Message-ID: <21302696-aadc-2005-bb64-ec807e737d1a@quicinc.com>
Date:   Tue, 24 Jan 2023 22:30:42 -0800
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From:   Chris Lew <quic_clew@quicinc.com>
Subject: Re: [PATCH 2/6] rpmsg: glink: smem: Wrap driver context
To:     Bjorn Andersson <quic_bjorande@quicinc.com>,
        Bjorn Andersson <andersson@kernel.org>,
        Mathieu Poirier <mathieu.poirier@linaro.org>
CC:     <linux-arm-msm@vger.kernel.org>,
        <linux-remoteproc@vger.kernel.org>, <linux-kernel@vger.kernel.org>
References: <20230109224001.1706516-1-quic_bjorande@quicinc.com>
 <20230109224001.1706516-3-quic_bjorande@quicinc.com>
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In-Reply-To: <20230109224001.1706516-3-quic_bjorande@quicinc.com>
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On 1/9/2023 2:39 PM, Bjorn Andersson wrote:
> The Glink SMEM driver allocates a struct device and hangs two
> devres-allocated pipe objects thereon. To facilitate the move of
> interrupt and mailbox handling to the driver, introduce a wrapper object
> capturing the device, glink reference and remote processor id.
> 
> The type of the remoteproc reference is updated, as these are
> specifically targetting the SMEM implementation.

s/targetting/targeting

> 
> Signed-off-by: Bjorn Andersson <quic_bjorande@quicinc.com>
> ---
>   drivers/remoteproc/qcom_common.h |  3 +-
>   drivers/rpmsg/qcom_glink_smem.c  | 76 ++++++++++++++++++++------------
>   include/linux/rpmsg/qcom_glink.h | 12 ++---
>   3 files changed, 55 insertions(+), 36 deletions(-)
> 
> diff --git a/drivers/remoteproc/qcom_common.h b/drivers/remoteproc/qcom_common.h
> index c35adf730be0..2747c7d9ba44 100644
> --- a/drivers/remoteproc/qcom_common.h
> +++ b/drivers/remoteproc/qcom_common.h
> @@ -6,6 +6,7 @@
>   #include "remoteproc_internal.h"
>   #include <linux/soc/qcom/qmi.h>
>   
> +struct qcom_glink_smem;
>   struct qcom_sysmon;
>   
>   struct qcom_rproc_glink {
> @@ -15,7 +16,7 @@ struct qcom_rproc_glink {
>   
>   	struct device *dev;
>   	struct device_node *node;
> -	struct qcom_glink *edge;
> +	struct qcom_glink_smem *edge;
>   };
>   
>   struct qcom_rproc_subdev {
> diff --git a/drivers/rpmsg/qcom_glink_smem.c b/drivers/rpmsg/qcom_glink_smem.c
> index 579bc4443f6d..703e63fa5a86 100644
> --- a/drivers/rpmsg/qcom_glink_smem.c
> +++ b/drivers/rpmsg/qcom_glink_smem.c
> @@ -33,6 +33,14 @@
>   #define SMEM_GLINK_NATIVE_XPRT_FIFO_0		479
>   #define SMEM_GLINK_NATIVE_XPRT_FIFO_1		480
>   
> +struct qcom_glink_smem {
> +	struct device dev;
> +
> +	struct qcom_glink *glink;
> +
> +	u32 remote_pid;
> +};
> +
>   struct glink_smem_pipe {
>   	struct qcom_glink_pipe native;
>   
> @@ -41,7 +49,7 @@ struct glink_smem_pipe {
>   
>   	void *fifo;
>   
> -	int remote_pid;
> +	struct qcom_glink_smem *smem;
>   };
>   
>   #define to_smem_pipe(p) container_of(p, struct glink_smem_pipe, native)
> @@ -49,13 +57,14 @@ struct glink_smem_pipe {
>   static size_t glink_smem_rx_avail(struct qcom_glink_pipe *np)
>   {
>   	struct glink_smem_pipe *pipe = to_smem_pipe(np);
> +	struct qcom_glink_smem *smem = pipe->smem;
>   	size_t len;
>   	void *fifo;
>   	u32 head;
>   	u32 tail;
>   
>   	if (!pipe->fifo) {
> -		fifo = qcom_smem_get(pipe->remote_pid,
> +		fifo = qcom_smem_get(smem->remote_pid,
>   				     SMEM_GLINK_NATIVE_XPRT_FIFO_1, &len);
>   		if (IS_ERR(fifo)) {
>   			pr_err("failed to acquire RX fifo handle: %ld\n",
> @@ -179,45 +188,49 @@ static void glink_smem_tx_write(struct qcom_glink_pipe *glink_pipe,
>   
>   static void qcom_glink_smem_release(struct device *dev)
>   {
> -	kfree(dev);
> +	struct qcom_glink_smem *smem = container_of(dev, struct qcom_glink_smem, dev);
> +
> +	kfree(smem);
>   }
>   
> -struct qcom_glink *qcom_glink_smem_register(struct device *parent,
> -					    struct device_node *node)
> +struct qcom_glink_smem *qcom_glink_smem_register(struct device *parent,
> +						 struct device_node *node)
>   {
>   	struct glink_smem_pipe *rx_pipe;
>   	struct glink_smem_pipe *tx_pipe;
>   	struct qcom_glink *glink;
> -	struct device *dev;
> +	struct qcom_glink_smem *smem;

I think we're following reverse christmas tree in this file

>   	u32 remote_pid;
>   	__le32 *descs;
>   	size_t size;
>   	int ret;
>   
> -	dev = kzalloc(sizeof(*dev), GFP_KERNEL);
> -	if (!dev)
> +	smem = kzalloc(sizeof(*smem), GFP_KERNEL);
> +	if (!smem)
>   		return ERR_PTR(-ENOMEM);
>

Would it be proper to keep a pointer to dev and avoid all the changes to 
smem->dev use?

dev = &smem->dev;

> -	dev->parent = parent;
> -	dev->of_node = node;
> -	dev->release = qcom_glink_smem_release;
> -	dev_set_name(dev, "%s:%pOFn", dev_name(parent->parent), node);
> -	ret = device_register(dev);
> +	smem->dev.parent = parent;
> +	smem->dev.of_node = node;
> +	smem->dev.release = qcom_glink_smem_release;
> +	dev_set_name(&smem->dev, "%s:%pOFn", dev_name(parent->parent), node);
> +	ret = device_register(&smem->dev);
>   	if (ret) {
>   		pr_err("failed to register glink edge\n");
> -		put_device(dev);
> +		put_device(&smem->dev);
>   		return ERR_PTR(ret);
>   	}
>   
> -	ret = of_property_read_u32(dev->of_node, "qcom,remote-pid",
> +	ret = of_property_read_u32(smem->dev.of_node, "qcom,remote-pid",
>   				   &remote_pid);
>   	if (ret) {
> -		dev_err(dev, "failed to parse qcom,remote-pid\n");
> +		dev_err(&smem->dev, "failed to parse qcom,remote-pid\n");
>   		goto err_put_dev;
>   	}
>   
> -	rx_pipe = devm_kzalloc(dev, sizeof(*rx_pipe), GFP_KERNEL);
> -	tx_pipe = devm_kzalloc(dev, sizeof(*tx_pipe), GFP_KERNEL);
> +	smem->remote_pid = remote_pid;
> +
> +	rx_pipe = devm_kzalloc(&smem->dev, sizeof(*rx_pipe), GFP_KERNEL);
> +	tx_pipe = devm_kzalloc(&smem->dev, sizeof(*tx_pipe), GFP_KERNEL);
>   	if (!rx_pipe || !tx_pipe) {
>   		ret = -ENOMEM;
>   		goto err_put_dev;
> @@ -226,20 +239,20 @@ struct qcom_glink *qcom_glink_smem_register(struct device *parent,
>   	ret = qcom_smem_alloc(remote_pid,
>   			      SMEM_GLINK_NATIVE_XPRT_DESCRIPTOR, 32);
>   	if (ret && ret != -EEXIST) {
> -		dev_err(dev, "failed to allocate glink descriptors\n");
> +		dev_err(&smem->dev, "failed to allocate glink descriptors\n");
>   		goto err_put_dev;
>   	}
>   
>   	descs = qcom_smem_get(remote_pid,
>   			      SMEM_GLINK_NATIVE_XPRT_DESCRIPTOR, &size);
>   	if (IS_ERR(descs)) {
> -		dev_err(dev, "failed to acquire xprt descriptor\n");
> +		dev_err(&smem->dev, "failed to acquire xprt descriptor\n");
>   		ret = PTR_ERR(descs);
>   		goto err_put_dev;
>   	}
>   
>   	if (size != 32) {
> -		dev_err(dev, "glink descriptor of invalid size\n");
> +		dev_err(&smem->dev, "glink descriptor of invalid size\n");
>   		ret = -EINVAL;
>   		goto err_put_dev;
>   	}
> @@ -252,31 +265,31 @@ struct qcom_glink *qcom_glink_smem_register(struct device *parent,
>   	ret = qcom_smem_alloc(remote_pid, SMEM_GLINK_NATIVE_XPRT_FIFO_0,
>   			      SZ_16K);
>   	if (ret && ret != -EEXIST) {
> -		dev_err(dev, "failed to allocate TX fifo\n");
> +		dev_err(&smem->dev, "failed to allocate TX fifo\n");
>   		goto err_put_dev;
>   	}
>   
>   	tx_pipe->fifo = qcom_smem_get(remote_pid, SMEM_GLINK_NATIVE_XPRT_FIFO_0,
>   				      &tx_pipe->native.length);
>   	if (IS_ERR(tx_pipe->fifo)) {
> -		dev_err(dev, "failed to acquire TX fifo\n");
> +		dev_err(&smem->dev, "failed to acquire TX fifo\n");
>   		ret = PTR_ERR(tx_pipe->fifo);
>   		goto err_put_dev;
>   	}
>   
> +	rx_pipe->smem = smem;
>   	rx_pipe->native.avail = glink_smem_rx_avail;
>   	rx_pipe->native.peak = glink_smem_rx_peak;
>   	rx_pipe->native.advance = glink_smem_rx_advance;
> -	rx_pipe->remote_pid = remote_pid;
>   
> +	tx_pipe->smem = smem;
>   	tx_pipe->native.avail = glink_smem_tx_avail;
>   	tx_pipe->native.write = glink_smem_tx_write;
> -	tx_pipe->remote_pid = remote_pid;
>   
>   	*rx_pipe->tail = 0;
>   	*tx_pipe->head = 0;
>   
> -	glink = qcom_glink_native_probe(dev,
> +	glink = qcom_glink_native_probe(&smem->dev,
>   					GLINK_FEATURE_INTENT_REUSE,
>   					&rx_pipe->native, &tx_pipe->native,
>   					false);
> @@ -285,17 +298,22 @@ struct qcom_glink *qcom_glink_smem_register(struct device *parent,
>   		goto err_put_dev;
>   	}
>   
> -	return glink;
> +	smem->glink = glink;
> +
> +	return smem;
> +
>   
>   err_put_dev:
> -	device_unregister(dev);
> +	device_unregister(&smem->dev);
>   
>   	return ERR_PTR(ret);
>   }
>   EXPORT_SYMBOL_GPL(qcom_glink_smem_register);
>   
> -void qcom_glink_smem_unregister(struct qcom_glink *glink)
> +void qcom_glink_smem_unregister(struct qcom_glink_smem *smem)
>   {
> +	struct qcom_glink *glink = smem->glink;
> +
>   	qcom_glink_native_remove(glink);
>   	qcom_glink_native_unregister(glink);
>   }
> diff --git a/include/linux/rpmsg/qcom_glink.h b/include/linux/rpmsg/qcom_glink.h
> index 22fc3a69b683..bfbd48f435fa 100644
> --- a/include/linux/rpmsg/qcom_glink.h
> +++ b/include/linux/rpmsg/qcom_glink.h
> @@ -5,7 +5,7 @@
>   
>   #include <linux/device.h>
>   
> -struct qcom_glink;
> +struct qcom_glink_smem;
>   
>   #if IS_ENABLED(CONFIG_RPMSG_QCOM_GLINK)
>   void qcom_glink_ssr_notify(const char *ssr_name);
> @@ -15,20 +15,20 @@ static inline void qcom_glink_ssr_notify(const char *ssr_name) {}
>   
>   #if IS_ENABLED(CONFIG_RPMSG_QCOM_GLINK_SMEM)
>   
> -struct qcom_glink *qcom_glink_smem_register(struct device *parent,
> -					    struct device_node *node);
> -void qcom_glink_smem_unregister(struct qcom_glink *glink);
> +struct qcom_glink_smem *qcom_glink_smem_register(struct device *parent,
> +						 struct device_node *node);
> +void qcom_glink_smem_unregister(struct qcom_glink_smem *glink);
>   
>   #else
>   
> -static inline struct qcom_glink *
> +static inline struct qcom_glink_smem *
>   qcom_glink_smem_register(struct device *parent,
>   			 struct device_node *node)
>   {
>   	return NULL;
>   }
>   
> -static inline void qcom_glink_smem_unregister(struct qcom_glink *glink) {}
> +static inline void qcom_glink_smem_unregister(struct qcom_glink_smem *glink) {}
>   #endif
>   
>   #endif