xref: /linux/arch/arm/kernel/setup.c (revision 0da908c291070d89482f6211dbe81d4d43c3f7cb)
1 // SPDX-License-Identifier: GPL-2.0-only
2 /*
3  *  linux/arch/arm/kernel/setup.c
4  *
5  *  Copyright (C) 1995-2001 Russell King
6  */
7 #include <linux/efi.h>
8 #include <linux/export.h>
9 #include <linux/kernel.h>
10 #include <linux/stddef.h>
11 #include <linux/ioport.h>
12 #include <linux/delay.h>
13 #include <linux/utsname.h>
14 #include <linux/initrd.h>
15 #include <linux/console.h>
16 #include <linux/seq_file.h>
17 #include <linux/screen_info.h>
18 #include <linux/of_platform.h>
19 #include <linux/init.h>
20 #include <linux/kexec.h>
21 #include <linux/libfdt.h>
22 #include <linux/of_fdt.h>
23 #include <linux/cpu.h>
24 #include <linux/interrupt.h>
25 #include <linux/smp.h>
26 #include <linux/proc_fs.h>
27 #include <linux/memblock.h>
28 #include <linux/bug.h>
29 #include <linux/compiler.h>
30 #include <linux/sort.h>
31 #include <linux/psci.h>
32 
33 #include <asm/unified.h>
34 #include <asm/cp15.h>
35 #include <asm/cpu.h>
36 #include <asm/cputype.h>
37 #include <asm/efi.h>
38 #include <asm/elf.h>
39 #include <asm/early_ioremap.h>
40 #include <asm/fixmap.h>
41 #include <asm/procinfo.h>
42 #include <asm/psci.h>
43 #include <asm/sections.h>
44 #include <asm/setup.h>
45 #include <asm/smp_plat.h>
46 #include <asm/mach-types.h>
47 #include <asm/cacheflush.h>
48 #include <asm/cachetype.h>
49 #include <asm/tlbflush.h>
50 #include <asm/xen/hypervisor.h>
51 
52 #include <asm/prom.h>
53 #include <asm/mach/arch.h>
54 #include <asm/mach/irq.h>
55 #include <asm/mach/time.h>
56 #include <asm/system_info.h>
57 #include <asm/system_misc.h>
58 #include <asm/traps.h>
59 #include <asm/unwind.h>
60 #include <asm/memblock.h>
61 #include <asm/virt.h>
62 #include <asm/kasan.h>
63 
64 #include "atags.h"
65 
66 
67 #if defined(CONFIG_FPE_NWFPE) || defined(CONFIG_FPE_FASTFPE)
68 char fpe_type[8];
69 
70 static int __init fpe_setup(char *line)
71 {
72 	memcpy(fpe_type, line, 8);
73 	return 1;
74 }
75 
76 __setup("fpe=", fpe_setup);
77 #endif
78 
79 extern void init_default_cache_policy(unsigned long);
80 extern void paging_init(const struct machine_desc *desc);
81 extern void early_mm_init(const struct machine_desc *);
82 extern void adjust_lowmem_bounds(void);
83 extern enum reboot_mode reboot_mode;
84 extern void setup_dma_zone(const struct machine_desc *desc);
85 
86 unsigned int processor_id;
87 EXPORT_SYMBOL(processor_id);
88 unsigned int __machine_arch_type __read_mostly;
89 EXPORT_SYMBOL(__machine_arch_type);
90 unsigned int cacheid __read_mostly;
91 EXPORT_SYMBOL(cacheid);
92 
93 unsigned int __atags_pointer __initdata;
94 
95 unsigned int system_rev;
96 EXPORT_SYMBOL(system_rev);
97 
98 const char *system_serial;
99 EXPORT_SYMBOL(system_serial);
100 
101 unsigned int system_serial_low;
102 EXPORT_SYMBOL(system_serial_low);
103 
104 unsigned int system_serial_high;
105 EXPORT_SYMBOL(system_serial_high);
106 
107 unsigned int elf_hwcap __read_mostly;
108 EXPORT_SYMBOL(elf_hwcap);
109 
110 unsigned int elf_hwcap2 __read_mostly;
111 EXPORT_SYMBOL(elf_hwcap2);
112 
113 
114 #ifdef MULTI_CPU
115 struct processor processor __ro_after_init;
116 #if defined(CONFIG_BIG_LITTLE) && defined(CONFIG_HARDEN_BRANCH_PREDICTOR)
117 struct processor *cpu_vtable[NR_CPUS] = {
118 	[0] = &processor,
119 };
120 #endif
121 #endif
122 #ifdef MULTI_TLB
123 struct cpu_tlb_fns cpu_tlb __ro_after_init;
124 #endif
125 #ifdef MULTI_USER
126 struct cpu_user_fns cpu_user __ro_after_init;
127 #endif
128 #ifdef MULTI_CACHE
129 struct cpu_cache_fns cpu_cache __ro_after_init;
130 #endif
131 #ifdef CONFIG_OUTER_CACHE
132 struct outer_cache_fns outer_cache __ro_after_init;
133 EXPORT_SYMBOL(outer_cache);
134 #endif
135 
136 /*
137  * Cached cpu_architecture() result for use by assembler code.
138  * C code should use the cpu_architecture() function instead of accessing this
139  * variable directly.
140  */
141 int __cpu_architecture __read_mostly = CPU_ARCH_UNKNOWN;
142 
143 struct stack {
144 	u32 irq[4];
145 	u32 abt[4];
146 	u32 und[4];
147 	u32 fiq[4];
148 } ____cacheline_aligned;
149 
150 #ifndef CONFIG_CPU_V7M
151 static struct stack stacks[NR_CPUS];
152 #endif
153 
154 char elf_platform[ELF_PLATFORM_SIZE];
155 EXPORT_SYMBOL(elf_platform);
156 
157 static const char *cpu_name;
158 static const char *machine_name;
159 static char __initdata cmd_line[COMMAND_LINE_SIZE];
160 const struct machine_desc *machine_desc __initdata;
161 
162 static union { char c[4]; unsigned long l; } endian_test __initdata = { { 'l', '?', '?', 'b' } };
163 #define ENDIANNESS ((char)endian_test.l)
164 
165 DEFINE_PER_CPU(struct cpuinfo_arm, cpu_data);
166 
167 /*
168  * Standard memory resources
169  */
170 static struct resource mem_res[] = {
171 	{
172 		.name = "Video RAM",
173 		.start = 0,
174 		.end = 0,
175 		.flags = IORESOURCE_MEM
176 	},
177 	{
178 		.name = "Kernel code",
179 		.start = 0,
180 		.end = 0,
181 		.flags = IORESOURCE_SYSTEM_RAM
182 	},
183 	{
184 		.name = "Kernel data",
185 		.start = 0,
186 		.end = 0,
187 		.flags = IORESOURCE_SYSTEM_RAM
188 	}
189 };
190 
191 #define video_ram   mem_res[0]
192 #define kernel_code mem_res[1]
193 #define kernel_data mem_res[2]
194 
195 static struct resource io_res[] = {
196 	{
197 		.name = "reserved",
198 		.start = 0x3bc,
199 		.end = 0x3be,
200 		.flags = IORESOURCE_IO | IORESOURCE_BUSY
201 	},
202 	{
203 		.name = "reserved",
204 		.start = 0x378,
205 		.end = 0x37f,
206 		.flags = IORESOURCE_IO | IORESOURCE_BUSY
207 	},
208 	{
209 		.name = "reserved",
210 		.start = 0x278,
211 		.end = 0x27f,
212 		.flags = IORESOURCE_IO | IORESOURCE_BUSY
213 	}
214 };
215 
216 #define lp0 io_res[0]
217 #define lp1 io_res[1]
218 #define lp2 io_res[2]
219 
220 static const char *proc_arch[] = {
221 	"undefined/unknown",
222 	"3",
223 	"4",
224 	"4T",
225 	"5",
226 	"5T",
227 	"5TE",
228 	"5TEJ",
229 	"6TEJ",
230 	"7",
231 	"7M",
232 	"?(12)",
233 	"?(13)",
234 	"?(14)",
235 	"?(15)",
236 	"?(16)",
237 	"?(17)",
238 };
239 
240 #ifdef CONFIG_CPU_V7M
241 static int __get_cpu_architecture(void)
242 {
243 	return CPU_ARCH_ARMv7M;
244 }
245 #else
246 static int __get_cpu_architecture(void)
247 {
248 	int cpu_arch;
249 
250 	if ((read_cpuid_id() & 0x0008f000) == 0) {
251 		cpu_arch = CPU_ARCH_UNKNOWN;
252 	} else if ((read_cpuid_id() & 0x0008f000) == 0x00007000) {
253 		cpu_arch = (read_cpuid_id() & (1 << 23)) ? CPU_ARCH_ARMv4T : CPU_ARCH_ARMv3;
254 	} else if ((read_cpuid_id() & 0x00080000) == 0x00000000) {
255 		cpu_arch = (read_cpuid_id() >> 16) & 7;
256 		if (cpu_arch)
257 			cpu_arch += CPU_ARCH_ARMv3;
258 	} else if ((read_cpuid_id() & 0x000f0000) == 0x000f0000) {
259 		/* Revised CPUID format. Read the Memory Model Feature
260 		 * Register 0 and check for VMSAv7 or PMSAv7 */
261 		unsigned int mmfr0 = read_cpuid_ext(CPUID_EXT_MMFR0);
262 		if ((mmfr0 & 0x0000000f) >= 0x00000003 ||
263 		    (mmfr0 & 0x000000f0) >= 0x00000030)
264 			cpu_arch = CPU_ARCH_ARMv7;
265 		else if ((mmfr0 & 0x0000000f) == 0x00000002 ||
266 			 (mmfr0 & 0x000000f0) == 0x00000020)
267 			cpu_arch = CPU_ARCH_ARMv6;
268 		else
269 			cpu_arch = CPU_ARCH_UNKNOWN;
270 	} else
271 		cpu_arch = CPU_ARCH_UNKNOWN;
272 
273 	return cpu_arch;
274 }
275 #endif
276 
277 int __pure cpu_architecture(void)
278 {
279 	BUG_ON(__cpu_architecture == CPU_ARCH_UNKNOWN);
280 
281 	return __cpu_architecture;
282 }
283 
284 static int cpu_has_aliasing_icache(unsigned int arch)
285 {
286 	int aliasing_icache;
287 	unsigned int id_reg, num_sets, line_size;
288 
289 	/* PIPT caches never alias. */
290 	if (icache_is_pipt())
291 		return 0;
292 
293 	/* arch specifies the register format */
294 	switch (arch) {
295 	case CPU_ARCH_ARMv7:
296 		set_csselr(CSSELR_ICACHE | CSSELR_L1);
297 		isb();
298 		id_reg = read_ccsidr();
299 		line_size = 4 << ((id_reg & 0x7) + 2);
300 		num_sets = ((id_reg >> 13) & 0x7fff) + 1;
301 		aliasing_icache = (line_size * num_sets) > PAGE_SIZE;
302 		break;
303 	case CPU_ARCH_ARMv6:
304 		aliasing_icache = read_cpuid_cachetype() & (1 << 11);
305 		break;
306 	default:
307 		/* I-cache aliases will be handled by D-cache aliasing code */
308 		aliasing_icache = 0;
309 	}
310 
311 	return aliasing_icache;
312 }
313 
314 static void __init cacheid_init(void)
315 {
316 	unsigned int arch = cpu_architecture();
317 
318 	if (arch >= CPU_ARCH_ARMv6) {
319 		unsigned int cachetype = read_cpuid_cachetype();
320 
321 		if ((arch == CPU_ARCH_ARMv7M) && !(cachetype & 0xf000f)) {
322 			cacheid = 0;
323 		} else if ((cachetype & (7 << 29)) == 4 << 29) {
324 			/* ARMv7 register format */
325 			arch = CPU_ARCH_ARMv7;
326 			cacheid = CACHEID_VIPT_NONALIASING;
327 			switch (cachetype & (3 << 14)) {
328 			case (1 << 14):
329 				cacheid |= CACHEID_ASID_TAGGED;
330 				break;
331 			case (3 << 14):
332 				cacheid |= CACHEID_PIPT;
333 				break;
334 			}
335 		} else {
336 			arch = CPU_ARCH_ARMv6;
337 			if (cachetype & (1 << 23))
338 				cacheid = CACHEID_VIPT_ALIASING;
339 			else
340 				cacheid = CACHEID_VIPT_NONALIASING;
341 		}
342 		if (cpu_has_aliasing_icache(arch))
343 			cacheid |= CACHEID_VIPT_I_ALIASING;
344 	} else {
345 		cacheid = CACHEID_VIVT;
346 	}
347 
348 	pr_info("CPU: %s data cache, %s instruction cache\n",
349 		cache_is_vivt() ? "VIVT" :
350 		cache_is_vipt_aliasing() ? "VIPT aliasing" :
351 		cache_is_vipt_nonaliasing() ? "PIPT / VIPT nonaliasing" : "unknown",
352 		cache_is_vivt() ? "VIVT" :
353 		icache_is_vivt_asid_tagged() ? "VIVT ASID tagged" :
354 		icache_is_vipt_aliasing() ? "VIPT aliasing" :
355 		icache_is_pipt() ? "PIPT" :
356 		cache_is_vipt_nonaliasing() ? "VIPT nonaliasing" : "unknown");
357 }
358 
359 /*
360  * These functions re-use the assembly code in head.S, which
361  * already provide the required functionality.
362  */
363 extern struct proc_info_list *lookup_processor_type(unsigned int);
364 
365 void __init early_print(const char *str, ...)
366 {
367 	extern void printascii(const char *);
368 	char buf[256];
369 	va_list ap;
370 
371 	va_start(ap, str);
372 	vsnprintf(buf, sizeof(buf), str, ap);
373 	va_end(ap);
374 
375 #ifdef CONFIG_DEBUG_LL
376 	printascii(buf);
377 #endif
378 	printk("%s", buf);
379 }
380 
381 #ifdef CONFIG_ARM_PATCH_IDIV
382 
383 static inline u32 __attribute_const__ sdiv_instruction(void)
384 {
385 	if (IS_ENABLED(CONFIG_THUMB2_KERNEL)) {
386 		/* "sdiv r0, r0, r1" */
387 		u32 insn = __opcode_thumb32_compose(0xfb90, 0xf0f1);
388 		return __opcode_to_mem_thumb32(insn);
389 	}
390 
391 	/* "sdiv r0, r0, r1" */
392 	return __opcode_to_mem_arm(0xe710f110);
393 }
394 
395 static inline u32 __attribute_const__ udiv_instruction(void)
396 {
397 	if (IS_ENABLED(CONFIG_THUMB2_KERNEL)) {
398 		/* "udiv r0, r0, r1" */
399 		u32 insn = __opcode_thumb32_compose(0xfbb0, 0xf0f1);
400 		return __opcode_to_mem_thumb32(insn);
401 	}
402 
403 	/* "udiv r0, r0, r1" */
404 	return __opcode_to_mem_arm(0xe730f110);
405 }
406 
407 static inline u32 __attribute_const__ bx_lr_instruction(void)
408 {
409 	if (IS_ENABLED(CONFIG_THUMB2_KERNEL)) {
410 		/* "bx lr; nop" */
411 		u32 insn = __opcode_thumb32_compose(0x4770, 0x46c0);
412 		return __opcode_to_mem_thumb32(insn);
413 	}
414 
415 	/* "bx lr" */
416 	return __opcode_to_mem_arm(0xe12fff1e);
417 }
418 
419 static void __init patch_aeabi_idiv(void)
420 {
421 	extern void __aeabi_uidiv(void);
422 	extern void __aeabi_idiv(void);
423 	uintptr_t fn_addr;
424 	unsigned int mask;
425 
426 	mask = IS_ENABLED(CONFIG_THUMB2_KERNEL) ? HWCAP_IDIVT : HWCAP_IDIVA;
427 	if (!(elf_hwcap & mask))
428 		return;
429 
430 	pr_info("CPU: div instructions available: patching division code\n");
431 
432 	fn_addr = ((uintptr_t)&__aeabi_uidiv) & ~1;
433 	asm ("" : "+g" (fn_addr));
434 	((u32 *)fn_addr)[0] = udiv_instruction();
435 	((u32 *)fn_addr)[1] = bx_lr_instruction();
436 	flush_icache_range(fn_addr, fn_addr + 8);
437 
438 	fn_addr = ((uintptr_t)&__aeabi_idiv) & ~1;
439 	asm ("" : "+g" (fn_addr));
440 	((u32 *)fn_addr)[0] = sdiv_instruction();
441 	((u32 *)fn_addr)[1] = bx_lr_instruction();
442 	flush_icache_range(fn_addr, fn_addr + 8);
443 }
444 
445 #else
446 static inline void patch_aeabi_idiv(void) { }
447 #endif
448 
449 static void __init cpuid_init_hwcaps(void)
450 {
451 	int block;
452 	u32 isar5;
453 	u32 isar6;
454 	u32 pfr2;
455 
456 	if (cpu_architecture() < CPU_ARCH_ARMv7)
457 		return;
458 
459 	block = cpuid_feature_extract(CPUID_EXT_ISAR0, 24);
460 	if (block >= 2)
461 		elf_hwcap |= HWCAP_IDIVA;
462 	if (block >= 1)
463 		elf_hwcap |= HWCAP_IDIVT;
464 
465 	/* LPAE implies atomic ldrd/strd instructions */
466 	block = cpuid_feature_extract(CPUID_EXT_MMFR0, 0);
467 	if (block >= 5)
468 		elf_hwcap |= HWCAP_LPAE;
469 
470 	/* check for supported v8 Crypto instructions */
471 	isar5 = read_cpuid_ext(CPUID_EXT_ISAR5);
472 
473 	block = cpuid_feature_extract_field(isar5, 4);
474 	if (block >= 2)
475 		elf_hwcap2 |= HWCAP2_PMULL;
476 	if (block >= 1)
477 		elf_hwcap2 |= HWCAP2_AES;
478 
479 	block = cpuid_feature_extract_field(isar5, 8);
480 	if (block >= 1)
481 		elf_hwcap2 |= HWCAP2_SHA1;
482 
483 	block = cpuid_feature_extract_field(isar5, 12);
484 	if (block >= 1)
485 		elf_hwcap2 |= HWCAP2_SHA2;
486 
487 	block = cpuid_feature_extract_field(isar5, 16);
488 	if (block >= 1)
489 		elf_hwcap2 |= HWCAP2_CRC32;
490 
491 	/* Check for Speculation barrier instruction */
492 	isar6 = read_cpuid_ext(CPUID_EXT_ISAR6);
493 	block = cpuid_feature_extract_field(isar6, 12);
494 	if (block >= 1)
495 		elf_hwcap2 |= HWCAP2_SB;
496 
497 	/* Check for Speculative Store Bypassing control */
498 	pfr2 = read_cpuid_ext(CPUID_EXT_PFR2);
499 	block = cpuid_feature_extract_field(pfr2, 4);
500 	if (block >= 1)
501 		elf_hwcap2 |= HWCAP2_SSBS;
502 }
503 
504 static void __init elf_hwcap_fixup(void)
505 {
506 	unsigned id = read_cpuid_id();
507 
508 	/*
509 	 * HWCAP_TLS is available only on 1136 r1p0 and later,
510 	 * see also kuser_get_tls_init.
511 	 */
512 	if (read_cpuid_part() == ARM_CPU_PART_ARM1136 &&
513 	    ((id >> 20) & 3) == 0) {
514 		elf_hwcap &= ~HWCAP_TLS;
515 		return;
516 	}
517 
518 	/* Verify if CPUID scheme is implemented */
519 	if ((id & 0x000f0000) != 0x000f0000)
520 		return;
521 
522 	/*
523 	 * If the CPU supports LDREX/STREX and LDREXB/STREXB,
524 	 * avoid advertising SWP; it may not be atomic with
525 	 * multiprocessing cores.
526 	 */
527 	if (cpuid_feature_extract(CPUID_EXT_ISAR3, 12) > 1 ||
528 	    (cpuid_feature_extract(CPUID_EXT_ISAR3, 12) == 1 &&
529 	     cpuid_feature_extract(CPUID_EXT_ISAR4, 20) >= 3))
530 		elf_hwcap &= ~HWCAP_SWP;
531 }
532 
533 /*
534  * cpu_init - initialise one CPU.
535  *
536  * cpu_init sets up the per-CPU stacks.
537  */
538 void notrace cpu_init(void)
539 {
540 #ifndef CONFIG_CPU_V7M
541 	unsigned int cpu = smp_processor_id();
542 	struct stack *stk = &stacks[cpu];
543 
544 	if (cpu >= NR_CPUS) {
545 		pr_crit("CPU%u: bad primary CPU number\n", cpu);
546 		BUG();
547 	}
548 
549 	/*
550 	 * This only works on resume and secondary cores. For booting on the
551 	 * boot cpu, smp_prepare_boot_cpu is called after percpu area setup.
552 	 */
553 	set_my_cpu_offset(per_cpu_offset(cpu));
554 
555 	cpu_proc_init();
556 
557 	/*
558 	 * Define the placement constraint for the inline asm directive below.
559 	 * In Thumb-2, msr with an immediate value is not allowed.
560 	 */
561 #ifdef CONFIG_THUMB2_KERNEL
562 #define PLC_l	"l"
563 #define PLC_r	"r"
564 #else
565 #define PLC_l	"I"
566 #define PLC_r	"I"
567 #endif
568 
569 	/*
570 	 * setup stacks for re-entrant exception handlers
571 	 */
572 	__asm__ (
573 	"msr	cpsr_c, %1\n\t"
574 	"add	r14, %0, %2\n\t"
575 	"mov	sp, r14\n\t"
576 	"msr	cpsr_c, %3\n\t"
577 	"add	r14, %0, %4\n\t"
578 	"mov	sp, r14\n\t"
579 	"msr	cpsr_c, %5\n\t"
580 	"add	r14, %0, %6\n\t"
581 	"mov	sp, r14\n\t"
582 	"msr	cpsr_c, %7\n\t"
583 	"add	r14, %0, %8\n\t"
584 	"mov	sp, r14\n\t"
585 	"msr	cpsr_c, %9"
586 	    :
587 	    : "r" (stk),
588 	      PLC_r (PSR_F_BIT | PSR_I_BIT | IRQ_MODE),
589 	      "I" (offsetof(struct stack, irq[0])),
590 	      PLC_r (PSR_F_BIT | PSR_I_BIT | ABT_MODE),
591 	      "I" (offsetof(struct stack, abt[0])),
592 	      PLC_r (PSR_F_BIT | PSR_I_BIT | UND_MODE),
593 	      "I" (offsetof(struct stack, und[0])),
594 	      PLC_r (PSR_F_BIT | PSR_I_BIT | FIQ_MODE),
595 	      "I" (offsetof(struct stack, fiq[0])),
596 	      PLC_l (PSR_F_BIT | PSR_I_BIT | SVC_MODE)
597 	    : "r14");
598 #endif
599 }
600 
601 u32 __cpu_logical_map[NR_CPUS] = { [0 ... NR_CPUS-1] = MPIDR_INVALID };
602 
603 void __init smp_setup_processor_id(void)
604 {
605 	int i;
606 	u32 mpidr = is_smp() ? read_cpuid_mpidr() & MPIDR_HWID_BITMASK : 0;
607 	u32 cpu = MPIDR_AFFINITY_LEVEL(mpidr, 0);
608 
609 	cpu_logical_map(0) = cpu;
610 	for (i = 1; i < nr_cpu_ids; ++i)
611 		cpu_logical_map(i) = i == cpu ? 0 : i;
612 
613 	/*
614 	 * clear __my_cpu_offset on boot CPU to avoid hang caused by
615 	 * using percpu variable early, for example, lockdep will
616 	 * access percpu variable inside lock_release
617 	 */
618 	set_my_cpu_offset(0);
619 
620 	pr_info("Booting Linux on physical CPU 0x%x\n", mpidr);
621 }
622 
623 struct mpidr_hash mpidr_hash;
624 #ifdef CONFIG_SMP
625 /**
626  * smp_build_mpidr_hash - Pre-compute shifts required at each affinity
627  *			  level in order to build a linear index from an
628  *			  MPIDR value. Resulting algorithm is a collision
629  *			  free hash carried out through shifting and ORing
630  */
631 static void __init smp_build_mpidr_hash(void)
632 {
633 	u32 i, affinity;
634 	u32 fs[3], bits[3], ls, mask = 0;
635 	/*
636 	 * Pre-scan the list of MPIDRS and filter out bits that do
637 	 * not contribute to affinity levels, ie they never toggle.
638 	 */
639 	for_each_possible_cpu(i)
640 		mask |= (cpu_logical_map(i) ^ cpu_logical_map(0));
641 	pr_debug("mask of set bits 0x%x\n", mask);
642 	/*
643 	 * Find and stash the last and first bit set at all affinity levels to
644 	 * check how many bits are required to represent them.
645 	 */
646 	for (i = 0; i < 3; i++) {
647 		affinity = MPIDR_AFFINITY_LEVEL(mask, i);
648 		/*
649 		 * Find the MSB bit and LSB bits position
650 		 * to determine how many bits are required
651 		 * to express the affinity level.
652 		 */
653 		ls = fls(affinity);
654 		fs[i] = affinity ? ffs(affinity) - 1 : 0;
655 		bits[i] = ls - fs[i];
656 	}
657 	/*
658 	 * An index can be created from the MPIDR by isolating the
659 	 * significant bits at each affinity level and by shifting
660 	 * them in order to compress the 24 bits values space to a
661 	 * compressed set of values. This is equivalent to hashing
662 	 * the MPIDR through shifting and ORing. It is a collision free
663 	 * hash though not minimal since some levels might contain a number
664 	 * of CPUs that is not an exact power of 2 and their bit
665 	 * representation might contain holes, eg MPIDR[7:0] = {0x2, 0x80}.
666 	 */
667 	mpidr_hash.shift_aff[0] = fs[0];
668 	mpidr_hash.shift_aff[1] = MPIDR_LEVEL_BITS + fs[1] - bits[0];
669 	mpidr_hash.shift_aff[2] = 2*MPIDR_LEVEL_BITS + fs[2] -
670 						(bits[1] + bits[0]);
671 	mpidr_hash.mask = mask;
672 	mpidr_hash.bits = bits[2] + bits[1] + bits[0];
673 	pr_debug("MPIDR hash: aff0[%u] aff1[%u] aff2[%u] mask[0x%x] bits[%u]\n",
674 				mpidr_hash.shift_aff[0],
675 				mpidr_hash.shift_aff[1],
676 				mpidr_hash.shift_aff[2],
677 				mpidr_hash.mask,
678 				mpidr_hash.bits);
679 	/*
680 	 * 4x is an arbitrary value used to warn on a hash table much bigger
681 	 * than expected on most systems.
682 	 */
683 	if (mpidr_hash_size() > 4 * num_possible_cpus())
684 		pr_warn("Large number of MPIDR hash buckets detected\n");
685 	sync_cache_w(&mpidr_hash);
686 }
687 #endif
688 
689 /*
690  * locate processor in the list of supported processor types.  The linker
691  * builds this table for us from the entries in arch/arm/mm/proc-*.S
692  */
693 struct proc_info_list *lookup_processor(u32 midr)
694 {
695 	struct proc_info_list *list = lookup_processor_type(midr);
696 
697 	if (!list) {
698 		pr_err("CPU%u: configuration botched (ID %08x), CPU halted\n",
699 		       smp_processor_id(), midr);
700 		while (1)
701 		/* can't use cpu_relax() here as it may require MMU setup */;
702 	}
703 
704 	return list;
705 }
706 
707 static void __init setup_processor(void)
708 {
709 	unsigned int midr = read_cpuid_id();
710 	struct proc_info_list *list = lookup_processor(midr);
711 
712 	cpu_name = list->cpu_name;
713 	__cpu_architecture = __get_cpu_architecture();
714 
715 	init_proc_vtable(list->proc);
716 #ifdef MULTI_TLB
717 	cpu_tlb = *list->tlb;
718 #endif
719 #ifdef MULTI_USER
720 	cpu_user = *list->user;
721 #endif
722 #ifdef MULTI_CACHE
723 	cpu_cache = *list->cache;
724 #endif
725 
726 	pr_info("CPU: %s [%08x] revision %d (ARMv%s), cr=%08lx\n",
727 		list->cpu_name, midr, midr & 15,
728 		proc_arch[cpu_architecture()], get_cr());
729 
730 	snprintf(init_utsname()->machine, __NEW_UTS_LEN + 1, "%s%c",
731 		 list->arch_name, ENDIANNESS);
732 	snprintf(elf_platform, ELF_PLATFORM_SIZE, "%s%c",
733 		 list->elf_name, ENDIANNESS);
734 	elf_hwcap = list->elf_hwcap;
735 
736 	cpuid_init_hwcaps();
737 	patch_aeabi_idiv();
738 
739 #ifndef CONFIG_ARM_THUMB
740 	elf_hwcap &= ~(HWCAP_THUMB | HWCAP_IDIVT);
741 #endif
742 #ifdef CONFIG_MMU
743 	init_default_cache_policy(list->__cpu_mm_mmu_flags);
744 #endif
745 	erratum_a15_798181_init();
746 
747 	elf_hwcap_fixup();
748 
749 	cacheid_init();
750 	cpu_init();
751 }
752 
753 void __init dump_machine_table(void)
754 {
755 	const struct machine_desc *p;
756 
757 	early_print("Available machine support:\n\nID (hex)\tNAME\n");
758 	for_each_machine_desc(p)
759 		early_print("%08x\t%s\n", p->nr, p->name);
760 
761 	early_print("\nPlease check your kernel config and/or bootloader.\n");
762 
763 	while (true)
764 		/* can't use cpu_relax() here as it may require MMU setup */;
765 }
766 
767 int __init arm_add_memory(u64 start, u64 size)
768 {
769 	u64 aligned_start;
770 
771 	/*
772 	 * Ensure that start/size are aligned to a page boundary.
773 	 * Size is rounded down, start is rounded up.
774 	 */
775 	aligned_start = PAGE_ALIGN(start);
776 	if (aligned_start > start + size)
777 		size = 0;
778 	else
779 		size -= aligned_start - start;
780 
781 #ifndef CONFIG_PHYS_ADDR_T_64BIT
782 	if (aligned_start > ULONG_MAX) {
783 		pr_crit("Ignoring memory at 0x%08llx outside 32-bit physical address space\n",
784 			start);
785 		return -EINVAL;
786 	}
787 
788 	if (aligned_start + size > ULONG_MAX) {
789 		pr_crit("Truncating memory at 0x%08llx to fit in 32-bit physical address space\n",
790 			(long long)start);
791 		/*
792 		 * To ensure bank->start + bank->size is representable in
793 		 * 32 bits, we use ULONG_MAX as the upper limit rather than 4GB.
794 		 * This means we lose a page after masking.
795 		 */
796 		size = ULONG_MAX - aligned_start;
797 	}
798 #endif
799 
800 	if (aligned_start < PHYS_OFFSET) {
801 		if (aligned_start + size <= PHYS_OFFSET) {
802 			pr_info("Ignoring memory below PHYS_OFFSET: 0x%08llx-0x%08llx\n",
803 				aligned_start, aligned_start + size);
804 			return -EINVAL;
805 		}
806 
807 		pr_info("Ignoring memory below PHYS_OFFSET: 0x%08llx-0x%08llx\n",
808 			aligned_start, (u64)PHYS_OFFSET);
809 
810 		size -= PHYS_OFFSET - aligned_start;
811 		aligned_start = PHYS_OFFSET;
812 	}
813 
814 	start = aligned_start;
815 	size = size & ~(phys_addr_t)(PAGE_SIZE - 1);
816 
817 	/*
818 	 * Check whether this memory region has non-zero size or
819 	 * invalid node number.
820 	 */
821 	if (size == 0)
822 		return -EINVAL;
823 
824 	memblock_add(start, size);
825 	return 0;
826 }
827 
828 /*
829  * Pick out the memory size.  We look for mem=size@start,
830  * where start and size are "size[KkMm]"
831  */
832 
833 static int __init early_mem(char *p)
834 {
835 	static int usermem __initdata = 0;
836 	u64 size;
837 	u64 start;
838 	char *endp;
839 
840 	/*
841 	 * If the user specifies memory size, we
842 	 * blow away any automatically generated
843 	 * size.
844 	 */
845 	if (usermem == 0) {
846 		usermem = 1;
847 		memblock_remove(memblock_start_of_DRAM(),
848 			memblock_end_of_DRAM() - memblock_start_of_DRAM());
849 	}
850 
851 	start = PHYS_OFFSET;
852 	size  = memparse(p, &endp);
853 	if (*endp == '@')
854 		start = memparse(endp + 1, NULL);
855 
856 	arm_add_memory(start, size);
857 
858 	return 0;
859 }
860 early_param("mem", early_mem);
861 
862 static void __init request_standard_resources(const struct machine_desc *mdesc)
863 {
864 	phys_addr_t start, end, res_end;
865 	struct resource *res;
866 	u64 i;
867 
868 	kernel_code.start   = virt_to_phys(_text);
869 	kernel_code.end     = virt_to_phys(__init_begin - 1);
870 	kernel_data.start   = virt_to_phys(_sdata);
871 	kernel_data.end     = virt_to_phys(_end - 1);
872 
873 	for_each_mem_range(i, &start, &end) {
874 		unsigned long boot_alias_start;
875 
876 		/*
877 		 * In memblock, end points to the first byte after the
878 		 * range while in resourses, end points to the last byte in
879 		 * the range.
880 		 */
881 		res_end = end - 1;
882 
883 		/*
884 		 * Some systems have a special memory alias which is only
885 		 * used for booting.  We need to advertise this region to
886 		 * kexec-tools so they know where bootable RAM is located.
887 		 */
888 		boot_alias_start = phys_to_idmap(start);
889 		if (arm_has_idmap_alias() && boot_alias_start != IDMAP_INVALID_ADDR) {
890 			res = memblock_alloc(sizeof(*res), SMP_CACHE_BYTES);
891 			if (!res)
892 				panic("%s: Failed to allocate %zu bytes\n",
893 				      __func__, sizeof(*res));
894 			res->name = "System RAM (boot alias)";
895 			res->start = boot_alias_start;
896 			res->end = phys_to_idmap(res_end);
897 			res->flags = IORESOURCE_MEM | IORESOURCE_BUSY;
898 			request_resource(&iomem_resource, res);
899 		}
900 
901 		res = memblock_alloc(sizeof(*res), SMP_CACHE_BYTES);
902 		if (!res)
903 			panic("%s: Failed to allocate %zu bytes\n", __func__,
904 			      sizeof(*res));
905 		res->name  = "System RAM";
906 		res->start = start;
907 		res->end = res_end;
908 		res->flags = IORESOURCE_SYSTEM_RAM | IORESOURCE_BUSY;
909 
910 		request_resource(&iomem_resource, res);
911 
912 		if (kernel_code.start >= res->start &&
913 		    kernel_code.end <= res->end)
914 			request_resource(res, &kernel_code);
915 		if (kernel_data.start >= res->start &&
916 		    kernel_data.end <= res->end)
917 			request_resource(res, &kernel_data);
918 	}
919 
920 	if (mdesc->video_start) {
921 		video_ram.start = mdesc->video_start;
922 		video_ram.end   = mdesc->video_end;
923 		request_resource(&iomem_resource, &video_ram);
924 	}
925 
926 	/*
927 	 * Some machines don't have the possibility of ever
928 	 * possessing lp0, lp1 or lp2
929 	 */
930 	if (mdesc->reserve_lp0)
931 		request_resource(&ioport_resource, &lp0);
932 	if (mdesc->reserve_lp1)
933 		request_resource(&ioport_resource, &lp1);
934 	if (mdesc->reserve_lp2)
935 		request_resource(&ioport_resource, &lp2);
936 }
937 
938 #if defined(CONFIG_VGA_CONSOLE) || defined(CONFIG_DUMMY_CONSOLE) || \
939     defined(CONFIG_EFI)
940 struct screen_info screen_info = {
941  .orig_video_lines	= 30,
942  .orig_video_cols	= 80,
943  .orig_video_mode	= 0,
944  .orig_video_ega_bx	= 0,
945  .orig_video_isVGA	= 1,
946  .orig_video_points	= 8
947 };
948 #endif
949 
950 static int __init customize_machine(void)
951 {
952 	/*
953 	 * customizes platform devices, or adds new ones
954 	 * On DT based machines, we fall back to populating the
955 	 * machine from the device tree, if no callback is provided,
956 	 * otherwise we would always need an init_machine callback.
957 	 */
958 	if (machine_desc->init_machine)
959 		machine_desc->init_machine();
960 
961 	return 0;
962 }
963 arch_initcall(customize_machine);
964 
965 static int __init init_machine_late(void)
966 {
967 	struct device_node *root;
968 	int ret;
969 
970 	if (machine_desc->init_late)
971 		machine_desc->init_late();
972 
973 	root = of_find_node_by_path("/");
974 	if (root) {
975 		ret = of_property_read_string(root, "serial-number",
976 					      &system_serial);
977 		if (ret)
978 			system_serial = NULL;
979 	}
980 
981 	if (!system_serial)
982 		system_serial = kasprintf(GFP_KERNEL, "%08x%08x",
983 					  system_serial_high,
984 					  system_serial_low);
985 
986 	return 0;
987 }
988 late_initcall(init_machine_late);
989 
990 #ifdef CONFIG_KEXEC
991 /*
992  * The crash region must be aligned to 128MB to avoid
993  * zImage relocating below the reserved region.
994  */
995 #define CRASH_ALIGN	(128 << 20)
996 
997 static inline unsigned long long get_total_mem(void)
998 {
999 	unsigned long total;
1000 
1001 	total = max_low_pfn - min_low_pfn;
1002 	return total << PAGE_SHIFT;
1003 }
1004 
1005 /**
1006  * reserve_crashkernel() - reserves memory are for crash kernel
1007  *
1008  * This function reserves memory area given in "crashkernel=" kernel command
1009  * line parameter. The memory reserved is used by a dump capture kernel when
1010  * primary kernel is crashing.
1011  */
1012 static void __init reserve_crashkernel(void)
1013 {
1014 	unsigned long long crash_size, crash_base;
1015 	unsigned long long total_mem;
1016 	int ret;
1017 
1018 	total_mem = get_total_mem();
1019 	ret = parse_crashkernel(boot_command_line, total_mem,
1020 				&crash_size, &crash_base);
1021 	/* invalid value specified or crashkernel=0 */
1022 	if (ret || !crash_size)
1023 		return;
1024 
1025 	if (crash_base <= 0) {
1026 		unsigned long long crash_max = idmap_to_phys((u32)~0);
1027 		unsigned long long lowmem_max = __pa(high_memory - 1) + 1;
1028 		if (crash_max > lowmem_max)
1029 			crash_max = lowmem_max;
1030 
1031 		crash_base = memblock_phys_alloc_range(crash_size, CRASH_ALIGN,
1032 						       CRASH_ALIGN, crash_max);
1033 		if (!crash_base) {
1034 			pr_err("crashkernel reservation failed - No suitable area found.\n");
1035 			return;
1036 		}
1037 	} else {
1038 		unsigned long long crash_max = crash_base + crash_size;
1039 		unsigned long long start;
1040 
1041 		start = memblock_phys_alloc_range(crash_size, SECTION_SIZE,
1042 						  crash_base, crash_max);
1043 		if (!start) {
1044 			pr_err("crashkernel reservation failed - memory is in use.\n");
1045 			return;
1046 		}
1047 	}
1048 
1049 	pr_info("Reserving %ldMB of memory at %ldMB for crashkernel (System RAM: %ldMB)\n",
1050 		(unsigned long)(crash_size >> 20),
1051 		(unsigned long)(crash_base >> 20),
1052 		(unsigned long)(total_mem >> 20));
1053 
1054 	/* The crashk resource must always be located in normal mem */
1055 	crashk_res.start = crash_base;
1056 	crashk_res.end = crash_base + crash_size - 1;
1057 	insert_resource(&iomem_resource, &crashk_res);
1058 
1059 	if (arm_has_idmap_alias()) {
1060 		/*
1061 		 * If we have a special RAM alias for use at boot, we
1062 		 * need to advertise to kexec tools where the alias is.
1063 		 */
1064 		static struct resource crashk_boot_res = {
1065 			.name = "Crash kernel (boot alias)",
1066 			.flags = IORESOURCE_BUSY | IORESOURCE_MEM,
1067 		};
1068 
1069 		crashk_boot_res.start = phys_to_idmap(crash_base);
1070 		crashk_boot_res.end = crashk_boot_res.start + crash_size - 1;
1071 		insert_resource(&iomem_resource, &crashk_boot_res);
1072 	}
1073 }
1074 #else
1075 static inline void reserve_crashkernel(void) {}
1076 #endif /* CONFIG_KEXEC */
1077 
1078 void __init hyp_mode_check(void)
1079 {
1080 #ifdef CONFIG_ARM_VIRT_EXT
1081 	sync_boot_mode();
1082 
1083 	if (is_hyp_mode_available()) {
1084 		pr_info("CPU: All CPU(s) started in HYP mode.\n");
1085 		pr_info("CPU: Virtualization extensions available.\n");
1086 	} else if (is_hyp_mode_mismatched()) {
1087 		pr_warn("CPU: WARNING: CPU(s) started in wrong/inconsistent modes (primary CPU mode 0x%x)\n",
1088 			__boot_cpu_mode & MODE_MASK);
1089 		pr_warn("CPU: This may indicate a broken bootloader or firmware.\n");
1090 	} else
1091 		pr_info("CPU: All CPU(s) started in SVC mode.\n");
1092 #endif
1093 }
1094 
1095 static void (*__arm_pm_restart)(enum reboot_mode reboot_mode, const char *cmd);
1096 
1097 static int arm_restart(struct notifier_block *nb, unsigned long action,
1098 		       void *data)
1099 {
1100 	__arm_pm_restart(action, data);
1101 	return NOTIFY_DONE;
1102 }
1103 
1104 static struct notifier_block arm_restart_nb = {
1105 	.notifier_call = arm_restart,
1106 	.priority = 128,
1107 };
1108 
1109 void __init setup_arch(char **cmdline_p)
1110 {
1111 	const struct machine_desc *mdesc = NULL;
1112 	void *atags_vaddr = NULL;
1113 
1114 	if (__atags_pointer)
1115 		atags_vaddr = FDT_VIRT_BASE(__atags_pointer);
1116 
1117 	setup_processor();
1118 	if (atags_vaddr) {
1119 		mdesc = setup_machine_fdt(atags_vaddr);
1120 		if (mdesc)
1121 			memblock_reserve(__atags_pointer,
1122 					 fdt_totalsize(atags_vaddr));
1123 	}
1124 	if (!mdesc)
1125 		mdesc = setup_machine_tags(atags_vaddr, __machine_arch_type);
1126 	if (!mdesc) {
1127 		early_print("\nError: invalid dtb and unrecognized/unsupported machine ID\n");
1128 		early_print("  r1=0x%08x, r2=0x%08x\n", __machine_arch_type,
1129 			    __atags_pointer);
1130 		if (__atags_pointer)
1131 			early_print("  r2[]=%*ph\n", 16, atags_vaddr);
1132 		dump_machine_table();
1133 	}
1134 
1135 	machine_desc = mdesc;
1136 	machine_name = mdesc->name;
1137 	dump_stack_set_arch_desc("%s", mdesc->name);
1138 
1139 	if (mdesc->reboot_mode != REBOOT_HARD)
1140 		reboot_mode = mdesc->reboot_mode;
1141 
1142 	setup_initial_init_mm(_text, _etext, _edata, _end);
1143 
1144 	/* populate cmd_line too for later use, preserving boot_command_line */
1145 	strlcpy(cmd_line, boot_command_line, COMMAND_LINE_SIZE);
1146 	*cmdline_p = cmd_line;
1147 
1148 	early_fixmap_init();
1149 	early_ioremap_init();
1150 
1151 	parse_early_param();
1152 
1153 #ifdef CONFIG_MMU
1154 	early_mm_init(mdesc);
1155 #endif
1156 	setup_dma_zone(mdesc);
1157 	xen_early_init();
1158 	arm_efi_init();
1159 	/*
1160 	 * Make sure the calculation for lowmem/highmem is set appropriately
1161 	 * before reserving/allocating any memory
1162 	 */
1163 	adjust_lowmem_bounds();
1164 	arm_memblock_init(mdesc);
1165 	/* Memory may have been removed so recalculate the bounds. */
1166 	adjust_lowmem_bounds();
1167 
1168 	early_ioremap_reset();
1169 
1170 	paging_init(mdesc);
1171 	kasan_init();
1172 	request_standard_resources(mdesc);
1173 
1174 	if (mdesc->restart) {
1175 		__arm_pm_restart = mdesc->restart;
1176 		register_restart_handler(&arm_restart_nb);
1177 	}
1178 
1179 	unflatten_device_tree();
1180 
1181 	arm_dt_init_cpu_maps();
1182 	psci_dt_init();
1183 #ifdef CONFIG_SMP
1184 	if (is_smp()) {
1185 		if (!mdesc->smp_init || !mdesc->smp_init()) {
1186 			if (psci_smp_available())
1187 				smp_set_ops(&psci_smp_ops);
1188 			else if (mdesc->smp)
1189 				smp_set_ops(mdesc->smp);
1190 		}
1191 		smp_init_cpus();
1192 		smp_build_mpidr_hash();
1193 	}
1194 #endif
1195 
1196 	if (!is_smp())
1197 		hyp_mode_check();
1198 
1199 	reserve_crashkernel();
1200 
1201 #ifdef CONFIG_GENERIC_IRQ_MULTI_HANDLER
1202 	handle_arch_irq = mdesc->handle_irq;
1203 #endif
1204 
1205 #ifdef CONFIG_VT
1206 #if defined(CONFIG_VGA_CONSOLE)
1207 	conswitchp = &vga_con;
1208 #endif
1209 #endif
1210 
1211 	if (mdesc->init_early)
1212 		mdesc->init_early();
1213 }
1214 
1215 
1216 static int __init topology_init(void)
1217 {
1218 	int cpu;
1219 
1220 	for_each_possible_cpu(cpu) {
1221 		struct cpuinfo_arm *cpuinfo = &per_cpu(cpu_data, cpu);
1222 		cpuinfo->cpu.hotpluggable = platform_can_hotplug_cpu(cpu);
1223 		register_cpu(&cpuinfo->cpu, cpu);
1224 	}
1225 
1226 	return 0;
1227 }
1228 subsys_initcall(topology_init);
1229 
1230 #ifdef CONFIG_HAVE_PROC_CPU
1231 static int __init proc_cpu_init(void)
1232 {
1233 	struct proc_dir_entry *res;
1234 
1235 	res = proc_mkdir("cpu", NULL);
1236 	if (!res)
1237 		return -ENOMEM;
1238 	return 0;
1239 }
1240 fs_initcall(proc_cpu_init);
1241 #endif
1242 
1243 static const char *hwcap_str[] = {
1244 	"swp",
1245 	"half",
1246 	"thumb",
1247 	"26bit",
1248 	"fastmult",
1249 	"fpa",
1250 	"vfp",
1251 	"edsp",
1252 	"java",
1253 	"iwmmxt",
1254 	"crunch",
1255 	"thumbee",
1256 	"neon",
1257 	"vfpv3",
1258 	"vfpv3d16",
1259 	"tls",
1260 	"vfpv4",
1261 	"idiva",
1262 	"idivt",
1263 	"vfpd32",
1264 	"lpae",
1265 	"evtstrm",
1266 	"fphp",
1267 	"asimdhp",
1268 	"asimddp",
1269 	"asimdfhm",
1270 	"asimdbf16",
1271 	"i8mm",
1272 	NULL
1273 };
1274 
1275 static const char *hwcap2_str[] = {
1276 	"aes",
1277 	"pmull",
1278 	"sha1",
1279 	"sha2",
1280 	"crc32",
1281 	"sb",
1282 	"ssbs",
1283 	NULL
1284 };
1285 
1286 static int c_show(struct seq_file *m, void *v)
1287 {
1288 	int i, j;
1289 	u32 cpuid;
1290 
1291 	for_each_online_cpu(i) {
1292 		/*
1293 		 * glibc reads /proc/cpuinfo to determine the number of
1294 		 * online processors, looking for lines beginning with
1295 		 * "processor".  Give glibc what it expects.
1296 		 */
1297 		seq_printf(m, "processor\t: %d\n", i);
1298 		cpuid = is_smp() ? per_cpu(cpu_data, i).cpuid : read_cpuid_id();
1299 		seq_printf(m, "model name\t: %s rev %d (%s)\n",
1300 			   cpu_name, cpuid & 15, elf_platform);
1301 
1302 #if defined(CONFIG_SMP)
1303 		seq_printf(m, "BogoMIPS\t: %lu.%02lu\n",
1304 			   per_cpu(cpu_data, i).loops_per_jiffy / (500000UL/HZ),
1305 			   (per_cpu(cpu_data, i).loops_per_jiffy / (5000UL/HZ)) % 100);
1306 #else
1307 		seq_printf(m, "BogoMIPS\t: %lu.%02lu\n",
1308 			   loops_per_jiffy / (500000/HZ),
1309 			   (loops_per_jiffy / (5000/HZ)) % 100);
1310 #endif
1311 		/* dump out the processor features */
1312 		seq_puts(m, "Features\t: ");
1313 
1314 		for (j = 0; hwcap_str[j]; j++)
1315 			if (elf_hwcap & (1 << j))
1316 				seq_printf(m, "%s ", hwcap_str[j]);
1317 
1318 		for (j = 0; hwcap2_str[j]; j++)
1319 			if (elf_hwcap2 & (1 << j))
1320 				seq_printf(m, "%s ", hwcap2_str[j]);
1321 
1322 		seq_printf(m, "\nCPU implementer\t: 0x%02x\n", cpuid >> 24);
1323 		seq_printf(m, "CPU architecture: %s\n",
1324 			   proc_arch[cpu_architecture()]);
1325 
1326 		if ((cpuid & 0x0008f000) == 0x00000000) {
1327 			/* pre-ARM7 */
1328 			seq_printf(m, "CPU part\t: %07x\n", cpuid >> 4);
1329 		} else {
1330 			if ((cpuid & 0x0008f000) == 0x00007000) {
1331 				/* ARM7 */
1332 				seq_printf(m, "CPU variant\t: 0x%02x\n",
1333 					   (cpuid >> 16) & 127);
1334 			} else {
1335 				/* post-ARM7 */
1336 				seq_printf(m, "CPU variant\t: 0x%x\n",
1337 					   (cpuid >> 20) & 15);
1338 			}
1339 			seq_printf(m, "CPU part\t: 0x%03x\n",
1340 				   (cpuid >> 4) & 0xfff);
1341 		}
1342 		seq_printf(m, "CPU revision\t: %d\n\n", cpuid & 15);
1343 	}
1344 
1345 	seq_printf(m, "Hardware\t: %s\n", machine_name);
1346 	seq_printf(m, "Revision\t: %04x\n", system_rev);
1347 	seq_printf(m, "Serial\t\t: %s\n", system_serial);
1348 
1349 	return 0;
1350 }
1351 
1352 static void *c_start(struct seq_file *m, loff_t *pos)
1353 {
1354 	return *pos < 1 ? (void *)1 : NULL;
1355 }
1356 
1357 static void *c_next(struct seq_file *m, void *v, loff_t *pos)
1358 {
1359 	++*pos;
1360 	return NULL;
1361 }
1362 
1363 static void c_stop(struct seq_file *m, void *v)
1364 {
1365 }
1366 
1367 const struct seq_operations cpuinfo_op = {
1368 	.start	= c_start,
1369 	.next	= c_next,
1370 	.stop	= c_stop,
1371 	.show	= c_show
1372 };
1373