[PATCH 0/2] firmware: ti_sci: Add host-id as an optional parameter

[PATCH 0/2] firmware: ti_sci: Add host-id as an optional parameter

[Nishanth Menon]

Hi,

Please find attached series to enable host-id as an optional dt property.

Changes Since RFC:
* Updated commit message based on feedback from Rob.

The series is based on v4.18-rc1 and is available here:
https://github.com/nmenon/linux-2.6-playground/commits/upstream/v4.18-rc1/k3-1-am6-tisci

Consolidated all patches (including all series) are available here:
https://github.com/nmenon/linux-2.6-playground/commits/upstream/v4.18-rc1/k3-am6-integ

Full Boot log (integrated of all series for AM654) is available here:
   https://pastebin.ubuntu.com/p/bBFmnzYtCd/

Nishanth Menon (2):
  Documentation: dt: keystone: ti-sci: Add optional host-id parameter
  firmware: ti_sci: Provide host-id as an optional dt parameter

 .../devicetree/bindings/arm/keystone/ti,sci.txt    |  4 ++++
 drivers/firmware/ti_sci.c                          | 24 ++++++++++++++++++----
 2 files changed, 24 insertions(+), 4 deletions(-)

-- 
2.15.1

[PATCH 1/2] Documentation: dt: keystone: ti-sci: Add optional host-id parameter

[Nishanth Menon]

Texas Instrument's System Control Interface (TISCI) permits
the ability for OSs running in virtual machines to be able to
independently communicate with the firmware without the need going
through an hypervisor.

The "host-id" in effect is the hardware representation of the
host (example: VMs locked to a core) as identified to the System
Controller. Hypervisors can either fill in appropriate host-ids in dt
used for each VM instance OR may use prebuilt blobs where the host-ids
are pre-populated, as appropriate for the OS running in the VMs.

This is introduced as an optional parameter to maintain consistency
with legacy device tree blobs.

We call this with a vendor prefix to prevent any possible confusion
with SCSI ID (m68k) kernel option.

Signed-off-by: Nishanth Menon <nm@ti.com>
---
Changes since RFC:
* Commit message update to elaborate usage in VM

RFC: https://patchwork.kernel.org/patch/10447753/

 Documentation/devicetree/bindings/arm/keystone/ti,sci.txt | 4 ++++
 1 file changed, 4 insertions(+)

diff --git a/Documentation/devicetree/bindings/arm/keystone/ti,sci.txt b/Documentation/devicetree/bindings/arm/keystone/ti,sci.txt
index 31f5f9a104cc..b56a02c10ae6 100644
--- a/Documentation/devicetree/bindings/arm/keystone/ti,sci.txt
+++ b/Documentation/devicetree/bindings/arm/keystone/ti,sci.txt
@@ -45,11 +45,15 @@ Optional Properties:
 	debug_messages - Map the Debug message region
 - reg:  register space corresponding to the debug_messages
 - ti,system-reboot-controller: If system reboot can be triggered by SoC reboot
+- ti,host-id: Integer value corresponding to the host ID assigned by Firmware
+	for identification of host processing entities such as virtual
+	machines
 
 Example (K2G):
 -------------
 	pmmc: pmmc {
 		compatible = "ti,k2g-sci";
+		ti,host-id = <2>;
 		mbox-names = "rx", "tx";
 		mboxes= <&msgmgr &msgmgr_proxy_pmmc_rx>,
 			<&msgmgr &msgmgr_proxy_pmmc_tx>;
-- 
2.15.1

[PATCH 1/2] Documentation: dt: keystone: ti-sci: Add optional host-id parameter

[Rob Herring]

On Tue, Jun 19, 2018 at 02:44:20PM -0500, Nishanth Menon wrote:
> Texas Instrument's System Control Interface (TISCI) permits
> the ability for OSs running in virtual machines to be able to
> independently communicate with the firmware without the need going
> through an hypervisor.
> 
> The "host-id" in effect is the hardware representation of the
> host (example: VMs locked to a core) as identified to the System
> Controller. Hypervisors can either fill in appropriate host-ids in dt
> used for each VM instance OR may use prebuilt blobs where the host-ids
> are pre-populated, as appropriate for the OS running in the VMs.
> 
> This is introduced as an optional parameter to maintain consistency
> with legacy device tree blobs.
> 
> We call this with a vendor prefix to prevent any possible confusion
> with SCSI ID (m68k) kernel option.
> 
> Signed-off-by: Nishanth Menon <nm@ti.com>
> ---
> Changes since RFC:
> * Commit message update to elaborate usage in VM
> 
> RFC: https://patchwork.kernel.org/patch/10447753/
> 
>  Documentation/devicetree/bindings/arm/keystone/ti,sci.txt | 4 ++++
>  1 file changed, 4 insertions(+)

Reviewed-by: Rob Herring <robh@kernel.org>

[PATCH 1/2] Documentation: dt: keystone: ti-sci: Add optional host-id parameter

[Geert Uytterhoeven]

Hi Nishanth,

On Tue, Jun 19, 2018 at 9:45 PM Nishanth Menon <nm@ti.com> wrote:
> Texas Instrument's System Control Interface (TISCI) permits
> the ability for OSs running in virtual machines to be able to
> independently communicate with the firmware without the need going
> through an hypervisor.
>
> The "host-id" in effect is the hardware representation of the
> host (example: VMs locked to a core) as identified to the System
> Controller. Hypervisors can either fill in appropriate host-ids in dt
> used for each VM instance OR may use prebuilt blobs where the host-ids
> are pre-populated, as appropriate for the OS running in the VMs.
>
> This is introduced as an optional parameter to maintain consistency
> with legacy device tree blobs.
>
> We call this with a vendor prefix to prevent any possible confusion
> with SCSI ID (m68k) kernel option.

I'd omit the above paragraph. There's no "host-id" literal involved in the
m68k kernel option, and it is not related to DT at all.

Gr{oetje,eeting}s,

                        Geert

-- 
Geert Uytterhoeven -- There's lots of Linux beyond ia32 -- geert at linux-m68k.org

In personal conversations with technical people, I call myself a hacker. But
when I'm talking to journalists I just say "programmer" or something like that.
                                -- Linus Torvalds

[PATCH 2/2] firmware: ti_sci: Provide host-id as an optional dt parameter

[Nishanth Menon]

Texas Instrument's System Control Interface (TISCI) permits the
ability for Operating Systems to running in virtual machines to be
able to independently communicate with the firmware without the need
going through an hypervisor.

The "host-id" in effect is the hardware representation of the
host (example: VMs locked to a core) as identified to the System
Controller.

Provide support as an optional parameter implementation and use the
compatible data as default if one is not provided by device tree.

Signed-off-by: Nishanth Menon <nm@ti.com>
---
Changes since RFC: None
RFC: https://patchwork.kernel.org/patch/10447715/

 drivers/firmware/ti_sci.c | 24 ++++++++++++++++++++----
 1 file changed, 20 insertions(+), 4 deletions(-)

diff --git a/drivers/firmware/ti_sci.c b/drivers/firmware/ti_sci.c
index 7fa744793bc5..69ed1464175c 100644
--- a/drivers/firmware/ti_sci.c
+++ b/drivers/firmware/ti_sci.c
@@ -66,14 +66,14 @@ struct ti_sci_xfers_info {
 
 /**
  * struct ti_sci_desc - Description of SoC integration
- * @host_id:		Host identifier representing the compute entity
+ * @default_host_id:	Host identifier representing the compute entity
  * @max_rx_timeout_ms:	Timeout for communication with SoC (in Milliseconds)
  * @max_msgs: Maximum number of messages that can be pending
  *		  simultaneously in the system
  * @max_msg_size: Maximum size of data per message that can be handled.
  */
 struct ti_sci_desc {
-	u8 host_id;
+	u8 default_host_id;
 	int max_rx_timeout_ms;
 	int max_msgs;
 	int max_msg_size;
@@ -94,6 +94,7 @@ struct ti_sci_desc {
  * @chan_rx:	Receive mailbox channel
  * @minfo:	Message info
  * @node:	list head
+ * @host_id:	Host ID
  * @users:	Number of users of this instance
  */
 struct ti_sci_info {
@@ -110,6 +111,7 @@ struct ti_sci_info {
 	struct mbox_chan *chan_rx;
 	struct ti_sci_xfers_info minfo;
 	struct list_head node;
+	u8 host_id;
 	/* protected by ti_sci_list_mutex */
 	int users;
 
@@ -370,7 +372,7 @@ static struct ti_sci_xfer *ti_sci_get_one_xfer(struct ti_sci_info *info,
 
 	hdr->seq = xfer_id;
 	hdr->type = msg_type;
-	hdr->host = info->desc->host_id;
+	hdr->host = info->host_id;
 	hdr->flags = msg_flags;
 
 	return xfer;
@@ -1793,7 +1795,7 @@ static int tisci_reboot_handler(struct notifier_block *nb, unsigned long mode,
 
 /* Description for K2G */
 static const struct ti_sci_desc ti_sci_pmmc_k2g_desc = {
-	.host_id = 2,
+	.default_host_id = 2,
 	/* Conservative duration */
 	.max_rx_timeout_ms = 1000,
 	/* Limited by MBOX_TX_QUEUE_LEN. K2G can handle upto 128 messages! */
@@ -1819,6 +1821,7 @@ static int ti_sci_probe(struct platform_device *pdev)
 	int ret = -EINVAL;
 	int i;
 	int reboot = 0;
+	u32 h_id;
 
 	of_id = of_match_device(ti_sci_of_match, dev);
 	if (!of_id) {
@@ -1833,6 +1836,19 @@ static int ti_sci_probe(struct platform_device *pdev)
 
 	info->dev = dev;
 	info->desc = desc;
+	ret = of_property_read_u32(dev->of_node, "ti,host-id", &h_id);
+	/* if the property is not present in DT, use a default from desc */
+	if (ret < 0) {
+		info->host_id = info->desc->default_host_id;
+	} else {
+		if (!h_id) {
+			dev_warn(dev, "Host ID 0 is reserved for firmware\n");
+			info->host_id = info->desc->default_host_id;
+		} else {
+			info->host_id = h_id;
+		}
+	}
+
 	reboot = of_property_read_bool(dev->of_node,
 				       "ti,system-reboot-controller");
 	INIT_LIST_HEAD(&info->node);
-- 
2.15.1