OpenCloudOS-Kernel/drivers/gpu/drm/amd/amdkfd/kfd_pasid.c

97 lines
2.4 KiB
C

/*
* Copyright 2014 Advanced Micro Devices, Inc.
*
* Permission is hereby granted, free of charge, to any person obtaining a
* copy of this software and associated documentation files (the "Software"),
* to deal in the Software without restriction, including without limitation
* the rights to use, copy, modify, merge, publish, distribute, sublicense,
* and/or sell copies of the Software, and to permit persons to whom the
* Software is furnished to do so, subject to the following conditions:
*
* The above copyright notice and this permission notice shall be included in
* all copies or substantial portions of the Software.
*
* THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
* IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
* FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL
* THE COPYRIGHT HOLDER(S) OR AUTHOR(S) BE LIABLE FOR ANY CLAIM, DAMAGES OR
* OTHER LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE,
* ARISING FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR
* OTHER DEALINGS IN THE SOFTWARE.
*/
#include <linux/slab.h>
#include <linux/types.h>
#include "kfd_priv.h"
static unsigned long *pasid_bitmap;
static unsigned int pasid_limit;
static DEFINE_MUTEX(pasid_mutex);
int kfd_pasid_init(void)
{
pasid_limit = KFD_MAX_NUM_OF_PROCESSES;
pasid_bitmap = kcalloc(BITS_TO_LONGS(pasid_limit), sizeof(long), GFP_KERNEL);
if (!pasid_bitmap)
return -ENOMEM;
set_bit(0, pasid_bitmap); /* PASID 0 is reserved. */
return 0;
}
void kfd_pasid_exit(void)
{
kfree(pasid_bitmap);
}
bool kfd_set_pasid_limit(unsigned int new_limit)
{
if (new_limit < pasid_limit) {
bool ok;
mutex_lock(&pasid_mutex);
/* ensure that no pasids >= new_limit are in-use */
ok = (find_next_bit(pasid_bitmap, pasid_limit, new_limit) ==
pasid_limit);
if (ok)
pasid_limit = new_limit;
mutex_unlock(&pasid_mutex);
return ok;
}
return true;
}
inline unsigned int kfd_get_pasid_limit(void)
{
return pasid_limit;
}
unsigned int kfd_pasid_alloc(void)
{
unsigned int found;
mutex_lock(&pasid_mutex);
found = find_first_zero_bit(pasid_bitmap, pasid_limit);
if (found == pasid_limit)
found = 0;
else
set_bit(found, pasid_bitmap);
mutex_unlock(&pasid_mutex);
return found;
}
void kfd_pasid_free(unsigned int pasid)
{
BUG_ON(pasid == 0 || pasid >= pasid_limit);
clear_bit(pasid, pasid_bitmap);
}