[PATCH v2 0/6] hwspinlock: allow sharing of hwspinlocks

[PATCH v2 0/6] hwspinlock: allow sharing of hwspinlocks

[Fabien Dessenne]

The current implementation does not allow two different devices to use
a common hwspinlock. This patch set proposes to have, as an option, some
hwspinlocks shared between several users.

Below is an example that explain the need for this:
	exti: interrupt-controller@5000d000 {
		compatible = "st,stm32mp1-exti", "syscon";
		interrupt-controller;
		#interrupt-cells = <2>;
		reg = <0x5000d000 0x400>;
		hwlocks = <&hsem 1>;
	};
The two drivers (stm32mp1-exti and syscon) refer to the same hwlock.
With the current hwspinlock implementation, only the first driver succeeds
in requesting (hwspin_lock_request_specific) the hwlock. The second request
fails.


The proposed approach does not modify the API, but extends the DT 'hwlocks'
property with a second optional parameter (the first one identifies an
hwlock) that specifies whether an hwlock is requested for exclusive usage
(current behavior) or can be shared between several users.
Examples:
	hwlocks = <&hsem 8>;	Ref to hwlock #8 for exclusive usage
	hwlocks = <&hsem 8 0>;	Ref to hwlock #8 for exclusive (0) usage
	hwlocks = <&hsem 8 1>;	Ref to hwlock #8 for shared (1) usage

As a constraint, the #hwlock-cells value must be 1 or 2.
In the current implementation, this can have theorically any value but:
- all of the exisiting drivers use the same value : 1.
- the framework supports only one value : 1 (see implementation of
  of_hwspin_lock_simple_xlate())
Hence, it shall not be a problem to restrict this value to 1 or 2 since
it won't break any driver.

Changes since v1:
* Removed useless 'status = "okay"' from stm32mp157c.dtsi

Fabien Dessenne (6):
  dt-bindings: hwlock: add support of shared locks
  hwspinlock: allow sharing of hwspinlocks
  dt-bindings: hwlock: update STM32 #hwlock-cells value
  ARM: dts: stm32: Add hwspinlock node for stm32mp157 SoC
  ARM: dts: stm32: Add hwlock for irqchip on stm32mp157
  ARM: dts: stm32: hwlocks for GPIO for stm32mp157

 .../devicetree/bindings/hwlock/hwlock.txt          | 27 +++++--
 .../bindings/hwlock/st,stm32-hwspinlock.txt        |  6 +-
 Documentation/hwspinlock.txt                       | 10 ++-
 arch/arm/boot/dts/stm32mp157-pinctrl.dtsi          |  2 +
 arch/arm/boot/dts/stm32mp157c.dtsi                 |  9 +++
 drivers/hwspinlock/hwspinlock_core.c               | 82 +++++++++++++++++-----
 drivers/hwspinlock/hwspinlock_internal.h           |  2 +
 7 files changed, 107 insertions(+), 31 deletions(-)

-- 
2.7.4

[PATCH v2 1/6] dt-bindings: hwlock: add support of shared locks

[Fabien Dessenne]

Use #hwlock-cells value to define whether the locks can be shared
by several users.

Signed-off-by: Fabien Dessenne <fabien.dessenne@st.com>
Reviewed-by: Rob Herring <robh@kernel.org>
---
 .../devicetree/bindings/hwlock/hwlock.txt          | 27 ++++++++++++++++------
 1 file changed, 20 insertions(+), 7 deletions(-)

diff --git a/Documentation/devicetree/bindings/hwlock/hwlock.txt b/Documentation/devicetree/bindings/hwlock/hwlock.txt
index 085d1f5..e98088a 100644
--- a/Documentation/devicetree/bindings/hwlock/hwlock.txt
+++ b/Documentation/devicetree/bindings/hwlock/hwlock.txt
@@ -13,7 +13,7 @@ hwlock providers:
 
 Required properties:
 - #hwlock-cells:        Specifies the number of cells needed to represent a
-                        specific lock.
+                        specific lock. Shall be 1 or 2 (see hwlocks below).
 
 hwlock users:
 =============
@@ -27,6 +27,11 @@ Required properties:
                         #hwlock-cells. The list can have just a single hwlock
                         or multiple hwlocks, with each hwlock represented by
                         a phandle and a corresponding args specifier.
+                        If #hwlock-cells is 1, all of the locks are exclusive
+                        (cannot be used by several users).
+                        If #hwlock-cells is 2, the value of the second cell
+                        defines whether the lock is for exclusive usage (0) or
+                        shared (1) i.e. can be used by several users.
 
 Optional properties:
 - hwlock-names:         List of hwlock name strings defined in the same order
@@ -46,14 +51,22 @@ of length 1.
 		...
 	};
 
-2. Example of a node using multiple specific hwlocks:
+2. Example of nodes using multiple and shared specific hwlocks:
 
-The following example has a node requesting two hwlocks, a hwlock within
-the hwlock device node 'hwlock1' with #hwlock-cells value of 1, and another
-hwlock within the hwlock device node 'hwlock2' with #hwlock-cells value of 2.
+The following example has a nodeA requesting two hwlocks:
+- an exclusive one (#hwlock-cells = 1) within the hwlock device node 'hwlock1'
+- a shared one (#hwlock-cells = 2, second cell = 1) within the hwlock device
+  node 'hwlock2'.
+The shared lock is also be used by nodeB.
 
-	node {
+	nodeA {
 		...
-		hwlocks = <&hwlock1 2>, <&hwlock2 0 3>;
+		hwlocks = <&hwlock1 2>, <&hwlock2 0 1>;
 		...
 	};
+
+	nodeB {
+		...
+		hwlocks = <&hwlock2 0 1>;
+		...
+	};
\ No newline at end of file
-- 
2.7.4

[PATCH v2 2/6] hwspinlock: allow sharing of hwspinlocks

[Fabien Dessenne]

The current implementation does not allow different devices to use a
common hwspinlock. Offer the possibility to use the same hwspinlock by
several users.
If a device registers to the framework with #hwlock-cells = 2, then
the second parameter of the 'hwlocks' DeviceTree property defines
whether an hwlock is requested for an exclusive or a shared usage.
If a device registers with #hwlock-cells = 1, then all the hwlocks are
for an exclusive usage.

Signed-off-by: Fabien Dessenne <fabien.dessenne@st.com>
---
 Documentation/hwspinlock.txt             | 10 ++--
 drivers/hwspinlock/hwspinlock_core.c     | 82 +++++++++++++++++++++++++-------
 drivers/hwspinlock/hwspinlock_internal.h |  2 +
 3 files changed, 73 insertions(+), 21 deletions(-)

diff --git a/Documentation/hwspinlock.txt b/Documentation/hwspinlock.txt
index ed640a2..e6ce2dd 100644
--- a/Documentation/hwspinlock.txt
+++ b/Documentation/hwspinlock.txt
@@ -54,9 +54,11 @@ Should be called from a process context (might sleep).
   struct hwspinlock *hwspin_lock_request_specific(unsigned int id);
 
 Assign a specific hwspinlock id and return its address, or NULL
-if that hwspinlock is already in use. Usually board code will
-be calling this function in order to reserve specific hwspinlock
-ids for predefined purposes.
+if that hwspinlock is already in use and not shared. If that specific
+hwspinlock is declared as shared, it can be requested and used by
+several users.
+Usually board code will be calling this function in order to reserve
+specific hwspinlock ids for predefined purposes.
 
 Should be called from a process context (might sleep).
 
@@ -368,11 +370,13 @@ of which represents a single hardware lock::
 	* struct hwspinlock - this struct represents a single hwspinlock instance
 	* @bank: the hwspinlock_device structure which owns this lock
 	* @lock: initialized and used by hwspinlock core
+	* @refcount: number of users (when shared)
 	* @priv: private data, owned by the underlying platform-specific hwspinlock drv
 	*/
 	struct hwspinlock {
 		struct hwspinlock_device *bank;
 		spinlock_t lock;
+		unsigned int refcount;
 		void *priv;
 	};
 
diff --git a/drivers/hwspinlock/hwspinlock_core.c b/drivers/hwspinlock/hwspinlock_core.c
index 2bad40d..53afdeb 100644
--- a/drivers/hwspinlock/hwspinlock_core.c
+++ b/drivers/hwspinlock/hwspinlock_core.c
@@ -25,6 +25,8 @@
 
 /* radix tree tags */
 #define HWSPINLOCK_UNUSED	(0) /* tags an hwspinlock as unused */
+#define HWSPINLOCK_EXCLUSIVE	(1) /* tags an hwspinlock as exclusive */
+#define HWSPINLOCK_SHARED	(2) /* tags an hwspinlock as shared */
 
 /*
  * A radix tree is used to maintain the available hwspinlock instances.
@@ -291,7 +293,7 @@ EXPORT_SYMBOL_GPL(__hwspin_unlock);
  * @hwlock_spec: hwlock specifier as found in the device tree
  *
  * This is a simple translation function, suitable for hwspinlock platform
- * drivers that only has a lock specifier length of 1.
+ * drivers that only has a lock specifier length of 1 or 2.
  *
  * Returns a relative index of the lock within a specified bank on success,
  * or -EINVAL on invalid specifier cell count.
@@ -299,7 +301,8 @@ EXPORT_SYMBOL_GPL(__hwspin_unlock);
 static inline int
 of_hwspin_lock_simple_xlate(const struct of_phandle_args *hwlock_spec)
 {
-	if (WARN_ON(hwlock_spec->args_count != 1))
+	if (WARN_ON(hwlock_spec->args_count != 1 &&
+		    hwlock_spec->args_count != 2))
 		return -EINVAL;
 
 	return hwlock_spec->args[0];
@@ -322,11 +325,12 @@ of_hwspin_lock_simple_xlate(const struct of_phandle_args *hwlock_spec)
 int of_hwspin_lock_get_id(struct device_node *np, int index)
 {
 	struct of_phandle_args args;
-	struct hwspinlock *hwlock;
+	struct hwspinlock *hwlock, *tmp;
 	struct radix_tree_iter iter;
 	void **slot;
 	int id;
 	int ret;
+	unsigned int tag;
 
 	ret = of_parse_phandle_with_args(np, "hwlocks", "#hwlock-cells", index,
 					 &args);
@@ -361,6 +365,37 @@ int of_hwspin_lock_get_id(struct device_node *np, int index)
 	}
 	id += hwlock->bank->base_id;
 
+	/* Set the EXCLUSIVE / SHARED tag */
+	if (args.args_count == 2 && args.args[1]) {
+		/* Tag SHARED unless already tagged EXCLUSIVE */
+		if (radix_tree_tag_get(&hwspinlock_tree, id,
+				       HWSPINLOCK_EXCLUSIVE)) {
+			ret = -EINVAL;
+			goto out;
+		}
+		tag = HWSPINLOCK_SHARED;
+	} else {
+		/* Tag EXCLUSIVE unless already tagged SHARED */
+		if (radix_tree_tag_get(&hwspinlock_tree, id,
+				       HWSPINLOCK_SHARED)) {
+			ret = -EINVAL;
+			goto out;
+		}
+		tag = HWSPINLOCK_EXCLUSIVE;
+	}
+
+	/* mark this hwspinlock */
+	hwlock = radix_tree_lookup(&hwspinlock_tree, id);
+	if (!hwlock) {
+		ret = -EINVAL;
+		goto out;
+	}
+
+	tmp = radix_tree_tag_set(&hwspinlock_tree, id, tag);
+
+	/* self-sanity check which should never fail */
+	WARN_ON(tmp != hwlock);
+
 out:
 	of_node_put(args.np);
 	return ret ? ret : id;
@@ -483,6 +518,7 @@ int hwspin_lock_register(struct hwspinlock_device *bank, struct device *dev,
 
 		spin_lock_init(&hwlock->lock);
 		hwlock->bank = bank;
+		hwlock->refcount = 0;
 
 		ret = hwspin_lock_register_single(hwlock, base_id + i);
 		if (ret)
@@ -625,7 +661,7 @@ static int __hwspin_lock_request(struct hwspinlock *hwlock)
 {
 	struct device *dev = hwlock->bank->dev;
 	struct hwspinlock *tmp;
-	int ret;
+	int ret, id;
 
 	/* prevent underlying implementation from being removed */
 	if (!try_module_get(dev->driver->owner)) {
@@ -642,13 +678,18 @@ static int __hwspin_lock_request(struct hwspinlock *hwlock)
 		return ret;
 	}
 
+	/* update shareable refcount */
+	id = hwlock_to_id(hwlock);
+	if (radix_tree_tag_get(&hwspinlock_tree, id, HWSPINLOCK_SHARED) &&
+	    hwlock->refcount++)
+		goto out;
+
 	/* mark hwspinlock as used, should not fail */
-	tmp = radix_tree_tag_clear(&hwspinlock_tree, hwlock_to_id(hwlock),
-							HWSPINLOCK_UNUSED);
+	tmp = radix_tree_tag_clear(&hwspinlock_tree, id, HWSPINLOCK_UNUSED);
 
 	/* self-sanity check that should never fail */
 	WARN_ON(tmp != hwlock);
-
+out:
 	return ret;
 }
 
@@ -742,9 +783,9 @@ struct hwspinlock *hwspin_lock_request_specific(unsigned int id)
 	/* sanity check (this shouldn't happen) */
 	WARN_ON(hwlock_to_id(hwlock) != id);
 
-	/* make sure this hwspinlock is unused */
-	ret = radix_tree_tag_get(&hwspinlock_tree, id, HWSPINLOCK_UNUSED);
-	if (ret == 0) {
+	/* make sure this hwspinlock is unused or shareable */
+	if (!radix_tree_tag_get(&hwspinlock_tree, id, HWSPINLOCK_SHARED) &&
+	    !radix_tree_tag_get(&hwspinlock_tree, id, HWSPINLOCK_UNUSED)) {
 		pr_warn("hwspinlock %u is already in use\n", id);
 		hwlock = NULL;
 		goto out;
@@ -777,7 +818,7 @@ int hwspin_lock_free(struct hwspinlock *hwlock)
 {
 	struct device *dev;
 	struct hwspinlock *tmp;
-	int ret;
+	int ret, id;
 
 	if (!hwlock) {
 		pr_err("invalid hwlock\n");
@@ -788,30 +829,35 @@ int hwspin_lock_free(struct hwspinlock *hwlock)
 	mutex_lock(&hwspinlock_tree_lock);
 
 	/* make sure the hwspinlock is used */
-	ret = radix_tree_tag_get(&hwspinlock_tree, hwlock_to_id(hwlock),
-							HWSPINLOCK_UNUSED);
+	id = hwlock_to_id(hwlock);
+	ret = radix_tree_tag_get(&hwspinlock_tree, id, HWSPINLOCK_UNUSED);
 	if (ret == 1) {
 		dev_err(dev, "%s: hwlock is already free\n", __func__);
 		dump_stack();
 		ret = -EINVAL;
-		goto out;
+		goto unlock;
 	}
 
 	/* notify the underlying device that power is not needed */
 	ret = pm_runtime_put(dev);
 	if (ret < 0)
-		goto out;
+		goto unlock;
+
+	/* update shareable refcount */
+	if (radix_tree_tag_get(&hwspinlock_tree, id, HWSPINLOCK_SHARED) &&
+	    --hwlock->refcount)
+		goto put;
 
 	/* mark this hwspinlock as available */
-	tmp = radix_tree_tag_set(&hwspinlock_tree, hwlock_to_id(hwlock),
-							HWSPINLOCK_UNUSED);
+	tmp = radix_tree_tag_set(&hwspinlock_tree, id, HWSPINLOCK_UNUSED);
 
 	/* sanity check (this shouldn't happen) */
 	WARN_ON(tmp != hwlock);
 
+put:
 	module_put(dev->driver->owner);
 
-out:
+unlock:
 	mutex_unlock(&hwspinlock_tree_lock);
 	return ret;
 }
diff --git a/drivers/hwspinlock/hwspinlock_internal.h b/drivers/hwspinlock/hwspinlock_internal.h
index 9eb6bd0..c808e11 100644
--- a/drivers/hwspinlock/hwspinlock_internal.h
+++ b/drivers/hwspinlock/hwspinlock_internal.h
@@ -35,11 +35,13 @@ struct hwspinlock_ops {
  * struct hwspinlock - this struct represents a single hwspinlock instance
  * @bank: the hwspinlock_device structure which owns this lock
  * @lock: initialized and used by hwspinlock core
+ * @refcount: number of users (when shared)
  * @priv: private data, owned by the underlying platform-specific hwspinlock drv
  */
 struct hwspinlock {
 	struct hwspinlock_device *bank;
 	spinlock_t lock;
+	unsigned int refcount;
 	void *priv;
 };
 
-- 
2.7.4

[PATCH v2 3/6] dt-bindings: hwlock: update STM32 #hwlock-cells value

[Fabien Dessenne]

Use a value of 2, so users can share hwlocks.

Signed-off-by: Fabien Dessenne <fabien.dessenne@st.com>
Reviewed-by: Rob Herring <robh@kernel.org>
---
 Documentation/devicetree/bindings/hwlock/st,stm32-hwspinlock.txt | 6 +++---
 1 file changed, 3 insertions(+), 3 deletions(-)

diff --git a/Documentation/devicetree/bindings/hwlock/st,stm32-hwspinlock.txt b/Documentation/devicetree/bindings/hwlock/st,stm32-hwspinlock.txt
index adf4f000..60a3716 100644
--- a/Documentation/devicetree/bindings/hwlock/st,stm32-hwspinlock.txt
+++ b/Documentation/devicetree/bindings/hwlock/st,stm32-hwspinlock.txt
@@ -4,8 +4,8 @@ STM32 Hardware Spinlock Device Binding
 Required properties :
 - compatible : should be "st,stm32-hwspinlock".
 - reg : the register address of hwspinlock.
-- #hwlock-cells : hwlock users only use the hwlock id to represent a specific
-	hwlock, so the number of cells should be <1> here.
+- #hwlock-cells : should be <2> so the hwlock users use the hwlock id to
+	represent a specific hwlock and define its shared / exclusive attribute.
 - clock-names : Must contain "hsem".
 - clocks : Must contain a phandle entry for the clock in clock-names, see the
 	common clock bindings.
@@ -16,7 +16,7 @@ Please look at the generic hwlock binding for usage information for consumers,
 Example of hwlock provider:
 	hwspinlock@4c000000 {
 		compatible = "st,stm32-hwspinlock";
-		#hwlock-cells = <1>;
+		#hwlock-cells = <2>;
 		reg = <0x4c000000 0x400>;
 		clocks = <&rcc HSEM>;
 		clock-names = "hsem";
-- 
2.7.4

[PATCH v2 4/6] ARM: dts: stm32: Add hwspinlock node for stm32mp157 SoC

[Fabien Dessenne]

Declare hwspinlock device for stm32mp157 SoC

Signed-off-by: Fabien Dessenne <fabien.dessenne@st.com>
---
 arch/arm/boot/dts/stm32mp157c.dtsi | 8 ++++++++
 1 file changed, 8 insertions(+)

diff --git a/arch/arm/boot/dts/stm32mp157c.dtsi b/arch/arm/boot/dts/stm32mp157c.dtsi
index 105e21f..824d7e1 100644
--- a/arch/arm/boot/dts/stm32mp157c.dtsi
+++ b/arch/arm/boot/dts/stm32mp157c.dtsi
@@ -886,6 +886,14 @@
 			status = "disabled";
 		};
 
+		hsem: hwspinlock@4c000000 {
+			compatible = "st,stm32-hwspinlock";
+			#hwlock-cells = <2>;
+			reg = <0x4c000000 0x400>;
+			clocks = <&rcc HSEM>;
+			clock-names = "hsem";
+		};
+
 		ipcc: mailbox@4c001000 {
 			compatible = "st,stm32mp1-ipcc";
 			#mbox-cells = <1>;
-- 
2.7.4

[PATCH v2 5/6] ARM: dts: stm32: Add hwlock for irqchip on stm32mp157

[Fabien Dessenne]

Define a hwspinlock to be used by the irq controller driver and the
syscon driver.

Signed-off-by: Fabien Dessenne <fabien.dessenne@st.com>
---
 arch/arm/boot/dts/stm32mp157c.dtsi | 1 +
 1 file changed, 1 insertion(+)

diff --git a/arch/arm/boot/dts/stm32mp157c.dtsi b/arch/arm/boot/dts/stm32mp157c.dtsi
index 824d7e1..417bdf7 100644
--- a/arch/arm/boot/dts/stm32mp157c.dtsi
+++ b/arch/arm/boot/dts/stm32mp157c.dtsi
@@ -921,6 +921,7 @@
 			interrupt-controller;
 			#interrupt-cells = <2>;
 			reg = <0x5000d000 0x400>;
+			hwlocks = <&hsem 1 1>;
 		};
 
 		syscfg: syscon@50020000 {
-- 
2.7.4

[PATCH v2 6/6] ARM: dts: stm32: hwlocks for GPIO for stm32mp157

[Fabien Dessenne]

Declare a shared hwlock to be used by all gpio / pin controllers.

Signed-off-by: Fabien Dessenne <fabien.dessenne@st.com>
---
 arch/arm/boot/dts/stm32mp157-pinctrl.dtsi | 2 ++
 1 file changed, 2 insertions(+)

diff --git a/arch/arm/boot/dts/stm32mp157-pinctrl.dtsi b/arch/arm/boot/dts/stm32mp157-pinctrl.dtsi
index 6b3a9c6..9fd562a 100644
--- a/arch/arm/boot/dts/stm32mp157-pinctrl.dtsi
+++ b/arch/arm/boot/dts/stm32mp157-pinctrl.dtsi
@@ -14,6 +14,7 @@
 			ranges = <0 0x50002000 0xa400>;
 			interrupt-parent = <&exti>;
 			st,syscfg = <&exti 0x60 0xff>;
+			hwlocks = <&hsem 0 1>;
 			pins-are-numbered;
 
 			gpioa: gpio@50002000 {
@@ -424,6 +425,7 @@
 			pins-are-numbered;
 			interrupt-parent = <&exti>;
 			st,syscfg = <&exti 0x60 0xff>;
+			hwlocks = <&hsem 0 1>;
 
 			gpioz: gpio@54004000 {
 				gpio-controller;
-- 
2.7.4

Re: [PATCH v2 0/6] hwspinlock: allow sharing of hwspinlocks

[Fabien DESSENNE]

Hi


I Got Rob's Reviewed-by. Any further comments?


Fabien


On 25/04/2019 11:17 AM, Fabien Dessenne wrote:
> The current implementation does not allow two different devices to use
> a common hwspinlock. This patch set proposes to have, as an option, some
> hwspinlocks shared between several users.
>
> Below is an example that explain the need for this:
> 	exti: interrupt-controller@5000d000 {
> 		compatible = "st,stm32mp1-exti", "syscon";
> 		interrupt-controller;
> 		#interrupt-cells = <2>;
> 		reg = <0x5000d000 0x400>;
> 		hwlocks = <&hsem 1>;
> 	};
> The two drivers (stm32mp1-exti and syscon) refer to the same hwlock.
> With the current hwspinlock implementation, only the first driver succeeds
> in requesting (hwspin_lock_request_specific) the hwlock. The second request
> fails.
>
>
> The proposed approach does not modify the API, but extends the DT 'hwlocks'
> property with a second optional parameter (the first one identifies an
> hwlock) that specifies whether an hwlock is requested for exclusive usage
> (current behavior) or can be shared between several users.
> Examples:
> 	hwlocks = <&hsem 8>;	Ref to hwlock #8 for exclusive usage
> 	hwlocks = <&hsem 8 0>;	Ref to hwlock #8 for exclusive (0) usage
> 	hwlocks = <&hsem 8 1>;	Ref to hwlock #8 for shared (1) usage
>
> As a constraint, the #hwlock-cells value must be 1 or 2.
> In the current implementation, this can have theorically any value but:
> - all of the exisiting drivers use the same value : 1.
> - the framework supports only one value : 1 (see implementation of
>    of_hwspin_lock_simple_xlate())
> Hence, it shall not be a problem to restrict this value to 1 or 2 since
> it won't break any driver.
>
> Changes since v1:
> * Removed useless 'status = "okay"' from stm32mp157c.dtsi
>
> Fabien Dessenne (6):
>    dt-bindings: hwlock: add support of shared locks
>    hwspinlock: allow sharing of hwspinlocks
>    dt-bindings: hwlock: update STM32 #hwlock-cells value
>    ARM: dts: stm32: Add hwspinlock node for stm32mp157 SoC
>    ARM: dts: stm32: Add hwlock for irqchip on stm32mp157
>    ARM: dts: stm32: hwlocks for GPIO for stm32mp157
>
>   .../devicetree/bindings/hwlock/hwlock.txt          | 27 +++++--
>   .../bindings/hwlock/st,stm32-hwspinlock.txt        |  6 +-
>   Documentation/hwspinlock.txt                       | 10 ++-
>   arch/arm/boot/dts/stm32mp157-pinctrl.dtsi          |  2 +
>   arch/arm/boot/dts/stm32mp157c.dtsi                 |  9 +++
>   drivers/hwspinlock/hwspinlock_core.c               | 82 +++++++++++++++++-----
>   drivers/hwspinlock/hwspinlock_internal.h           |  2 +
>   7 files changed, 107 insertions(+), 31 deletions(-)
>