[PATCH v4 0/2] remoteproc: stm32: add support of detaching a remote processor

[PATCH v4 0/2] remoteproc: stm32: add support of detaching a remote processor

[Arnaud Pouliquen]

Update from V3:
add Reviewed by Rob Herring in patch 1/2 for bindings

This patchset is the stm32mp1 platform implementation of the detach operation
added in series [1].

On detach, the stm32 rproc driver sends a mailbox signal to the remote 
processor to inform it that it will be detached. 

Applied and tested on Bjorn's "for_next" branch (2b81aa17008e)

[1] https://patchwork.kernel.org/project/linux-remoteproc/list/?series=447171

Arnaud Pouliquen (2):
  dt-bindings: remoteproc: stm32-rproc: add new mailbox channel for
    detach
  remoteproc: stm32: add capability to detach

 .../bindings/remoteproc/st,stm32-rproc.yaml   | 11 +++++-
 drivers/remoteproc/stm32_rproc.c              | 39 ++++++++++++++++++-
 2 files changed, 46 insertions(+), 4 deletions(-)

-- 
2.17.1

[PATCH v4 1/2] dt-bindings: remoteproc: stm32-rproc: add new mailbox channel for detach

[Arnaud Pouliquen]

Add the "detach" mailbox item, that allows to define a mailbox to
send a IPCC signal to the remote processor on remoteproc detach action.

Signed-off-by: Arnaud Pouliquen <arnaud.pouliquen@foss.st.com>
Reviewed-by: Rob Herring <robh@kernel.org>
---
 .../bindings/remoteproc/st,stm32-rproc.yaml           | 11 +++++++++--
 1 file changed, 9 insertions(+), 2 deletions(-)

diff --git a/Documentation/devicetree/bindings/remoteproc/st,stm32-rproc.yaml b/Documentation/devicetree/bindings/remoteproc/st,stm32-rproc.yaml
index a1171dfba024..64afdcfb613d 100644
--- a/Documentation/devicetree/bindings/remoteproc/st,stm32-rproc.yaml
+++ b/Documentation/devicetree/bindings/remoteproc/st,stm32-rproc.yaml
@@ -65,16 +65,23 @@ properties:
           Unidirectional channel:
             - from local to remote, where ACK from the remote means that it is
               ready for shutdown
+      - description: |
+          A channel (d) used by the local proc to notify the remote proc that it
+          has to stop interprocessor communnication.
+          Unidirectional channel:
+            - from local to remote, where ACK from the remote means that communnication
+              as been stopped on the remote side.
     minItems: 1
-    maxItems: 3
+    maxItems: 4
 
   mbox-names:
     items:
       - const: vq0
       - const: vq1
       - const: shutdown
+      - const: detach
     minItems: 1
-    maxItems: 3
+    maxItems: 4
 
   memory-region:
     description:
-- 
2.17.1

[PATCH v4 2/2] remoteproc: stm32: add capability to detach

[Arnaud Pouliquen]

A mechanism similar to the shutdown mailbox signal is implemented to
detach a remote processor.

Upon detachment, a signal is sent to the remote firmware, allowing it
to perform specific actions such as stopping rpmsg communication.

The Cortex-M hold boot is also disabled to allow the remote processor
to restart in case of crash.

Signed-off-by: Arnaud Pouliquen <arnaud.pouliquen@foss.st.com>
Reviewed-by: Mathieu Poirier <mathieu.poirier@linaro.org>
Tested-by: Mathieu Poirier <mathieu.poirier@linaro.org>
---
 drivers/remoteproc/stm32_rproc.c | 39 ++++++++++++++++++++++++++++++--
 1 file changed, 37 insertions(+), 2 deletions(-)

diff --git a/drivers/remoteproc/stm32_rproc.c b/drivers/remoteproc/stm32_rproc.c
index 3d45f51de4d0..7353f9e7e7af 100644
--- a/drivers/remoteproc/stm32_rproc.c
+++ b/drivers/remoteproc/stm32_rproc.c
@@ -28,7 +28,7 @@
 #define RELEASE_BOOT		1
 
 #define MBOX_NB_VQ		2
-#define MBOX_NB_MBX		3
+#define MBOX_NB_MBX		4
 
 #define STM32_SMC_RCC		0x82001000
 #define STM32_SMC_REG_WRITE	0x1
@@ -38,6 +38,7 @@
 #define STM32_MBX_VQ1		"vq1"
 #define STM32_MBX_VQ1_ID	1
 #define STM32_MBX_SHUTDOWN	"shutdown"
+#define STM32_MBX_DETACH	"detach"
 
 #define RSC_TBL_SIZE		1024
 
@@ -336,6 +337,15 @@ static const struct stm32_mbox stm32_rproc_mbox[MBOX_NB_MBX] = {
 			.tx_done = NULL,
 			.tx_tout = 500, /* 500 ms time out */
 		},
+	},
+	{
+		.name = STM32_MBX_DETACH,
+		.vq_id = -1,
+		.client = {
+			.tx_block = true,
+			.tx_done = NULL,
+			.tx_tout = 200, /* 200 ms time out to detach should be fair enough */
+		},
 	}
 };
 
@@ -461,6 +471,25 @@ static int stm32_rproc_attach(struct rproc *rproc)
 	return stm32_rproc_set_hold_boot(rproc, true);
 }
 
+static int stm32_rproc_detach(struct rproc *rproc)
+{
+	struct stm32_rproc *ddata = rproc->priv;
+	int err, dummy_data, idx;
+
+	/* Inform the remote processor of the detach */
+	idx = stm32_rproc_mbox_idx(rproc, STM32_MBX_DETACH);
+	if (idx >= 0 && ddata->mb[idx].chan) {
+		/* A dummy data is sent to allow to block on transmit */
+		err = mbox_send_message(ddata->mb[idx].chan,
+					&dummy_data);
+		if (err < 0)
+			dev_warn(&rproc->dev, "warning: remote FW detach without ack\n");
+	}
+
+	/* Allow remote processor to auto-reboot */
+	return stm32_rproc_set_hold_boot(rproc, false);
+}
+
 static int stm32_rproc_stop(struct rproc *rproc)
 {
 	struct stm32_rproc *ddata = rproc->priv;
@@ -597,7 +626,12 @@ stm32_rproc_get_loaded_rsc_table(struct rproc *rproc, size_t *table_sz)
 	}
 
 done:
-	/* Assuming the resource table fits in 1kB is fair */
+	/*
+	 * Assuming the resource table fits in 1kB is fair.
+	 * Notice for the detach, that this 1 kB memory area has to be reserved in the coprocessor
+	 * firmware for the resource table. On detach, the remoteproc core re-initializes this
+	 * entire area by overwriting it with the initial values stored in rproc->clean_table.
+	 */
 	*table_sz = RSC_TBL_SIZE;
 	return (struct resource_table *)ddata->rsc_va;
 }
@@ -607,6 +641,7 @@ static const struct rproc_ops st_rproc_ops = {
 	.start		= stm32_rproc_start,
 	.stop		= stm32_rproc_stop,
 	.attach		= stm32_rproc_attach,
+	.detach		= stm32_rproc_detach,
 	.kick		= stm32_rproc_kick,
 	.load		= rproc_elf_load_segments,
 	.parse_fw	= stm32_rproc_parse_fw,
-- 
2.17.1

Re: [PATCH v4 2/2] remoteproc: stm32: add capability to detach

[Bjorn Andersson]

On Wed 31 Mar 02:33 CDT 2021, Arnaud Pouliquen wrote:

> A mechanism similar to the shutdown mailbox signal is implemented to
> detach a remote processor.
> 
> Upon detachment, a signal is sent to the remote firmware, allowing it
> to perform specific actions such as stopping rpmsg communication.
> 
> The Cortex-M hold boot is also disabled to allow the remote processor
> to restart in case of crash.
> 
> Signed-off-by: Arnaud Pouliquen <arnaud.pouliquen@foss.st.com>
> Reviewed-by: Mathieu Poirier <mathieu.poirier@linaro.org>
> Tested-by: Mathieu Poirier <mathieu.poirier@linaro.org>
> ---
>  drivers/remoteproc/stm32_rproc.c | 39 ++++++++++++++++++++++++++++++--
>  1 file changed, 37 insertions(+), 2 deletions(-)
> 
> diff --git a/drivers/remoteproc/stm32_rproc.c b/drivers/remoteproc/stm32_rproc.c
> index 3d45f51de4d0..7353f9e7e7af 100644
> --- a/drivers/remoteproc/stm32_rproc.c
> +++ b/drivers/remoteproc/stm32_rproc.c
> @@ -28,7 +28,7 @@
>  #define RELEASE_BOOT		1
>  
>  #define MBOX_NB_VQ		2
> -#define MBOX_NB_MBX		3
> +#define MBOX_NB_MBX		4
>  
>  #define STM32_SMC_RCC		0x82001000
>  #define STM32_SMC_REG_WRITE	0x1
> @@ -38,6 +38,7 @@
>  #define STM32_MBX_VQ1		"vq1"
>  #define STM32_MBX_VQ1_ID	1
>  #define STM32_MBX_SHUTDOWN	"shutdown"
> +#define STM32_MBX_DETACH	"detach"
>  
>  #define RSC_TBL_SIZE		1024
>  
> @@ -336,6 +337,15 @@ static const struct stm32_mbox stm32_rproc_mbox[MBOX_NB_MBX] = {
>  			.tx_done = NULL,
>  			.tx_tout = 500, /* 500 ms time out */
>  		},
> +	},
> +	{
> +		.name = STM32_MBX_DETACH,
> +		.vq_id = -1,
> +		.client = {
> +			.tx_block = true,
> +			.tx_done = NULL,
> +			.tx_tout = 200, /* 200 ms time out to detach should be fair enough */
> +		},
>  	}
>  };
>  
> @@ -461,6 +471,25 @@ static int stm32_rproc_attach(struct rproc *rproc)
>  	return stm32_rproc_set_hold_boot(rproc, true);
>  }
>  
> +static int stm32_rproc_detach(struct rproc *rproc)
> +{
> +	struct stm32_rproc *ddata = rproc->priv;
> +	int err, dummy_data, idx;
> +
> +	/* Inform the remote processor of the detach */
> +	idx = stm32_rproc_mbox_idx(rproc, STM32_MBX_DETACH);
> +	if (idx >= 0 && ddata->mb[idx].chan) {
> +		/* A dummy data is sent to allow to block on transmit */
> +		err = mbox_send_message(ddata->mb[idx].chan,
> +					&dummy_data);

Seems I posted my comment on v1, rather than this latest version. Please
let me know if we should do anything about this dummy_data.

Regards,
Bjorn

> +		if (err < 0)
> +			dev_warn(&rproc->dev, "warning: remote FW detach without ack\n");
> +	}
> +
> +	/* Allow remote processor to auto-reboot */
> +	return stm32_rproc_set_hold_boot(rproc, false);
> +}
> +
>  static int stm32_rproc_stop(struct rproc *rproc)
>  {
>  	struct stm32_rproc *ddata = rproc->priv;
> @@ -597,7 +626,12 @@ stm32_rproc_get_loaded_rsc_table(struct rproc *rproc, size_t *table_sz)
>  	}
>  
>  done:
> -	/* Assuming the resource table fits in 1kB is fair */
> +	/*
> +	 * Assuming the resource table fits in 1kB is fair.
> +	 * Notice for the detach, that this 1 kB memory area has to be reserved in the coprocessor
> +	 * firmware for the resource table. On detach, the remoteproc core re-initializes this
> +	 * entire area by overwriting it with the initial values stored in rproc->clean_table.
> +	 */
>  	*table_sz = RSC_TBL_SIZE;
>  	return (struct resource_table *)ddata->rsc_va;
>  }
> @@ -607,6 +641,7 @@ static const struct rproc_ops st_rproc_ops = {
>  	.start		= stm32_rproc_start,
>  	.stop		= stm32_rproc_stop,
>  	.attach		= stm32_rproc_attach,
> +	.detach		= stm32_rproc_detach,
>  	.kick		= stm32_rproc_kick,
>  	.load		= rproc_elf_load_segments,
>  	.parse_fw	= stm32_rproc_parse_fw,
> -- 
> 2.17.1
> 

Re: [PATCH v4 2/2] remoteproc: stm32: add capability to detach

[Arnaud POULIQUEN]

Hello Bjorn

On 4/13/21 11:34 PM, Bjorn Andersson wrote:
> On Wed 31 Mar 02:33 CDT 2021, Arnaud Pouliquen wrote:
> 
>> A mechanism similar to the shutdown mailbox signal is implemented to
>> detach a remote processor.
>>
>> Upon detachment, a signal is sent to the remote firmware, allowing it
>> to perform specific actions such as stopping rpmsg communication.
>>
>> The Cortex-M hold boot is also disabled to allow the remote processor
>> to restart in case of crash.
>>
>> Signed-off-by: Arnaud Pouliquen <arnaud.pouliquen@foss.st.com>
>> Reviewed-by: Mathieu Poirier <mathieu.poirier@linaro.org>
>> Tested-by: Mathieu Poirier <mathieu.poirier@linaro.org>
>> ---
>>  drivers/remoteproc/stm32_rproc.c | 39 ++++++++++++++++++++++++++++++--
>>  1 file changed, 37 insertions(+), 2 deletions(-)
>>
>> diff --git a/drivers/remoteproc/stm32_rproc.c b/drivers/remoteproc/stm32_rproc.c
>> index 3d45f51de4d0..7353f9e7e7af 100644
>> --- a/drivers/remoteproc/stm32_rproc.c
>> +++ b/drivers/remoteproc/stm32_rproc.c
>> @@ -28,7 +28,7 @@
>>  #define RELEASE_BOOT		1
>>  
>>  #define MBOX_NB_VQ		2
>> -#define MBOX_NB_MBX		3
>> +#define MBOX_NB_MBX		4
>>  
>>  #define STM32_SMC_RCC		0x82001000
>>  #define STM32_SMC_REG_WRITE	0x1
>> @@ -38,6 +38,7 @@
>>  #define STM32_MBX_VQ1		"vq1"
>>  #define STM32_MBX_VQ1_ID	1
>>  #define STM32_MBX_SHUTDOWN	"shutdown"
>> +#define STM32_MBX_DETACH	"detach"
>>  
>>  #define RSC_TBL_SIZE		1024
>>  
>> @@ -336,6 +337,15 @@ static const struct stm32_mbox stm32_rproc_mbox[MBOX_NB_MBX] = {
>>  			.tx_done = NULL,
>>  			.tx_tout = 500, /* 500 ms time out */
>>  		},
>> +	},
>> +	{
>> +		.name = STM32_MBX_DETACH,
>> +		.vq_id = -1,
>> +		.client = {
>> +			.tx_block = true,
>> +			.tx_done = NULL,
>> +			.tx_tout = 200, /* 200 ms time out to detach should be fair enough */
>> +		},
>>  	}
>>  };
>>  
>> @@ -461,6 +471,25 @@ static int stm32_rproc_attach(struct rproc *rproc)
>>  	return stm32_rproc_set_hold_boot(rproc, true);
>>  }
>>  
>> +static int stm32_rproc_detach(struct rproc *rproc)
>> +{
>> +	struct stm32_rproc *ddata = rproc->priv;
>> +	int err, dummy_data, idx;
>> +
>> +	/* Inform the remote processor of the detach */
>> +	idx = stm32_rproc_mbox_idx(rproc, STM32_MBX_DETACH);
>> +	if (idx >= 0 && ddata->mb[idx].chan) {
>> +		/* A dummy data is sent to allow to block on transmit */
>> +		err = mbox_send_message(ddata->mb[idx].chan,
>> +					&dummy_data);
> 
> Seems I posted my comment on v1, rather than this latest version. Please
> let me know if we should do anything about this dummy_data.

Thanks for pointing this out, you are right, the mailbox driver is stm32_ipcc
and it only sends a signal to the remote processor.

As message can be queued by the mailbox framework using a local variable seems
not a good option. As this code is a copy/past of the kick and stop?
I propose to get this one and I will send a new patch to fix the usage in the
whole driver.

Thanks,
Arnaud

> 
> Regards,
> Bjorn
> 
>> +		if (err < 0)
>> +			dev_warn(&rproc->dev, "warning: remote FW detach without ack\n");
>> +	}
>> +
>> +	/* Allow remote processor to auto-reboot */
>> +	return stm32_rproc_set_hold_boot(rproc, false);
>> +}
>> +
>>  static int stm32_rproc_stop(struct rproc *rproc)
>>  {
>>  	struct stm32_rproc *ddata = rproc->priv;
>> @@ -597,7 +626,12 @@ stm32_rproc_get_loaded_rsc_table(struct rproc *rproc, size_t *table_sz)
>>  	}
>>  
>>  done:
>> -	/* Assuming the resource table fits in 1kB is fair */
>> +	/*
>> +	 * Assuming the resource table fits in 1kB is fair.
>> +	 * Notice for the detach, that this 1 kB memory area has to be reserved in the coprocessor
>> +	 * firmware for the resource table. On detach, the remoteproc core re-initializes this
>> +	 * entire area by overwriting it with the initial values stored in rproc->clean_table.
>> +	 */
>>  	*table_sz = RSC_TBL_SIZE;
>>  	return (struct resource_table *)ddata->rsc_va;
>>  }
>> @@ -607,6 +641,7 @@ static const struct rproc_ops st_rproc_ops = {
>>  	.start		= stm32_rproc_start,
>>  	.stop		= stm32_rproc_stop,
>>  	.attach		= stm32_rproc_attach,
>> +	.detach		= stm32_rproc_detach,
>>  	.kick		= stm32_rproc_kick,
>>  	.load		= rproc_elf_load_segments,
>>  	.parse_fw	= stm32_rproc_parse_fw,
>> -- 
>> 2.17.1
>>

Re: [PATCH v4 2/2] remoteproc: stm32: add capability to detach

[Bjorn Andersson]

On Wed 14 Apr 02:23 CDT 2021, Arnaud POULIQUEN wrote:
> On 4/13/21 11:34 PM, Bjorn Andersson wrote:
> > On Wed 31 Mar 02:33 CDT 2021, Arnaud Pouliquen wrote:
[..]
> >> +		err = mbox_send_message(ddata->mb[idx].chan,
> >> +					&dummy_data);
> > 
> > Seems I posted my comment on v1, rather than this latest version. Please
> > let me know if we should do anything about this dummy_data.
> 
> Thanks for pointing this out, you are right, the mailbox driver is stm32_ipcc
> and it only sends a signal to the remote processor.
> 
> As message can be queued by the mailbox framework using a local variable seems
> not a good option. As this code is a copy/past of the kick and stop?
> I propose to get this one and I will send a new patch to fix the usage in the
> whole driver.
> 

That works for me, I've merged the two patches.

Thanks,
Bjorn

Re: [PATCH v4 0/2] remoteproc: stm32: add support of detaching a remote processor

[patchwork-bot+linux-remoteproc]

Hello:

This series was applied to andersson/remoteproc.git (refs/heads/for-next):

On Wed, 31 Mar 2021 09:33:45 +0200 you wrote:
> Update from V3:
> add Reviewed by Rob Herring in patch 1/2 for bindings
> 
> This patchset is the stm32mp1 platform implementation of the detach operation
> added in series [1].
> 
> On detach, the stm32 rproc driver sends a mailbox signal to the remote
> processor to inform it that it will be detached.
> 
> [...]

Here is the summary with links:
  - [v4,1/2] dt-bindings: remoteproc: stm32-rproc: add new mailbox channel for detach
    https://git.kernel.org/andersson/remoteproc/c/aca8f94e5b69
  - [v4,2/2] remoteproc: stm32: add capability to detach
    https://git.kernel.org/andersson/remoteproc/c/edf696f26855

You are awesome, thank you!
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