1 // SPDX-License-Identifier: GPL-2.0-only
3 * Based on arch/arm/kernel/setup.c
5 * Copyright (C) 1995-2001 Russell King
6 * Copyright (C) 2012 ARM Ltd.
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>
26 #include <linux/panic_notifier.h>
27 #include <linux/proc_fs.h>
28 #include <linux/memblock.h>
29 #include <linux/of_fdt.h>
30 #include <linux/efi.h>
31 #include <linux/psci.h>
32 #include <linux/sched/task.h>
36 #include <asm/fixmap.h>
38 #include <asm/cputype.h>
39 #include <asm/daifflags.h>
41 #include <asm/cpufeature.h>
42 #include <asm/cpu_ops.h>
43 #include <asm/kasan.h>
45 #include <asm/sections.h>
46 #include <asm/setup.h>
47 #include <asm/smp_plat.h>
48 #include <asm/cacheflush.h>
49 #include <asm/tlbflush.h>
50 #include <asm/traps.h>
52 #include <asm/xen/hypervisor.h>
53 #include <asm/mmu_context.h>
55 static int num_standard_resources;
56 static struct resource *standard_resources;
58 phys_addr_t __fdt_pointer __initdata;
61 * Standard memory resources
63 static struct resource mem_res[] = {
65 .name = "Kernel code",
68 .flags = IORESOURCE_SYSTEM_RAM
71 .name = "Kernel data",
74 .flags = IORESOURCE_SYSTEM_RAM
78 #define kernel_code mem_res[0]
79 #define kernel_data mem_res[1]
82 * The recorded values of x0 .. x3 upon kernel entry.
84 u64 __cacheline_aligned boot_args[4];
86 void __init smp_setup_processor_id(void)
88 u64 mpidr = read_cpuid_mpidr() & MPIDR_HWID_BITMASK;
89 set_cpu_logical_map(0, mpidr);
91 pr_info("Booting Linux on physical CPU 0x%010lx [0x%08x]\n",
92 (unsigned long)mpidr, read_cpuid_id());
95 bool arch_match_cpu_phys_id(int cpu, u64 phys_id)
97 return phys_id == cpu_logical_map(cpu);
100 struct mpidr_hash mpidr_hash;
102 * smp_build_mpidr_hash - Pre-compute shifts required at each affinity
103 * level in order to build a linear index from an
104 * MPIDR value. Resulting algorithm is a collision
105 * free hash carried out through shifting and ORing
107 static void __init smp_build_mpidr_hash(void)
109 u32 i, affinity, fs[4], bits[4], ls;
112 * Pre-scan the list of MPIDRS and filter out bits that do
113 * not contribute to affinity levels, ie they never toggle.
115 for_each_possible_cpu(i)
116 mask |= (cpu_logical_map(i) ^ cpu_logical_map(0));
117 pr_debug("mask of set bits %#llx\n", mask);
119 * Find and stash the last and first bit set at all affinity levels to
120 * check how many bits are required to represent them.
122 for (i = 0; i < 4; i++) {
123 affinity = MPIDR_AFFINITY_LEVEL(mask, i);
125 * Find the MSB bit and LSB bits position
126 * to determine how many bits are required
127 * to express the affinity level.
130 fs[i] = affinity ? ffs(affinity) - 1 : 0;
131 bits[i] = ls - fs[i];
134 * An index can be created from the MPIDR_EL1 by isolating the
135 * significant bits at each affinity level and by shifting
136 * them in order to compress the 32 bits values space to a
137 * compressed set of values. This is equivalent to hashing
138 * the MPIDR_EL1 through shifting and ORing. It is a collision free
139 * hash though not minimal since some levels might contain a number
140 * of CPUs that is not an exact power of 2 and their bit
141 * representation might contain holes, eg MPIDR_EL1[7:0] = {0x2, 0x80}.
143 mpidr_hash.shift_aff[0] = MPIDR_LEVEL_SHIFT(0) + fs[0];
144 mpidr_hash.shift_aff[1] = MPIDR_LEVEL_SHIFT(1) + fs[1] - bits[0];
145 mpidr_hash.shift_aff[2] = MPIDR_LEVEL_SHIFT(2) + fs[2] -
147 mpidr_hash.shift_aff[3] = MPIDR_LEVEL_SHIFT(3) +
148 fs[3] - (bits[2] + bits[1] + bits[0]);
149 mpidr_hash.mask = mask;
150 mpidr_hash.bits = bits[3] + bits[2] + bits[1] + bits[0];
151 pr_debug("MPIDR hash: aff0[%u] aff1[%u] aff2[%u] aff3[%u] mask[%#llx] bits[%u]\n",
152 mpidr_hash.shift_aff[0],
153 mpidr_hash.shift_aff[1],
154 mpidr_hash.shift_aff[2],
155 mpidr_hash.shift_aff[3],
159 * 4x is an arbitrary value used to warn on a hash table much bigger
160 * than expected on most systems.
162 if (mpidr_hash_size() > 4 * num_possible_cpus())
163 pr_warn("Large number of MPIDR hash buckets detected\n");
166 static void *early_fdt_ptr __initdata;
168 void __init *get_early_fdt_ptr(void)
170 return early_fdt_ptr;
173 asmlinkage void __init early_fdt_map(u64 dt_phys)
178 early_fdt_ptr = fixmap_remap_fdt(dt_phys, &fdt_size, PAGE_KERNEL);
181 static void __init setup_machine_fdt(phys_addr_t dt_phys)
184 void *dt_virt = fixmap_remap_fdt(dt_phys, &size, PAGE_KERNEL);
188 memblock_reserve(dt_phys, size);
190 if (!dt_virt || !early_init_dt_scan(dt_virt)) {
192 "Error: invalid device tree blob at physical address %pa (virtual address 0x%px)\n"
193 "The dtb must be 8-byte aligned and must not exceed 2 MB in size\n"
194 "\nPlease check your bootloader.",
198 * Note that in this _really_ early stage we cannot even BUG()
199 * or oops, so the least terrible thing to do is cpu_relax(),
200 * or else we could end-up printing non-initialized data, etc.
206 /* Early fixups are done, map the FDT as read-only now */
207 fixmap_remap_fdt(dt_phys, &size, PAGE_KERNEL_RO);
209 name = of_flat_dt_get_machine_name();
213 pr_info("Machine model: %s\n", name);
214 dump_stack_set_arch_desc("%s (DT)", name);
217 static void __init request_standard_resources(void)
219 struct memblock_region *region;
220 struct resource *res;
224 kernel_code.start = __pa_symbol(_stext);
225 kernel_code.end = __pa_symbol(__init_begin - 1);
226 kernel_data.start = __pa_symbol(_sdata);
227 kernel_data.end = __pa_symbol(_end - 1);
228 insert_resource(&iomem_resource, &kernel_code);
229 insert_resource(&iomem_resource, &kernel_data);
231 num_standard_resources = memblock.memory.cnt;
232 res_size = num_standard_resources * sizeof(*standard_resources);
233 standard_resources = memblock_alloc(res_size, SMP_CACHE_BYTES);
234 if (!standard_resources)
235 panic("%s: Failed to allocate %zu bytes\n", __func__, res_size);
237 for_each_mem_region(region) {
238 res = &standard_resources[i++];
239 if (memblock_is_nomap(region)) {
240 res->name = "reserved";
241 res->flags = IORESOURCE_MEM;
242 res->start = __pfn_to_phys(memblock_region_reserved_base_pfn(region));
243 res->end = __pfn_to_phys(memblock_region_reserved_end_pfn(region)) - 1;
245 res->name = "System RAM";
246 res->flags = IORESOURCE_SYSTEM_RAM | IORESOURCE_BUSY;
247 res->start = __pfn_to_phys(memblock_region_memory_base_pfn(region));
248 res->end = __pfn_to_phys(memblock_region_memory_end_pfn(region)) - 1;
251 insert_resource(&iomem_resource, res);
255 static int __init reserve_memblock_reserved_regions(void)
259 for (i = 0; i < num_standard_resources; ++i) {
260 struct resource *mem = &standard_resources[i];
261 phys_addr_t r_start, r_end, mem_size = resource_size(mem);
263 if (!memblock_is_region_reserved(mem->start, mem_size))
266 for_each_reserved_mem_range(j, &r_start, &r_end) {
267 resource_size_t start, end;
269 start = max(PFN_PHYS(PFN_DOWN(r_start)), mem->start);
270 end = min(PFN_PHYS(PFN_UP(r_end)) - 1, mem->end);
272 if (start > mem->end || end < mem->start)
275 reserve_region_with_split(mem, start, end, "reserved");
281 arch_initcall(reserve_memblock_reserved_regions);
283 u64 __cpu_logical_map[NR_CPUS] = { [0 ... NR_CPUS-1] = INVALID_HWID };
285 u64 cpu_logical_map(unsigned int cpu)
287 return __cpu_logical_map[cpu];
290 void __init __no_sanitize_address setup_arch(char **cmdline_p)
292 setup_initial_init_mm(_stext, _etext, _edata, _end);
294 *cmdline_p = boot_command_line;
297 * If know now we are going to need KPTI then use non-global
298 * mappings from the start, avoiding the cost of rewriting
301 arm64_use_ng_mappings = kaslr_requires_kpti();
304 early_ioremap_init();
306 setup_machine_fdt(__fdt_pointer);
309 * Initialise the static keys early as they may be enabled by the
310 * cpufeature code and early parameters.
316 * Unmask asynchronous aborts and fiq after bringing up possible
317 * earlycon. (Report possible System Errors once we can report this
320 local_daif_restore(DAIF_PROCCTX_NOIRQ);
323 * TTBR0 is only used for the identity mapping at this stage. Make it
324 * point to zero page to avoid speculatively fetching new entries.
326 cpu_uninstall_idmap();
331 if (!efi_enabled(EFI_BOOT) && ((u64)_text % MIN_KIMG_ALIGN) != 0)
332 pr_warn(FW_BUG "Kernel image misaligned at boot, please fix your bootloader!");
334 arm64_memblock_init();
338 acpi_table_upgrade();
340 /* Parse the ACPI tables for possible boot-time configuration */
341 acpi_boot_table_init();
344 unflatten_device_tree();
350 request_standard_resources();
352 early_ioremap_reset();
361 smp_build_mpidr_hash();
363 /* Init percpu seeds for random tags after cpus are set up. */
364 kasan_init_sw_tags();
366 #ifdef CONFIG_ARM64_SW_TTBR0_PAN
368 * Make sure init_thread_info.ttbr0 always generates translation
369 * faults in case uaccess_enable() is inadvertently called by the init
372 init_task.thread_info.ttbr0 = phys_to_ttbr(__pa_symbol(reserved_pg_dir));
375 if (boot_args[1] || boot_args[2] || boot_args[3]) {
376 pr_err("WARNING: x1-x3 nonzero in violation of boot protocol:\n"
377 "\tx1: %016llx\n\tx2: %016llx\n\tx3: %016llx\n"
378 "This indicates a broken bootloader or old kernel\n",
379 boot_args[1], boot_args[2], boot_args[3]);
383 static inline bool cpu_can_disable(unsigned int cpu)
385 #ifdef CONFIG_HOTPLUG_CPU
386 const struct cpu_operations *ops = get_cpu_ops(cpu);
388 if (ops && ops->cpu_can_disable)
389 return ops->cpu_can_disable(cpu);
394 static int __init topology_init(void)
398 for_each_possible_cpu(i) {
399 struct cpu *cpu = &per_cpu(cpu_data.cpu, i);
400 cpu->hotpluggable = cpu_can_disable(i);
401 register_cpu(cpu, i);
406 subsys_initcall(topology_init);
408 static void dump_kernel_offset(void)
410 const unsigned long offset = kaslr_offset();
412 if (IS_ENABLED(CONFIG_RANDOMIZE_BASE) && offset > 0) {
413 pr_emerg("Kernel Offset: 0x%lx from 0x%lx\n",
414 offset, KIMAGE_VADDR);
415 pr_emerg("PHYS_OFFSET: 0x%llx\n", PHYS_OFFSET);
417 pr_emerg("Kernel Offset: disabled\n");
421 static int arm64_panic_block_dump(struct notifier_block *self,
422 unsigned long v, void *p)
424 dump_kernel_offset();
430 static struct notifier_block arm64_panic_block = {
431 .notifier_call = arm64_panic_block_dump
434 static int __init register_arm64_panic_block(void)
436 atomic_notifier_chain_register(&panic_notifier_list,
440 device_initcall(register_arm64_panic_block);