drivers/misc/habanalabs/asid.c

   1 // SPDX-License-Identifier: GPL-2.0
   2
   3 /*
   4  * Copyright 2016-2019 HabanaLabs, Ltd.
   5  * All Rights Reserved.
   6  */
   7
   8 #include "habanalabs.h"
   9
  10 #include <linux/slab.h>
  11
  12 int hl_asid_init(struct hl_device *hdev)
  13 {
  14         hdev->asid_bitmap = kcalloc(BITS_TO_LONGS(hdev->asic_prop.max_asid),
  15                                         sizeof(*hdev->asid_bitmap), GFP_KERNEL);
  16         if (!hdev->asid_bitmap)
  17                 return -ENOMEM;
  18
  19         mutex_init(&hdev->asid_mutex);
  20
  21         /* ASID 0 is reserved for the kernel driver and device CPU */
  22         set_bit(0, hdev->asid_bitmap);
  23
  24         return 0;
  25 }
  26
  27 void hl_asid_fini(struct hl_device *hdev)
  28 {
  29         mutex_destroy(&hdev->asid_mutex);
  30         kfree(hdev->asid_bitmap);
  31 }
  32
  33 unsigned long hl_asid_alloc(struct hl_device *hdev)
  34 {
  35         unsigned long found;
  36
  37         mutex_lock(&hdev->asid_mutex);
  38
  39         found = find_first_zero_bit(hdev->asid_bitmap,
  40                                         hdev->asic_prop.max_asid);
  41         if (found == hdev->asic_prop.max_asid)
  42                 found = 0;
  43         else
  44                 set_bit(found, hdev->asid_bitmap);
  45
  46         mutex_unlock(&hdev->asid_mutex);
  47
  48         return found;
  49 }
  50
  51 void hl_asid_free(struct hl_device *hdev, unsigned long asid)
  52 {
  53         if (WARN((asid == 0 || asid >= hdev->asic_prop.max_asid),
  54                                                 "Invalid ASID %lu", asid))
  55                 return;
  56         clear_bit(asid, hdev->asid_bitmap);
  57 }