From: Cristian Marussi <cristian.marussi@arm.com>
To: linux-kernel@vger.kernel.org, linux-arm-kernel@lists.infradead.org
Cc: sudeep.holla@arm.com, lukasz.luba@arm.com,
james.quinlan@broadcom.com, Jonathan.Cameron@Huawei.com,
f.fainelli@gmail.com, etienne.carriere@linaro.org,
thara.gopinath@linaro.org, vincent.guittot@linaro.org,
souvik.chakravarty@arm.com, cristian.marussi@arm.com
Subject: [PATCH v4 05/37] firmware: arm_scmi: make notifications aware of protocols users
Date: Wed, 6 Jan 2021 20:15:38 +0000 [thread overview]
Message-ID: <20210106201610.26538-6-cristian.marussi@arm.com> (raw)
In-Reply-To: <20210106201610.26538-1-cristian.marussi@arm.com>
Account for any active registered notifier against the proper related
protocol; do not consider pending event handlers, only active handlers
will concur to protocol usage accounting.
Signed-off-by: Cristian Marussi <cristian.marussi@arm.com>
---
drivers/firmware/arm_scmi/notify.c | 51 ++++++++++++++++++++++++++----
1 file changed, 44 insertions(+), 7 deletions(-)
diff --git a/drivers/firmware/arm_scmi/notify.c b/drivers/firmware/arm_scmi/notify.c
index 66196b293b6c..cdaf0f962d84 100644
--- a/drivers/firmware/arm_scmi/notify.c
+++ b/drivers/firmware/arm_scmi/notify.c
@@ -91,6 +91,7 @@
#include <linux/types.h>
#include <linux/workqueue.h>
+#include "common.h"
#include "notify.h"
#define SCMI_MAX_PROTO 256
@@ -368,7 +369,7 @@ static struct scmi_event_handler *
scmi_get_active_handler(struct scmi_notify_instance *ni, u32 evt_key);
static void scmi_put_active_handler(struct scmi_notify_instance *ni,
struct scmi_event_handler *hndl);
-static void scmi_put_handler_unlocked(struct scmi_notify_instance *ni,
+static bool scmi_put_handler_unlocked(struct scmi_notify_instance *ni,
struct scmi_event_handler *hndl);
/**
@@ -900,9 +901,21 @@ static inline int scmi_bind_event_handler(struct scmi_notify_instance *ni,
if (!r_evt)
return -EINVAL;
- /* Remove from pending and insert into registered */
+ /*
+ * Remove from pending and insert into registered while getting hold
+ * of protocol instance.
+ */
hash_del(&hndl->hash);
+ /*
+ * Acquire protocols only for NON pending handlers, so as NOT to trigger
+ * protocol initialization when a notifier is registered against a still
+ * not registered protocol, since it would make little sense to force init
+ * protocols for which still no SCMI driver user exists: they wouldn't
+ * emit any event anyway till some SCMI driver starts using it.
+ */
+ scmi_acquire_protocol(ni->handle, KEY_XTRACT_PROTO_ID(hndl->key));
hndl->r_evt = r_evt;
+
mutex_lock(&r_evt->proto->registered_mtx);
hash_add(r_evt->proto->registered_events_handlers,
&hndl->hash, hndl->key);
@@ -1193,41 +1206,65 @@ static int scmi_disable_events(struct scmi_event_handler *hndl)
* * unregister and free the handler itself
*
* Context: Assumes all the proper locking has been managed by the caller.
+ *
+ * Return: True if handler was freed (users dropped to zero)
*/
-static void scmi_put_handler_unlocked(struct scmi_notify_instance *ni,
+static bool scmi_put_handler_unlocked(struct scmi_notify_instance *ni,
struct scmi_event_handler *hndl)
{
+ bool freed = false;
+
if (refcount_dec_and_test(&hndl->users)) {
if (!IS_HNDL_PENDING(hndl))
scmi_disable_events(hndl);
scmi_free_event_handler(hndl);
+ freed = true;
}
+
+ return freed;
}
static void scmi_put_handler(struct scmi_notify_instance *ni,
struct scmi_event_handler *hndl)
{
+ bool freed;
+ u8 protocol_id;
struct scmi_registered_event *r_evt = hndl->r_evt;
mutex_lock(&ni->pending_mtx);
- if (r_evt)
+ if (r_evt) {
+ protocol_id = r_evt->proto->id;
mutex_lock(&r_evt->proto->registered_mtx);
+ }
- scmi_put_handler_unlocked(ni, hndl);
+ freed = scmi_put_handler_unlocked(ni, hndl);
- if (r_evt)
+ if (r_evt) {
mutex_unlock(&r_evt->proto->registered_mtx);
+ /*
+ * Only registered handler acquired protocol; must be here
+ * released only AFTER unlocking registered_mtx, since
+ * releasing a protocol can trigger its de-initialization
+ * (ie. including r_evt and registered_mtx)
+ */
+ if (freed)
+ scmi_release_protocol(ni->handle, protocol_id);
+ }
mutex_unlock(&ni->pending_mtx);
}
static void scmi_put_active_handler(struct scmi_notify_instance *ni,
struct scmi_event_handler *hndl)
{
+ bool freed;
struct scmi_registered_event *r_evt = hndl->r_evt;
+ u8 protocol_id = r_evt->proto->id;
mutex_lock(&r_evt->proto->registered_mtx);
- scmi_put_handler_unlocked(ni, hndl);
+ freed = scmi_put_handler_unlocked(ni, hndl);
mutex_unlock(&r_evt->proto->registered_mtx);
+ if (freed)
+ scmi_release_protocol(ni->handle, protocol_id);
}
/**
--
2.17.1
next prev parent reply other threads:[~2021-01-06 20:21 UTC|newest]
Thread overview: 50+ messages / expand[flat|nested] mbox.gz Atom feed top
2021-01-06 20:15 [PATCH v4 0/37] SCMI vendor protocols and modularization Cristian Marussi
2021-01-06 20:15 ` [PATCH v4 01/37] firmware: arm_scmi: review protocol registration interface Cristian Marussi
2021-01-06 20:15 ` [PATCH v4 02/37] firmware: arm_scmi: introduce protocol handle definitions Cristian Marussi
2021-01-07 14:29 ` Thara Gopinath
2021-01-08 12:04 ` Cristian Marussi
2021-01-08 15:50 ` Thara Gopinath
2021-01-06 20:15 ` [PATCH v4 03/37] firmware: arm_scmi: introduce devres get/put protocols operations Cristian Marussi
2021-01-07 14:28 ` Thara Gopinath
2021-01-08 12:24 ` Cristian Marussi
2021-01-08 13:42 ` Etienne Carriere
2021-01-08 16:42 ` Cristian Marussi
2021-01-06 20:15 ` [PATCH v4 04/37] [RFC] firmware: arm_scmi: introduce bare get/put protocols ops Cristian Marussi
2021-01-07 14:30 ` Thara Gopinath
2021-01-06 20:15 ` Cristian Marussi [this message]
2021-01-06 20:15 ` [PATCH v4 06/37] firmware: arm_scmi: introduce new devres notification ops Cristian Marussi
2021-01-06 20:15 ` [PATCH v4 07/37] firmware: arm_scmi: refactor events registration Cristian Marussi
2021-01-06 20:15 ` [PATCH v4 08/37] firmware: arm_scmi: convert events registration to protocol handles Cristian Marussi
2021-01-06 20:15 ` [PATCH v4 09/37] firmware: arm_scmi: add new protocol handle core xfer ops Cristian Marussi
2021-01-06 20:15 ` [PATCH v4 10/37] firmware: arm_scmi: add helper to access revision area memory Cristian Marussi
2021-01-06 20:15 ` [PATCH v4 11/37] firmware: arm_scmi: port Base protocol to new interface Cristian Marussi
2021-01-06 20:15 ` [PATCH v4 12/37] firmware: arm_scmi: port Perf protocol to new protocols interface Cristian Marussi
2021-01-06 20:15 ` [PATCH v4 13/37] cpufreq: scmi: port driver to the new scmi_perf_proto_ops interface Cristian Marussi
2021-01-06 20:15 ` [PATCH v4 14/37] firmware: arm_scmi: remove legacy scmi_perf_ops protocol interface Cristian Marussi
2021-01-06 20:15 ` [PATCH v4 15/37] firmware: arm_scmi: port Power protocol to new protocols interface Cristian Marussi
2021-01-06 20:15 ` [PATCH v4 16/37] firmware: arm_scmi: port GenPD driver to the new scmi_power_proto_ops interface Cristian Marussi
2021-01-06 20:15 ` [PATCH v4 17/37] firmware: arm_scmi: remove legacy scmi_power_ops protocol interface Cristian Marussi
2021-01-06 20:15 ` [PATCH v4 18/37] firmware: arm_scmi: port Clock protocol to new protocols interface Cristian Marussi
2021-01-06 20:15 ` [PATCH v4 19/37] clk: scmi: port driver to the new scmi_clk_proto_ops interface Cristian Marussi
2021-01-06 20:15 ` [PATCH v4 20/37] firmware: arm_scmi: remove legacy scmi_clk_ops protocol interface Cristian Marussi
2021-01-06 20:15 ` [PATCH v4 21/37] firmware: arm_scmi: port Reset protocol to new protocols interface Cristian Marussi
2021-01-06 20:15 ` [PATCH v4 22/37] reset: reset-scmi: port driver to the new scmi_reset_proto_ops interface Cristian Marussi
2021-01-06 20:15 ` [PATCH v4 23/37] firmware: arm_scmi: remove legacy scmi_reset_ops protocol interface Cristian Marussi
2021-01-06 20:15 ` [PATCH v4 24/37] firmware: arm_scmi: port Sensor protocol to new protocols interface Cristian Marussi
2021-01-06 20:15 ` [PATCH v4 25/37] hwmon: (scmi) port driver to the new scmi_sensor_proto_ops interface Cristian Marussi
2021-01-06 20:15 ` [PATCH v4 26/37] firmware: arm_scmi: remove legacy scmi_sensor_ops protocol interface Cristian Marussi
2021-01-06 20:16 ` [PATCH v4 27/37] firmware: arm_scmi: port SystemPower protocol to new protocols interface Cristian Marussi
2021-01-06 20:16 ` [PATCH v4 28/37] firmware: arm_scmi: port Voltage " Cristian Marussi
2021-01-06 20:16 ` [PATCH v4 29/37] regulator: scmi: port driver to the new scmi_voltage_proto_ops interface Cristian Marussi
2021-01-06 20:16 ` [PATCH v4 30/37] firmware: arm_scmi: remove legacy scmi_voltage_ops protocol interface Cristian Marussi
2021-01-06 20:16 ` [PATCH v4 31/37] firmware: arm_scmi: make references to handle const Cristian Marussi
2021-01-06 20:16 ` [PATCH v4 32/37] firmware: arm_scmi: cleanup legacy protocol init code Cristian Marussi
2021-01-06 20:16 ` [PATCH v4 33/37] firmware: arm_scmi: cleanup unused core xfer wrappers Cristian Marussi
2021-01-06 20:16 ` [PATCH v4 34/37] firmware: arm_scmi: cleanup events registration transient code Cristian Marussi
2021-01-06 20:16 ` [PATCH v4 35/37] firmware: arm_scmi: make notify_priv really private Cristian Marussi
2021-01-06 20:16 ` [PATCH v4 36/37] firmware: arm_scmi: add protocol modularization support Cristian Marussi
2021-01-06 20:16 ` [PATCH v4 37/37] firmware: arm_scmi: add dynamic scmi devices creation Cristian Marussi
2021-01-07 14:28 ` Thara Gopinath
2021-01-08 14:42 ` Cristian Marussi
2021-01-08 16:32 ` Thara Gopinath
2021-01-08 16:52 ` Cristian Marussi
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