[PATCH v5 0/3] soc: ti: k3: Allow for exclusive and shared device requests

[PATCH v5 0/3] soc: ti: k3: Allow for exclusive and shared device requests

[Lokesh Vutla]

Sysfw provides an option for requesting exclusive access for a
device using the flags MSG_FLAG_DEVICE_EXCLUSIVE. If this flag is
not used, the device is meant to be shared across hosts. Once a device
is requested from a host with this flag set, any request to this
device from a different host will be nacked by sysfw.

Current tisci firmware and pm drivers always requests for device with
exclusive permissions set. But this is not be true for certain devices
that are expcted to be shared across different host contexts.
So add support for getting the shared or exclusive permissions from DT
and request firmware accordingly.

Changes since v4: https://patchwork.kernel.org/project/linux-arm-kernel/list/?series=148371
- Split the driver and arch changes into a separate series.
- Added Reviewed-by from Nishanth M
- Rebased on top of v5.3-rc2

Lokesh Vutla (3):
  firmware: ti_sci: Allow for device shared and exclusive requests
  dt-bindings: ti_sci_pm_domains: Add support for exclusive and shared
    access
  soc: ti: ti_sci_pm_domains: Add support for exclusive and shared
    access

 .../bindings/soc/ti/sci-pm-domain.txt         | 11 ++++-
 MAINTAINERS                                   |  1 +
 drivers/firmware/ti_sci.c                     | 45 ++++++++++++++++++-
 drivers/soc/ti/ti_sci_pm_domains.c            | 23 +++++++++-
 include/dt-bindings/soc/ti,sci_pm_domain.h    |  9 ++++
 include/linux/soc/ti/ti_sci_protocol.h        |  3 ++
 6 files changed, 86 insertions(+), 6 deletions(-)
 create mode 100644 include/dt-bindings/soc/ti,sci_pm_domain.h

-- 
2.21.0


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[PATCH v5 1/3] firmware: ti_sci: Allow for device shared and exclusive requests

[Lokesh Vutla]

Sysfw provides an option for requesting exclusive access for a
device using the flags MSG_FLAG_DEVICE_EXCLUSIVE. If this flag is
not used, the device is meant to be shared across hosts. Once a device
is requested from a host with this flag set, any request to this
device from a different host will be nacked by sysfw. Current tisci
driver enables this flag for every device requests. But this may not
be true for all the devices. So provide a separate commands in driver
for exclusive and shared device requests.

Reviewed-by: Nishanth Menon <nm@ti.com>
Signed-off-by: Lokesh Vutla <lokeshvutla@ti.com>
---
 drivers/firmware/ti_sci.c              | 45 ++++++++++++++++++++++++--
 include/linux/soc/ti/ti_sci_protocol.h |  3 ++
 2 files changed, 46 insertions(+), 2 deletions(-)

diff --git a/drivers/firmware/ti_sci.c b/drivers/firmware/ti_sci.c
index cdee0b45943d..4126be9e3216 100644
--- a/drivers/firmware/ti_sci.c
+++ b/drivers/firmware/ti_sci.c
@@ -635,6 +635,7 @@ static int ti_sci_get_device_state(const struct ti_sci_handle *handle,
 
 /**
  * ti_sci_cmd_get_device() - command to request for device managed by TISCI
+ *			     that can be shared with other hosts.
  * @handle:	Pointer to TISCI handle as retrieved by *ti_sci_get_handle
  * @id:		Device Identifier
  *
@@ -642,11 +643,29 @@ static int ti_sci_get_device_state(const struct ti_sci_handle *handle,
  * usage count by balancing get_device with put_device. No refcounting is
  * managed by driver for that purpose.
  *
- * NOTE: The request is for exclusive access for the processor.
- *
  * Return: 0 if all went fine, else return appropriate error.
  */
 static int ti_sci_cmd_get_device(const struct ti_sci_handle *handle, u32 id)
+{
+	return ti_sci_set_device_state(handle, id, 0,
+				       MSG_DEVICE_SW_STATE_ON);
+}
+
+/**
+ * ti_sci_cmd_get_device_exclusive() - command to request for device managed by
+ *				       TISCI that is exclusively owned by the
+ *				       requesting host.
+ * @handle:	Pointer to TISCI handle as retrieved by *ti_sci_get_handle
+ * @id:		Device Identifier
+ *
+ * Request for the device - NOTE: the client MUST maintain integrity of
+ * usage count by balancing get_device with put_device. No refcounting is
+ * managed by driver for that purpose.
+ *
+ * Return: 0 if all went fine, else return appropriate error.
+ */
+static int ti_sci_cmd_get_device_exclusive(const struct ti_sci_handle *handle,
+					   u32 id)
 {
 	return ti_sci_set_device_state(handle, id,
 				       MSG_FLAG_DEVICE_EXCLUSIVE,
@@ -665,6 +684,26 @@ static int ti_sci_cmd_get_device(const struct ti_sci_handle *handle, u32 id)
  * Return: 0 if all went fine, else return appropriate error.
  */
 static int ti_sci_cmd_idle_device(const struct ti_sci_handle *handle, u32 id)
+{
+	return ti_sci_set_device_state(handle, id, 0,
+				       MSG_DEVICE_SW_STATE_RETENTION);
+}
+
+/**
+ * ti_sci_cmd_idle_device_exclusive() - Command to idle a device managed by
+ *					TISCI that is exclusively owned by
+ *					requesting host.
+ * @handle:	Pointer to TISCI handle as retrieved by *ti_sci_get_handle
+ * @id:		Device Identifier
+ *
+ * Request for the device - NOTE: the client MUST maintain integrity of
+ * usage count by balancing get_device with put_device. No refcounting is
+ * managed by driver for that purpose.
+ *
+ * Return: 0 if all went fine, else return appropriate error.
+ */
+static int ti_sci_cmd_idle_device_exclusive(const struct ti_sci_handle *handle,
+					    u32 id)
 {
 	return ti_sci_set_device_state(handle, id,
 				       MSG_FLAG_DEVICE_EXCLUSIVE,
@@ -2894,7 +2933,9 @@ static void ti_sci_setup_ops(struct ti_sci_info *info)
 	core_ops->reboot_device = ti_sci_cmd_core_reboot;
 
 	dops->get_device = ti_sci_cmd_get_device;
+	dops->get_device_exclusive = ti_sci_cmd_get_device_exclusive;
 	dops->idle_device = ti_sci_cmd_idle_device;
+	dops->idle_device_exclusive = ti_sci_cmd_idle_device_exclusive;
 	dops->put_device = ti_sci_cmd_put_device;
 
 	dops->is_valid = ti_sci_cmd_dev_is_valid;
diff --git a/include/linux/soc/ti/ti_sci_protocol.h b/include/linux/soc/ti/ti_sci_protocol.h
index 6c610e188a44..9531ec823298 100644
--- a/include/linux/soc/ti/ti_sci_protocol.h
+++ b/include/linux/soc/ti/ti_sci_protocol.h
@@ -97,7 +97,10 @@ struct ti_sci_core_ops {
  */
 struct ti_sci_dev_ops {
 	int (*get_device)(const struct ti_sci_handle *handle, u32 id);
+	int (*get_device_exclusive)(const struct ti_sci_handle *handle, u32 id);
 	int (*idle_device)(const struct ti_sci_handle *handle, u32 id);
+	int (*idle_device_exclusive)(const struct ti_sci_handle *handle,
+				     u32 id);
 	int (*put_device)(const struct ti_sci_handle *handle, u32 id);
 	int (*is_valid)(const struct ti_sci_handle *handle, u32 id);
 	int (*get_context_loss_count)(const struct ti_sci_handle *handle,
-- 
2.21.0


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[PATCH v5 2/3] dt-bindings: ti_sci_pm_domains: Add support for exclusive and shared access

[Lokesh Vutla]

TISCI protocol supports for enabling the device either with exclusive
permissions for the requesting host or with sharing across the hosts.
There are certain devices which are exclusive to Linux context and
there are certain devices that are shared across different host contexts.
So add support for getting this information from DT by increasing
the power-domain cells to 2.

Acked-by: Tero Kristo <t-kristo@ti.com>
Acked-by: Rob Herring <robh@kernel.org>
Reviewed-by: Nishanth Menon <nm@ti.com>
Signed-off-by: Lokesh Vutla <lokeshvutla@ti.com>
---
 .../devicetree/bindings/soc/ti/sci-pm-domain.txt      | 11 +++++++++--
 MAINTAINERS                                           |  1 +
 include/dt-bindings/soc/ti,sci_pm_domain.h            |  9 +++++++++
 3 files changed, 19 insertions(+), 2 deletions(-)
 create mode 100644 include/dt-bindings/soc/ti,sci_pm_domain.h

diff --git a/Documentation/devicetree/bindings/soc/ti/sci-pm-domain.txt b/Documentation/devicetree/bindings/soc/ti/sci-pm-domain.txt
index f7b00a7c0f68..f541d1f776a2 100644
--- a/Documentation/devicetree/bindings/soc/ti/sci-pm-domain.txt
+++ b/Documentation/devicetree/bindings/soc/ti/sci-pm-domain.txt
@@ -19,8 +19,15 @@ child of the pmmc node.
 Required Properties:
 --------------------
 - compatible: should be "ti,sci-pm-domain"
-- #power-domain-cells: Must be 1 so that an id can be provided in each
-		       device node.
+- #power-domain-cells: Can be one of the following:
+			1: Containing the device id of each node
+			2: First entry should be device id
+			   Second entry should be one of the floowing:
+			   TI_SCI_PD_EXCLUSIVE: To allow device to be
+						exclusively controlled by
+						the requesting hosts.
+			   TI_SCI_PD_SHARED: To allow device to be shared
+					     by multiple hosts.
 
 Example (K2G):
 -------------
diff --git a/MAINTAINERS b/MAINTAINERS
index 6426db5198f0..fe7406427023 100644
--- a/MAINTAINERS
+++ b/MAINTAINERS
@@ -15853,6 +15853,7 @@ F:	drivers/firmware/ti_sci*
 F:	include/linux/soc/ti/ti_sci_protocol.h
 F:	Documentation/devicetree/bindings/soc/ti/sci-pm-domain.txt
 F:	drivers/soc/ti/ti_sci_pm_domains.c
+F:	include/dt-bindings/soc/ti,sci_pm_domain.h
 F:	Documentation/devicetree/bindings/reset/ti,sci-reset.txt
 F:	Documentation/devicetree/bindings/clock/ti,sci-clk.txt
 F:	drivers/clk/keystone/sci-clk.c
diff --git a/include/dt-bindings/soc/ti,sci_pm_domain.h b/include/dt-bindings/soc/ti,sci_pm_domain.h
new file mode 100644
index 000000000000..8f2a7360b65e
--- /dev/null
+++ b/include/dt-bindings/soc/ti,sci_pm_domain.h
@@ -0,0 +1,9 @@
+/* SPDX-License-Identifier: GPL-2.0 */
+
+#ifndef __DT_BINDINGS_TI_SCI_PM_DOMAIN_H
+#define __DT_BINDINGS_TI_SCI_PM_DOMAIN_H
+
+#define TI_SCI_PD_EXCLUSIVE	1
+#define TI_SCI_PD_SHARED	0
+
+#endif /* __DT_BINDINGS_TI_SCI_PM_DOMAIN_H */
-- 
2.21.0


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[PATCH v5 3/3] soc: ti: ti_sci_pm_domains: Add support for exclusive and shared access

[Lokesh Vutla]

TISCI protocol supports for enabling the device either with exclusive
permissions for the requesting host or with sharing across the hosts.
There are certain devices which are exclusive to Linux context and
there are certain devices that are shared across different host contexts.
So add support for getting this information from DT by increasing
the power-domain cells to 2.

For keeping the DT backward compatibility intact, defaulting the
device permissions to set the exclusive flag set. In this case the
power-domain-cells is 1.

Reviewed-by: Nishanth Menon <nm@ti.com>
Signed-off-by: Lokesh Vutla <lokeshvutla@ti.com>
---
 drivers/soc/ti/ti_sci_pm_domains.c | 23 +++++++++++++++++++++--
 1 file changed, 21 insertions(+), 2 deletions(-)

diff --git a/drivers/soc/ti/ti_sci_pm_domains.c b/drivers/soc/ti/ti_sci_pm_domains.c
index 97817dd7ba24..8c2a2f23982c 100644
--- a/drivers/soc/ti/ti_sci_pm_domains.c
+++ b/drivers/soc/ti/ti_sci_pm_domains.c
@@ -15,15 +15,19 @@
 #include <linux/pm_domain.h>
 #include <linux/slab.h>
 #include <linux/soc/ti/ti_sci_protocol.h>
+#include <dt-bindings/soc/ti,sci_pm_domain.h>
 
 /**
  * struct ti_sci_genpd_dev_data: holds data needed for every device attached
  *				 to this genpd
  * @idx: index of the device that identifies it with the system
  *	 control processor.
+ * @exclusive: Permissions for exclusive request or shared request of the
+ *	       device.
  */
 struct ti_sci_genpd_dev_data {
 	int idx;
+	u8 exclusive;
 };
 
 /**
@@ -55,6 +59,14 @@ static int ti_sci_dev_id(struct device *dev)
 	return sci_dev_data->idx;
 }
 
+static u8 is_ti_sci_dev_exclusive(struct device *dev)
+{
+	struct generic_pm_domain_data *genpd_data = dev_gpd_data(dev);
+	struct ti_sci_genpd_dev_data *sci_dev_data = genpd_data->data;
+
+	return sci_dev_data->exclusive;
+}
+
 /**
  * ti_sci_dev_to_sci_handle(): get pointer to ti_sci_handle
  * @dev: pointer to device associated with this genpd
@@ -79,7 +91,10 @@ static int ti_sci_dev_start(struct device *dev)
 	const struct ti_sci_handle *ti_sci = ti_sci_dev_to_sci_handle(dev);
 	int idx = ti_sci_dev_id(dev);
 
-	return ti_sci->ops.dev_ops.get_device(ti_sci, idx);
+	if (is_ti_sci_dev_exclusive(dev))
+		return ti_sci->ops.dev_ops.get_device_exclusive(ti_sci, idx);
+	else
+		return ti_sci->ops.dev_ops.get_device(ti_sci, idx);
 }
 
 /**
@@ -110,7 +125,7 @@ static int ti_sci_pd_attach_dev(struct generic_pm_domain *domain,
 	if (ret < 0)
 		return ret;
 
-	if (pd_args.args_count != 1)
+	if (pd_args.args_count != 1 && pd_args.args_count != 2)
 		return -EINVAL;
 
 	idx = pd_args.args[0];
@@ -128,6 +143,10 @@ static int ti_sci_pd_attach_dev(struct generic_pm_domain *domain,
 		return -ENOMEM;
 
 	sci_dev_data->idx = idx;
+	/* Enable the exclusive permissions by default */
+	sci_dev_data->exclusive = TI_SCI_PD_EXCLUSIVE;
+	if (pd_args.args_count == 2)
+		sci_dev_data->exclusive = pd_args.args[1] & 0x1;
 
 	genpd_data = dev_gpd_data(dev);
 	genpd_data->data = sci_dev_data;
-- 
2.21.0


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Re: [PATCH v5 0/3] soc: ti: k3: Allow for exclusive and shared device requests

[Lokesh Vutla]

On 29/07/19 5:54 PM, Lokesh Vutla wrote:
> Sysfw provides an option for requesting exclusive access for a
> device using the flags MSG_FLAG_DEVICE_EXCLUSIVE. If this flag is
> not used, the device is meant to be shared across hosts. Once a device
> is requested from a host with this flag set, any request to this
> device from a different host will be nacked by sysfw.
> 
> Current tisci firmware and pm drivers always requests for device with
> exclusive permissions set. But this is not be true for certain devices
> that are expcted to be shared across different host contexts.
> So add support for getting the shared or exclusive permissions from DT
> and request firmware accordingly.

Gentle Ping on this series.

Thanks and regards,
Lokesh

> 
> Changes since v4: https://patchwork.kernel.org/project/linux-arm-kernel/list/?series=148371
> - Split the driver and arch changes into a separate series.
> - Added Reviewed-by from Nishanth M
> - Rebased on top of v5.3-rc2
> 
> Lokesh Vutla (3):
>   firmware: ti_sci: Allow for device shared and exclusive requests
>   dt-bindings: ti_sci_pm_domains: Add support for exclusive and shared
>     access
>   soc: ti: ti_sci_pm_domains: Add support for exclusive and shared
>     access
> 
>  .../bindings/soc/ti/sci-pm-domain.txt         | 11 ++++-
>  MAINTAINERS                                   |  1 +
>  drivers/firmware/ti_sci.c                     | 45 ++++++++++++++++++-
>  drivers/soc/ti/ti_sci_pm_domains.c            | 23 +++++++++-
>  include/dt-bindings/soc/ti,sci_pm_domain.h    |  9 ++++
>  include/linux/soc/ti/ti_sci_protocol.h        |  3 ++
>  6 files changed, 86 insertions(+), 6 deletions(-)
>  create mode 100644 include/dt-bindings/soc/ti,sci_pm_domain.h
> 

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Re: [PATCH v5 0/3] soc: ti: k3: Allow for exclusive and shared device requests

[santosh.shilimkar]

On 8/20/19 2:48 PM, Lokesh Vutla wrote:
> 
> 
> On 29/07/19 5:54 PM, Lokesh Vutla wrote:
>> Sysfw provides an option for requesting exclusive access for a
>> device using the flags MSG_FLAG_DEVICE_EXCLUSIVE. If this flag is
>> not used, the device is meant to be shared across hosts. Once a device
>> is requested from a host with this flag set, any request to this
>> device from a different host will be nacked by sysfw.
>>
>> Current tisci firmware and pm drivers always requests for device with
>> exclusive permissions set. But this is not be true for certain devices
>> that are expcted to be shared across different host contexts.
>> So add support for getting the shared or exclusive permissions from DT
>> and request firmware accordingly.
> 
> Gentle Ping on this series.
> 
I can queue this up.

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Re: [PATCH v5 0/3] soc: ti: k3: Allow for exclusive and shared device requests

[Lokesh Vutla]

On 21/08/19 1:36 PM, santosh.shilimkar@oracle.com wrote:
> On 8/20/19 2:48 PM, Lokesh Vutla wrote:
>>
>>
>> On 29/07/19 5:54 PM, Lokesh Vutla wrote:
>>> Sysfw provides an option for requesting exclusive access for a
>>> device using the flags MSG_FLAG_DEVICE_EXCLUSIVE. If this flag is
>>> not used, the device is meant to be shared across hosts. Once a device
>>> is requested from a host with this flag set, any request to this
>>> device from a different host will be nacked by sysfw.
>>>
>>> Current tisci firmware and pm drivers always requests for device with
>>> exclusive permissions set. But this is not be true for certain devices
>>> that are expcted to be shared across different host contexts.
>>> So add support for getting the shared or exclusive permissions from DT
>>> and request firmware accordingly.
>>
>> Gentle Ping on this series.
>>
> I can queue this up.

Thanks Santosh.

Regards,
Lokesh


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