summaryrefslogtreecommitdiff
diff options
context:
space:
mode:
authorGanesh Goudar <ganeshgr@linux.ibm.com>2022-01-20 15:19:31 +0300
committerMichael Ellerman <mpe@ellerman.id.au>2022-03-07 16:05:00 +0300
commitcc15ff3275694fedc33cd3d53212a43eec7aa0bc (patch)
treedc15adec5a7491d5c1d6405e63169188942d45a8
parent0a182611d149b5b747014fbb230ec35b20a45c86 (diff)
downloadlinux-cc15ff3275694fedc33cd3d53212a43eec7aa0bc.tar.xz
powerpc/mce: Avoid using irq_work_queue() in realmode
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 <ganeshgr@linux.ibm.com> Signed-off-by: Michael Ellerman <mpe@ellerman.id.au> Link: https://lore.kernel.org/r/20220120121931.517974-1-ganeshgr@linux.ibm.com
-rw-r--r--arch/powerpc/include/asm/machdep.h2
-rw-r--r--arch/powerpc/include/asm/mce.h13
-rw-r--r--arch/powerpc/include/asm/paca.h1
-rw-r--r--arch/powerpc/kernel/mce.c60
-rw-r--r--arch/powerpc/kernel/time.c2
-rw-r--r--arch/powerpc/platforms/pseries/pseries.h1
-rw-r--r--arch/powerpc/platforms/pseries/ras.c32
-rw-r--r--arch/powerpc/platforms/pseries/setup.c1
8 files changed, 53 insertions, 59 deletions
diff --git a/arch/powerpc/include/asm/machdep.h b/arch/powerpc/include/asm/machdep.h
index 06ac7ef07c85..358d171ae8e0 100644
--- a/arch/powerpc/include/asm/machdep.h
+++ b/arch/powerpc/include/asm/machdep.h
@@ -94,6 +94,8 @@ 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..c9f0936bd3c9 100644
--- a/arch/powerpc/include/asm/mce.h
+++ b/arch/powerpc/include/asm/mce.h
@@ -235,8 +235,21 @@ 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 mce_irq_work_queue(void);
int mce_register_notifier(struct notifier_block *nb);
int mce_unregister_notifier(struct notifier_block *nb);
+
+#ifdef CONFIG_PPC_BOOK3S_64
+void mce_run_irq_context_handlers(void);
+#else
+static inline void mce_run_irq_context_handlers(void) { };
+#endif /* CONFIG_PPC_BOOK3S_64 */
+
+#ifdef CONFIG_PPC_BOOK3S_64
+void set_mce_pending_irq_work(void);
+void clear_mce_pending_irq_work(void);
+#endif /* CONFIG_PPC_BOOK3S_64 */
+
#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 295573a82c66..8330968ca346 100644
--- a/arch/powerpc/include/asm/paca.h
+++ b/arch/powerpc/include/asm/paca.h
@@ -288,6 +288,7 @@ struct paca_struct {
#endif
#ifdef CONFIG_PPC_BOOK3S_64
struct mce_info *mce_info;
+ u8 mce_pending_irq_work;
#endif /* CONFIG_PPC_BOOK3S_64 */
} ____cacheline_aligned;
diff --git a/arch/powerpc/kernel/mce.c b/arch/powerpc/kernel/mce.c
index 811c867ad6c6..671d727d06f7 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 +79,13 @@ static void mce_set_error_info(struct machine_check_event *mce,
}
}
+void mce_irq_work_queue(void)
+{
+ /* Raise decrementer interrupt */
+ arch_irq_work_raise();
+ set_mce_pending_irq_work();
+}
+
/*
* Decode and save high level MCE information into per cpu buffer which
* is an array of machine_check_event structure.
@@ -217,7 +214,7 @@ 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 +236,7 @@ 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);
+ mce_irq_work_queue();
}
/*
@@ -249,7 +246,6 @@ 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 +259,7 @@ 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);
- }
+ mce_irq_work_queue();
}
void mce_common_process_ue(struct pt_regs *regs,
@@ -338,7 +321,7 @@ 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 +346,27 @@ static void machine_check_process_queued_event(struct irq_work *work)
}
}
+void set_mce_pending_irq_work(void)
+{
+ local_paca->mce_pending_irq_work = 1;
+}
+
+void clear_mce_pending_irq_work(void)
+{
+ local_paca->mce_pending_irq_work = 0;
+}
+
+void mce_run_irq_context_handlers(void)
+{
+ if (unlikely(local_paca->mce_pending_irq_work)) {
+ if (ppc_md.machine_check_log_err)
+ ppc_md.machine_check_log_err();
+ machine_check_process_queued_event();
+ machine_check_ue_work();
+ clear_mce_pending_irq_work();
+ }
+}
+
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 cd0b8b71ecdd..17598bba54eb 100644
--- a/arch/powerpc/kernel/time.c
+++ b/arch/powerpc/kernel/time.c
@@ -70,6 +70,7 @@
#include <asm/vdso_datapage.h>
#include <asm/firmware.h>
#include <asm/asm-prototypes.h>
+#include <asm/mce.h>
/* powerpc clocksource/clockevent code */
@@ -638,6 +639,7 @@ DEFINE_INTERRUPT_HANDLER_ASYNC(timer_interrupt)
if (test_irq_work_pending()) {
clear_irq_work_pending();
+ mce_run_irq_context_handlers();
irq_work_run();
}
diff --git a/arch/powerpc/platforms/pseries/pseries.h b/arch/powerpc/platforms/pseries/pseries.h
index 56c9ef9052e9..af162aeeae86 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 2a158e828c99..f12516c3998c 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
@@ -745,7 +740,6 @@ static int mce_handle_error(struct pt_regs *regs, struct rtas_error_log *errp)
struct pseries_errorlog *pseries_log;
struct pseries_mc_errorlog *mce_log = NULL;
int disposition = rtas_error_disposition(errp);
- unsigned long msr;
u8 error_type;
if (!rtas_error_extended(errp))
@@ -759,40 +753,16 @@ 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 83a04d967a59..069d7b3bb142 100644
--- a/arch/powerpc/platforms/pseries/setup.c
+++ b/arch/powerpc/platforms/pseries/setup.c
@@ -1086,6 +1086,7 @@ 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,