1 /*
2 * Copyright (c) 2021, Arm Limited. All rights reserved.
3 *
4 * SPDX-License-Identifier: BSD-3-Clause
5 */
6
7 #include <stddef.h>
8 #include <stdint.h>
9
10 #include <common/debug.h>
11 #include <common/fdt_wrappers.h>
12 #include <lib/fconf/fconf.h>
13 #include <lib/fconf/fconf_amu_getter.h>
14 #include <libfdt.h>
15
16 #include <plat/common/platform.h>
17
18 struct fconf_amu_config fconf_amu_config;
19 static struct amu_topology fconf_amu_topology_;
20
21 /*
22 * Populate the core-specific AMU structure with information retrieved from a
23 * device tree.
24 *
25 * Returns `0` on success, or a negative integer representing an error code.
26 */
fconf_populate_amu_cpu_amu(const void * fdt,int parent,struct amu_core * amu)27 static int fconf_populate_amu_cpu_amu(const void *fdt, int parent,
28 struct amu_core *amu)
29 {
30 int ret = 0;
31 int node = 0;
32
33 fdt_for_each_subnode(node, fdt, parent) {
34 const char *name;
35 const char *value;
36 int len;
37
38 uintptr_t idx = 0U;
39
40 name = fdt_get_name(fdt, node, &len);
41 if (strncmp(name, "counter@", 8) != 0) {
42 continue;
43 }
44
45 ret = fdt_get_reg_props_by_index(fdt, node, 0, &idx, NULL);
46 if (ret < 0) {
47 break;
48 }
49
50 value = fdt_getprop(fdt, node, "enable-at-el3", &len);
51 if ((value == NULL) && (len != -FDT_ERR_NOTFOUND)) {
52 break;
53 }
54
55 if (len != -FDT_ERR_NOTFOUND) {
56 amu->enable |= (1 << idx);
57 }
58 }
59
60 if ((node < 0) && (node != -FDT_ERR_NOTFOUND)) {
61 return node;
62 }
63
64 return ret;
65 }
66
67 /*
68 * Within a `cpu` node, attempt to dereference the `amu` property, and populate
69 * the AMU information for the core.
70 *
71 * Returns `0` on success, or a negative integer representing an error code.
72 */
fconf_populate_amu_cpu(const void * fdt,int node,uintptr_t mpidr)73 static int fconf_populate_amu_cpu(const void *fdt, int node, uintptr_t mpidr)
74 {
75 int ret;
76 int idx;
77
78 uint32_t amu_phandle;
79 struct amu_core *amu;
80
81 ret = fdt_read_uint32(fdt, node, "amu", &amu_phandle);
82 if (ret < 0) {
83 if (ret == -FDT_ERR_NOTFOUND) {
84 ret = 0;
85 }
86
87 return ret;
88 }
89
90 node = fdt_node_offset_by_phandle(fdt, amu_phandle);
91 if (node < 0) {
92 return node;
93 }
94
95 idx = plat_core_pos_by_mpidr(mpidr);
96 if (idx < 0) {
97 return -FDT_ERR_BADVALUE;
98 }
99
100 amu = &fconf_amu_topology_.cores[idx];
101
102 return fconf_populate_amu_cpu_amu(fdt, node, amu);
103 }
104
105 /*
106 * Populates the global `amu_topology` structure based on what's described by
107 * the hardware configuration device tree blob.
108 *
109 * The device tree is expected to provide an `amu` property for each `cpu` node,
110 * like so:
111 *
112 * cpu@0 {
113 * amu = <&cpu0_amu>;
114 * };
115 *
116 * amus {
117 * cpu0_amu: amu-0 {
118 * counters {
119 * #address-cells = <2>;
120 * #size-cells = <0>;
121 *
122 * counter@x,y {
123 * reg = <x y>; // Group x, counter y
124 * };
125 * };
126 * };
127 * };
128 */
fconf_populate_amu(uintptr_t config)129 static int fconf_populate_amu(uintptr_t config)
130 {
131 int ret = fdtw_for_each_cpu(
132 (const void *)config, fconf_populate_amu_cpu);
133 if (ret == 0) {
134 fconf_amu_config.topology = &fconf_amu_topology_;
135 } else {
136 ERROR("FCONF: failed to parse AMU information: %d\n", ret);
137 }
138
139 return ret;
140 }
141
142 FCONF_REGISTER_POPULATOR(HW_CONFIG, amu, fconf_populate_amu);
143