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// SPDX-License-Identifier: GPL-2.0
/*
* Copyright IBM Corp. 2005, 2011
*
* Author(s): Rolf Adelsberger,
* 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 <linux/debug_locks.h>
#include <asm/pfault.h>
#include <asm/cio.h>
#include <asm/setup.h>
#include <asm/smp.h>
#include <asm/ipl.h>
#include <asm/diag.h>
#include <asm/elf.h>
#include <asm/asm-offsets.h>
#include <asm/cacheflush.h>
#include <asm/abs_lowcore.h>
#include <asm/os_info.h>
#include <asm/set_memory.h>
#include <asm/stacktrace.h>
#include <asm/switch_to.h>
#include <asm/nmi.h>
#include <asm/sclp.h>
typedef void (*relocate_kernel_t)(unsigned long, unsigned long, unsigned long);
typedef int (*purgatory_t)(int);
extern const unsigned char relocate_kernel[];
extern const unsigned long long relocate_kernel_len;
#ifdef CONFIG_CRASH_DUMP
/*
* Reset the system, copy boot CPU registers to absolute zero,
* and jump to the kdump image
*/
static void __do_machine_kdump(void *data)
{
struct kimage *image = data;
purgatory_t purgatory;
unsigned long prefix;
purgatory = (purgatory_t)image->start;
/* store_status() saved the prefix register to lowcore */
prefix = (unsigned long) S390_lowcore.prefixreg_save_area;
/* Now do the reset */
s390_reset_system();
/*
* Copy dump CPU store status info to absolute zero.
* This need to be done *after* s390_reset_system set the
* prefix register of this CPU to zero
*/
memcpy(absolute_pointer(__LC_FPREGS_SAVE_AREA),
phys_to_virt(prefix + __LC_FPREGS_SAVE_AREA), 512);
call_nodat(1, int, purgatory, int, 1);
/* Die if kdump returns */
disabled_wait();
}
/*
* Start kdump: create a LGR log entry, store status of all CPUs and
* branch to __do_machine_kdump.
*/
static noinline void __machine_kdump(void *image)
{
struct mcesa *mcesa;
union ctlreg2 cr2_old, cr2_new;
int this_cpu, cpu;
lgr_info_log();
/* Get status of the other CPUs */
this_cpu = smp_find_processor_id(stap());
for_each_online_cpu(cpu) {
if (cpu == this_cpu)
continue;
if (smp_store_status(cpu))
continue;
}
/* Store status of the boot CPU */
mcesa = __va(S390_lowcore.mcesad & MCESA_ORIGIN_MASK);
if (cpu_has_vx())
save_vx_regs((__vector128 *) mcesa->vector_save_area);
if (MACHINE_HAS_GS) {
local_ctl_store(2, &cr2_old.reg);
cr2_new = cr2_old;
cr2_new.gse = 1;
local_ctl_load(2, &cr2_new.reg);
save_gs_cb((struct gs_cb *) mcesa->guarded_storage_save_area);
local_ctl_load(2, &cr2_old.reg);
}
/*
* To create a good backchain for this CPU in the dump store_status
* is passed the address of a function. The address is saved into
* the PSW save area of the boot CPU and the function is invoked as
* a tail call of store_status. The backchain in the dump will look
* like this:
* restart_int_handler -> __machine_kexec -> __do_machine_kdump
* The call to store_status() will not return.
*/
store_status(__do_machine_kdump, image);
}
#endif /* CONFIG_CRASH_DUMP */
/*
* Check if kdump checksums are valid: We call purgatory with parameter "0"
*/
static bool kdump_csum_valid(struct kimage *image)
{
#ifdef CONFIG_CRASH_DUMP
purgatory_t purgatory = (purgatory_t)image->start;
int rc;
rc = call_nodat(1, int, purgatory, int, 0);
return rc == 0;
#else
return false;
#endif
}
#ifdef CONFIG_CRASH_DUMP
void crash_free_reserved_phys_range(unsigned long begin, unsigned long end)
{
unsigned long addr, size;
for (addr = begin; addr < end; addr += PAGE_SIZE)
free_reserved_page(pfn_to_page(addr >> PAGE_SHIFT));
size = begin - crashk_res.start;
if (size)
os_info_crashkernel_add(crashk_res.start, size);
else
os_info_crashkernel_add(0, 0);
}
static void crash_protect_pages(int protect)
{
unsigned long size;
if (!crashk_res.end)
return;
size = resource_size(&crashk_res);
if (protect)
set_memory_ro(crashk_res.start, size >> PAGE_SHIFT);
else
set_memory_rw(crashk_res.start, size >> PAGE_SHIFT);
}
void arch_kexec_protect_crashkres(void)
{
crash_protect_pages(1);
}
void arch_kexec_unprotect_crashkres(void)
{
crash_protect_pages(0);
}
#endif
/*
* 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;
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 = page_to_virt(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)
{
struct lowcore *abs_lc;
VMCOREINFO_SYMBOL(lowcore_ptr);
VMCOREINFO_SYMBOL(high_memory);
VMCOREINFO_LENGTH(lowcore_ptr, NR_CPUS);
vmcoreinfo_append_str("SAMODE31=%lx\n", (unsigned long)__samode31);
vmcoreinfo_append_str("EAMODE31=%lx\n", (unsigned long)__eamode31);
vmcoreinfo_append_str("KERNELOFFSET=%lx\n", kaslr_offset());
abs_lc = get_abs_lowcore();
abs_lc->vmcore_info = paddr_vmcoreinfo_note();
put_abs_lowcore(abs_lc);
}
void machine_shutdown(void)
{
}
void machine_crash_shutdown(struct pt_regs *regs)
{
set_os_info_reipl_block();
}
/*
* Do normal kexec
*/
static void __do_machine_kexec(void *data)
{
unsigned long data_mover, entry, diag308_subcode;
struct kimage *image = data;
data_mover = page_to_phys(image->control_code_page);
entry = virt_to_phys(&image->head);
diag308_subcode = DIAG308_CLEAR_RESET;
if (sclp.has_iplcc)
diag308_subcode |= DIAG308_FLAG_EI;
s390_reset_system();
call_nodat(3, void, (relocate_kernel_t)data_mover,
unsigned long, entry,
unsigned long, image->start,
unsigned long, diag308_subcode);
/* Die if kexec returns */
disabled_wait();
}
/*
* Reset system and call either kdump or normal kexec
*/
static void __machine_kexec(void *data)
{
pfault_fini();
tracing_off();
debug_locks_off();
#ifdef CONFIG_CRASH_DUMP
if (((struct kimage *) data)->type == KEXEC_TYPE_CRASH)
__machine_kdump(data);
#endif
__do_machine_kexec(data);
}
/*
* 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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