1 /*
2 * Based on arch/arm/kernel/setup.c
3 *
4 * Copyright (C) 1995-2001 Russell King
5 * Copyright (C) 2012 ARM Ltd.
6 *
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.
10 *
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.
15 *
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/>.
18 */
19
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>
39 #include <linux/fs.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>
47 #include <linux/mm.h>
48
49 #include <asm/acpi.h>
50 #include <asm/fixmap.h>
51 #include <asm/cpu.h>
52 #include <asm/cputype.h>
53 #include <asm/elf.h>
54 #include <asm/cpufeature.h>
55 #include <asm/cpu_ops.h>
56 #include <asm/kasan.h>
57 #include <asm/sections.h>
58 #include <asm/setup.h>
59 #include <asm/smp_plat.h>
60 #include <asm/cacheflush.h>
61 #include <asm/tlbflush.h>
62 #include <asm/traps.h>
63 #include <asm/memblock.h>
64 #include <asm/efi.h>
65 #include <asm/xen/hypervisor.h>
66 #include <asm/mmu_context.h>
67
68 phys_addr_t __fdt_pointer __initdata;
69
70 /*
71 * Standard memory resources
72 */
73 static struct resource mem_res[] = {
74 {
75 .name = "Kernel code",
76 .start = 0,
77 .end = 0,
78 .flags = IORESOURCE_MEM
79 },
80 {
81 .name = "Kernel data",
82 .start = 0,
83 .end = 0,
84 .flags = IORESOURCE_MEM
85 }
86 };
87
88 #define kernel_code mem_res[0]
89 #define kernel_data mem_res[1]
90
91 /*
92 * The recorded values of x0 .. x3 upon kernel entry.
93 */
94 u64 __cacheline_aligned boot_args[4];
95
smp_setup_processor_id(void)96 void __init smp_setup_processor_id(void)
97 {
98 u64 mpidr = read_cpuid_mpidr() & MPIDR_HWID_BITMASK;
99 cpu_logical_map(0) = mpidr;
100
101 /*
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
105 */
106 set_my_cpu_offset(0);
107 pr_info("Booting Linux on physical CPU 0x%lx\n", (unsigned long)mpidr);
108 }
109
arch_match_cpu_phys_id(int cpu,u64 phys_id)110 bool arch_match_cpu_phys_id(int cpu, u64 phys_id)
111 {
112 return phys_id == cpu_logical_map(cpu);
113 }
114
115 struct mpidr_hash mpidr_hash;
116 /**
117 * smp_build_mpidr_hash - Pre-compute shifts required at each affinity
118 * level in order to build a linear index from an
119 * MPIDR value. Resulting algorithm is a collision
120 * free hash carried out through shifting and ORing
121 */
smp_build_mpidr_hash(void)122 static void __init smp_build_mpidr_hash(void)
123 {
124 u32 i, affinity, fs[4], bits[4], ls;
125 u64 mask = 0;
126 /*
127 * Pre-scan the list of MPIDRS and filter out bits that do
128 * not contribute to affinity levels, ie they never toggle.
129 */
130 for_each_possible_cpu(i)
131 mask |= (cpu_logical_map(i) ^ cpu_logical_map(0));
132 pr_debug("mask of set bits %#llx\n", mask);
133 /*
134 * Find and stash the last and first bit set at all affinity levels to
135 * check how many bits are required to represent them.
136 */
137 for (i = 0; i < 4; i++) {
138 affinity = MPIDR_AFFINITY_LEVEL(mask, i);
139 /*
140 * Find the MSB bit and LSB bits position
141 * to determine how many bits are required
142 * to express the affinity level.
143 */
144 ls = fls(affinity);
145 fs[i] = affinity ? ffs(affinity) - 1 : 0;
146 bits[i] = ls - fs[i];
147 }
148 /*
149 * An index can be created from the MPIDR_EL1 by isolating the
150 * significant bits at each affinity level and by shifting
151 * them in order to compress the 32 bits values space to a
152 * compressed set of values. This is equivalent to hashing
153 * the MPIDR_EL1 through shifting and ORing. It is a collision free
154 * hash though not minimal since some levels might contain a number
155 * of CPUs that is not an exact power of 2 and their bit
156 * representation might contain holes, eg MPIDR_EL1[7:0] = {0x2, 0x80}.
157 */
158 mpidr_hash.shift_aff[0] = MPIDR_LEVEL_SHIFT(0) + fs[0];
159 mpidr_hash.shift_aff[1] = MPIDR_LEVEL_SHIFT(1) + fs[1] - bits[0];
160 mpidr_hash.shift_aff[2] = MPIDR_LEVEL_SHIFT(2) + fs[2] -
161 (bits[1] + bits[0]);
162 mpidr_hash.shift_aff[3] = MPIDR_LEVEL_SHIFT(3) +
163 fs[3] - (bits[2] + bits[1] + bits[0]);
164 mpidr_hash.mask = mask;
165 mpidr_hash.bits = bits[3] + bits[2] + bits[1] + bits[0];
166 pr_debug("MPIDR hash: aff0[%u] aff1[%u] aff2[%u] aff3[%u] mask[%#llx] bits[%u]\n",
167 mpidr_hash.shift_aff[0],
168 mpidr_hash.shift_aff[1],
169 mpidr_hash.shift_aff[2],
170 mpidr_hash.shift_aff[3],
171 mpidr_hash.mask,
172 mpidr_hash.bits);
173 /*
174 * 4x is an arbitrary value used to warn on a hash table much bigger
175 * than expected on most systems.
176 */
177 if (mpidr_hash_size() > 4 * num_possible_cpus())
178 pr_warn("Large number of MPIDR hash buckets detected\n");
179 __flush_dcache_area(&mpidr_hash, sizeof(struct mpidr_hash));
180 }
181
setup_machine_fdt(phys_addr_t dt_phys)182 static void __init setup_machine_fdt(phys_addr_t dt_phys)
183 {
184 void *dt_virt = fixmap_remap_fdt(dt_phys);
185
186 if (!dt_virt || !early_init_dt_scan(dt_virt)) {
187 pr_crit("\n"
188 "Error: invalid device tree blob at physical address %pa (virtual address 0x%p)\n"
189 "The dtb must be 8-byte aligned and must not exceed 2 MB in size\n"
190 "\nPlease check your bootloader.",
191 &dt_phys, dt_virt);
192
193 while (true)
194 cpu_relax();
195 }
196
197 dump_stack_set_arch_desc("%s (DT)", of_flat_dt_get_machine_name());
198 }
199
request_standard_resources(void)200 static void __init request_standard_resources(void)
201 {
202 struct memblock_region *region;
203 struct resource *res;
204
205 kernel_code.start = __pa_symbol(_text);
206 kernel_code.end = __pa_symbol(__init_begin - 1);
207 kernel_data.start = __pa_symbol(_sdata);
208 kernel_data.end = __pa_symbol(_end - 1);
209
210 for_each_memblock(memory, region) {
211 res = alloc_bootmem_low(sizeof(*res));
212 res->name = "System RAM";
213 res->start = __pfn_to_phys(memblock_region_memory_base_pfn(region));
214 res->end = __pfn_to_phys(memblock_region_memory_end_pfn(region)) - 1;
215 res->flags = IORESOURCE_MEM | IORESOURCE_BUSY;
216
217 request_resource(&iomem_resource, res);
218
219 if (kernel_code.start >= res->start &&
220 kernel_code.end <= res->end)
221 request_resource(res, &kernel_code);
222 if (kernel_data.start >= res->start &&
223 kernel_data.end <= res->end)
224 request_resource(res, &kernel_data);
225 }
226 }
227
228 #ifdef CONFIG_BLK_DEV_INITRD
229 /*
230 * Relocate initrd if it is not completely within the linear mapping.
231 * This would be the case if mem= cuts out all or part of it.
232 */
relocate_initrd(void)233 static void __init relocate_initrd(void)
234 {
235 phys_addr_t orig_start = __virt_to_phys(initrd_start);
236 phys_addr_t orig_end = __virt_to_phys(initrd_end);
237 phys_addr_t ram_end = memblock_end_of_DRAM();
238 phys_addr_t new_start;
239 unsigned long size, to_free = 0;
240 void *dest;
241
242 if (orig_end <= ram_end)
243 return;
244
245 /*
246 * Any of the original initrd which overlaps the linear map should
247 * be freed after relocating.
248 */
249 if (orig_start < ram_end)
250 to_free = ram_end - orig_start;
251
252 size = orig_end - orig_start;
253 if (!size)
254 return;
255
256 /* initrd needs to be relocated completely inside linear mapping */
257 new_start = memblock_find_in_range(0, PFN_PHYS(max_pfn),
258 size, PAGE_SIZE);
259 if (!new_start)
260 panic("Cannot relocate initrd of size %ld\n", size);
261 memblock_reserve(new_start, size);
262
263 initrd_start = __phys_to_virt(new_start);
264 initrd_end = initrd_start + size;
265
266 pr_info("Moving initrd from [%llx-%llx] to [%llx-%llx]\n",
267 orig_start, orig_start + size - 1,
268 new_start, new_start + size - 1);
269
270 dest = (void *)initrd_start;
271
272 if (to_free) {
273 memcpy(dest, (void *)__phys_to_virt(orig_start), to_free);
274 dest += to_free;
275 }
276
277 copy_from_early_mem(dest, orig_start + to_free, size - to_free);
278
279 if (to_free) {
280 pr_info("Freeing original RAMDISK from [%llx-%llx]\n",
281 orig_start, orig_start + to_free - 1);
282 memblock_free(orig_start, to_free);
283 }
284 }
285 #else
relocate_initrd(void)286 static inline void __init relocate_initrd(void)
287 {
288 }
289 #endif
290
291 u64 __cpu_logical_map[NR_CPUS] = { [0 ... NR_CPUS-1] = INVALID_HWID };
292
setup_arch(char ** cmdline_p)293 void __init setup_arch(char **cmdline_p)
294 {
295 pr_info("Boot CPU: AArch64 Processor [%08x]\n", read_cpuid_id());
296
297 sprintf(init_utsname()->machine, ELF_PLATFORM);
298 init_mm.start_code = (unsigned long) _text;
299 init_mm.end_code = (unsigned long) _etext;
300 init_mm.end_data = (unsigned long) _edata;
301 init_mm.brk = (unsigned long) _end;
302
303 *cmdline_p = boot_command_line;
304
305 early_fixmap_init();
306 early_ioremap_init();
307
308 setup_machine_fdt(__fdt_pointer);
309
310 parse_early_param();
311
312 /*
313 * Unmask asynchronous aborts after bringing up possible earlycon.
314 * (Report possible System Errors once we can report this occurred)
315 */
316 local_async_enable();
317
318 /*
319 * TTBR0 is only used for the identity mapping at this stage. Make it
320 * point to zero page to avoid speculatively fetching new entries.
321 */
322 cpu_uninstall_idmap();
323
324 efi_init();
325 arm64_memblock_init();
326
327 /* Parse the ACPI tables for possible boot-time configuration */
328 acpi_boot_table_init();
329
330 paging_init();
331 relocate_initrd();
332
333 kasan_init();
334
335 request_standard_resources();
336
337 early_ioremap_reset();
338
339 if (acpi_disabled) {
340 unflatten_device_tree();
341 psci_dt_init();
342 } else {
343 psci_acpi_init();
344 }
345 xen_early_init();
346
347 cpu_read_bootcpu_ops();
348 smp_init_cpus();
349 smp_build_mpidr_hash();
350
351 #ifdef CONFIG_ARM64_SW_TTBR0_PAN
352 /*
353 * Make sure thread_info.ttbr0 always generates translation
354 * faults in case uaccess_enable() is inadvertently called by the init
355 * thread.
356 */
357 #ifdef CONFIG_THREAD_INFO_IN_TASK
358 init_task.thread_info.ttbr0 = __pa_symbol(empty_zero_page);
359 #else
360 init_thread_info.ttbr0 = __pa_symbol(empty_zero_page);
361 #endif
362 #endif
363
364 #ifdef CONFIG_VT
365 #if defined(CONFIG_VGA_CONSOLE)
366 conswitchp = &vga_con;
367 #elif defined(CONFIG_DUMMY_CONSOLE)
368 conswitchp = &dummy_con;
369 #endif
370 #endif
371 if (boot_args[1] || boot_args[2] || boot_args[3]) {
372 pr_err("WARNING: x1-x3 nonzero in violation of boot protocol:\n"
373 "\tx1: %016llx\n\tx2: %016llx\n\tx3: %016llx\n"
374 "This indicates a broken bootloader or old kernel\n",
375 boot_args[1], boot_args[2], boot_args[3]);
376 }
377 }
378
arm64_device_init(void)379 static int __init arm64_device_init(void)
380 {
381 if (of_have_populated_dt()) {
382 of_iommu_init();
383 of_platform_populate(NULL, of_default_bus_match_table,
384 NULL, NULL);
385 } else if (acpi_disabled) {
386 pr_crit("Device tree not populated\n");
387 }
388 return 0;
389 }
390 arch_initcall_sync(arm64_device_init);
391
topology_init(void)392 static int __init topology_init(void)
393 {
394 int i;
395
396 for_each_possible_cpu(i) {
397 struct cpu *cpu = &per_cpu(cpu_data.cpu, i);
398 cpu->hotpluggable = 1;
399 register_cpu(cpu, i);
400 }
401
402 return 0;
403 }
404 subsys_initcall(topology_init);
405
406 /*
407 * Dump out kernel offset information on panic.
408 */
dump_kernel_offset(struct notifier_block * self,unsigned long v,void * p)409 static int dump_kernel_offset(struct notifier_block *self, unsigned long v,
410 void *p)
411 {
412 const unsigned long offset = kaslr_offset();
413
414 if (IS_ENABLED(CONFIG_RANDOMIZE_BASE) && offset > 0) {
415 pr_emerg("Kernel Offset: 0x%lx from 0x%lx\n",
416 offset, KIMAGE_VADDR);
417 } else {
418 pr_emerg("Kernel Offset: disabled\n");
419 }
420 return 0;
421 }
422
423 static struct notifier_block kernel_offset_notifier = {
424 .notifier_call = dump_kernel_offset
425 };
426
register_kernel_offset_dumper(void)427 static int __init register_kernel_offset_dumper(void)
428 {
429 atomic_notifier_chain_register(&panic_notifier_list,
430 &kernel_offset_notifier);
431 return 0;
432 }
433 __initcall(register_kernel_offset_dumper);
434