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32 results

memcontrol.c

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  • setup.c 28.57 KiB
    // SPDX-License-Identifier: GPL-2.0
    /*
     *  S390 version
     *    Copyright IBM Corp. 1999, 2012
     *    Author(s): Hartmut Penner (hp@de.ibm.com),
     *               Martin Schwidefsky (schwidefsky@de.ibm.com)
     *
     *  Derived from "arch/i386/kernel/setup.c"
     *    Copyright (C) 1995, Linus Torvalds
     */
    
    /*
     * This file handles the architecture-dependent parts of initialization
     */
    
    #define KMSG_COMPONENT "setup"
    #define pr_fmt(fmt) KMSG_COMPONENT ": " fmt
    
    #include <linux/errno.h>
    #include <linux/export.h>
    #include <linux/sched.h>
    #include <linux/sched/task.h>
    #include <linux/cpu.h>
    #include <linux/kernel.h>
    #include <linux/memblock.h>
    #include <linux/mm.h>
    #include <linux/stddef.h>
    #include <linux/unistd.h>
    #include <linux/ptrace.h>
    #include <linux/random.h>
    #include <linux/user.h>
    #include <linux/tty.h>
    #include <linux/ioport.h>
    #include <linux/delay.h>
    #include <linux/init.h>
    #include <linux/initrd.h>
    #include <linux/root_dev.h>
    #include <linux/console.h>
    #include <linux/kernel_stat.h>
    #include <linux/dma-map-ops.h>
    #include <linux/device.h>
    #include <linux/notifier.h>
    #include <linux/pfn.h>
    #include <linux/ctype.h>
    #include <linux/reboot.h>
    #include <linux/topology.h>
    #include <linux/kexec.h>
    #include <linux/crash_dump.h>
    #include <linux/memory.h>
    #include <linux/compat.h>
    #include <linux/start_kernel.h>
    #include <linux/hugetlb.h>
    #include <linux/kmemleak.h>
    
    #include <asm/boot_data.h>
    #include <asm/ipl.h>
    #include <asm/facility.h>
    #include <asm/smp.h>
    #include <asm/mmu_context.h>
    #include <asm/cpcmd.h>
    #include <asm/lowcore.h>
    #include <asm/nmi.h>
    #include <asm/irq.h>
    #include <asm/page.h>
    #include <asm/ptrace.h>
    #include <asm/sections.h>
    #include <asm/ebcdic.h>
    #include <asm/diag.h>
    #include <asm/os_info.h>
    #include <asm/sclp.h>
    #include <asm/stacktrace.h>
    #include <asm/sysinfo.h>
    #include <asm/numa.h>
    #include <asm/alternative.h>
    #include <asm/nospec-branch.h>
    #include <asm/mem_detect.h>
    #include <asm/uv.h>
    #include <asm/asm-offsets.h>
    #include "entry.h"
    
    /*
     * Machine setup..
     */
    unsigned int console_mode = 0;
    EXPORT_SYMBOL(console_mode);
    
    unsigned int console_devno = -1;
    EXPORT_SYMBOL(console_devno);
    
    unsigned int console_irq = -1;
    EXPORT_SYMBOL(console_irq);
    
    /*
     * Some code and data needs to stay below 2 GB, even when the kernel would be
     * relocated above 2 GB, because it has to use 31 bit addresses.
     * Such code and data is part of the .amode31 section.
     */
    unsigned long __amode31_ref __samode31 = (unsigned long)&_samode31;
    unsigned long __amode31_ref __eamode31 = (unsigned long)&_eamode31;
    unsigned long __amode31_ref __stext_amode31 = (unsigned long)&_stext_amode31;
    unsigned long __amode31_ref __etext_amode31 = (unsigned long)&_etext_amode31;
    struct exception_table_entry __amode31_ref *__start_amode31_ex_table = _start_amode31_ex_table;
    struct exception_table_entry __amode31_ref *__stop_amode31_ex_table = _stop_amode31_ex_table;
    
    /*
     * Control registers CR2, CR5 and CR15 are initialized with addresses
     * of tables that must be placed below 2G which is handled by the AMODE31
     * sections.
     * Because the AMODE31 sections are relocated below 2G at startup,
     * the content of control registers CR2, CR5 and CR15 must be updated
     * with new addresses after the relocation. The initial initialization of
     * control registers occurs in head64.S and then gets updated again after AMODE31
     * relocation. We must access the relevant AMODE31 tables indirectly via
     * pointers placed in the .amode31.refs linker section. Those pointers get
     * updated automatically during AMODE31 relocation and always contain a valid
     * address within AMODE31 sections.
     */
    
    static __amode31_data u32 __ctl_duct_amode31[16] __aligned(64);
    
    static __amode31_data u64 __ctl_aste_amode31[8] __aligned(64) = {
    	[1] = 0xffffffffffffffff
    };
    
    static __amode31_data u32 __ctl_duald_amode31[32] __aligned(128) = {
    	0x80000000, 0, 0, 0,
    	0x80000000, 0, 0, 0,
    	0x80000000, 0, 0, 0,
    	0x80000000, 0, 0, 0,
    	0x80000000, 0, 0, 0,
    	0x80000000, 0, 0, 0,
    	0x80000000, 0, 0, 0,
    	0x80000000, 0, 0, 0
    };
    
    static __amode31_data u32 __ctl_linkage_stack_amode31[8] __aligned(64) = {
    	0, 0, 0x89000000, 0,
    	0, 0, 0x8a000000, 0
    };
    
    static u64 __amode31_ref *__ctl_aste = __ctl_aste_amode31;
    static u32 __amode31_ref *__ctl_duald = __ctl_duald_amode31;
    static u32 __amode31_ref *__ctl_linkage_stack = __ctl_linkage_stack_amode31;
    static u32 __amode31_ref *__ctl_duct = __ctl_duct_amode31;
    
    int __bootdata(noexec_disabled);
    unsigned long __bootdata(ident_map_size);
    struct mem_detect_info __bootdata(mem_detect);
    struct initrd_data __bootdata(initrd_data);
    
    unsigned long __bootdata_preserved(__kaslr_offset);
    unsigned long __bootdata(__amode31_base);
    unsigned int __bootdata_preserved(zlib_dfltcc_support);
    EXPORT_SYMBOL(zlib_dfltcc_support);
    u64 __bootdata_preserved(stfle_fac_list[16]);
    EXPORT_SYMBOL(stfle_fac_list);
    u64 __bootdata_preserved(alt_stfle_fac_list[16]);
    struct oldmem_data __bootdata_preserved(oldmem_data);
    
    unsigned long VMALLOC_START;
    EXPORT_SYMBOL(VMALLOC_START);
    
    unsigned long VMALLOC_END;
    EXPORT_SYMBOL(VMALLOC_END);
    
    struct page *vmemmap;
    EXPORT_SYMBOL(vmemmap);
    unsigned long vmemmap_size;
    
    unsigned long MODULES_VADDR;
    unsigned long MODULES_END;
    
    /* An array with a pointer to the lowcore of every CPU. */
    struct lowcore *lowcore_ptr[NR_CPUS];
    EXPORT_SYMBOL(lowcore_ptr);
    
    DEFINE_STATIC_KEY_FALSE(cpu_has_bear);
    
    /*
     * The Write Back bit position in the physaddr is given by the SLPC PCI.
     * Leaving the mask zero always uses write through which is safe
     */
    unsigned long mio_wb_bit_mask __ro_after_init;
    
    /*
     * This is set up by the setup-routine at boot-time
     * for S390 need to find out, what we have to setup
     * using address 0x10400 ...
     */
    
    #include <asm/setup.h>
    
    /*
     * condev= and conmode= setup parameter.
     */
    
    static int __init condev_setup(char *str)
    {
    	int vdev;
    
    	vdev = simple_strtoul(str, &str, 0);
    	if (vdev >= 0 && vdev < 65536) {
    		console_devno = vdev;
    		console_irq = -1;
    	}
    	return 1;
    }
    
    __setup("condev=", condev_setup);
    
    static void __init set_preferred_console(void)
    {
    	if (CONSOLE_IS_3215 || CONSOLE_IS_SCLP)
    		add_preferred_console("ttyS", 0, NULL);
    	else if (CONSOLE_IS_3270)
    		add_preferred_console("tty3270", 0, NULL);
    	else if (CONSOLE_IS_VT220)
    		add_preferred_console("ttysclp", 0, NULL);
    	else if (CONSOLE_IS_HVC)
    		add_preferred_console("hvc", 0, NULL);
    }
    
    static int __init conmode_setup(char *str)
    {
    #if defined(CONFIG_SCLP_CONSOLE) || defined(CONFIG_SCLP_VT220_CONSOLE)
    	if (!strcmp(str, "hwc") || !strcmp(str, "sclp"))
                    SET_CONSOLE_SCLP;
    #endif
    #if defined(CONFIG_TN3215_CONSOLE)
    	if (!strcmp(str, "3215"))
    		SET_CONSOLE_3215;
    #endif
    #if defined(CONFIG_TN3270_CONSOLE)
    	if (!strcmp(str, "3270"))
    		SET_CONSOLE_3270;
    #endif
    	set_preferred_console();
            return 1;
    }
    
    __setup("conmode=", conmode_setup);
    
    static void __init conmode_default(void)
    {
    	char query_buffer[1024];
    	char *ptr;
    
            if (MACHINE_IS_VM) {
    		cpcmd("QUERY CONSOLE", query_buffer, 1024, NULL);
    		console_devno = simple_strtoul(query_buffer + 5, NULL, 16);
    		ptr = strstr(query_buffer, "SUBCHANNEL =");
    		console_irq = simple_strtoul(ptr + 13, NULL, 16);
    		cpcmd("QUERY TERM", query_buffer, 1024, NULL);
    		ptr = strstr(query_buffer, "CONMODE");
    		/*
    		 * Set the conmode to 3215 so that the device recognition 
    		 * will set the cu_type of the console to 3215. If the
    		 * conmode is 3270 and we don't set it back then both
    		 * 3215 and the 3270 driver will try to access the console
    		 * device (3215 as console and 3270 as normal tty).
    		 */
    		cpcmd("TERM CONMODE 3215", NULL, 0, NULL);
    		if (ptr == NULL) {
    #if defined(CONFIG_SCLP_CONSOLE) || defined(CONFIG_SCLP_VT220_CONSOLE)
    			SET_CONSOLE_SCLP;
    #endif
    			return;
    		}
    		if (str_has_prefix(ptr + 8, "3270")) {
    #if defined(CONFIG_TN3270_CONSOLE)
    			SET_CONSOLE_3270;
    #elif defined(CONFIG_TN3215_CONSOLE)
    			SET_CONSOLE_3215;
    #elif defined(CONFIG_SCLP_CONSOLE) || defined(CONFIG_SCLP_VT220_CONSOLE)
    			SET_CONSOLE_SCLP;
    #endif
    		} else if (str_has_prefix(ptr + 8, "3215")) {
    #if defined(CONFIG_TN3215_CONSOLE)
    			SET_CONSOLE_3215;
    #elif defined(CONFIG_TN3270_CONSOLE)
    			SET_CONSOLE_3270;
    #elif defined(CONFIG_SCLP_CONSOLE) || defined(CONFIG_SCLP_VT220_CONSOLE)
    			SET_CONSOLE_SCLP;
    #endif
    		}
    	} else if (MACHINE_IS_KVM) {
    		if (sclp.has_vt220 && IS_ENABLED(CONFIG_SCLP_VT220_CONSOLE))
    			SET_CONSOLE_VT220;
    		else if (sclp.has_linemode && IS_ENABLED(CONFIG_SCLP_CONSOLE))
    			SET_CONSOLE_SCLP;
    		else
    			SET_CONSOLE_HVC;
    	} else {
    #if defined(CONFIG_SCLP_CONSOLE) || defined(CONFIG_SCLP_VT220_CONSOLE)
    		SET_CONSOLE_SCLP;
    #endif
    	}
    }
    
    #ifdef CONFIG_CRASH_DUMP
    static void __init setup_zfcpdump(void)
    {
    	if (!is_ipl_type_dump())
    		return;
    	if (oldmem_data.start)
    		return;
    	strcat(boot_command_line, " cio_ignore=all,!ipldev,!condev");
    	console_loglevel = 2;
    }
    #else
    static inline void setup_zfcpdump(void) {}
    #endif /* CONFIG_CRASH_DUMP */
    
     /*
     * Reboot, halt and power_off stubs. They just call _machine_restart,
     * _machine_halt or _machine_power_off. 
     */
    
    void machine_restart(char *command)
    {
    	if ((!in_interrupt() && !in_atomic()) || oops_in_progress)
    		/*
    		 * Only unblank the console if we are called in enabled
    		 * context or a bust_spinlocks cleared the way for us.
    		 */
    		console_unblank();
    	_machine_restart(command);
    }
    
    void machine_halt(void)
    {
    	if (!in_interrupt() || oops_in_progress)
    		/*
    		 * Only unblank the console if we are called in enabled
    		 * context or a bust_spinlocks cleared the way for us.
    		 */
    		console_unblank();
    	_machine_halt();
    }
    
    void machine_power_off(void)
    {
    	if (!in_interrupt() || oops_in_progress)
    		/*
    		 * Only unblank the console if we are called in enabled
    		 * context or a bust_spinlocks cleared the way for us.
    		 */
    		console_unblank();
    	_machine_power_off();
    }
    
    void *restart_stack;
    
    unsigned long stack_alloc(void)
    {
    #ifdef CONFIG_VMAP_STACK
    	void *ret;
    
    	ret = __vmalloc_node(THREAD_SIZE, THREAD_SIZE, THREADINFO_GFP,
    			     NUMA_NO_NODE, __builtin_return_address(0));
    	kmemleak_not_leak(ret);
    	return (unsigned long)ret;
    #else
    	return __get_free_pages(GFP_KERNEL, THREAD_SIZE_ORDER);
    #endif
    }
    
    void stack_free(unsigned long stack)
    {
    #ifdef CONFIG_VMAP_STACK
    	vfree((void *) stack);
    #else
    	free_pages(stack, THREAD_SIZE_ORDER);
    #endif
    }
    
    int __init arch_early_irq_init(void)
    {
    	unsigned long stack;
    
    	stack = __get_free_pages(GFP_KERNEL, THREAD_SIZE_ORDER);
    	if (!stack)
    		panic("Couldn't allocate async stack");
    	S390_lowcore.async_stack = stack + STACK_INIT_OFFSET;
    	return 0;
    }
    
    void __init arch_call_rest_init(void)
    {
    	unsigned long stack;
    
    	stack = stack_alloc();
    	if (!stack)
    		panic("Couldn't allocate kernel stack");
    	current->stack = (void *) stack;
    #ifdef CONFIG_VMAP_STACK
    	current->stack_vm_area = (void *) stack;
    #endif
    	set_task_stack_end_magic(current);
    	stack += STACK_INIT_OFFSET;
    	S390_lowcore.kernel_stack = stack;
    	call_on_stack_noreturn(rest_init, stack);
    }
    
    static void __init setup_lowcore_dat_off(void)
    {
    	unsigned long int_psw_mask = PSW_KERNEL_BITS;
    	unsigned long mcck_stack;
    	struct lowcore *lc;
    
    	if (IS_ENABLED(CONFIG_KASAN))
    		int_psw_mask |= PSW_MASK_DAT;
    
    	/*
    	 * Setup lowcore for boot cpu
    	 */
    	BUILD_BUG_ON(sizeof(struct lowcore) != LC_PAGES * PAGE_SIZE);
    	lc = memblock_alloc_low(sizeof(*lc), sizeof(*lc));
    	if (!lc)
    		panic("%s: Failed to allocate %zu bytes align=%zx\n",
    		      __func__, sizeof(*lc), sizeof(*lc));
    
    	lc->restart_psw.mask = PSW_KERNEL_BITS;
    	lc->restart_psw.addr = (unsigned long) restart_int_handler;
    	lc->external_new_psw.mask = int_psw_mask | PSW_MASK_MCHECK;
    	lc->external_new_psw.addr = (unsigned long) ext_int_handler;
    	lc->svc_new_psw.mask = int_psw_mask | PSW_MASK_MCHECK;
    	lc->svc_new_psw.addr = (unsigned long) system_call;
    	lc->program_new_psw.mask = int_psw_mask | PSW_MASK_MCHECK;
    	lc->program_new_psw.addr = (unsigned long) pgm_check_handler;
    	lc->mcck_new_psw.mask = PSW_KERNEL_BITS;
    	lc->mcck_new_psw.addr = (unsigned long) mcck_int_handler;
    	lc->io_new_psw.mask = int_psw_mask | PSW_MASK_MCHECK;
    	lc->io_new_psw.addr = (unsigned long) io_int_handler;
    	lc->clock_comparator = clock_comparator_max;
    	lc->nodat_stack = ((unsigned long) &init_thread_union)
    		+ THREAD_SIZE - STACK_FRAME_OVERHEAD - sizeof(struct pt_regs);
    	lc->current_task = (unsigned long)&init_task;
    	lc->lpp = LPP_MAGIC;
    	lc->machine_flags = S390_lowcore.machine_flags;
    	lc->preempt_count = S390_lowcore.preempt_count;
    	nmi_alloc_mcesa_early(&lc->mcesad);
    	lc->sys_enter_timer = S390_lowcore.sys_enter_timer;
    	lc->exit_timer = S390_lowcore.exit_timer;
    	lc->user_timer = S390_lowcore.user_timer;
    	lc->system_timer = S390_lowcore.system_timer;
    	lc->steal_timer = S390_lowcore.steal_timer;
    	lc->last_update_timer = S390_lowcore.last_update_timer;
    	lc->last_update_clock = S390_lowcore.last_update_clock;
    
    	/*
    	 * Allocate the global restart stack which is the same for
    	 * all CPUs in cast *one* of them does a PSW restart.
    	 */
    	restart_stack = memblock_alloc(THREAD_SIZE, THREAD_SIZE);
    	if (!restart_stack)
    		panic("%s: Failed to allocate %lu bytes align=0x%lx\n",
    		      __func__, THREAD_SIZE, THREAD_SIZE);
    	restart_stack += STACK_INIT_OFFSET;
    
    	/*
    	 * Set up PSW restart to call ipl.c:do_restart(). Copy the relevant
    	 * restart data to the absolute zero lowcore. This is necessary if
    	 * PSW restart is done on an offline CPU that has lowcore zero.
    	 */
    	lc->restart_stack = (unsigned long) restart_stack;
    	lc->restart_fn = (unsigned long) do_restart;
    	lc->restart_data = 0;
    	lc->restart_source = -1U;
    
    	mcck_stack = (unsigned long)memblock_alloc(THREAD_SIZE, THREAD_SIZE);
    	if (!mcck_stack)
    		panic("%s: Failed to allocate %lu bytes align=0x%lx\n",
    		      __func__, THREAD_SIZE, THREAD_SIZE);
    	lc->mcck_stack = mcck_stack + STACK_INIT_OFFSET;
    
    	/* Setup absolute zero lowcore */
    	put_abs_lowcore(restart_stack, lc->restart_stack);
    	put_abs_lowcore(restart_fn, lc->restart_fn);
    	put_abs_lowcore(restart_data, lc->restart_data);
    	put_abs_lowcore(restart_source, lc->restart_source);
    	put_abs_lowcore(restart_psw, lc->restart_psw);
    
    	lc->spinlock_lockval = arch_spin_lockval(0);
    	lc->spinlock_index = 0;
    	arch_spin_lock_setup(0);
    	lc->return_lpswe = gen_lpswe(__LC_RETURN_PSW);
    	lc->return_mcck_lpswe = gen_lpswe(__LC_RETURN_MCCK_PSW);
    	lc->preempt_count = PREEMPT_DISABLED;
    
    	set_prefix((u32)(unsigned long) lc);
    	lowcore_ptr[0] = lc;
    }
    
    static void __init setup_lowcore_dat_on(void)
    {
    	struct lowcore *lc = lowcore_ptr[0];
    	int cr;
    
    	__ctl_clear_bit(0, 28);
    	S390_lowcore.external_new_psw.mask |= PSW_MASK_DAT;
    	S390_lowcore.svc_new_psw.mask |= PSW_MASK_DAT;
    	S390_lowcore.program_new_psw.mask |= PSW_MASK_DAT;
    	S390_lowcore.io_new_psw.mask |= PSW_MASK_DAT;
    	__ctl_store(S390_lowcore.cregs_save_area, 0, 15);
    	__ctl_set_bit(0, 28);
    	put_abs_lowcore(restart_flags, RESTART_FLAG_CTLREGS);
    	put_abs_lowcore(program_new_psw, lc->program_new_psw);
    	for (cr = 0; cr < ARRAY_SIZE(lc->cregs_save_area); cr++)
    		put_abs_lowcore(cregs_save_area[cr], lc->cregs_save_area[cr]);
    }
    
    static struct resource code_resource = {
    	.name  = "Kernel code",
    	.flags = IORESOURCE_BUSY | IORESOURCE_SYSTEM_RAM,
    };
    
    static struct resource data_resource = {
    	.name = "Kernel data",
    	.flags = IORESOURCE_BUSY | IORESOURCE_SYSTEM_RAM,
    };
    
    static struct resource bss_resource = {
    	.name = "Kernel bss",
    	.flags = IORESOURCE_BUSY | IORESOURCE_SYSTEM_RAM,
    };
    
    static struct resource __initdata *standard_resources[] = {
    	&code_resource,
    	&data_resource,
    	&bss_resource,
    };
    
    static void __init setup_resources(void)
    {
    	struct resource *res, *std_res, *sub_res;
    	phys_addr_t start, end;
    	int j;
    	u64 i;
    
    	code_resource.start = (unsigned long) _text;
    	code_resource.end = (unsigned long) _etext - 1;
    	data_resource.start = (unsigned long) _etext;
    	data_resource.end = (unsigned long) _edata - 1;
    	bss_resource.start = (unsigned long) __bss_start;
    	bss_resource.end = (unsigned long) __bss_stop - 1;
    
    	for_each_mem_range(i, &start, &end) {
    		res = memblock_alloc(sizeof(*res), 8);
    		if (!res)
    			panic("%s: Failed to allocate %zu bytes align=0x%x\n",
    			      __func__, sizeof(*res), 8);
    		res->flags = IORESOURCE_BUSY | IORESOURCE_SYSTEM_RAM;
    
    		res->name = "System RAM";
    		res->start = 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;
    		request_resource(&iomem_resource, res);
    
    		for (j = 0; j < ARRAY_SIZE(standard_resources); j++) {
    			std_res = standard_resources[j];
    			if (std_res->start < res->start ||
    			    std_res->start > res->end)
    				continue;
    			if (std_res->end > res->end) {
    				sub_res = memblock_alloc(sizeof(*sub_res), 8);
    				if (!sub_res)
    					panic("%s: Failed to allocate %zu bytes align=0x%x\n",
    					      __func__, sizeof(*sub_res), 8);
    				*sub_res = *std_res;
    				sub_res->end = res->end;
    				std_res->start = res->end + 1;
    				request_resource(res, sub_res);
    			} else {
    				request_resource(res, std_res);
    			}
    		}
    	}
    #ifdef CONFIG_CRASH_DUMP
    	/*
    	 * Re-add removed crash kernel memory as reserved memory. This makes
    	 * sure it will be mapped with the identity mapping and struct pages
    	 * will be created, so it can be resized later on.
    	 * However add it later since the crash kernel resource should not be
    	 * part of the System RAM resource.
    	 */
    	if (crashk_res.end) {
    		memblock_add_node(crashk_res.start, resource_size(&crashk_res),
    				  0, MEMBLOCK_NONE);
    		memblock_reserve(crashk_res.start, resource_size(&crashk_res));
    		insert_resource(&iomem_resource, &crashk_res);
    	}
    #endif
    }
    
    static void __init setup_memory_end(void)
    {
    	memblock_remove(ident_map_size, PHYS_ADDR_MAX - ident_map_size);
    	max_pfn = max_low_pfn = PFN_DOWN(ident_map_size);
    	pr_notice("The maximum memory size is %luMB\n", ident_map_size >> 20);
    }
    
    #ifdef CONFIG_CRASH_DUMP
    
    /*
     * When kdump is enabled, we have to ensure that no memory from the area
     * [0 - crashkernel memory size] is set offline - it will be exchanged with
     * the crashkernel memory region when kdump is triggered. The crashkernel
     * memory region can never get offlined (pages are unmovable).
     */
    static int kdump_mem_notifier(struct notifier_block *nb,
    			      unsigned long action, void *data)
    {
    	struct memory_notify *arg = data;
    
    	if (action != MEM_GOING_OFFLINE)
    		return NOTIFY_OK;
    	if (arg->start_pfn < PFN_DOWN(resource_size(&crashk_res)))
    		return NOTIFY_BAD;
    	return NOTIFY_OK;
    }
    
    static struct notifier_block kdump_mem_nb = {
    	.notifier_call = kdump_mem_notifier,
    };
    
    #endif
    
    /*
     * Reserve memory for kdump kernel to be loaded with kexec
     */
    static void __init reserve_crashkernel(void)
    {
    #ifdef CONFIG_CRASH_DUMP
    	unsigned long long crash_base, crash_size;
    	phys_addr_t low, high;
    	int rc;
    
    	rc = parse_crashkernel(boot_command_line, ident_map_size, &crash_size,
    			       &crash_base);
    
    	crash_base = ALIGN(crash_base, KEXEC_CRASH_MEM_ALIGN);
    	crash_size = ALIGN(crash_size, KEXEC_CRASH_MEM_ALIGN);
    	if (rc || crash_size == 0)
    		return;
    
    	if (memblock.memory.regions[0].size < crash_size) {
    		pr_info("crashkernel reservation failed: %s\n",
    			"first memory chunk must be at least crashkernel size");
    		return;
    	}
    
    	low = crash_base ?: oldmem_data.start;
    	high = low + crash_size;
    	if (low >= oldmem_data.start && high <= oldmem_data.start + oldmem_data.size) {
    		/* The crashkernel fits into OLDMEM, reuse OLDMEM */
    		crash_base = low;
    	} else {
    		/* Find suitable area in free memory */
    		low = max_t(unsigned long, crash_size, sclp.hsa_size);
    		high = crash_base ? crash_base + crash_size : ULONG_MAX;
    
    		if (crash_base && crash_base < low) {
    			pr_info("crashkernel reservation failed: %s\n",
    				"crash_base too low");
    			return;
    		}
    		low = crash_base ?: low;
    		crash_base = memblock_phys_alloc_range(crash_size,
    						       KEXEC_CRASH_MEM_ALIGN,
    						       low, high);
    	}
    
    	if (!crash_base) {
    		pr_info("crashkernel reservation failed: %s\n",
    			"no suitable area found");
    		return;
    	}
    
    	if (register_memory_notifier(&kdump_mem_nb)) {
    		memblock_phys_free(crash_base, crash_size);
    		return;
    	}
    
    	if (!oldmem_data.start && MACHINE_IS_VM)
    		diag10_range(PFN_DOWN(crash_base), PFN_DOWN(crash_size));
    	crashk_res.start = crash_base;
    	crashk_res.end = crash_base + crash_size - 1;
    	memblock_remove(crash_base, crash_size);
    	pr_info("Reserving %lluMB of memory at %lluMB "
    		"for crashkernel (System RAM: %luMB)\n",
    		crash_size >> 20, crash_base >> 20,
    		(unsigned long)memblock.memory.total_size >> 20);
    	os_info_crashkernel_add(crash_base, crash_size);
    #endif
    }
    
    /*
     * Reserve the initrd from being used by memblock
     */
    static void __init reserve_initrd(void)
    {
    #ifdef CONFIG_BLK_DEV_INITRD
    	if (!initrd_data.start || !initrd_data.size)
    		return;
    	initrd_start = (unsigned long)__va(initrd_data.start);
    	initrd_end = initrd_start + initrd_data.size;
    	memblock_reserve(initrd_data.start, initrd_data.size);
    #endif
    }
    
    /*
     * Reserve the memory area used to pass the certificate lists
     */
    static void __init reserve_certificate_list(void)
    {
    	if (ipl_cert_list_addr)
    		memblock_reserve(ipl_cert_list_addr, ipl_cert_list_size);
    }
    
    static void __init reserve_mem_detect_info(void)
    {
    	unsigned long start, size;
    
    	get_mem_detect_reserved(&start, &size);
    	if (size)
    		memblock_reserve(start, size);
    }
    
    static void __init free_mem_detect_info(void)
    {
    	unsigned long start, size;
    
    	get_mem_detect_reserved(&start, &size);
    	if (size)
    		memblock_phys_free(start, size);
    }
    
    static const char * __init get_mem_info_source(void)
    {
    	switch (mem_detect.info_source) {
    	case MEM_DETECT_SCLP_STOR_INFO:
    		return "sclp storage info";
    	case MEM_DETECT_DIAG260:
    		return "diag260";
    	case MEM_DETECT_SCLP_READ_INFO:
    		return "sclp read info";
    	case MEM_DETECT_BIN_SEARCH:
    		return "binary search";
    	}
    	return "none";
    }
    
    static void __init memblock_add_mem_detect_info(void)
    {
    	unsigned long start, end;
    	int i;
    
    	pr_debug("physmem info source: %s (%hhd)\n",
    		 get_mem_info_source(), mem_detect.info_source);
    	/* keep memblock lists close to the kernel */
    	memblock_set_bottom_up(true);
    	for_each_mem_detect_block(i, &start, &end) {
    		memblock_add(start, end - start);
    		memblock_physmem_add(start, end - start);
    	}
    	memblock_set_bottom_up(false);
    	memblock_set_node(0, ULONG_MAX, &memblock.memory, 0);
    }
    
    /*
     * Check for initrd being in usable memory
     */
    static void __init check_initrd(void)
    {
    #ifdef CONFIG_BLK_DEV_INITRD
    	if (initrd_data.start && initrd_data.size &&
    	    !memblock_is_region_memory(initrd_data.start, initrd_data.size)) {
    		pr_err("The initial RAM disk does not fit into the memory\n");
    		memblock_phys_free(initrd_data.start, initrd_data.size);
    		initrd_start = initrd_end = 0;
    	}
    #endif
    }
    
    /*
     * Reserve memory used for lowcore/command line/kernel image.
     */
    static void __init reserve_kernel(void)
    {
    	memblock_reserve(0, STARTUP_NORMAL_OFFSET);
    	memblock_reserve(OLDMEM_BASE, sizeof(unsigned long));
    	memblock_reserve(OLDMEM_SIZE, sizeof(unsigned long));
    	memblock_reserve(__amode31_base, __eamode31 - __samode31);
    	memblock_reserve(__pa(sclp_early_sccb), EXT_SCCB_READ_SCP);
    	memblock_reserve(__pa(_stext), _end - _stext);
    }
    
    static void __init setup_memory(void)
    {
    	phys_addr_t start, end;
    	u64 i;
    
    	/*
    	 * Init storage key for present memory
    	 */
    	for_each_mem_range(i, &start, &end)
    		storage_key_init_range(start, end);
    
    	psw_set_key(PAGE_DEFAULT_KEY);
    }
    
    static void __init relocate_amode31_section(void)
    {
    	unsigned long amode31_size = __eamode31 - __samode31;
    	long amode31_offset = __amode31_base - __samode31;
    	long *ptr;
    
    	pr_info("Relocating AMODE31 section of size 0x%08lx\n", amode31_size);
    
    	/* Move original AMODE31 section to the new one */
    	memmove((void *)__amode31_base, (void *)__samode31, amode31_size);
    	/* Zero out the old AMODE31 section to catch invalid accesses within it */
    	memset((void *)__samode31, 0, amode31_size);
    
    	/* Update all AMODE31 region references */
    	for (ptr = _start_amode31_refs; ptr != _end_amode31_refs; ptr++)
    		*ptr += amode31_offset;
    }
    
    /* This must be called after AMODE31 relocation */
    static void __init setup_cr(void)
    {
    	union ctlreg2 cr2;
    	union ctlreg5 cr5;
    	union ctlreg15 cr15;
    
    	__ctl_duct[1] = (unsigned long)__ctl_aste;
    	__ctl_duct[2] = (unsigned long)__ctl_aste;
    	__ctl_duct[4] = (unsigned long)__ctl_duald;
    
    	/* Update control registers CR2, CR5 and CR15 */
    	__ctl_store(cr2.val, 2, 2);
    	__ctl_store(cr5.val, 5, 5);
    	__ctl_store(cr15.val, 15, 15);
    	cr2.ducto = (unsigned long)__ctl_duct >> 6;
    	cr5.pasteo = (unsigned long)__ctl_duct >> 6;
    	cr15.lsea = (unsigned long)__ctl_linkage_stack >> 3;
    	__ctl_load(cr2.val, 2, 2);
    	__ctl_load(cr5.val, 5, 5);
    	__ctl_load(cr15.val, 15, 15);
    }
    
    /*
     * Add system information as device randomness
     */
    static void __init setup_randomness(void)
    {
    	struct sysinfo_3_2_2 *vmms;
    
    	vmms = memblock_alloc(PAGE_SIZE, PAGE_SIZE);
    	if (!vmms)
    		panic("Failed to allocate memory for sysinfo structure\n");
    	if (stsi(vmms, 3, 2, 2) == 0 && vmms->count)
    		add_device_randomness(&vmms->vm, sizeof(vmms->vm[0]) * vmms->count);
    	memblock_free(vmms, PAGE_SIZE);
    }
    
    /*
     * Find the correct size for the task_struct. This depends on
     * the size of the struct fpu at the end of the thread_struct
     * which is embedded in the task_struct.
     */
    static void __init setup_task_size(void)
    {
    	int task_size = sizeof(struct task_struct);
    
    	if (!MACHINE_HAS_VX) {
    		task_size -= sizeof(__vector128) * __NUM_VXRS;
    		task_size += sizeof(freg_t) * __NUM_FPRS;
    	}
    	arch_task_struct_size = task_size;
    }
    
    /*
     * Issue diagnose 318 to set the control program name and
     * version codes.
     */
    static void __init setup_control_program_code(void)
    {
    	union diag318_info diag318_info = {
    		.cpnc = CPNC_LINUX,
    		.cpvc = 0,
    	};
    
    	if (!sclp.has_diag318)
    		return;
    
    	diag_stat_inc(DIAG_STAT_X318);
    	asm volatile("diag %0,0,0x318\n" : : "d" (diag318_info.val));
    }
    
    /*
     * Print the component list from the IPL report
     */
    static void __init log_component_list(void)
    {
    	struct ipl_rb_component_entry *ptr, *end;
    	char *str;
    
    	if (!early_ipl_comp_list_addr)
    		return;
    	if (ipl_block.hdr.flags & IPL_PL_FLAG_SIPL)
    		pr_info("Linux is running with Secure-IPL enabled\n");
    	else
    		pr_info("Linux is running with Secure-IPL disabled\n");
    	ptr = (void *) early_ipl_comp_list_addr;
    	end = (void *) ptr + early_ipl_comp_list_size;
    	pr_info("The IPL report contains the following components:\n");
    	while (ptr < end) {
    		if (ptr->flags & IPL_RB_COMPONENT_FLAG_SIGNED) {
    			if (ptr->flags & IPL_RB_COMPONENT_FLAG_VERIFIED)
    				str = "signed, verified";
    			else
    				str = "signed, verification failed";
    		} else {
    			str = "not signed";
    		}
    		pr_info("%016llx - %016llx (%s)\n",
    			ptr->addr, ptr->addr + ptr->len, str);
    		ptr++;
    	}
    }
    
    /*
     * Setup function called from init/main.c just after the banner
     * was printed.
     */
    
    void __init setup_arch(char **cmdline_p)
    {
            /*
             * print what head.S has found out about the machine
             */
    	if (MACHINE_IS_VM)
    		pr_info("Linux is running as a z/VM "
    			"guest operating system in 64-bit mode\n");
    	else if (MACHINE_IS_KVM)
    		pr_info("Linux is running under KVM in 64-bit mode\n");
    	else if (MACHINE_IS_LPAR)
    		pr_info("Linux is running natively in 64-bit mode\n");
    	else
    		pr_info("Linux is running as a guest in 64-bit mode\n");
    
    	log_component_list();
    
    	/* Have one command line that is parsed and saved in /proc/cmdline */
    	/* boot_command_line has been already set up in early.c */
    	*cmdline_p = boot_command_line;
    
            ROOT_DEV = Root_RAM0;
    
    	setup_initial_init_mm(_text, _etext, _edata, _end);
    
    	if (IS_ENABLED(CONFIG_EXPOLINE_AUTO))
    		nospec_auto_detect();
    
    	jump_label_init();
    	parse_early_param();
    #ifdef CONFIG_CRASH_DUMP
    	/* Deactivate elfcorehdr= kernel parameter */
    	elfcorehdr_addr = ELFCORE_ADDR_MAX;
    #endif
    
    	os_info_init();
    	setup_ipl();
    	setup_task_size();
    	setup_control_program_code();
    
    	/* Do some memory reservations *before* memory is added to memblock */
    	reserve_kernel();
    	reserve_initrd();
    	reserve_certificate_list();
    	reserve_mem_detect_info();
    	memblock_set_current_limit(ident_map_size);
    	memblock_allow_resize();
    
    	/* Get information about *all* installed memory */
    	memblock_add_mem_detect_info();
    
    	free_mem_detect_info();
    	setup_memory_end();
    	memblock_dump_all();
    	setup_memory();
    
    	relocate_amode31_section();
    	setup_cr();
    	setup_uv();
    	dma_contiguous_reserve(ident_map_size);
    	vmcp_cma_reserve();
    	if (MACHINE_HAS_EDAT2)
    		hugetlb_cma_reserve(PUD_SHIFT - PAGE_SHIFT);
    
    	check_initrd();
    	reserve_crashkernel();
    #ifdef CONFIG_CRASH_DUMP
    	/*
    	 * Be aware that smp_save_dump_cpus() triggers a system reset.
    	 * Therefore CPU and device initialization should be done afterwards.
    	 */
    	smp_save_dump_cpus();
    #endif
    
    	setup_resources();
    	setup_lowcore_dat_off();
    	smp_fill_possible_mask();
    	cpu_detect_mhz_feature();
            cpu_init();
    	numa_setup();
    	smp_detect_cpus();
    	topology_init_early();
    
    	if (test_facility(193))
    		static_branch_enable(&cpu_has_bear);
    
    	/*
    	 * Create kernel page tables and switch to virtual addressing.
    	 */
            paging_init();
    
    	/*
    	 * After paging_init created the kernel page table, the new PSWs
    	 * in lowcore can now run with DAT enabled.
    	 */
    	setup_lowcore_dat_on();
    
            /* Setup default console */
    	conmode_default();
    	set_preferred_console();
    
    	apply_alternative_instructions();
    	if (IS_ENABLED(CONFIG_EXPOLINE))
    		nospec_init_branches();
    
    	/* Setup zfcp/nvme dump support */
    	setup_zfcpdump();
    
    	/* Add system specific data to the random pool */
    	setup_randomness();
    }