1/*
2 * Copyright 2019 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 * Authors: AMD
23 *
24 */
25
26#include "mod_vmid.h"
27
28struct core_vmid {
29 struct mod_vmid public;
30 struct dc *dc;
31
32 unsigned int num_vmid;
33 unsigned int num_vmids_available;
34 uint64_t ptb_assigned_to_vmid[MAX_VMID];
35 struct dc_virtual_addr_space_config base_config;
36};
37
38#define MOD_VMID_TO_CORE(mod_vmid)\
39 container_of(mod_vmid, struct core_vmid, public)
40
41static void add_ptb_to_table(struct core_vmid *core_vmid, unsigned int vmid, uint64_t ptb)
42{
43 if (vmid < MAX_VMID) {
44 core_vmid->ptb_assigned_to_vmid[vmid] = ptb;
45 core_vmid->num_vmids_available--;
46 }
47}
48
49static void clear_entry_from_vmid_table(struct core_vmid *core_vmid, unsigned int vmid)
50{
51 if (vmid < MAX_VMID) {
52 core_vmid->ptb_assigned_to_vmid[vmid] = 0;
53 core_vmid->num_vmids_available++;
54 }
55}
56
57static void evict_vmids(struct core_vmid *core_vmid)
58{
59 int i;
60 uint16_t ord = dc_get_vmid_use_vector(dc: core_vmid->dc);
61
62 // At this point any positions with value 0 are unused vmids, evict them
63 for (i = 1; i < core_vmid->num_vmid; i++) {
64 if (!(ord & (1u << i)))
65 clear_entry_from_vmid_table(core_vmid, vmid: i);
66 }
67}
68
69// Return value of -1 indicates vmid table uninitialized or ptb dne in the table
70static int get_existing_vmid_for_ptb(struct core_vmid *core_vmid, uint64_t ptb)
71{
72 int i;
73
74 for (i = 0; i < core_vmid->num_vmid; i++) {
75 if (core_vmid->ptb_assigned_to_vmid[i] == ptb)
76 return i;
77 }
78
79 return -1;
80}
81
82// Expected to be called only when there's an available vmid
83static int get_next_available_vmid(struct core_vmid *core_vmid)
84{
85 int i;
86
87 for (i = 1; i < core_vmid->num_vmid; i++) {
88 if (core_vmid->ptb_assigned_to_vmid[i] == 0)
89 return i;
90 }
91
92 return -1;
93}
94
95uint8_t mod_vmid_get_for_ptb(struct mod_vmid *mod_vmid, uint64_t ptb)
96{
97 struct core_vmid *core_vmid = MOD_VMID_TO_CORE(mod_vmid);
98 int vmid = 0;
99
100 // Physical address gets vmid 0
101 if (ptb == 0)
102 return 0;
103
104 vmid = get_existing_vmid_for_ptb(core_vmid, ptb);
105
106 if (vmid == -1) {
107 struct dc_virtual_addr_space_config va_config = core_vmid->base_config;
108
109 va_config.page_table_base_addr = ptb;
110
111 if (core_vmid->num_vmids_available == 0)
112 evict_vmids(core_vmid);
113
114 vmid = get_next_available_vmid(core_vmid);
115 if (vmid != -1) {
116 add_ptb_to_table(core_vmid, vmid, ptb);
117
118 dc_setup_vm_context(dc: core_vmid->dc, va_config: &va_config, vmid);
119 } else
120 ASSERT(0);
121 }
122
123 return vmid;
124}
125
126void mod_vmid_reset(struct mod_vmid *mod_vmid)
127{
128 struct core_vmid *core_vmid = MOD_VMID_TO_CORE(mod_vmid);
129
130 core_vmid->num_vmids_available = core_vmid->num_vmid - 1;
131 memset(core_vmid->ptb_assigned_to_vmid, 0, sizeof(core_vmid->ptb_assigned_to_vmid[0]) * MAX_VMID);
132}
133
134struct mod_vmid *mod_vmid_create(
135 struct dc *dc,
136 unsigned int num_vmid,
137 struct dc_virtual_addr_space_config *va_config)
138{
139 struct core_vmid *core_vmid;
140
141 if (num_vmid <= 1)
142 goto fail_no_vm_ctx;
143
144 if (dc == NULL)
145 goto fail_dc_null;
146
147 core_vmid = kzalloc(sizeof(struct core_vmid), GFP_KERNEL);
148
149 if (core_vmid == NULL)
150 goto fail_alloc_context;
151
152 core_vmid->dc = dc;
153 core_vmid->num_vmid = num_vmid;
154 core_vmid->num_vmids_available = num_vmid - 1;
155 core_vmid->base_config = *va_config;
156
157 memset(core_vmid->ptb_assigned_to_vmid, 0, sizeof(core_vmid->ptb_assigned_to_vmid[0]) * MAX_VMID);
158
159 return &core_vmid->public;
160
161fail_no_vm_ctx:
162fail_alloc_context:
163fail_dc_null:
164 return NULL;
165}
166
167void mod_vmid_destroy(struct mod_vmid *mod_vmid)
168{
169 if (mod_vmid != NULL) {
170 struct core_vmid *core_vmid = MOD_VMID_TO_CORE(mod_vmid);
171
172 kfree(objp: core_vmid);
173 }
174}
175

source code of linux/drivers/gpu/drm/amd/display/modules/vmid/vmid.c