From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from foss.arm.com (foss.arm.com [217.140.110.172]) by smtp.subspace.kernel.org (Postfix) with ESMTP id 2E06AF9D9 for ; Mon, 28 Apr 2025 12:15:23 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=217.140.110.172 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1745842525; cv=none; b=Ew74ImCpnLm6JtbB5kyjG5gIH0moLJ0RXB/TInwmB8VGzfkPNufkUP1XtZ++lv3dOMD3bYShUKhArAyHB+32iX/4UFWqRqUhY0x1amOcTW+768kmYgHxcMxLLED9GGwIaVd/ibFTJmUnvYlx71Mld2NCki53TiPwu5c7Yb7pm7w= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1745842525; c=relaxed/simple; bh=UEFna+Fm2dCI10qgoYtLLtWje8Jeiejw+Hk0uP0V6E0=; h=Message-ID:Date:MIME-Version:Subject:To:Cc:References:From: In-Reply-To:Content-Type; b=dVVadGEB+V+UL5uXpx0lQpZe/gJM2l8B2cKDf8dClUxbsR6eZ/+BssO4OGKl/sqCT3MwNzqOe9eJKd+lM0iAsKmE+DK6JfB+I2+bv3VTjKolESI2P7Rb4r3MQKpDAn53Jq+SocOvL6VMTGqFIBJ6+Nghw9GIsYkmx3eJo+24rzw= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dmarc=pass (p=none dis=none) header.from=arm.com; spf=pass smtp.mailfrom=arm.com; arc=none smtp.client-ip=217.140.110.172 Authentication-Results: smtp.subspace.kernel.org; dmarc=pass (p=none dis=none) header.from=arm.com Authentication-Results: smtp.subspace.kernel.org; spf=pass smtp.mailfrom=arm.com Received: from usa-sjc-imap-foss1.foss.arm.com (unknown [10.121.207.14]) by usa-sjc-mx-foss1.foss.arm.com (Postfix) with ESMTP id B55371516; Mon, 28 Apr 2025 05:15:16 -0700 (PDT) Received: from [10.163.50.165] (unknown [10.163.50.165]) by usa-sjc-imap-foss1.foss.arm.com (Postfix) with ESMTPSA id 67F383F66E; Mon, 28 Apr 2025 05:15:18 -0700 (PDT) Message-ID: Date: Mon, 28 Apr 2025 17:45:13 +0530 Precedence: bulk X-Mailing-List: linux-kernel@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 User-Agent: Mozilla Thunderbird Subject: Re: [PATCH 1/3] mm/io-mapping: precompute remap protection flags for clarity To: Ye Liu , akpm@linux-foundation.org Cc: linux-kernel@vger.kernel.org, linux-mm@kvack.org, rppt@kernel.org, lorenzo.stoakes@oracle.com, Liam.Howlett@oracle.com, david@redhat.com, harry.yoo@oracle.com, riel@surriel.com, vbabka@suse.cz, liuye@kylinos.cn References: <20250427100442.958352-1-ye.liu@linux.dev> <20250427100442.958352-2-ye.liu@linux.dev> Content-Language: en-US From: Anshuman Khandual In-Reply-To: <20250427100442.958352-2-ye.liu@linux.dev> Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 7bit On 4/27/25 15:34, Ye Liu wrote: > From: Ye Liu > > In io_mapping_map_user(), precompute the page protection flags in a local > variable before calling remap_pfn_range_notrack(). > > No functional change. > > Signed-off-by: Ye Liu > --- > mm/io-mapping.c | 7 ++++--- > 1 file changed, 4 insertions(+), 3 deletions(-) > > diff --git a/mm/io-mapping.c b/mm/io-mapping.c > index 01b362799930..f44a6a134712 100644 > --- a/mm/io-mapping.c > +++ b/mm/io-mapping.c > @@ -21,9 +21,10 @@ int io_mapping_map_user(struct io_mapping *iomap, struct vm_area_struct *vma, > if (WARN_ON_ONCE((vma->vm_flags & expected_flags) != expected_flags)) > return -EINVAL; > > + pgprot_t remap_prot = __pgprot((pgprot_val(iomap->prot) & _PAGE_CACHE_MASK) | > + (pgprot_val(vma->vm_page_prot) & ~_PAGE_CACHE_MASK)); > + > /* We rely on prevalidation of the io-mapping to skip track_pfn(). */ > - return remap_pfn_range_notrack(vma, addr, pfn, size, > - __pgprot((pgprot_val(iomap->prot) & _PAGE_CACHE_MASK) | > - (pgprot_val(vma->vm_page_prot) & ~_PAGE_CACHE_MASK))); > + return remap_pfn_range_notrack(vma, addr, pfn, size, remap_prot); > } > EXPORT_SYMBOL_GPL(io_mapping_map_user); Reviewed-by: Anshuman Khandual