linux-kernel - Re: [PATCH 1/2] crypto: af_alg - use DIV_ROUND

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Date:   Tue, 25 May 2021 10:37:44 +0200
From:   Christophe Leroy <christophe.leroy@...roup.eu>
To:     Wu Bo <wubo40@...wei.com>
Cc:     linfeilong@...wei.com, linux-kernel@...r.kernel.org,
        linux-crypto@...r.kernel.org, linux-fsdevel@...r.kernel.org,
        davem@...emloft.net, herbert@...dor.apana.org.au,
        viro@...iv.linux.org.uk
Subject: Re: [PATCH 1/2] crypto: af_alg - use DIV_ROUND_UP helper macro for
 calculations

Wu Bo <wubo40@...wei.com> a écrit :

> From: Wu Bo <wubo40@...wei.com>
>
> Replace open coded divisor calculations with the DIV_ROUND_UP kernel
> macro for better readability.
>
> Signed-off-by: Wu Bo <wubo40@...wei.com>
> ---
>  crypto/af_alg.c | 2 +-
>  1 file changed, 1 insertion(+), 1 deletion(-)
>
> diff --git a/crypto/af_alg.c b/crypto/af_alg.c
> index 18cc82d..8bd288d 100644
> --- a/crypto/af_alg.c
> +++ b/crypto/af_alg.c
> @@ -411,7 +411,7 @@ int af_alg_make_sg(struct af_alg_sgl *sgl,  
> struct iov_iter *iter, int len)
>  	if (n < 0)
>  		return n;
>
> -	npages = (off + n + PAGE_SIZE - 1) >> PAGE_SHIFT;
> +	npages = DIV_ROUND_UP(off + n, PAGE_SIZE);

You should use PFN_UP()

>  	if (WARN_ON(npages == 0))
>  		return -EINVAL;
>  	/* Add one extra for linking */
> --
> 1.8.3.1