LXR linux/drivers/gpu/drm/amd/amdkfd/kfd

   1/*
   2 * Copyright 2014 Advanced Micro Devices, Inc.
   3 *
   4 * Permission is hereby granted, free of charge, to any person obtaining a
   5 * copy of this software and associated documentation files (the "Software"),
   6 * to deal in the Software without restriction, including without limitation
   7 * the rights to use, copy, modify, merge, publish, distribute, sublicense,
   8 * and/or sell copies of the Software, and to permit persons to whom the
   9 * Software is furnished to do so, subject to the following conditions:
  10 *
  11 * The above copyright notice and this permission notice shall be included in
  12 * all copies or substantial portions of the Software.
  13 *
  14 * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
  15 * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
  16 * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT.  IN NO EVENT SHALL
  17 * THE COPYRIGHT HOLDER(S) OR AUTHOR(S) BE LIABLE FOR ANY CLAIM, DAMAGES OR
  18 * OTHER LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE,
  19 * ARISING FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR
  20 * OTHER DEALINGS IN THE SOFTWARE.
  21 */
  22
  23#include <linux/slab.h>
  24#include <linux/types.h>
  25#include "kfd_priv.h"
  26
  27static unsigned long *pasid_bitmap;
  28static unsigned int pasid_limit;
  29static DEFINE_MUTEX(pasid_mutex);
  30
  31int kfd_pasid_init(void)
  32{
  33        pasid_limit = KFD_MAX_NUM_OF_PROCESSES;
  34
  35        pasid_bitmap = kcalloc(BITS_TO_LONGS(pasid_limit), sizeof(long), GFP_KERNEL);
  36        if (!pasid_bitmap)
  37                return -ENOMEM;
  38
  39        set_bit(0, pasid_bitmap); /* PASID 0 is reserved. */
  40
  41        return 0;
  42}
  43
  44void kfd_pasid_exit(void)
  45{
  46        kfree(pasid_bitmap);
  47}
  48
  49bool kfd_set_pasid_limit(unsigned int new_limit)
  50{
  51        if (new_limit < pasid_limit) {
  52                bool ok;
  53
  54                mutex_lock(&pasid_mutex);
  55
  56                /* ensure that no pasids >= new_limit are in-use */
  57                ok = (find_next_bit(pasid_bitmap, pasid_limit, new_limit) ==
  58                                                                pasid_limit);
  59                if (ok)
  60                        pasid_limit = new_limit;
  61
  62                mutex_unlock(&pasid_mutex);
  63
  64                return ok;
  65        }
  66
  67        return true;
  68}
  69
  70inline unsigned int kfd_get_pasid_limit(void)
  71{
  72        return pasid_limit;
  73}
  74
  75unsigned int kfd_pasid_alloc(void)
  76{
  77        unsigned int found;
  78
  79        mutex_lock(&pasid_mutex);
  80
  81        found = find_first_zero_bit(pasid_bitmap, pasid_limit);
  82        if (found == pasid_limit)
  83                found = 0;
  84        else
  85                set_bit(found, pasid_bitmap);
  86
  87        mutex_unlock(&pasid_mutex);
  88
  89        return found;
  90}
  91
  92void kfd_pasid_free(unsigned int pasid)
  93{
  94        BUG_ON(pasid == 0 || pasid >= pasid_limit);
  95        clear_bit(pasid, pasid_bitmap);
  96}
  97