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setup.c

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    setup.c 31.93 KiB
    // SPDX-License-Identifier: GPL-2.0-only
    /*
     *  linux/arch/arm/kernel/setup.c
     *
     *  Copyright (C) 1995-2001 Russell King
     */
    #include <linux/efi.h>
    #include <linux/export.h>
    #include <linux/kernel.h>
    #include <linux/stddef.h>
    #include <linux/ioport.h>
    #include <linux/delay.h>
    #include <linux/utsname.h>
    #include <linux/initrd.h>
    #include <linux/console.h>
    #include <linux/seq_file.h>
    #include <linux/screen_info.h>
    #include <linux/of_platform.h>
    #include <linux/init.h>
    #include <linux/kexec.h>
    #include <linux/libfdt.h>
    #include <linux/of_fdt.h>
    #include <linux/cpu.h>
    #include <linux/interrupt.h>
    #include <linux/smp.h>
    #include <linux/proc_fs.h>
    #include <linux/memblock.h>
    #include <linux/bug.h>
    #include <linux/compiler.h>
    #include <linux/sort.h>
    #include <linux/psci.h>
    
    #include <asm/unified.h>
    #include <asm/cp15.h>
    #include <asm/cpu.h>
    #include <asm/cputype.h>
    #include <asm/efi.h>
    #include <asm/elf.h>
    #include <asm/early_ioremap.h>
    #include <asm/fixmap.h>
    #include <asm/procinfo.h>
    #include <asm/psci.h>
    #include <asm/sections.h>
    #include <asm/setup.h>
    #include <asm/smp_plat.h>
    #include <asm/mach-types.h>
    #include <asm/cacheflush.h>
    #include <asm/cachetype.h>
    #include <asm/tlbflush.h>
    #include <asm/xen/hypervisor.h>
    
    #include <asm/prom.h>
    #include <asm/mach/arch.h>
    #include <asm/mach/irq.h>
    #include <asm/mach/time.h>
    #include <asm/system_info.h>
    #include <asm/system_misc.h>
    #include <asm/traps.h>
    #include <asm/unwind.h>
    #include <asm/memblock.h>
    #include <asm/virt.h>
    
    #include "atags.h"
    
    
    #if defined(CONFIG_FPE_NWFPE) || defined(CONFIG_FPE_FASTFPE)
    char fpe_type[8];
    
    static int __init fpe_setup(char *line)
    {
    	memcpy(fpe_type, line, 8);
    	return 1;
    }
    
    __setup("fpe=", fpe_setup);
    #endif
    
    extern void init_default_cache_policy(unsigned long);
    extern void paging_init(const struct machine_desc *desc);
    extern void early_mm_init(const struct machine_desc *);
    extern void adjust_lowmem_bounds(void);
    extern enum reboot_mode reboot_mode;
    extern void setup_dma_zone(const struct machine_desc *desc);
    
    unsigned int processor_id;
    EXPORT_SYMBOL(processor_id);
    unsigned int __machine_arch_type __read_mostly;
    EXPORT_SYMBOL(__machine_arch_type);
    unsigned int cacheid __read_mostly;
    EXPORT_SYMBOL(cacheid);
    
    unsigned int __atags_pointer __initdata;
    
    unsigned int system_rev;
    EXPORT_SYMBOL(system_rev);
    
    const char *system_serial;
    EXPORT_SYMBOL(system_serial);
    
    unsigned int system_serial_low;
    EXPORT_SYMBOL(system_serial_low);
    
    unsigned int system_serial_high;
    EXPORT_SYMBOL(system_serial_high);
    
    unsigned int elf_hwcap __read_mostly;
    EXPORT_SYMBOL(elf_hwcap);
    
    unsigned int elf_hwcap2 __read_mostly;
    EXPORT_SYMBOL(elf_hwcap2);
    
    
    #ifdef MULTI_CPU
    struct processor processor __ro_after_init;
    #if defined(CONFIG_BIG_LITTLE) && defined(CONFIG_HARDEN_BRANCH_PREDICTOR)
    struct processor *cpu_vtable[NR_CPUS] = {
    	[0] = &processor,
    };
    #endif
    #endif
    #ifdef MULTI_TLB
    struct cpu_tlb_fns cpu_tlb __ro_after_init;
    #endif
    #ifdef MULTI_USER
    struct cpu_user_fns cpu_user __ro_after_init;
    #endif
    #ifdef MULTI_CACHE
    struct cpu_cache_fns cpu_cache __ro_after_init;
    #endif
    #ifdef CONFIG_OUTER_CACHE
    struct outer_cache_fns outer_cache __ro_after_init;
    EXPORT_SYMBOL(outer_cache);
    #endif
    
    /*
     * Cached cpu_architecture() result for use by assembler code.
     * C code should use the cpu_architecture() function instead of accessing this
     * variable directly.
     */
    int __cpu_architecture __read_mostly = CPU_ARCH_UNKNOWN;
    
    struct stack {
    	u32 irq[3];
    	u32 abt[3];
    	u32 und[3];
    	u32 fiq[3];
    } ____cacheline_aligned;
    
    #ifndef CONFIG_CPU_V7M
    static struct stack stacks[NR_CPUS];
    #endif
    
    char elf_platform[ELF_PLATFORM_SIZE];
    EXPORT_SYMBOL(elf_platform);
    
    static const char *cpu_name;
    static const char *machine_name;
    static char __initdata cmd_line[COMMAND_LINE_SIZE];
    const struct machine_desc *machine_desc __initdata;
    
    static union { char c[4]; unsigned long l; } endian_test __initdata = { { 'l', '?', '?', 'b' } };
    #define ENDIANNESS ((char)endian_test.l)
    
    DEFINE_PER_CPU(struct cpuinfo_arm, cpu_data);
    
    /*
     * Standard memory resources
     */
    static struct resource mem_res[] = {
    	{
    		.name = "Video RAM",
    		.start = 0,
    		.end = 0,
    		.flags = IORESOURCE_MEM
    	},
    	{
    		.name = "Kernel code",
    		.start = 0,
    		.end = 0,
    		.flags = IORESOURCE_SYSTEM_RAM
    	},
    	{
    		.name = "Kernel data",
    		.start = 0,
    		.end = 0,
    		.flags = IORESOURCE_SYSTEM_RAM
    	}
    };
    
    #define video_ram   mem_res[0]
    #define kernel_code mem_res[1]
    #define kernel_data mem_res[2]
    
    static struct resource io_res[] = {
    	{
    		.name = "reserved",
    		.start = 0x3bc,
    		.end = 0x3be,
    		.flags = IORESOURCE_IO | IORESOURCE_BUSY
    	},
    	{
    		.name = "reserved",
    		.start = 0x378,
    		.end = 0x37f,
    		.flags = IORESOURCE_IO | IORESOURCE_BUSY
    	},
    	{
    		.name = "reserved",
    		.start = 0x278,
    		.end = 0x27f,
    		.flags = IORESOURCE_IO | IORESOURCE_BUSY
    	}
    };
    
    #define lp0 io_res[0]
    #define lp1 io_res[1]
    #define lp2 io_res[2]
    
    static const char *proc_arch[] = {
    	"undefined/unknown",
    	"3",
    	"4",
    	"4T",
    	"5",
    	"5T",
    	"5TE",
    	"5TEJ",
    	"6TEJ",
    	"7",
    	"7M",
    	"?(12)",
    	"?(13)",
    	"?(14)",
    	"?(15)",
    	"?(16)",
    	"?(17)",
    };
    
    #ifdef CONFIG_CPU_V7M
    static int __get_cpu_architecture(void)
    {
    	return CPU_ARCH_ARMv7M;
    }
    #else
    static int __get_cpu_architecture(void)
    {
    	int cpu_arch;
    
    	if ((read_cpuid_id() & 0x0008f000) == 0) {
    		cpu_arch = CPU_ARCH_UNKNOWN;
    	} else if ((read_cpuid_id() & 0x0008f000) == 0x00007000) {
    		cpu_arch = (read_cpuid_id() & (1 << 23)) ? CPU_ARCH_ARMv4T : CPU_ARCH_ARMv3;
    	} else if ((read_cpuid_id() & 0x00080000) == 0x00000000) {
    		cpu_arch = (read_cpuid_id() >> 16) & 7;
    		if (cpu_arch)
    			cpu_arch += CPU_ARCH_ARMv3;
    	} else if ((read_cpuid_id() & 0x000f0000) == 0x000f0000) {
    		/* Revised CPUID format. Read the Memory Model Feature
    		 * Register 0 and check for VMSAv7 or PMSAv7 */
    		unsigned int mmfr0 = read_cpuid_ext(CPUID_EXT_MMFR0);
    		if ((mmfr0 & 0x0000000f) >= 0x00000003 ||
    		    (mmfr0 & 0x000000f0) >= 0x00000030)
    			cpu_arch = CPU_ARCH_ARMv7;
    		else if ((mmfr0 & 0x0000000f) == 0x00000002 ||
    			 (mmfr0 & 0x000000f0) == 0x00000020)
    			cpu_arch = CPU_ARCH_ARMv6;
    		else
    			cpu_arch = CPU_ARCH_UNKNOWN;
    	} else
    		cpu_arch = CPU_ARCH_UNKNOWN;
    
    	return cpu_arch;
    }
    #endif
    
    int __pure cpu_architecture(void)
    {
    	BUG_ON(__cpu_architecture == CPU_ARCH_UNKNOWN);
    
    	return __cpu_architecture;
    }
    
    static int cpu_has_aliasing_icache(unsigned int arch)
    {
    	int aliasing_icache;
    	unsigned int id_reg, num_sets, line_size;
    
    	/* PIPT caches never alias. */
    	if (icache_is_pipt())
    		return 0;
    
    	/* arch specifies the register format */
    	switch (arch) {
    	case CPU_ARCH_ARMv7:
    		set_csselr(CSSELR_ICACHE | CSSELR_L1);
    		isb();
    		id_reg = read_ccsidr();
    		line_size = 4 << ((id_reg & 0x7) + 2);
    		num_sets = ((id_reg >> 13) & 0x7fff) + 1;
    		aliasing_icache = (line_size * num_sets) > PAGE_SIZE;
    		break;
    	case CPU_ARCH_ARMv6:
    		aliasing_icache = read_cpuid_cachetype() & (1 << 11);
    		break;
    	default:
    		/* I-cache aliases will be handled by D-cache aliasing code */
    		aliasing_icache = 0;
    	}
    
    	return aliasing_icache;
    }
    
    static void __init cacheid_init(void)
    {
    	unsigned int arch = cpu_architecture();
    
    	if (arch >= CPU_ARCH_ARMv6) {
    		unsigned int cachetype = read_cpuid_cachetype();
    
    		if ((arch == CPU_ARCH_ARMv7M) && !(cachetype & 0xf000f)) {
    			cacheid = 0;
    		} else if ((cachetype & (7 << 29)) == 4 << 29) {
    			/* ARMv7 register format */
    			arch = CPU_ARCH_ARMv7;
    			cacheid = CACHEID_VIPT_NONALIASING;
    			switch (cachetype & (3 << 14)) {
    			case (1 << 14):
    				cacheid |= CACHEID_ASID_TAGGED;
    				break;
    			case (3 << 14):
    				cacheid |= CACHEID_PIPT;
    				break;
    			}
    		} else {
    			arch = CPU_ARCH_ARMv6;
    			if (cachetype & (1 << 23))
    				cacheid = CACHEID_VIPT_ALIASING;
    			else
    				cacheid = CACHEID_VIPT_NONALIASING;
    		}
    		if (cpu_has_aliasing_icache(arch))
    			cacheid |= CACHEID_VIPT_I_ALIASING;
    	} else {
    		cacheid = CACHEID_VIVT;
    	}
    
    	pr_info("CPU: %s data cache, %s instruction cache\n",
    		cache_is_vivt() ? "VIVT" :
    		cache_is_vipt_aliasing() ? "VIPT aliasing" :
    		cache_is_vipt_nonaliasing() ? "PIPT / VIPT nonaliasing" : "unknown",
    		cache_is_vivt() ? "VIVT" :
    		icache_is_vivt_asid_tagged() ? "VIVT ASID tagged" :
    		icache_is_vipt_aliasing() ? "VIPT aliasing" :
    		icache_is_pipt() ? "PIPT" :
    		cache_is_vipt_nonaliasing() ? "VIPT nonaliasing" : "unknown");
    }
    
    /*
     * These functions re-use the assembly code in head.S, which
     * already provide the required functionality.
     */
    extern struct proc_info_list *lookup_processor_type(unsigned int);
    
    void __init early_print(const char *str, ...)
    {
    	extern void printascii(const char *);
    	char buf[256];
    	va_list ap;
    
    	va_start(ap, str);
    	vsnprintf(buf, sizeof(buf), str, ap);
    	va_end(ap);
    
    #ifdef CONFIG_DEBUG_LL
    	printascii(buf);
    #endif
    	printk("%s", buf);
    }
    
    #ifdef CONFIG_ARM_PATCH_IDIV
    
    static inline u32 __attribute_const__ sdiv_instruction(void)
    {
    	if (IS_ENABLED(CONFIG_THUMB2_KERNEL)) {
    		/* "sdiv r0, r0, r1" */
    		u32 insn = __opcode_thumb32_compose(0xfb90, 0xf0f1);
    		return __opcode_to_mem_thumb32(insn);
    	}
    
    	/* "sdiv r0, r0, r1" */
    	return __opcode_to_mem_arm(0xe710f110);
    }
    
    static inline u32 __attribute_const__ udiv_instruction(void)
    {
    	if (IS_ENABLED(CONFIG_THUMB2_KERNEL)) {
    		/* "udiv r0, r0, r1" */
    		u32 insn = __opcode_thumb32_compose(0xfbb0, 0xf0f1);
    		return __opcode_to_mem_thumb32(insn);
    	}
    
    	/* "udiv r0, r0, r1" */
    	return __opcode_to_mem_arm(0xe730f110);
    }
    
    static inline u32 __attribute_const__ bx_lr_instruction(void)
    {
    	if (IS_ENABLED(CONFIG_THUMB2_KERNEL)) {
    		/* "bx lr; nop" */
    		u32 insn = __opcode_thumb32_compose(0x4770, 0x46c0);
    		return __opcode_to_mem_thumb32(insn);
    	}
    
    	/* "bx lr" */
    	return __opcode_to_mem_arm(0xe12fff1e);
    }
    
    static void __init patch_aeabi_idiv(void)
    {
    	extern void __aeabi_uidiv(void);
    	extern void __aeabi_idiv(void);
    	uintptr_t fn_addr;
    	unsigned int mask;
    
    	mask = IS_ENABLED(CONFIG_THUMB2_KERNEL) ? HWCAP_IDIVT : HWCAP_IDIVA;
    	if (!(elf_hwcap & mask))
    		return;
    
    	pr_info("CPU: div instructions available: patching division code\n");
    
    	fn_addr = ((uintptr_t)&__aeabi_uidiv) & ~1;
    	asm ("" : "+g" (fn_addr));
    	((u32 *)fn_addr)[0] = udiv_instruction();
    	((u32 *)fn_addr)[1] = bx_lr_instruction();
    	flush_icache_range(fn_addr, fn_addr + 8);
    
    	fn_addr = ((uintptr_t)&__aeabi_idiv) & ~1;
    	asm ("" : "+g" (fn_addr));
    	((u32 *)fn_addr)[0] = sdiv_instruction();
    	((u32 *)fn_addr)[1] = bx_lr_instruction();
    	flush_icache_range(fn_addr, fn_addr + 8);
    }
    
    #else
    static inline void patch_aeabi_idiv(void) { }
    #endif
    
    static void __init cpuid_init_hwcaps(void)
    {
    	int block;
    	u32 isar5;
    
    	if (cpu_architecture() < CPU_ARCH_ARMv7)
    		return;
    
    	block = cpuid_feature_extract(CPUID_EXT_ISAR0, 24);
    	if (block >= 2)
    		elf_hwcap |= HWCAP_IDIVA;
    	if (block >= 1)
    		elf_hwcap |= HWCAP_IDIVT;
    
    	/* LPAE implies atomic ldrd/strd instructions */
    	block = cpuid_feature_extract(CPUID_EXT_MMFR0, 0);
    	if (block >= 5)
    		elf_hwcap |= HWCAP_LPAE;
    
    	/* check for supported v8 Crypto instructions */
    	isar5 = read_cpuid_ext(CPUID_EXT_ISAR5);
    
    	block = cpuid_feature_extract_field(isar5, 4);
    	if (block >= 2)
    		elf_hwcap2 |= HWCAP2_PMULL;
    	if (block >= 1)
    		elf_hwcap2 |= HWCAP2_AES;
    
    	block = cpuid_feature_extract_field(isar5, 8);
    	if (block >= 1)
    		elf_hwcap2 |= HWCAP2_SHA1;
    
    	block = cpuid_feature_extract_field(isar5, 12);
    	if (block >= 1)
    		elf_hwcap2 |= HWCAP2_SHA2;
    
    	block = cpuid_feature_extract_field(isar5, 16);
    	if (block >= 1)
    		elf_hwcap2 |= HWCAP2_CRC32;
    }
    
    static void __init elf_hwcap_fixup(void)
    {
    	unsigned id = read_cpuid_id();
    
    	/*
    	 * HWCAP_TLS is available only on 1136 r1p0 and later,
    	 * see also kuser_get_tls_init.
    	 */
    	if (read_cpuid_part() == ARM_CPU_PART_ARM1136 &&
    	    ((id >> 20) & 3) == 0) {
    		elf_hwcap &= ~HWCAP_TLS;
    		return;
    	}
    
    	/* Verify if CPUID scheme is implemented */
    	if ((id & 0x000f0000) != 0x000f0000)
    		return;
    
    	/*
    	 * If the CPU supports LDREX/STREX and LDREXB/STREXB,
    	 * avoid advertising SWP; it may not be atomic with
    	 * multiprocessing cores.
    	 */
    	if (cpuid_feature_extract(CPUID_EXT_ISAR3, 12) > 1 ||
    	    (cpuid_feature_extract(CPUID_EXT_ISAR3, 12) == 1 &&
    	     cpuid_feature_extract(CPUID_EXT_ISAR4, 20) >= 3))
    		elf_hwcap &= ~HWCAP_SWP;
    }
    
    /*
     * cpu_init - initialise one CPU.
     *
     * cpu_init sets up the per-CPU stacks.
     */
    void notrace cpu_init(void)
    {
    #ifndef CONFIG_CPU_V7M
    	unsigned int cpu = smp_processor_id();
    	struct stack *stk = &stacks[cpu];
    
    	if (cpu >= NR_CPUS) {
    		pr_crit("CPU%u: bad primary CPU number\n", cpu);
    		BUG();
    	}
    
    	/*
    	 * This only works on resume and secondary cores. For booting on the
    	 * boot cpu, smp_prepare_boot_cpu is called after percpu area setup.
    	 */
    	set_my_cpu_offset(per_cpu_offset(cpu));
    
    	cpu_proc_init();
    
    	/*
    	 * Define the placement constraint for the inline asm directive below.
    	 * In Thumb-2, msr with an immediate value is not allowed.
    	 */
    #ifdef CONFIG_THUMB2_KERNEL
    #define PLC_l	"l"
    #define PLC_r	"r"
    #else
    #define PLC_l	"I"
    #define PLC_r	"I"
    #endif
    
    	/*
    	 * setup stacks for re-entrant exception handlers
    	 */
    	__asm__ (
    	"msr	cpsr_c, %1\n\t"
    	"add	r14, %0, %2\n\t"
    	"mov	sp, r14\n\t"
    	"msr	cpsr_c, %3\n\t"
    	"add	r14, %0, %4\n\t"
    	"mov	sp, r14\n\t"
    	"msr	cpsr_c, %5\n\t"
    	"add	r14, %0, %6\n\t"
    	"mov	sp, r14\n\t"
    	"msr	cpsr_c, %7\n\t"
    	"add	r14, %0, %8\n\t"
    	"mov	sp, r14\n\t"
    	"msr	cpsr_c, %9"
    	    :
    	    : "r" (stk),
    	      PLC_r (PSR_F_BIT | PSR_I_BIT | IRQ_MODE),
    	      "I" (offsetof(struct stack, irq[0])),
    	      PLC_r (PSR_F_BIT | PSR_I_BIT | ABT_MODE),
    	      "I" (offsetof(struct stack, abt[0])),
    	      PLC_r (PSR_F_BIT | PSR_I_BIT | UND_MODE),
    	      "I" (offsetof(struct stack, und[0])),
    	      PLC_r (PSR_F_BIT | PSR_I_BIT | FIQ_MODE),
    	      "I" (offsetof(struct stack, fiq[0])),
    	      PLC_l (PSR_F_BIT | PSR_I_BIT | SVC_MODE)
    	    : "r14");
    #endif
    }
    
    u32 __cpu_logical_map[NR_CPUS] = { [0 ... NR_CPUS-1] = MPIDR_INVALID };
    
    void __init smp_setup_processor_id(void)
    {
    	int i;
    	u32 mpidr = is_smp() ? read_cpuid_mpidr() & MPIDR_HWID_BITMASK : 0;
    	u32 cpu = MPIDR_AFFINITY_LEVEL(mpidr, 0);
    
    	cpu_logical_map(0) = cpu;
    	for (i = 1; i < nr_cpu_ids; ++i)
    		cpu_logical_map(i) = i == cpu ? 0 : i;
    
    	/*
    	 * clear __my_cpu_offset on boot CPU to avoid hang caused by
    	 * using percpu variable early, for example, lockdep will
    	 * access percpu variable inside lock_release
    	 */
    	set_my_cpu_offset(0);
    
    	pr_info("Booting Linux on physical CPU 0x%x\n", mpidr);
    }
    
    struct mpidr_hash mpidr_hash;
    #ifdef CONFIG_SMP
    /**
     * smp_build_mpidr_hash - Pre-compute shifts required at each affinity
     *			  level in order to build a linear index from an
     *			  MPIDR value. Resulting algorithm is a collision
     *			  free hash carried out through shifting and ORing
     */
    static void __init smp_build_mpidr_hash(void)
    {
    	u32 i, affinity;
    	u32 fs[3], bits[3], ls, mask = 0;
    	/*
    	 * Pre-scan the list of MPIDRS and filter out bits that do
    	 * not contribute to affinity levels, ie they never toggle.
    	 */
    	for_each_possible_cpu(i)
    		mask |= (cpu_logical_map(i) ^ cpu_logical_map(0));
    	pr_debug("mask of set bits 0x%x\n", mask);
    	/*
    	 * Find and stash the last and first bit set at all affinity levels to
    	 * check how many bits are required to represent them.
    	 */
    	for (i = 0; i < 3; i++) {
    		affinity = MPIDR_AFFINITY_LEVEL(mask, i);
    		/*
    		 * Find the MSB bit and LSB bits position
    		 * to determine how many bits are required
    		 * to express the affinity level.
    		 */
    		ls = fls(affinity);
    		fs[i] = affinity ? ffs(affinity) - 1 : 0;
    		bits[i] = ls - fs[i];
    	}
    	/*
    	 * An index can be created from the MPIDR by isolating the
    	 * significant bits at each affinity level and by shifting
    	 * them in order to compress the 24 bits values space to a
    	 * compressed set of values. This is equivalent to hashing
    	 * the MPIDR through shifting and ORing. It is a collision free
    	 * hash though not minimal since some levels might contain a number
    	 * of CPUs that is not an exact power of 2 and their bit
    	 * representation might contain holes, eg MPIDR[7:0] = {0x2, 0x80}.
    	 */
    	mpidr_hash.shift_aff[0] = fs[0];
    	mpidr_hash.shift_aff[1] = MPIDR_LEVEL_BITS + fs[1] - bits[0];
    	mpidr_hash.shift_aff[2] = 2*MPIDR_LEVEL_BITS + fs[2] -
    						(bits[1] + bits[0]);
    	mpidr_hash.mask = mask;
    	mpidr_hash.bits = bits[2] + bits[1] + bits[0];
    	pr_debug("MPIDR hash: aff0[%u] aff1[%u] aff2[%u] mask[0x%x] bits[%u]\n",
    				mpidr_hash.shift_aff[0],
    				mpidr_hash.shift_aff[1],
    				mpidr_hash.shift_aff[2],
    				mpidr_hash.mask,
    				mpidr_hash.bits);
    	/*
    	 * 4x is an arbitrary value used to warn on a hash table much bigger
    	 * than expected on most systems.
    	 */
    	if (mpidr_hash_size() > 4 * num_possible_cpus())
    		pr_warn("Large number of MPIDR hash buckets detected\n");
    	sync_cache_w(&mpidr_hash);
    }
    #endif
    
    /*
     * locate processor in the list of supported processor types.  The linker
     * builds this table for us from the entries in arch/arm/mm/proc-*.S
     */
    struct proc_info_list *lookup_processor(u32 midr)
    {
    	struct proc_info_list *list = lookup_processor_type(midr);
    
    	if (!list) {
    		pr_err("CPU%u: configuration botched (ID %08x), CPU halted\n",
    		       smp_processor_id(), midr);
    		while (1)
    		/* can't use cpu_relax() here as it may require MMU setup */;
    	}
    
    	return list;
    }
    
    static void __init setup_processor(void)
    {
    	unsigned int midr = read_cpuid_id();
    	struct proc_info_list *list = lookup_processor(midr);
    
    	cpu_name = list->cpu_name;
    	__cpu_architecture = __get_cpu_architecture();
    
    	init_proc_vtable(list->proc);
    #ifdef MULTI_TLB
    	cpu_tlb = *list->tlb;
    #endif
    #ifdef MULTI_USER
    	cpu_user = *list->user;
    #endif
    #ifdef MULTI_CACHE
    	cpu_cache = *list->cache;
    #endif
    
    	pr_info("CPU: %s [%08x] revision %d (ARMv%s), cr=%08lx\n",
    		list->cpu_name, midr, midr & 15,
    		proc_arch[cpu_architecture()], get_cr());
    
    	snprintf(init_utsname()->machine, __NEW_UTS_LEN + 1, "%s%c",
    		 list->arch_name, ENDIANNESS);
    	snprintf(elf_platform, ELF_PLATFORM_SIZE, "%s%c",
    		 list->elf_name, ENDIANNESS);
    	elf_hwcap = list->elf_hwcap;
    
    	cpuid_init_hwcaps();
    	patch_aeabi_idiv();
    
    #ifndef CONFIG_ARM_THUMB
    	elf_hwcap &= ~(HWCAP_THUMB | HWCAP_IDIVT);
    #endif
    #ifdef CONFIG_MMU
    	init_default_cache_policy(list->__cpu_mm_mmu_flags);
    #endif
    	erratum_a15_798181_init();
    
    	elf_hwcap_fixup();
    
    	cacheid_init();
    	cpu_init();
    }
    
    void __init dump_machine_table(void)
    {
    	const struct machine_desc *p;
    
    	early_print("Available machine support:\n\nID (hex)\tNAME\n");
    	for_each_machine_desc(p)
    		early_print("%08x\t%s\n", p->nr, p->name);
    
    	early_print("\nPlease check your kernel config and/or bootloader.\n");
    
    	while (true)
    		/* can't use cpu_relax() here as it may require MMU setup */;
    }
    
    int __init arm_add_memory(u64 start, u64 size)
    {
    	u64 aligned_start;
    
    	/*
    	 * Ensure that start/size are aligned to a page boundary.
    	 * Size is rounded down, start is rounded up.
    	 */
    	aligned_start = PAGE_ALIGN(start);
    	if (aligned_start > start + size)
    		size = 0;
    	else
    		size -= aligned_start - start;
    
    #ifndef CONFIG_PHYS_ADDR_T_64BIT
    	if (aligned_start > ULONG_MAX) {
    		pr_crit("Ignoring memory at 0x%08llx outside 32-bit physical address space\n",
    			(long long)start);
    		return -EINVAL;
    	}
    
    	if (aligned_start + size > ULONG_MAX) {
    		pr_crit("Truncating memory at 0x%08llx to fit in 32-bit physical address space\n",
    			(long long)start);
    		/*
    		 * To ensure bank->start + bank->size is representable in
    		 * 32 bits, we use ULONG_MAX as the upper limit rather than 4GB.
    		 * This means we lose a page after masking.
    		 */
    		size = ULONG_MAX - aligned_start;
    	}
    #endif
    
    	if (aligned_start < PHYS_OFFSET) {
    		if (aligned_start + size <= PHYS_OFFSET) {
    			pr_info("Ignoring memory below PHYS_OFFSET: 0x%08llx-0x%08llx\n",
    				aligned_start, aligned_start + size);
    			return -EINVAL;
    		}
    
    		pr_info("Ignoring memory below PHYS_OFFSET: 0x%08llx-0x%08llx\n",
    			aligned_start, (u64)PHYS_OFFSET);
    
    		size -= PHYS_OFFSET - aligned_start;
    		aligned_start = PHYS_OFFSET;
    	}
    
    	start = aligned_start;
    	size = size & ~(phys_addr_t)(PAGE_SIZE - 1);
    
    	/*
    	 * Check whether this memory region has non-zero size or
    	 * invalid node number.
    	 */
    	if (size == 0)
    		return -EINVAL;
    
    	memblock_add(start, size);
    	return 0;
    }
    
    /*
     * Pick out the memory size.  We look for mem=size@start,
     * where start and size are "size[KkMm]"
     */
    
    static int __init early_mem(char *p)
    {
    	static int usermem __initdata = 0;
    	u64 size;
    	u64 start;
    	char *endp;
    
    	/*
    	 * If the user specifies memory size, we
    	 * blow away any automatically generated
    	 * size.
    	 */
    	if (usermem == 0) {
    		usermem = 1;
    		memblock_remove(memblock_start_of_DRAM(),
    			memblock_end_of_DRAM() - memblock_start_of_DRAM());
    	}
    
    	start = PHYS_OFFSET;
    	size  = memparse(p, &endp);
    	if (*endp == '@')
    		start = memparse(endp + 1, NULL);
    
    	arm_add_memory(start, size);
    
    	return 0;
    }
    early_param("mem", early_mem);
    
    static void __init request_standard_resources(const struct machine_desc *mdesc)
    {
    	phys_addr_t start, end, res_end;
    	struct resource *res;
    	u64 i;
    
    	kernel_code.start   = virt_to_phys(_text);
    	kernel_code.end     = virt_to_phys(__init_begin - 1);
    	kernel_data.start   = virt_to_phys(_sdata);
    	kernel_data.end     = virt_to_phys(_end - 1);
    
    	for_each_mem_range(i, &start, &end) {
    		unsigned long boot_alias_start;
    
    		/*
    		 * In memblock, end points to the first byte after the
    		 * range while in resourses, end points to the last byte in
    		 * the range.
    		 */
    		res_end = end - 1;
    
    		/*
    		 * Some systems have a special memory alias which is only
    		 * used for booting.  We need to advertise this region to
    		 * kexec-tools so they know where bootable RAM is located.
    		 */
    		boot_alias_start = phys_to_idmap(start);
    		if (arm_has_idmap_alias() && boot_alias_start != IDMAP_INVALID_ADDR) {
    			res = memblock_alloc(sizeof(*res), SMP_CACHE_BYTES);
    			if (!res)
    				panic("%s: Failed to allocate %zu bytes\n",
    				      __func__, sizeof(*res));
    			res->name = "System RAM (boot alias)";
    			res->start = boot_alias_start;
    			res->end = phys_to_idmap(res_end);
    			res->flags = IORESOURCE_MEM | IORESOURCE_BUSY;
    			request_resource(&iomem_resource, res);
    		}
    
    		res = memblock_alloc(sizeof(*res), SMP_CACHE_BYTES);
    		if (!res)
    			panic("%s: Failed to allocate %zu bytes\n", __func__,
    			      sizeof(*res));
    		res->name  = "System RAM";
    		res->start = start;
    		res->end = res_end;
    		res->flags = IORESOURCE_SYSTEM_RAM | IORESOURCE_BUSY;
    
    		request_resource(&iomem_resource, res);
    
    		if (kernel_code.start >= res->start &&
    		    kernel_code.end <= res->end)
    			request_resource(res, &kernel_code);
    		if (kernel_data.start >= res->start &&
    		    kernel_data.end <= res->end)
    			request_resource(res, &kernel_data);
    	}
    
    	if (mdesc->video_start) {
    		video_ram.start = mdesc->video_start;
    		video_ram.end   = mdesc->video_end;
    		request_resource(&iomem_resource, &video_ram);
    	}
    
    	/*
    	 * Some machines don't have the possibility of ever
    	 * possessing lp0, lp1 or lp2
    	 */
    	if (mdesc->reserve_lp0)
    		request_resource(&ioport_resource, &lp0);
    	if (mdesc->reserve_lp1)
    		request_resource(&ioport_resource, &lp1);
    	if (mdesc->reserve_lp2)
    		request_resource(&ioport_resource, &lp2);
    }
    
    #if defined(CONFIG_VGA_CONSOLE) || defined(CONFIG_DUMMY_CONSOLE) || \
        defined(CONFIG_EFI)
    struct screen_info screen_info = {
     .orig_video_lines	= 30,
     .orig_video_cols	= 80,
     .orig_video_mode	= 0,
     .orig_video_ega_bx	= 0,
     .orig_video_isVGA	= 1,
     .orig_video_points	= 8
    };
    #endif
    
    static int __init customize_machine(void)
    {
    	/*
    	 * customizes platform devices, or adds new ones
    	 * On DT based machines, we fall back to populating the
    	 * machine from the device tree, if no callback is provided,
    	 * otherwise we would always need an init_machine callback.
    	 */
    	if (machine_desc->init_machine)
    		machine_desc->init_machine();
    
    	return 0;
    }
    arch_initcall(customize_machine);
    
    static int __init init_machine_late(void)
    {
    	struct device_node *root;
    	int ret;
    
    	if (machine_desc->init_late)
    		machine_desc->init_late();
    
    	root = of_find_node_by_path("/");
    	if (root) {
    		ret = of_property_read_string(root, "serial-number",
    					      &system_serial);
    		if (ret)
    			system_serial = NULL;
    	}
    
    	if (!system_serial)
    		system_serial = kasprintf(GFP_KERNEL, "%08x%08x",
    					  system_serial_high,
    					  system_serial_low);
    
    	return 0;
    }
    late_initcall(init_machine_late);
    
    #ifdef CONFIG_KEXEC
    /*
     * The crash region must be aligned to 128MB to avoid
     * zImage relocating below the reserved region.
     */
    #define CRASH_ALIGN	(128 << 20)
    
    static inline unsigned long long get_total_mem(void)
    {
    	unsigned long total;
    
    	total = max_low_pfn - min_low_pfn;
    	return total << PAGE_SHIFT;
    }
    
    /**
     * reserve_crashkernel() - reserves memory are for crash kernel
     *
     * This function reserves memory area given in "crashkernel=" kernel command
     * line parameter. The memory reserved is used by a dump capture kernel when
     * primary kernel is crashing.
     */
    static void __init reserve_crashkernel(void)
    {
    	unsigned long long crash_size, crash_base;
    	unsigned long long total_mem;
    	int ret;
    
    	total_mem = get_total_mem();
    	ret = parse_crashkernel(boot_command_line, total_mem,
    				&crash_size, &crash_base);
    	if (ret)
    		return;
    
    	if (crash_base <= 0) {
    		unsigned long long crash_max = idmap_to_phys((u32)~0);
    		unsigned long long lowmem_max = __pa(high_memory - 1) + 1;
    		if (crash_max > lowmem_max)
    			crash_max = lowmem_max;
    		crash_base = memblock_find_in_range(CRASH_ALIGN, crash_max,
    						    crash_size, CRASH_ALIGN);
    		if (!crash_base) {
    			pr_err("crashkernel reservation failed - No suitable area found.\n");
    			return;
    		}
    	} else {
    		unsigned long long start;
    
    		start = memblock_find_in_range(crash_base,
    					       crash_base + crash_size,
    					       crash_size, SECTION_SIZE);
    		if (start != crash_base) {
    			pr_err("crashkernel reservation failed - memory is in use.\n");
    			return;
    		}
    	}
    
    	ret = memblock_reserve(crash_base, crash_size);
    	if (ret < 0) {
    		pr_warn("crashkernel reservation failed - memory is in use (0x%lx)\n",
    			(unsigned long)crash_base);
    		return;
    	}
    
    	pr_info("Reserving %ldMB of memory at %ldMB for crashkernel (System RAM: %ldMB)\n",
    		(unsigned long)(crash_size >> 20),
    		(unsigned long)(crash_base >> 20),
    		(unsigned long)(total_mem >> 20));
    
    	/* The crashk resource must always be located in normal mem */
    	crashk_res.start = crash_base;
    	crashk_res.end = crash_base + crash_size - 1;
    	insert_resource(&iomem_resource, &crashk_res);
    
    	if (arm_has_idmap_alias()) {
    		/*
    		 * If we have a special RAM alias for use at boot, we
    		 * need to advertise to kexec tools where the alias is.
    		 */
    		static struct resource crashk_boot_res = {
    			.name = "Crash kernel (boot alias)",
    			.flags = IORESOURCE_BUSY | IORESOURCE_MEM,
    		};
    
    		crashk_boot_res.start = phys_to_idmap(crash_base);
    		crashk_boot_res.end = crashk_boot_res.start + crash_size - 1;
    		insert_resource(&iomem_resource, &crashk_boot_res);
    	}
    }
    #else
    static inline void reserve_crashkernel(void) {}
    #endif /* CONFIG_KEXEC */
    
    void __init hyp_mode_check(void)
    {
    #ifdef CONFIG_ARM_VIRT_EXT
    	sync_boot_mode();
    
    	if (is_hyp_mode_available()) {
    		pr_info("CPU: All CPU(s) started in HYP mode.\n");
    		pr_info("CPU: Virtualization extensions available.\n");
    	} else if (is_hyp_mode_mismatched()) {
    		pr_warn("CPU: WARNING: CPU(s) started in wrong/inconsistent modes (primary CPU mode 0x%x)\n",
    			__boot_cpu_mode & MODE_MASK);
    		pr_warn("CPU: This may indicate a broken bootloader or firmware.\n");
    	} else
    		pr_info("CPU: All CPU(s) started in SVC mode.\n");
    #endif
    }
    
    void __init setup_arch(char **cmdline_p)
    {
    	const struct machine_desc *mdesc = NULL;
    	void *atags_vaddr = NULL;
    
    	if (__atags_pointer)
    		atags_vaddr = FDT_VIRT_BASE(__atags_pointer);
    
    	setup_processor();
    	if (atags_vaddr) {
    		mdesc = setup_machine_fdt(atags_vaddr);
    		if (mdesc)
    			memblock_reserve(__atags_pointer,
    					 fdt_totalsize(atags_vaddr));
    	}
    	if (!mdesc)
    		mdesc = setup_machine_tags(atags_vaddr, __machine_arch_type);
    	if (!mdesc) {
    		early_print("\nError: invalid dtb and unrecognized/unsupported machine ID\n");
    		early_print("  r1=0x%08x, r2=0x%08x\n", __machine_arch_type,
    			    __atags_pointer);
    		if (__atags_pointer)
    			early_print("  r2[]=%*ph\n", 16, atags_vaddr);
    		dump_machine_table();
    	}
    
    	machine_desc = mdesc;
    	machine_name = mdesc->name;
    	dump_stack_set_arch_desc("%s", mdesc->name);
    
    	if (mdesc->reboot_mode != REBOOT_HARD)
    		reboot_mode = mdesc->reboot_mode;
    
    	init_mm.start_code = (unsigned long) _text;
    	init_mm.end_code   = (unsigned long) _etext;
    	init_mm.end_data   = (unsigned long) _edata;
    	init_mm.brk	   = (unsigned long) _end;
    
    	/* populate cmd_line too for later use, preserving boot_command_line */
    	strlcpy(cmd_line, boot_command_line, COMMAND_LINE_SIZE);
    	*cmdline_p = cmd_line;
    
    	early_fixmap_init();
    	early_ioremap_init();
    
    	parse_early_param();
    
    #ifdef CONFIG_MMU
    	early_mm_init(mdesc);
    #endif
    	setup_dma_zone(mdesc);
    	xen_early_init();
    	efi_init();
    	/*
    	 * Make sure the calculation for lowmem/highmem is set appropriately
    	 * before reserving/allocating any mmeory
    	 */
    	adjust_lowmem_bounds();
    	arm_memblock_init(mdesc);
    	/* Memory may have been removed so recalculate the bounds. */
    	adjust_lowmem_bounds();
    
    	early_ioremap_reset();
    
    	paging_init(mdesc);
    	request_standard_resources(mdesc);
    
    	if (mdesc->restart)
    		arm_pm_restart = mdesc->restart;
    
    	unflatten_device_tree();
    
    	arm_dt_init_cpu_maps();
    	psci_dt_init();
    #ifdef CONFIG_SMP
    	if (is_smp()) {
    		if (!mdesc->smp_init || !mdesc->smp_init()) {
    			if (psci_smp_available())
    				smp_set_ops(&psci_smp_ops);
    			else if (mdesc->smp)
    				smp_set_ops(mdesc->smp);
    		}
    		smp_init_cpus();
    		smp_build_mpidr_hash();
    	}
    #endif
    
    	if (!is_smp())
    		hyp_mode_check();
    
    	reserve_crashkernel();
    
    #ifdef CONFIG_GENERIC_IRQ_MULTI_HANDLER
    	handle_arch_irq = mdesc->handle_irq;
    #endif
    
    #ifdef CONFIG_VT
    #if defined(CONFIG_VGA_CONSOLE)
    	conswitchp = &vga_con;
    #endif
    #endif
    
    	if (mdesc->init_early)
    		mdesc->init_early();
    }
    
    
    static int __init topology_init(void)
    {
    	int cpu;
    
    	for_each_possible_cpu(cpu) {
    		struct cpuinfo_arm *cpuinfo = &per_cpu(cpu_data, cpu);
    		cpuinfo->cpu.hotpluggable = platform_can_hotplug_cpu(cpu);
    		register_cpu(&cpuinfo->cpu, cpu);
    	}
    
    	return 0;
    }
    subsys_initcall(topology_init);
    
    #ifdef CONFIG_HAVE_PROC_CPU
    static int __init proc_cpu_init(void)
    {
    	struct proc_dir_entry *res;
    
    	res = proc_mkdir("cpu", NULL);
    	if (!res)
    		return -ENOMEM;
    	return 0;
    }
    fs_initcall(proc_cpu_init);
    #endif
    
    static const char *hwcap_str[] = {
    	"swp",
    	"half",
    	"thumb",
    	"26bit",
    	"fastmult",
    	"fpa",
    	"vfp",
    	"edsp",
    	"java",
    	"iwmmxt",
    	"crunch",
    	"thumbee",
    	"neon",
    	"vfpv3",
    	"vfpv3d16",
    	"tls",
    	"vfpv4",
    	"idiva",
    	"idivt",
    	"vfpd32",
    	"lpae",
    	"evtstrm",
    	NULL
    };
    
    static const char *hwcap2_str[] = {
    	"aes",
    	"pmull",
    	"sha1",
    	"sha2",
    	"crc32",
    	NULL
    };
    
    static int c_show(struct seq_file *m, void *v)
    {
    	int i, j;
    	u32 cpuid;
    
    	for_each_online_cpu(i) {
    		/*
    		 * glibc reads /proc/cpuinfo to determine the number of
    		 * online processors, looking for lines beginning with
    		 * "processor".  Give glibc what it expects.
    		 */
    		seq_printf(m, "processor\t: %d\n", i);
    		cpuid = is_smp() ? per_cpu(cpu_data, i).cpuid : read_cpuid_id();
    		seq_printf(m, "model name\t: %s rev %d (%s)\n",
    			   cpu_name, cpuid & 15, elf_platform);
    
    #if defined(CONFIG_SMP)
    		seq_printf(m, "BogoMIPS\t: %lu.%02lu\n",
    			   per_cpu(cpu_data, i).loops_per_jiffy / (500000UL/HZ),
    			   (per_cpu(cpu_data, i).loops_per_jiffy / (5000UL/HZ)) % 100);
    #else
    		seq_printf(m, "BogoMIPS\t: %lu.%02lu\n",
    			   loops_per_jiffy / (500000/HZ),
    			   (loops_per_jiffy / (5000/HZ)) % 100);
    #endif
    		/* dump out the processor features */
    		seq_puts(m, "Features\t: ");
    
    		for (j = 0; hwcap_str[j]; j++)
    			if (elf_hwcap & (1 << j))
    				seq_printf(m, "%s ", hwcap_str[j]);
    
    		for (j = 0; hwcap2_str[j]; j++)
    			if (elf_hwcap2 & (1 << j))
    				seq_printf(m, "%s ", hwcap2_str[j]);
    
    		seq_printf(m, "\nCPU implementer\t: 0x%02x\n", cpuid >> 24);
    		seq_printf(m, "CPU architecture: %s\n",
    			   proc_arch[cpu_architecture()]);
    
    		if ((cpuid & 0x0008f000) == 0x00000000) {
    			/* pre-ARM7 */
    			seq_printf(m, "CPU part\t: %07x\n", cpuid >> 4);
    		} else {
    			if ((cpuid & 0x0008f000) == 0x00007000) {
    				/* ARM7 */
    				seq_printf(m, "CPU variant\t: 0x%02x\n",
    					   (cpuid >> 16) & 127);
    			} else {
    				/* post-ARM7 */
    				seq_printf(m, "CPU variant\t: 0x%x\n",
    					   (cpuid >> 20) & 15);
    			}
    			seq_printf(m, "CPU part\t: 0x%03x\n",
    				   (cpuid >> 4) & 0xfff);
    		}
    		seq_printf(m, "CPU revision\t: %d\n\n", cpuid & 15);
    	}
    
    	seq_printf(m, "Hardware\t: %s\n", machine_name);
    	seq_printf(m, "Revision\t: %04x\n", system_rev);
    	seq_printf(m, "Serial\t\t: %s\n", system_serial);
    
    	return 0;
    }
    
    static void *c_start(struct seq_file *m, loff_t *pos)
    {
    	return *pos < 1 ? (void *)1 : NULL;
    }
    
    static void *c_next(struct seq_file *m, void *v, loff_t *pos)
    {
    	++*pos;
    	return NULL;
    }
    
    static void c_stop(struct seq_file *m, void *v)
    {
    }
    
    const struct seq_operations cpuinfo_op = {
    	.start	= c_start,
    	.next	= c_next,
    	.stop	= c_stop,
    	.show	= c_show
    };