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(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
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(core_vmid->dc, &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(core_vmid);
173	}
174}
175