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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/prom.h>
27#include <asm/smp_plat.h>
28#include <asm/mach/arch.h>
29#include <asm/mach-types.h>
30
31
32#ifdef CONFIG_SMP
33extern struct of_cpu_method __cpu_method_of_table[];
34
35static const struct of_cpu_method __cpu_method_of_table_sentinel
36 __used __section(__cpu_method_of_table_end);
37
38
39static int __init set_smp_ops_by_method(struct device_node *node)
40{
41 const char *method;
42 struct of_cpu_method *m = __cpu_method_of_table;
43
44 if (of_property_read_string(node, "enable-method", &method))
45 return 0;
46
47 for (; m->method; m++)
48 if (!strcmp(m->method, method)) {
49 smp_set_ops(m->ops);
50 return 1;
51 }
52
53 return 0;
54}
55#else
56static inline int set_smp_ops_by_method(struct device_node *node)
57{
58 return 1;
59}
60#endif
61
62
63/*
64 * arm_dt_init_cpu_maps - Function retrieves cpu nodes from the device tree
65 * and builds the cpu logical map array containing MPIDR values related to
66 * logical cpus
67 *
68 * Updates the cpu possible mask with the number of parsed cpu nodes
69 */
70void __init arm_dt_init_cpu_maps(void)
71{
72 /*
73 * Temp logical map is initialized with UINT_MAX values that are
74 * considered invalid logical map entries since the logical map must
75 * contain a list of MPIDR[23:0] values where MPIDR[31:24] must
76 * read as 0.
77 */
78 struct device_node *cpu, *cpus;
79 int found_method = 0;
80 u32 i, j, cpuidx = 1;
81 u32 mpidr = is_smp() ? read_cpuid_mpidr() & MPIDR_HWID_BITMASK : 0;
82
83 u32 tmp_map[NR_CPUS] = { [0 ... NR_CPUS-1] = MPIDR_INVALID };
84 bool bootcpu_valid = false;
85 cpus = of_find_node_by_path("/cpus");
86
87 if (!cpus)
88 return;
89
90 for_each_child_of_node(cpus, cpu) {
91 const __be32 *cell;
92 int prop_bytes;
93 u32 hwid;
94
95 if (of_node_cmp(cpu->type, "cpu"))
96 continue;
97
98 pr_debug(" * %s...\n", cpu->full_name);
99 /*
100 * A device tree containing CPU nodes with missing "reg"
101 * properties is considered invalid to build the
102 * cpu_logical_map.
103 */
104 cell = of_get_property(cpu, "reg", &prop_bytes);
105 if (!cell || prop_bytes < sizeof(*cell)) {
106 pr_debug(" * %s missing reg property\n",
107 cpu->full_name);
108 of_node_put(cpu);
109 return;
110 }
111
112 /*
113 * Bits n:24 must be set to 0 in the DT since the reg property
114 * defines the MPIDR[23:0].
115 */
116 do {
117 hwid = be32_to_cpu(*cell++);
118 prop_bytes -= sizeof(*cell);
119 } while (!hwid && prop_bytes > 0);
120
121 if (prop_bytes || (hwid & ~MPIDR_HWID_BITMASK)) {
122 of_node_put(cpu);
123 return;
124 }
125
126 /*
127 * Duplicate MPIDRs are a recipe for disaster.
128 * Scan all initialized entries and check for
129 * duplicates. If any is found just bail out.
130 * temp values were initialized to UINT_MAX
131 * to avoid matching valid MPIDR[23:0] values.
132 */
133 for (j = 0; j < cpuidx; j++)
134 if (WARN(tmp_map[j] == hwid,
135 "Duplicate /cpu reg properties in the DT\n")) {
136 of_node_put(cpu);
137 return;
138 }
139
140 /*
141 * Build a stashed array of MPIDR values. Numbering scheme
142 * requires that if detected the boot CPU must be assigned
143 * logical id 0. Other CPUs get sequential indexes starting
144 * from 1. If a CPU node with a reg property matching the
145 * boot CPU MPIDR is detected, this is recorded so that the
146 * logical map built from DT is validated and can be used
147 * to override the map created in smp_setup_processor_id().
148 */
149 if (hwid == mpidr) {
150 i = 0;
151 bootcpu_valid = true;
152 } else {
153 i = cpuidx++;
154 }
155
156 if (WARN(cpuidx > nr_cpu_ids, "DT /cpu %u nodes greater than "
157 "max cores %u, capping them\n",
158 cpuidx, nr_cpu_ids)) {
159 cpuidx = nr_cpu_ids;
160 of_node_put(cpu);
161 break;
162 }
163
164 tmp_map[i] = hwid;
165
166 if (!found_method)
167 found_method = set_smp_ops_by_method(cpu);
168 }
169
170 /*
171 * Fallback to an enable-method in the cpus node if nothing found in
172 * a cpu node.
173 */
174 if (!found_method)
175 set_smp_ops_by_method(cpus);
176
177 if (!bootcpu_valid) {
178 pr_warn("DT missing boot CPU MPIDR[23:0], fall back to default cpu_logical_map\n");
179 return;
180 }
181
182 /*
183 * Since the boot CPU node contains proper data, and all nodes have
184 * a reg property, the DT CPU list can be considered valid and the
185 * logical map created in smp_setup_processor_id() can be overridden
186 */
187 for (i = 0; i < cpuidx; i++) {
188 set_cpu_possible(i, true);
189 cpu_logical_map(i) = tmp_map[i];
190 pr_debug("cpu logical map 0x%x\n", cpu_logical_map(i));
191 }
192}
193
194bool arch_match_cpu_phys_id(int cpu, u64 phys_id)
195{
196 return phys_id == cpu_logical_map(cpu);
197}
198
199static const void * __init arch_get_next_mach(const char *const **match)
200{
201 static const struct machine_desc *mdesc = __arch_info_begin;
202 const struct machine_desc *m = mdesc;
203
204 if (m >= __arch_info_end)
205 return NULL;
206
207 mdesc++;
208 *match = m->dt_compat;
209 return m;
210}
211
212/**
213 * setup_machine_fdt - Machine setup when an dtb was passed to the kernel
214 * @dt_phys: physical address of dt blob
215 *
216 * If a dtb was passed to the kernel in r2, then use it to choose the
217 * correct machine_desc and to setup the system.
218 */
219const struct machine_desc * __init setup_machine_fdt(unsigned int dt_phys)
220{
221 const struct machine_desc *mdesc, *mdesc_best = NULL;
222
223#if defined(CONFIG_ARCH_MULTIPLATFORM) || defined(CONFIG_ARM_SINGLE_ARMV7M)
224 DT_MACHINE_START(GENERIC_DT, "Generic DT based system")
225 .l2c_aux_val = 0x0,
226 .l2c_aux_mask = ~0x0,
227 MACHINE_END
228
229 mdesc_best = &__mach_desc_GENERIC_DT;
230#endif
231
232 if (!dt_phys || !early_init_dt_verify(phys_to_virt(dt_phys)))
233 return NULL;
234
235 mdesc = of_flat_dt_match_machine(mdesc_best, arch_get_next_mach);
236
237 if (!mdesc) {
238 const char *prop;
239 int size;
240 unsigned long dt_root;
241
242 early_print("\nError: unrecognized/unsupported "
243 "device tree compatible list:\n[ ");
244
245 dt_root = of_get_flat_dt_root();
246 prop = of_get_flat_dt_prop(dt_root, "compatible", &size);
247 while (size > 0) {
248 early_print("'%s' ", prop);
249 size -= strlen(prop) + 1;
250 prop += strlen(prop) + 1;
251 }
252 early_print("]\n\n");
253
254 dump_machine_table(); /* does not return */
255 }
256
257 /* We really don't want to do this, but sometimes firmware provides buggy data */
258 if (mdesc->dt_fixup)
259 mdesc->dt_fixup();
260
261 early_init_dt_scan_nodes();
262
263 /* Change machine number to match the mdesc we're using */
264 __machine_arch_type = mdesc->nr;
265
266 return mdesc;
267}
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/smp.h>
17
18#include <asm/cputype.h>
19#include <asm/setup.h>
20#include <asm/page.h>
21#include <asm/prom.h>
22#include <asm/smp_plat.h>
23#include <asm/mach/arch.h>
24#include <asm/mach-types.h>
25
26
27#ifdef CONFIG_SMP
28extern struct of_cpu_method __cpu_method_of_table[];
29
30static const struct of_cpu_method __cpu_method_of_table_sentinel
31 __used __section("__cpu_method_of_table_end");
32
33
34static int __init set_smp_ops_by_method(struct device_node *node)
35{
36 const char *method;
37 struct of_cpu_method *m = __cpu_method_of_table;
38
39 if (of_property_read_string(node, "enable-method", &method))
40 return 0;
41
42 for (; m->method; m++)
43 if (!strcmp(m->method, method)) {
44 smp_set_ops(m->ops);
45 return 1;
46 }
47
48 return 0;
49}
50#else
51static inline int set_smp_ops_by_method(struct device_node *node)
52{
53 return 1;
54}
55#endif
56
57
58/*
59 * arm_dt_init_cpu_maps - Function retrieves cpu nodes from the device tree
60 * and builds the cpu logical map array containing MPIDR values related to
61 * logical cpus
62 *
63 * Updates the cpu possible mask with the number of parsed cpu nodes
64 */
65void __init arm_dt_init_cpu_maps(void)
66{
67 /*
68 * Temp logical map is initialized with UINT_MAX values that are
69 * considered invalid logical map entries since the logical map must
70 * contain a list of MPIDR[23:0] values where MPIDR[31:24] must
71 * read as 0.
72 */
73 struct device_node *cpu, *cpus;
74 int found_method = 0;
75 u32 i, j, cpuidx = 1;
76 u32 mpidr = is_smp() ? read_cpuid_mpidr() & MPIDR_HWID_BITMASK : 0;
77
78 u32 tmp_map[NR_CPUS] = { [0 ... NR_CPUS-1] = MPIDR_INVALID };
79 bool bootcpu_valid = false;
80 cpus = of_find_node_by_path("/cpus");
81
82 if (!cpus)
83 return;
84
85 for_each_of_cpu_node(cpu) {
86 u32 hwid = of_get_cpu_hwid(cpu, 0);
87
88 pr_debug(" * %pOF...\n", cpu);
89
90 /*
91 * Bits n:24 must be set to 0 in the DT since the reg property
92 * defines the MPIDR[23:0].
93 */
94 if (hwid & ~MPIDR_HWID_BITMASK) {
95 of_node_put(cpu);
96 return;
97 }
98
99 /*
100 * Duplicate MPIDRs are a recipe for disaster.
101 * Scan all initialized entries and check for
102 * duplicates. If any is found just bail out.
103 * temp values were initialized to UINT_MAX
104 * to avoid matching valid MPIDR[23:0] values.
105 */
106 for (j = 0; j < cpuidx; j++)
107 if (WARN(tmp_map[j] == hwid,
108 "Duplicate /cpu reg properties in the DT\n")) {
109 of_node_put(cpu);
110 return;
111 }
112
113 /*
114 * Build a stashed array of MPIDR values. Numbering scheme
115 * requires that if detected the boot CPU must be assigned
116 * logical id 0. Other CPUs get sequential indexes starting
117 * from 1. If a CPU node with a reg property matching the
118 * boot CPU MPIDR is detected, this is recorded so that the
119 * logical map built from DT is validated and can be used
120 * to override the map created in smp_setup_processor_id().
121 */
122 if (hwid == mpidr) {
123 i = 0;
124 bootcpu_valid = true;
125 } else {
126 i = cpuidx++;
127 }
128
129 if (WARN(cpuidx > nr_cpu_ids, "DT /cpu %u nodes greater than "
130 "max cores %u, capping them\n",
131 cpuidx, nr_cpu_ids)) {
132 cpuidx = nr_cpu_ids;
133 of_node_put(cpu);
134 break;
135 }
136
137 tmp_map[i] = hwid;
138
139 if (!found_method)
140 found_method = set_smp_ops_by_method(cpu);
141 }
142
143 /*
144 * Fallback to an enable-method in the cpus node if nothing found in
145 * a cpu node.
146 */
147 if (!found_method)
148 set_smp_ops_by_method(cpus);
149
150 if (!bootcpu_valid) {
151 pr_warn("DT missing boot CPU MPIDR[23:0], fall back to default cpu_logical_map\n");
152 return;
153 }
154
155 /*
156 * Since the boot CPU node contains proper data, and all nodes have
157 * a reg property, the DT CPU list can be considered valid and the
158 * logical map created in smp_setup_processor_id() can be overridden
159 */
160 for (i = 0; i < cpuidx; i++) {
161 set_cpu_possible(i, true);
162 cpu_logical_map(i) = tmp_map[i];
163 pr_debug("cpu logical map 0x%x\n", cpu_logical_map(i));
164 }
165}
166
167bool arch_match_cpu_phys_id(int cpu, u64 phys_id)
168{
169 return phys_id == cpu_logical_map(cpu);
170}
171
172static const void * __init arch_get_next_mach(const char *const **match)
173{
174 static const struct machine_desc *mdesc = __arch_info_begin;
175 const struct machine_desc *m = mdesc;
176
177 if (m >= __arch_info_end)
178 return NULL;
179
180 mdesc++;
181 *match = m->dt_compat;
182 return m;
183}
184
185/**
186 * setup_machine_fdt - Machine setup when an dtb was passed to the kernel
187 * @dt_virt: virtual address of dt blob
188 *
189 * If a dtb was passed to the kernel in r2, then use it to choose the
190 * correct machine_desc and to setup the system.
191 */
192const struct machine_desc * __init setup_machine_fdt(void *dt_virt)
193{
194 const struct machine_desc *mdesc, *mdesc_best = NULL;
195
196 DT_MACHINE_START(GENERIC_DT, "Generic DT based system")
197 .l2c_aux_val = 0x0,
198 .l2c_aux_mask = ~0x0,
199 MACHINE_END
200
201 mdesc_best = &__mach_desc_GENERIC_DT;
202
203 if (!dt_virt || !early_init_dt_verify(dt_virt))
204 return NULL;
205
206 mdesc = of_flat_dt_match_machine(mdesc_best, arch_get_next_mach);
207
208 if (!mdesc) {
209 const char *prop;
210 int size;
211 unsigned long dt_root;
212
213 early_print("\nError: unrecognized/unsupported "
214 "device tree compatible list:\n[ ");
215
216 dt_root = of_get_flat_dt_root();
217 prop = of_get_flat_dt_prop(dt_root, "compatible", &size);
218 while (size > 0) {
219 early_print("'%s' ", prop);
220 size -= strlen(prop) + 1;
221 prop += strlen(prop) + 1;
222 }
223 early_print("]\n\n");
224
225 dump_machine_table(); /* does not return */
226 }
227
228 /* We really don't want to do this, but sometimes firmware provides buggy data */
229 if (mdesc->dt_fixup)
230 mdesc->dt_fixup();
231
232 early_init_dt_scan_nodes();
233
234 /* Change machine number to match the mdesc we're using */
235 __machine_arch_type = mdesc->nr;
236
237 return mdesc;
238}