drivers/gpu/drm/amd/amdkfd/kfd_pasid.c

   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/types.h>
  24 #include "kfd_priv.h"
  25 #include "amdgpu_ids.h"
  26
  27 static unsigned int pasid_bits = 16;
  28 static bool pasids_allocated; /* = false */
  29
  30 bool kfd_set_pasid_limit(unsigned int new_limit)
  31 {
  32         if (new_limit < 2)
  33                 return false;
  34
  35         if (new_limit < (1U << pasid_bits)) {
  36                 if (pasids_allocated)
  37                         /* We've already allocated user PASIDs, too late to
  38                          * change the limit
  39                          */
  40                         return false;
  41
  42                 while (new_limit < (1U << pasid_bits))
  43                         pasid_bits--;
  44         }
  45
  46         return true;
  47 }
  48
  49 unsigned int kfd_get_pasid_limit(void)
  50 {
  51         return 1U << pasid_bits;
  52 }
  53
  54 u32 kfd_pasid_alloc(void)
  55 {
  56         int r = amdgpu_pasid_alloc(pasid_bits);
  57
  58         if (r > 0) {
  59                 pasids_allocated = true;
  60                 return r;
  61         }
  62
  63         return 0;
  64 }
  65
  66 void kfd_pasid_free(u32 pasid)
  67 {
  68         amdgpu_pasid_free(pasid);
  69 }