linux-kernel - Re: [PATCH v8 3/8] crypto: caam - drop global context pointer and init

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Message-ID: <49971beb-0681-de92-95f5-b18e1be05ce3@nxp.com>
Date:   Tue, 17 Mar 2020 18:45:29 +0200
From:   Horia Geantă <horia.geanta@....com>
To:     Andrey Smirnov <andrew.smirnov@...il.com>,
        "linux-crypto@...r.kernel.org" <linux-crypto@...r.kernel.org>
Cc:     Chris Healy <cphealy@...il.com>,
        Lucas Stach <l.stach@...gutronix.de>,
        Herbert Xu <herbert@...dor.apana.org.au>,
        Iuliana Prodan <iuliana.prodan@....com>,
        "linux-kernel@...r.kernel.org" <linux-kernel@...r.kernel.org>,
        dl-linux-imx <linux-imx@....com>
Subject: Re: [PATCH v8 3/8] crypto: caam - drop global context pointer and
 init_done

On 3/16/2020 5:01 PM, Andrey Smirnov wrote:
> diff --git a/drivers/crypto/caam/caamrng.c b/drivers/crypto/caam/caamrng.c
> index 69a02ac5de54..753625f2b2c0 100644
> --- a/drivers/crypto/caam/caamrng.c
> +++ b/drivers/crypto/caam/caamrng.c
> @@ -70,6 +70,7 @@ struct buf_data {
>  
>  /* rng per-device context */
>  struct caam_rng_ctx {
> +	struct hwrng rng;
>  	struct device *jrdev;
>  	dma_addr_t sh_desc_dma;
>  	u32 sh_desc[DESC_RNG_LEN];
> @@ -78,13 +79,10 @@ struct caam_rng_ctx {
>  	struct buf_data bufs[2];
>  };
[...]
> +static struct caam_rng_ctx *to_caam_rng_ctx(struct hwrng *r)
> +{
> +	return (struct caam_rng_ctx *)r->priv;
> +}
[...]
> -static struct hwrng caam_rng = {
> -	.name		= "rng-caam",
> -	.init           = caam_init,
> -	.cleanup	= caam_cleanup,
> -	.read		= caam_read,
> -};
I would keep this statically allocated, see below.

> @@ -342,18 +332,27 @@ int caam_rng_init(struct device *ctrldev)
>  	if (!rng_inst)
>  		return 0;
>  
> -	rng_ctx = kmalloc(sizeof(*rng_ctx), GFP_DMA | GFP_KERNEL);
> -	if (!rng_ctx)
> +	if (!devres_open_group(ctrldev, caam_rng_init, GFP_KERNEL))
> +		return -ENOMEM;
> +
> +	ctx = devm_kzalloc(ctrldev, sizeof(*ctx), GFP_DMA | GFP_KERNEL);
> +	if (!ctx)
>  		return -ENOMEM;
>  
> +	ctx->rng.name    = "rng-caam";
> +	ctx->rng.init    = caam_init;
> +	ctx->rng.cleanup = caam_cleanup;
> +	ctx->rng.read    = caam_read;
> +	ctx->rng.priv    = (unsigned long)ctx;
> +
>  	dev_info(ctrldev, "registering rng-caam\n");
>  
> -	err = hwrng_register(&caam_rng);
> -	if (!err) {
> -		init_done = true;
> -		return err;
> +	ret = devm_hwrng_register(ctrldev, &ctx->rng);
Now that hwrng.priv is used to keep driver's private data / caam_rng_ctx,
and thus container_of() is no longer needed to get from hwrng struct
to caam_rng_ctx, it's no longer needed to embed struct hwrng
into caam_rng_ctx.

Horia