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