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/*
* arch/s390/kernel/machine_kexec.c
*
* Copyright IBM Corp. 2005,2011
*
* Author(s): Rolf Adelsberger,
* Heiko Carstens <heiko.carstens@de.ibm.com>
* Michael Holzheu <holzheu@linux.vnet.ibm.com>
*/
#include <linux/device.h>
#include <linux/mm.h>
#include <linux/kexec.h>
#include <linux/delay.h>
#include <linux/reboot.h>
#include <linux/ftrace.h>
#include <asm/cio.h>
#include <asm/setup.h>
#include <asm/pgtable.h>
#include <asm/pgalloc.h>
#include <asm/system.h>
#include <asm/smp.h>
#include <asm/reset.h>
#include <asm/ipl.h>
#include <asm/diag.h>
#include <asm/asm-offsets.h>
typedef void (*relocate_kernel_t)(kimage_entry_t *, unsigned long);
extern const unsigned char relocate_kernel[];
extern const unsigned long long relocate_kernel_len;
#ifdef CONFIG_CRASH_DUMP
void *fill_cpu_elf_notes(void *ptr, struct save_area *sa);
/*
* Create ELF notes for one CPU
*/
static void add_elf_notes(int cpu)
{
struct save_area *sa = (void *) 4608 + store_prefix();
void *ptr;
memcpy((void *) (4608UL + sa->pref_reg), sa, sizeof(*sa));
ptr = (u64 *) per_cpu_ptr(crash_notes, cpu);
ptr = fill_cpu_elf_notes(ptr, sa);
memset(ptr, 0, sizeof(struct elf_note));
}
/*
* Initialize CPU ELF notes
*/
void setup_regs(void)
{
unsigned long sa = S390_lowcore.prefixreg_save_area + SAVE_AREA_BASE;
int cpu, this_cpu;
this_cpu = smp_find_processor_id(stap());
add_elf_notes(this_cpu);
for_each_online_cpu(cpu) {
if (cpu == this_cpu)
continue;
if (smp_store_status(cpu))
continue;
add_elf_notes(cpu);
}
/* Copy dump CPU store status info to absolute zero */
memcpy((void *) SAVE_AREA_BASE, (void *) sa, sizeof(struct save_area));
}
#endif
/*
* Start kdump: We expect here that a store status has been done on our CPU
*/
static void __do_machine_kdump(void *image)
{
#ifdef CONFIG_CRASH_DUMP
int (*start_kdump)(int) = (void *)((struct kimage *) image)->start;
__load_psw_mask(PSW_MASK_BASE | PSW_DEFAULT_KEY | PSW_MASK_EA | PSW_MASK_BA);
setup_regs();
start_kdump(1);
#endif
}
/*
* Check if kdump checksums are valid: We call purgatory with parameter "0"
*/
static int kdump_csum_valid(struct kimage *image)
{
#ifdef CONFIG_CRASH_DUMP
int (*start_kdump)(int) = (void *)image->start;
int rc;
__arch_local_irq_stnsm(0xfb); /* disable DAT */
rc = start_kdump(0);
__arch_local_irq_stosm(0x04); /* enable DAT */
return rc ? 0 : -EINVAL;
#else
return -EINVAL;
#endif
}
/*
* Map or unmap crashkernel memory
*/
static void crash_map_pages(int enable)
{
unsigned long size = resource_size(&crashk_res);
BUG_ON(crashk_res.start % KEXEC_CRASH_MEM_ALIGN ||
size % KEXEC_CRASH_MEM_ALIGN);
if (enable)
vmem_add_mapping(crashk_res.start, size);
else
vmem_remove_mapping(crashk_res.start, size);
}
/*
* Map crashkernel memory
*/
void crash_map_reserved_pages(void)
{
crash_map_pages(1);
}
/*
* Unmap crashkernel memory
*/
void crash_unmap_reserved_pages(void)
{
crash_map_pages(0);
}
/*
* Give back memory to hypervisor before new kdump is loaded
*/
static int machine_kexec_prepare_kdump(void)
{
#ifdef CONFIG_CRASH_DUMP
if (MACHINE_IS_VM)
diag10_range(PFN_DOWN(crashk_res.start),
PFN_DOWN(crashk_res.end - crashk_res.start + 1));
return 0;
#else
return -EINVAL;
#endif
}
int machine_kexec_prepare(struct kimage *image)
{
void *reboot_code_buffer;
/* Can't replace kernel image since it is read-only. */
if (ipl_flags & IPL_NSS_VALID)
return -ENOSYS;
if (image->type == KEXEC_TYPE_CRASH)
return machine_kexec_prepare_kdump();
/* We don't support anything but the default image type for now. */
if (image->type != KEXEC_TYPE_DEFAULT)
return -EINVAL;
/* Get the destination where the assembler code should be copied to.*/
reboot_code_buffer = (void *) page_to_phys(image->control_code_page);
/* Then copy it */
memcpy(reboot_code_buffer, relocate_kernel, relocate_kernel_len);
return 0;
}
void machine_kexec_cleanup(struct kimage *image)
{
}
void arch_crash_save_vmcoreinfo(void)
{
VMCOREINFO_SYMBOL(lowcore_ptr);
VMCOREINFO_SYMBOL(high_memory);
VMCOREINFO_LENGTH(lowcore_ptr, NR_CPUS);
}
void machine_shutdown(void)
{
}
/*
* Do normal kexec
*/
static void __do_machine_kexec(void *data)
{
relocate_kernel_t data_mover;
struct kimage *image = data;
data_mover = (relocate_kernel_t) page_to_phys(image->control_code_page);
/* Call the moving routine */
(*data_mover)(&image->head, image->start);
}
/*
* Reset system and call either kdump or normal kexec
*/
static void __machine_kexec(void *data)
{
struct kimage *image = data;
pfault_fini();
if (image->type == KEXEC_TYPE_CRASH)
s390_reset_system(__do_machine_kdump, data);
else
s390_reset_system(__do_machine_kexec, data);
disabled_wait((unsigned long) __builtin_return_address(0));
}
/*
* Do either kdump or normal kexec. In case of kdump we first ask
* purgatory, if kdump checksums are valid.
*/
void machine_kexec(struct kimage *image)
{
if (image->type == KEXEC_TYPE_CRASH && !kdump_csum_valid(image))
return;
tracer_disable();
smp_send_stop();
smp_call_ipl_cpu(__machine_kexec, image);
}
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