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 22 #include <asm/cputype.h> 23 #include <asm/setup.h> 24 #include <asm/page.h> 25 #include <asm/smp_plat.h> 26 #include <asm/mach/arch.h> 27 #include <asm/mach-types.h> 28 29 void __init early_init_dt_add_memory_arch(u64 base, u64 size) 30 { 31 arm_add_memory(base, size); 32 } 33 34 void * __init early_init_dt_alloc_memory_arch(u64 size, u64 align) 35 { 36 return alloc_bootmem_align(size, align); 37 } 38 39 void __init arm_dt_memblock_reserve(void) 40 { 41 u64 *reserve_map, base, size; 42 43 if (!initial_boot_params) 44 return; 45 46 /* Reserve the dtb region */ 47 memblock_reserve(virt_to_phys(initial_boot_params), 48 be32_to_cpu(initial_boot_params->totalsize)); 49 50 /* 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 54 */ 55 reserve_map = ((void*)initial_boot_params) + 56 be32_to_cpu(initial_boot_params->off_mem_rsvmap); 57 while (1) { 58 base = be64_to_cpup(reserve_map++); 59 size = be64_to_cpup(reserve_map++); 60 if (!size) 61 break; 62 memblock_reserve(base, size); 63 } 64 } 65 66 /* 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 69 * logical cpus 70 * 71 * Updates the cpu possible mask with the number of parsed cpu nodes 72 */ 73 void __init arm_dt_init_cpu_maps(void) 74 { 75 /* 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 79 * read as 0. 80 */ 81 struct device_node *cpu, *cpus; 82 u32 i, j, cpuidx = 1; 83 u32 mpidr = is_smp() ? read_cpuid_mpidr() & MPIDR_HWID_BITMASK : 0; 84 85 u32 tmp_map[NR_CPUS] = { [0 ... NR_CPUS-1] = UINT_MAX }; 86 bool bootcpu_valid = false; 87 cpus = of_find_node_by_path("/cpus"); 88 89 if (!cpus) 90 return; 91 92 for_each_child_of_node(cpus, cpu) { 93 u32 hwid; 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 return; 105 } 106 107 /* 108 * 8 MSBs must be set to 0 in the DT since the reg property 109 * defines the MPIDR[23:0]. 110 */ 111 if (hwid & ~MPIDR_HWID_BITMASK) 112 return; 113 114 /* 115 * Duplicate MPIDRs are a recipe for disaster. 116 * Scan all initialized entries and check for 117 * duplicates. If any is found just bail out. 118 * temp values were initialized to UINT_MAX 119 * to avoid matching valid MPIDR[23:0] values. 120 */ 121 for (j = 0; j < cpuidx; j++) 122 if (WARN(tmp_map[j] == hwid, "Duplicate /cpu reg " 123 "properties in the DT\n")) 124 return; 125 126 /* 127 * Build a stashed array of MPIDR values. Numbering scheme 128 * requires that if detected the boot CPU must be assigned 129 * logical id 0. Other CPUs get sequential indexes starting 130 * from 1. If a CPU node with a reg property matching the 131 * boot CPU MPIDR is detected, this is recorded so that the 132 * logical map built from DT is validated and can be used 133 * to override the map created in smp_setup_processor_id(). 134 */ 135 if (hwid == mpidr) { 136 i = 0; 137 bootcpu_valid = true; 138 } else { 139 i = cpuidx++; 140 } 141 142 if (WARN(cpuidx > nr_cpu_ids, "DT /cpu %u nodes greater than " 143 "max cores %u, capping them\n", 144 cpuidx, nr_cpu_ids)) { 145 cpuidx = nr_cpu_ids; 146 break; 147 } 148 149 tmp_map[i] = hwid; 150 } 151 152 if (WARN(!bootcpu_valid, "DT missing boot CPU MPIDR[23:0], " 153 "fall back to default cpu_logical_map\n")) 154 return; 155 156 /* 157 * Since the boot CPU node contains proper data, and all nodes have 158 * a reg property, the DT CPU list can be considered valid and the 159 * logical map created in smp_setup_processor_id() can be overridden 160 */ 161 for (i = 0; i < cpuidx; i++) { 162 set_cpu_possible(i, true); 163 cpu_logical_map(i) = tmp_map[i]; 164 pr_debug("cpu logical map 0x%x\n", cpu_logical_map(i)); 165 } 166 } 167 168 /** 169 * setup_machine_fdt - Machine setup when an dtb was passed to the kernel 170 * @dt_phys: physical address of dt blob 171 * 172 * If a dtb was passed to the kernel in r2, then use it to choose the 173 * correct machine_desc and to setup the system. 174 */ 175 struct machine_desc * __init setup_machine_fdt(unsigned int dt_phys) 176 { 177 struct boot_param_header *devtree; 178 struct machine_desc *mdesc, *mdesc_best = NULL; 179 unsigned int score, mdesc_score = ~1; 180 unsigned long dt_root; 181 const char *model; 182 183 if (!dt_phys) 184 return NULL; 185 186 devtree = phys_to_virt(dt_phys); 187 188 /* check device tree validity */ 189 if (be32_to_cpu(devtree->magic) != OF_DT_HEADER) 190 return NULL; 191 192 /* Search the mdescs for the 'best' compatible value match */ 193 initial_boot_params = devtree; 194 dt_root = of_get_flat_dt_root(); 195 for_each_machine_desc(mdesc) { 196 score = of_flat_dt_match(dt_root, mdesc->dt_compat); 197 if (score > 0 && score < mdesc_score) { 198 mdesc_best = mdesc; 199 mdesc_score = score; 200 } 201 } 202 if (!mdesc_best) { 203 const char *prop; 204 long size; 205 206 early_print("\nError: unrecognized/unsupported " 207 "device tree compatible list:\n[ "); 208 209 prop = of_get_flat_dt_prop(dt_root, "compatible", &size); 210 while (size > 0) { 211 early_print("'%s' ", prop); 212 size -= strlen(prop) + 1; 213 prop += strlen(prop) + 1; 214 } 215 early_print("]\n\n"); 216 217 dump_machine_table(); /* does not return */ 218 } 219 220 model = of_get_flat_dt_prop(dt_root, "model", NULL); 221 if (!model) 222 model = of_get_flat_dt_prop(dt_root, "compatible", NULL); 223 if (!model) 224 model = "<unknown>"; 225 pr_info("Machine: %s, model: %s\n", mdesc_best->name, model); 226 227 /* Retrieve various information from the /chosen node */ 228 of_scan_flat_dt(early_init_dt_scan_chosen, boot_command_line); 229 /* Initialize {size,address}-cells info */ 230 of_scan_flat_dt(early_init_dt_scan_root, NULL); 231 /* Setup memory, calling early_init_dt_add_memory_arch */ 232 of_scan_flat_dt(early_init_dt_scan_memory, NULL); 233 234 /* Change machine number to match the mdesc we're using */ 235 __machine_arch_type = mdesc_best->nr; 236 237 return mdesc_best; 238 } 239