2
0
mirror of https://github.com/edk2-porting/linux-next.git synced 2024-12-24 21:24:00 +08:00
linux-next/arch/s390/kernel/machine_kexec.c
Xunlei Pang 7a0058ec78 s390/kexec: consolidate crash_map/unmap_reserved_pages() and arch_kexec_protect(unprotect)_crashkres()
Commit 3f625002581b ("kexec: introduce a protection mechanism for the
crashkernel reserved memory") is a similar mechanism for protecting the
crash kernel reserved memory to previous crash_map/unmap_reserved_pages()
implementation, the new one is more generic in name and cleaner in code
(besides, some arch may not be allowed to unmap the pgtable).

Therefore, this patch consolidates them, and uses the new
arch_kexec_protect(unprotect)_crashkres() to replace former
crash_map/unmap_reserved_pages() which by now has been only used by
S390.

The consolidation work needs the crash memory to be mapped initially,
this is done in machine_kdump_pm_init() which is after
reserve_crashkernel().  Once kdump kernel is loaded, the new
arch_kexec_protect_crashkres() implemented for S390 will actually
unmap the pgtable like before.

Signed-off-by: Xunlei Pang <xlpang@redhat.com>
Signed-off-by: Michael Holzheu <holzheu@linux.vnet.ibm.com>
Acked-by: Michael Holzheu <holzheu@linux.vnet.ibm.com>
Cc: Heiko Carstens <heiko.carstens@de.ibm.com>
Cc: "Eric W. Biederman" <ebiederm@xmission.com>
Cc: Minfei Huang <mhuang@redhat.com>
Cc: Vivek Goyal <vgoyal@redhat.com>
Cc: Dave Young <dyoung@redhat.com>
Cc: Baoquan He <bhe@redhat.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2016-05-23 17:04:14 -07:00

296 lines
6.7 KiB
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 <linux/debug_locks.h>
#include <linux/suspend.h>
#include <asm/cio.h>
#include <asm/setup.h>
#include <asm/pgtable.h>
#include <asm/pgalloc.h>
#include <asm/smp.h>
#include <asm/reset.h>
#include <asm/ipl.h>
#include <asm/diag.h>
#include <asm/elf.h>
#include <asm/asm-offsets.h>
#include <asm/os_info.h>
#include <asm/switch_to.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
/*
* PM notifier callback for kdump
*/
static int machine_kdump_pm_cb(struct notifier_block *nb, unsigned long action,
void *ptr)
{
switch (action) {
case PM_SUSPEND_PREPARE:
case PM_HIBERNATION_PREPARE:
if (kexec_crash_image)
arch_kexec_unprotect_crashkres();
break;
case PM_POST_SUSPEND:
case PM_POST_HIBERNATION:
if (kexec_crash_image)
arch_kexec_protect_crashkres();
break;
default:
return NOTIFY_DONE;
}
return NOTIFY_OK;
}
static int __init machine_kdump_pm_init(void)
{
pm_notifier(machine_kdump_pm_cb, 0);
/* Create initial mapping for crashkernel memory */
arch_kexec_unprotect_crashkres();
return 0;
}
arch_initcall(machine_kdump_pm_init);
/*
* Reset the system, copy boot CPU registers to absolute zero,
* and jump to the kdump image
*/
static void __do_machine_kdump(void *image)
{
int (*start_kdump)(int);
unsigned long prefix;
/* 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((void *) __LC_FPREGS_SAVE_AREA,
(void *)(prefix + __LC_FPREGS_SAVE_AREA), 512);
__load_psw_mask(PSW_MASK_BASE | PSW_DEFAULT_KEY | PSW_MASK_EA | PSW_MASK_BA);
start_kdump = (void *)((struct kimage *) image)->start;
start_kdump(1);
/* Die if start_kdump returns */
disabled_wait((unsigned long) __builtin_return_address(0));
}
/*
* 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)
{
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 */
if (MACHINE_HAS_VX)
save_vx_regs((void *) &S390_lowcore.vector_save_area);
/*
* 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
/*
* 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
}
#ifdef CONFIG_CRASH_DUMP
/*
* 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);
if (size)
os_info_crashkernel_add(crashk_res.start, size);
else
os_info_crashkernel_add(0, 0);
}
}
/*
* Unmap crashkernel memory
*/
void arch_kexec_protect_crashkres(void)
{
if (crashk_res.end)
crash_map_pages(0);
}
/*
* Map crashkernel memory
*/
void arch_kexec_unprotect_crashkres(void)
{
if (crashk_res.end)
crash_map_pages(1);
}
#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;
/* Can't replace kernel image since it is read-only. */
if (ipl_flags & IPL_NSS_VALID)
return -EOPNOTSUPP;
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)
{
}
void machine_crash_shutdown(struct pt_regs *regs)
{
}
/*
* Do normal kexec
*/
static void __do_machine_kexec(void *data)
{
relocate_kernel_t data_mover;
struct kimage *image = data;
s390_reset_system();
data_mover = (relocate_kernel_t) page_to_phys(image->control_code_page);
/* Call the moving routine */
(*data_mover)(&image->head, image->start);
/* Die if kexec returns */
disabled_wait((unsigned long) __builtin_return_address(0));
}
/*
* Reset system and call either kdump or normal kexec
*/
static void __machine_kexec(void *data)
{
__arch_local_irq_stosm(0x04); /* enable DAT */
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);
}