1 // SPDX-License-Identifier: GPL-2.0-only 2 /* 3 * Based on arch/arm/kernel/setup.c 4 * 5 * Copyright (C) 1995-2001 Russell King 6 * Copyright (C) 2012 ARM Ltd. 7 */ 8 9 #include <linux/acpi.h> 10 #include <linux/export.h> 11 #include <linux/kernel.h> 12 #include <linux/stddef.h> 13 #include <linux/ioport.h> 14 #include <linux/delay.h> 15 #include <linux/initrd.h> 16 #include <linux/console.h> 17 #include <linux/cache.h> 18 #include <linux/screen_info.h> 19 #include <linux/init.h> 20 #include <linux/kexec.h> 21 #include <linux/root_dev.h> 22 #include <linux/cpu.h> 23 #include <linux/interrupt.h> 24 #include <linux/smp.h> 25 #include <linux/fs.h> 26 #include <linux/proc_fs.h> 27 #include <linux/memblock.h> 28 #include <linux/of_fdt.h> 29 #include <linux/efi.h> 30 #include <linux/psci.h> 31 #include <linux/sched/task.h> 32 #include <linux/mm.h> 33 34 #include <asm/acpi.h> 35 #include <asm/fixmap.h> 36 #include <asm/cpu.h> 37 #include <asm/cputype.h> 38 #include <asm/daifflags.h> 39 #include <asm/elf.h> 40 #include <asm/cpufeature.h> 41 #include <asm/cpu_ops.h> 42 #include <asm/kasan.h> 43 #include <asm/numa.h> 44 #include <asm/sections.h> 45 #include <asm/setup.h> 46 #include <asm/smp_plat.h> 47 #include <asm/cacheflush.h> 48 #include <asm/tlbflush.h> 49 #include <asm/traps.h> 50 #include <asm/efi.h> 51 #include <asm/xen/hypervisor.h> 52 #include <asm/mmu_context.h> 53 54 static int num_standard_resources; 55 static struct resource *standard_resources; 56 57 phys_addr_t __fdt_pointer __initdata; 58 59 /* 60 * Standard memory resources 61 */ 62 static struct resource mem_res[] = { 63 { 64 .name = "Kernel code", 65 .start = 0, 66 .end = 0, 67 .flags = IORESOURCE_SYSTEM_RAM 68 }, 69 { 70 .name = "Kernel data", 71 .start = 0, 72 .end = 0, 73 .flags = IORESOURCE_SYSTEM_RAM 74 } 75 }; 76 77 #define kernel_code mem_res[0] 78 #define kernel_data mem_res[1] 79 80 /* 81 * The recorded values of x0 .. x3 upon kernel entry. 82 */ 83 u64 __cacheline_aligned boot_args[4]; 84 85 void __init smp_setup_processor_id(void) 86 { 87 u64 mpidr = read_cpuid_mpidr() & MPIDR_HWID_BITMASK; 88 cpu_logical_map(0) = mpidr; 89 90 /* 91 * clear __my_cpu_offset on boot CPU to avoid hang caused by 92 * using percpu variable early, for example, lockdep will 93 * access percpu variable inside lock_release 94 */ 95 set_my_cpu_offset(0); 96 pr_info("Booting Linux on physical CPU 0x%010lx [0x%08x]\n", 97 (unsigned long)mpidr, read_cpuid_id()); 98 } 99 100 bool arch_match_cpu_phys_id(int cpu, u64 phys_id) 101 { 102 return phys_id == cpu_logical_map(cpu); 103 } 104 105 struct mpidr_hash mpidr_hash; 106 /** 107 * smp_build_mpidr_hash - Pre-compute shifts required at each affinity 108 * level in order to build a linear index from an 109 * MPIDR value. Resulting algorithm is a collision 110 * free hash carried out through shifting and ORing 111 */ 112 static void __init smp_build_mpidr_hash(void) 113 { 114 u32 i, affinity, fs[4], bits[4], ls; 115 u64 mask = 0; 116 /* 117 * Pre-scan the list of MPIDRS and filter out bits that do 118 * not contribute to affinity levels, ie they never toggle. 119 */ 120 for_each_possible_cpu(i) 121 mask |= (cpu_logical_map(i) ^ cpu_logical_map(0)); 122 pr_debug("mask of set bits %#llx\n", mask); 123 /* 124 * Find and stash the last and first bit set at all affinity levels to 125 * check how many bits are required to represent them. 126 */ 127 for (i = 0; i < 4; i++) { 128 affinity = MPIDR_AFFINITY_LEVEL(mask, i); 129 /* 130 * Find the MSB bit and LSB bits position 131 * to determine how many bits are required 132 * to express the affinity level. 133 */ 134 ls = fls(affinity); 135 fs[i] = affinity ? ffs(affinity) - 1 : 0; 136 bits[i] = ls - fs[i]; 137 } 138 /* 139 * An index can be created from the MPIDR_EL1 by isolating the 140 * significant bits at each affinity level and by shifting 141 * them in order to compress the 32 bits values space to a 142 * compressed set of values. This is equivalent to hashing 143 * the MPIDR_EL1 through shifting and ORing. It is a collision free 144 * hash though not minimal since some levels might contain a number 145 * of CPUs that is not an exact power of 2 and their bit 146 * representation might contain holes, eg MPIDR_EL1[7:0] = {0x2, 0x80}. 147 */ 148 mpidr_hash.shift_aff[0] = MPIDR_LEVEL_SHIFT(0) + fs[0]; 149 mpidr_hash.shift_aff[1] = MPIDR_LEVEL_SHIFT(1) + fs[1] - bits[0]; 150 mpidr_hash.shift_aff[2] = MPIDR_LEVEL_SHIFT(2) + fs[2] - 151 (bits[1] + bits[0]); 152 mpidr_hash.shift_aff[3] = MPIDR_LEVEL_SHIFT(3) + 153 fs[3] - (bits[2] + bits[1] + bits[0]); 154 mpidr_hash.mask = mask; 155 mpidr_hash.bits = bits[3] + bits[2] + bits[1] + bits[0]; 156 pr_debug("MPIDR hash: aff0[%u] aff1[%u] aff2[%u] aff3[%u] mask[%#llx] bits[%u]\n", 157 mpidr_hash.shift_aff[0], 158 mpidr_hash.shift_aff[1], 159 mpidr_hash.shift_aff[2], 160 mpidr_hash.shift_aff[3], 161 mpidr_hash.mask, 162 mpidr_hash.bits); 163 /* 164 * 4x is an arbitrary value used to warn on a hash table much bigger 165 * than expected on most systems. 166 */ 167 if (mpidr_hash_size() > 4 * num_possible_cpus()) 168 pr_warn("Large number of MPIDR hash buckets detected\n"); 169 } 170 171 static void __init setup_machine_fdt(phys_addr_t dt_phys) 172 { 173 int size; 174 void *dt_virt = fixmap_remap_fdt(dt_phys, &size, PAGE_KERNEL); 175 const char *name; 176 177 if (dt_virt) 178 memblock_reserve(dt_phys, size); 179 180 if (!dt_virt || !early_init_dt_scan(dt_virt)) { 181 pr_crit("\n" 182 "Error: invalid device tree blob at physical address %pa (virtual address 0x%p)\n" 183 "The dtb must be 8-byte aligned and must not exceed 2 MB in size\n" 184 "\nPlease check your bootloader.", 185 &dt_phys, dt_virt); 186 187 while (true) 188 cpu_relax(); 189 } 190 191 /* Early fixups are done, map the FDT as read-only now */ 192 fixmap_remap_fdt(dt_phys, &size, PAGE_KERNEL_RO); 193 194 name = of_flat_dt_get_machine_name(); 195 if (!name) 196 return; 197 198 pr_info("Machine model: %s\n", name); 199 dump_stack_set_arch_desc("%s (DT)", name); 200 } 201 202 static void __init request_standard_resources(void) 203 { 204 struct memblock_region *region; 205 struct resource *res; 206 unsigned long i = 0; 207 size_t res_size; 208 209 kernel_code.start = __pa_symbol(_text); 210 kernel_code.end = __pa_symbol(__init_begin - 1); 211 kernel_data.start = __pa_symbol(_sdata); 212 kernel_data.end = __pa_symbol(_end - 1); 213 214 num_standard_resources = memblock.memory.cnt; 215 res_size = num_standard_resources * sizeof(*standard_resources); 216 standard_resources = memblock_alloc(res_size, SMP_CACHE_BYTES); 217 if (!standard_resources) 218 panic("%s: Failed to allocate %zu bytes\n", __func__, res_size); 219 220 for_each_memblock(memory, region) { 221 res = &standard_resources[i++]; 222 if (memblock_is_nomap(region)) { 223 res->name = "reserved"; 224 res->flags = IORESOURCE_MEM; 225 } else { 226 res->name = "System RAM"; 227 res->flags = IORESOURCE_SYSTEM_RAM | IORESOURCE_BUSY; 228 } 229 res->start = __pfn_to_phys(memblock_region_memory_base_pfn(region)); 230 res->end = __pfn_to_phys(memblock_region_memory_end_pfn(region)) - 1; 231 232 request_resource(&iomem_resource, res); 233 234 if (kernel_code.start >= res->start && 235 kernel_code.end <= res->end) 236 request_resource(res, &kernel_code); 237 if (kernel_data.start >= res->start && 238 kernel_data.end <= res->end) 239 request_resource(res, &kernel_data); 240 #ifdef CONFIG_KEXEC_CORE 241 /* Userspace will find "Crash kernel" region in /proc/iomem. */ 242 if (crashk_res.end && crashk_res.start >= res->start && 243 crashk_res.end <= res->end) 244 request_resource(res, &crashk_res); 245 #endif 246 } 247 } 248 249 static int __init reserve_memblock_reserved_regions(void) 250 { 251 u64 i, j; 252 253 for (i = 0; i < num_standard_resources; ++i) { 254 struct resource *mem = &standard_resources[i]; 255 phys_addr_t r_start, r_end, mem_size = resource_size(mem); 256 257 if (!memblock_is_region_reserved(mem->start, mem_size)) 258 continue; 259 260 for_each_reserved_mem_region(j, &r_start, &r_end) { 261 resource_size_t start, end; 262 263 start = max(PFN_PHYS(PFN_DOWN(r_start)), mem->start); 264 end = min(PFN_PHYS(PFN_UP(r_end)) - 1, mem->end); 265 266 if (start > mem->end || end < mem->start) 267 continue; 268 269 reserve_region_with_split(mem, start, end, "reserved"); 270 } 271 } 272 273 return 0; 274 } 275 arch_initcall(reserve_memblock_reserved_regions); 276 277 u64 __cpu_logical_map[NR_CPUS] = { [0 ... NR_CPUS-1] = INVALID_HWID }; 278 279 void __init setup_arch(char **cmdline_p) 280 { 281 init_mm.start_code = (unsigned long) _text; 282 init_mm.end_code = (unsigned long) _etext; 283 init_mm.end_data = (unsigned long) _edata; 284 init_mm.brk = (unsigned long) _end; 285 286 *cmdline_p = boot_command_line; 287 288 /* 289 * If know now we are going to need KPTI then use non-global 290 * mappings from the start, avoiding the cost of rewriting 291 * everything later. 292 */ 293 arm64_use_ng_mappings = kaslr_requires_kpti(); 294 295 early_fixmap_init(); 296 early_ioremap_init(); 297 298 setup_machine_fdt(__fdt_pointer); 299 300 /* 301 * Initialise the static keys early as they may be enabled by the 302 * cpufeature code and early parameters. 303 */ 304 jump_label_init(); 305 parse_early_param(); 306 307 /* 308 * Unmask asynchronous aborts and fiq after bringing up possible 309 * earlycon. (Report possible System Errors once we can report this 310 * occurred). 311 */ 312 local_daif_restore(DAIF_PROCCTX_NOIRQ); 313 314 /* 315 * TTBR0 is only used for the identity mapping at this stage. Make it 316 * point to zero page to avoid speculatively fetching new entries. 317 */ 318 cpu_uninstall_idmap(); 319 320 xen_early_init(); 321 efi_init(); 322 arm64_memblock_init(); 323 324 paging_init(); 325 326 acpi_table_upgrade(); 327 328 /* Parse the ACPI tables for possible boot-time configuration */ 329 acpi_boot_table_init(); 330 331 if (acpi_disabled) 332 unflatten_device_tree(); 333 334 bootmem_init(); 335 336 kasan_init(); 337 338 request_standard_resources(); 339 340 early_ioremap_reset(); 341 342 if (acpi_disabled) 343 psci_dt_init(); 344 else 345 psci_acpi_init(); 346 347 init_bootcpu_ops(); 348 smp_init_cpus(); 349 smp_build_mpidr_hash(); 350 351 /* Init percpu seeds for random tags after cpus are set up. */ 352 kasan_init_tags(); 353 354 #ifdef CONFIG_ARM64_SW_TTBR0_PAN 355 /* 356 * Make sure init_thread_info.ttbr0 always generates translation 357 * faults in case uaccess_enable() is inadvertently called by the init 358 * thread. 359 */ 360 init_task.thread_info.ttbr0 = __pa_symbol(empty_zero_page); 361 #endif 362 363 if (boot_args[1] || boot_args[2] || boot_args[3]) { 364 pr_err("WARNING: x1-x3 nonzero in violation of boot protocol:\n" 365 "\tx1: %016llx\n\tx2: %016llx\n\tx3: %016llx\n" 366 "This indicates a broken bootloader or old kernel\n", 367 boot_args[1], boot_args[2], boot_args[3]); 368 } 369 } 370 371 static inline bool cpu_can_disable(unsigned int cpu) 372 { 373 #ifdef CONFIG_HOTPLUG_CPU 374 const struct cpu_operations *ops = get_cpu_ops(cpu); 375 376 if (ops && ops->cpu_can_disable) 377 return ops->cpu_can_disable(cpu); 378 #endif 379 return false; 380 } 381 382 static int __init topology_init(void) 383 { 384 int i; 385 386 for_each_online_node(i) 387 register_one_node(i); 388 389 for_each_possible_cpu(i) { 390 struct cpu *cpu = &per_cpu(cpu_data.cpu, i); 391 cpu->hotpluggable = cpu_can_disable(i); 392 register_cpu(cpu, i); 393 } 394 395 return 0; 396 } 397 subsys_initcall(topology_init); 398 399 /* 400 * Dump out kernel offset information on panic. 401 */ 402 static int dump_kernel_offset(struct notifier_block *self, unsigned long v, 403 void *p) 404 { 405 const unsigned long offset = kaslr_offset(); 406 407 if (IS_ENABLED(CONFIG_RANDOMIZE_BASE) && offset > 0) { 408 pr_emerg("Kernel Offset: 0x%lx from 0x%lx\n", 409 offset, KIMAGE_VADDR); 410 pr_emerg("PHYS_OFFSET: 0x%llx\n", PHYS_OFFSET); 411 } else { 412 pr_emerg("Kernel Offset: disabled\n"); 413 } 414 return 0; 415 } 416 417 static struct notifier_block kernel_offset_notifier = { 418 .notifier_call = dump_kernel_offset 419 }; 420 421 static int __init register_kernel_offset_dumper(void) 422 { 423 atomic_notifier_chain_register(&panic_notifier_list, 424 &kernel_offset_notifier); 425 return 0; 426 } 427 __initcall(register_kernel_offset_dumper); 428