1 /* $NetBSD: vmid.c,v 1.2 2021/12/18 23:45:08 riastradh Exp $ */
2
3 /*
4 * Copyright 2019 Advanced Micro Devices, Inc.
5 *
6 * Permission is hereby granted, free of charge, to any person obtaining a
7 * copy of this software and associated documentation files (the "Software"),
8 * to deal in the Software without restriction, including without limitation
9 * the rights to use, copy, modify, merge, publish, distribute, sublicense,
10 * and/or sell copies of the Software, and to permit persons to whom the
11 * Software is furnished to do so, subject to the following conditions:
12 *
13 * The above copyright notice and this permission notice shall be included in
14 * all copies or substantial portions of the Software.
15 *
16 * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
17 * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
18 * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL
19 * THE COPYRIGHT HOLDER(S) OR AUTHOR(S) BE LIABLE FOR ANY CLAIM, DAMAGES OR
20 * OTHER LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE,
21 * ARISING FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR
22 * OTHER DEALINGS IN THE SOFTWARE.
23 *
24 * Authors: AMD
25 *
26 */
27
28 #include <sys/cdefs.h>
29 __KERNEL_RCSID(0, "$NetBSD: vmid.c,v 1.2 2021/12/18 23:45:08 riastradh Exp $");
30
31 #include "mod_vmid.h"
32
33 struct core_vmid {
34 struct mod_vmid public;
35 struct dc *dc;
36
37 unsigned int num_vmid;
38 unsigned int num_vmids_available;
39 uint64_t ptb_assigned_to_vmid[MAX_VMID];
40 struct dc_virtual_addr_space_config base_config;
41 };
42
43 #define MOD_VMID_TO_CORE(mod_vmid)\
44 container_of(mod_vmid, struct core_vmid, public)
45
add_ptb_to_table(struct core_vmid * core_vmid,unsigned int vmid,uint64_t ptb)46 static void add_ptb_to_table(struct core_vmid *core_vmid, unsigned int vmid, uint64_t ptb)
47 {
48 core_vmid->ptb_assigned_to_vmid[vmid] = ptb;
49 core_vmid->num_vmids_available--;
50 }
51
clear_entry_from_vmid_table(struct core_vmid * core_vmid,unsigned int vmid)52 static void clear_entry_from_vmid_table(struct core_vmid *core_vmid, unsigned int vmid)
53 {
54 core_vmid->ptb_assigned_to_vmid[vmid] = 0;
55 core_vmid->num_vmids_available++;
56 }
57
evict_vmids(struct core_vmid * core_vmid)58 static void evict_vmids(struct core_vmid *core_vmid)
59 {
60 int i;
61 uint16_t ord = dc_get_vmid_use_vector(core_vmid->dc);
62
63 // At this point any positions with value 0 are unused vmids, evict them
64 for (i = 1; i < core_vmid->num_vmid; i++) {
65 if (ord & (1u << i))
66 clear_entry_from_vmid_table(core_vmid, i);
67 }
68 }
69
70 // Return value of -1 indicates vmid table unitialized or ptb dne in the table
get_existing_vmid_for_ptb(struct core_vmid * core_vmid,uint64_t ptb)71 static int get_existing_vmid_for_ptb(struct core_vmid *core_vmid, uint64_t ptb)
72 {
73 int i;
74
75 for (i = 0; i < core_vmid->num_vmid; i++) {
76 if (core_vmid->ptb_assigned_to_vmid[i] == ptb)
77 return i;
78 }
79
80 return -1;
81 }
82
83 // Expected to be called only when there's an available vmid
get_next_available_vmid(struct core_vmid * core_vmid)84 static int get_next_available_vmid(struct core_vmid *core_vmid)
85 {
86 int i;
87
88 for (i = 1; i < core_vmid->num_vmid; i++) {
89 if (core_vmid->ptb_assigned_to_vmid[i] == 0)
90 return i;
91 }
92
93 return -1;
94 }
95
mod_vmid_get_for_ptb(struct mod_vmid * mod_vmid,uint64_t ptb)96 uint8_t mod_vmid_get_for_ptb(struct mod_vmid *mod_vmid, uint64_t ptb)
97 {
98 struct core_vmid *core_vmid = MOD_VMID_TO_CORE(mod_vmid);
99 unsigned int vmid = 0;
100
101 // Physical address gets vmid 0
102 if (ptb == 0)
103 return 0;
104
105 vmid = get_existing_vmid_for_ptb(core_vmid, ptb);
106
107 if (vmid == -1) {
108 struct dc_virtual_addr_space_config va_config = core_vmid->base_config;
109
110 va_config.page_table_base_addr = ptb;
111
112 if (core_vmid->num_vmids_available == 0)
113 evict_vmids(core_vmid);
114
115 vmid = get_next_available_vmid(core_vmid);
116 add_ptb_to_table(core_vmid, vmid, ptb);
117
118 dc_setup_vm_context(core_vmid->dc, &va_config, vmid);
119 }
120
121 return vmid;
122 }
123
mod_vmid_reset(struct mod_vmid * mod_vmid)124 void mod_vmid_reset(struct mod_vmid *mod_vmid)
125 {
126 struct core_vmid *core_vmid = MOD_VMID_TO_CORE(mod_vmid);
127
128 core_vmid->num_vmids_available = core_vmid->num_vmid - 1;
129 memset(core_vmid->ptb_assigned_to_vmid, 0, sizeof(core_vmid->ptb_assigned_to_vmid[0]) * MAX_VMID);
130 }
131
mod_vmid_create(struct dc * dc,unsigned int num_vmid,struct dc_virtual_addr_space_config * va_config)132 struct mod_vmid *mod_vmid_create(
133 struct dc *dc,
134 unsigned int num_vmid,
135 struct dc_virtual_addr_space_config *va_config)
136 {
137 struct core_vmid *core_vmid;
138
139 if (num_vmid <= 1)
140 goto fail_no_vm_ctx;
141
142 if (dc == NULL)
143 goto fail_dc_null;
144
145 core_vmid = kzalloc(sizeof(struct core_vmid), GFP_KERNEL);
146
147 if (core_vmid == NULL)
148 goto fail_alloc_context;
149
150 core_vmid->dc = dc;
151 core_vmid->num_vmid = num_vmid;
152 core_vmid->num_vmids_available = num_vmid - 1;
153 core_vmid->base_config = *va_config;
154
155 memset(core_vmid->ptb_assigned_to_vmid, 0, sizeof(core_vmid->ptb_assigned_to_vmid[0]) * MAX_VMID);
156
157 return &core_vmid->public;
158
159 fail_no_vm_ctx:
160 fail_alloc_context:
161 fail_dc_null:
162 return NULL;
163 }
164
mod_vmid_destroy(struct mod_vmid * mod_vmid)165 void mod_vmid_destroy(struct mod_vmid *mod_vmid)
166 {
167 if (mod_vmid != NULL) {
168 struct core_vmid *core_vmid = MOD_VMID_TO_CORE(mod_vmid);
169
170 kfree(core_vmid);
171 }
172 }
173