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_alloc_memory_arch(u64 size, u64 align)
32 return memblock_virt_alloc(size, align);
35 void __init arm_dt_memblock_reserve(void)
37 u64 *reserve_map, base, size;
39 if (!initial_boot_params)
42 /* Reserve the dtb region */
43 memblock_reserve(virt_to_phys(initial_boot_params),
44 be32_to_cpu(initial_boot_params->totalsize));
47 * Process the reserve map. This will probably overlap the initrd
48 * and dtb locations which are already reserved, but overlaping
49 * doesn't hurt anything
51 reserve_map = ((void*)initial_boot_params) +
52 be32_to_cpu(initial_boot_params->off_mem_rsvmap);
54 base = be64_to_cpup(reserve_map++);
55 size = be64_to_cpup(reserve_map++);
58 memblock_reserve(base, size);
63 extern struct of_cpu_method __cpu_method_of_table_begin[];
64 extern struct of_cpu_method __cpu_method_of_table_end[];
66 static int __init set_smp_ops_by_method(struct device_node *node)
69 struct of_cpu_method *m = __cpu_method_of_table_begin;
71 if (of_property_read_string(node, "enable-method", &method))
74 for (; m < __cpu_method_of_table_end; m++)
75 if (!strcmp(m->method, method)) {
83 static inline int set_smp_ops_by_method(struct device_node *node)
91 * arm_dt_init_cpu_maps - Function retrieves cpu nodes from the device tree
92 * and builds the cpu logical map array containing MPIDR values related to
95 * Updates the cpu possible mask with the number of parsed cpu nodes
97 void __init arm_dt_init_cpu_maps(void)
100 * Temp logical map is initialized with UINT_MAX values that are
101 * considered invalid logical map entries since the logical map must
102 * contain a list of MPIDR[23:0] values where MPIDR[31:24] must
105 struct device_node *cpu, *cpus;
106 int found_method = 0;
107 u32 i, j, cpuidx = 1;
108 u32 mpidr = is_smp() ? read_cpuid_mpidr() & MPIDR_HWID_BITMASK : 0;
110 u32 tmp_map[NR_CPUS] = { [0 ... NR_CPUS-1] = MPIDR_INVALID };
111 bool bootcpu_valid = false;
112 cpus = of_find_node_by_path("/cpus");
117 for_each_child_of_node(cpus, cpu) {
120 if (of_node_cmp(cpu->type, "cpu"))
123 pr_debug(" * %s...\n", cpu->full_name);
125 * A device tree containing CPU nodes with missing "reg"
126 * properties is considered invalid to build the
129 if (of_property_read_u32(cpu, "reg", &hwid)) {
130 pr_debug(" * %s missing reg property\n",
136 * 8 MSBs must be set to 0 in the DT since the reg property
137 * defines the MPIDR[23:0].
139 if (hwid & ~MPIDR_HWID_BITMASK)
143 * Duplicate MPIDRs are a recipe for disaster.
144 * Scan all initialized entries and check for
145 * duplicates. If any is found just bail out.
146 * temp values were initialized to UINT_MAX
147 * to avoid matching valid MPIDR[23:0] values.
149 for (j = 0; j < cpuidx; j++)
150 if (WARN(tmp_map[j] == hwid, "Duplicate /cpu reg "
151 "properties in the DT\n"))
155 * Build a stashed array of MPIDR values. Numbering scheme
156 * requires that if detected the boot CPU must be assigned
157 * logical id 0. Other CPUs get sequential indexes starting
158 * from 1. If a CPU node with a reg property matching the
159 * boot CPU MPIDR is detected, this is recorded so that the
160 * logical map built from DT is validated and can be used
161 * to override the map created in smp_setup_processor_id().
165 bootcpu_valid = true;
170 if (WARN(cpuidx > nr_cpu_ids, "DT /cpu %u nodes greater than "
171 "max cores %u, capping them\n",
172 cpuidx, nr_cpu_ids)) {
180 found_method = set_smp_ops_by_method(cpu);
184 * Fallback to an enable-method in the cpus node if nothing found in
188 set_smp_ops_by_method(cpus);
190 if (!bootcpu_valid) {
191 pr_warn("DT missing boot CPU MPIDR[23:0], fall back to default cpu_logical_map\n");
196 * Since the boot CPU node contains proper data, and all nodes have
197 * a reg property, the DT CPU list can be considered valid and the
198 * logical map created in smp_setup_processor_id() can be overridden
200 for (i = 0; i < cpuidx; i++) {
201 set_cpu_possible(i, true);
202 cpu_logical_map(i) = tmp_map[i];
203 pr_debug("cpu logical map 0x%x\n", cpu_logical_map(i));
207 bool arch_match_cpu_phys_id(int cpu, u64 phys_id)
209 return phys_id == cpu_logical_map(cpu);
212 static const void * __init arch_get_next_mach(const char *const **match)
214 static const struct machine_desc *mdesc = __arch_info_begin;
215 const struct machine_desc *m = mdesc;
217 if (m >= __arch_info_end)
221 *match = m->dt_compat;
226 * setup_machine_fdt - Machine setup when an dtb was passed to the kernel
227 * @dt_phys: physical address of dt blob
229 * If a dtb was passed to the kernel in r2, then use it to choose the
230 * correct machine_desc and to setup the system.
232 const struct machine_desc * __init setup_machine_fdt(unsigned int dt_phys)
234 const struct machine_desc *mdesc, *mdesc_best = NULL;
236 #ifdef CONFIG_ARCH_MULTIPLATFORM
237 DT_MACHINE_START(GENERIC_DT, "Generic DT based system")
240 mdesc_best = &__mach_desc_GENERIC_DT;
243 if (!dt_phys || !early_init_dt_scan(phys_to_virt(dt_phys)))
246 mdesc = of_flat_dt_match_machine(mdesc_best, arch_get_next_mach);
251 unsigned long dt_root;
253 early_print("\nError: unrecognized/unsupported "
254 "device tree compatible list:\n[ ");
256 dt_root = of_get_flat_dt_root();
257 prop = of_get_flat_dt_prop(dt_root, "compatible", &size);
259 early_print("'%s' ", prop);
260 size -= strlen(prop) + 1;
261 prop += strlen(prop) + 1;
263 early_print("]\n\n");
265 dump_machine_table(); /* does not return */
268 /* Change machine number to match the mdesc we're using */
269 __machine_arch_type = mdesc->nr;