2 * linux/arch/arm/kernel/devtree.c
4 * Copyright (C) 2009 Canonical Ltd. <jeremy.kerr@canonical.com>
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.
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>
18 #include <linux/of_fdt.h>
19 #include <linux/of_irq.h>
20 #include <linux/of_platform.h>
21 #include <linux/smp.h>
23 #include <asm/cputype.h>
24 #include <asm/setup.h>
26 #include <asm/smp_plat.h>
27 #include <asm/mach/arch.h>
28 #include <asm/mach-types.h>
30 void __init early_init_dt_add_memory_arch(u64 base, u64 size)
32 arm_add_memory(base, size);
36 extern struct of_cpu_method __cpu_method_of_table[];
38 static const struct of_cpu_method __cpu_method_of_table_sentinel
39 __used __section(__cpu_method_of_table_end);
42 static int __init set_smp_ops_by_method(struct device_node *node)
45 struct of_cpu_method *m = __cpu_method_of_table;
47 if (of_property_read_string(node, "enable-method", &method))
50 for (; m->method; m++)
51 if (!strcmp(m->method, method)) {
59 static inline int set_smp_ops_by_method(struct device_node *node)
67 * arm_dt_init_cpu_maps - Function retrieves cpu nodes from the device tree
68 * and builds the cpu logical map array containing MPIDR values related to
71 * Updates the cpu possible mask with the number of parsed cpu nodes
73 void __init arm_dt_init_cpu_maps(void)
76 * Temp logical map is initialized with UINT_MAX values that are
77 * considered invalid logical map entries since the logical map must
78 * contain a list of MPIDR[23:0] values where MPIDR[31:24] must
81 struct device_node *cpu, *cpus;
84 u32 mpidr = is_smp() ? read_cpuid_mpidr() & MPIDR_HWID_BITMASK : 0;
86 u32 tmp_map[NR_CPUS] = { [0 ... NR_CPUS-1] = MPIDR_INVALID };
87 bool bootcpu_valid = false;
88 cpus = of_find_node_by_path("/cpus");
93 for_each_child_of_node(cpus, cpu) {
96 if (of_node_cmp(cpu->type, "cpu"))
99 pr_debug(" * %s...\n", cpu->full_name);
101 * A device tree containing CPU nodes with missing "reg"
102 * properties is considered invalid to build the
105 if (of_property_read_u32(cpu, "reg", &hwid)) {
106 pr_debug(" * %s missing reg property\n",
112 * 8 MSBs must be set to 0 in the DT since the reg property
113 * defines the MPIDR[23:0].
115 if (hwid & ~MPIDR_HWID_BITMASK)
119 * Duplicate MPIDRs are a recipe for disaster.
120 * Scan all initialized entries and check for
121 * duplicates. If any is found just bail out.
122 * temp values were initialized to UINT_MAX
123 * to avoid matching valid MPIDR[23:0] values.
125 for (j = 0; j < cpuidx; j++)
126 if (WARN(tmp_map[j] == hwid, "Duplicate /cpu reg "
127 "properties in the DT\n"))
131 * Build a stashed array of MPIDR values. Numbering scheme
132 * requires that if detected the boot CPU must be assigned
133 * logical id 0. Other CPUs get sequential indexes starting
134 * from 1. If a CPU node with a reg property matching the
135 * boot CPU MPIDR is detected, this is recorded so that the
136 * logical map built from DT is validated and can be used
137 * to override the map created in smp_setup_processor_id().
141 bootcpu_valid = true;
146 if (WARN(cpuidx > nr_cpu_ids, "DT /cpu %u nodes greater than "
147 "max cores %u, capping them\n",
148 cpuidx, nr_cpu_ids)) {
156 found_method = set_smp_ops_by_method(cpu);
160 * Fallback to an enable-method in the cpus node if nothing found in
164 set_smp_ops_by_method(cpus);
166 if (!bootcpu_valid) {
167 pr_warn("DT missing boot CPU MPIDR[23:0], fall back to default cpu_logical_map\n");
172 * Since the boot CPU node contains proper data, and all nodes have
173 * a reg property, the DT CPU list can be considered valid and the
174 * logical map created in smp_setup_processor_id() can be overridden
176 for (i = 0; i < cpuidx; i++) {
177 set_cpu_possible(i, true);
178 cpu_logical_map(i) = tmp_map[i];
179 pr_debug("cpu logical map 0x%x\n", cpu_logical_map(i));
183 bool arch_match_cpu_phys_id(int cpu, u64 phys_id)
185 return phys_id == cpu_logical_map(cpu);
188 static const void * __init arch_get_next_mach(const char *const **match)
190 static const struct machine_desc *mdesc = __arch_info_begin;
191 const struct machine_desc *m = mdesc;
193 if (m >= __arch_info_end)
197 *match = m->dt_compat;
202 * setup_machine_fdt - Machine setup when an dtb was passed to the kernel
203 * @dt_phys: physical address of dt blob
205 * If a dtb was passed to the kernel in r2, then use it to choose the
206 * correct machine_desc and to setup the system.
208 const struct machine_desc * __init setup_machine_fdt(unsigned int dt_phys)
210 const struct machine_desc *mdesc, *mdesc_best = NULL;
212 #ifdef CONFIG_ARCH_MULTIPLATFORM
213 DT_MACHINE_START(GENERIC_DT, "Generic DT based system")
216 mdesc_best = &__mach_desc_GENERIC_DT;
219 if (!dt_phys || !early_init_dt_scan(phys_to_virt(dt_phys)))
222 mdesc = of_flat_dt_match_machine(mdesc_best, arch_get_next_mach);
227 unsigned long dt_root;
229 early_print("\nError: unrecognized/unsupported "
230 "device tree compatible list:\n[ ");
232 dt_root = of_get_flat_dt_root();
233 prop = of_get_flat_dt_prop(dt_root, "compatible", &size);
235 early_print("'%s' ", prop);
236 size -= strlen(prop) + 1;
237 prop += strlen(prop) + 1;
239 early_print("]\n\n");
241 dump_machine_table(); /* does not return */
244 /* Change machine number to match the mdesc we're using */
245 __machine_arch_type = mdesc->nr;