Re: [PATCH 06/10] ipmi: kcs_bmc: Integrate buffers into driver struct

[Jonathan Cameron]

On Fri,  3 Nov 2023 16:45:18 +1030
Andrew Jeffery <andrew@xxxxxxxxxxxxxxxxxxxx> wrote:

> Consolidate several necessary allocations into one to reduce the number
> of possible error paths.
> 
> Signed-off-by: Andrew Jeffery <andrew@xxxxxxxxxxxxxxxxxxxx>
Gets rid of some of the devm_kfree() fun, so I'm in favor of the change :)

One trivial comment inline.

Reviewed-by: Jonathan Cameron <Jonathan.Cameron@xxxxxxxxxx>

> ---
>  drivers/char/ipmi/kcs_bmc_cdev_ipmi.c | 25 ++++++++-----------------
>  1 file changed, 8 insertions(+), 17 deletions(-)
> 
> diff --git a/drivers/char/ipmi/kcs_bmc_cdev_ipmi.c b/drivers/char/ipmi/kcs_bmc_cdev_ipmi.c
> index 712a80c27060..45ac930172ec 100644
> --- a/drivers/char/ipmi/kcs_bmc_cdev_ipmi.c
> +++ b/drivers/char/ipmi/kcs_bmc_cdev_ipmi.c
> @@ -66,6 +66,10 @@ enum kcs_ipmi_errors {
>  	KCS_UNSPECIFIED_ERROR       = 0xFF
>  };
>  
> +#define DEVICE_NAME "ipmi-kcs"
> +#define KCS_MSG_BUFSIZ    1000
> +#define KCS_ZERO_DATA     0
> +
>  struct kcs_bmc_ipmi {
>  	struct list_head entry;
>  
> @@ -79,24 +83,18 @@ struct kcs_bmc_ipmi {
>  	wait_queue_head_t queue;
>  	bool data_in_avail;
>  	int  data_in_idx;
> -	u8  *data_in;
> +	u8   data_in[KCS_MSG_BUFSIZ];
>  
>  	int  data_out_idx;
>  	int  data_out_len;
> -	u8  *data_out;
> +	u8   data_out[KCS_MSG_BUFSIZ];
>  
>  	struct mutex mutex;
> -	u8 *kbuffer;
> +	u8 kbuffer[KCS_MSG_BUFSIZ];
>  
>  	struct miscdevice miscdev;
>  };
>  
> -#define DEVICE_NAME "ipmi-kcs"
> -
> -#define KCS_MSG_BUFSIZ    1000
> -
> -#define KCS_ZERO_DATA     0
> -
>  /* IPMI 2.0 - Table 9-1, KCS Interface Status Register Bits */
>  #define KCS_STATUS_STATE(state) (state << 6)
>  #define KCS_STATUS_STATE_MASK   GENMASK(7, 6)
> @@ -478,19 +476,15 @@ static int kcs_bmc_ipmi_add_device(struct kcs_bmc_device *kcs_bmc)
>  
>  	spin_lock_init(&priv->lock);
>  	mutex_init(&priv->mutex);
> -
Unrelated change...

>  	init_waitqueue_head(&priv->queue);
>  
>  	priv->client.dev = kcs_bmc;
>  	priv->client.ops = &kcs_bmc_ipmi_client_ops;
> -	priv->data_in = devm_kmalloc(kcs_bmc->dev, KCS_MSG_BUFSIZ, GFP_KERNEL);
> -	priv->data_out = devm_kmalloc(kcs_bmc->dev, KCS_MSG_BUFSIZ, GFP_KERNEL);
> -	priv->kbuffer = devm_kmalloc(kcs_bmc->dev, KCS_MSG_BUFSIZ, GFP_KERNEL);
>  
>  	priv->miscdev.minor = MISC_DYNAMIC_MINOR;
>  	priv->miscdev.name = devm_kasprintf(kcs_bmc->dev, GFP_KERNEL, "%s%u", DEVICE_NAME,
>  					   kcs_bmc->channel);
> -	if (!priv->data_in || !priv->data_out || !priv->kbuffer || !priv->miscdev.name)
> +	if (!priv->miscdev.name)
>  		return -EINVAL;
>  
>  	priv->miscdev.fops = &kcs_bmc_ipmi_fops;
> @@ -529,9 +523,6 @@ static void kcs_bmc_ipmi_remove_device(struct kcs_bmc_device *kcs_bmc)
>  
>  	misc_deregister(&priv->miscdev);
>  	kcs_bmc_disable_device(&priv->client);
> -	devm_kfree(kcs_bmc->dev, priv->kbuffer);
> -	devm_kfree(kcs_bmc->dev, priv->data_out);
> -	devm_kfree(kcs_bmc->dev, priv->data_in);
>  	devm_kfree(kcs_bmc->dev, priv);
>  }
>