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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 v2 8/8] firmware: arm_scmi: add protocol modularization support
Date: Wed, 28 Oct 2020 20:29:14 +0000	[thread overview]
Message-ID: <20201028202914.43662-9-cristian.marussi@arm.com> (raw)
In-Reply-To: <20201028202914.43662-1-cristian.marussi@arm.com>

Extend SCMI protocols accounting to address possible module usage and add
the support to possibly define new protocols as loadable modules.
Keep Standard protocols built into the SCMI core.

Signed-off-by: Cristian Marussi <cristian.marussi@arm.com>
---
 drivers/firmware/arm_scmi/base.c    |  2 ++
 drivers/firmware/arm_scmi/bus.c     | 11 ++++++++++-
 drivers/firmware/arm_scmi/clock.c   |  2 ++
 drivers/firmware/arm_scmi/common.h  |  4 ++++
 drivers/firmware/arm_scmi/driver.c  |  5 ++++-
 drivers/firmware/arm_scmi/perf.c    |  2 ++
 drivers/firmware/arm_scmi/power.c   |  2 ++
 drivers/firmware/arm_scmi/reset.c   |  2 ++
 drivers/firmware/arm_scmi/sensors.c |  2 ++
 drivers/firmware/arm_scmi/system.c  |  2 ++
 include/linux/scmi_protocol.h       | 12 ++++++++++++
 11 files changed, 44 insertions(+), 2 deletions(-)

diff --git a/drivers/firmware/arm_scmi/base.c b/drivers/firmware/arm_scmi/base.c
index 745e475e6cc4..e66e23d07d82 100644
--- a/drivers/firmware/arm_scmi/base.c
+++ b/drivers/firmware/arm_scmi/base.c
@@ -7,6 +7,7 @@
 
 #define pr_fmt(fmt) "SCMI Notifications BASE - " fmt
 
+#include <linux/module.h>
 #include <linux/scmi_protocol.h>
 
 #include "common.h"
@@ -373,6 +374,7 @@ static int scmi_base_protocol_init(const struct scmi_protocol_handle *ph)
 
 static const struct scmi_protocol scmi_base = {
 	.id = SCMI_PROTOCOL_BASE,
+	.owner = NULL,
 	.init = &scmi_base_protocol_init,
 	.ops = NULL,
 	.events = &base_protocol_events,
diff --git a/drivers/firmware/arm_scmi/bus.c b/drivers/firmware/arm_scmi/bus.c
index 25b191cfefc1..b152860f6c99 100644
--- a/drivers/firmware/arm_scmi/bus.c
+++ b/drivers/firmware/arm_scmi/bus.c
@@ -56,7 +56,7 @@ const struct scmi_protocol *scmi_get_protocol(int protocol_id)
 	const struct scmi_protocol *proto;
 
 	proto = idr_find(&scmi_available_protocols, protocol_id);
-	if (!proto) {
+	if (!proto || !try_module_get(proto->owner)) {
 		pr_warn("SCMI Protocol 0x%x not found!\n", protocol_id);
 		return NULL;
 	}
@@ -66,6 +66,15 @@ const struct scmi_protocol *scmi_get_protocol(int protocol_id)
 	return proto;
 }
 
+void scmi_put_protocol(int protocol_id)
+{
+	const struct scmi_protocol *proto;
+
+	proto = idr_find(&scmi_available_protocols, protocol_id);
+	if (proto)
+		module_put(proto->owner);
+}
+
 static int scmi_dev_probe(struct device *dev)
 {
 	struct scmi_driver *scmi_drv = to_scmi_driver(dev->driver);
diff --git a/drivers/firmware/arm_scmi/clock.c b/drivers/firmware/arm_scmi/clock.c
index 00041dcb4d06..06ed45c0002a 100644
--- a/drivers/firmware/arm_scmi/clock.c
+++ b/drivers/firmware/arm_scmi/clock.c
@@ -5,6 +5,7 @@
  * Copyright (C) 2018-2020 ARM Ltd.
  */
 
+#include <linux/module.h>
 #include <linux/sort.h>
 
 #include "common.h"
@@ -367,6 +368,7 @@ static int scmi_clock_protocol_init(const struct scmi_protocol_handle *ph)
 
 static const struct scmi_protocol scmi_clock = {
 	.id = SCMI_PROTOCOL_CLOCK,
+	.owner = THIS_MODULE,
 	.init = &scmi_clock_protocol_init,
 	.ops = &clk_ops,
 };
diff --git a/drivers/firmware/arm_scmi/common.h b/drivers/firmware/arm_scmi/common.h
index 9ae0e4133f31..d3f62f85ea18 100644
--- a/drivers/firmware/arm_scmi/common.h
+++ b/drivers/firmware/arm_scmi/common.h
@@ -14,6 +14,7 @@
 #include <linux/device.h>
 #include <linux/errno.h>
 #include <linux/kernel.h>
+#include <linux/module.h>
 #include <linux/scmi_protocol.h>
 #include <linux/types.h>
 
@@ -216,6 +217,7 @@ typedef int (*scmi_prot_init_fn_t)(const struct scmi_protocol_handle *);
 /**
  * struct scmi_protocol  - Protocol descriptor
  * @id: Protocol ID.
+ * @owner: Module reference if any.
  * @init: Mandatory protocol initialization function.
  * @deinit: Optional protocol de-initialization function.
  * @ops: Optional reference to the operations provided by the protocol and
@@ -224,6 +226,7 @@ typedef int (*scmi_prot_init_fn_t)(const struct scmi_protocol_handle *);
  */
 struct scmi_protocol {
 	const u8				id;
+	struct module				*owner;
 	const scmi_prot_init_fn_t		init;
 	const scmi_prot_init_fn_t		deinit;
 	const void				*ops;
@@ -256,6 +259,7 @@ void __exit scmi_##name##_unregister(void) \
 }
 
 const struct scmi_protocol *scmi_get_protocol(int protocol_id);
+void scmi_put_protocol(int protocol_id);
 
 int scmi_acquire_protocol(const struct scmi_handle *handle, u8 protocol_id);
 void scmi_release_protocol(const struct scmi_handle *handle, u8 protocol_id);
diff --git a/drivers/firmware/arm_scmi/driver.c b/drivers/firmware/arm_scmi/driver.c
index d6a975992136..077152fd5fc3 100644
--- a/drivers/firmware/arm_scmi/driver.c
+++ b/drivers/firmware/arm_scmi/driver.c
@@ -677,7 +677,7 @@ scmi_get_protocol_instance(const struct scmi_handle *handle, u8 protocol_id)
 		/* Fail if protocol not registered on bus */
 		proto = scmi_get_protocol(protocol_id);
 		if (!proto) {
-			ret = -ENODEV;
+			ret = -EPROBE_DEFER;
 			goto out;
 		}
 
@@ -722,6 +722,7 @@ scmi_get_protocol_instance(const struct scmi_handle *handle, u8 protocol_id)
 	return pi;
 
 clean:
+	scmi_put_protocol(protocol_id);
 	devres_release_group(handle->dev, gid);
 out:
 	mutex_unlock(&info->protocols_mtx);
@@ -772,6 +773,8 @@ void scmi_release_protocol(const struct scmi_handle *handle, u8 protocol_id)
 
 		idr_remove(&info->protocols, protocol_id);
 
+		scmi_put_protocol(protocol_id);
+
 		devres_release_group(handle->dev, gid);
 		dev_dbg(handle->dev, "De-Initialized protocol: 0x%X\n",
 			protocol_id);
diff --git a/drivers/firmware/arm_scmi/perf.c b/drivers/firmware/arm_scmi/perf.c
index c1d0664aaf4a..66e0d2364ea6 100644
--- a/drivers/firmware/arm_scmi/perf.c
+++ b/drivers/firmware/arm_scmi/perf.c
@@ -11,6 +11,7 @@
 #include <linux/of.h>
 #include <linux/io.h>
 #include <linux/io-64-nonatomic-hi-lo.h>
+#include <linux/module.h>
 #include <linux/platform_device.h>
 #include <linux/pm_opp.h>
 #include <linux/scmi_protocol.h>
@@ -900,6 +901,7 @@ static int scmi_perf_protocol_init(const struct scmi_protocol_handle *ph)
 
 static const struct scmi_protocol scmi_perf = {
 	.id = SCMI_PROTOCOL_PERF,
+	.owner = THIS_MODULE,
 	.init = &scmi_perf_protocol_init,
 	.ops = &perf_ops,
 	.events = &perf_protocol_events,
diff --git a/drivers/firmware/arm_scmi/power.c b/drivers/firmware/arm_scmi/power.c
index d9ce794d0299..819d948eb034 100644
--- a/drivers/firmware/arm_scmi/power.c
+++ b/drivers/firmware/arm_scmi/power.c
@@ -7,6 +7,7 @@
 
 #define pr_fmt(fmt) "SCMI Notifications POWER - " fmt
 
+#include <linux/module.h>
 #include <linux/scmi_protocol.h>
 
 #include "common.h"
@@ -310,6 +311,7 @@ static int scmi_power_protocol_init(const struct scmi_protocol_handle *ph)
 
 static const struct scmi_protocol scmi_power = {
 	.id = SCMI_PROTOCOL_POWER,
+	.owner = THIS_MODULE,
 	.init = &scmi_power_protocol_init,
 	.ops = &power_ops,
 	.events = &power_protocol_events,
diff --git a/drivers/firmware/arm_scmi/reset.c b/drivers/firmware/arm_scmi/reset.c
index a183518baf18..9f408070b70d 100644
--- a/drivers/firmware/arm_scmi/reset.c
+++ b/drivers/firmware/arm_scmi/reset.c
@@ -7,6 +7,7 @@
 
 #define pr_fmt(fmt) "SCMI Notifications RESET - " fmt
 
+#include <linux/module.h>
 #include <linux/scmi_protocol.h>
 
 #include "common.h"
@@ -324,6 +325,7 @@ static int scmi_reset_protocol_init(const struct scmi_protocol_handle *ph)
 
 static const struct scmi_protocol scmi_reset = {
 	.id = SCMI_PROTOCOL_RESET,
+	.owner = THIS_MODULE,
 	.init = &scmi_reset_protocol_init,
 	.ops = &reset_ops,
 	.events = &reset_protocol_events,
diff --git a/drivers/firmware/arm_scmi/sensors.c b/drivers/firmware/arm_scmi/sensors.c
index a74a7938cd78..170d97f09d91 100644
--- a/drivers/firmware/arm_scmi/sensors.c
+++ b/drivers/firmware/arm_scmi/sensors.c
@@ -7,6 +7,7 @@
 
 #define pr_fmt(fmt) "SCMI Notifications SENSOR - " fmt
 
+#include <linux/module.h>
 #include <linux/scmi_protocol.h>
 
 #include "common.h"
@@ -375,6 +376,7 @@ static int scmi_sensors_protocol_init(const struct scmi_protocol_handle *ph)
 
 static const struct scmi_protocol scmi_sensors = {
 	.id = SCMI_PROTOCOL_SENSOR,
+	.owner = THIS_MODULE,
 	.init = &scmi_sensors_protocol_init,
 	.ops = &sensor_ops,
 	.events = &sensor_protocol_events,
diff --git a/drivers/firmware/arm_scmi/system.c b/drivers/firmware/arm_scmi/system.c
index 23365ef334bf..13bd223feb84 100644
--- a/drivers/firmware/arm_scmi/system.c
+++ b/drivers/firmware/arm_scmi/system.c
@@ -7,6 +7,7 @@
 
 #define pr_fmt(fmt) "SCMI Notifications SYSTEM - " fmt
 
+#include <linux/module.h>
 #include <linux/scmi_protocol.h>
 
 #include "common.h"
@@ -129,6 +130,7 @@ static int scmi_system_protocol_init(const struct scmi_protocol_handle *ph)
 
 static const struct scmi_protocol scmi_system = {
 	.id = SCMI_PROTOCOL_SYSTEM,
+	.owner = THIS_MODULE,
 	.init = &scmi_system_protocol_init,
 	.ops = NULL,
 	.events = &system_protocol_events,
diff --git a/include/linux/scmi_protocol.h b/include/linux/scmi_protocol.h
index 66625aedd3a7..7d6a12baa254 100644
--- a/include/linux/scmi_protocol.h
+++ b/include/linux/scmi_protocol.h
@@ -378,6 +378,18 @@ static inline void scmi_driver_unregister(struct scmi_driver *driver) {}
 #define module_scmi_driver(__scmi_driver)	\
 	module_driver(__scmi_driver, scmi_register, scmi_unregister)
 
+/**
+ * module_scmi_protocol() - Helper macro for registering a scmi protocol
+ * @__scmi_protocol: scmi_protocol structure
+ *
+ * Helper macro for scmi drivers to set up proper module init / exit
+ * functions.  Replaces module_init() and module_exit() and keeps people from
+ * printing pointless things to the kernel log when their driver is loaded.
+ */
+#define module_scmi_protocol(__scmi_protocol)	\
+	module_driver(__scmi_protocol,		\
+		      scmi_protocol_register, scmi_protocol_unregister)
+
 struct scmi_protocol;
 int scmi_protocol_register(const struct scmi_protocol *proto);
 void scmi_protocol_unregister(const struct scmi_protocol *proto);
-- 
2.17.1


  parent reply	other threads:[~2020-10-28 21:49 UTC|newest]

Thread overview: 21+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2020-10-28 20:29 [PATCH v2 0/8] SCMI vendor protocols and modularization Cristian Marussi
2020-10-28 20:29 ` [PATCH v2 1/8] firmware: arm_scmi: review protocol registration interface Cristian Marussi
2020-11-04 16:16   ` Thara Gopinath
2020-11-04 16:56     ` Cristian Marussi
2020-11-06 16:22       ` Thara Gopinath
2020-10-28 20:29 ` [PATCH v2 2/8] firmware: arm_scmi: introduce protocol handles Cristian Marussi
2020-11-04 16:16   ` Thara Gopinath
2020-11-04 16:58     ` Etienne Carriere
2020-11-04 17:44     ` Cristian Marussi
2020-11-06 16:26       ` Thara Gopinath
2020-11-07 12:53         ` Cristian Marussi
2020-10-28 20:29 ` [PATCH v2 3/8] firmware: arm_scmi: introduce new protocol operations support Cristian Marussi
2020-11-04 16:16   ` Thara Gopinath
2020-11-04 18:08     ` Cristian Marussi
2020-11-06 16:07       ` Thara Gopinath
2020-10-28 20:29 ` [PATCH v2 4/8] firmware: arm_scmi: make notifications aware of protocol usage Cristian Marussi
2020-10-28 20:29 ` [PATCH v2 5/8] firmware: arm_scmi: refactor events registration Cristian Marussi
2020-10-28 20:29 ` [PATCH v2 6/8] firmware: arm_scmi: port all protocols and drivers to the new API Cristian Marussi
2020-10-28 20:29 ` [PATCH v2 7/8] firmware: arm_scmi: make notify_priv really private Cristian Marussi
2020-10-28 20:29 ` Cristian Marussi [this message]
2020-11-04 16:15 ` [PATCH v2 0/8] SCMI vendor protocols and modularization Thara Gopinath

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