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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, __pa(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}
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/module.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
22#include <asm/setup.h>
23#include <asm/page.h>
24#include <asm/mach/arch.h>
25#include <asm/mach-types.h>
26
27void __init early_init_dt_add_memory_arch(u64 base, u64 size)
28{
29 arm_add_memory(base, size);
30}
31
32void * __init early_init_dt_alloc_memory_arch(u64 size, u64 align)
33{
34 return alloc_bootmem_align(size, align);
35}
36
37void __init arm_dt_memblock_reserve(void)
38{
39 u64 *reserve_map, base, size;
40
41 if (!initial_boot_params)
42 return;
43
44 /* Reserve the dtb region */
45 memblock_reserve(virt_to_phys(initial_boot_params),
46 be32_to_cpu(initial_boot_params->totalsize));
47
48 /*
49 * Process the reserve map. This will probably overlap the initrd
50 * and dtb locations which are already reserved, but overlaping
51 * doesn't hurt anything
52 */
53 reserve_map = ((void*)initial_boot_params) +
54 be32_to_cpu(initial_boot_params->off_mem_rsvmap);
55 while (1) {
56 base = be64_to_cpup(reserve_map++);
57 size = be64_to_cpup(reserve_map++);
58 if (!size)
59 break;
60 memblock_reserve(base, size);
61 }
62}
63
64/**
65 * setup_machine_fdt - Machine setup when an dtb was passed to the kernel
66 * @dt_phys: physical address of dt blob
67 *
68 * If a dtb was passed to the kernel in r2, then use it to choose the
69 * correct machine_desc and to setup the system.
70 */
71struct machine_desc * __init setup_machine_fdt(unsigned int dt_phys)
72{
73 struct boot_param_header *devtree;
74 struct machine_desc *mdesc, *mdesc_best = NULL;
75 unsigned int score, mdesc_score = ~1;
76 unsigned long dt_root;
77 const char *model;
78
79 if (!dt_phys)
80 return NULL;
81
82 devtree = phys_to_virt(dt_phys);
83
84 /* check device tree validity */
85 if (be32_to_cpu(devtree->magic) != OF_DT_HEADER)
86 return NULL;
87
88 /* Search the mdescs for the 'best' compatible value match */
89 initial_boot_params = devtree;
90 dt_root = of_get_flat_dt_root();
91 for_each_machine_desc(mdesc) {
92 score = of_flat_dt_match(dt_root, mdesc->dt_compat);
93 if (score > 0 && score < mdesc_score) {
94 mdesc_best = mdesc;
95 mdesc_score = score;
96 }
97 }
98 if (!mdesc_best) {
99 const char *prop;
100 long size;
101
102 early_print("\nError: unrecognized/unsupported "
103 "device tree compatible list:\n[ ");
104
105 prop = of_get_flat_dt_prop(dt_root, "compatible", &size);
106 while (size > 0) {
107 early_print("'%s' ", prop);
108 size -= strlen(prop) + 1;
109 prop += strlen(prop) + 1;
110 }
111 early_print("]\n\n");
112
113 dump_machine_table(); /* does not return */
114 }
115
116 model = of_get_flat_dt_prop(dt_root, "model", NULL);
117 if (!model)
118 model = of_get_flat_dt_prop(dt_root, "compatible", NULL);
119 if (!model)
120 model = "<unknown>";
121 pr_info("Machine: %s, model: %s\n", mdesc_best->name, model);
122
123 /* Retrieve various information from the /chosen node */
124 of_scan_flat_dt(early_init_dt_scan_chosen, boot_command_line);
125 /* Initialize {size,address}-cells info */
126 of_scan_flat_dt(early_init_dt_scan_root, NULL);
127 /* Setup memory, calling early_init_dt_add_memory_arch */
128 of_scan_flat_dt(early_init_dt_scan_memory, NULL);
129
130 /* Change machine number to match the mdesc we're using */
131 __machine_arch_type = mdesc_best->nr;
132
133 return mdesc_best;
134}