aboutsummaryrefslogtreecommitdiff
path: root/arch/arm/kernel/devtree.c
blob: 5859c8bc727c4254bc7e8fa254a4271d6b214242 (plain)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
223
224
225
226
227
228
229
230
231
232
233
234
235
236
237
238
239
240
241
242
243
244
245
246
247
248
249
/*
 *  linux/arch/arm/kernel/devtree.c
 *
 *  Copyright (C) 2009 Canonical Ltd. <jeremy.kerr@canonical.com>
 *
 * This program is free software; you can redistribute it and/or modify
 * it under the terms of the GNU General Public License version 2 as
 * published by the Free Software Foundation.
 */

#include <linux/init.h>
#include <linux/export.h>
#include <linux/errno.h>
#include <linux/types.h>
#include <linux/bootmem.h>
#include <linux/memblock.h>
#include <linux/of.h>
#include <linux/of_fdt.h>
#include <linux/of_irq.h>
#include <linux/of_platform.h>

#include <asm/cputype.h>
#include <asm/setup.h>
#include <asm/page.h>
#include <asm/smp_plat.h>
#include <asm/mach/arch.h>
#include <asm/mach-types.h>

void __init early_init_dt_add_memory_arch(u64 base, u64 size)
{
	arm_add_memory(base, size);
}

void * __init early_init_dt_alloc_memory_arch(u64 size, u64 align)
{
	return alloc_bootmem_align(size, align);
}

void __init arm_dt_memblock_reserve(void)
{
	u64 *reserve_map, base, size;

	if (!initial_boot_params)
		return;

	/* Reserve the dtb region */
	memblock_reserve(virt_to_phys(initial_boot_params),
			 be32_to_cpu(initial_boot_params->totalsize));

	/*
	 * Process the reserve map.  This will probably overlap the initrd
	 * and dtb locations which are already reserved, but overlaping
	 * doesn't hurt anything
	 */
	reserve_map = ((void*)initial_boot_params) +
			be32_to_cpu(initial_boot_params->off_mem_rsvmap);
	while (1) {
		base = be64_to_cpup(reserve_map++);
		size = be64_to_cpup(reserve_map++);
		if (!size)
			break;
		memblock_reserve(base, size);
	}
}

/*
 * arm_dt_init_cpu_maps - Function retrieves cpu nodes from the device tree
 * and builds the cpu logical map array containing MPIDR values related to
 * logical cpus
 *
 * Updates the cpu possible mask with the number of parsed cpu nodes
 */
void __init arm_dt_init_cpu_maps(void)
{
	/*
	 * Temp logical map is initialized with UINT_MAX values that are
	 * considered invalid logical map entries since the logical map must
	 * contain a list of MPIDR[23:0] values where MPIDR[31:24] must
	 * read as 0.
	 */
	struct device_node *cpu, *cpus;
	u32 i, j, cpuidx = 1;
	u32 mpidr = is_smp() ? read_cpuid_mpidr() & MPIDR_HWID_BITMASK : 0;

	u32 tmp_map[NR_CPUS] = { [0 ... NR_CPUS-1] = MPIDR_INVALID };
	bool bootcpu_valid = false;
	cpus = of_find_node_by_path("/cpus");

	if (!cpus)
		return;

	for_each_child_of_node(cpus, cpu) {
		u32 hwid;

		if (of_node_cmp(cpu->type, "cpu"))
			continue;

		pr_debug(" * %s...\n", cpu->full_name);
		/*
		 * A device tree containing CPU nodes with missing "reg"
		 * properties is considered invalid to build the
		 * cpu_logical_map.
		 */
		if (of_property_read_u32(cpu, "reg", &hwid)) {
			pr_debug(" * %s missing reg property\n",
				     cpu->full_name);
			return;
		}

		/*
		 * 8 MSBs must be set to 0 in the DT since the reg property
		 * defines the MPIDR[23:0].
		 */
		if (hwid & ~MPIDR_HWID_BITMASK)
			return;

		/*
		 * Duplicate MPIDRs are a recipe for disaster.
		 * Scan all initialized entries and check for
		 * duplicates. If any is found just bail out.
		 * temp values were initialized to UINT_MAX
		 * to avoid matching valid MPIDR[23:0] values.
		 */
		for (j = 0; j < cpuidx; j++)
			if (WARN(tmp_map[j] == hwid, "Duplicate /cpu reg "
						     "properties in the DT\n"))
				return;

		/*
		 * Build a stashed array of MPIDR values. Numbering scheme
		 * requires that if detected the boot CPU must be assigned
		 * logical id 0. Other CPUs get sequential indexes starting
		 * from 1. If a CPU node with a reg property matching the
		 * boot CPU MPIDR is detected, this is recorded so that the
		 * logical map built from DT is validated and can be used
		 * to override the map created in smp_setup_processor_id().
		 */
		if (hwid == mpidr) {
			i = 0;
			bootcpu_valid = true;
		} else {
			i = cpuidx++;
		}

		if (WARN(cpuidx > nr_cpu_ids, "DT /cpu %u nodes greater than "
					       "max cores %u, capping them\n",
					       cpuidx, nr_cpu_ids)) {
			cpuidx = nr_cpu_ids;
			break;
		}

		tmp_map[i] = hwid;
	}

	if (!bootcpu_valid) {
		pr_warn("DT missing boot CPU MPIDR[23:0], fall back to default cpu_logical_map\n");
		return;
	}

	/*
	 * Since the boot CPU node contains proper data, and all nodes have
	 * a reg property, the DT CPU list can be considered valid and the
	 * logical map created in smp_setup_processor_id() can be overridden
	 */
	for (i = 0; i < cpuidx; i++) {
		set_cpu_possible(i, true);
		cpu_logical_map(i) = tmp_map[i];
		pr_debug("cpu logical map 0x%x\n", cpu_logical_map(i));
	}
}

/**
 * setup_machine_fdt - Machine setup when an dtb was passed to the kernel
 * @dt_phys: physical address of dt blob
 *
 * If a dtb was passed to the kernel in r2, then use it to choose the
 * correct machine_desc and to setup the system.
 */
struct machine_desc * __init setup_machine_fdt(unsigned int dt_phys)
{
	struct boot_param_header *devtree;
	struct machine_desc *mdesc, *mdesc_best = NULL;
	unsigned int score, mdesc_score = ~1;
	unsigned long dt_root;
	const char *model;

#ifdef CONFIG_ARCH_MULTIPLATFORM
	DT_MACHINE_START(GENERIC_DT, "Generic DT based system")
	MACHINE_END

	mdesc_best = (struct machine_desc *)&__mach_desc_GENERIC_DT;
#endif

	if (!dt_phys)
		return NULL;

	devtree = phys_to_virt(dt_phys);

	/* check device tree validity */
	if (be32_to_cpu(devtree->magic) != OF_DT_HEADER)
		return NULL;

	/* Search the mdescs for the 'best' compatible value match */
	initial_boot_params = devtree;
	dt_root = of_get_flat_dt_root();
	for_each_machine_desc(mdesc) {
		score = of_flat_dt_match(dt_root, mdesc->dt_compat);
		if (score > 0 && score < mdesc_score) {
			mdesc_best = mdesc;
			mdesc_score = score;
		}
	}
	if (!mdesc_best) {
		const char *prop;
		long size;

		early_print("\nError: unrecognized/unsupported "
			    "device tree compatible list:\n[ ");

		prop = of_get_flat_dt_prop(dt_root, "compatible", &size);
		while (size > 0) {
			early_print("'%s' ", prop);
			size -= strlen(prop) + 1;
			prop += strlen(prop) + 1;
		}
		early_print("]\n\n");

		dump_machine_table(); /* does not return */
	}

	model = of_get_flat_dt_prop(dt_root, "model", NULL);
	if (!model)
		model = of_get_flat_dt_prop(dt_root, "compatible", NULL);
	if (!model)
		model = "<unknown>";
	pr_info("Machine: %s, model: %s\n", mdesc_best->name, model);

	/* Retrieve various information from the /chosen node */
	of_scan_flat_dt(early_init_dt_scan_chosen, boot_command_line);
	/* Initialize {size,address}-cells info */
	of_scan_flat_dt(early_init_dt_scan_root, NULL);
	/* Setup memory, calling early_init_dt_add_memory_arch */
	of_scan_flat_dt(early_init_dt_scan_memory, NULL);

	/* Change machine number to match the mdesc we're using */
	__machine_arch_type = mdesc_best->nr;

	return mdesc_best;
}