FreeBSD/Linux Kernel Cross Reference
sys/dev/ice/ice_resmgr.c

     /* SPDX-License-Identifier: BSD-3-Clause */
     /*  Copyright (c) 2021, Intel Corporation
      *  All rights reserved.
      *
      *  Redistribution and use in source and binary forms, with or without
      *  modification, are permitted provided that the following conditions are met:
      *
      *   1. Redistributions of source code must retain the above copyright notice,
      *      this list of conditions and the following disclaimer.
     *
     *   2. 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.
     *
     *   3. Neither the name of the 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.
     */
    /*$FreeBSD$*/
    
    /**
     * @file ice_resmgr.c
     * @brief Resource allocation manager
     *
     * Manage device resource allocations for a PF, including assigning queues to
     * VSIs, or managing interrupt allocations across the PF.
     *
     * It can handle contiguous and scattered resource allocations, and upon
     * assigning them, will fill in the mapping array with a map of
     * resource IDs to PF-space resource indices.
     */
    
    #include "ice_resmgr.h"
    
    /**
     * @var M_ICE_RESMGR
     * @brief PF resource manager allocation type
     *
     * malloc(9) allocation type used by the resource manager code.
     */
    MALLOC_DEFINE(M_ICE_RESMGR, "ice-resmgr", "Intel(R) 100Gb Network Driver resmgr allocations");
    
    /*
     * Public resource manager allocation functions
     */
    
    /**
     * ice_resmgr_init - Initialize a resource manager structure
     * @resmgr: structure to track the resource manager state
     * @num_res: the maximum number of resources it can assign
     *
     * Initialize the state of a resource manager structure, allocating space to
     * assign up to the requested number of resources. Uses bit strings to track
     * which resources have been assigned. This type of resmgr is intended to be
     * used for tracking LAN queue assignments between VSIs.
     */
    int
    ice_resmgr_init(struct ice_resmgr *resmgr, u16 num_res)
    {
            resmgr->resources = bit_alloc(num_res, M_ICE_RESMGR, M_NOWAIT);
            if (resmgr->resources == NULL)
                    return (ENOMEM);
    
            resmgr->num_res = num_res;
            resmgr->contig_only = false;
            return (0);
    }
    
    /**
     * ice_resmgr_init_contig_only - Initialize a resource manager structure
     * @resmgr: structure to track the resource manager state
     * @num_res: the maximum number of resources it can assign
     *
     * Functions similarly to ice_resmgr_init(), but the resulting resmgr structure
     * will only allow contiguous allocations. This type of resmgr is intended to
     * be used with tracking device MSI-X interrupt allocations.
     */
    int
    ice_resmgr_init_contig_only(struct ice_resmgr *resmgr, u16 num_res)
    {
            int error;
    
            error = ice_resmgr_init(resmgr, num_res);
            if (error)
                    return (error);
    
            resmgr->contig_only = true;
           return (0);
   }
   
   /**
    * ice_resmgr_destroy - Deallocate memory associated with a resource manager
    * @resmgr: resource manager structure
    *
    * De-allocates the bit string associated with this resource manager. It is
    * expected that this function will not be called until all of the assigned
    * resources have been released.
    */
   void
   ice_resmgr_destroy(struct ice_resmgr *resmgr)
   {
           if (resmgr->resources != NULL) {
   #ifdef INVARIANTS
                   int set;
   
                   bit_count(resmgr->resources, 0, resmgr->num_res, &set);
                   MPASS(set == 0);
   #endif
   
                   free(resmgr->resources, M_ICE_RESMGR);
                   resmgr->resources = NULL;
           }
           resmgr->num_res = 0;
   }
   
   /*
    * Resource allocation functions
    */
   
   /**
    * ice_resmgr_assign_contiguous - Assign contiguous mapping of resources
    * @resmgr: resource manager structure
    * @idx: memory to store mapping, at least num_res wide
    * @num_res: the number of resources to assign
    *
    * Assign num_res number of contiguous resources into the idx mapping. On
    * success, idx will be updated to map each index to a PF resource.
    *
    * This function guarantees that the resource mapping will be contiguous, and
    * will fail if that is not possible.
    */
   int
   ice_resmgr_assign_contiguous(struct ice_resmgr *resmgr, u16 *idx, u16 num_res)
   {
           int start, i;
   
           bit_ffc_area(resmgr->resources, resmgr->num_res, num_res, &start);
           if (start < 0)
                   return (ENOSPC);
   
           /* Set each bit and update the index array */
           for (i = 0; i < num_res; i++) {
                   bit_set(resmgr->resources, start + i);
                   idx[i] = start + i;
           }
   
           return (0);
   }
   
   /**
    * ice_resmgr_assign_scattered - Assign possibly scattered resources
    * @resmgr: the resource manager structure
    * @idx: memory to store associated resource mapping, at least num_res wide
    * @num_res: the number of resources to assign
    *
    * Assign num_res number of resources into the idx_mapping. On success, idx
    * will be updated to map each index to a PF-space resource.
    *
    * Queues may be allocated non-contiguously, and this function requires that
    * num_res be less than the ICE_MAX_SCATTERED_QUEUES due to hardware
    * limitations on scattered queue assignment.
    */
   int
   ice_resmgr_assign_scattered(struct ice_resmgr *resmgr, u16 *idx, u16 num_res)
   {
           int index = 0, i;
   
           /* Scattered allocations won't work if they weren't allowed at resmgr
            * creation time.
            */
           if (resmgr->contig_only)
                   return (EPERM);
   
           /* Hardware can only support a limited total of scattered queues for
            * a single VSI
            */
           if (num_res > ICE_MAX_SCATTERED_QUEUES)
                   return (EOPNOTSUPP);
   
           for (i = 0; i < num_res; i++) {
                   bit_ffc_at(resmgr->resources, index, resmgr->num_res, &index);
                   if (index < 0)
                           goto err_no_space;
   
                   bit_set(resmgr->resources, index);
                   idx[i] = index;
           }
           return (0);
   
   err_no_space:
           /* Release any resources we did assign up to this point. */
           ice_resmgr_release_map(resmgr, idx, i);
           return (ENOSPC);
   }
   
   /**
    * ice_resmgr_release_map - Release previously assigned resource mapping
    * @resmgr: the resource manager structure
    * @idx: previously assigned resource mapping
    * @num_res: number of resources in the mapping
    *
    * Clears the assignment of each resource in the provided resource index. Updates
    * the idx to indicate that each of the virtual indexes have invalid resource
    * mappings by assigning them to ICE_INVALID_RES_IDX.
    */
   void
   ice_resmgr_release_map(struct ice_resmgr *resmgr, u16 *idx, u16 num_res)
   {
           int i;
   
           for (i = 0; i < num_res; i++) {
                   if (idx[i] < resmgr->num_res)
                           bit_clear(resmgr->resources, idx[i]);
                   idx[i] = ICE_INVALID_RES_IDX;
           }
   }

Cache object: 18ebd29ba7906f0911b3d2df28b008f2