[v4,5/5] remoteproc: xilinx: add mailbox channels for rpmsg

  This patch makes each r5 core mailbox client and uses
tx and rx channels to send and receive data to/from
remote processor respectively. This is needed for rpmsg
communication to remote processor.

Signed-off-by: Tanmay Shah <tanmay.shah@amd.com>
---

Changes in v4:
  - move zynqmp_r5_setup_mbox from zynqmp_r5_add_rproc_core to
    zynqmp_r5_cluster_init

Changes in v3:
  - fix multi-line comment format
  - do not mixup mailbox information with memory-regions
  - fix redundant dev_warn for split mode
  - setting up mailboxes should return an error code
  - redesign driver to move mailbox setup during driver probe
  - add .kick function only if mailbox setup is success

v2: https://lore.kernel.org/all/20230126213154.1707300-1-tanmay.shah@amd.com/

 drivers/remoteproc/xlnx_r5_remoteproc.c | 227 +++++++++++++++++++++++-
 1 file changed, 225 insertions(+), 2 deletions(-)
  

Hi,

On Tue, Feb 28, 2023 at 01:02:16PM -0800, Tanmay Shah wrote:
> This patch makes each r5 core mailbox client and uses
> tx and rx channels to send and receive data to/from
> remote processor respectively. This is needed for rpmsg
> communication to remote processor.
> 
> Signed-off-by: Tanmay Shah <tanmay.shah@amd.com>
> ---
> 
> Changes in v4:
>   - move zynqmp_r5_setup_mbox from zynqmp_r5_add_rproc_core to
>     zynqmp_r5_cluster_init
> 
> Changes in v3:
>   - fix multi-line comment format
>   - do not mixup mailbox information with memory-regions
>   - fix redundant dev_warn for split mode
>   - setting up mailboxes should return an error code
>   - redesign driver to move mailbox setup during driver probe
>   - add .kick function only if mailbox setup is success
> 
> v2: https://lore.kernel.org/all/20230126213154.1707300-1-tanmay.shah@amd.com/
> 
>  drivers/remoteproc/xlnx_r5_remoteproc.c | 227 +++++++++++++++++++++++-
>  1 file changed, 225 insertions(+), 2 deletions(-)
> 
> diff --git a/drivers/remoteproc/xlnx_r5_remoteproc.c b/drivers/remoteproc/xlnx_r5_remoteproc.c
> index 5dd007622603..78c1638ccef0 100644
> --- a/drivers/remoteproc/xlnx_r5_remoteproc.c
> +++ b/drivers/remoteproc/xlnx_r5_remoteproc.c
> @@ -8,16 +8,23 @@
>  #include <linux/dma-mapping.h>
>  #include <linux/firmware/xlnx-zynqmp.h>
>  #include <linux/kernel.h>
> +#include <linux/mailbox_client.h>
> +#include <linux/mailbox/zynqmp-ipi-message.h>
>  #include <linux/module.h>
>  #include <linux/of_address.h>
>  #include <linux/of_platform.h>
>  #include <linux/of_reserved_mem.h>
>  #include <linux/platform_device.h>
>  #include <linux/remoteproc.h>
> -#include <linux/slab.h>
>  
>  #include "remoteproc_internal.h"
>  
> +/* IPI buffer MAX length */
> +#define IPI_BUF_LEN_MAX	32U
> +
> +/* RX mailbox client buffer max length */
> +#define MBOX_CLIENT_BUF_MAX	(IPI_BUF_LEN_MAX + \
> +				 sizeof(struct zynqmp_ipi_message))
>  /*
>   * settings for RPU cluster mode which
>   * reflects possible values of xlnx,cluster-mode dt-property
> @@ -43,6 +50,27 @@ struct mem_bank_data {
>  	char *bank_name;
>  };
>  
> +/**
> + * struct mbox_info
> + *
> + * @rx_mc_buf: to copy data from mailbox rx channel
> + * @tx_mc_buf: to copy data to mailbox tx channel
> + * @r5_core: this mailbox's corresponding r5_core pointer
> + * @mbox_work: schedule work after receiving data from mailbox
> + * @mbox_cl: mailbox client
> + * @tx_chan: mailbox tx channel
> + * @rx_chan: mailbox rx channel
> + */
> +struct mbox_info {
> +	unsigned char rx_mc_buf[MBOX_CLIENT_BUF_MAX];
> +	unsigned char tx_mc_buf[MBOX_CLIENT_BUF_MAX];
> +	struct zynqmp_r5_core *r5_core;
> +	struct work_struct mbox_work;
> +	struct mbox_client mbox_cl;
> +	struct mbox_chan *tx_chan;
> +	struct mbox_chan *rx_chan;
> +};
> +
>  /*
>   * Hardcoded TCM bank values. This will be removed once TCM bindings are
>   * accepted for system-dt specifications and upstreamed in linux kernel
> @@ -63,6 +91,7 @@ static const struct mem_bank_data zynqmp_tcm_banks[] = {
>   * @tcm_banks: array of each TCM bank data
>   * @rproc: rproc handle
>   * @pm_domain_id: RPU CPU power domain id
> + * @ipi: pointer to mailbox information
>   */
>  struct zynqmp_r5_core {
>  	struct device *dev;
> @@ -71,6 +100,7 @@ struct zynqmp_r5_core {
>  	struct mem_bank_data **tcm_banks;
>  	struct rproc *rproc;
>  	u32 pm_domain_id;
> +	struct mbox_info *ipi;
>  };
>  
>  /**
> @@ -88,6 +118,178 @@ struct zynqmp_r5_cluster {
>  	struct zynqmp_r5_core **r5_cores;
>  };
>  
> +/**
> + * event_notified_idr_cb() - callback for vq_interrupt per notifyid
> + * @id: rproc->notify id
> + * @ptr: pointer to idr private data
> + * @data: data passed to idr_for_each callback
> + *
> + * Pass notification to remoteproc virtio
> + *
> + * Return: 0. having return is to satisfy the idr_for_each() function
> + *          pointer input argument requirement.
> + **/
> +static int event_notified_idr_cb(int id, void *ptr, void *data)
> +{
> +	struct rproc *rproc = data;
> +
> +	if (rproc_vq_interrupt(rproc, id) == IRQ_NONE)
> +		dev_dbg(&rproc->dev, "data not found for vqid=%d\n", id);
> +
> +	return 0;
> +}
> +
> +/**
> + * handle_event_notified() - remoteproc notification work function
> + * @work: pointer to the work structure
> + *
> + * It checks each registered remoteproc notify IDs.
> + */
> +static void handle_event_notified(struct work_struct *work)
> +{
> +	struct mbox_info *ipi;
> +	struct rproc *rproc;
> +
> +	ipi = container_of(work, struct mbox_info, mbox_work);
> +	rproc = ipi->r5_core->rproc;
> +
> +	/*
> +	 * We only use IPI for interrupt. The RPU firmware side may or may
> +	 * not write the notifyid when it trigger IPI.
> +	 * And thus, we scan through all the registered notifyids and
> +	 * find which one is valid to get the message.
> +	 * Even if message from firmware is NULL, we attempt to get vqid
> +	 */
> +	idr_for_each(&rproc->notifyids, event_notified_idr_cb, rproc);
> +}
> +
> +/**
> + * zynqmp_r5_mb_rx_cb() - receive channel mailbox callback
> + * @cl: mailbox client
> + * @msg: message pointer
> + *
> + * Receive data from ipi buffer, ack interrupt and then
> + * it will schedule the R5 notification work.
> + */
> +static void zynqmp_r5_mb_rx_cb(struct mbox_client *cl, void *msg)
> +{
> +	struct zynqmp_ipi_message *ipi_msg, *buf_msg;
> +	struct mbox_info *ipi;
> +	size_t len;
> +
> +	ipi = container_of(cl, struct mbox_info, mbox_cl);
> +
> +	/* copy data from ipi buffer to r5_core */
> +	ipi_msg = (struct zynqmp_ipi_message *)msg;
> +	buf_msg = (struct zynqmp_ipi_message *)ipi->rx_mc_buf;
> +	len = ipi_msg->len;
> +	if (len > IPI_BUF_LEN_MAX) {
> +		dev_warn(cl->dev, "msg size exceeded than %d\n",
> +			 IPI_BUF_LEN_MAX);
> +		len = IPI_BUF_LEN_MAX;
> +	}
> +	buf_msg->len = len;
> +	memcpy(buf_msg->data, ipi_msg->data, len);
> +
> +	/* received and processed interrupt ack */
> +	if (mbox_send_message(ipi->rx_chan, NULL) < 0)
> +		dev_err(cl->dev, "ack failed to mbox rx_chan\n");
> +
> +	schedule_work(&ipi->mbox_work);
> +}
> +
> +/**
> + * zynqmp_r5_setup_mbox() - Setup mailboxes related properties
> + *			    this is used for each individual R5 core
> + *
> + * @cdev: child node device
> + *
> + * Function to setup mailboxes related properties
> + * return : NULL if failed else pointer to mbox_info
> + */
> +static struct mbox_info *zynqmp_r5_setup_mbox(struct device *cdev)
> +{
> +	struct mbox_client *mbox_cl;
> +	struct mbox_info *ipi;
> +
> +	ipi = kzalloc(sizeof(*ipi), GFP_KERNEL);
> +	if (!ipi)
> +		return NULL;
> +
> +	mbox_cl = &ipi->mbox_cl;
> +	mbox_cl->rx_callback = zynqmp_r5_mb_rx_cb;
> +	mbox_cl->tx_block = false;
> +	mbox_cl->knows_txdone = false;
> +	mbox_cl->tx_done = NULL;
> +	mbox_cl->dev = cdev;
> +
> +	/* Request TX and RX channels */
> +	ipi->tx_chan = mbox_request_channel_byname(mbox_cl, "tx");
> +	if (IS_ERR(ipi->tx_chan)) {
> +		ipi->tx_chan = NULL;
> +		kfree(ipi);
> +		dev_warn(cdev, "mbox tx channel request failed\n");
> +		return NULL;
> +	}
> +
> +	ipi->rx_chan = mbox_request_channel_byname(mbox_cl, "rx");
> +	if (IS_ERR(ipi->rx_chan)) {
> +		mbox_free_channel(ipi->tx_chan);
> +		ipi->rx_chan = NULL;
> +		ipi->tx_chan = NULL;
> +		kfree(ipi);
> +		dev_warn(cdev, "mbox rx channel request failed\n");
> +		return NULL;
> +	}
> +
> +	INIT_WORK(&ipi->mbox_work, handle_event_notified);
> +
> +	return ipi;
> +}
> +
> +static void zynqmp_r5_free_mbox(struct mbox_info *ipi)
> +{
> +	if (!ipi)
> +		return;
> +
> +	if (ipi->tx_chan) {
> +		mbox_free_channel(ipi->tx_chan);
> +		ipi->tx_chan = NULL;
> +	}
> +
> +	if (ipi->rx_chan) {
> +		mbox_free_channel(ipi->rx_chan);
> +		ipi->rx_chan = NULL;
> +	}
> +
> +	kfree(ipi);
> +}
> +
> +/*
> + * zynqmp_r5_core_kick() - kick a firmware if mbox is provided
> + * @rproc: r5 core's corresponding rproc structure
> + * @vqid: virtqueue ID
> + */
> +static void zynqmp_r5_rproc_kick(struct rproc *rproc, int vqid)
> +{
> +	struct zynqmp_r5_core *r5_core = rproc->priv;
> +	struct device *dev = r5_core->dev;
> +	struct zynqmp_ipi_message *mb_msg;
> +	struct mbox_info *ipi;
> +	int ret;
> +
> +	ipi = r5_core->ipi;
> +	if (!ipi)
> +		return;
> +
> +	mb_msg = (struct zynqmp_ipi_message *)ipi->tx_mc_buf;
> +	memcpy(mb_msg->data, &vqid, sizeof(vqid));
> +	mb_msg->len = sizeof(vqid);
> +	ret = mbox_send_message(ipi->tx_chan, mb_msg);
> +	if (ret < 0)
> +		dev_warn(dev, "failed to send message\n");
> +}
> +
>  /*
>   * zynqmp_r5_set_mode()
>   *
> @@ -614,7 +816,7 @@ static int zynqmp_r5_rproc_unprepare(struct rproc *rproc)
>  	return 0;
>  }
>  
> -static const struct rproc_ops zynqmp_r5_rproc_ops = {
> +static struct rproc_ops zynqmp_r5_rproc_ops = {
>  	.prepare	= zynqmp_r5_rproc_prepare,
>  	.unprepare	= zynqmp_r5_rproc_unprepare,
>  	.start		= zynqmp_r5_rproc_start,
> @@ -673,6 +875,7 @@ static struct zynqmp_r5_core *zynqmp_r5_add_rproc_core(struct device *cdev)
>  	}
>  
>  	r5_core->rproc = r5_rproc;
> +

Spurious change.

>  	return r5_core;
>  
>  free_rproc:
> @@ -799,6 +1002,7 @@ static int zynqmp_r5_cluster_init(struct zynqmp_r5_cluster *cluster)
>  	struct device_node *child;
>  	enum rpu_tcm_comb tcm_mode;
>  	int core_count, ret, i;
> +	struct mbox_info *ipi;
>  
>  	ret = of_property_read_u32(dev_node, "xlnx,cluster-mode", &cluster_mode);
>  
> @@ -869,6 +1073,18 @@ static int zynqmp_r5_cluster_init(struct zynqmp_r5_cluster *cluster)
>  
>  		child_devs[i] = &child_pdev->dev;
>  
> +		/*
> +		 * If mailbox nodes are disabled using "status" property then
> +		 * setting up mailbox channels will be failed. In that case we
> +		 * don't really need kick() operation. Include .kick() only if
> +		 * mbox channels are acquired successfully.
> +		 */
> +		ipi = zynqmp_r5_setup_mbox(&child_pdev->dev);
> +		if (ipi)
> +			zynqmp_r5_rproc_ops.kick = zynqmp_r5_rproc_kick;
> +		else
> +			zynqmp_r5_rproc_ops.kick = NULL;
> +

Based on the way this patchset has turned out, I don't think it is required to
do this anymore.  After all, .kick() won't be called if the mailboxes aren't
initialized.

Please move the call to zynqmp_r5_setup_mbox() just below in the next hunk.

Thanks,
Mathieu

>  		/* create and add remoteproc instance of type struct rproc */
>  		r5_cores[i] = zynqmp_r5_add_rproc_core(&child_pdev->dev);
>  		if (IS_ERR(r5_cores[i])) {
> @@ -878,6 +1094,11 @@ static int zynqmp_r5_cluster_init(struct zynqmp_r5_cluster *cluster)
>  			goto release_r5_cores;
>  		}
>  
> +		if (ipi) {
> +			r5_cores[i]->ipi = ipi;
> +			ipi->r5_core = r5_cores[i];
> +		}
> +
>  		/*
>  		 * If two child nodes are available in dts in lockstep mode,
>  		 * then ignore second child node.
> @@ -915,6 +1136,7 @@ static int zynqmp_r5_cluster_init(struct zynqmp_r5_cluster *cluster)
>  	while (i >= 0) {
>  		put_device(child_devs[i]);
>  		if (r5_cores[i]) {
> +			zynqmp_r5_free_mbox(r5_cores[i]->ipi);
>  			of_reserved_mem_device_release(r5_cores[i]->dev);
>  			rproc_del(r5_cores[i]->rproc);
>  			rproc_free(r5_cores[i]->rproc);
> @@ -939,6 +1161,7 @@ static void zynqmp_r5_cluster_exit(void *data)
>  
>  	for (i = 0; i < cluster->core_count; i++) {
>  		r5_core = cluster->r5_cores[i];
> +		zynqmp_r5_free_mbox(r5_core->ipi);
>  		of_reserved_mem_device_release(r5_core->dev);
>  		put_device(r5_core->dev);
>  		rproc_del(r5_core->rproc);
> -- 
> 2.25.1
>
  

On 3/2/23 5:10 PM, Mathieu Poirier wrote:
> Hi,
>
> On Tue, Feb 28, 2023 at 01:02:16PM -0800, Tanmay Shah wrote:
>> This patch makes each r5 core mailbox client and uses
>> tx and rx channels to send and receive data to/from
>> remote processor respectively. This is needed for rpmsg
>> communication to remote processor.
>>
>> Signed-off-by: Tanmay Shah <tanmay.shah@amd.com>
>> ---
>>
>> Changes in v4:
>>    - move zynqmp_r5_setup_mbox from zynqmp_r5_add_rproc_core to
>>      zynqmp_r5_cluster_init
>>
>> Changes in v3:
>>    - fix multi-line comment format
>>    - do not mixup mailbox information with memory-regions
>>    - fix redundant dev_warn for split mode
>>    - setting up mailboxes should return an error code
>>    - redesign driver to move mailbox setup during driver probe
>>    - add .kick function only if mailbox setup is success
>>
>> v2: https://lore.kernel.org/all/20230126213154.1707300-1-tanmay.shah@amd.com/
>>
>>   drivers/remoteproc/xlnx_r5_remoteproc.c | 227 +++++++++++++++++++++++-
>>   1 file changed, 225 insertions(+), 2 deletions(-)
>>
>> diff --git a/drivers/remoteproc/xlnx_r5_remoteproc.c b/drivers/remoteproc/xlnx_r5_remoteproc.c
>> index 5dd007622603..78c1638ccef0 100644
>> --- a/drivers/remoteproc/xlnx_r5_remoteproc.c
>> +++ b/drivers/remoteproc/xlnx_r5_remoteproc.c
>> @@ -8,16 +8,23 @@
>>   #include <linux/dma-mapping.h>
>>   #include <linux/firmware/xlnx-zynqmp.h>
>>   #include <linux/kernel.h>
>> +#include <linux/mailbox_client.h>
>> +#include <linux/mailbox/zynqmp-ipi-message.h>
>>   #include <linux/module.h>
>>   #include <linux/of_address.h>
>>   #include <linux/of_platform.h>
>>   #include <linux/of_reserved_mem.h>
>>   #include <linux/platform_device.h>
>>   #include <linux/remoteproc.h>
>> -#include <linux/slab.h>
>>   
>>   #include "remoteproc_internal.h"
>>   
>> +/* IPI buffer MAX length */
>> +#define IPI_BUF_LEN_MAX	32U
>> +
>> +/* RX mailbox client buffer max length */
>> +#define MBOX_CLIENT_BUF_MAX	(IPI_BUF_LEN_MAX + \
>> +				 sizeof(struct zynqmp_ipi_message))
>>   /*
>>    * settings for RPU cluster mode which
>>    * reflects possible values of xlnx,cluster-mode dt-property
>> @@ -43,6 +50,27 @@ struct mem_bank_data {
>>   	char *bank_name;
>>   };
>>   
>> +/**
>> + * struct mbox_info
>> + *
>> + * @rx_mc_buf: to copy data from mailbox rx channel
>> + * @tx_mc_buf: to copy data to mailbox tx channel
>> + * @r5_core: this mailbox's corresponding r5_core pointer
>> + * @mbox_work: schedule work after receiving data from mailbox
>> + * @mbox_cl: mailbox client
>> + * @tx_chan: mailbox tx channel
>> + * @rx_chan: mailbox rx channel
>> + */
>> +struct mbox_info {
>> +	unsigned char rx_mc_buf[MBOX_CLIENT_BUF_MAX];
>> +	unsigned char tx_mc_buf[MBOX_CLIENT_BUF_MAX];
>> +	struct zynqmp_r5_core *r5_core;
>> +	struct work_struct mbox_work;
>> +	struct mbox_client mbox_cl;
>> +	struct mbox_chan *tx_chan;
>> +	struct mbox_chan *rx_chan;
>> +};
>> +
>>   /*
>>    * Hardcoded TCM bank values. This will be removed once TCM bindings are
>>    * accepted for system-dt specifications and upstreamed in linux kernel
>> @@ -63,6 +91,7 @@ static const struct mem_bank_data zynqmp_tcm_banks[] = {
>>    * @tcm_banks: array of each TCM bank data
>>    * @rproc: rproc handle
>>    * @pm_domain_id: RPU CPU power domain id
>> + * @ipi: pointer to mailbox information
>>    */
>>   struct zynqmp_r5_core {
>>   	struct device *dev;
>> @@ -71,6 +100,7 @@ struct zynqmp_r5_core {
>>   	struct mem_bank_data **tcm_banks;
>>   	struct rproc *rproc;
>>   	u32 pm_domain_id;
>> +	struct mbox_info *ipi;
>>   };
>>   
>>   /**
>> @@ -88,6 +118,178 @@ struct zynqmp_r5_cluster {
>>   	struct zynqmp_r5_core **r5_cores;
>>   };
>>   
>> +/**
>> + * event_notified_idr_cb() - callback for vq_interrupt per notifyid
>> + * @id: rproc->notify id
>> + * @ptr: pointer to idr private data
>> + * @data: data passed to idr_for_each callback
>> + *
>> + * Pass notification to remoteproc virtio
>> + *
>> + * Return: 0. having return is to satisfy the idr_for_each() function
>> + *          pointer input argument requirement.
>> + **/
>> +static int event_notified_idr_cb(int id, void *ptr, void *data)
>> +{
>> +	struct rproc *rproc = data;
>> +
>> +	if (rproc_vq_interrupt(rproc, id) == IRQ_NONE)
>> +		dev_dbg(&rproc->dev, "data not found for vqid=%d\n", id);
>> +
>> +	return 0;
>> +}
>> +
>> +/**
>> + * handle_event_notified() - remoteproc notification work function
>> + * @work: pointer to the work structure
>> + *
>> + * It checks each registered remoteproc notify IDs.
>> + */
>> +static void handle_event_notified(struct work_struct *work)
>> +{
>> +	struct mbox_info *ipi;
>> +	struct rproc *rproc;
>> +
>> +	ipi = container_of(work, struct mbox_info, mbox_work);
>> +	rproc = ipi->r5_core->rproc;
>> +
>> +	/*
>> +	 * We only use IPI for interrupt. The RPU firmware side may or may
>> +	 * not write the notifyid when it trigger IPI.
>> +	 * And thus, we scan through all the registered notifyids and
>> +	 * find which one is valid to get the message.
>> +	 * Even if message from firmware is NULL, we attempt to get vqid
>> +	 */
>> +	idr_for_each(&rproc->notifyids, event_notified_idr_cb, rproc);
>> +}
>> +
>> +/**
>> + * zynqmp_r5_mb_rx_cb() - receive channel mailbox callback
>> + * @cl: mailbox client
>> + * @msg: message pointer
>> + *
>> + * Receive data from ipi buffer, ack interrupt and then
>> + * it will schedule the R5 notification work.
>> + */
>> +static void zynqmp_r5_mb_rx_cb(struct mbox_client *cl, void *msg)
>> +{
>> +	struct zynqmp_ipi_message *ipi_msg, *buf_msg;
>> +	struct mbox_info *ipi;
>> +	size_t len;
>> +
>> +	ipi = container_of(cl, struct mbox_info, mbox_cl);
>> +
>> +	/* copy data from ipi buffer to r5_core */
>> +	ipi_msg = (struct zynqmp_ipi_message *)msg;
>> +	buf_msg = (struct zynqmp_ipi_message *)ipi->rx_mc_buf;
>> +	len = ipi_msg->len;
>> +	if (len > IPI_BUF_LEN_MAX) {
>> +		dev_warn(cl->dev, "msg size exceeded than %d\n",
>> +			 IPI_BUF_LEN_MAX);
>> +		len = IPI_BUF_LEN_MAX;
>> +	}
>> +	buf_msg->len = len;
>> +	memcpy(buf_msg->data, ipi_msg->data, len);
>> +
>> +	/* received and processed interrupt ack */
>> +	if (mbox_send_message(ipi->rx_chan, NULL) < 0)
>> +		dev_err(cl->dev, "ack failed to mbox rx_chan\n");
>> +
>> +	schedule_work(&ipi->mbox_work);
>> +}
>> +
>> +/**
>> + * zynqmp_r5_setup_mbox() - Setup mailboxes related properties
>> + *			    this is used for each individual R5 core
>> + *
>> + * @cdev: child node device
>> + *
>> + * Function to setup mailboxes related properties
>> + * return : NULL if failed else pointer to mbox_info
>> + */
>> +static struct mbox_info *zynqmp_r5_setup_mbox(struct device *cdev)
>> +{
>> +	struct mbox_client *mbox_cl;
>> +	struct mbox_info *ipi;
>> +
>> +	ipi = kzalloc(sizeof(*ipi), GFP_KERNEL);
>> +	if (!ipi)
>> +		return NULL;
>> +
>> +	mbox_cl = &ipi->mbox_cl;
>> +	mbox_cl->rx_callback = zynqmp_r5_mb_rx_cb;
>> +	mbox_cl->tx_block = false;
>> +	mbox_cl->knows_txdone = false;
>> +	mbox_cl->tx_done = NULL;
>> +	mbox_cl->dev = cdev;
>> +
>> +	/* Request TX and RX channels */
>> +	ipi->tx_chan = mbox_request_channel_byname(mbox_cl, "tx");
>> +	if (IS_ERR(ipi->tx_chan)) {
>> +		ipi->tx_chan = NULL;
>> +		kfree(ipi);
>> +		dev_warn(cdev, "mbox tx channel request failed\n");
>> +		return NULL;
>> +	}
>> +
>> +	ipi->rx_chan = mbox_request_channel_byname(mbox_cl, "rx");
>> +	if (IS_ERR(ipi->rx_chan)) {
>> +		mbox_free_channel(ipi->tx_chan);
>> +		ipi->rx_chan = NULL;
>> +		ipi->tx_chan = NULL;
>> +		kfree(ipi);
>> +		dev_warn(cdev, "mbox rx channel request failed\n");
>> +		return NULL;
>> +	}
>> +
>> +	INIT_WORK(&ipi->mbox_work, handle_event_notified);
>> +
>> +	return ipi;
>> +}
>> +
>> +static void zynqmp_r5_free_mbox(struct mbox_info *ipi)
>> +{
>> +	if (!ipi)
>> +		return;
>> +
>> +	if (ipi->tx_chan) {
>> +		mbox_free_channel(ipi->tx_chan);
>> +		ipi->tx_chan = NULL;
>> +	}
>> +
>> +	if (ipi->rx_chan) {
>> +		mbox_free_channel(ipi->rx_chan);
>> +		ipi->rx_chan = NULL;
>> +	}
>> +
>> +	kfree(ipi);
>> +}
>> +
>> +/*
>> + * zynqmp_r5_core_kick() - kick a firmware if mbox is provided
>> + * @rproc: r5 core's corresponding rproc structure
>> + * @vqid: virtqueue ID
>> + */
>> +static void zynqmp_r5_rproc_kick(struct rproc *rproc, int vqid)
>> +{
>> +	struct zynqmp_r5_core *r5_core = rproc->priv;
>> +	struct device *dev = r5_core->dev;
>> +	struct zynqmp_ipi_message *mb_msg;
>> +	struct mbox_info *ipi;
>> +	int ret;
>> +
>> +	ipi = r5_core->ipi;
>> +	if (!ipi)
>> +		return;
>> +
>> +	mb_msg = (struct zynqmp_ipi_message *)ipi->tx_mc_buf;
>> +	memcpy(mb_msg->data, &vqid, sizeof(vqid));
>> +	mb_msg->len = sizeof(vqid);
>> +	ret = mbox_send_message(ipi->tx_chan, mb_msg);
>> +	if (ret < 0)
>> +		dev_warn(dev, "failed to send message\n");
>> +}
>> +
>>   /*
>>    * zynqmp_r5_set_mode()
>>    *
>> @@ -614,7 +816,7 @@ static int zynqmp_r5_rproc_unprepare(struct rproc *rproc)
>>   	return 0;
>>   }
>>   
>> -static const struct rproc_ops zynqmp_r5_rproc_ops = {
>> +static struct rproc_ops zynqmp_r5_rproc_ops = {
>>   	.prepare	= zynqmp_r5_rproc_prepare,
>>   	.unprepare	= zynqmp_r5_rproc_unprepare,
>>   	.start		= zynqmp_r5_rproc_start,
>> @@ -673,6 +875,7 @@ static struct zynqmp_r5_core *zynqmp_r5_add_rproc_core(struct device *cdev)
>>   	}
>>   
>>   	r5_core->rproc = r5_rproc;
>> +
> Spurious change.

Ack will remove it.


>>   	return r5_core;
>>   
>>   free_rproc:
>> @@ -799,6 +1002,7 @@ static int zynqmp_r5_cluster_init(struct zynqmp_r5_cluster *cluster)
>>   	struct device_node *child;
>>   	enum rpu_tcm_comb tcm_mode;
>>   	int core_count, ret, i;
>> +	struct mbox_info *ipi;
>>   
>>   	ret = of_property_read_u32(dev_node, "xlnx,cluster-mode", &cluster_mode);
>>   
>> @@ -869,6 +1073,18 @@ static int zynqmp_r5_cluster_init(struct zynqmp_r5_cluster *cluster)
>>   
>>   		child_devs[i] = &child_pdev->dev;
>>   
>> +		/*
>> +		 * If mailbox nodes are disabled using "status" property then
>> +		 * setting up mailbox channels will be failed. In that case we
>> +		 * don't really need kick() operation. Include .kick() only if
>> +		 * mbox channels are acquired successfully.
>> +		 */
>> +		ipi = zynqmp_r5_setup_mbox(&child_pdev->dev);
>> +		if (ipi)
>> +			zynqmp_r5_rproc_ops.kick = zynqmp_r5_rproc_kick;
>> +		else
>> +			zynqmp_r5_rproc_ops.kick = NULL;
>> +
> Based on the way this patchset has turned out, I don't think it is required to
> do this anymore.  After all, .kick() won't be called if the mailboxes aren't
> initialized.
>
> Please move the call to zynqmp_r5_setup_mbox() just below in the next hunk.


I don't understand this.

So, we are still registering kick call back even if mailboxes aren't setup ?

I am okay with that, I will check flow once more.


>
> Thanks,
> Mathieu
>
>>   		/* create and add remoteproc instance of type struct rproc */
>>   		r5_cores[i] = zynqmp_r5_add_rproc_core(&child_pdev->dev);
>>   		if (IS_ERR(r5_cores[i])) {
>> @@ -878,6 +1094,11 @@ static int zynqmp_r5_cluster_init(struct zynqmp_r5_cluster *cluster)
>>   			goto release_r5_cores;
>>   		}
>>   
>> +		if (ipi) {
>> +			r5_cores[i]->ipi = ipi;
>> +			ipi->r5_core = r5_cores[i];
>> +		}
>> +
>>   		/*
>>   		 * If two child nodes are available in dts in lockstep mode,
>>   		 * then ignore second child node.
>> @@ -915,6 +1136,7 @@ static int zynqmp_r5_cluster_init(struct zynqmp_r5_cluster *cluster)
>>   	while (i >= 0) {
>>   		put_device(child_devs[i]);
>>   		if (r5_cores[i]) {
>> +			zynqmp_r5_free_mbox(r5_cores[i]->ipi);
>>   			of_reserved_mem_device_release(r5_cores[i]->dev);
>>   			rproc_del(r5_cores[i]->rproc);
>>   			rproc_free(r5_cores[i]->rproc);
>> @@ -939,6 +1161,7 @@ static void zynqmp_r5_cluster_exit(void *data)
>>   
>>   	for (i = 0; i < cluster->core_count; i++) {
>>   		r5_core = cluster->r5_cores[i];
>> +		zynqmp_r5_free_mbox(r5_core->ipi);
>>   		of_reserved_mem_device_release(r5_core->dev);
>>   		put_device(r5_core->dev);
>>   		rproc_del(r5_core->rproc);
>> -- 
>> 2.25.1
>>
  

On Fri, 3 Mar 2023 at 09:36, Tanmay Shah <tanmay.shah@amd.com> wrote:
>
>
> On 3/2/23 5:10 PM, Mathieu Poirier wrote:
> > Hi,
> >
> > On Tue, Feb 28, 2023 at 01:02:16PM -0800, Tanmay Shah wrote:
> >> This patch makes each r5 core mailbox client and uses
> >> tx and rx channels to send and receive data to/from
> >> remote processor respectively. This is needed for rpmsg
> >> communication to remote processor.
> >>
> >> Signed-off-by: Tanmay Shah <tanmay.shah@amd.com>
> >> ---
> >>
> >> Changes in v4:
> >>    - move zynqmp_r5_setup_mbox from zynqmp_r5_add_rproc_core to
> >>      zynqmp_r5_cluster_init
> >>
> >> Changes in v3:
> >>    - fix multi-line comment format
> >>    - do not mixup mailbox information with memory-regions
> >>    - fix redundant dev_warn for split mode
> >>    - setting up mailboxes should return an error code
> >>    - redesign driver to move mailbox setup during driver probe
> >>    - add .kick function only if mailbox setup is success
> >>
> >> v2: https://lore.kernel.org/all/20230126213154.1707300-1-tanmay.shah@amd.com/
> >>
> >>   drivers/remoteproc/xlnx_r5_remoteproc.c | 227 +++++++++++++++++++++++-
> >>   1 file changed, 225 insertions(+), 2 deletions(-)
> >>
> >> diff --git a/drivers/remoteproc/xlnx_r5_remoteproc.c b/drivers/remoteproc/xlnx_r5_remoteproc.c
> >> index 5dd007622603..78c1638ccef0 100644
> >> --- a/drivers/remoteproc/xlnx_r5_remoteproc.c
> >> +++ b/drivers/remoteproc/xlnx_r5_remoteproc.c
> >> @@ -8,16 +8,23 @@
> >>   #include <linux/dma-mapping.h>
> >>   #include <linux/firmware/xlnx-zynqmp.h>
> >>   #include <linux/kernel.h>
> >> +#include <linux/mailbox_client.h>
> >> +#include <linux/mailbox/zynqmp-ipi-message.h>
> >>   #include <linux/module.h>
> >>   #include <linux/of_address.h>
> >>   #include <linux/of_platform.h>
> >>   #include <linux/of_reserved_mem.h>
> >>   #include <linux/platform_device.h>
> >>   #include <linux/remoteproc.h>
> >> -#include <linux/slab.h>
> >>
> >>   #include "remoteproc_internal.h"
> >>
> >> +/* IPI buffer MAX length */
> >> +#define IPI_BUF_LEN_MAX     32U
> >> +
> >> +/* RX mailbox client buffer max length */
> >> +#define MBOX_CLIENT_BUF_MAX (IPI_BUF_LEN_MAX + \
> >> +                             sizeof(struct zynqmp_ipi_message))
> >>   /*
> >>    * settings for RPU cluster mode which
> >>    * reflects possible values of xlnx,cluster-mode dt-property
> >> @@ -43,6 +50,27 @@ struct mem_bank_data {
> >>      char *bank_name;
> >>   };
> >>
> >> +/**
> >> + * struct mbox_info
> >> + *
> >> + * @rx_mc_buf: to copy data from mailbox rx channel
> >> + * @tx_mc_buf: to copy data to mailbox tx channel
> >> + * @r5_core: this mailbox's corresponding r5_core pointer
> >> + * @mbox_work: schedule work after receiving data from mailbox
> >> + * @mbox_cl: mailbox client
> >> + * @tx_chan: mailbox tx channel
> >> + * @rx_chan: mailbox rx channel
> >> + */
> >> +struct mbox_info {
> >> +    unsigned char rx_mc_buf[MBOX_CLIENT_BUF_MAX];
> >> +    unsigned char tx_mc_buf[MBOX_CLIENT_BUF_MAX];
> >> +    struct zynqmp_r5_core *r5_core;
> >> +    struct work_struct mbox_work;
> >> +    struct mbox_client mbox_cl;
> >> +    struct mbox_chan *tx_chan;
> >> +    struct mbox_chan *rx_chan;
> >> +};
> >> +
> >>   /*
> >>    * Hardcoded TCM bank values. This will be removed once TCM bindings are
> >>    * accepted for system-dt specifications and upstreamed in linux kernel
> >> @@ -63,6 +91,7 @@ static const struct mem_bank_data zynqmp_tcm_banks[] = {
> >>    * @tcm_banks: array of each TCM bank data
> >>    * @rproc: rproc handle
> >>    * @pm_domain_id: RPU CPU power domain id
> >> + * @ipi: pointer to mailbox information
> >>    */
> >>   struct zynqmp_r5_core {
> >>      struct device *dev;
> >> @@ -71,6 +100,7 @@ struct zynqmp_r5_core {
> >>      struct mem_bank_data **tcm_banks;
> >>      struct rproc *rproc;
> >>      u32 pm_domain_id;
> >> +    struct mbox_info *ipi;
> >>   };
> >>
> >>   /**
> >> @@ -88,6 +118,178 @@ struct zynqmp_r5_cluster {
> >>      struct zynqmp_r5_core **r5_cores;
> >>   };
> >>
> >> +/**
> >> + * event_notified_idr_cb() - callback for vq_interrupt per notifyid
> >> + * @id: rproc->notify id
> >> + * @ptr: pointer to idr private data
> >> + * @data: data passed to idr_for_each callback
> >> + *
> >> + * Pass notification to remoteproc virtio
> >> + *
> >> + * Return: 0. having return is to satisfy the idr_for_each() function
> >> + *          pointer input argument requirement.
> >> + **/
> >> +static int event_notified_idr_cb(int id, void *ptr, void *data)
> >> +{
> >> +    struct rproc *rproc = data;
> >> +
> >> +    if (rproc_vq_interrupt(rproc, id) == IRQ_NONE)
> >> +            dev_dbg(&rproc->dev, "data not found for vqid=%d\n", id);
> >> +
> >> +    return 0;
> >> +}
> >> +
> >> +/**
> >> + * handle_event_notified() - remoteproc notification work function
> >> + * @work: pointer to the work structure
> >> + *
> >> + * It checks each registered remoteproc notify IDs.
> >> + */
> >> +static void handle_event_notified(struct work_struct *work)
> >> +{
> >> +    struct mbox_info *ipi;
> >> +    struct rproc *rproc;
> >> +
> >> +    ipi = container_of(work, struct mbox_info, mbox_work);
> >> +    rproc = ipi->r5_core->rproc;
> >> +
> >> +    /*
> >> +     * We only use IPI for interrupt. The RPU firmware side may or may
> >> +     * not write the notifyid when it trigger IPI.
> >> +     * And thus, we scan through all the registered notifyids and
> >> +     * find which one is valid to get the message.
> >> +     * Even if message from firmware is NULL, we attempt to get vqid
> >> +     */
> >> +    idr_for_each(&rproc->notifyids, event_notified_idr_cb, rproc);
> >> +}
> >> +
> >> +/**
> >> + * zynqmp_r5_mb_rx_cb() - receive channel mailbox callback
> >> + * @cl: mailbox client
> >> + * @msg: message pointer
> >> + *
> >> + * Receive data from ipi buffer, ack interrupt and then
> >> + * it will schedule the R5 notification work.
> >> + */
> >> +static void zynqmp_r5_mb_rx_cb(struct mbox_client *cl, void *msg)
> >> +{
> >> +    struct zynqmp_ipi_message *ipi_msg, *buf_msg;
> >> +    struct mbox_info *ipi;
> >> +    size_t len;
> >> +
> >> +    ipi = container_of(cl, struct mbox_info, mbox_cl);
> >> +
> >> +    /* copy data from ipi buffer to r5_core */
> >> +    ipi_msg = (struct zynqmp_ipi_message *)msg;
> >> +    buf_msg = (struct zynqmp_ipi_message *)ipi->rx_mc_buf;
> >> +    len = ipi_msg->len;
> >> +    if (len > IPI_BUF_LEN_MAX) {
> >> +            dev_warn(cl->dev, "msg size exceeded than %d\n",
> >> +                     IPI_BUF_LEN_MAX);
> >> +            len = IPI_BUF_LEN_MAX;
> >> +    }
> >> +    buf_msg->len = len;
> >> +    memcpy(buf_msg->data, ipi_msg->data, len);
> >> +
> >> +    /* received and processed interrupt ack */
> >> +    if (mbox_send_message(ipi->rx_chan, NULL) < 0)
> >> +            dev_err(cl->dev, "ack failed to mbox rx_chan\n");
> >> +
> >> +    schedule_work(&ipi->mbox_work);
> >> +}
> >> +
> >> +/**
> >> + * zynqmp_r5_setup_mbox() - Setup mailboxes related properties
> >> + *                      this is used for each individual R5 core
> >> + *
> >> + * @cdev: child node device
> >> + *
> >> + * Function to setup mailboxes related properties
> >> + * return : NULL if failed else pointer to mbox_info
> >> + */
> >> +static struct mbox_info *zynqmp_r5_setup_mbox(struct device *cdev)
> >> +{
> >> +    struct mbox_client *mbox_cl;
> >> +    struct mbox_info *ipi;
> >> +
> >> +    ipi = kzalloc(sizeof(*ipi), GFP_KERNEL);
> >> +    if (!ipi)
> >> +            return NULL;
> >> +
> >> +    mbox_cl = &ipi->mbox_cl;
> >> +    mbox_cl->rx_callback = zynqmp_r5_mb_rx_cb;
> >> +    mbox_cl->tx_block = false;
> >> +    mbox_cl->knows_txdone = false;
> >> +    mbox_cl->tx_done = NULL;
> >> +    mbox_cl->dev = cdev;
> >> +
> >> +    /* Request TX and RX channels */
> >> +    ipi->tx_chan = mbox_request_channel_byname(mbox_cl, "tx");
> >> +    if (IS_ERR(ipi->tx_chan)) {
> >> +            ipi->tx_chan = NULL;
> >> +            kfree(ipi);
> >> +            dev_warn(cdev, "mbox tx channel request failed\n");
> >> +            return NULL;
> >> +    }
> >> +
> >> +    ipi->rx_chan = mbox_request_channel_byname(mbox_cl, "rx");
> >> +    if (IS_ERR(ipi->rx_chan)) {
> >> +            mbox_free_channel(ipi->tx_chan);
> >> +            ipi->rx_chan = NULL;
> >> +            ipi->tx_chan = NULL;
> >> +            kfree(ipi);
> >> +            dev_warn(cdev, "mbox rx channel request failed\n");
> >> +            return NULL;
> >> +    }
> >> +
> >> +    INIT_WORK(&ipi->mbox_work, handle_event_notified);
> >> +
> >> +    return ipi;
> >> +}
> >> +
> >> +static void zynqmp_r5_free_mbox(struct mbox_info *ipi)
> >> +{
> >> +    if (!ipi)
> >> +            return;
> >> +
> >> +    if (ipi->tx_chan) {
> >> +            mbox_free_channel(ipi->tx_chan);
> >> +            ipi->tx_chan = NULL;
> >> +    }
> >> +
> >> +    if (ipi->rx_chan) {
> >> +            mbox_free_channel(ipi->rx_chan);
> >> +            ipi->rx_chan = NULL;
> >> +    }
> >> +
> >> +    kfree(ipi);
> >> +}
> >> +
> >> +/*
> >> + * zynqmp_r5_core_kick() - kick a firmware if mbox is provided
> >> + * @rproc: r5 core's corresponding rproc structure
> >> + * @vqid: virtqueue ID
> >> + */
> >> +static void zynqmp_r5_rproc_kick(struct rproc *rproc, int vqid)
> >> +{
> >> +    struct zynqmp_r5_core *r5_core = rproc->priv;
> >> +    struct device *dev = r5_core->dev;
> >> +    struct zynqmp_ipi_message *mb_msg;
> >> +    struct mbox_info *ipi;
> >> +    int ret;
> >> +
> >> +    ipi = r5_core->ipi;
> >> +    if (!ipi)
> >> +            return;
> >> +
> >> +    mb_msg = (struct zynqmp_ipi_message *)ipi->tx_mc_buf;
> >> +    memcpy(mb_msg->data, &vqid, sizeof(vqid));
> >> +    mb_msg->len = sizeof(vqid);
> >> +    ret = mbox_send_message(ipi->tx_chan, mb_msg);
> >> +    if (ret < 0)
> >> +            dev_warn(dev, "failed to send message\n");
> >> +}
> >> +
> >>   /*
> >>    * zynqmp_r5_set_mode()
> >>    *
> >> @@ -614,7 +816,7 @@ static int zynqmp_r5_rproc_unprepare(struct rproc *rproc)
> >>      return 0;
> >>   }
> >>
> >> -static const struct rproc_ops zynqmp_r5_rproc_ops = {
> >> +static struct rproc_ops zynqmp_r5_rproc_ops = {
> >>      .prepare        = zynqmp_r5_rproc_prepare,
> >>      .unprepare      = zynqmp_r5_rproc_unprepare,
> >>      .start          = zynqmp_r5_rproc_start,
> >> @@ -673,6 +875,7 @@ static struct zynqmp_r5_core *zynqmp_r5_add_rproc_core(struct device *cdev)
> >>      }
> >>
> >>      r5_core->rproc = r5_rproc;
> >> +
> > Spurious change.
>
> Ack will remove it.
>
>
> >>      return r5_core;
> >>
> >>   free_rproc:
> >> @@ -799,6 +1002,7 @@ static int zynqmp_r5_cluster_init(struct zynqmp_r5_cluster *cluster)
> >>      struct device_node *child;
> >>      enum rpu_tcm_comb tcm_mode;
> >>      int core_count, ret, i;
> >> +    struct mbox_info *ipi;
> >>
> >>      ret = of_property_read_u32(dev_node, "xlnx,cluster-mode", &cluster_mode);
> >>
> >> @@ -869,6 +1073,18 @@ static int zynqmp_r5_cluster_init(struct zynqmp_r5_cluster *cluster)
> >>
> >>              child_devs[i] = &child_pdev->dev;
> >>
> >> +            /*
> >> +             * If mailbox nodes are disabled using "status" property then
> >> +             * setting up mailbox channels will be failed. In that case we
> >> +             * don't really need kick() operation. Include .kick() only if
> >> +             * mbox channels are acquired successfully.
> >> +             */
> >> +            ipi = zynqmp_r5_setup_mbox(&child_pdev->dev);
> >> +            if (ipi)
> >> +                    zynqmp_r5_rproc_ops.kick = zynqmp_r5_rproc_kick;
> >> +            else
> >> +                    zynqmp_r5_rproc_ops.kick = NULL;
> >> +
> > Based on the way this patchset has turned out, I don't think it is required to
> > do this anymore.  After all, .kick() won't be called if the mailboxes aren't
> > initialized.
> >
> > Please move the call to zynqmp_r5_setup_mbox() just below in the next hunk.
>
>
> I don't understand this.
>
> So, we are still registering kick call back even if mailboxes aren't setup ?
>

Correct.  Just add it to struct zynqmp_r5_rproc_ops the same way the
other operations are (and keep the const).

> I am okay with that, I will check flow once more.
>
>
> >
> > Thanks,
> > Mathieu
> >
> >>              /* create and add remoteproc instance of type struct rproc */
> >>              r5_cores[i] = zynqmp_r5_add_rproc_core(&child_pdev->dev);
> >>              if (IS_ERR(r5_cores[i])) {
> >> @@ -878,6 +1094,11 @@ static int zynqmp_r5_cluster_init(struct zynqmp_r5_cluster *cluster)
> >>                      goto release_r5_cores;
> >>              }
> >>
> >> +            if (ipi) {
> >> +                    r5_cores[i]->ipi = ipi;
> >> +                    ipi->r5_core = r5_cores[i];
> >> +            }
> >> +
> >>              /*
> >>               * If two child nodes are available in dts in lockstep mode,
> >>               * then ignore second child node.
> >> @@ -915,6 +1136,7 @@ static int zynqmp_r5_cluster_init(struct zynqmp_r5_cluster *cluster)
> >>      while (i >= 0) {
> >>              put_device(child_devs[i]);
> >>              if (r5_cores[i]) {
> >> +                    zynqmp_r5_free_mbox(r5_cores[i]->ipi);
> >>                      of_reserved_mem_device_release(r5_cores[i]->dev);
> >>                      rproc_del(r5_cores[i]->rproc);
> >>                      rproc_free(r5_cores[i]->rproc);
> >> @@ -939,6 +1161,7 @@ static void zynqmp_r5_cluster_exit(void *data)
> >>
> >>      for (i = 0; i < cluster->core_count; i++) {
> >>              r5_core = cluster->r5_cores[i];
> >> +            zynqmp_r5_free_mbox(r5_core->ipi);
> >>              of_reserved_mem_device_release(r5_core->dev);
> >>              put_device(r5_core->dev);
> >>              rproc_del(r5_core->rproc);
> >> --
> >> 2.25.1
> >>