amd/amdkfd/kfd_pasid.c

0001 // SPDX-License-Identifier: GPL-2.0 OR MIT
0002 /*
0003  * Copyright 2014-2022 Advanced Micro Devices, Inc.
0004  *
0005  * Permission is hereby granted, free of charge, to any person obtaining a
0006  * copy of this software and associated documentation files (the "Software"),
0007  * to deal in the Software without restriction, including without limitation
0008  * the rights to use, copy, modify, merge, publish, distribute, sublicense,
0009  * and/or sell copies of the Software, and to permit persons to whom the
0010  * Software is furnished to do so, subject to the following conditions:
0011  *
0012  * The above copyright notice and this permission notice shall be included in
0013  * all copies or substantial portions of the Software.
0014  *
0015  * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
0016  * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
0017  * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT.  IN NO EVENT SHALL
0018  * THE COPYRIGHT HOLDER(S) OR AUTHOR(S) BE LIABLE FOR ANY CLAIM, DAMAGES OR
0019  * OTHER LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE,
0020  * ARISING FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR
0021  * OTHER DEALINGS IN THE SOFTWARE.
0022  */
0023
0024 #include <linux/types.h>
0025 #include "kfd_priv.h"
0026 #include "amdgpu_ids.h"
0027
0028 static unsigned int pasid_bits = 16;
0029 static bool pasids_allocated; /* = false */
0030
0031 bool kfd_set_pasid_limit(unsigned int new_limit)
0032 {
0033     if (new_limit < 2)
0034         return false;
0035
0036     if (new_limit < (1U << pasid_bits)) {
0037         if (pasids_allocated)
0038             /* We've already allocated user PASIDs, too late to
0039              * change the limit
0040              */
0041             return false;
0042
0043         while (new_limit < (1U << pasid_bits))
0044             pasid_bits--;
0045     }
0046
0047     return true;
0048 }
0049
0050 unsigned int kfd_get_pasid_limit(void)
0051 {
0052     return 1U << pasid_bits;
0053 }
0054
0055 u32 kfd_pasid_alloc(void)
0056 {
0057     int r = amdgpu_pasid_alloc(pasid_bits);
0058
0059     if (r > 0) {
0060         pasids_allocated = true;
0061         return r;
0062     }
0063
0064     return 0;
0065 }
0066
0067 void kfd_pasid_free(u32 pasid)
0068 {
0069     amdgpu_pasid_free(pasid);
0070 }