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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/*
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}