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 
28 struct 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 
41 static 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 
49 static 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 
57 static void evict_vmids(struct core_vmid *core_vmid)
58 {
59 	int i;
60 	uint16_t ord = dc_get_vmid_use_vector(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, i);
66 	}
67 }
68 
69 // Return value of -1 indicates vmid table uninitialized or ptb dne in the table
70 static 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
83 static 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 
95 uint8_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(core_vmid->dc, &va_config, vmid);
119 		} else
120 			ASSERT(0);
121 	}
122 
123 	return vmid;
124 }
125 
126 void 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 
134 struct 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 
161 fail_no_vm_ctx:
162 fail_alloc_context:
163 fail_dc_null:
164 	return NULL;
165 }
166 
167 void 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(core_vmid);
173 	}
174 }
175