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] = MPIDR_INVALID }; 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 if (of_node_cmp(cpu->type, "cpu")) 96 continue; 97 98 pr_debug(" * %s...\n", cpu->full_name); 99 /* 100 * A device tree containing CPU nodes with missing "reg" 101 * properties is considered invalid to build the 102 * cpu_logical_map. 103 */ 104 if (of_property_read_u32(cpu, "reg", &hwid)) { 105 pr_debug(" * %s missing reg property\n", 106 cpu->full_name); 107 return; 108 } 109 110 /* 111 * 8 MSBs must be set to 0 in the DT since the reg property 112 * defines the MPIDR[23:0]. 113 */ 114 if (hwid & ~MPIDR_HWID_BITMASK) 115 return; 116 117 /* 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. 123 */ 124 for (j = 0; j < cpuidx; j++) 125 if (WARN(tmp_map[j] == hwid, "Duplicate /cpu reg " 126 "properties in the DT\n")) 127 return; 128 129 /* 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(). 137 */ 138 if (hwid == mpidr) { 139 i = 0; 140 bootcpu_valid = true; 141 } else { 142 i = cpuidx++; 143 } 144 145 if (WARN(cpuidx > nr_cpu_ids, "DT /cpu %u nodes greater than " 146 "max cores %u, capping them\n", 147 cpuidx, nr_cpu_ids)) { 148 cpuidx = nr_cpu_ids; 149 break; 150 } 151 152 tmp_map[i] = hwid; 153 } 154 155 if (!bootcpu_valid) { 156 pr_warn("DT missing boot CPU MPIDR[23:0], fall back to default cpu_logical_map\n"); 157 return; 158 } 159 160 /* 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 164 */ 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)); 169 } 170 } 171 172 bool arch_match_cpu_phys_id(int cpu, u64 phys_id) 173 { 174 return (phys_id & MPIDR_HWID_BITMASK) == cpu_logical_map(cpu); 175 } 176 177 static const void * __init arch_get_next_mach(const char *const **match) 178 { 179 static const struct machine_desc *mdesc = __arch_info_begin; 180 const struct machine_desc *m = mdesc; 181 182 if (m >= __arch_info_end) 183 return NULL; 184 185 mdesc++; 186 *match = m->dt_compat; 187 return m; 188 } 189 190 /** 191 * setup_machine_fdt - Machine setup when an dtb was passed to the kernel 192 * @dt_phys: physical address of dt blob 193 * 194 * If a dtb was passed to the kernel in r2, then use it to choose the 195 * correct machine_desc and to setup the system. 196 */ 197 const struct machine_desc * __init setup_machine_fdt(unsigned int dt_phys) 198 { 199 const struct machine_desc *mdesc, *mdesc_best = NULL; 200 201 #ifdef CONFIG_ARCH_MULTIPLATFORM 202 DT_MACHINE_START(GENERIC_DT, "Generic DT based system") 203 MACHINE_END 204 205 mdesc_best = &__mach_desc_GENERIC_DT; 206 #endif 207 208 if (!dt_phys || !early_init_dt_scan(phys_to_virt(dt_phys))) 209 return NULL; 210 211 mdesc = of_flat_dt_match_machine(mdesc_best, arch_get_next_mach); 212 213 if (!mdesc) { 214 const char *prop; 215 long size; 216 unsigned long dt_root; 217 218 early_print("\nError: unrecognized/unsupported " 219 "device tree compatible list:\n[ "); 220 221 dt_root = of_get_flat_dt_root(); 222 prop = of_get_flat_dt_prop(dt_root, "compatible", &size); 223 while (size > 0) { 224 early_print("'%s' ", prop); 225 size -= strlen(prop) + 1; 226 prop += strlen(prop) + 1; 227 } 228 early_print("]\n\n"); 229 230 dump_machine_table(); /* does not return */ 231 } 232 233 /* Change machine number to match the mdesc we're using */ 234 __machine_arch_type = mdesc->nr; 235 236 return mdesc; 237 } 238