[PATCH v4 14/15] drivers/firmware/sdei: Expose struct sdei_event

[Gavin Shan <gshan@redhat.com>]

This splits struct sdei_event into two structs: sdei_event and
sdei_internal_event. The former one can be dereferenced from external
module like arm64/kvm when SDEI virtualization is supported. The later
one is used by the client driver only.

This also renames local variables from @event to @event_el if their
type is "struct sdei_internal_event" to make the variable name a bit
meaningful. Note that it's not applied to sdei_do_{local,cross}_call()
because CROSSCALL_INIT stops us doing this unless much more changes
are needed. I'm avoiding to do that.

Besides, @event is added as "struct sdei_event" to cache @event_el->event
if it's accessed for multiple times in the particular function to reduce
the code change size.

This shouldn't cause functional changes.

Signed-off-by: Gavin Shan <gshan@redhat.com>
---
v4: Rename variable @event to @event_el if it's internal event
    Use @event to cache @event_el->event if it's used for multiple times
---
 drivers/firmware/arm_sdei.c | 160 ++++++++++++++++++++----------------
 include/linux/arm_sdei.h    |   6 ++
 2 files changed, 94 insertions(+), 72 deletions(-)

diff --git a/drivers/firmware/arm_sdei.c b/drivers/firmware/arm_sdei.c
index 2678475940e6..f9827c096275 100644
--- a/drivers/firmware/arm_sdei.c
+++ b/drivers/firmware/arm_sdei.c
@@ -44,16 +44,14 @@ static asmlinkage void (*sdei_firmware_call)(unsigned long function_id,
 /* entry point from firmware to arch asm code */
 static unsigned long sdei_entry_point;
 
-struct sdei_event {
+struct sdei_internal_event {
+	struct sdei_event	event;
+
 	/* These three are protected by the sdei_list_lock */
 	struct list_head	list;
 	bool			reregister;
 	bool			reenable;
 
-	u32			event_num;
-	u8			type;
-	u8			priority;
-
 	/* This pointer is handed to firmware as the event argument. */
 	union {
 		/* Shared events */
@@ -73,7 +71,7 @@ static LIST_HEAD(sdei_list);
 
 /* Private events are registered/enabled via IPI passing one of these */
 struct sdei_crosscall_args {
-	struct sdei_event *event;
+	struct sdei_internal_event *event;
 	atomic_t errors;
 	int first_error;
 };
@@ -86,7 +84,7 @@ struct sdei_crosscall_args {
 	} while (0)
 
 static inline int sdei_do_local_call(smp_call_func_t fn,
-				     struct sdei_event *event)
+				     struct sdei_internal_event *event)
 {
 	struct sdei_crosscall_args arg;
 
@@ -97,7 +95,7 @@ static inline int sdei_do_local_call(smp_call_func_t fn,
 }
 
 static inline int sdei_do_cross_call(smp_call_func_t fn,
-				     struct sdei_event *event)
+				     struct sdei_internal_event *event)
 {
 	struct sdei_crosscall_args arg;
 
@@ -162,16 +160,16 @@ static int invoke_sdei_fn(unsigned long function_id, unsigned long arg0,
 }
 NOKPROBE_SYMBOL(invoke_sdei_fn);
 
-static struct sdei_event *sdei_event_find(u32 event_num)
+static struct sdei_internal_event *sdei_event_find(u32 event_num)
 {
-	struct sdei_event *e, *found = NULL;
+	struct sdei_internal_event *event_el, *found = NULL;
 
 	lockdep_assert_held(&sdei_events_lock);
 
 	spin_lock(&sdei_list_lock);
-	list_for_each_entry(e, &sdei_list, list) {
-		if (e->event_num == event_num) {
-			found = e;
+	list_for_each_entry(event_el, &sdei_list, list) {
+		if (event_el->event.event_num == event_num) {
+			found = event_el;
 			break;
 		}
 	}
@@ -193,24 +191,26 @@ static int sdei_api_event_get_info(u32 event, u32 info, u64 *result)
 			      0, 0, result);
 }
 
-static struct sdei_event *sdei_event_create(u32 event_num,
-					    sdei_event_callback *cb,
-					    void *cb_arg)
+static struct sdei_internal_event *sdei_event_create(u32 event_num,
+						     sdei_event_callback *cb,
+						     void *cb_arg)
 {
 	int err;
 	u64 result;
+	struct sdei_internal_event *event_el;
 	struct sdei_event *event;
 	struct sdei_registered_event *reg;
 
 	lockdep_assert_held(&sdei_events_lock);
 
-	event = kzalloc(sizeof(*event), GFP_KERNEL);
-	if (!event) {
+	event_el = kzalloc(sizeof(*event_el), GFP_KERNEL);
+	if (!event_el) {
 		err = -ENOMEM;
 		goto fail;
 	}
 
-	INIT_LIST_HEAD(&event->list);
+	event = &event_el->event;
+	INIT_LIST_HEAD(&event_el->list);
 	event->event_num = event_num;
 
 	err = sdei_api_event_get_info(event_num, SDEI_EVENT_INFO_EV_PRIORITY,
@@ -237,7 +237,7 @@ static struct sdei_event *sdei_event_create(u32 event_num,
 
 		reg->callback = cb;
 		reg->callback_arg = cb_arg;
-		event->registered = reg;
+		event_el->registered = reg;
 	} else {
 		int cpu;
 		struct sdei_registered_event __percpu *regs;
@@ -257,39 +257,39 @@ static struct sdei_event *sdei_event_create(u32 event_num,
 			reg->callback_arg = cb_arg;
 		}
 
-		event->private_registered = regs;
+		event_el->private_registered = regs;
 	}
 
 	spin_lock(&sdei_list_lock);
-	list_add(&event->list, &sdei_list);
+	list_add(&event_el->list, &sdei_list);
 	spin_unlock(&sdei_list_lock);
 
-	return event;
+	return event_el;
 
 fail:
-	kfree(event);
+	kfree(event_el);
 	return ERR_PTR(err);
 }
 
-static void sdei_event_destroy_llocked(struct sdei_event *event)
+static void sdei_event_destroy_llocked(struct sdei_internal_event *event_el)
 {
 	lockdep_assert_held(&sdei_events_lock);
 	lockdep_assert_held(&sdei_list_lock);
 
-	list_del(&event->list);
+	list_del(&event_el->list);
 
-	if (event->type == SDEI_EVENT_TYPE_SHARED)
-		kfree(event->registered);
+	if (event_el->event.type == SDEI_EVENT_TYPE_SHARED)
+		kfree(event_el->registered);
 	else
-		free_percpu(event->private_registered);
+		free_percpu(event_el->private_registered);
 
-	kfree(event);
+	kfree(event_el);
 }
 
-static void sdei_event_destroy(struct sdei_event *event)
+static void sdei_event_destroy(struct sdei_internal_event *event_el)
 {
 	spin_lock(&sdei_list_lock);
-	sdei_event_destroy_llocked(event);
+	sdei_event_destroy_llocked(event_el);
 	spin_unlock(&sdei_list_lock);
 }
 
@@ -392,7 +392,7 @@ static void _local_event_enable(void *data)
 
 	WARN_ON_ONCE(preemptible());
 
-	err = sdei_api_event_enable(arg->event->event_num);
+	err = sdei_api_event_enable(arg->event->event.event_num);
 
 	sdei_cross_call_return(arg, err);
 }
@@ -400,25 +400,27 @@ static void _local_event_enable(void *data)
 int sdei_event_enable(u32 event_num)
 {
 	int err = -EINVAL;
+	struct sdei_internal_event *event_el;
 	struct sdei_event *event;
 
 	mutex_lock(&sdei_events_lock);
-	event = sdei_event_find(event_num);
-	if (!event) {
+	event_el = sdei_event_find(event_num);
+	if (!event_el) {
 		mutex_unlock(&sdei_events_lock);
 		return -ENOENT;
 	}
 
 
 	cpus_read_lock();
+	event = &event_el->event;
 	if (event->type == SDEI_EVENT_TYPE_SHARED)
 		err = sdei_api_event_enable(event->event_num);
 	else
-		err = sdei_do_cross_call(_local_event_enable, event);
+		err = sdei_do_cross_call(_local_event_enable, event_el);
 
 	if (!err) {
 		spin_lock(&sdei_list_lock);
-		event->reenable = true;
+		event_el->reenable = true;
 		spin_unlock(&sdei_list_lock);
 	}
 	cpus_read_unlock();
@@ -438,7 +440,7 @@ static void _ipi_event_disable(void *data)
 	int err;
 	struct sdei_crosscall_args *arg = data;
 
-	err = sdei_api_event_disable(arg->event->event_num);
+	err = sdei_api_event_disable(arg->event->event.event_num);
 
 	sdei_cross_call_return(arg, err);
 }
@@ -446,23 +448,25 @@ static void _ipi_event_disable(void *data)
 int sdei_event_disable(u32 event_num)
 {
 	int err = -EINVAL;
+	struct sdei_internal_event *event_el;
 	struct sdei_event *event;
 
 	mutex_lock(&sdei_events_lock);
-	event = sdei_event_find(event_num);
-	if (!event) {
+	event_el = sdei_event_find(event_num);
+	if (!event_el) {
 		mutex_unlock(&sdei_events_lock);
 		return -ENOENT;
 	}
 
 	spin_lock(&sdei_list_lock);
-	event->reenable = false;
+	event_el->reenable = false;
 	spin_unlock(&sdei_list_lock);
 
+	event = &event_el->event;
 	if (event->type == SDEI_EVENT_TYPE_SHARED)
 		err = sdei_api_event_disable(event->event_num);
 	else
-		err = sdei_do_cross_call(_ipi_event_disable, event);
+		err = sdei_do_cross_call(_ipi_event_disable, event_el);
 	mutex_unlock(&sdei_events_lock);
 
 	return err;
@@ -482,7 +486,7 @@ static void _local_event_unregister(void *data)
 
 	WARN_ON_ONCE(preemptible());
 
-	err = sdei_api_event_unregister(arg->event->event_num);
+	err = sdei_api_event_unregister(arg->event->event.event_num);
 
 	sdei_cross_call_return(arg, err);
 }
@@ -490,32 +494,34 @@ static void _local_event_unregister(void *data)
 int sdei_event_unregister(u32 event_num)
 {
 	int err;
+	struct sdei_internal_event *event_el;
 	struct sdei_event *event;
 
 	WARN_ON(in_nmi());
 
 	mutex_lock(&sdei_events_lock);
-	event = sdei_event_find(event_num);
-	if (!event) {
+	event_el = sdei_event_find(event_num);
+	if (!event_el) {
 		pr_warn("Event %u not registered\n", event_num);
 		err = -ENOENT;
 		goto unlock;
 	}
 
 	spin_lock(&sdei_list_lock);
-	event->reregister = false;
-	event->reenable = false;
+	event_el->reregister = false;
+	event_el->reenable = false;
 	spin_unlock(&sdei_list_lock);
 
+	event = &event_el->event;
 	if (event->type == SDEI_EVENT_TYPE_SHARED)
 		err = sdei_api_event_unregister(event->event_num);
 	else
-		err = sdei_do_cross_call(_local_event_unregister, event);
+		err = sdei_do_cross_call(_local_event_unregister, event_el);
 
 	if (err)
 		goto unlock;
 
-	sdei_event_destroy(event);
+	sdei_event_destroy(event_el);
 unlock:
 	mutex_unlock(&sdei_events_lock);
 
@@ -529,11 +535,13 @@ int sdei_event_unregister(u32 event_num)
 static int sdei_unregister_shared(void)
 {
 	int err = 0;
+	struct sdei_internal_event *event_el;
 	struct sdei_event *event;
 
 	mutex_lock(&sdei_events_lock);
 	spin_lock(&sdei_list_lock);
-	list_for_each_entry(event, &sdei_list, list) {
+	list_for_each_entry(event_el, &sdei_list, list) {
+		event = &event_el->event;
 		if (event->type != SDEI_EVENT_TYPE_SHARED)
 			continue;
 
@@ -565,8 +573,8 @@ static void _local_event_register(void *data)
 	WARN_ON(preemptible());
 
 	reg = per_cpu_ptr(arg->event->private_registered, smp_processor_id());
-	err = sdei_api_event_register(arg->event->event_num, sdei_entry_point,
-				      reg, 0, 0);
+	err = sdei_api_event_register(arg->event->event.event_num,
+				      sdei_entry_point, reg, 0, 0);
 
 	sdei_cross_call_return(arg, err);
 }
@@ -574,6 +582,7 @@ static void _local_event_register(void *data)
 int sdei_event_register(u32 event_num, sdei_event_callback *cb, void *arg)
 {
 	int err;
+	struct sdei_internal_event *event_el;
 	struct sdei_event *event;
 
 	WARN_ON(in_nmi());
@@ -585,33 +594,34 @@ int sdei_event_register(u32 event_num, sdei_event_callback *cb, void *arg)
 		goto unlock;
 	}
 
-	event = sdei_event_create(event_num, cb, arg);
-	if (IS_ERR(event)) {
-		err = PTR_ERR(event);
+	event_el = sdei_event_create(event_num, cb, arg);
+	if (IS_ERR(event_el)) {
+		err = PTR_ERR(event_el);
 		pr_warn("Failed to create event %u: %d\n", event_num, err);
 		goto unlock;
 	}
 
 	cpus_read_lock();
+	event = &event_el->event;
 	if (event->type == SDEI_EVENT_TYPE_SHARED) {
 		err = sdei_api_event_register(event->event_num,
 					      sdei_entry_point,
-					      event->registered,
+					      event_el->registered,
 					      SDEI_EVENT_REGISTER_RM_ANY, 0);
 	} else {
-		err = sdei_do_cross_call(_local_event_register, event);
+		err = sdei_do_cross_call(_local_event_register, event_el);
 		if (err)
-			sdei_do_cross_call(_local_event_unregister, event);
+			sdei_do_cross_call(_local_event_unregister, event_el);
 	}
 
 	if (err) {
-		sdei_event_destroy(event);
+		sdei_event_destroy(event_el);
 		pr_warn("Failed to register event %u: %d\n", event_num, err);
 		goto cpu_unlock;
 	}
 
 	spin_lock(&sdei_list_lock);
-	event->reregister = true;
+	event_el->reregister = true;
 	spin_unlock(&sdei_list_lock);
 cpu_unlock:
 	cpus_read_unlock();
@@ -623,27 +633,29 @@ int sdei_event_register(u32 event_num, sdei_event_callback *cb, void *arg)
 static int sdei_reregister_shared(void)
 {
 	int err = 0;
+	struct sdei_internal_event *event_el;
 	struct sdei_event *event;
 
 	mutex_lock(&sdei_events_lock);
 	spin_lock(&sdei_list_lock);
-	list_for_each_entry(event, &sdei_list, list) {
+	list_for_each_entry(event_el, &sdei_list, list) {
+		event = &event_el->event;
 		if (event->type != SDEI_EVENT_TYPE_SHARED)
 			continue;
 
-		if (event->reregister) {
+		if (event_el->reregister) {
 			err = sdei_api_event_register(event->event_num,
-					sdei_entry_point, event->registered,
+					sdei_entry_point, event_el->registered,
 					SDEI_EVENT_REGISTER_RM_ANY, 0);
 			if (err) {
-				sdei_event_destroy_llocked(event);
+				sdei_event_destroy_llocked(event_el);
 				pr_err("Failed to re-register event %u\n",
 				       event->event_num);
 				break;
 			}
 		}
 
-		if (event->reenable) {
+		if (event_el->reenable) {
 			err = sdei_api_event_enable(event->event_num);
 			if (err) {
 				pr_err("Failed to re-enable event %u\n",
@@ -660,16 +672,18 @@ static int sdei_reregister_shared(void)
 
 static int sdei_cpuhp_down(unsigned int cpu)
 {
+	struct sdei_internal_event *event_el;
 	struct sdei_event *event;
 	int err;
 
 	/* un-register private events */
 	spin_lock(&sdei_list_lock);
-	list_for_each_entry(event, &sdei_list, list) {
+	list_for_each_entry(event_el, &sdei_list, list) {
+		event = &event_el->event;
 		if (event->type == SDEI_EVENT_TYPE_SHARED)
 			continue;
 
-		err = sdei_do_local_call(_local_event_unregister, event);
+		err = sdei_do_local_call(_local_event_unregister, event_el);
 		if (err) {
 			pr_err("Failed to unregister event %u: %d\n",
 			       event->event_num, err);
@@ -682,25 +696,27 @@ static int sdei_cpuhp_down(unsigned int cpu)
 
 static int sdei_cpuhp_up(unsigned int cpu)
 {
+	struct sdei_internal_event *event_el;
 	struct sdei_event *event;
 	int err;
 
 	/* re-register/enable private events */
 	spin_lock(&sdei_list_lock);
-	list_for_each_entry(event, &sdei_list, list) {
+	list_for_each_entry(event_el, &sdei_list, list) {
+		event = &event_el->event;
 		if (event->type == SDEI_EVENT_TYPE_SHARED)
 			continue;
 
-		if (event->reregister) {
-			err = sdei_do_local_call(_local_event_register, event);
+		if (event_el->reregister) {
+			err = sdei_do_local_call(_local_event_register, event_el);
 			if (err) {
 				pr_err("Failed to re-register event %u: %d\n",
 				       event->event_num, err);
 			}
 		}
 
-		if (event->reenable) {
-			err = sdei_do_local_call(_local_event_enable, event);
+		if (event_el->reenable) {
+			err = sdei_do_local_call(_local_event_enable, event_el);
 			if (err) {
 				pr_err("Failed to re-enable event %u: %d\n",
 				       event->event_num, err);
diff --git a/include/linux/arm_sdei.h b/include/linux/arm_sdei.h
index 0a241c5c911d..d2464a18b6ff 100644
--- a/include/linux/arm_sdei.h
+++ b/include/linux/arm_sdei.h
@@ -22,6 +22,12 @@
  */
 typedef int (sdei_event_callback)(u32 event, struct pt_regs *regs, void *arg);
 
+struct sdei_event {
+	u32			event_num;
+	u8			type;
+	u8			priority;
+};
+
 /*
  * Register your callback to claim an event. The event must be described
  * by firmware.
-- 
2.23.0


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