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>
22 #include <asm/cputype.h>
23 #include <asm/setup.h>
25 #include <asm/smp_plat.h>
26 #include <asm/mach/arch.h>
27 #include <asm/mach-types.h>
29 void __init early_init_dt_add_memory_arch(u64 base, u64 size)
31 arm_add_memory(base, size);
34 void * __init early_init_dt_alloc_memory_arch(u64 size, u64 align)
36 return alloc_bootmem_align(size, align);
39 void __init arm_dt_memblock_reserve(void)
41 u64 *reserve_map, base, size;
43 if (!initial_boot_params)
46 /* Reserve the dtb region */
47 memblock_reserve(virt_to_phys(initial_boot_params),
48 be32_to_cpu(initial_boot_params->totalsize));
51 * Process the reserve map. This will probably overlap the initrd
52 * and dtb locations which are already reserved, but overlaping
53 * doesn't hurt anything
55 reserve_map = ((void*)initial_boot_params) +
56 be32_to_cpu(initial_boot_params->off_mem_rsvmap);
58 base = be64_to_cpup(reserve_map++);
59 size = be64_to_cpup(reserve_map++);
62 memblock_reserve(base, size);
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;
83 u32 mpidr = is_smp() ? read_cpuid_mpidr() & MPIDR_HWID_BITMASK : 0;
85 u32 tmp_map[NR_CPUS] = { [0 ... NR_CPUS-1] = MPIDR_INVALID };
86 bool bootcpu_valid = false;
87 cpus = of_find_node_by_path("/cpus");
92 for_each_child_of_node(cpus, cpu) {
95 if (of_node_cmp(cpu->type, "cpu"))
98 pr_debug(" * %s...\n", cpu->full_name);
100 * A device tree containing CPU nodes with missing "reg"
101 * properties is considered invalid to build the
104 if (of_property_read_u32(cpu, "reg", &hwid)) {
105 pr_debug(" * %s missing reg property\n",
111 * 8 MSBs must be set to 0 in the DT since the reg property
112 * defines the MPIDR[23:0].
114 if (hwid & ~MPIDR_HWID_BITMASK)
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.
124 for (j = 0; j < cpuidx; j++)
125 if (WARN(tmp_map[j] == hwid, "Duplicate /cpu reg "
126 "properties in the DT\n"))
130 * Build a stashed array of MPIDR values. Numbering scheme
131 * requires that if detected the boot CPU must be assigned
132 * logical id 0. Other CPUs get sequential indexes starting
133 * from 1. If a CPU node with a reg property matching the
134 * boot CPU MPIDR is detected, this is recorded so that the
135 * logical map built from DT is validated and can be used
136 * to override the map created in smp_setup_processor_id().
140 bootcpu_valid = true;
145 if (WARN(cpuidx > nr_cpu_ids, "DT /cpu %u nodes greater than "
146 "max cores %u, capping them\n",
147 cpuidx, nr_cpu_ids)) {
155 if (!bootcpu_valid) {
156 pr_warn("DT missing boot CPU MPIDR[23:0], fall back to default cpu_logical_map\n");
161 * Since the boot CPU node contains proper data, and all nodes have
162 * a reg property, the DT CPU list can be considered valid and the
163 * logical map created in smp_setup_processor_id() can be overridden
165 for (i = 0; i < cpuidx; i++) {
166 set_cpu_possible(i, true);
167 cpu_logical_map(i) = tmp_map[i];
168 pr_debug("cpu logical map 0x%x\n", cpu_logical_map(i));
173 * setup_machine_fdt - Machine setup when an dtb was passed to the kernel
174 * @dt_phys: physical address of dt blob
176 * If a dtb was passed to the kernel in r2, then use it to choose the
177 * correct machine_desc and to setup the system.
179 const struct machine_desc * __init setup_machine_fdt(unsigned int dt_phys)
181 struct boot_param_header *devtree;
182 const struct machine_desc *mdesc, *mdesc_best = NULL;
183 unsigned int score, mdesc_score = ~1;
184 unsigned long dt_root;
187 #ifdef CONFIG_ARCH_MULTIPLATFORM
188 DT_MACHINE_START(GENERIC_DT, "Generic DT based system")
191 mdesc_best = &__mach_desc_GENERIC_DT;
197 devtree = phys_to_virt(dt_phys);
199 /* check device tree validity */
200 if (be32_to_cpu(devtree->magic) != OF_DT_HEADER)
203 /* Search the mdescs for the 'best' compatible value match */
204 initial_boot_params = devtree;
205 dt_root = of_get_flat_dt_root();
206 for_each_machine_desc(mdesc) {
207 score = of_flat_dt_match(dt_root, mdesc->dt_compat);
208 if (score > 0 && score < mdesc_score) {
217 early_print("\nError: unrecognized/unsupported "
218 "device tree compatible list:\n[ ");
220 prop = of_get_flat_dt_prop(dt_root, "compatible", &size);
222 early_print("'%s' ", prop);
223 size -= strlen(prop) + 1;
224 prop += strlen(prop) + 1;
226 early_print("]\n\n");
228 dump_machine_table(); /* does not return */
231 model = of_get_flat_dt_prop(dt_root, "model", NULL);
233 model = of_get_flat_dt_prop(dt_root, "compatible", NULL);
236 pr_info("Machine: %s, model: %s\n", mdesc_best->name, model);
238 /* Retrieve various information from the /chosen node */
239 of_scan_flat_dt(early_init_dt_scan_chosen, boot_command_line);
240 /* Initialize {size,address}-cells info */
241 of_scan_flat_dt(early_init_dt_scan_root, NULL);
242 /* Setup memory, calling early_init_dt_add_memory_arch */
243 of_scan_flat_dt(early_init_dt_scan_memory, NULL);
245 /* Change machine number to match the mdesc we're using */
246 __machine_arch_type = mdesc_best->nr;