Release 4.11 arch/s390/kernel/nmi.c
/*
* Machine check handler
*
* Copyright IBM Corp. 2000, 2009
* Author(s): Ingo Adlung <adlung@de.ibm.com>,
* Martin Schwidefsky <schwidefsky@de.ibm.com>,
* Cornelia Huck <cornelia.huck@de.ibm.com>,
* Heiko Carstens <heiko.carstens@de.ibm.com>,
*/
#include <linux/kernel_stat.h>
#include <linux/init.h>
#include <linux/errno.h>
#include <linux/hardirq.h>
#include <linux/time.h>
#include <linux/module.h>
#include <linux/sched/signal.h>
#include <linux/export.h>
#include <asm/lowcore.h>
#include <asm/smp.h>
#include <asm/stp.h>
#include <asm/cputime.h>
#include <asm/nmi.h>
#include <asm/crw.h>
#include <asm/switch_to.h>
#include <asm/ctl_reg.h>
struct mcck_struct {
unsigned int kill_task : 1;
unsigned int channel_report : 1;
unsigned int warning : 1;
unsigned int stp_queue : 1;
unsigned long mcck_code;
};
static DEFINE_PER_CPU(struct mcck_struct, cpu_mcck);
static void s390_handle_damage(void)
{
smp_send_stop();
disabled_wait((unsigned long) __builtin_return_address(0));
while (1);
}
Contributors
| Person | Tokens | Prop | Commits | CommitProp |
| Heiko Carstens | 28 | 100.00% | 2 | 100.00% |
| Total | 28 | 100.00% | 2 | 100.00% |
/*
* Main machine check handler function. Will be called with interrupts enabled
* or disabled and machine checks enabled or disabled.
*/
void s390_handle_mcck(void)
{
unsigned long flags;
struct mcck_struct mcck;
/*
* Disable machine checks and get the current state of accumulated
* machine checks. Afterwards delete the old state and enable machine
* checks again.
*/
local_irq_save(flags);
local_mcck_disable();
mcck = *this_cpu_ptr(&cpu_mcck);
memset(this_cpu_ptr(&cpu_mcck), 0, sizeof(mcck));
clear_cpu_flag(CIF_MCCK_PENDING);
local_mcck_enable();
local_irq_restore(flags);
if (mcck.channel_report)
crw_handle_channel_report();
/*
* A warning may remain for a prolonged period on the bare iron.
* (actually until the machine is powered off, or the problem is gone)
* So we just stop listening for the WARNING MCH and avoid continuously
* being interrupted. One caveat is however, that we must do this per
* processor and cannot use the smp version of ctl_clear_bit().
* On VM we only get one interrupt per virtally presented machinecheck.
* Though one suffices, we may get one interrupt per (virtual) cpu.
*/
if (mcck.warning) { /* WARNING pending ? */
static int mchchk_wng_posted = 0;
/* Use single cpu clear, as we cannot handle smp here. */
__ctl_clear_bit(14, 24); /* Disable WARNING MCH */
if (xchg(&mchchk_wng_posted, 1) == 0)
kill_cad_pid(SIGPWR, 1);
}
if (mcck.stp_queue)
stp_queue_work();
if (mcck.kill_task) {
local_irq_enable();
printk(KERN_EMERG "mcck: Terminating task because of machine "
"malfunction (code 0x%016lx).\n", mcck.mcck_code);
printk(KERN_EMERG "mcck: task: %s, pid: %d.\n",
current->comm, current->pid);
do_exit(SIGSEGV);
}
}
Contributors
| Person | Tokens | Prop | Commits | CommitProp |
| Heiko Carstens | 153 | 92.73% | 5 | 55.56% |
| Sebastian Ott | 7 | 4.24% | 1 | 11.11% |
| Christoph Lameter | 2 | 1.21% | 1 | 11.11% |
| Martin Schwidefsky | 2 | 1.21% | 1 | 11.11% |
| Cédric Le Goater | 1 | 0.61% | 1 | 11.11% |
| Total | 165 | 100.00% | 9 | 100.00% |
EXPORT_SYMBOL_GPL(s390_handle_mcck);
/*
* returns 0 if all registers could be validated
* returns 1 otherwise
*/
static int notrace s390_validate_registers(union mci mci, int umode)
{
int kill_task;
u64 zero;
void *fpt_save_area;
kill_task = 0;
zero = 0;
if (!mci.gr) {
/*
* General purpose registers couldn't be restored and have
* unknown contents. Stop system or terminate process.
*/
if (!umode)
s390_handle_damage();
kill_task = 1;
}
/* Validate control registers */
if (!mci.cr) {
/*
* Control registers have unknown contents.
* Can't recover and therefore stopping machine.
*/
s390_handle_damage();
} else {
asm volatile(
" lctlg 0,15,0(%0)\n"
" ptlb\n"
: : "a" (&S390_lowcore.cregs_save_area) : "memory");
}
if (!mci.fp) {
/*
* Floating point registers can't be restored. If the
* kernel currently uses floating point registers the
* system is stopped. If the process has its floating
* pointer registers loaded it is terminated.
* Otherwise just revalidate the registers.
*/
if (S390_lowcore.fpu_flags & KERNEL_VXR_V0V7)
s390_handle_damage();
if (!test_cpu_flag(CIF_FPU))
kill_task = 1;
}
fpt_save_area = &S390_lowcore.floating_pt_save_area;
if (!mci.fc) {
/*
* Floating point control register can't be restored.
* If the kernel currently uses the floating pointer
* registers and needs the FPC register the system is
* stopped. If the process has its floating pointer
* registers loaded it is terminated. Otherwiese the
* FPC is just revalidated.
*/
if (S390_lowcore.fpu_flags & KERNEL_FPC)
s390_handle_damage();
asm volatile("lfpc %0" : : "Q" (zero));
if (!test_cpu_flag(CIF_FPU))
kill_task = 1;
} else {
asm volatile("lfpc %0"
: : "Q" (S390_lowcore.fpt_creg_save_area));
}
if (!MACHINE_HAS_VX) {
/* Validate floating point registers */
asm volatile(
" ld 0,0(%0)\n"
" ld 1,8(%0)\n"
" ld 2,16(%0)\n"
" ld 3,24(%0)\n"
" ld 4,32(%0)\n"
" ld 5,40(%0)\n"
" ld 6,48(%0)\n"
" ld 7,56(%0)\n"
" ld 8,64(%0)\n"
" ld 9,72(%0)\n"
" ld 10,80(%0)\n"
" ld 11,88(%0)\n"
" ld 12,96(%0)\n"
" ld 13,104(%0)\n"
" ld 14,112(%0)\n"
" ld 15,120(%0)\n"
: : "a" (fpt_save_area) : "memory");
} else {
/* Validate vector registers */
union ctlreg0 cr0;
if (!mci.vr) {
/*
* Vector registers can't be restored. If the kernel
* currently uses vector registers the system is
* stopped. If the process has its vector registers
* loaded it is terminated. Otherwise just revalidate
* the registers.
*/
if (S390_lowcore.fpu_flags & KERNEL_VXR)
s390_handle_damage();
if (!test_cpu_flag(CIF_FPU))
kill_task = 1;
}
cr0.val = S390_lowcore.cregs_save_area[0];
cr0.afp = cr0.vx = 1;
__ctl_load(cr0.val, 0, 0);
asm volatile(
" la 1,%0\n"
" .word 0xe70f,0x1000,0x0036\n" /* vlm 0,15,0(1) */
" .word 0xe70f,0x1100,0x0c36\n" /* vlm 16,31,256(1) */
: : "Q" (*(struct vx_array *)
&S390_lowcore.vector_save_area) : "1");
__ctl_load(S390_lowcore.cregs_save_area[0], 0, 0);
}
/* Validate access registers */
asm volatile(
" lam 0,15,0(%0)"
: : "a" (&S390_lowcore.access_regs_save_area));
if (!mci.ar) {
/*
* Access registers have unknown contents.
* Terminating task.
*/
kill_task = 1;
}
/*
* We don't even try to validate the TOD register, since we simply
* can't write something sensible into that register.
*/
/*
* See if we can validate the TOD programmable register with its
* old contents (should be zero) otherwise set it to zero.
*/
if (!mci.pr)
asm volatile(
" sr 0,0\n"
" sckpf"
: : : "0", "cc");
else
asm volatile(
" l 0,%0\n"
" sckpf"
: : "Q" (S390_lowcore.tod_progreg_save_area)
: "0", "cc");
/* Validate clock comparator register */
set_clock_comparator(S390_lowcore.clock_comparator);
/* Check if old PSW is valid */
if (!mci.wp)
/*
* Can't tell if we come from user or kernel mode
* -> stopping machine.
*/
s390_handle_damage();
if (!mci.ms || !mci.pm || !mci.ia)
kill_task = 1;
return kill_task;
}
Contributors
| Person | Tokens | Prop | Commits | CommitProp |
| Heiko Carstens | 236 | 69.62% | 10 | 71.43% |
| Martin Schwidefsky | 96 | 28.32% | 3 | 21.43% |
| Hendrik Brueckner | 7 | 2.06% | 1 | 7.14% |
| Total | 339 | 100.00% | 14 | 100.00% |
#define MAX_IPD_COUNT 29
#define MAX_IPD_TIME (5 * 60 * USEC_PER_SEC)
/* 5 minutes */
#define ED_STP_ISLAND 6
/* External damage STP island check */
#define ED_STP_SYNC 7
/* External damage STP sync check */
/*
* machine check handler.
*/
void notrace s390_do_machine_check(struct pt_regs *regs)
{
static int ipd_count;
static DEFINE_SPINLOCK(ipd_lock);
static unsigned long long last_ipd;
struct mcck_struct *mcck;
unsigned long long tmp;
union mci mci;
nmi_enter();
inc_irq_stat(NMI_NMI);
mci.val = S390_lowcore.mcck_interruption_code;
mcck = this_cpu_ptr(&cpu_mcck);
if (mci.sd) {
/* System damage -> stopping machine */
s390_handle_damage();
}
if (mci.pd) {
if (mci.b) {
/* Processing backup -> verify if we can survive this */
u64 z_mcic, o_mcic, t_mcic;
z_mcic = (1ULL<<63 | 1ULL<<59 | 1ULL<<29);
o_mcic = (1ULL<<43 | 1ULL<<42 | 1ULL<<41 | 1ULL<<40 |
1ULL<<36 | 1ULL<<35 | 1ULL<<34 | 1ULL<<32 |
1ULL<<30 | 1ULL<<21 | 1ULL<<20 | 1ULL<<17 |
1ULL<<16);
t_mcic = mci.val;
if (((t_mcic & z_mcic) != 0) ||
((t_mcic & o_mcic) != o_mcic)) {
s390_handle_damage();
}
/*
* Nullifying exigent condition, therefore we might
* retry this instruction.
*/
spin_lock(&ipd_lock);
tmp = get_tod_clock();
if (((tmp - last_ipd) >> 12) < MAX_IPD_TIME)
ipd_count++;
else
ipd_count = 1;
last_ipd = tmp;
if (ipd_count == MAX_IPD_COUNT)
s390_handle_damage();
spin_unlock(&ipd_lock);
} else {
/* Processing damage -> stopping machine */
s390_handle_damage();
}
}
if (s390_validate_registers(mci, user_mode(regs))) {
/*
* Couldn't restore all register contents for the
* user space process -> mark task for termination.
*/
mcck->kill_task = 1;
mcck->mcck_code = mci.val;
set_cpu_flag(CIF_MCCK_PENDING);
}
if (mci.cd) {
/* Timing facility damage */
s390_handle_damage();
}
if (mci.ed && mci.ec) {
/* External damage */
if (S390_lowcore.external_damage_code & (1U << ED_STP_SYNC))
mcck->stp_queue |= stp_sync_check();
if (S390_lowcore.external_damage_code & (1U << ED_STP_ISLAND))
mcck->stp_queue |= stp_island_check();
if (mcck->stp_queue)
set_cpu_flag(CIF_MCCK_PENDING);
}
if (mci.se)
/* Storage error uncorrected */
s390_handle_damage();
if (mci.ke)
/* Storage key-error uncorrected */
s390_handle_damage();
if (mci.ds && mci.fa)
/* Storage degradation */
s390_handle_damage();
if (mci.cp) {
/* Channel report word pending */
mcck->channel_report = 1;
set_cpu_flag(CIF_MCCK_PENDING);
}
if (mci.w) {
/* Warning pending */
mcck->warning = 1;
set_cpu_flag(CIF_MCCK_PENDING);
}
nmi_exit();
}
Contributors
| Person | Tokens | Prop | Commits | CommitProp |
| Heiko Carstens | 314 | 69.62% | 13 | 59.09% |
| Martin Schwidefsky | 106 | 23.50% | 6 | 27.27% |
| Linus Torvalds | 27 | 5.99% | 1 | 4.55% |
| Andrew Morton | 2 | 0.44% | 1 | 4.55% |
| Christoph Lameter | 2 | 0.44% | 1 | 4.55% |
| Total | 451 | 100.00% | 22 | 100.00% |
static int __init machine_check_init(void)
{
ctl_set_bit(14, 25); /* enable external damage MCH */
ctl_set_bit(14, 27); /* enable system recovery MCH */
ctl_set_bit(14, 24); /* enable warning MCH */
return 0;
}
Contributors
| Person | Tokens | Prop | Commits | CommitProp |
| Martin Schwidefsky | 35 | 97.22% | 3 | 75.00% |
| Heiko Carstens | 1 | 2.78% | 1 | 25.00% |
| Total | 36 | 100.00% | 4 | 100.00% |
early_initcall(machine_check_init);
Overall Contributors
| Person | Tokens | Prop | Commits | CommitProp |
| Heiko Carstens | 817 | 71.54% | 24 | 52.17% |
| Martin Schwidefsky | 253 | 22.15% | 11 | 23.91% |
| Linus Torvalds | 34 | 2.98% | 1 | 2.17% |
| Hendrik Brueckner | 7 | 0.61% | 1 | 2.17% |
| Sebastian Ott | 7 | 0.61% | 1 | 2.17% |
| Ingo Molnar | 6 | 0.53% | 1 | 2.17% |
| Christian Bornträger | 5 | 0.44% | 1 | 2.17% |
| Andrew Morton | 5 | 0.44% | 2 | 4.35% |
| Christoph Lameter | 4 | 0.35% | 1 | 2.17% |
| Serge E. Hallyn | 2 | 0.18% | 1 | 2.17% |
| Cédric Le Goater | 1 | 0.09% | 1 | 2.17% |
| Paul Gortmaker | 1 | 0.09% | 1 | 2.17% |
| Total | 1142 | 100.00% | 46 | 100.00% |
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