2 * Based on arch/arm/kernel/setup.c
4 * Copyright (C) 1995-2001 Russell King
5 * Copyright (C) 2012 ARM Ltd.
7 * This program is free software; you can redistribute it and/or modify
8 * it under the terms of the GNU General Public License version 2 as
9 * published by the Free Software Foundation.
11 * This program is distributed in the hope that it will be useful,
12 * but WITHOUT ANY WARRANTY; without even the implied warranty of
13 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
14 * GNU General Public License for more details.
16 * You should have received a copy of the GNU General Public License
17 * along with this program. If not, see <http://www.gnu.org/licenses/>.
20 #include <linux/acpi.h>
21 #include <linux/export.h>
22 #include <linux/kernel.h>
23 #include <linux/stddef.h>
24 #include <linux/ioport.h>
25 #include <linux/delay.h>
26 #include <linux/initrd.h>
27 #include <linux/console.h>
28 #include <linux/cache.h>
29 #include <linux/screen_info.h>
30 #include <linux/init.h>
31 #include <linux/kexec.h>
32 #include <linux/root_dev.h>
33 #include <linux/cpu.h>
34 #include <linux/interrupt.h>
35 #include <linux/smp.h>
37 #include <linux/proc_fs.h>
38 #include <linux/memblock.h>
39 #include <linux/of_fdt.h>
40 #include <linux/efi.h>
41 #include <linux/psci.h>
42 #include <linux/sched/task.h>
46 #include <asm/fixmap.h>
48 #include <asm/cputype.h>
49 #include <asm/daifflags.h>
51 #include <asm/cpufeature.h>
52 #include <asm/cpu_ops.h>
53 #include <asm/kasan.h>
55 #include <asm/sections.h>
56 #include <asm/setup.h>
57 #include <asm/smp_plat.h>
58 #include <asm/cacheflush.h>
59 #include <asm/tlbflush.h>
60 #include <asm/traps.h>
62 #include <asm/xen/hypervisor.h>
63 #include <asm/mmu_context.h>
65 static int num_standard_resources;
66 static struct resource *standard_resources;
68 phys_addr_t __fdt_pointer __initdata;
71 * Standard memory resources
73 static struct resource mem_res[] = {
75 .name = "Kernel code",
78 .flags = IORESOURCE_SYSTEM_RAM
81 .name = "Kernel data",
84 .flags = IORESOURCE_SYSTEM_RAM
88 #define kernel_code mem_res[0]
89 #define kernel_data mem_res[1]
92 * The recorded values of x0 .. x3 upon kernel entry.
94 u64 __cacheline_aligned boot_args[4];
96 void __init smp_setup_processor_id(void)
98 u64 mpidr = read_cpuid_mpidr() & MPIDR_HWID_BITMASK;
99 cpu_logical_map(0) = mpidr;
102 * clear __my_cpu_offset on boot CPU to avoid hang caused by
103 * using percpu variable early, for example, lockdep will
104 * access percpu variable inside lock_release
106 set_my_cpu_offset(0);
107 pr_info("Booting Linux on physical CPU 0x%010lx [0x%08x]\n",
108 (unsigned long)mpidr, read_cpuid_id());
111 bool arch_match_cpu_phys_id(int cpu, u64 phys_id)
113 return phys_id == cpu_logical_map(cpu);
116 struct mpidr_hash mpidr_hash;
118 * smp_build_mpidr_hash - Pre-compute shifts required at each affinity
119 * level in order to build a linear index from an
120 * MPIDR value. Resulting algorithm is a collision
121 * free hash carried out through shifting and ORing
123 static void __init smp_build_mpidr_hash(void)
125 u32 i, affinity, fs[4], bits[4], ls;
128 * Pre-scan the list of MPIDRS and filter out bits that do
129 * not contribute to affinity levels, ie they never toggle.
131 for_each_possible_cpu(i)
132 mask |= (cpu_logical_map(i) ^ cpu_logical_map(0));
133 pr_debug("mask of set bits %#llx\n", mask);
135 * Find and stash the last and first bit set at all affinity levels to
136 * check how many bits are required to represent them.
138 for (i = 0; i < 4; i++) {
139 affinity = MPIDR_AFFINITY_LEVEL(mask, i);
141 * Find the MSB bit and LSB bits position
142 * to determine how many bits are required
143 * to express the affinity level.
146 fs[i] = affinity ? ffs(affinity) - 1 : 0;
147 bits[i] = ls - fs[i];
150 * An index can be created from the MPIDR_EL1 by isolating the
151 * significant bits at each affinity level and by shifting
152 * them in order to compress the 32 bits values space to a
153 * compressed set of values. This is equivalent to hashing
154 * the MPIDR_EL1 through shifting and ORing. It is a collision free
155 * hash though not minimal since some levels might contain a number
156 * of CPUs that is not an exact power of 2 and their bit
157 * representation might contain holes, eg MPIDR_EL1[7:0] = {0x2, 0x80}.
159 mpidr_hash.shift_aff[0] = MPIDR_LEVEL_SHIFT(0) + fs[0];
160 mpidr_hash.shift_aff[1] = MPIDR_LEVEL_SHIFT(1) + fs[1] - bits[0];
161 mpidr_hash.shift_aff[2] = MPIDR_LEVEL_SHIFT(2) + fs[2] -
163 mpidr_hash.shift_aff[3] = MPIDR_LEVEL_SHIFT(3) +
164 fs[3] - (bits[2] + bits[1] + bits[0]);
165 mpidr_hash.mask = mask;
166 mpidr_hash.bits = bits[3] + bits[2] + bits[1] + bits[0];
167 pr_debug("MPIDR hash: aff0[%u] aff1[%u] aff2[%u] aff3[%u] mask[%#llx] bits[%u]\n",
168 mpidr_hash.shift_aff[0],
169 mpidr_hash.shift_aff[1],
170 mpidr_hash.shift_aff[2],
171 mpidr_hash.shift_aff[3],
175 * 4x is an arbitrary value used to warn on a hash table much bigger
176 * than expected on most systems.
178 if (mpidr_hash_size() > 4 * num_possible_cpus())
179 pr_warn("Large number of MPIDR hash buckets detected\n");
182 static void __init setup_machine_fdt(phys_addr_t dt_phys)
184 void *dt_virt = fixmap_remap_fdt(dt_phys);
187 if (!dt_virt || !early_init_dt_scan(dt_virt)) {
189 "Error: invalid device tree blob at physical address %pa (virtual address 0x%p)\n"
190 "The dtb must be 8-byte aligned and must not exceed 2 MB in size\n"
191 "\nPlease check your bootloader.",
198 name = of_flat_dt_get_machine_name();
202 pr_info("Machine model: %s\n", name);
203 dump_stack_set_arch_desc("%s (DT)", name);
206 static void __init request_standard_resources(void)
208 struct memblock_region *region;
209 struct resource *res;
212 kernel_code.start = __pa_symbol(_text);
213 kernel_code.end = __pa_symbol(__init_begin - 1);
214 kernel_data.start = __pa_symbol(_sdata);
215 kernel_data.end = __pa_symbol(_end - 1);
217 num_standard_resources = memblock.memory.cnt;
218 standard_resources = memblock_alloc_low(num_standard_resources *
219 sizeof(*standard_resources),
222 for_each_memblock(memory, region) {
223 res = &standard_resources[i++];
224 if (memblock_is_nomap(region)) {
225 res->name = "reserved";
226 res->flags = IORESOURCE_MEM;
228 res->name = "System RAM";
229 res->flags = IORESOURCE_SYSTEM_RAM | IORESOURCE_BUSY;
231 res->start = __pfn_to_phys(memblock_region_memory_base_pfn(region));
232 res->end = __pfn_to_phys(memblock_region_memory_end_pfn(region)) - 1;
234 request_resource(&iomem_resource, res);
236 if (kernel_code.start >= res->start &&
237 kernel_code.end <= res->end)
238 request_resource(res, &kernel_code);
239 if (kernel_data.start >= res->start &&
240 kernel_data.end <= res->end)
241 request_resource(res, &kernel_data);
242 #ifdef CONFIG_KEXEC_CORE
243 /* Userspace will find "Crash kernel" region in /proc/iomem. */
244 if (crashk_res.end && crashk_res.start >= res->start &&
245 crashk_res.end <= res->end)
246 request_resource(res, &crashk_res);
251 static int __init reserve_memblock_reserved_regions(void)
255 for (i = 0; i < num_standard_resources; ++i) {
256 struct resource *mem = &standard_resources[i];
257 phys_addr_t r_start, r_end, mem_size = resource_size(mem);
259 if (!memblock_is_region_reserved(mem->start, mem_size))
262 for_each_reserved_mem_region(j, &r_start, &r_end) {
263 resource_size_t start, end;
265 start = max(PFN_PHYS(PFN_DOWN(r_start)), mem->start);
266 end = min(PFN_PHYS(PFN_UP(r_end)) - 1, mem->end);
268 if (start > mem->end || end < mem->start)
271 reserve_region_with_split(mem, start, end, "reserved");
277 arch_initcall(reserve_memblock_reserved_regions);
279 u64 __cpu_logical_map[NR_CPUS] = { [0 ... NR_CPUS-1] = INVALID_HWID };
281 void __init setup_arch(char **cmdline_p)
283 init_mm.start_code = (unsigned long) _text;
284 init_mm.end_code = (unsigned long) _etext;
285 init_mm.end_data = (unsigned long) _edata;
286 init_mm.brk = (unsigned long) _end;
288 *cmdline_p = boot_command_line;
291 early_ioremap_init();
293 setup_machine_fdt(__fdt_pointer);
298 * Unmask asynchronous aborts and fiq after bringing up possible
299 * earlycon. (Report possible System Errors once we can report this
302 local_daif_restore(DAIF_PROCCTX_NOIRQ);
305 * TTBR0 is only used for the identity mapping at this stage. Make it
306 * point to zero page to avoid speculatively fetching new entries.
308 cpu_uninstall_idmap();
312 arm64_memblock_init();
316 acpi_table_upgrade();
318 /* Parse the ACPI tables for possible boot-time configuration */
319 acpi_boot_table_init();
322 unflatten_device_tree();
328 request_standard_resources();
330 early_ioremap_reset();
337 cpu_read_bootcpu_ops();
339 smp_build_mpidr_hash();
341 /* Init percpu seeds for random tags after cpus are set up. */
344 #ifdef CONFIG_ARM64_SW_TTBR0_PAN
346 * Make sure init_thread_info.ttbr0 always generates translation
347 * faults in case uaccess_enable() is inadvertently called by the init
350 init_task.thread_info.ttbr0 = __pa_symbol(empty_zero_page);
354 conswitchp = &dummy_con;
356 if (boot_args[1] || boot_args[2] || boot_args[3]) {
357 pr_err("WARNING: x1-x3 nonzero in violation of boot protocol:\n"
358 "\tx1: %016llx\n\tx2: %016llx\n\tx3: %016llx\n"
359 "This indicates a broken bootloader or old kernel\n",
360 boot_args[1], boot_args[2], boot_args[3]);
364 static int __init topology_init(void)
368 for_each_online_node(i)
369 register_one_node(i);
371 for_each_possible_cpu(i) {
372 struct cpu *cpu = &per_cpu(cpu_data.cpu, i);
373 cpu->hotpluggable = 1;
374 register_cpu(cpu, i);
379 subsys_initcall(topology_init);
382 * Dump out kernel offset information on panic.
384 static int dump_kernel_offset(struct notifier_block *self, unsigned long v,
387 const unsigned long offset = kaslr_offset();
389 if (IS_ENABLED(CONFIG_RANDOMIZE_BASE) && offset > 0) {
390 pr_emerg("Kernel Offset: 0x%lx from 0x%lx\n",
391 offset, KIMAGE_VADDR);
392 pr_emerg("PHYS_OFFSET: 0x%llx\n", PHYS_OFFSET);
394 pr_emerg("Kernel Offset: disabled\n");
399 static struct notifier_block kernel_offset_notifier = {
400 .notifier_call = dump_kernel_offset
403 static int __init register_kernel_offset_dumper(void)
405 atomic_notifier_chain_register(&panic_notifier_list,
406 &kernel_offset_notifier);
409 __initcall(register_kernel_offset_dumper);