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/utsname.h>
27 #include <linux/initrd.h>
28 #include <linux/console.h>
29 #include <linux/cache.h>
30 #include <linux/bootmem.h>
31 #include <linux/screen_info.h>
32 #include <linux/init.h>
33 #include <linux/kexec.h>
34 #include <linux/crash_dump.h>
35 #include <linux/root_dev.h>
36 #include <linux/cpu.h>
37 #include <linux/interrupt.h>
38 #include <linux/smp.h>
40 #include <linux/proc_fs.h>
41 #include <linux/memblock.h>
42 #include <linux/of_iommu.h>
43 #include <linux/of_fdt.h>
44 #include <linux/of_platform.h>
45 #include <linux/efi.h>
46 #include <linux/psci.h>
49 #include <asm/fixmap.h>
51 #include <asm/cputype.h>
53 #include <asm/cpufeature.h>
54 #include <asm/cpu_ops.h>
55 #include <asm/kasan.h>
56 #include <asm/sections.h>
57 #include <asm/setup.h>
58 #include <asm/smp_plat.h>
59 #include <asm/cacheflush.h>
60 #include <asm/tlbflush.h>
61 #include <asm/traps.h>
62 #include <asm/memblock.h>
64 #include <asm/xen/hypervisor.h>
65 #include <asm/mmu_context.h>
67 phys_addr_t __fdt_pointer __initdata;
70 * Standard memory resources
72 static struct resource mem_res[] = {
74 .name = "Kernel code",
77 .flags = IORESOURCE_MEM
80 .name = "Kernel data",
83 .flags = IORESOURCE_MEM
87 #define kernel_code mem_res[0]
88 #define kernel_data mem_res[1]
91 * The recorded values of x0 .. x3 upon kernel entry.
93 u64 __cacheline_aligned boot_args[4];
95 void __init smp_setup_processor_id(void)
97 u64 mpidr = read_cpuid_mpidr() & MPIDR_HWID_BITMASK;
98 cpu_logical_map(0) = mpidr;
101 * clear __my_cpu_offset on boot CPU to avoid hang caused by
102 * using percpu variable early, for example, lockdep will
103 * access percpu variable inside lock_release
105 set_my_cpu_offset(0);
106 pr_info("Booting Linux on physical CPU 0x%lx\n", (unsigned long)mpidr);
109 bool arch_match_cpu_phys_id(int cpu, u64 phys_id)
111 return phys_id == cpu_logical_map(cpu);
114 struct mpidr_hash mpidr_hash;
116 * smp_build_mpidr_hash - Pre-compute shifts required at each affinity
117 * level in order to build a linear index from an
118 * MPIDR value. Resulting algorithm is a collision
119 * free hash carried out through shifting and ORing
121 static void __init smp_build_mpidr_hash(void)
123 u32 i, affinity, fs[4], bits[4], ls;
126 * Pre-scan the list of MPIDRS and filter out bits that do
127 * not contribute to affinity levels, ie they never toggle.
129 for_each_possible_cpu(i)
130 mask |= (cpu_logical_map(i) ^ cpu_logical_map(0));
131 pr_debug("mask of set bits %#llx\n", mask);
133 * Find and stash the last and first bit set at all affinity levels to
134 * check how many bits are required to represent them.
136 for (i = 0; i < 4; i++) {
137 affinity = MPIDR_AFFINITY_LEVEL(mask, i);
139 * Find the MSB bit and LSB bits position
140 * to determine how many bits are required
141 * to express the affinity level.
144 fs[i] = affinity ? ffs(affinity) - 1 : 0;
145 bits[i] = ls - fs[i];
148 * An index can be created from the MPIDR_EL1 by isolating the
149 * significant bits at each affinity level and by shifting
150 * them in order to compress the 32 bits values space to a
151 * compressed set of values. This is equivalent to hashing
152 * the MPIDR_EL1 through shifting and ORing. It is a collision free
153 * hash though not minimal since some levels might contain a number
154 * of CPUs that is not an exact power of 2 and their bit
155 * representation might contain holes, eg MPIDR_EL1[7:0] = {0x2, 0x80}.
157 mpidr_hash.shift_aff[0] = MPIDR_LEVEL_SHIFT(0) + fs[0];
158 mpidr_hash.shift_aff[1] = MPIDR_LEVEL_SHIFT(1) + fs[1] - bits[0];
159 mpidr_hash.shift_aff[2] = MPIDR_LEVEL_SHIFT(2) + fs[2] -
161 mpidr_hash.shift_aff[3] = MPIDR_LEVEL_SHIFT(3) +
162 fs[3] - (bits[2] + bits[1] + bits[0]);
163 mpidr_hash.mask = mask;
164 mpidr_hash.bits = bits[3] + bits[2] + bits[1] + bits[0];
165 pr_debug("MPIDR hash: aff0[%u] aff1[%u] aff2[%u] aff3[%u] mask[%#llx] bits[%u]\n",
166 mpidr_hash.shift_aff[0],
167 mpidr_hash.shift_aff[1],
168 mpidr_hash.shift_aff[2],
169 mpidr_hash.shift_aff[3],
173 * 4x is an arbitrary value used to warn on a hash table much bigger
174 * than expected on most systems.
176 if (mpidr_hash_size() > 4 * num_possible_cpus())
177 pr_warn("Large number of MPIDR hash buckets detected\n");
180 static void __init setup_machine_fdt(phys_addr_t dt_phys)
182 void *dt_virt = fixmap_remap_fdt(dt_phys);
184 if (!dt_virt || !early_init_dt_scan(dt_virt)) {
186 "Error: invalid device tree blob at physical address %pa (virtual address 0x%p)\n"
187 "The dtb must be 8-byte aligned and must not exceed 2 MB in size\n"
188 "\nPlease check your bootloader.",
195 dump_stack_set_arch_desc("%s (DT)", of_flat_dt_get_machine_name());
198 static void __init request_standard_resources(void)
200 struct memblock_region *region;
201 struct resource *res;
203 kernel_code.start = virt_to_phys(_text);
204 kernel_code.end = virt_to_phys(_etext - 1);
205 kernel_data.start = virt_to_phys(_sdata);
206 kernel_data.end = virt_to_phys(_end - 1);
208 for_each_memblock(memory, region) {
209 res = alloc_bootmem_low(sizeof(*res));
210 res->name = "System RAM";
211 res->start = __pfn_to_phys(memblock_region_memory_base_pfn(region));
212 res->end = __pfn_to_phys(memblock_region_memory_end_pfn(region)) - 1;
213 res->flags = IORESOURCE_MEM | IORESOURCE_BUSY;
215 request_resource(&iomem_resource, res);
217 if (kernel_code.start >= res->start &&
218 kernel_code.end <= res->end)
219 request_resource(res, &kernel_code);
220 if (kernel_data.start >= res->start &&
221 kernel_data.end <= res->end)
222 request_resource(res, &kernel_data);
226 #ifdef CONFIG_BLK_DEV_INITRD
228 * Relocate initrd if it is not completely within the linear mapping.
229 * This would be the case if mem= cuts out all or part of it.
231 static void __init relocate_initrd(void)
233 phys_addr_t orig_start = __virt_to_phys(initrd_start);
234 phys_addr_t orig_end = __virt_to_phys(initrd_end);
235 phys_addr_t ram_end = memblock_end_of_DRAM();
236 phys_addr_t new_start;
237 unsigned long size, to_free = 0;
240 if (orig_end <= ram_end)
244 * Any of the original initrd which overlaps the linear map should
245 * be freed after relocating.
247 if (orig_start < ram_end)
248 to_free = ram_end - orig_start;
250 size = orig_end - orig_start;
254 /* initrd needs to be relocated completely inside linear mapping */
255 new_start = memblock_find_in_range(0, PFN_PHYS(max_pfn),
258 panic("Cannot relocate initrd of size %ld\n", size);
259 memblock_reserve(new_start, size);
261 initrd_start = __phys_to_virt(new_start);
262 initrd_end = initrd_start + size;
264 pr_info("Moving initrd from [%llx-%llx] to [%llx-%llx]\n",
265 orig_start, orig_start + size - 1,
266 new_start, new_start + size - 1);
268 dest = (void *)initrd_start;
271 memcpy(dest, (void *)__phys_to_virt(orig_start), to_free);
275 copy_from_early_mem(dest, orig_start + to_free, size - to_free);
278 pr_info("Freeing original RAMDISK from [%llx-%llx]\n",
279 orig_start, orig_start + to_free - 1);
280 memblock_free(orig_start, to_free);
284 static inline void __init relocate_initrd(void)
289 u64 __cpu_logical_map[NR_CPUS] = { [0 ... NR_CPUS-1] = INVALID_HWID };
291 void __init setup_arch(char **cmdline_p)
293 pr_info("Boot CPU: AArch64 Processor [%08x]\n", read_cpuid_id());
295 sprintf(init_utsname()->machine, ELF_PLATFORM);
296 init_mm.start_code = (unsigned long) _text;
297 init_mm.end_code = (unsigned long) _etext;
298 init_mm.end_data = (unsigned long) _edata;
299 init_mm.brk = (unsigned long) _end;
301 *cmdline_p = boot_command_line;
304 early_ioremap_init();
306 setup_machine_fdt(__fdt_pointer);
311 * Unmask asynchronous aborts after bringing up possible earlycon.
312 * (Report possible System Errors once we can report this occurred)
314 local_async_enable();
317 * TTBR0 is only used for the identity mapping at this stage. Make it
318 * point to zero page to avoid speculatively fetching new entries.
320 cpu_uninstall_idmap();
323 arm64_memblock_init();
325 /* Parse the ACPI tables for possible boot-time configuration */
326 acpi_boot_table_init();
333 request_standard_resources();
335 early_ioremap_reset();
338 unflatten_device_tree();
345 cpu_read_bootcpu_ops();
347 smp_build_mpidr_hash();
350 #if defined(CONFIG_VGA_CONSOLE)
351 conswitchp = &vga_con;
352 #elif defined(CONFIG_DUMMY_CONSOLE)
353 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 arm64_device_init(void)
366 if (of_have_populated_dt()) {
368 of_platform_populate(NULL, of_default_bus_match_table,
370 } else if (acpi_disabled) {
371 pr_crit("Device tree not populated\n");
375 arch_initcall_sync(arm64_device_init);
377 static int __init topology_init(void)
381 for_each_possible_cpu(i) {
382 struct cpu *cpu = &per_cpu(cpu_data.cpu, i);
383 cpu->hotpluggable = 1;
384 register_cpu(cpu, i);
389 subsys_initcall(topology_init);