kernel-fxtec-pro1x/arch/s390/kernel/machine_kexec.c
Martin Schwidefsky 10ad34bc76 s390: add SMT support
The multi-threading facility is introduced with the z13 processor family.
This patch adds code to detect the multi-threading facility. With the
facility enabled each core will surface multiple hardware threads to the
system. Each hardware threads looks like a normal CPU to the operating
system with all its registers and properties.

The SCLP interface reports the SMT topology indirectly via the maximum
thread id. Each reported CPU in the result of a read-scp-information
is a core representing a number of hardware threads.

To reflect the reduced CPU capacity if two hardware threads run on a
single core the MT utilization counter set is used to normalize the
raw cputime obtained by the CPU timer deltas. This scaled cputime is
reported via the taskstats interface. The normal /proc/stat numbers
are based on the raw cputime and are not affected by the normalization.

Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
2015-01-22 12:16:01 +01:00

275 lines
6.1 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
/*
* 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, NULL);
memset(ptr, 0, sizeof(struct elf_note));
}
/*
* Initialize CPU ELF notes
*/
static void setup_regs(void)
{
unsigned long sa = S390_lowcore.prefixreg_save_area + SAVE_AREA_BASE;
struct _lowcore *lc;
int cpu, this_cpu;
/* Get lowcore pointer from store status of this CPU (absolute zero) */
lc = (struct _lowcore *)(unsigned long)S390_lowcore.prefixreg_save_area;
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);
}
if (MACHINE_HAS_VX)
save_vx_regs_safe((void *) lc->vector_save_area_addr);
/* Copy dump CPU store status info to absolute zero */
memcpy((void *) SAVE_AREA_BASE, (void *) sa, sizeof(struct save_area));
}
/*
* 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 (crashk_res.start)
crash_map_reserved_pages();
break;
case PM_POST_SUSPEND:
case PM_POST_HIBERNATION:
if (crashk_res.start)
crash_unmap_reserved_pages();
break;
default:
return NOTIFY_DONE;
}
return NOTIFY_OK;
}
static int __init machine_kdump_pm_init(void)
{
pm_notifier(machine_kdump_pm_cb, 0);
return 0;
}
arch_initcall(machine_kdump_pm_init);
/*
* Start kdump: We expect here that a store status has been done on our CPU
*/
static void __do_machine_kdump(void *image)
{
int (*start_kdump)(int) = (void *)((struct kimage *) image)->start;
__load_psw_mask(PSW_MASK_BASE | PSW_DEFAULT_KEY | PSW_MASK_EA | PSW_MASK_BA);
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);
if (size)
os_info_crashkernel_add(crashk_res.start, size);
else
os_info_crashkernel_add(0, 0);
}
}
/*
* 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 -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;
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)
{
__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) {
lgr_info_log();
s390_reset_system(setup_regs, __do_machine_kdump, data);
} else
#endif
s390_reset_system(NULL, __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);
}