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ACPI / APEI: Move NOTIFY_SEA between the estatus-queue and NOTIFY_NMI

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The estatus-queue code is currently hidden by the NOTIFY_NMI #ifdefs.
Once NOTIFY_SEA starts using the estatus-queue we can stop hiding
it as each architecture has a user that can't be turned off.

Split the existing CONFIG_HAVE_ACPI_APEI_NMI block in two, and move
the SEA code into the gap.

Move the code around ... and changes the stale comment describing
why the status queue is necessary: printk() is no longer the issue,
its the helpers like memory_failure_queue() that aren't nmi safe.

Signed-off-by: James Morse <james.morse@arm.com>
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
This commit is contained in:
James Morse
2019-01-29 18:48:47 +00:00
committed by Rafael J. Wysocki
parent 06ddeadc8d
commit 9c9d080513
1 changed files with 59 additions and 54 deletions
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113
drivers/acpi/apei/ghes.c
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@ -767,66 +767,21 @@ static struct notifier_block ghes_notifier_hed = {
.notifier_call = ghes_notify_hed,
};
#ifdef CONFIG_ACPI_APEI_SEA
static LIST_HEAD(ghes_sea);
/*
* Return 0 only if one of the SEA error sources successfully reported an error
* record sent from the firmware.
*/
int ghes_notify_sea(void)
{
struct ghes *ghes;
int ret = -ENOENT;
rcu_read_lock();
list_for_each_entry_rcu(ghes, &ghes_sea, list) {
if (!ghes_proc(ghes))
ret = 0;
}
rcu_read_unlock();
return ret;
}
static void ghes_sea_add(struct ghes *ghes)
{
mutex_lock(&ghes_list_mutex);
list_add_rcu(&ghes->list, &ghes_sea);
mutex_unlock(&ghes_list_mutex);
}
static void ghes_sea_remove(struct ghes *ghes)
{
mutex_lock(&ghes_list_mutex);
list_del_rcu(&ghes->list);
mutex_unlock(&ghes_list_mutex);
synchronize_rcu();
}
#else /* CONFIG_ACPI_APEI_SEA */
static inline void ghes_sea_add(struct ghes *ghes) { }
static inline void ghes_sea_remove(struct ghes *ghes) { }
#endif /* CONFIG_ACPI_APEI_SEA */
#ifdef CONFIG_HAVE_ACPI_APEI_NMI
/*
* printk is not safe in NMI context. So in NMI handler, we allocate
* required memory from lock-less memory allocator
* (ghes_estatus_pool), save estatus into it, put them into lock-less
* list (ghes_estatus_llist), then delay printk into IRQ context via
* irq_work (ghes_proc_irq_work). ghes_estatus_size_request record
* required pool size by all NMI error source.
* Handlers for CPER records may not be NMI safe. For example,
* memory_failure_queue() takes spinlocks and calls schedule_work_on().
* In any NMI-like handler, memory from ghes_estatus_pool is used to save
* estatus, and added to the ghes_estatus_llist. irq_work_queue() causes
* ghes_proc_in_irq() to run in IRQ context where each estatus in
* ghes_estatus_llist is processed.
*
* Memory from the ghes_estatus_pool is also used with the ghes_estatus_cache
* to suppress frequent messages.
*/
static struct llist_head ghes_estatus_llist;
static struct irq_work ghes_proc_irq_work;
/*
* NMI may be triggered on any CPU, so ghes_in_nmi is used for
* having only one concurrent reader.
*/
static atomic_t ghes_in_nmi = ATOMIC_INIT(0);
static LIST_HEAD(ghes_nmi);
static void ghes_proc_in_irq(struct irq_work *irq_work)
{
struct llist_node *llnode, *next;
@ -948,6 +903,56 @@ static int ghes_in_nmi_spool_from_list(struct list_head *rcu_list)
return ret;
}
#endif /* CONFIG_HAVE_ACPI_APEI_NMI */
#ifdef CONFIG_ACPI_APEI_SEA
static LIST_HEAD(ghes_sea);
/*
* Return 0 only if one of the SEA error sources successfully reported an error
* record sent from the firmware.
*/
int ghes_notify_sea(void)
{
struct ghes *ghes;
int ret = -ENOENT;
rcu_read_lock();
list_for_each_entry_rcu(ghes, &ghes_sea, list) {
if (!ghes_proc(ghes))
ret = 0;
}
rcu_read_unlock();
return ret;
}
static void ghes_sea_add(struct ghes *ghes)
{
mutex_lock(&ghes_list_mutex);
list_add_rcu(&ghes->list, &ghes_sea);
mutex_unlock(&ghes_list_mutex);
}
static void ghes_sea_remove(struct ghes *ghes)
{
mutex_lock(&ghes_list_mutex);
list_del_rcu(&ghes->list);
mutex_unlock(&ghes_list_mutex);
synchronize_rcu();
}
#else /* CONFIG_ACPI_APEI_SEA */
static inline void ghes_sea_add(struct ghes *ghes) { }
static inline void ghes_sea_remove(struct ghes *ghes) { }
#endif /* CONFIG_ACPI_APEI_SEA */
#ifdef CONFIG_HAVE_ACPI_APEI_NMI
/*
* NMI may be triggered on any CPU, so ghes_in_nmi is used for
* having only one concurrent reader.
*/
static atomic_t ghes_in_nmi = ATOMIC_INIT(0);
static LIST_HEAD(ghes_nmi);
static int ghes_notify_nmi(unsigned int cmd, struct pt_regs *regs)
{