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1/*
2 * linux/arch/arm/kernel/devtree.c
3 *
4 * Copyright (C) 2009 Canonical Ltd. <jeremy.kerr@canonical.com>
5 *
6 * This program is free software; you can redistribute it and/or modify
7 * it under the terms of the GNU General Public License version 2 as
8 * published by the Free Software Foundation.
9 */
10
11#include <linux/init.h>
12#include <linux/export.h>
13#include <linux/errno.h>
14#include <linux/types.h>
15#include <linux/bootmem.h>
16#include <linux/memblock.h>
17#include <linux/of.h>
18#include <linux/of_fdt.h>
19#include <linux/of_irq.h>
20#include <linux/of_platform.h>
21#include <linux/smp.h>
22
23#include <asm/cputype.h>
24#include <asm/setup.h>
25#include <asm/page.h>
26#include <asm/smp_plat.h>
27#include <asm/mach/arch.h>
28#include <asm/mach-types.h>
29
30
31#ifdef CONFIG_SMP
32extern struct of_cpu_method __cpu_method_of_table[];
33
34static const struct of_cpu_method __cpu_method_of_table_sentinel
35 __used __section(__cpu_method_of_table_end);
36
37
38static int __init set_smp_ops_by_method(struct device_node *node)
39{
40 const char *method;
41 struct of_cpu_method *m = __cpu_method_of_table;
42
43 if (of_property_read_string(node, "enable-method", &method))
44 return 0;
45
46 for (; m->method; m++)
47 if (!strcmp(m->method, method)) {
48 smp_set_ops(m->ops);
49 return 1;
50 }
51
52 return 0;
53}
54#else
55static inline int set_smp_ops_by_method(struct device_node *node)
56{
57 return 1;
58}
59#endif
60
61
62/*
63 * arm_dt_init_cpu_maps - Function retrieves cpu nodes from the device tree
64 * and builds the cpu logical map array containing MPIDR values related to
65 * logical cpus
66 *
67 * Updates the cpu possible mask with the number of parsed cpu nodes
68 */
69void __init arm_dt_init_cpu_maps(void)
70{
71 /*
72 * Temp logical map is initialized with UINT_MAX values that are
73 * considered invalid logical map entries since the logical map must
74 * contain a list of MPIDR[23:0] values where MPIDR[31:24] must
75 * read as 0.
76 */
77 struct device_node *cpu, *cpus;
78 int found_method = 0;
79 u32 i, j, cpuidx = 1;
80 u32 mpidr = is_smp() ? read_cpuid_mpidr() & MPIDR_HWID_BITMASK : 0;
81
82 u32 tmp_map[NR_CPUS] = { [0 ... NR_CPUS-1] = MPIDR_INVALID };
83 bool bootcpu_valid = false;
84 cpus = of_find_node_by_path("/cpus");
85
86 if (!cpus)
87 return;
88
89 for_each_child_of_node(cpus, cpu) {
90 u32 hwid;
91
92 if (of_node_cmp(cpu->type, "cpu"))
93 continue;
94
95 pr_debug(" * %s...\n", cpu->full_name);
96 /*
97 * A device tree containing CPU nodes with missing "reg"
98 * properties is considered invalid to build the
99 * cpu_logical_map.
100 */
101 if (of_property_read_u32(cpu, "reg", &hwid)) {
102 pr_debug(" * %s missing reg property\n",
103 cpu->full_name);
104 of_node_put(cpu);
105 return;
106 }
107
108 /*
109 * 8 MSBs must be set to 0 in the DT since the reg property
110 * defines the MPIDR[23:0].
111 */
112 if (hwid & ~MPIDR_HWID_BITMASK) {
113 of_node_put(cpu);
114 return;
115 }
116
117 /*
118 * Duplicate MPIDRs are a recipe for disaster.
119 * Scan all initialized entries and check for
120 * duplicates. If any is found just bail out.
121 * temp values were initialized to UINT_MAX
122 * to avoid matching valid MPIDR[23:0] values.
123 */
124 for (j = 0; j < cpuidx; j++)
125 if (WARN(tmp_map[j] == hwid,
126 "Duplicate /cpu reg properties in the DT\n")) {
127 of_node_put(cpu);
128 return;
129 }
130
131 /*
132 * Build a stashed array of MPIDR values. Numbering scheme
133 * requires that if detected the boot CPU must be assigned
134 * logical id 0. Other CPUs get sequential indexes starting
135 * from 1. If a CPU node with a reg property matching the
136 * boot CPU MPIDR is detected, this is recorded so that the
137 * logical map built from DT is validated and can be used
138 * to override the map created in smp_setup_processor_id().
139 */
140 if (hwid == mpidr) {
141 i = 0;
142 bootcpu_valid = true;
143 } else {
144 i = cpuidx++;
145 }
146
147 if (WARN(cpuidx > nr_cpu_ids, "DT /cpu %u nodes greater than "
148 "max cores %u, capping them\n",
149 cpuidx, nr_cpu_ids)) {
150 cpuidx = nr_cpu_ids;
151 of_node_put(cpu);
152 break;
153 }
154
155 tmp_map[i] = hwid;
156
157 if (!found_method)
158 found_method = set_smp_ops_by_method(cpu);
159 }
160
161 /*
162 * Fallback to an enable-method in the cpus node if nothing found in
163 * a cpu node.
164 */
165 if (!found_method)
166 set_smp_ops_by_method(cpus);
167
168 if (!bootcpu_valid) {
169 pr_warn("DT missing boot CPU MPIDR[23:0], fall back to default cpu_logical_map\n");
170 return;
171 }
172
173 /*
174 * Since the boot CPU node contains proper data, and all nodes have
175 * a reg property, the DT CPU list can be considered valid and the
176 * logical map created in smp_setup_processor_id() can be overridden
177 */
178 for (i = 0; i < cpuidx; i++) {
179 set_cpu_possible(i, true);
180 cpu_logical_map(i) = tmp_map[i];
181 pr_debug("cpu logical map 0x%x\n", cpu_logical_map(i));
182 }
183}
184
185bool arch_match_cpu_phys_id(int cpu, u64 phys_id)
186{
187 return phys_id == cpu_logical_map(cpu);
188}
189
190static const void * __init arch_get_next_mach(const char *const **match)
191{
192 static const struct machine_desc *mdesc = __arch_info_begin;
193 const struct machine_desc *m = mdesc;
194
195 if (m >= __arch_info_end)
196 return NULL;
197
198 mdesc++;
199 *match = m->dt_compat;
200 return m;
201}
202
203/**
204 * setup_machine_fdt - Machine setup when an dtb was passed to the kernel
205 * @dt_phys: physical address of dt blob
206 *
207 * If a dtb was passed to the kernel in r2, then use it to choose the
208 * correct machine_desc and to setup the system.
209 */
210const struct machine_desc * __init setup_machine_fdt(unsigned int dt_phys)
211{
212 const struct machine_desc *mdesc, *mdesc_best = NULL;
213
214#if defined(CONFIG_ARCH_MULTIPLATFORM) || defined(CONFIG_ARM_SINGLE_ARMV7M)
215 DT_MACHINE_START(GENERIC_DT, "Generic DT based system")
216 MACHINE_END
217
218 mdesc_best = &__mach_desc_GENERIC_DT;
219#endif
220
221 if (!dt_phys || !early_init_dt_verify(phys_to_virt(dt_phys)))
222 return NULL;
223
224 mdesc = of_flat_dt_match_machine(mdesc_best, arch_get_next_mach);
225
226 if (!mdesc) {
227 const char *prop;
228 int size;
229 unsigned long dt_root;
230
231 early_print("\nError: unrecognized/unsupported "
232 "device tree compatible list:\n[ ");
233
234 dt_root = of_get_flat_dt_root();
235 prop = of_get_flat_dt_prop(dt_root, "compatible", &size);
236 while (size > 0) {
237 early_print("'%s' ", prop);
238 size -= strlen(prop) + 1;
239 prop += strlen(prop) + 1;
240 }
241 early_print("]\n\n");
242
243 dump_machine_table(); /* does not return */
244 }
245
246 /* We really don't want to do this, but sometimes firmware provides buggy data */
247 if (mdesc->dt_fixup)
248 mdesc->dt_fixup();
249
250 early_init_dt_scan_nodes();
251
252 /* Change machine number to match the mdesc we're using */
253 __machine_arch_type = mdesc->nr;
254
255 return mdesc;
256}
1// SPDX-License-Identifier: GPL-2.0-only
2/*
3 * linux/arch/arm/kernel/devtree.c
4 *
5 * Copyright (C) 2009 Canonical Ltd. <jeremy.kerr@canonical.com>
6 */
7
8#include <linux/init.h>
9#include <linux/export.h>
10#include <linux/errno.h>
11#include <linux/types.h>
12#include <linux/memblock.h>
13#include <linux/of.h>
14#include <linux/of_fdt.h>
15#include <linux/of_irq.h>
16#include <linux/of_platform.h>
17#include <linux/smp.h>
18
19#include <asm/cputype.h>
20#include <asm/setup.h>
21#include <asm/page.h>
22#include <asm/prom.h>
23#include <asm/smp_plat.h>
24#include <asm/mach/arch.h>
25#include <asm/mach-types.h>
26
27
28#ifdef CONFIG_SMP
29extern struct of_cpu_method __cpu_method_of_table[];
30
31static const struct of_cpu_method __cpu_method_of_table_sentinel
32 __used __section("__cpu_method_of_table_end");
33
34
35static int __init set_smp_ops_by_method(struct device_node *node)
36{
37 const char *method;
38 struct of_cpu_method *m = __cpu_method_of_table;
39
40 if (of_property_read_string(node, "enable-method", &method))
41 return 0;
42
43 for (; m->method; m++)
44 if (!strcmp(m->method, method)) {
45 smp_set_ops(m->ops);
46 return 1;
47 }
48
49 return 0;
50}
51#else
52static inline int set_smp_ops_by_method(struct device_node *node)
53{
54 return 1;
55}
56#endif
57
58
59/*
60 * arm_dt_init_cpu_maps - Function retrieves cpu nodes from the device tree
61 * and builds the cpu logical map array containing MPIDR values related to
62 * logical cpus
63 *
64 * Updates the cpu possible mask with the number of parsed cpu nodes
65 */
66void __init arm_dt_init_cpu_maps(void)
67{
68 /*
69 * Temp logical map is initialized with UINT_MAX values that are
70 * considered invalid logical map entries since the logical map must
71 * contain a list of MPIDR[23:0] values where MPIDR[31:24] must
72 * read as 0.
73 */
74 struct device_node *cpu, *cpus;
75 int found_method = 0;
76 u32 i, j, cpuidx = 1;
77 u32 mpidr = is_smp() ? read_cpuid_mpidr() & MPIDR_HWID_BITMASK : 0;
78
79 u32 tmp_map[NR_CPUS] = { [0 ... NR_CPUS-1] = MPIDR_INVALID };
80 bool bootcpu_valid = false;
81 cpus = of_find_node_by_path("/cpus");
82
83 if (!cpus)
84 return;
85
86 for_each_of_cpu_node(cpu) {
87 u32 hwid = of_get_cpu_hwid(cpu, 0);
88
89 pr_debug(" * %pOF...\n", cpu);
90
91 /*
92 * Bits n:24 must be set to 0 in the DT since the reg property
93 * defines the MPIDR[23:0].
94 */
95 if (hwid & ~MPIDR_HWID_BITMASK) {
96 of_node_put(cpu);
97 return;
98 }
99
100 /*
101 * Duplicate MPIDRs are a recipe for disaster.
102 * Scan all initialized entries and check for
103 * duplicates. If any is found just bail out.
104 * temp values were initialized to UINT_MAX
105 * to avoid matching valid MPIDR[23:0] values.
106 */
107 for (j = 0; j < cpuidx; j++)
108 if (WARN(tmp_map[j] == hwid,
109 "Duplicate /cpu reg properties in the DT\n")) {
110 of_node_put(cpu);
111 return;
112 }
113
114 /*
115 * Build a stashed array of MPIDR values. Numbering scheme
116 * requires that if detected the boot CPU must be assigned
117 * logical id 0. Other CPUs get sequential indexes starting
118 * from 1. If a CPU node with a reg property matching the
119 * boot CPU MPIDR is detected, this is recorded so that the
120 * logical map built from DT is validated and can be used
121 * to override the map created in smp_setup_processor_id().
122 */
123 if (hwid == mpidr) {
124 i = 0;
125 bootcpu_valid = true;
126 } else {
127 i = cpuidx++;
128 }
129
130 if (WARN(cpuidx > nr_cpu_ids, "DT /cpu %u nodes greater than "
131 "max cores %u, capping them\n",
132 cpuidx, nr_cpu_ids)) {
133 cpuidx = nr_cpu_ids;
134 of_node_put(cpu);
135 break;
136 }
137
138 tmp_map[i] = hwid;
139
140 if (!found_method)
141 found_method = set_smp_ops_by_method(cpu);
142 }
143
144 /*
145 * Fallback to an enable-method in the cpus node if nothing found in
146 * a cpu node.
147 */
148 if (!found_method)
149 set_smp_ops_by_method(cpus);
150
151 if (!bootcpu_valid) {
152 pr_warn("DT missing boot CPU MPIDR[23:0], fall back to default cpu_logical_map\n");
153 return;
154 }
155
156 /*
157 * Since the boot CPU node contains proper data, and all nodes have
158 * a reg property, the DT CPU list can be considered valid and the
159 * logical map created in smp_setup_processor_id() can be overridden
160 */
161 for (i = 0; i < cpuidx; i++) {
162 set_cpu_possible(i, true);
163 cpu_logical_map(i) = tmp_map[i];
164 pr_debug("cpu logical map 0x%x\n", cpu_logical_map(i));
165 }
166}
167
168bool arch_match_cpu_phys_id(int cpu, u64 phys_id)
169{
170 return phys_id == cpu_logical_map(cpu);
171}
172
173static const void * __init arch_get_next_mach(const char *const **match)
174{
175 static const struct machine_desc *mdesc = __arch_info_begin;
176 const struct machine_desc *m = mdesc;
177
178 if (m >= __arch_info_end)
179 return NULL;
180
181 mdesc++;
182 *match = m->dt_compat;
183 return m;
184}
185
186/**
187 * setup_machine_fdt - Machine setup when an dtb was passed to the kernel
188 * @dt_virt: virtual address of dt blob
189 *
190 * If a dtb was passed to the kernel in r2, then use it to choose the
191 * correct machine_desc and to setup the system.
192 */
193const struct machine_desc * __init setup_machine_fdt(void *dt_virt)
194{
195 const struct machine_desc *mdesc, *mdesc_best = NULL;
196
197 DT_MACHINE_START(GENERIC_DT, "Generic DT based system")
198 .l2c_aux_val = 0x0,
199 .l2c_aux_mask = ~0x0,
200 MACHINE_END
201
202 mdesc_best = &__mach_desc_GENERIC_DT;
203
204 if (!dt_virt || !early_init_dt_verify(dt_virt))
205 return NULL;
206
207 mdesc = of_flat_dt_match_machine(mdesc_best, arch_get_next_mach);
208
209 if (!mdesc) {
210 const char *prop;
211 int size;
212 unsigned long dt_root;
213
214 early_print("\nError: unrecognized/unsupported "
215 "device tree compatible list:\n[ ");
216
217 dt_root = of_get_flat_dt_root();
218 prop = of_get_flat_dt_prop(dt_root, "compatible", &size);
219 while (size > 0) {
220 early_print("'%s' ", prop);
221 size -= strlen(prop) + 1;
222 prop += strlen(prop) + 1;
223 }
224 early_print("]\n\n");
225
226 dump_machine_table(); /* does not return */
227 }
228
229 /* We really don't want to do this, but sometimes firmware provides buggy data */
230 if (mdesc->dt_fixup)
231 mdesc->dt_fixup();
232
233 early_init_dt_scan_nodes();
234
235 /* Change machine number to match the mdesc we're using */
236 __machine_arch_type = mdesc->nr;
237
238 return mdesc;
239}