ((U8 *)mde->virtual_address + used_uf_buffer_bytes + used_uf_header_bytes);

   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.

   // If the user provided less then the maximum amount of memory,
   // then be sure that we programm the first entries in the UF
   // address table to NULL.
   scic_sds_unsolicited_frame_control_construct_frames(
      uf_control,
      uf_buffer_phys_address,
      (POINTER_UINT) mde->virtual_address,
      unused_uf_header_entries,
      used_uf_header_entries
   );
}

/**
 * @brief This method returns the frame header for the specified frame
 *        index.
 *
 * @param[in] uf_control
 * @param[in] frame_index
 * @param[out] frame_header
 *
 * @return SCI_STATUS
 */
SCI_STATUS scic_sds_unsolicited_frame_control_get_header(
   SCIC_SDS_UNSOLICITED_FRAME_CONTROL_T *uf_control,
   U32                                   frame_index,
   void                                **frame_header
)
{
   if (frame_index < uf_control->address_table.count)
   {
      // 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;
}

/**
 * @brief This method returns the frame buffer for the specified frame
 *        index.
 *
 * @param[in] uf_control
 * @param[in] frame_index
 * @param[out] frame_buffer
 *
 * @return SCI_STATUS
 */
SCI_STATUS scic_sds_unsolicited_frame_control_get_buffer(
   SCIC_SDS_UNSOLICITED_FRAME_CONTROL_T *uf_control,
   U32                                   frame_index,
   void                                **frame_buffer
)
{
   if (frame_index < uf_control->address_table.count)
   {
      *frame_buffer = uf_control->buffers.array[frame_index].buffer;

      return SCI_SUCCESS;
   }

   return SCI_FAILURE_INVALID_PARAMETER_VALUE;
}

/**
 * @brief 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.
 *
 * @param[in] uf_control This parameter specifies the UF control object
 * @param[in] frame_index This parameter specifies the frame index to
 *            attempt to release.
 *
 * @return This method returns an indication to the caller as to whether
 *         the unsolicited frame get pointer should be updated.
 * @retval TRUE This value indicates the unsolicited frame get pointer
 *         should be updated (i.e. write SCU_UFQGP_WRITE).
 * @retval FALSE This value indicates the get pointer should not be
 *         updated.
 */
BOOL scic_sds_unsolicited_frame_control_release_frame(
   SCIC_SDS_UNSOLICITED_FRAME_CONTROL_T *uf_control,
   U32                                   frame_index
)
{
   U32 frame_get;
   U32 frame_cycle;

   frame_get   = uf_control->get & (uf_control->address_table.count - 1);
   frame_cycle = uf_control->get & uf_control->address_table.count;

   // 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 (
            (
               (sci_cb_physical_address_lower(
                   uf_control->address_table.array[frame_get]) == 0)
            && (sci_cb_physical_address_upper(
                   uf_control->address_table.array[frame_get]) == 0)
            )
         && (frame_get < uf_control->address_table.count)
         )
   {
      frame_get++;
   }

   // The table has a NULL entry as it's last element.  This is
   // illegal.
   ASSERT(frame_get < uf_control->address_table.count);

   if (frame_index < uf_control->address_table.count)
   {
      uf_control->buffers.array[frame_index].state = UNSOLICITED_FRAME_RELEASED;

      // The frame index is equal to the current get pointer so we
      // can now free up all of the frame entries that
      if (frame_get == frame_index)
      {
         while (
                  uf_control->buffers.array[frame_get].state
               == UNSOLICITED_FRAME_RELEASED
               )
         {
            uf_control->buffers.array[frame_get].state = UNSOLICITED_FRAME_EMPTY;

            INCREMENT_QUEUE_GET(
               frame_get,
               frame_cycle,
               uf_control->address_table.count - 1,
               uf_control->address_table.count
            );
         }

         uf_control->get =
                  (SCU_UFQGP_GEN_BIT(ENABLE_BIT) | frame_cycle | frame_get);

         return TRUE;
      }
      else
      {
         // Frames remain in use until we advance the get pointer
         // so there is nothing we can do here
      }
   }

   return FALSE;
}