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v6.13.7
   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/init.h>
  19#include <linux/kexec.h>
  20#include <linux/libfdt.h>
  21#include <linux/of.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)
  68char fpe_type[8];
  69
  70static 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
 
 
 
 
 
 
 
  79unsigned int processor_id;
  80EXPORT_SYMBOL(processor_id);
  81unsigned int __machine_arch_type __read_mostly;
  82EXPORT_SYMBOL(__machine_arch_type);
  83unsigned int cacheid __read_mostly;
  84EXPORT_SYMBOL(cacheid);
  85
  86unsigned int __atags_pointer __initdata;
  87
  88unsigned int system_rev;
  89EXPORT_SYMBOL(system_rev);
  90
  91const char *system_serial;
  92EXPORT_SYMBOL(system_serial);
  93
  94unsigned int system_serial_low;
  95EXPORT_SYMBOL(system_serial_low);
  96
  97unsigned int system_serial_high;
  98EXPORT_SYMBOL(system_serial_high);
  99
 100unsigned int elf_hwcap __read_mostly;
 101EXPORT_SYMBOL(elf_hwcap);
 102
 103unsigned int elf_hwcap2 __read_mostly;
 104EXPORT_SYMBOL(elf_hwcap2);
 105
 106
 107#ifdef MULTI_CPU
 108struct processor processor __ro_after_init;
 109#if defined(CONFIG_BIG_LITTLE) && defined(CONFIG_HARDEN_BRANCH_PREDICTOR)
 110struct processor *cpu_vtable[NR_CPUS] = {
 111	[0] = &processor,
 112};
 113#endif
 114#endif
 115#ifdef MULTI_TLB
 116struct cpu_tlb_fns cpu_tlb __ro_after_init;
 117#endif
 118#ifdef MULTI_USER
 119struct cpu_user_fns cpu_user __ro_after_init;
 120#endif
 121#ifdef MULTI_CACHE
 122struct cpu_cache_fns cpu_cache __ro_after_init;
 123#endif
 124#ifdef CONFIG_OUTER_CACHE
 125struct outer_cache_fns outer_cache __ro_after_init;
 126EXPORT_SYMBOL(outer_cache);
 127#endif
 128
 129/*
 130 * Cached cpu_architecture() result for use by assembler code.
 131 * C code should use the cpu_architecture() function instead of accessing this
 132 * variable directly.
 133 */
 134int __cpu_architecture __read_mostly = CPU_ARCH_UNKNOWN;
 135
 136struct stack {
 137	u32 irq[4];
 138	u32 abt[4];
 139	u32 und[4];
 140	u32 fiq[4];
 141} ____cacheline_aligned;
 142
 143#ifndef CONFIG_CPU_V7M
 144static struct stack stacks[NR_CPUS];
 145#endif
 146
 147char elf_platform[ELF_PLATFORM_SIZE];
 148EXPORT_SYMBOL(elf_platform);
 149
 150static const char *cpu_name;
 151static const char *machine_name;
 152static char __initdata cmd_line[COMMAND_LINE_SIZE];
 153const struct machine_desc *machine_desc __initdata;
 154
 155static union { char c[4]; unsigned long l; } endian_test __initdata = { { 'l', '?', '?', 'b' } };
 156#define ENDIANNESS ((char)endian_test.l)
 157
 158DEFINE_PER_CPU(struct cpuinfo_arm, cpu_data);
 159
 160/*
 161 * Standard memory resources
 162 */
 163static struct resource mem_res[] = {
 164	{
 165		.name = "Video RAM",
 166		.start = 0,
 167		.end = 0,
 168		.flags = IORESOURCE_MEM
 169	},
 170	{
 171		.name = "Kernel code",
 172		.start = 0,
 173		.end = 0,
 174		.flags = IORESOURCE_SYSTEM_RAM
 175	},
 176	{
 177		.name = "Kernel data",
 178		.start = 0,
 179		.end = 0,
 180		.flags = IORESOURCE_SYSTEM_RAM
 181	}
 182};
 183
 184#define video_ram   mem_res[0]
 185#define kernel_code mem_res[1]
 186#define kernel_data mem_res[2]
 187
 188static struct resource io_res[] = {
 189	{
 190		.name = "reserved",
 191		.start = 0x3bc,
 192		.end = 0x3be,
 193		.flags = IORESOURCE_IO | IORESOURCE_BUSY
 194	},
 195	{
 196		.name = "reserved",
 197		.start = 0x378,
 198		.end = 0x37f,
 199		.flags = IORESOURCE_IO | IORESOURCE_BUSY
 200	},
 201	{
 202		.name = "reserved",
 203		.start = 0x278,
 204		.end = 0x27f,
 205		.flags = IORESOURCE_IO | IORESOURCE_BUSY
 206	}
 207};
 208
 209#define lp0 io_res[0]
 210#define lp1 io_res[1]
 211#define lp2 io_res[2]
 212
 213static const char *proc_arch[] = {
 214	"undefined/unknown",
 215	"3",
 216	"4",
 217	"4T",
 218	"5",
 219	"5T",
 220	"5TE",
 221	"5TEJ",
 222	"6TEJ",
 223	"7",
 224	"7M",
 225	"?(12)",
 226	"?(13)",
 227	"?(14)",
 228	"?(15)",
 229	"?(16)",
 230	"?(17)",
 231};
 232
 233#ifdef CONFIG_CPU_V7M
 234static int __get_cpu_architecture(void)
 235{
 236	return CPU_ARCH_ARMv7M;
 237}
 238#else
 239static int __get_cpu_architecture(void)
 240{
 241	int cpu_arch;
 242
 243	if ((read_cpuid_id() & 0x0008f000) == 0) {
 244		cpu_arch = CPU_ARCH_UNKNOWN;
 245	} else if ((read_cpuid_id() & 0x0008f000) == 0x00007000) {
 246		cpu_arch = (read_cpuid_id() & (1 << 23)) ? CPU_ARCH_ARMv4T : CPU_ARCH_ARMv3;
 247	} else if ((read_cpuid_id() & 0x00080000) == 0x00000000) {
 248		cpu_arch = (read_cpuid_id() >> 16) & 7;
 249		if (cpu_arch)
 250			cpu_arch += CPU_ARCH_ARMv3;
 251	} else if ((read_cpuid_id() & 0x000f0000) == 0x000f0000) {
 252		/* Revised CPUID format. Read the Memory Model Feature
 253		 * Register 0 and check for VMSAv7 or PMSAv7 */
 254		unsigned int mmfr0 = read_cpuid_ext(CPUID_EXT_MMFR0);
 255		if ((mmfr0 & 0x0000000f) >= 0x00000003 ||
 256		    (mmfr0 & 0x000000f0) >= 0x00000030)
 257			cpu_arch = CPU_ARCH_ARMv7;
 258		else if ((mmfr0 & 0x0000000f) == 0x00000002 ||
 259			 (mmfr0 & 0x000000f0) == 0x00000020)
 260			cpu_arch = CPU_ARCH_ARMv6;
 261		else
 262			cpu_arch = CPU_ARCH_UNKNOWN;
 263	} else
 264		cpu_arch = CPU_ARCH_UNKNOWN;
 265
 266	return cpu_arch;
 267}
 268#endif
 269
 270int __pure cpu_architecture(void)
 271{
 272	BUG_ON(__cpu_architecture == CPU_ARCH_UNKNOWN);
 273
 274	return __cpu_architecture;
 275}
 276
 277static int cpu_has_aliasing_icache(unsigned int arch)
 278{
 279	int aliasing_icache;
 280	unsigned int id_reg, num_sets, line_size;
 281
 282	/* PIPT caches never alias. */
 283	if (icache_is_pipt())
 284		return 0;
 285
 286	/* arch specifies the register format */
 287	switch (arch) {
 288	case CPU_ARCH_ARMv7:
 289		set_csselr(CSSELR_ICACHE | CSSELR_L1);
 290		isb();
 291		id_reg = read_ccsidr();
 292		line_size = 4 << ((id_reg & 0x7) + 2);
 293		num_sets = ((id_reg >> 13) & 0x7fff) + 1;
 294		aliasing_icache = (line_size * num_sets) > PAGE_SIZE;
 295		break;
 296	case CPU_ARCH_ARMv6:
 297		aliasing_icache = read_cpuid_cachetype() & (1 << 11);
 298		break;
 299	default:
 300		/* I-cache aliases will be handled by D-cache aliasing code */
 301		aliasing_icache = 0;
 302	}
 303
 304	return aliasing_icache;
 305}
 306
 307static void __init cacheid_init(void)
 308{
 309	unsigned int arch = cpu_architecture();
 310
 311	if (arch >= CPU_ARCH_ARMv6) {
 312		unsigned int cachetype = read_cpuid_cachetype();
 313
 314		if ((arch == CPU_ARCH_ARMv7M) && !(cachetype & 0xf000f)) {
 315			cacheid = 0;
 316		} else if ((cachetype & (7 << 29)) == 4 << 29) {
 317			/* ARMv7 register format */
 318			arch = CPU_ARCH_ARMv7;
 319			cacheid = CACHEID_VIPT_NONALIASING;
 320			switch (cachetype & (3 << 14)) {
 321			case (1 << 14):
 322				cacheid |= CACHEID_ASID_TAGGED;
 323				break;
 324			case (3 << 14):
 325				cacheid |= CACHEID_PIPT;
 326				break;
 327			}
 328		} else {
 329			arch = CPU_ARCH_ARMv6;
 330			if (cachetype & (1 << 23))
 331				cacheid = CACHEID_VIPT_ALIASING;
 332			else
 333				cacheid = CACHEID_VIPT_NONALIASING;
 334		}
 335		if (cpu_has_aliasing_icache(arch))
 336			cacheid |= CACHEID_VIPT_I_ALIASING;
 337	} else {
 338		cacheid = CACHEID_VIVT;
 339	}
 340
 341	pr_info("CPU: %s data cache, %s instruction cache\n",
 342		cache_is_vivt() ? "VIVT" :
 343		cache_is_vipt_aliasing() ? "VIPT aliasing" :
 344		cache_is_vipt_nonaliasing() ? "PIPT / VIPT nonaliasing" : "unknown",
 345		cache_is_vivt() ? "VIVT" :
 346		icache_is_vivt_asid_tagged() ? "VIVT ASID tagged" :
 347		icache_is_vipt_aliasing() ? "VIPT aliasing" :
 348		icache_is_pipt() ? "PIPT" :
 349		cache_is_vipt_nonaliasing() ? "VIPT nonaliasing" : "unknown");
 350}
 351
 352/*
 353 * These functions re-use the assembly code in head.S, which
 354 * already provide the required functionality.
 355 */
 356extern struct proc_info_list *lookup_processor_type(unsigned int);
 357
 358void __init early_print(const char *str, ...)
 359{
 360	extern void printascii(const char *);
 361	char buf[256];
 362	va_list ap;
 363
 364	va_start(ap, str);
 365	vsnprintf(buf, sizeof(buf), str, ap);
 366	va_end(ap);
 367
 368#ifdef CONFIG_DEBUG_LL
 369	printascii(buf);
 370#endif
 371	printk("%s", buf);
 372}
 373
 374#ifdef CONFIG_ARM_PATCH_IDIV
 375
 376static inline u32 __attribute_const__ sdiv_instruction(void)
 377{
 378	if (IS_ENABLED(CONFIG_THUMB2_KERNEL)) {
 379		/* "sdiv r0, r0, r1" */
 380		u32 insn = __opcode_thumb32_compose(0xfb90, 0xf0f1);
 381		return __opcode_to_mem_thumb32(insn);
 382	}
 383
 384	/* "sdiv r0, r0, r1" */
 385	return __opcode_to_mem_arm(0xe710f110);
 386}
 387
 388static inline u32 __attribute_const__ udiv_instruction(void)
 389{
 390	if (IS_ENABLED(CONFIG_THUMB2_KERNEL)) {
 391		/* "udiv r0, r0, r1" */
 392		u32 insn = __opcode_thumb32_compose(0xfbb0, 0xf0f1);
 393		return __opcode_to_mem_thumb32(insn);
 394	}
 395
 396	/* "udiv r0, r0, r1" */
 397	return __opcode_to_mem_arm(0xe730f110);
 398}
 399
 400static inline u32 __attribute_const__ bx_lr_instruction(void)
 401{
 402	if (IS_ENABLED(CONFIG_THUMB2_KERNEL)) {
 403		/* "bx lr; nop" */
 404		u32 insn = __opcode_thumb32_compose(0x4770, 0x46c0);
 405		return __opcode_to_mem_thumb32(insn);
 406	}
 407
 408	/* "bx lr" */
 409	return __opcode_to_mem_arm(0xe12fff1e);
 410}
 411
 412static void __init patch_aeabi_idiv(void)
 413{
 414	extern void __aeabi_uidiv(void);
 415	extern void __aeabi_idiv(void);
 416	uintptr_t fn_addr;
 417	unsigned int mask;
 418
 419	mask = IS_ENABLED(CONFIG_THUMB2_KERNEL) ? HWCAP_IDIVT : HWCAP_IDIVA;
 420	if (!(elf_hwcap & mask))
 421		return;
 422
 423	pr_info("CPU: div instructions available: patching division code\n");
 424
 425	fn_addr = ((uintptr_t)&__aeabi_uidiv) & ~1;
 426	asm ("" : "+g" (fn_addr));
 427	((u32 *)fn_addr)[0] = udiv_instruction();
 428	((u32 *)fn_addr)[1] = bx_lr_instruction();
 429	flush_icache_range(fn_addr, fn_addr + 8);
 430
 431	fn_addr = ((uintptr_t)&__aeabi_idiv) & ~1;
 432	asm ("" : "+g" (fn_addr));
 433	((u32 *)fn_addr)[0] = sdiv_instruction();
 434	((u32 *)fn_addr)[1] = bx_lr_instruction();
 435	flush_icache_range(fn_addr, fn_addr + 8);
 436}
 437
 438#else
 439static inline void patch_aeabi_idiv(void) { }
 440#endif
 441
 442static void __init cpuid_init_hwcaps(void)
 443{
 444	int block;
 445	u32 isar5;
 446	u32 isar6;
 447	u32 pfr2;
 448
 449	if (cpu_architecture() < CPU_ARCH_ARMv7)
 450		return;
 451
 452	block = cpuid_feature_extract(CPUID_EXT_ISAR0, 24);
 453	if (block >= 2)
 454		elf_hwcap |= HWCAP_IDIVA;
 455	if (block >= 1)
 456		elf_hwcap |= HWCAP_IDIVT;
 457
 458	/* LPAE implies atomic ldrd/strd instructions */
 459	block = cpuid_feature_extract(CPUID_EXT_MMFR0, 0);
 460	if (block >= 5)
 461		elf_hwcap |= HWCAP_LPAE;
 462
 463	/* check for supported v8 Crypto instructions */
 464	isar5 = read_cpuid_ext(CPUID_EXT_ISAR5);
 465
 466	block = cpuid_feature_extract_field(isar5, 4);
 467	if (block >= 2)
 468		elf_hwcap2 |= HWCAP2_PMULL;
 469	if (block >= 1)
 470		elf_hwcap2 |= HWCAP2_AES;
 471
 472	block = cpuid_feature_extract_field(isar5, 8);
 473	if (block >= 1)
 474		elf_hwcap2 |= HWCAP2_SHA1;
 475
 476	block = cpuid_feature_extract_field(isar5, 12);
 477	if (block >= 1)
 478		elf_hwcap2 |= HWCAP2_SHA2;
 479
 480	block = cpuid_feature_extract_field(isar5, 16);
 481	if (block >= 1)
 482		elf_hwcap2 |= HWCAP2_CRC32;
 483
 484	/* Check for Speculation barrier instruction */
 485	isar6 = read_cpuid_ext(CPUID_EXT_ISAR6);
 486	block = cpuid_feature_extract_field(isar6, 12);
 487	if (block >= 1)
 488		elf_hwcap2 |= HWCAP2_SB;
 489
 490	/* Check for Speculative Store Bypassing control */
 491	pfr2 = read_cpuid_ext(CPUID_EXT_PFR2);
 492	block = cpuid_feature_extract_field(pfr2, 4);
 493	if (block >= 1)
 494		elf_hwcap2 |= HWCAP2_SSBS;
 495}
 496
 497static void __init elf_hwcap_fixup(void)
 498{
 499	unsigned id = read_cpuid_id();
 500
 501	/*
 502	 * HWCAP_TLS is available only on 1136 r1p0 and later,
 503	 * see also kuser_get_tls_init.
 504	 */
 505	if (read_cpuid_part() == ARM_CPU_PART_ARM1136 &&
 506	    ((id >> 20) & 3) == 0) {
 507		elf_hwcap &= ~HWCAP_TLS;
 508		return;
 509	}
 510
 511	/* Verify if CPUID scheme is implemented */
 512	if ((id & 0x000f0000) != 0x000f0000)
 513		return;
 514
 515	/*
 516	 * If the CPU supports LDREX/STREX and LDREXB/STREXB,
 517	 * avoid advertising SWP; it may not be atomic with
 518	 * multiprocessing cores.
 519	 */
 520	if (cpuid_feature_extract(CPUID_EXT_ISAR3, 12) > 1 ||
 521	    (cpuid_feature_extract(CPUID_EXT_ISAR3, 12) == 1 &&
 522	     cpuid_feature_extract(CPUID_EXT_ISAR4, 20) >= 3))
 523		elf_hwcap &= ~HWCAP_SWP;
 524}
 525
 526/*
 527 * cpu_init - initialise one CPU.
 528 *
 529 * cpu_init sets up the per-CPU stacks.
 530 */
 531void notrace cpu_init(void)
 532{
 533#ifndef CONFIG_CPU_V7M
 534	unsigned int cpu = smp_processor_id();
 535	struct stack *stk = &stacks[cpu];
 536
 537	if (cpu >= NR_CPUS) {
 538		pr_crit("CPU%u: bad primary CPU number\n", cpu);
 539		BUG();
 540	}
 541
 542	/*
 543	 * This only works on resume and secondary cores. For booting on the
 544	 * boot cpu, smp_prepare_boot_cpu is called after percpu area setup.
 545	 */
 546	set_my_cpu_offset(per_cpu_offset(cpu));
 547
 548	cpu_proc_init();
 549
 550	/*
 551	 * Define the placement constraint for the inline asm directive below.
 552	 * In Thumb-2, msr with an immediate value is not allowed.
 553	 */
 554#ifdef CONFIG_THUMB2_KERNEL
 555#define PLC_l	"l"
 556#define PLC_r	"r"
 557#else
 558#define PLC_l	"I"
 559#define PLC_r	"I"
 560#endif
 561
 562	/*
 563	 * setup stacks for re-entrant exception handlers
 564	 */
 565	__asm__ (
 566	"msr	cpsr_c, %1\n\t"
 567	"add	r14, %0, %2\n\t"
 568	"mov	sp, r14\n\t"
 569	"msr	cpsr_c, %3\n\t"
 570	"add	r14, %0, %4\n\t"
 571	"mov	sp, r14\n\t"
 572	"msr	cpsr_c, %5\n\t"
 573	"add	r14, %0, %6\n\t"
 574	"mov	sp, r14\n\t"
 575	"msr	cpsr_c, %7\n\t"
 576	"add	r14, %0, %8\n\t"
 577	"mov	sp, r14\n\t"
 578	"msr	cpsr_c, %9"
 579	    :
 580	    : "r" (stk),
 581	      PLC_r (PSR_F_BIT | PSR_I_BIT | IRQ_MODE),
 582	      "I" (offsetof(struct stack, irq[0])),
 583	      PLC_r (PSR_F_BIT | PSR_I_BIT | ABT_MODE),
 584	      "I" (offsetof(struct stack, abt[0])),
 585	      PLC_r (PSR_F_BIT | PSR_I_BIT | UND_MODE),
 586	      "I" (offsetof(struct stack, und[0])),
 587	      PLC_r (PSR_F_BIT | PSR_I_BIT | FIQ_MODE),
 588	      "I" (offsetof(struct stack, fiq[0])),
 589	      PLC_l (PSR_F_BIT | PSR_I_BIT | SVC_MODE)
 590	    : "r14");
 591#endif
 592}
 593
 594u32 __cpu_logical_map[NR_CPUS] = { [0 ... NR_CPUS-1] = MPIDR_INVALID };
 595
 596void __init smp_setup_processor_id(void)
 597{
 598	int i;
 599	u32 mpidr = is_smp() ? read_cpuid_mpidr() & MPIDR_HWID_BITMASK : 0;
 600	u32 cpu = MPIDR_AFFINITY_LEVEL(mpidr, 0);
 601
 602	cpu_logical_map(0) = cpu;
 603	for (i = 1; i < nr_cpu_ids; ++i)
 604		cpu_logical_map(i) = i == cpu ? 0 : i;
 605
 606	/*
 607	 * clear __my_cpu_offset on boot CPU to avoid hang caused by
 608	 * using percpu variable early, for example, lockdep will
 609	 * access percpu variable inside lock_release
 610	 */
 611	set_my_cpu_offset(0);
 612
 613	pr_info("Booting Linux on physical CPU 0x%x\n", mpidr);
 614}
 615
 616struct mpidr_hash mpidr_hash;
 617#ifdef CONFIG_SMP
 618/**
 619 * smp_build_mpidr_hash - Pre-compute shifts required at each affinity
 620 *			  level in order to build a linear index from an
 621 *			  MPIDR value. Resulting algorithm is a collision
 622 *			  free hash carried out through shifting and ORing
 623 */
 624static void __init smp_build_mpidr_hash(void)
 625{
 626	u32 i, affinity;
 627	u32 fs[3], bits[3], ls, mask = 0;
 628	/*
 629	 * Pre-scan the list of MPIDRS and filter out bits that do
 630	 * not contribute to affinity levels, ie they never toggle.
 631	 */
 632	for_each_possible_cpu(i)
 633		mask |= (cpu_logical_map(i) ^ cpu_logical_map(0));
 634	pr_debug("mask of set bits 0x%x\n", mask);
 635	/*
 636	 * Find and stash the last and first bit set at all affinity levels to
 637	 * check how many bits are required to represent them.
 638	 */
 639	for (i = 0; i < 3; i++) {
 640		affinity = MPIDR_AFFINITY_LEVEL(mask, i);
 641		/*
 642		 * Find the MSB bit and LSB bits position
 643		 * to determine how many bits are required
 644		 * to express the affinity level.
 645		 */
 646		ls = fls(affinity);
 647		fs[i] = affinity ? ffs(affinity) - 1 : 0;
 648		bits[i] = ls - fs[i];
 649	}
 650	/*
 651	 * An index can be created from the MPIDR by isolating the
 652	 * significant bits at each affinity level and by shifting
 653	 * them in order to compress the 24 bits values space to a
 654	 * compressed set of values. This is equivalent to hashing
 655	 * the MPIDR through shifting and ORing. It is a collision free
 656	 * hash though not minimal since some levels might contain a number
 657	 * of CPUs that is not an exact power of 2 and their bit
 658	 * representation might contain holes, eg MPIDR[7:0] = {0x2, 0x80}.
 659	 */
 660	mpidr_hash.shift_aff[0] = fs[0];
 661	mpidr_hash.shift_aff[1] = MPIDR_LEVEL_BITS + fs[1] - bits[0];
 662	mpidr_hash.shift_aff[2] = 2*MPIDR_LEVEL_BITS + fs[2] -
 663						(bits[1] + bits[0]);
 664	mpidr_hash.mask = mask;
 665	mpidr_hash.bits = bits[2] + bits[1] + bits[0];
 666	pr_debug("MPIDR hash: aff0[%u] aff1[%u] aff2[%u] mask[0x%x] bits[%u]\n",
 667				mpidr_hash.shift_aff[0],
 668				mpidr_hash.shift_aff[1],
 669				mpidr_hash.shift_aff[2],
 670				mpidr_hash.mask,
 671				mpidr_hash.bits);
 672	/*
 673	 * 4x is an arbitrary value used to warn on a hash table much bigger
 674	 * than expected on most systems.
 675	 */
 676	if (mpidr_hash_size() > 4 * num_possible_cpus())
 677		pr_warn("Large number of MPIDR hash buckets detected\n");
 678	sync_cache_w(&mpidr_hash);
 679}
 680#endif
 681
 682/*
 683 * locate processor in the list of supported processor types.  The linker
 684 * builds this table for us from the entries in arch/arm/mm/proc-*.S
 685 */
 686struct proc_info_list *lookup_processor(u32 midr)
 687{
 688	struct proc_info_list *list = lookup_processor_type(midr);
 689
 690	if (!list) {
 691		pr_err("CPU%u: configuration botched (ID %08x), CPU halted\n",
 692		       smp_processor_id(), midr);
 693		while (1)
 694		/* can't use cpu_relax() here as it may require MMU setup */;
 695	}
 696
 697	return list;
 698}
 699
 700static void __init setup_processor(void)
 701{
 702	unsigned int midr = read_cpuid_id();
 703	struct proc_info_list *list = lookup_processor(midr);
 704
 705	cpu_name = list->cpu_name;
 706	__cpu_architecture = __get_cpu_architecture();
 707
 708	init_proc_vtable(list->proc);
 709#ifdef MULTI_TLB
 710	cpu_tlb = *list->tlb;
 711#endif
 712#ifdef MULTI_USER
 713	cpu_user = *list->user;
 714#endif
 715#ifdef MULTI_CACHE
 716	cpu_cache = *list->cache;
 717#endif
 718
 719	pr_info("CPU: %s [%08x] revision %d (ARMv%s), cr=%08lx\n",
 720		list->cpu_name, midr, midr & 15,
 721		proc_arch[cpu_architecture()], get_cr());
 722
 723	snprintf(init_utsname()->machine, __NEW_UTS_LEN + 1, "%s%c",
 724		 list->arch_name, ENDIANNESS);
 725	snprintf(elf_platform, ELF_PLATFORM_SIZE, "%s%c",
 726		 list->elf_name, ENDIANNESS);
 727	elf_hwcap = list->elf_hwcap;
 728
 729	cpuid_init_hwcaps();
 730	patch_aeabi_idiv();
 731
 732#ifndef CONFIG_ARM_THUMB
 733	elf_hwcap &= ~(HWCAP_THUMB | HWCAP_IDIVT);
 734#endif
 735#ifdef CONFIG_MMU
 736	init_default_cache_policy(list->__cpu_mm_mmu_flags);
 737#endif
 738	erratum_a15_798181_init();
 739
 740	elf_hwcap_fixup();
 741
 742	cacheid_init();
 743	cpu_init();
 744}
 745
 746void __init dump_machine_table(void)
 747{
 748	const struct machine_desc *p;
 749
 750	early_print("Available machine support:\n\nID (hex)\tNAME\n");
 751	for_each_machine_desc(p)
 752		early_print("%08x\t%s\n", p->nr, p->name);
 753
 754	early_print("\nPlease check your kernel config and/or bootloader.\n");
 755
 756	while (true)
 757		/* can't use cpu_relax() here as it may require MMU setup */;
 758}
 759
 760int __init arm_add_memory(u64 start, u64 size)
 761{
 762	u64 aligned_start;
 763
 764	/*
 765	 * Ensure that start/size are aligned to a page boundary.
 766	 * Size is rounded down, start is rounded up.
 767	 */
 768	aligned_start = PAGE_ALIGN(start);
 769	if (aligned_start > start + size)
 770		size = 0;
 771	else
 772		size -= aligned_start - start;
 773
 774#ifndef CONFIG_PHYS_ADDR_T_64BIT
 775	if (aligned_start > ULONG_MAX) {
 776		pr_crit("Ignoring memory at 0x%08llx outside 32-bit physical address space\n",
 777			start);
 778		return -EINVAL;
 779	}
 780
 781	if (aligned_start + size > ULONG_MAX) {
 782		pr_crit("Truncating memory at 0x%08llx to fit in 32-bit physical address space\n",
 783			(long long)start);
 784		/*
 785		 * To ensure bank->start + bank->size is representable in
 786		 * 32 bits, we use ULONG_MAX as the upper limit rather than 4GB.
 787		 * This means we lose a page after masking.
 788		 */
 789		size = ULONG_MAX - aligned_start;
 790	}
 791#endif
 792
 793	if (aligned_start < PHYS_OFFSET) {
 794		if (aligned_start + size <= PHYS_OFFSET) {
 795			pr_info("Ignoring memory below PHYS_OFFSET: 0x%08llx-0x%08llx\n",
 796				aligned_start, aligned_start + size);
 797			return -EINVAL;
 798		}
 799
 800		pr_info("Ignoring memory below PHYS_OFFSET: 0x%08llx-0x%08llx\n",
 801			aligned_start, (u64)PHYS_OFFSET);
 802
 803		size -= PHYS_OFFSET - aligned_start;
 804		aligned_start = PHYS_OFFSET;
 805	}
 806
 807	start = aligned_start;
 808	size = size & ~(phys_addr_t)(PAGE_SIZE - 1);
 809
 810	/*
 811	 * Check whether this memory region has non-zero size or
 812	 * invalid node number.
 813	 */
 814	if (size == 0)
 815		return -EINVAL;
 816
 817	memblock_add(start, size);
 818	return 0;
 819}
 820
 821/*
 822 * Pick out the memory size.  We look for mem=size@start,
 823 * where start and size are "size[KkMm]"
 824 */
 825
 826static int __init early_mem(char *p)
 827{
 828	static int usermem __initdata = 0;
 829	u64 size;
 830	u64 start;
 831	char *endp;
 832
 833	/*
 834	 * If the user specifies memory size, we
 835	 * blow away any automatically generated
 836	 * size.
 837	 */
 838	if (usermem == 0) {
 839		usermem = 1;
 840		memblock_remove(memblock_start_of_DRAM(),
 841			memblock_end_of_DRAM() - memblock_start_of_DRAM());
 842	}
 843
 844	start = PHYS_OFFSET;
 845	size  = memparse(p, &endp);
 846	if (*endp == '@')
 847		start = memparse(endp + 1, NULL);
 848
 849	arm_add_memory(start, size);
 850
 851	return 0;
 852}
 853early_param("mem", early_mem);
 854
 855static void __init request_standard_resources(const struct machine_desc *mdesc)
 856{
 857	phys_addr_t start, end, res_end;
 858	struct resource *res;
 859	u64 i;
 860
 861	kernel_code.start   = virt_to_phys(_text);
 862	kernel_code.end     = virt_to_phys(__init_begin - 1);
 863	kernel_data.start   = virt_to_phys(_sdata);
 864	kernel_data.end     = virt_to_phys(_end - 1);
 865
 866	for_each_mem_range(i, &start, &end) {
 
 
 867		unsigned long boot_alias_start;
 868
 869		/*
 870		 * In memblock, end points to the first byte after the
 871		 * range while in resourses, end points to the last byte in
 872		 * the range.
 873		 */
 874		res_end = end - 1;
 875
 876		/*
 877		 * Some systems have a special memory alias which is only
 878		 * used for booting.  We need to advertise this region to
 879		 * kexec-tools so they know where bootable RAM is located.
 880		 */
 881		boot_alias_start = phys_to_idmap(start);
 882		if (arm_has_idmap_alias() && boot_alias_start != IDMAP_INVALID_ADDR) {
 883			res = memblock_alloc(sizeof(*res), SMP_CACHE_BYTES);
 884			if (!res)
 885				panic("%s: Failed to allocate %zu bytes\n",
 886				      __func__, sizeof(*res));
 887			res->name = "System RAM (boot alias)";
 888			res->start = boot_alias_start;
 889			res->end = phys_to_idmap(res_end);
 890			res->flags = IORESOURCE_MEM | IORESOURCE_BUSY;
 891			request_resource(&iomem_resource, res);
 892		}
 893
 894		res = memblock_alloc(sizeof(*res), SMP_CACHE_BYTES);
 895		if (!res)
 896			panic("%s: Failed to allocate %zu bytes\n", __func__,
 897			      sizeof(*res));
 898		res->name  = "System RAM";
 899		res->start = start;
 900		res->end = res_end;
 901		res->flags = IORESOURCE_SYSTEM_RAM | IORESOURCE_BUSY;
 902
 903		request_resource(&iomem_resource, res);
 904
 905		if (kernel_code.start >= res->start &&
 906		    kernel_code.end <= res->end)
 907			request_resource(res, &kernel_code);
 908		if (kernel_data.start >= res->start &&
 909		    kernel_data.end <= res->end)
 910			request_resource(res, &kernel_data);
 911	}
 912
 913	if (mdesc->video_start) {
 914		video_ram.start = mdesc->video_start;
 915		video_ram.end   = mdesc->video_end;
 916		request_resource(&iomem_resource, &video_ram);
 917	}
 918
 919	/*
 920	 * Some machines don't have the possibility of ever
 921	 * possessing lp0, lp1 or lp2
 922	 */
 923	if (mdesc->reserve_lp0)
 924		request_resource(&ioport_resource, &lp0);
 925	if (mdesc->reserve_lp1)
 926		request_resource(&ioport_resource, &lp1);
 927	if (mdesc->reserve_lp2)
 928		request_resource(&ioport_resource, &lp2);
 929}
 930
 931#if defined(CONFIG_VGA_CONSOLE)
 932struct screen_info vgacon_screen_info = {
 
 933 .orig_video_lines	= 30,
 934 .orig_video_cols	= 80,
 935 .orig_video_mode	= 0,
 936 .orig_video_ega_bx	= 0,
 937 .orig_video_isVGA	= 1,
 938 .orig_video_points	= 8
 939};
 940#endif
 941
 942static int __init customize_machine(void)
 943{
 944	/*
 945	 * customizes platform devices, or adds new ones
 946	 * On DT based machines, we fall back to populating the
 947	 * machine from the device tree, if no callback is provided,
 948	 * otherwise we would always need an init_machine callback.
 949	 */
 950	if (machine_desc->init_machine)
 951		machine_desc->init_machine();
 952
 953	return 0;
 954}
 955arch_initcall(customize_machine);
 956
 957static int __init init_machine_late(void)
 958{
 959	struct device_node *root;
 960	int ret;
 961
 962	if (machine_desc->init_late)
 963		machine_desc->init_late();
 964
 965	root = of_find_node_by_path("/");
 966	if (root) {
 967		ret = of_property_read_string(root, "serial-number",
 968					      &system_serial);
 969		if (ret)
 970			system_serial = NULL;
 971	}
 972
 973	if (!system_serial)
 974		system_serial = kasprintf(GFP_KERNEL, "%08x%08x",
 975					  system_serial_high,
 976					  system_serial_low);
 977
 978	return 0;
 979}
 980late_initcall(init_machine_late);
 981
 982#ifdef CONFIG_CRASH_RESERVE
 983/*
 984 * The crash region must be aligned to 128MB to avoid
 985 * zImage relocating below the reserved region.
 986 */
 987#define CRASH_ALIGN	(128 << 20)
 988
 989static inline unsigned long long get_total_mem(void)
 990{
 991	unsigned long total;
 992
 993	total = max_low_pfn - min_low_pfn;
 994	return total << PAGE_SHIFT;
 995}
 996
 997/**
 998 * reserve_crashkernel() - reserves memory are for crash kernel
 999 *
1000 * This function reserves memory area given in "crashkernel=" kernel command
1001 * line parameter. The memory reserved is used by a dump capture kernel when
1002 * primary kernel is crashing.
1003 */
1004static void __init reserve_crashkernel(void)
1005{
1006	unsigned long long crash_size, crash_base;
1007	unsigned long long total_mem;
1008	int ret;
1009
1010	total_mem = get_total_mem();
1011	ret = parse_crashkernel(boot_command_line, total_mem,
1012				&crash_size, &crash_base,
1013				NULL, NULL);
1014	/* invalid value specified or crashkernel=0 */
1015	if (ret || !crash_size)
1016		return;
1017
1018	if (crash_base <= 0) {
1019		unsigned long long crash_max = idmap_to_phys((u32)~0);
1020		unsigned long long lowmem_max = __pa(high_memory - 1) + 1;
1021		if (crash_max > lowmem_max)
1022			crash_max = lowmem_max;
1023
1024		crash_base = memblock_phys_alloc_range(crash_size, CRASH_ALIGN,
1025						       CRASH_ALIGN, crash_max);
1026		if (!crash_base) {
1027			pr_err("crashkernel reservation failed - No suitable area found.\n");
1028			return;
1029		}
1030	} else {
1031		unsigned long long crash_max = crash_base + crash_size;
1032		unsigned long long start;
1033
1034		start = memblock_phys_alloc_range(crash_size, SECTION_SIZE,
1035						  crash_base, crash_max);
1036		if (!start) {
 
1037			pr_err("crashkernel reservation failed - memory is in use.\n");
1038			return;
1039		}
1040	}
1041
 
 
 
 
 
 
 
1042	pr_info("Reserving %ldMB of memory at %ldMB for crashkernel (System RAM: %ldMB)\n",
1043		(unsigned long)(crash_size >> 20),
1044		(unsigned long)(crash_base >> 20),
1045		(unsigned long)(total_mem >> 20));
1046
1047	/* The crashk resource must always be located in normal mem */
1048	crashk_res.start = crash_base;
1049	crashk_res.end = crash_base + crash_size - 1;
1050	insert_resource(&iomem_resource, &crashk_res);
1051
1052	if (arm_has_idmap_alias()) {
1053		/*
1054		 * If we have a special RAM alias for use at boot, we
1055		 * need to advertise to kexec tools where the alias is.
1056		 */
1057		static struct resource crashk_boot_res = {
1058			.name = "Crash kernel (boot alias)",
1059			.flags = IORESOURCE_BUSY | IORESOURCE_MEM,
1060		};
1061
1062		crashk_boot_res.start = phys_to_idmap(crash_base);
1063		crashk_boot_res.end = crashk_boot_res.start + crash_size - 1;
1064		insert_resource(&iomem_resource, &crashk_boot_res);
1065	}
1066}
1067#else
1068static inline void reserve_crashkernel(void) {}
1069#endif /* CONFIG_CRASH_RESERVE*/
1070
1071void __init hyp_mode_check(void)
1072{
1073#ifdef CONFIG_ARM_VIRT_EXT
1074	sync_boot_mode();
1075
1076	if (is_hyp_mode_available()) {
1077		pr_info("CPU: All CPU(s) started in HYP mode.\n");
1078		pr_info("CPU: Virtualization extensions available.\n");
1079	} else if (is_hyp_mode_mismatched()) {
1080		pr_warn("CPU: WARNING: CPU(s) started in wrong/inconsistent modes (primary CPU mode 0x%x)\n",
1081			__boot_cpu_mode & MODE_MASK);
1082		pr_warn("CPU: This may indicate a broken bootloader or firmware.\n");
1083	} else
1084		pr_info("CPU: All CPU(s) started in SVC mode.\n");
1085#endif
1086}
1087
1088static void (*__arm_pm_restart)(enum reboot_mode reboot_mode, const char *cmd);
1089
1090static int arm_restart(struct notifier_block *nb, unsigned long action,
1091		       void *data)
1092{
1093	__arm_pm_restart(action, data);
1094	return NOTIFY_DONE;
1095}
1096
1097static struct notifier_block arm_restart_nb = {
1098	.notifier_call = arm_restart,
1099	.priority = 128,
1100};
1101
1102void __init setup_arch(char **cmdline_p)
1103{
1104	const struct machine_desc *mdesc = NULL;
1105	void *atags_vaddr = NULL;
1106
1107	if (__atags_pointer)
1108		atags_vaddr = FDT_VIRT_BASE(__atags_pointer);
1109
1110	setup_processor();
1111	if (atags_vaddr) {
1112		mdesc = setup_machine_fdt(atags_vaddr);
1113		if (mdesc)
1114			memblock_reserve(__atags_pointer,
1115					 fdt_totalsize(atags_vaddr));
1116	}
1117	if (!mdesc)
1118		mdesc = setup_machine_tags(atags_vaddr, __machine_arch_type);
1119	if (!mdesc) {
1120		early_print("\nError: invalid dtb and unrecognized/unsupported machine ID\n");
1121		early_print("  r1=0x%08x, r2=0x%08x\n", __machine_arch_type,
1122			    __atags_pointer);
1123		if (__atags_pointer)
1124			early_print("  r2[]=%*ph\n", 16, atags_vaddr);
 
1125		dump_machine_table();
1126	}
1127
1128	machine_desc = mdesc;
1129	machine_name = mdesc->name;
1130	dump_stack_set_arch_desc("%s", mdesc->name);
1131
1132	if (mdesc->reboot_mode != REBOOT_HARD)
1133		reboot_mode = mdesc->reboot_mode;
1134
1135	setup_initial_init_mm(_text, _etext, _edata, _end);
 
 
 
1136
1137	/* populate cmd_line too for later use, preserving boot_command_line */
1138	strscpy(cmd_line, boot_command_line, COMMAND_LINE_SIZE);
1139	*cmdline_p = cmd_line;
1140
1141	early_fixmap_init();
1142	early_ioremap_init();
1143
1144	parse_early_param();
1145
1146#ifdef CONFIG_MMU
1147	early_mm_init(mdesc);
1148#endif
1149	setup_dma_zone(mdesc);
1150	xen_early_init();
1151	arm_efi_init();
1152	/*
1153	 * Make sure the calculation for lowmem/highmem is set appropriately
1154	 * before reserving/allocating any memory
1155	 */
1156	adjust_lowmem_bounds();
1157	arm_memblock_init(mdesc);
1158	/* Memory may have been removed so recalculate the bounds. */
1159	adjust_lowmem_bounds();
1160
1161	early_ioremap_reset();
1162
1163	paging_init(mdesc);
1164	kasan_init();
1165	request_standard_resources(mdesc);
1166
1167	if (mdesc->restart) {
1168		__arm_pm_restart = mdesc->restart;
1169		register_restart_handler(&arm_restart_nb);
1170	}
1171
1172	unflatten_device_tree();
1173
1174	arm_dt_init_cpu_maps();
1175	psci_dt_init();
1176#ifdef CONFIG_SMP
1177	if (is_smp()) {
1178		if (!mdesc->smp_init || !mdesc->smp_init()) {
1179			if (psci_smp_available())
1180				smp_set_ops(&psci_smp_ops);
1181			else if (mdesc->smp)
1182				smp_set_ops(mdesc->smp);
1183		}
1184		smp_init_cpus();
1185		smp_build_mpidr_hash();
1186	}
1187#endif
1188
1189	if (!is_smp())
1190		hyp_mode_check();
1191
1192	reserve_crashkernel();
1193
 
 
 
 
1194#ifdef CONFIG_VT
1195#if defined(CONFIG_VGA_CONSOLE)
1196	vgacon_register_screen(&vgacon_screen_info);
1197#endif
1198#endif
1199
1200	if (mdesc->init_early)
1201		mdesc->init_early();
1202}
1203
1204bool arch_cpu_is_hotpluggable(int num)
 
1205{
1206	return platform_can_hotplug_cpu(num);
 
 
 
 
 
 
 
 
1207}
 
1208
1209#ifdef CONFIG_HAVE_PROC_CPU
1210static int __init proc_cpu_init(void)
1211{
1212	struct proc_dir_entry *res;
1213
1214	res = proc_mkdir("cpu", NULL);
1215	if (!res)
1216		return -ENOMEM;
1217	return 0;
1218}
1219fs_initcall(proc_cpu_init);
1220#endif
1221
1222static const char *hwcap_str[] = {
1223	"swp",
1224	"half",
1225	"thumb",
1226	"26bit",
1227	"fastmult",
1228	"fpa",
1229	"vfp",
1230	"edsp",
1231	"java",
1232	"iwmmxt",
1233	"crunch",
1234	"thumbee",
1235	"neon",
1236	"vfpv3",
1237	"vfpv3d16",
1238	"tls",
1239	"vfpv4",
1240	"idiva",
1241	"idivt",
1242	"vfpd32",
1243	"lpae",
1244	"evtstrm",
1245	"fphp",
1246	"asimdhp",
1247	"asimddp",
1248	"asimdfhm",
1249	"asimdbf16",
1250	"i8mm",
1251	NULL
1252};
1253
1254static const char *hwcap2_str[] = {
1255	"aes",
1256	"pmull",
1257	"sha1",
1258	"sha2",
1259	"crc32",
1260	"sb",
1261	"ssbs",
1262	NULL
1263};
1264
1265static int c_show(struct seq_file *m, void *v)
1266{
1267	int i, j;
1268	u32 cpuid;
1269
1270	for_each_online_cpu(i) {
1271		/*
1272		 * glibc reads /proc/cpuinfo to determine the number of
1273		 * online processors, looking for lines beginning with
1274		 * "processor".  Give glibc what it expects.
1275		 */
1276		seq_printf(m, "processor\t: %d\n", i);
1277		cpuid = is_smp() ? per_cpu(cpu_data, i).cpuid : read_cpuid_id();
1278		seq_printf(m, "model name\t: %s rev %d (%s)\n",
1279			   cpu_name, cpuid & 15, elf_platform);
1280
1281#if defined(CONFIG_SMP)
1282		seq_printf(m, "BogoMIPS\t: %lu.%02lu\n",
1283			   per_cpu(cpu_data, i).loops_per_jiffy / (500000UL/HZ),
1284			   (per_cpu(cpu_data, i).loops_per_jiffy / (5000UL/HZ)) % 100);
1285#else
1286		seq_printf(m, "BogoMIPS\t: %lu.%02lu\n",
1287			   loops_per_jiffy / (500000/HZ),
1288			   (loops_per_jiffy / (5000/HZ)) % 100);
1289#endif
1290		/* dump out the processor features */
1291		seq_puts(m, "Features\t: ");
1292
1293		for (j = 0; hwcap_str[j]; j++)
1294			if (elf_hwcap & (1 << j))
1295				seq_printf(m, "%s ", hwcap_str[j]);
1296
1297		for (j = 0; hwcap2_str[j]; j++)
1298			if (elf_hwcap2 & (1 << j))
1299				seq_printf(m, "%s ", hwcap2_str[j]);
1300
1301		seq_printf(m, "\nCPU implementer\t: 0x%02x\n", cpuid >> 24);
1302		seq_printf(m, "CPU architecture: %s\n",
1303			   proc_arch[cpu_architecture()]);
1304
1305		if ((cpuid & 0x0008f000) == 0x00000000) {
1306			/* pre-ARM7 */
1307			seq_printf(m, "CPU part\t: %07x\n", cpuid >> 4);
1308		} else {
1309			if ((cpuid & 0x0008f000) == 0x00007000) {
1310				/* ARM7 */
1311				seq_printf(m, "CPU variant\t: 0x%02x\n",
1312					   (cpuid >> 16) & 127);
1313			} else {
1314				/* post-ARM7 */
1315				seq_printf(m, "CPU variant\t: 0x%x\n",
1316					   (cpuid >> 20) & 15);
1317			}
1318			seq_printf(m, "CPU part\t: 0x%03x\n",
1319				   (cpuid >> 4) & 0xfff);
1320		}
1321		seq_printf(m, "CPU revision\t: %d\n\n", cpuid & 15);
1322	}
1323
1324	seq_printf(m, "Hardware\t: %s\n", machine_name);
1325	seq_printf(m, "Revision\t: %04x\n", system_rev);
1326	seq_printf(m, "Serial\t\t: %s\n", system_serial);
1327
1328	return 0;
1329}
1330
1331static void *c_start(struct seq_file *m, loff_t *pos)
1332{
1333	return *pos < 1 ? (void *)1 : NULL;
1334}
1335
1336static void *c_next(struct seq_file *m, void *v, loff_t *pos)
1337{
1338	++*pos;
1339	return NULL;
1340}
1341
1342static void c_stop(struct seq_file *m, void *v)
1343{
1344}
1345
1346const struct seq_operations cpuinfo_op = {
1347	.start	= c_start,
1348	.next	= c_next,
1349	.stop	= c_stop,
1350	.show	= c_show
1351};
v5.9
   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/of_fdt.h>
  22#include <linux/cpu.h>
  23#include <linux/interrupt.h>
  24#include <linux/smp.h>
  25#include <linux/proc_fs.h>
  26#include <linux/memblock.h>
  27#include <linux/bug.h>
  28#include <linux/compiler.h>
  29#include <linux/sort.h>
  30#include <linux/psci.h>
  31
  32#include <asm/unified.h>
  33#include <asm/cp15.h>
  34#include <asm/cpu.h>
  35#include <asm/cputype.h>
  36#include <asm/efi.h>
  37#include <asm/elf.h>
  38#include <asm/early_ioremap.h>
  39#include <asm/fixmap.h>
  40#include <asm/procinfo.h>
  41#include <asm/psci.h>
  42#include <asm/sections.h>
  43#include <asm/setup.h>
  44#include <asm/smp_plat.h>
  45#include <asm/mach-types.h>
  46#include <asm/cacheflush.h>
  47#include <asm/cachetype.h>
  48#include <asm/tlbflush.h>
  49#include <asm/xen/hypervisor.h>
  50
  51#include <asm/prom.h>
  52#include <asm/mach/arch.h>
  53#include <asm/mach/irq.h>
  54#include <asm/mach/time.h>
  55#include <asm/system_info.h>
  56#include <asm/system_misc.h>
  57#include <asm/traps.h>
  58#include <asm/unwind.h>
  59#include <asm/memblock.h>
  60#include <asm/virt.h>
 
  61
  62#include "atags.h"
  63
  64
  65#if defined(CONFIG_FPE_NWFPE) || defined(CONFIG_FPE_FASTFPE)
  66char fpe_type[8];
  67
  68static int __init fpe_setup(char *line)
  69{
  70	memcpy(fpe_type, line, 8);
  71	return 1;
  72}
  73
  74__setup("fpe=", fpe_setup);
  75#endif
  76
  77extern void init_default_cache_policy(unsigned long);
  78extern void paging_init(const struct machine_desc *desc);
  79extern void early_mm_init(const struct machine_desc *);
  80extern void adjust_lowmem_bounds(void);
  81extern enum reboot_mode reboot_mode;
  82extern void setup_dma_zone(const struct machine_desc *desc);
  83
  84unsigned int processor_id;
  85EXPORT_SYMBOL(processor_id);
  86unsigned int __machine_arch_type __read_mostly;
  87EXPORT_SYMBOL(__machine_arch_type);
  88unsigned int cacheid __read_mostly;
  89EXPORT_SYMBOL(cacheid);
  90
  91unsigned int __atags_pointer __initdata;
  92
  93unsigned int system_rev;
  94EXPORT_SYMBOL(system_rev);
  95
  96const char *system_serial;
  97EXPORT_SYMBOL(system_serial);
  98
  99unsigned int system_serial_low;
 100EXPORT_SYMBOL(system_serial_low);
 101
 102unsigned int system_serial_high;
 103EXPORT_SYMBOL(system_serial_high);
 104
 105unsigned int elf_hwcap __read_mostly;
 106EXPORT_SYMBOL(elf_hwcap);
 107
 108unsigned int elf_hwcap2 __read_mostly;
 109EXPORT_SYMBOL(elf_hwcap2);
 110
 111
 112#ifdef MULTI_CPU
 113struct processor processor __ro_after_init;
 114#if defined(CONFIG_BIG_LITTLE) && defined(CONFIG_HARDEN_BRANCH_PREDICTOR)
 115struct processor *cpu_vtable[NR_CPUS] = {
 116	[0] = &processor,
 117};
 118#endif
 119#endif
 120#ifdef MULTI_TLB
 121struct cpu_tlb_fns cpu_tlb __ro_after_init;
 122#endif
 123#ifdef MULTI_USER
 124struct cpu_user_fns cpu_user __ro_after_init;
 125#endif
 126#ifdef MULTI_CACHE
 127struct cpu_cache_fns cpu_cache __ro_after_init;
 128#endif
 129#ifdef CONFIG_OUTER_CACHE
 130struct outer_cache_fns outer_cache __ro_after_init;
 131EXPORT_SYMBOL(outer_cache);
 132#endif
 133
 134/*
 135 * Cached cpu_architecture() result for use by assembler code.
 136 * C code should use the cpu_architecture() function instead of accessing this
 137 * variable directly.
 138 */
 139int __cpu_architecture __read_mostly = CPU_ARCH_UNKNOWN;
 140
 141struct stack {
 142	u32 irq[3];
 143	u32 abt[3];
 144	u32 und[3];
 145	u32 fiq[3];
 146} ____cacheline_aligned;
 147
 148#ifndef CONFIG_CPU_V7M
 149static struct stack stacks[NR_CPUS];
 150#endif
 151
 152char elf_platform[ELF_PLATFORM_SIZE];
 153EXPORT_SYMBOL(elf_platform);
 154
 155static const char *cpu_name;
 156static const char *machine_name;
 157static char __initdata cmd_line[COMMAND_LINE_SIZE];
 158const struct machine_desc *machine_desc __initdata;
 159
 160static union { char c[4]; unsigned long l; } endian_test __initdata = { { 'l', '?', '?', 'b' } };
 161#define ENDIANNESS ((char)endian_test.l)
 162
 163DEFINE_PER_CPU(struct cpuinfo_arm, cpu_data);
 164
 165/*
 166 * Standard memory resources
 167 */
 168static struct resource mem_res[] = {
 169	{
 170		.name = "Video RAM",
 171		.start = 0,
 172		.end = 0,
 173		.flags = IORESOURCE_MEM
 174	},
 175	{
 176		.name = "Kernel code",
 177		.start = 0,
 178		.end = 0,
 179		.flags = IORESOURCE_SYSTEM_RAM
 180	},
 181	{
 182		.name = "Kernel data",
 183		.start = 0,
 184		.end = 0,
 185		.flags = IORESOURCE_SYSTEM_RAM
 186	}
 187};
 188
 189#define video_ram   mem_res[0]
 190#define kernel_code mem_res[1]
 191#define kernel_data mem_res[2]
 192
 193static struct resource io_res[] = {
 194	{
 195		.name = "reserved",
 196		.start = 0x3bc,
 197		.end = 0x3be,
 198		.flags = IORESOURCE_IO | IORESOURCE_BUSY
 199	},
 200	{
 201		.name = "reserved",
 202		.start = 0x378,
 203		.end = 0x37f,
 204		.flags = IORESOURCE_IO | IORESOURCE_BUSY
 205	},
 206	{
 207		.name = "reserved",
 208		.start = 0x278,
 209		.end = 0x27f,
 210		.flags = IORESOURCE_IO | IORESOURCE_BUSY
 211	}
 212};
 213
 214#define lp0 io_res[0]
 215#define lp1 io_res[1]
 216#define lp2 io_res[2]
 217
 218static const char *proc_arch[] = {
 219	"undefined/unknown",
 220	"3",
 221	"4",
 222	"4T",
 223	"5",
 224	"5T",
 225	"5TE",
 226	"5TEJ",
 227	"6TEJ",
 228	"7",
 229	"7M",
 230	"?(12)",
 231	"?(13)",
 232	"?(14)",
 233	"?(15)",
 234	"?(16)",
 235	"?(17)",
 236};
 237
 238#ifdef CONFIG_CPU_V7M
 239static int __get_cpu_architecture(void)
 240{
 241	return CPU_ARCH_ARMv7M;
 242}
 243#else
 244static int __get_cpu_architecture(void)
 245{
 246	int cpu_arch;
 247
 248	if ((read_cpuid_id() & 0x0008f000) == 0) {
 249		cpu_arch = CPU_ARCH_UNKNOWN;
 250	} else if ((read_cpuid_id() & 0x0008f000) == 0x00007000) {
 251		cpu_arch = (read_cpuid_id() & (1 << 23)) ? CPU_ARCH_ARMv4T : CPU_ARCH_ARMv3;
 252	} else if ((read_cpuid_id() & 0x00080000) == 0x00000000) {
 253		cpu_arch = (read_cpuid_id() >> 16) & 7;
 254		if (cpu_arch)
 255			cpu_arch += CPU_ARCH_ARMv3;
 256	} else if ((read_cpuid_id() & 0x000f0000) == 0x000f0000) {
 257		/* Revised CPUID format. Read the Memory Model Feature
 258		 * Register 0 and check for VMSAv7 or PMSAv7 */
 259		unsigned int mmfr0 = read_cpuid_ext(CPUID_EXT_MMFR0);
 260		if ((mmfr0 & 0x0000000f) >= 0x00000003 ||
 261		    (mmfr0 & 0x000000f0) >= 0x00000030)
 262			cpu_arch = CPU_ARCH_ARMv7;
 263		else if ((mmfr0 & 0x0000000f) == 0x00000002 ||
 264			 (mmfr0 & 0x000000f0) == 0x00000020)
 265			cpu_arch = CPU_ARCH_ARMv6;
 266		else
 267			cpu_arch = CPU_ARCH_UNKNOWN;
 268	} else
 269		cpu_arch = CPU_ARCH_UNKNOWN;
 270
 271	return cpu_arch;
 272}
 273#endif
 274
 275int __pure cpu_architecture(void)
 276{
 277	BUG_ON(__cpu_architecture == CPU_ARCH_UNKNOWN);
 278
 279	return __cpu_architecture;
 280}
 281
 282static int cpu_has_aliasing_icache(unsigned int arch)
 283{
 284	int aliasing_icache;
 285	unsigned int id_reg, num_sets, line_size;
 286
 287	/* PIPT caches never alias. */
 288	if (icache_is_pipt())
 289		return 0;
 290
 291	/* arch specifies the register format */
 292	switch (arch) {
 293	case CPU_ARCH_ARMv7:
 294		set_csselr(CSSELR_ICACHE | CSSELR_L1);
 295		isb();
 296		id_reg = read_ccsidr();
 297		line_size = 4 << ((id_reg & 0x7) + 2);
 298		num_sets = ((id_reg >> 13) & 0x7fff) + 1;
 299		aliasing_icache = (line_size * num_sets) > PAGE_SIZE;
 300		break;
 301	case CPU_ARCH_ARMv6:
 302		aliasing_icache = read_cpuid_cachetype() & (1 << 11);
 303		break;
 304	default:
 305		/* I-cache aliases will be handled by D-cache aliasing code */
 306		aliasing_icache = 0;
 307	}
 308
 309	return aliasing_icache;
 310}
 311
 312static void __init cacheid_init(void)
 313{
 314	unsigned int arch = cpu_architecture();
 315
 316	if (arch >= CPU_ARCH_ARMv6) {
 317		unsigned int cachetype = read_cpuid_cachetype();
 318
 319		if ((arch == CPU_ARCH_ARMv7M) && !(cachetype & 0xf000f)) {
 320			cacheid = 0;
 321		} else if ((cachetype & (7 << 29)) == 4 << 29) {
 322			/* ARMv7 register format */
 323			arch = CPU_ARCH_ARMv7;
 324			cacheid = CACHEID_VIPT_NONALIASING;
 325			switch (cachetype & (3 << 14)) {
 326			case (1 << 14):
 327				cacheid |= CACHEID_ASID_TAGGED;
 328				break;
 329			case (3 << 14):
 330				cacheid |= CACHEID_PIPT;
 331				break;
 332			}
 333		} else {
 334			arch = CPU_ARCH_ARMv6;
 335			if (cachetype & (1 << 23))
 336				cacheid = CACHEID_VIPT_ALIASING;
 337			else
 338				cacheid = CACHEID_VIPT_NONALIASING;
 339		}
 340		if (cpu_has_aliasing_icache(arch))
 341			cacheid |= CACHEID_VIPT_I_ALIASING;
 342	} else {
 343		cacheid = CACHEID_VIVT;
 344	}
 345
 346	pr_info("CPU: %s data cache, %s instruction cache\n",
 347		cache_is_vivt() ? "VIVT" :
 348		cache_is_vipt_aliasing() ? "VIPT aliasing" :
 349		cache_is_vipt_nonaliasing() ? "PIPT / VIPT nonaliasing" : "unknown",
 350		cache_is_vivt() ? "VIVT" :
 351		icache_is_vivt_asid_tagged() ? "VIVT ASID tagged" :
 352		icache_is_vipt_aliasing() ? "VIPT aliasing" :
 353		icache_is_pipt() ? "PIPT" :
 354		cache_is_vipt_nonaliasing() ? "VIPT nonaliasing" : "unknown");
 355}
 356
 357/*
 358 * These functions re-use the assembly code in head.S, which
 359 * already provide the required functionality.
 360 */
 361extern struct proc_info_list *lookup_processor_type(unsigned int);
 362
 363void __init early_print(const char *str, ...)
 364{
 365	extern void printascii(const char *);
 366	char buf[256];
 367	va_list ap;
 368
 369	va_start(ap, str);
 370	vsnprintf(buf, sizeof(buf), str, ap);
 371	va_end(ap);
 372
 373#ifdef CONFIG_DEBUG_LL
 374	printascii(buf);
 375#endif
 376	printk("%s", buf);
 377}
 378
 379#ifdef CONFIG_ARM_PATCH_IDIV
 380
 381static inline u32 __attribute_const__ sdiv_instruction(void)
 382{
 383	if (IS_ENABLED(CONFIG_THUMB2_KERNEL)) {
 384		/* "sdiv r0, r0, r1" */
 385		u32 insn = __opcode_thumb32_compose(0xfb90, 0xf0f1);
 386		return __opcode_to_mem_thumb32(insn);
 387	}
 388
 389	/* "sdiv r0, r0, r1" */
 390	return __opcode_to_mem_arm(0xe710f110);
 391}
 392
 393static inline u32 __attribute_const__ udiv_instruction(void)
 394{
 395	if (IS_ENABLED(CONFIG_THUMB2_KERNEL)) {
 396		/* "udiv r0, r0, r1" */
 397		u32 insn = __opcode_thumb32_compose(0xfbb0, 0xf0f1);
 398		return __opcode_to_mem_thumb32(insn);
 399	}
 400
 401	/* "udiv r0, r0, r1" */
 402	return __opcode_to_mem_arm(0xe730f110);
 403}
 404
 405static inline u32 __attribute_const__ bx_lr_instruction(void)
 406{
 407	if (IS_ENABLED(CONFIG_THUMB2_KERNEL)) {
 408		/* "bx lr; nop" */
 409		u32 insn = __opcode_thumb32_compose(0x4770, 0x46c0);
 410		return __opcode_to_mem_thumb32(insn);
 411	}
 412
 413	/* "bx lr" */
 414	return __opcode_to_mem_arm(0xe12fff1e);
 415}
 416
 417static void __init patch_aeabi_idiv(void)
 418{
 419	extern void __aeabi_uidiv(void);
 420	extern void __aeabi_idiv(void);
 421	uintptr_t fn_addr;
 422	unsigned int mask;
 423
 424	mask = IS_ENABLED(CONFIG_THUMB2_KERNEL) ? HWCAP_IDIVT : HWCAP_IDIVA;
 425	if (!(elf_hwcap & mask))
 426		return;
 427
 428	pr_info("CPU: div instructions available: patching division code\n");
 429
 430	fn_addr = ((uintptr_t)&__aeabi_uidiv) & ~1;
 431	asm ("" : "+g" (fn_addr));
 432	((u32 *)fn_addr)[0] = udiv_instruction();
 433	((u32 *)fn_addr)[1] = bx_lr_instruction();
 434	flush_icache_range(fn_addr, fn_addr + 8);
 435
 436	fn_addr = ((uintptr_t)&__aeabi_idiv) & ~1;
 437	asm ("" : "+g" (fn_addr));
 438	((u32 *)fn_addr)[0] = sdiv_instruction();
 439	((u32 *)fn_addr)[1] = bx_lr_instruction();
 440	flush_icache_range(fn_addr, fn_addr + 8);
 441}
 442
 443#else
 444static inline void patch_aeabi_idiv(void) { }
 445#endif
 446
 447static void __init cpuid_init_hwcaps(void)
 448{
 449	int block;
 450	u32 isar5;
 
 
 451
 452	if (cpu_architecture() < CPU_ARCH_ARMv7)
 453		return;
 454
 455	block = cpuid_feature_extract(CPUID_EXT_ISAR0, 24);
 456	if (block >= 2)
 457		elf_hwcap |= HWCAP_IDIVA;
 458	if (block >= 1)
 459		elf_hwcap |= HWCAP_IDIVT;
 460
 461	/* LPAE implies atomic ldrd/strd instructions */
 462	block = cpuid_feature_extract(CPUID_EXT_MMFR0, 0);
 463	if (block >= 5)
 464		elf_hwcap |= HWCAP_LPAE;
 465
 466	/* check for supported v8 Crypto instructions */
 467	isar5 = read_cpuid_ext(CPUID_EXT_ISAR5);
 468
 469	block = cpuid_feature_extract_field(isar5, 4);
 470	if (block >= 2)
 471		elf_hwcap2 |= HWCAP2_PMULL;
 472	if (block >= 1)
 473		elf_hwcap2 |= HWCAP2_AES;
 474
 475	block = cpuid_feature_extract_field(isar5, 8);
 476	if (block >= 1)
 477		elf_hwcap2 |= HWCAP2_SHA1;
 478
 479	block = cpuid_feature_extract_field(isar5, 12);
 480	if (block >= 1)
 481		elf_hwcap2 |= HWCAP2_SHA2;
 482
 483	block = cpuid_feature_extract_field(isar5, 16);
 484	if (block >= 1)
 485		elf_hwcap2 |= HWCAP2_CRC32;
 
 
 
 
 
 
 
 
 
 
 
 
 486}
 487
 488static void __init elf_hwcap_fixup(void)
 489{
 490	unsigned id = read_cpuid_id();
 491
 492	/*
 493	 * HWCAP_TLS is available only on 1136 r1p0 and later,
 494	 * see also kuser_get_tls_init.
 495	 */
 496	if (read_cpuid_part() == ARM_CPU_PART_ARM1136 &&
 497	    ((id >> 20) & 3) == 0) {
 498		elf_hwcap &= ~HWCAP_TLS;
 499		return;
 500	}
 501
 502	/* Verify if CPUID scheme is implemented */
 503	if ((id & 0x000f0000) != 0x000f0000)
 504		return;
 505
 506	/*
 507	 * If the CPU supports LDREX/STREX and LDREXB/STREXB,
 508	 * avoid advertising SWP; it may not be atomic with
 509	 * multiprocessing cores.
 510	 */
 511	if (cpuid_feature_extract(CPUID_EXT_ISAR3, 12) > 1 ||
 512	    (cpuid_feature_extract(CPUID_EXT_ISAR3, 12) == 1 &&
 513	     cpuid_feature_extract(CPUID_EXT_ISAR4, 20) >= 3))
 514		elf_hwcap &= ~HWCAP_SWP;
 515}
 516
 517/*
 518 * cpu_init - initialise one CPU.
 519 *
 520 * cpu_init sets up the per-CPU stacks.
 521 */
 522void notrace cpu_init(void)
 523{
 524#ifndef CONFIG_CPU_V7M
 525	unsigned int cpu = smp_processor_id();
 526	struct stack *stk = &stacks[cpu];
 527
 528	if (cpu >= NR_CPUS) {
 529		pr_crit("CPU%u: bad primary CPU number\n", cpu);
 530		BUG();
 531	}
 532
 533	/*
 534	 * This only works on resume and secondary cores. For booting on the
 535	 * boot cpu, smp_prepare_boot_cpu is called after percpu area setup.
 536	 */
 537	set_my_cpu_offset(per_cpu_offset(cpu));
 538
 539	cpu_proc_init();
 540
 541	/*
 542	 * Define the placement constraint for the inline asm directive below.
 543	 * In Thumb-2, msr with an immediate value is not allowed.
 544	 */
 545#ifdef CONFIG_THUMB2_KERNEL
 546#define PLC	"r"
 
 547#else
 548#define PLC	"I"
 
 549#endif
 550
 551	/*
 552	 * setup stacks for re-entrant exception handlers
 553	 */
 554	__asm__ (
 555	"msr	cpsr_c, %1\n\t"
 556	"add	r14, %0, %2\n\t"
 557	"mov	sp, r14\n\t"
 558	"msr	cpsr_c, %3\n\t"
 559	"add	r14, %0, %4\n\t"
 560	"mov	sp, r14\n\t"
 561	"msr	cpsr_c, %5\n\t"
 562	"add	r14, %0, %6\n\t"
 563	"mov	sp, r14\n\t"
 564	"msr	cpsr_c, %7\n\t"
 565	"add	r14, %0, %8\n\t"
 566	"mov	sp, r14\n\t"
 567	"msr	cpsr_c, %9"
 568	    :
 569	    : "r" (stk),
 570	      PLC (PSR_F_BIT | PSR_I_BIT | IRQ_MODE),
 571	      "I" (offsetof(struct stack, irq[0])),
 572	      PLC (PSR_F_BIT | PSR_I_BIT | ABT_MODE),
 573	      "I" (offsetof(struct stack, abt[0])),
 574	      PLC (PSR_F_BIT | PSR_I_BIT | UND_MODE),
 575	      "I" (offsetof(struct stack, und[0])),
 576	      PLC (PSR_F_BIT | PSR_I_BIT | FIQ_MODE),
 577	      "I" (offsetof(struct stack, fiq[0])),
 578	      PLC (PSR_F_BIT | PSR_I_BIT | SVC_MODE)
 579	    : "r14");
 580#endif
 581}
 582
 583u32 __cpu_logical_map[NR_CPUS] = { [0 ... NR_CPUS-1] = MPIDR_INVALID };
 584
 585void __init smp_setup_processor_id(void)
 586{
 587	int i;
 588	u32 mpidr = is_smp() ? read_cpuid_mpidr() & MPIDR_HWID_BITMASK : 0;
 589	u32 cpu = MPIDR_AFFINITY_LEVEL(mpidr, 0);
 590
 591	cpu_logical_map(0) = cpu;
 592	for (i = 1; i < nr_cpu_ids; ++i)
 593		cpu_logical_map(i) = i == cpu ? 0 : i;
 594
 595	/*
 596	 * clear __my_cpu_offset on boot CPU to avoid hang caused by
 597	 * using percpu variable early, for example, lockdep will
 598	 * access percpu variable inside lock_release
 599	 */
 600	set_my_cpu_offset(0);
 601
 602	pr_info("Booting Linux on physical CPU 0x%x\n", mpidr);
 603}
 604
 605struct mpidr_hash mpidr_hash;
 606#ifdef CONFIG_SMP
 607/**
 608 * smp_build_mpidr_hash - Pre-compute shifts required at each affinity
 609 *			  level in order to build a linear index from an
 610 *			  MPIDR value. Resulting algorithm is a collision
 611 *			  free hash carried out through shifting and ORing
 612 */
 613static void __init smp_build_mpidr_hash(void)
 614{
 615	u32 i, affinity;
 616	u32 fs[3], bits[3], ls, mask = 0;
 617	/*
 618	 * Pre-scan the list of MPIDRS and filter out bits that do
 619	 * not contribute to affinity levels, ie they never toggle.
 620	 */
 621	for_each_possible_cpu(i)
 622		mask |= (cpu_logical_map(i) ^ cpu_logical_map(0));
 623	pr_debug("mask of set bits 0x%x\n", mask);
 624	/*
 625	 * Find and stash the last and first bit set at all affinity levels to
 626	 * check how many bits are required to represent them.
 627	 */
 628	for (i = 0; i < 3; i++) {
 629		affinity = MPIDR_AFFINITY_LEVEL(mask, i);
 630		/*
 631		 * Find the MSB bit and LSB bits position
 632		 * to determine how many bits are required
 633		 * to express the affinity level.
 634		 */
 635		ls = fls(affinity);
 636		fs[i] = affinity ? ffs(affinity) - 1 : 0;
 637		bits[i] = ls - fs[i];
 638	}
 639	/*
 640	 * An index can be created from the MPIDR by isolating the
 641	 * significant bits at each affinity level and by shifting
 642	 * them in order to compress the 24 bits values space to a
 643	 * compressed set of values. This is equivalent to hashing
 644	 * the MPIDR through shifting and ORing. It is a collision free
 645	 * hash though not minimal since some levels might contain a number
 646	 * of CPUs that is not an exact power of 2 and their bit
 647	 * representation might contain holes, eg MPIDR[7:0] = {0x2, 0x80}.
 648	 */
 649	mpidr_hash.shift_aff[0] = fs[0];
 650	mpidr_hash.shift_aff[1] = MPIDR_LEVEL_BITS + fs[1] - bits[0];
 651	mpidr_hash.shift_aff[2] = 2*MPIDR_LEVEL_BITS + fs[2] -
 652						(bits[1] + bits[0]);
 653	mpidr_hash.mask = mask;
 654	mpidr_hash.bits = bits[2] + bits[1] + bits[0];
 655	pr_debug("MPIDR hash: aff0[%u] aff1[%u] aff2[%u] mask[0x%x] bits[%u]\n",
 656				mpidr_hash.shift_aff[0],
 657				mpidr_hash.shift_aff[1],
 658				mpidr_hash.shift_aff[2],
 659				mpidr_hash.mask,
 660				mpidr_hash.bits);
 661	/*
 662	 * 4x is an arbitrary value used to warn on a hash table much bigger
 663	 * than expected on most systems.
 664	 */
 665	if (mpidr_hash_size() > 4 * num_possible_cpus())
 666		pr_warn("Large number of MPIDR hash buckets detected\n");
 667	sync_cache_w(&mpidr_hash);
 668}
 669#endif
 670
 671/*
 672 * locate processor in the list of supported processor types.  The linker
 673 * builds this table for us from the entries in arch/arm/mm/proc-*.S
 674 */
 675struct proc_info_list *lookup_processor(u32 midr)
 676{
 677	struct proc_info_list *list = lookup_processor_type(midr);
 678
 679	if (!list) {
 680		pr_err("CPU%u: configuration botched (ID %08x), CPU halted\n",
 681		       smp_processor_id(), midr);
 682		while (1)
 683		/* can't use cpu_relax() here as it may require MMU setup */;
 684	}
 685
 686	return list;
 687}
 688
 689static void __init setup_processor(void)
 690{
 691	unsigned int midr = read_cpuid_id();
 692	struct proc_info_list *list = lookup_processor(midr);
 693
 694	cpu_name = list->cpu_name;
 695	__cpu_architecture = __get_cpu_architecture();
 696
 697	init_proc_vtable(list->proc);
 698#ifdef MULTI_TLB
 699	cpu_tlb = *list->tlb;
 700#endif
 701#ifdef MULTI_USER
 702	cpu_user = *list->user;
 703#endif
 704#ifdef MULTI_CACHE
 705	cpu_cache = *list->cache;
 706#endif
 707
 708	pr_info("CPU: %s [%08x] revision %d (ARMv%s), cr=%08lx\n",
 709		list->cpu_name, midr, midr & 15,
 710		proc_arch[cpu_architecture()], get_cr());
 711
 712	snprintf(init_utsname()->machine, __NEW_UTS_LEN + 1, "%s%c",
 713		 list->arch_name, ENDIANNESS);
 714	snprintf(elf_platform, ELF_PLATFORM_SIZE, "%s%c",
 715		 list->elf_name, ENDIANNESS);
 716	elf_hwcap = list->elf_hwcap;
 717
 718	cpuid_init_hwcaps();
 719	patch_aeabi_idiv();
 720
 721#ifndef CONFIG_ARM_THUMB
 722	elf_hwcap &= ~(HWCAP_THUMB | HWCAP_IDIVT);
 723#endif
 724#ifdef CONFIG_MMU
 725	init_default_cache_policy(list->__cpu_mm_mmu_flags);
 726#endif
 727	erratum_a15_798181_init();
 728
 729	elf_hwcap_fixup();
 730
 731	cacheid_init();
 732	cpu_init();
 733}
 734
 735void __init dump_machine_table(void)
 736{
 737	const struct machine_desc *p;
 738
 739	early_print("Available machine support:\n\nID (hex)\tNAME\n");
 740	for_each_machine_desc(p)
 741		early_print("%08x\t%s\n", p->nr, p->name);
 742
 743	early_print("\nPlease check your kernel config and/or bootloader.\n");
 744
 745	while (true)
 746		/* can't use cpu_relax() here as it may require MMU setup */;
 747}
 748
 749int __init arm_add_memory(u64 start, u64 size)
 750{
 751	u64 aligned_start;
 752
 753	/*
 754	 * Ensure that start/size are aligned to a page boundary.
 755	 * Size is rounded down, start is rounded up.
 756	 */
 757	aligned_start = PAGE_ALIGN(start);
 758	if (aligned_start > start + size)
 759		size = 0;
 760	else
 761		size -= aligned_start - start;
 762
 763#ifndef CONFIG_PHYS_ADDR_T_64BIT
 764	if (aligned_start > ULONG_MAX) {
 765		pr_crit("Ignoring memory at 0x%08llx outside 32-bit physical address space\n",
 766			(long long)start);
 767		return -EINVAL;
 768	}
 769
 770	if (aligned_start + size > ULONG_MAX) {
 771		pr_crit("Truncating memory at 0x%08llx to fit in 32-bit physical address space\n",
 772			(long long)start);
 773		/*
 774		 * To ensure bank->start + bank->size is representable in
 775		 * 32 bits, we use ULONG_MAX as the upper limit rather than 4GB.
 776		 * This means we lose a page after masking.
 777		 */
 778		size = ULONG_MAX - aligned_start;
 779	}
 780#endif
 781
 782	if (aligned_start < PHYS_OFFSET) {
 783		if (aligned_start + size <= PHYS_OFFSET) {
 784			pr_info("Ignoring memory below PHYS_OFFSET: 0x%08llx-0x%08llx\n",
 785				aligned_start, aligned_start + size);
 786			return -EINVAL;
 787		}
 788
 789		pr_info("Ignoring memory below PHYS_OFFSET: 0x%08llx-0x%08llx\n",
 790			aligned_start, (u64)PHYS_OFFSET);
 791
 792		size -= PHYS_OFFSET - aligned_start;
 793		aligned_start = PHYS_OFFSET;
 794	}
 795
 796	start = aligned_start;
 797	size = size & ~(phys_addr_t)(PAGE_SIZE - 1);
 798
 799	/*
 800	 * Check whether this memory region has non-zero size or
 801	 * invalid node number.
 802	 */
 803	if (size == 0)
 804		return -EINVAL;
 805
 806	memblock_add(start, size);
 807	return 0;
 808}
 809
 810/*
 811 * Pick out the memory size.  We look for mem=size@start,
 812 * where start and size are "size[KkMm]"
 813 */
 814
 815static int __init early_mem(char *p)
 816{
 817	static int usermem __initdata = 0;
 818	u64 size;
 819	u64 start;
 820	char *endp;
 821
 822	/*
 823	 * If the user specifies memory size, we
 824	 * blow away any automatically generated
 825	 * size.
 826	 */
 827	if (usermem == 0) {
 828		usermem = 1;
 829		memblock_remove(memblock_start_of_DRAM(),
 830			memblock_end_of_DRAM() - memblock_start_of_DRAM());
 831	}
 832
 833	start = PHYS_OFFSET;
 834	size  = memparse(p, &endp);
 835	if (*endp == '@')
 836		start = memparse(endp + 1, NULL);
 837
 838	arm_add_memory(start, size);
 839
 840	return 0;
 841}
 842early_param("mem", early_mem);
 843
 844static void __init request_standard_resources(const struct machine_desc *mdesc)
 845{
 846	struct memblock_region *region;
 847	struct resource *res;
 
 848
 849	kernel_code.start   = virt_to_phys(_text);
 850	kernel_code.end     = virt_to_phys(__init_begin - 1);
 851	kernel_data.start   = virt_to_phys(_sdata);
 852	kernel_data.end     = virt_to_phys(_end - 1);
 853
 854	for_each_memblock(memory, region) {
 855		phys_addr_t start = __pfn_to_phys(memblock_region_memory_base_pfn(region));
 856		phys_addr_t end = __pfn_to_phys(memblock_region_memory_end_pfn(region)) - 1;
 857		unsigned long boot_alias_start;
 858
 859		/*
 
 
 
 
 
 
 
 860		 * Some systems have a special memory alias which is only
 861		 * used for booting.  We need to advertise this region to
 862		 * kexec-tools so they know where bootable RAM is located.
 863		 */
 864		boot_alias_start = phys_to_idmap(start);
 865		if (arm_has_idmap_alias() && boot_alias_start != IDMAP_INVALID_ADDR) {
 866			res = memblock_alloc(sizeof(*res), SMP_CACHE_BYTES);
 867			if (!res)
 868				panic("%s: Failed to allocate %zu bytes\n",
 869				      __func__, sizeof(*res));
 870			res->name = "System RAM (boot alias)";
 871			res->start = boot_alias_start;
 872			res->end = phys_to_idmap(end);
 873			res->flags = IORESOURCE_MEM | IORESOURCE_BUSY;
 874			request_resource(&iomem_resource, res);
 875		}
 876
 877		res = memblock_alloc(sizeof(*res), SMP_CACHE_BYTES);
 878		if (!res)
 879			panic("%s: Failed to allocate %zu bytes\n", __func__,
 880			      sizeof(*res));
 881		res->name  = "System RAM";
 882		res->start = start;
 883		res->end = end;
 884		res->flags = IORESOURCE_SYSTEM_RAM | IORESOURCE_BUSY;
 885
 886		request_resource(&iomem_resource, res);
 887
 888		if (kernel_code.start >= res->start &&
 889		    kernel_code.end <= res->end)
 890			request_resource(res, &kernel_code);
 891		if (kernel_data.start >= res->start &&
 892		    kernel_data.end <= res->end)
 893			request_resource(res, &kernel_data);
 894	}
 895
 896	if (mdesc->video_start) {
 897		video_ram.start = mdesc->video_start;
 898		video_ram.end   = mdesc->video_end;
 899		request_resource(&iomem_resource, &video_ram);
 900	}
 901
 902	/*
 903	 * Some machines don't have the possibility of ever
 904	 * possessing lp0, lp1 or lp2
 905	 */
 906	if (mdesc->reserve_lp0)
 907		request_resource(&ioport_resource, &lp0);
 908	if (mdesc->reserve_lp1)
 909		request_resource(&ioport_resource, &lp1);
 910	if (mdesc->reserve_lp2)
 911		request_resource(&ioport_resource, &lp2);
 912}
 913
 914#if defined(CONFIG_VGA_CONSOLE) || defined(CONFIG_DUMMY_CONSOLE) || \
 915    defined(CONFIG_EFI)
 916struct screen_info screen_info = {
 917 .orig_video_lines	= 30,
 918 .orig_video_cols	= 80,
 919 .orig_video_mode	= 0,
 920 .orig_video_ega_bx	= 0,
 921 .orig_video_isVGA	= 1,
 922 .orig_video_points	= 8
 923};
 924#endif
 925
 926static int __init customize_machine(void)
 927{
 928	/*
 929	 * customizes platform devices, or adds new ones
 930	 * On DT based machines, we fall back to populating the
 931	 * machine from the device tree, if no callback is provided,
 932	 * otherwise we would always need an init_machine callback.
 933	 */
 934	if (machine_desc->init_machine)
 935		machine_desc->init_machine();
 936
 937	return 0;
 938}
 939arch_initcall(customize_machine);
 940
 941static int __init init_machine_late(void)
 942{
 943	struct device_node *root;
 944	int ret;
 945
 946	if (machine_desc->init_late)
 947		machine_desc->init_late();
 948
 949	root = of_find_node_by_path("/");
 950	if (root) {
 951		ret = of_property_read_string(root, "serial-number",
 952					      &system_serial);
 953		if (ret)
 954			system_serial = NULL;
 955	}
 956
 957	if (!system_serial)
 958		system_serial = kasprintf(GFP_KERNEL, "%08x%08x",
 959					  system_serial_high,
 960					  system_serial_low);
 961
 962	return 0;
 963}
 964late_initcall(init_machine_late);
 965
 966#ifdef CONFIG_KEXEC
 967/*
 968 * The crash region must be aligned to 128MB to avoid
 969 * zImage relocating below the reserved region.
 970 */
 971#define CRASH_ALIGN	(128 << 20)
 972
 973static inline unsigned long long get_total_mem(void)
 974{
 975	unsigned long total;
 976
 977	total = max_low_pfn - min_low_pfn;
 978	return total << PAGE_SHIFT;
 979}
 980
 981/**
 982 * reserve_crashkernel() - reserves memory are for crash kernel
 983 *
 984 * This function reserves memory area given in "crashkernel=" kernel command
 985 * line parameter. The memory reserved is used by a dump capture kernel when
 986 * primary kernel is crashing.
 987 */
 988static void __init reserve_crashkernel(void)
 989{
 990	unsigned long long crash_size, crash_base;
 991	unsigned long long total_mem;
 992	int ret;
 993
 994	total_mem = get_total_mem();
 995	ret = parse_crashkernel(boot_command_line, total_mem,
 996				&crash_size, &crash_base);
 997	if (ret)
 
 
 998		return;
 999
1000	if (crash_base <= 0) {
1001		unsigned long long crash_max = idmap_to_phys((u32)~0);
1002		unsigned long long lowmem_max = __pa(high_memory - 1) + 1;
1003		if (crash_max > lowmem_max)
1004			crash_max = lowmem_max;
1005		crash_base = memblock_find_in_range(CRASH_ALIGN, crash_max,
1006						    crash_size, CRASH_ALIGN);
 
1007		if (!crash_base) {
1008			pr_err("crashkernel reservation failed - No suitable area found.\n");
1009			return;
1010		}
1011	} else {
 
1012		unsigned long long start;
1013
1014		start = memblock_find_in_range(crash_base,
1015					       crash_base + crash_size,
1016					       crash_size, SECTION_SIZE);
1017		if (start != crash_base) {
1018			pr_err("crashkernel reservation failed - memory is in use.\n");
1019			return;
1020		}
1021	}
1022
1023	ret = memblock_reserve(crash_base, crash_size);
1024	if (ret < 0) {
1025		pr_warn("crashkernel reservation failed - memory is in use (0x%lx)\n",
1026			(unsigned long)crash_base);
1027		return;
1028	}
1029
1030	pr_info("Reserving %ldMB of memory at %ldMB for crashkernel (System RAM: %ldMB)\n",
1031		(unsigned long)(crash_size >> 20),
1032		(unsigned long)(crash_base >> 20),
1033		(unsigned long)(total_mem >> 20));
1034
1035	/* The crashk resource must always be located in normal mem */
1036	crashk_res.start = crash_base;
1037	crashk_res.end = crash_base + crash_size - 1;
1038	insert_resource(&iomem_resource, &crashk_res);
1039
1040	if (arm_has_idmap_alias()) {
1041		/*
1042		 * If we have a special RAM alias for use at boot, we
1043		 * need to advertise to kexec tools where the alias is.
1044		 */
1045		static struct resource crashk_boot_res = {
1046			.name = "Crash kernel (boot alias)",
1047			.flags = IORESOURCE_BUSY | IORESOURCE_MEM,
1048		};
1049
1050		crashk_boot_res.start = phys_to_idmap(crash_base);
1051		crashk_boot_res.end = crashk_boot_res.start + crash_size - 1;
1052		insert_resource(&iomem_resource, &crashk_boot_res);
1053	}
1054}
1055#else
1056static inline void reserve_crashkernel(void) {}
1057#endif /* CONFIG_KEXEC */
1058
1059void __init hyp_mode_check(void)
1060{
1061#ifdef CONFIG_ARM_VIRT_EXT
1062	sync_boot_mode();
1063
1064	if (is_hyp_mode_available()) {
1065		pr_info("CPU: All CPU(s) started in HYP mode.\n");
1066		pr_info("CPU: Virtualization extensions available.\n");
1067	} else if (is_hyp_mode_mismatched()) {
1068		pr_warn("CPU: WARNING: CPU(s) started in wrong/inconsistent modes (primary CPU mode 0x%x)\n",
1069			__boot_cpu_mode & MODE_MASK);
1070		pr_warn("CPU: This may indicate a broken bootloader or firmware.\n");
1071	} else
1072		pr_info("CPU: All CPU(s) started in SVC mode.\n");
1073#endif
1074}
1075
 
 
 
 
 
 
 
 
 
 
 
 
 
 
1076void __init setup_arch(char **cmdline_p)
1077{
1078	const struct machine_desc *mdesc;
 
 
 
 
1079
1080	setup_processor();
1081	mdesc = setup_machine_fdt(__atags_pointer);
 
 
 
 
 
1082	if (!mdesc)
1083		mdesc = setup_machine_tags(__atags_pointer, __machine_arch_type);
1084	if (!mdesc) {
1085		early_print("\nError: invalid dtb and unrecognized/unsupported machine ID\n");
1086		early_print("  r1=0x%08x, r2=0x%08x\n", __machine_arch_type,
1087			    __atags_pointer);
1088		if (__atags_pointer)
1089			early_print("  r2[]=%*ph\n", 16,
1090				    phys_to_virt(__atags_pointer));
1091		dump_machine_table();
1092	}
1093
1094	machine_desc = mdesc;
1095	machine_name = mdesc->name;
1096	dump_stack_set_arch_desc("%s", mdesc->name);
1097
1098	if (mdesc->reboot_mode != REBOOT_HARD)
1099		reboot_mode = mdesc->reboot_mode;
1100
1101	init_mm.start_code = (unsigned long) _text;
1102	init_mm.end_code   = (unsigned long) _etext;
1103	init_mm.end_data   = (unsigned long) _edata;
1104	init_mm.brk	   = (unsigned long) _end;
1105
1106	/* populate cmd_line too for later use, preserving boot_command_line */
1107	strlcpy(cmd_line, boot_command_line, COMMAND_LINE_SIZE);
1108	*cmdline_p = cmd_line;
1109
1110	early_fixmap_init();
1111	early_ioremap_init();
1112
1113	parse_early_param();
1114
1115#ifdef CONFIG_MMU
1116	early_mm_init(mdesc);
1117#endif
1118	setup_dma_zone(mdesc);
1119	xen_early_init();
1120	efi_init();
1121	/*
1122	 * Make sure the calculation for lowmem/highmem is set appropriately
1123	 * before reserving/allocating any mmeory
1124	 */
1125	adjust_lowmem_bounds();
1126	arm_memblock_init(mdesc);
1127	/* Memory may have been removed so recalculate the bounds. */
1128	adjust_lowmem_bounds();
1129
1130	early_ioremap_reset();
1131
1132	paging_init(mdesc);
 
1133	request_standard_resources(mdesc);
1134
1135	if (mdesc->restart)
1136		arm_pm_restart = mdesc->restart;
 
 
1137
1138	unflatten_device_tree();
1139
1140	arm_dt_init_cpu_maps();
1141	psci_dt_init();
1142#ifdef CONFIG_SMP
1143	if (is_smp()) {
1144		if (!mdesc->smp_init || !mdesc->smp_init()) {
1145			if (psci_smp_available())
1146				smp_set_ops(&psci_smp_ops);
1147			else if (mdesc->smp)
1148				smp_set_ops(mdesc->smp);
1149		}
1150		smp_init_cpus();
1151		smp_build_mpidr_hash();
1152	}
1153#endif
1154
1155	if (!is_smp())
1156		hyp_mode_check();
1157
1158	reserve_crashkernel();
1159
1160#ifdef CONFIG_GENERIC_IRQ_MULTI_HANDLER
1161	handle_arch_irq = mdesc->handle_irq;
1162#endif
1163
1164#ifdef CONFIG_VT
1165#if defined(CONFIG_VGA_CONSOLE)
1166	conswitchp = &vga_con;
1167#endif
1168#endif
1169
1170	if (mdesc->init_early)
1171		mdesc->init_early();
1172}
1173
1174
1175static int __init topology_init(void)
1176{
1177	int cpu;
1178
1179	for_each_possible_cpu(cpu) {
1180		struct cpuinfo_arm *cpuinfo = &per_cpu(cpu_data, cpu);
1181		cpuinfo->cpu.hotpluggable = platform_can_hotplug_cpu(cpu);
1182		register_cpu(&cpuinfo->cpu, cpu);
1183	}
1184
1185	return 0;
1186}
1187subsys_initcall(topology_init);
1188
1189#ifdef CONFIG_HAVE_PROC_CPU
1190static int __init proc_cpu_init(void)
1191{
1192	struct proc_dir_entry *res;
1193
1194	res = proc_mkdir("cpu", NULL);
1195	if (!res)
1196		return -ENOMEM;
1197	return 0;
1198}
1199fs_initcall(proc_cpu_init);
1200#endif
1201
1202static const char *hwcap_str[] = {
1203	"swp",
1204	"half",
1205	"thumb",
1206	"26bit",
1207	"fastmult",
1208	"fpa",
1209	"vfp",
1210	"edsp",
1211	"java",
1212	"iwmmxt",
1213	"crunch",
1214	"thumbee",
1215	"neon",
1216	"vfpv3",
1217	"vfpv3d16",
1218	"tls",
1219	"vfpv4",
1220	"idiva",
1221	"idivt",
1222	"vfpd32",
1223	"lpae",
1224	"evtstrm",
 
 
 
 
 
 
1225	NULL
1226};
1227
1228static const char *hwcap2_str[] = {
1229	"aes",
1230	"pmull",
1231	"sha1",
1232	"sha2",
1233	"crc32",
 
 
1234	NULL
1235};
1236
1237static int c_show(struct seq_file *m, void *v)
1238{
1239	int i, j;
1240	u32 cpuid;
1241
1242	for_each_online_cpu(i) {
1243		/*
1244		 * glibc reads /proc/cpuinfo to determine the number of
1245		 * online processors, looking for lines beginning with
1246		 * "processor".  Give glibc what it expects.
1247		 */
1248		seq_printf(m, "processor\t: %d\n", i);
1249		cpuid = is_smp() ? per_cpu(cpu_data, i).cpuid : read_cpuid_id();
1250		seq_printf(m, "model name\t: %s rev %d (%s)\n",
1251			   cpu_name, cpuid & 15, elf_platform);
1252
1253#if defined(CONFIG_SMP)
1254		seq_printf(m, "BogoMIPS\t: %lu.%02lu\n",
1255			   per_cpu(cpu_data, i).loops_per_jiffy / (500000UL/HZ),
1256			   (per_cpu(cpu_data, i).loops_per_jiffy / (5000UL/HZ)) % 100);
1257#else
1258		seq_printf(m, "BogoMIPS\t: %lu.%02lu\n",
1259			   loops_per_jiffy / (500000/HZ),
1260			   (loops_per_jiffy / (5000/HZ)) % 100);
1261#endif
1262		/* dump out the processor features */
1263		seq_puts(m, "Features\t: ");
1264
1265		for (j = 0; hwcap_str[j]; j++)
1266			if (elf_hwcap & (1 << j))
1267				seq_printf(m, "%s ", hwcap_str[j]);
1268
1269		for (j = 0; hwcap2_str[j]; j++)
1270			if (elf_hwcap2 & (1 << j))
1271				seq_printf(m, "%s ", hwcap2_str[j]);
1272
1273		seq_printf(m, "\nCPU implementer\t: 0x%02x\n", cpuid >> 24);
1274		seq_printf(m, "CPU architecture: %s\n",
1275			   proc_arch[cpu_architecture()]);
1276
1277		if ((cpuid & 0x0008f000) == 0x00000000) {
1278			/* pre-ARM7 */
1279			seq_printf(m, "CPU part\t: %07x\n", cpuid >> 4);
1280		} else {
1281			if ((cpuid & 0x0008f000) == 0x00007000) {
1282				/* ARM7 */
1283				seq_printf(m, "CPU variant\t: 0x%02x\n",
1284					   (cpuid >> 16) & 127);
1285			} else {
1286				/* post-ARM7 */
1287				seq_printf(m, "CPU variant\t: 0x%x\n",
1288					   (cpuid >> 20) & 15);
1289			}
1290			seq_printf(m, "CPU part\t: 0x%03x\n",
1291				   (cpuid >> 4) & 0xfff);
1292		}
1293		seq_printf(m, "CPU revision\t: %d\n\n", cpuid & 15);
1294	}
1295
1296	seq_printf(m, "Hardware\t: %s\n", machine_name);
1297	seq_printf(m, "Revision\t: %04x\n", system_rev);
1298	seq_printf(m, "Serial\t\t: %s\n", system_serial);
1299
1300	return 0;
1301}
1302
1303static void *c_start(struct seq_file *m, loff_t *pos)
1304{
1305	return *pos < 1 ? (void *)1 : NULL;
1306}
1307
1308static void *c_next(struct seq_file *m, void *v, loff_t *pos)
1309{
1310	++*pos;
1311	return NULL;
1312}
1313
1314static void c_stop(struct seq_file *m, void *v)
1315{
1316}
1317
1318const struct seq_operations cpuinfo_op = {
1319	.start	= c_start,
1320	.next	= c_next,
1321	.stop	= c_stop,
1322	.show	= c_show
1323};