In realmode mce handler we use irq_work_queue() to defer
the processing of mce events, irq_work_queue() can only
be called when translation is enabled because it touches
memory outside RMA, hence we enable translation before
calling irq_work_queue and disable on return, though it
is not safe to do in realmode.
To avoid this, program the decrementer and call the event
processing functions from timer handler.
Signed-off-by: Ganesh Goudar <ganes...@linux.ibm.com>
---
V2:
* Use arch_irq_work_raise to raise decrementer interrupt.
* Avoid having atomic variable.
---
arch/powerpc/include/asm/machdep.h | 2 +
arch/powerpc/include/asm/mce.h | 2 +
arch/powerpc/include/asm/paca.h | 1 +
arch/powerpc/kernel/mce.c | 51 +++++++++++-------------
arch/powerpc/kernel/time.c | 2 +
arch/powerpc/platforms/pseries/pseries.h | 1 +
arch/powerpc/platforms/pseries/ras.c | 31 +-------------
arch/powerpc/platforms/pseries/setup.c | 1 +
8 files changed, 33 insertions(+), 58 deletions(-)
diff --git a/arch/powerpc/include/asm/machdep.h
b/arch/powerpc/include/asm/machdep.h
index 9c3c9f04129f..d22b222ba471 100644
--- a/arch/powerpc/include/asm/machdep.h
+++ b/arch/powerpc/include/asm/machdep.h
@@ -99,6 +99,8 @@ struct machdep_calls {
/* Called during machine check exception to retrive fixup address. */
bool (*mce_check_early_recovery)(struct pt_regs *regs);
+ void (*machine_check_log_err)(void);
+
/* Motherboard/chipset features. This is a kind of general purpose
* hook used to control some machine specific features (like reset
* lines, chip power control, etc...).
diff --git a/arch/powerpc/include/asm/mce.h b/arch/powerpc/include/asm/mce.h
index 331d944280b8..6e306aaf58aa 100644
--- a/arch/powerpc/include/asm/mce.h
+++ b/arch/powerpc/include/asm/mce.h
@@ -235,8 +235,10 @@ extern void machine_check_print_event_info(struct
machine_check_event *evt,
unsigned long addr_to_pfn(struct pt_regs *regs, unsigned long addr);
extern void mce_common_process_ue(struct pt_regs *regs,
struct mce_error_info *mce_err);
+void machine_check_raise_dec_intr(void);
int mce_register_notifier(struct notifier_block *nb);
int mce_unregister_notifier(struct notifier_block *nb);
+void mce_run_late_handlers(void);
#ifdef CONFIG_PPC_BOOK3S_64
void flush_and_reload_slb(void);
void flush_erat(void);
diff --git a/arch/powerpc/include/asm/paca.h b/arch/powerpc/include/asm/paca.h
index dc05a862e72a..d463c796f7fa 100644
--- a/arch/powerpc/include/asm/paca.h
+++ b/arch/powerpc/include/asm/paca.h
@@ -280,6 +280,7 @@ struct paca_struct {
#endif
#ifdef CONFIG_PPC_BOOK3S_64
struct mce_info *mce_info;
+ u32 mces_to_process;
#endif /* CONFIG_PPC_BOOK3S_64 */
} ____cacheline_aligned;
diff --git a/arch/powerpc/kernel/mce.c b/arch/powerpc/kernel/mce.c
index fd829f7f25a4..8e17f29472a0 100644
--- a/arch/powerpc/kernel/mce.c
+++ b/arch/powerpc/kernel/mce.c
@@ -28,19 +28,9 @@
#include "setup.h"
-static void machine_check_process_queued_event(struct irq_work *work);
-static void machine_check_ue_irq_work(struct irq_work *work);
static void machine_check_ue_event(struct machine_check_event *evt);
static void machine_process_ue_event(struct work_struct *work);
-static struct irq_work mce_event_process_work = {
- .func = machine_check_process_queued_event,
-};
-
-static struct irq_work mce_ue_event_irq_work = {
- .func = machine_check_ue_irq_work,
-};
-
static DECLARE_WORK(mce_ue_event_work, machine_process_ue_event);
static BLOCKING_NOTIFIER_HEAD(mce_notifier_list);
@@ -89,6 +79,12 @@ static void mce_set_error_info(struct machine_check_event
*mce,
}
}
+/* Raise decrementer interrupt */
+void machine_check_raise_dec_intr(void)
+{
+ arch_irq_work_raise();
+}
+
/*
* Decode and save high level MCE information into per cpu buffer which
* is an array of machine_check_event structure.
@@ -135,6 +131,8 @@ void save_mce_event(struct pt_regs *regs, long handled,
if (mce->error_type == MCE_ERROR_TYPE_UE)
mce->u.ue_error.ignore_event = mce_err->ignore_event;
+ local_paca->mces_to_process++;
+
if (!addr)
return;
@@ -217,7 +215,7 @@ void release_mce_event(void)
get_mce_event(NULL, true);
}
-static void machine_check_ue_irq_work(struct irq_work *work)
+static void machine_check_ue_work(void)
{
schedule_work(&mce_ue_event_work);
}
@@ -239,7 +237,7 @@ static void machine_check_ue_event(struct
machine_check_event *evt)
evt, sizeof(*evt));
/* Queue work to process this event later. */
- irq_work_queue(&mce_ue_event_irq_work);
+ machine_check_raise_dec_intr();
}
/*
@@ -249,7 +247,6 @@ void machine_check_queue_event(void)
{
int index;
struct machine_check_event evt;
- unsigned long msr;
if (!get_mce_event(&evt, MCE_EVENT_RELEASE))
return;
@@ -263,20 +260,7 @@ void machine_check_queue_event(void)
memcpy(&local_paca->mce_info->mce_event_queue[index],
&evt, sizeof(evt));
- /*
- * Queue irq work to process this event later. Before
- * queuing the work enable translation for non radix LPAR,
- * as irq_work_queue may try to access memory outside RMO
- * region.
- */
- if (!radix_enabled() && firmware_has_feature(FW_FEATURE_LPAR)) {
- msr = mfmsr();
- mtmsr(msr | MSR_IR | MSR_DR);
- irq_work_queue(&mce_event_process_work);
- mtmsr(msr);
- } else {
- irq_work_queue(&mce_event_process_work);
- }
+ machine_check_raise_dec_intr();
}
void mce_common_process_ue(struct pt_regs *regs,
@@ -338,7 +322,7 @@ static void machine_process_ue_event(struct work_struct
*work)
* process pending MCE event from the mce event queue. This function will be
* called during syscall exit.
*/
-static void machine_check_process_queued_event(struct irq_work *work)
+static void machine_check_process_queued_event(void)
{
int index;
struct machine_check_event *evt;
@@ -363,6 +347,17 @@ static void machine_check_process_queued_event(struct
irq_work *work)
}
}
+void mce_run_late_handlers(void)
+{
+ if (unlikely(local_paca->mces_to_process)) {
+ if (ppc_md.machine_check_log_err)
+ ppc_md.machine_check_log_err();
+ machine_check_process_queued_event();
+ machine_check_ue_work();
+ local_paca->mces_to_process--;
+ }
+}
+
void machine_check_print_event_info(struct machine_check_event *evt,
bool user_mode, bool in_guest)
{
diff --git a/arch/powerpc/kernel/time.c b/arch/powerpc/kernel/time.c
index cae8f03a44fe..eaf63c648554 100644
--- a/arch/powerpc/kernel/time.c
+++ b/arch/powerpc/kernel/time.c
@@ -594,6 +594,8 @@ DEFINE_INTERRUPT_HANDLER_ASYNC(timer_interrupt)
if (test_irq_work_pending()) {
clear_irq_work_pending();
+ if (IS_ENABLED(CONFIG_PPC_BOOK3S_64))
+ mce_run_late_handlers();
irq_work_run();
}
diff --git a/arch/powerpc/platforms/pseries/pseries.h
b/arch/powerpc/platforms/pseries/pseries.h
index 3544778e06d0..9cf0d33dfbf5 100644
--- a/arch/powerpc/platforms/pseries/pseries.h
+++ b/arch/powerpc/platforms/pseries/pseries.h
@@ -21,6 +21,7 @@ struct pt_regs;
extern int pSeries_system_reset_exception(struct pt_regs *regs);
extern int pSeries_machine_check_exception(struct pt_regs *regs);
extern long pseries_machine_check_realmode(struct pt_regs *regs);
+void pSeries_machine_check_log_err(void);
#ifdef CONFIG_SMP
extern void smp_init_pseries(void);
diff --git a/arch/powerpc/platforms/pseries/ras.c
b/arch/powerpc/platforms/pseries/ras.c
index 56092dccfdb8..8613f9cc5798 100644
--- a/arch/powerpc/platforms/pseries/ras.c
+++ b/arch/powerpc/platforms/pseries/ras.c
@@ -23,11 +23,6 @@ static DEFINE_SPINLOCK(ras_log_buf_lock);
static int ras_check_exception_token;
-static void mce_process_errlog_event(struct irq_work *work);
-static struct irq_work mce_errlog_process_work = {
- .func = mce_process_errlog_event,
-};
-
#define EPOW_SENSOR_TOKEN 9
#define EPOW_SENSOR_INDEX 0
@@ -729,40 +724,16 @@ static int mce_handle_error(struct pt_regs *regs, struct
rtas_error_log *errp)
error_type = mce_log->error_type;
disposition = mce_handle_err_realmode(disposition, error_type);
-
- /*
- * Enable translation as we will be accessing per-cpu variables
- * in save_mce_event() which may fall outside RMO region, also
- * leave it enabled because subsequently we will be queuing work
- * to workqueues where again per-cpu variables accessed, besides
- * fwnmi_release_errinfo() crashes when called in realmode on
- * pseries.
- * Note: All the realmode handling like flushing SLB entries for
- * SLB multihit is done by now.
- */
out:
- msr = mfmsr();
- mtmsr(msr | MSR_IR | MSR_DR);
-
disposition = mce_handle_err_virtmode(regs, errp, mce_log,
disposition);
-
- /*
- * Queue irq work to log this rtas event later.
- * irq_work_queue uses per-cpu variables, so do this in virt
- * mode as well.
- */
- irq_work_queue(&mce_errlog_process_work);
-
- mtmsr(msr);
-
return disposition;
}
/*
* Process MCE rtas errlog event.
*/
-static void mce_process_errlog_event(struct irq_work *work)
+void pSeries_machine_check_log_err(void)
{
struct rtas_error_log *err;
diff --git a/arch/powerpc/platforms/pseries/setup.c
b/arch/powerpc/platforms/pseries/setup.c
index 8a62af5b9c24..9bdc487b8e35 100644
--- a/arch/powerpc/platforms/pseries/setup.c
+++ b/arch/powerpc/platforms/pseries/setup.c
@@ -1084,6 +1084,7 @@ define_machine(pseries) {
.system_reset_exception = pSeries_system_reset_exception,
.machine_check_early = pseries_machine_check_realmode,
.machine_check_exception = pSeries_machine_check_exception,
+ .machine_check_log_err = pSeries_machine_check_log_err,
#ifdef CONFIG_KEXEC_CORE
.machine_kexec = pSeries_machine_kexec,
.kexec_cpu_down = pseries_kexec_cpu_down,
--
2.31.1
