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Date:   Mon, 26 Jun 2023 13:22:22 -0700
From:   Ira Weiny <ira.weiny@intel.com>
To:     Sumitra Sharma <sumitraartsy@gmail.com>,
        Forest Bond <forest@alittletooquiet.net>,
        Greg Kroah-Hartman <gregkh@linuxfoundation.org>,
        <linux-staging@lists.linux.dev>, <linux-kernel@vger.kernel.org>
CC:     Ira Weiny <ira.weiny@intel.com>, Fabio <fmdefrancesco@gmail.com>,
        "Deepak R Varma" <drv@mailo.com>,
        Sumitra Sharma <sumitraartsy@gmail.com>
Subject: Re: [PATCH] drivers/target: Call page_address() on page acquired
 with GFP_KERNEL flag
Message-ID: <6499f37e43ec9_75179294c3@iweiny-mobl.notmuch>
References: <20230614164454.GA390511@sumitra.com>
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Sumitra Sharma wrote:
> rd_allocate_sgl_table() acquires a page with alloc_pages(GFP_KERNEL, 0).
> Pages allocated with GFP_KERNEL cannot come from Highmem. This is why
> there is no need to call kmap() on them.
> 
> Therefore, use a plain page_address() on that page.
> 
> Signed-off-by: Sumitra Sharma <sumitraartsy@gmail.com>

LGTM:

Reviewed-by: Ira Weiny <ira.weiny@intel.com>

> ---
>  drivers/target/target_core_rd.c | 3 +--
>  1 file changed, 1 insertion(+), 2 deletions(-)
> 
> diff --git a/drivers/target/target_core_rd.c b/drivers/target/target_core_rd.c
> index 6648c1c90e19..d8ea6aff39a2 100644
> --- a/drivers/target/target_core_rd.c
> +++ b/drivers/target/target_core_rd.c
> @@ -159,9 +159,8 @@ static int rd_allocate_sgl_table(struct rd_dev *rd_dev, struct rd_dev_sg_table *
>  			sg_assign_page(&sg[j], pg);
>  			sg[j].length = PAGE_SIZE;
>  
> -			p = kmap(pg);
> +			p = page_address(pg);
>  			memset(p, init_payload, PAGE_SIZE);
> -			kunmap(pg);
>  		}
>  
>  		page_offset += sg_per_table;
> -- 
> 2.25.1
>