1 /* SPDX-License-Identifier: GPL-2.0-only */
2
3 #include <assert.h>
4 #include <bootstate.h>
5 #include <cbfs.h>
6 #include <console/console.h>
7 #include <device/device.h>
8 #include <ec/google/chromeec/ec.h>
9 #include <fw_config.h>
10 #include <inttypes.h>
11 #include <lib.h>
12 #include <drivers/vpd/vpd.h>
13
fw_config_get(void)14 uint64_t fw_config_get(void)
15 {
16 static uint64_t fw_config_value;
17 static bool fw_config_value_initialized;
18
19 /* Nothing to prepare if setup is already done. */
20 if (fw_config_value_initialized)
21 return fw_config_value;
22 fw_config_value_initialized = true;
23 fw_config_value = UNDEFINED_FW_CONFIG;
24
25 /* Read the value from EC CBI. */
26 if (CONFIG(FW_CONFIG_SOURCE_CHROMEEC_CBI)) {
27 if (google_chromeec_cbi_get_fw_config(&fw_config_value))
28 printk(BIOS_WARNING, "%s: Could not get fw_config from CBI\n",
29 __func__);
30 else
31 printk(BIOS_INFO, "FW_CONFIG value from CBI is 0x%" PRIx64 "\n",
32 fw_config_value);
33 }
34
35 /* Look in CBFS to allow override of value. */
36 if (CONFIG(FW_CONFIG_SOURCE_CBFS) && fw_config_value == UNDEFINED_FW_CONFIG) {
37 if (cbfs_load(CONFIG_CBFS_PREFIX "/fw_config", &fw_config_value,
38 sizeof(fw_config_value)) != sizeof(fw_config_value))
39 printk(BIOS_WARNING, "%s: Could not get fw_config from CBFS\n",
40 __func__);
41 else
42 printk(BIOS_INFO, "FW_CONFIG value from CBFS is 0x%" PRIx64 "\n",
43 fw_config_value);
44 }
45
46 if (CONFIG(FW_CONFIG_SOURCE_VPD) && fw_config_value == UNDEFINED_FW_CONFIG) {
47 int vpd_value;
48 if (vpd_get_int("fw_config", VPD_RW_THEN_RO, &vpd_value)) {
49 fw_config_value = vpd_value;
50 printk(BIOS_INFO, "FW_CONFIG value from VPD is 0x%" PRIx64 "\n",
51 fw_config_value);
52 } else
53 printk(BIOS_WARNING, "%s: Could not get fw_config from vpd\n",
54 __func__);
55 }
56
57 return fw_config_value;
58 }
59
fw_config_get_field(const struct fw_config_field * field)60 uint64_t fw_config_get_field(const struct fw_config_field *field)
61 {
62 /* If fw_config is not provisioned, then there is nothing to get. */
63 if (!fw_config_is_provisioned())
64 return UNDEFINED_FW_CONFIG;
65
66 int shift = __ffs64(field->mask);
67 const uint64_t value = (fw_config_get() & field->mask) >> shift;
68
69 printk(BIOS_INFO, "fw_config get field name=%s, mask=0x%" PRIx64 ", shift=%d, value=0x%"
70 PRIx64 "\n", field->field_name, field->mask, shift, value);
71
72 return value;
73 }
74
fw_config_probe(const struct fw_config * match)75 bool fw_config_probe(const struct fw_config *match)
76 {
77 /* If fw_config is not provisioned, then there is nothing to match. */
78 if (!fw_config_is_provisioned())
79 return false;
80
81 /* Compare to system value. */
82 if ((fw_config_get() & match->mask) == match->value) {
83 if (match->field_name && match->option_name)
84 printk(BIOS_INFO, "fw_config match found: %s=%s\n", match->field_name,
85 match->option_name);
86 else
87 printk(BIOS_INFO, "fw_config match found: mask=0x%" PRIx64 " value=0x%"
88 PRIx64 "\n",
89 match->mask, match->value);
90 return true;
91 }
92
93 return false;
94 }
95
fw_config_probe_dev(const struct device * dev,const struct fw_config ** matching_probe)96 bool fw_config_probe_dev(const struct device *dev, const struct fw_config **matching_probe)
97 {
98 const struct fw_config *probe;
99
100 if (matching_probe)
101 *matching_probe = NULL;
102
103 /* If the device does not have a probe list, then probing is not required. */
104 if (!dev->probe_list)
105 return true;
106
107 for (probe = dev->probe_list; probe && probe->mask != 0; probe++) {
108 if (!fw_config_probe(probe))
109 continue;
110
111 if (matching_probe)
112 *matching_probe = probe;
113 return true;
114 }
115
116 return false;
117 }
118
119 #if ENV_RAMSTAGE
120
121 /*
122 * The maximum number of fw_config fields is limited by the 64-bit mask that is used to
123 * represent them.
124 */
125 #define MAX_CACHE_ELEMENTS (8 * sizeof(uint64_t))
126
127 static const struct fw_config *cached_configs[MAX_CACHE_ELEMENTS];
128
probe_index(uint64_t mask)129 static size_t probe_index(uint64_t mask)
130 {
131 assert(mask);
132 return __ffs64(mask);
133 }
134
fw_config_get_found(uint64_t field_mask)135 const struct fw_config *fw_config_get_found(uint64_t field_mask)
136 {
137 const struct fw_config *config;
138 config = cached_configs[probe_index(field_mask)];
139 if (config && config->mask == field_mask)
140 return config;
141
142 return NULL;
143 }
144
fw_config_for_each_found(void (* cb)(const struct fw_config * config,void * arg),void * arg)145 void fw_config_for_each_found(void (*cb)(const struct fw_config *config, void *arg), void *arg)
146 {
147 size_t i;
148
149 for (i = 0; i < MAX_CACHE_ELEMENTS; ++i)
150 if (cached_configs[i])
151 cb(cached_configs[i], arg);
152 }
153
fw_config_init(void * unused)154 static void fw_config_init(void *unused)
155 {
156 struct device *dev;
157
158 for (dev = all_devices; dev; dev = dev->next) {
159 const struct fw_config *probe;
160
161 if (!fw_config_probe_dev(dev, &probe)) {
162 printk(BIOS_INFO, "%s disabled by fw_config\n", dev_path(dev));
163 dev->enabled = 0;
164 continue;
165 }
166
167 if (probe)
168 cached_configs[probe_index(probe->mask)] = probe;
169 }
170 }
171 BOOT_STATE_INIT_ENTRY(BS_DEV_INIT_CHIPS, BS_ON_ENTRY, fw_config_init, NULL);
172 #endif
173