alistair23-linux/drivers/gpu/drm/amd/amdkfd/kfd_pasid.c
Oded Gabbay b8cbab042c drm/amdkfd: Allow user to limit only queues per device
This patch replaces the two current amdkfd module parameters with a new one.

The current parameters that are being replaced are:

- Maximum number of HSA processes
- Maximum number of queues per process

The new parameter that replaces them is called "Maximum queues per device"

This replacement achieves two goals:

- Allows the user to have as many HSA processes as it wants (until
  a maximum of 512 HSA processes in Kaveri).

- Removes the limitation the user had on maximum number of queues per HSA
  process. E.g. the user can now have processes which only have one queue and
  other processes which have hundreds of queues, while before the user
  couldn't have more than 128 queues per process (as default).

The default value of the new parameter is 4096 (32 * 128, which were the
defaults of the old parameters). There is almost no additional GART memory
required for the default case. As a reminder, this amount of queues requires a
little bit below 4MB of GART memory.

v2:
In addition, This patch defines a new counter for queues accounting in the DQM
structure. This is done because the current counter only counts active queues
which allows the user to create more queues than the
max_num_of_queues_per_device module parameter allows.

However, we need the current counter for the runlist packet build process, so
the solution is to have a dedicated counter for this accounting.

Signed-off-by: Oded Gabbay <oded.gabbay@amd.com>
Reviewed-by: Ben Goz <ben.goz@amd.com>
2015-01-18 13:18:01 +02:00

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
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* ARISING FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR
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*/
#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);
}