forked from Minki/linux
1a36a39e22
To collect the CPU registers of the crashed system allocated a single page with memblock_alloc_base and use it as a copy buffer. Replace the stop-and-store-status sigp with a store-status-at-address sigp in smp_save_dump_cpus() and smp_store_status(). In both cases the target CPU is already stopped and store-status-at-address avoids the detour via the absolute zero page. For kexec simplify s390_reset_system and call store_status() before the prefix register of the boot CPU has been set to zero. Use STPX to store the prefix register and remove dump_prefix_page. Acked-by: Michael Holzheu <holzheu@linux.vnet.ibm.com> Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
288 lines
6.5 KiB
C
288 lines
6.5 KiB
C
/*
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* Copyright IBM Corp. 2005, 2011
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*
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* Author(s): Rolf Adelsberger,
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* Heiko Carstens <heiko.carstens@de.ibm.com>
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* Michael Holzheu <holzheu@linux.vnet.ibm.com>
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*/
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#include <linux/device.h>
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#include <linux/mm.h>
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#include <linux/kexec.h>
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#include <linux/delay.h>
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#include <linux/reboot.h>
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#include <linux/ftrace.h>
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#include <linux/debug_locks.h>
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#include <linux/suspend.h>
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#include <asm/cio.h>
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#include <asm/setup.h>
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#include <asm/pgtable.h>
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#include <asm/pgalloc.h>
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#include <asm/smp.h>
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#include <asm/reset.h>
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#include <asm/ipl.h>
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#include <asm/diag.h>
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#include <asm/elf.h>
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#include <asm/asm-offsets.h>
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#include <asm/os_info.h>
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#include <asm/switch_to.h>
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typedef void (*relocate_kernel_t)(kimage_entry_t *, unsigned long);
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extern const unsigned char relocate_kernel[];
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extern const unsigned long long relocate_kernel_len;
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#ifdef CONFIG_CRASH_DUMP
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/*
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* PM notifier callback for kdump
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*/
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static int machine_kdump_pm_cb(struct notifier_block *nb, unsigned long action,
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void *ptr)
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{
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switch (action) {
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case PM_SUSPEND_PREPARE:
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case PM_HIBERNATION_PREPARE:
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if (crashk_res.start)
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crash_map_reserved_pages();
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break;
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case PM_POST_SUSPEND:
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case PM_POST_HIBERNATION:
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if (crashk_res.start)
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crash_unmap_reserved_pages();
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break;
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default:
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return NOTIFY_DONE;
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}
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return NOTIFY_OK;
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}
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static int __init machine_kdump_pm_init(void)
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{
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pm_notifier(machine_kdump_pm_cb, 0);
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return 0;
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}
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arch_initcall(machine_kdump_pm_init);
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/*
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* Reset the system, copy boot CPU registers to absolute zero,
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* and jump to the kdump image
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*/
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static void __do_machine_kdump(void *image)
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{
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int (*start_kdump)(int);
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unsigned long prefix;
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/* store_status() saved the prefix register to lowcore */
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prefix = (unsigned long) S390_lowcore.prefixreg_save_area;
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/* Now do the reset */
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s390_reset_system();
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/*
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* Copy dump CPU store status info to absolute zero.
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* This need to be done *after* s390_reset_system set the
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* prefix register of this CPU to zero
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*/
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memcpy((void *) __LC_FPREGS_SAVE_AREA,
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(void *)(prefix + __LC_FPREGS_SAVE_AREA), 512);
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__load_psw_mask(PSW_MASK_BASE | PSW_DEFAULT_KEY | PSW_MASK_EA | PSW_MASK_BA);
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start_kdump = (void *)((struct kimage *) image)->start;
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start_kdump(1);
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/* Die if start_kdump returns */
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disabled_wait((unsigned long) __builtin_return_address(0));
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}
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/*
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* Start kdump: create a LGR log entry, store status of all CPUs and
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* branch to __do_machine_kdump.
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*/
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static noinline void __machine_kdump(void *image)
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{
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int this_cpu, cpu;
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lgr_info_log();
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/* Get status of the other CPUs */
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this_cpu = smp_find_processor_id(stap());
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for_each_online_cpu(cpu) {
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if (cpu == this_cpu)
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continue;
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if (smp_store_status(cpu))
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continue;
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}
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/* Store status of the boot CPU */
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if (MACHINE_HAS_VX)
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save_vx_regs((void *) &S390_lowcore.vector_save_area);
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/*
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* To create a good backchain for this CPU in the dump store_status
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* is passed the address of a function. The address is saved into
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* the PSW save area of the boot CPU and the function is invoked as
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* a tail call of store_status. The backchain in the dump will look
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* like this:
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* restart_int_handler -> __machine_kexec -> __do_machine_kdump
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* The call to store_status() will not return.
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*/
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store_status(__do_machine_kdump, image);
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}
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#endif
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/*
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* Check if kdump checksums are valid: We call purgatory with parameter "0"
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*/
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static int kdump_csum_valid(struct kimage *image)
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{
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#ifdef CONFIG_CRASH_DUMP
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int (*start_kdump)(int) = (void *)image->start;
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int rc;
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__arch_local_irq_stnsm(0xfb); /* disable DAT */
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rc = start_kdump(0);
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__arch_local_irq_stosm(0x04); /* enable DAT */
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return rc ? 0 : -EINVAL;
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#else
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return -EINVAL;
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#endif
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}
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/*
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* Map or unmap crashkernel memory
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*/
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static void crash_map_pages(int enable)
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{
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unsigned long size = resource_size(&crashk_res);
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BUG_ON(crashk_res.start % KEXEC_CRASH_MEM_ALIGN ||
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size % KEXEC_CRASH_MEM_ALIGN);
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if (enable)
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vmem_add_mapping(crashk_res.start, size);
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else {
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vmem_remove_mapping(crashk_res.start, size);
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if (size)
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os_info_crashkernel_add(crashk_res.start, size);
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else
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os_info_crashkernel_add(0, 0);
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}
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}
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/*
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* Map crashkernel memory
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*/
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void crash_map_reserved_pages(void)
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{
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crash_map_pages(1);
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}
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/*
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* Unmap crashkernel memory
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*/
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void crash_unmap_reserved_pages(void)
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{
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crash_map_pages(0);
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}
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/*
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* Give back memory to hypervisor before new kdump is loaded
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*/
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static int machine_kexec_prepare_kdump(void)
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{
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#ifdef CONFIG_CRASH_DUMP
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if (MACHINE_IS_VM)
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diag10_range(PFN_DOWN(crashk_res.start),
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PFN_DOWN(crashk_res.end - crashk_res.start + 1));
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return 0;
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#else
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return -EINVAL;
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#endif
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}
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int machine_kexec_prepare(struct kimage *image)
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{
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void *reboot_code_buffer;
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/* Can't replace kernel image since it is read-only. */
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if (ipl_flags & IPL_NSS_VALID)
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return -EOPNOTSUPP;
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if (image->type == KEXEC_TYPE_CRASH)
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return machine_kexec_prepare_kdump();
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/* We don't support anything but the default image type for now. */
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if (image->type != KEXEC_TYPE_DEFAULT)
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return -EINVAL;
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/* Get the destination where the assembler code should be copied to.*/
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reboot_code_buffer = (void *) page_to_phys(image->control_code_page);
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/* Then copy it */
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memcpy(reboot_code_buffer, relocate_kernel, relocate_kernel_len);
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return 0;
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}
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void machine_kexec_cleanup(struct kimage *image)
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{
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}
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void arch_crash_save_vmcoreinfo(void)
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{
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VMCOREINFO_SYMBOL(lowcore_ptr);
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VMCOREINFO_SYMBOL(high_memory);
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VMCOREINFO_LENGTH(lowcore_ptr, NR_CPUS);
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}
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void machine_shutdown(void)
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{
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}
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void machine_crash_shutdown(struct pt_regs *regs)
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{
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}
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/*
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* Do normal kexec
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*/
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static void __do_machine_kexec(void *data)
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{
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relocate_kernel_t data_mover;
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struct kimage *image = data;
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s390_reset_system();
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data_mover = (relocate_kernel_t) page_to_phys(image->control_code_page);
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/* Call the moving routine */
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(*data_mover)(&image->head, image->start);
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/* Die if kexec returns */
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disabled_wait((unsigned long) __builtin_return_address(0));
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}
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/*
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* Reset system and call either kdump or normal kexec
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*/
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static void __machine_kexec(void *data)
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{
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__arch_local_irq_stosm(0x04); /* enable DAT */
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pfault_fini();
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tracing_off();
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debug_locks_off();
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#ifdef CONFIG_CRASH_DUMP
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if (((struct kimage *) data)->type == KEXEC_TYPE_CRASH)
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__machine_kdump(data);
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#endif
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__do_machine_kexec(data);
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}
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/*
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* Do either kdump or normal kexec. In case of kdump we first ask
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* purgatory, if kdump checksums are valid.
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*/
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void machine_kexec(struct kimage *image)
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{
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if (image->type == KEXEC_TYPE_CRASH && !kdump_csum_valid(image))
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return;
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tracer_disable();
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smp_send_stop();
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smp_call_ipl_cpu(__machine_kexec, image);
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}
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