From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org Received: from kanga.kvack.org (kanga.kvack.org [205.233.56.17]) by smtp.lore.kernel.org (Postfix) with ESMTP id 185B9C433F5 for ; Thu, 3 Feb 2022 05:24:21 +0000 (UTC) Received: by kanga.kvack.org (Postfix) id 5210F8D0126; Thu, 3 Feb 2022 00:24:21 -0500 (EST) Received: by kanga.kvack.org (Postfix, from userid 40) id 4D0D68D0124; Thu, 3 Feb 2022 00:24:21 -0500 (EST) X-Delivered-To: int-list-linux-mm@kvack.org Received: by kanga.kvack.org (Postfix, from userid 63042) id 3BFA08D0126; Thu, 3 Feb 2022 00:24:21 -0500 (EST) X-Delivered-To: linux-mm@kvack.org Received: from forelay.hostedemail.com (smtprelay0159.hostedemail.com [216.40.44.159]) by kanga.kvack.org (Postfix) with ESMTP id 2FC008D0124 for ; Thu, 3 Feb 2022 00:24:21 -0500 (EST) Received: from smtpin31.hostedemail.com (10.5.19.251.rfc1918.com [10.5.19.251]) by forelay04.hostedemail.com (Postfix) with ESMTP id D62389A80D for ; Thu, 3 Feb 2022 05:24:20 +0000 (UTC) X-FDA: 79100327880.31.806BB71 Received: from foss.arm.com (foss.arm.com [217.140.110.172]) by imf27.hostedemail.com (Postfix) with ESMTP id 3937640002 for ; Thu, 3 Feb 2022 05:24:20 +0000 (UTC) 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 24D841FB; Wed, 2 Feb 2022 21:24:19 -0800 (PST) Received: from [10.163.44.35] (unknown [10.163.44.35]) by usa-sjc-imap-foss1.foss.arm.com (Postfix) with ESMTPSA id CAF003F774; Wed, 2 Feb 2022 21:24:17 -0800 (PST) Subject: Re: [RFC V1 31/31] mm/mmap: Define macros for vm_flags access permission combinations To: linux-mm@kvack.org Cc: linux-kernel@vger.kernel.org, hch@infradead.org, akpm@linux-foundation.org References: <1643029028-12710-1-git-send-email-anshuman.khandual@arm.com> <1643029028-12710-32-git-send-email-anshuman.khandual@arm.com> From: Anshuman Khandual Message-ID: <53026c47-4bfa-44fe-1cba-f9c78d901a02@arm.com> Date: Thu, 3 Feb 2022 10:54:14 +0530 User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:68.0) Gecko/20100101 Thunderbird/68.10.0 MIME-Version: 1.0 In-Reply-To: <1643029028-12710-32-git-send-email-anshuman.khandual@arm.com> Content-Type: text/plain; charset=utf-8 Content-Language: en-US Content-Transfer-Encoding: 7bit X-Rspamd-Server: rspam09 X-Rspamd-Queue-Id: 3937640002 X-Stat-Signature: j8wu88wgizggbswym9wtyiabgrigaxnj X-Rspam-User: nil Authentication-Results: imf27.hostedemail.com; dkim=none; spf=pass (imf27.hostedemail.com: domain of anshuman.khandual@arm.com designates 217.140.110.172 as permitted sender) smtp.mailfrom=anshuman.khandual@arm.com; dmarc=pass (policy=none) header.from=arm.com X-HE-Tag: 1643865860-800643 X-Bogosity: Ham, tests=bogofilter, spamicity=0.000000, version=1.2.4 Sender: owner-linux-mm@kvack.org Precedence: bulk X-Loop: owner-majordomo@kvack.org List-ID: On 1/24/22 6:27 PM, Anshuman Khandual wrote: > These macros will be useful in cleaning up the all those switch statements > in vm_get_page_prot() across all platforms. > > Cc: Andrew Morton > Cc: linux-mm@kvack.org > Cc: linux-kernel@vger.kernel.org > Signed-off-by: Anshuman Khandual > --- > include/linux/mm.h | 39 +++++++++++++++++++++++++++++++++++++++ > 1 file changed, 39 insertions(+) > > diff --git a/include/linux/mm.h b/include/linux/mm.h > index 6c0844b99b3e..b3691eeec500 100644 > --- a/include/linux/mm.h > +++ b/include/linux/mm.h > @@ -2828,6 +2828,45 @@ static inline bool range_in_vma(struct vm_area_struct *vma, > return (vma && vma->vm_start <= start && end <= vma->vm_end); > } > > +/* > + * Access permission related vm_flags combination is used to map into > + * platform defined page protection flags. This enumeration helps in > + * abstracting out possible indices after vm_flags is probed for all > + * access permission i.e (VM_SHARED | VM_EXEC | VM_READ | VM_WRITE). > + * > + * VM_EXEC ---------------------| > + * | > + * VM_WRITE ---------------| | > + * | | > + * VM_READ -----------| | | > + * | | | > + * VM_SHARED ----| | | | > + * | | | | > + * v v v v > + * VMFLAGS_IDX_(S|X)(R|X)(W|X)(E|X) > + * > + * X - Indicates that the access flag is absent > + */ > +enum vmflags_idx { > + VMFLAGS_IDX_XXXX, /* (VM_NONE) */ > + VMFLAGS_IDX_XRXX, /* (VM_READ) */ > + VMFLAGS_IDX_XXWX, /* (VM_WRITE) */ > + VMFLAGS_IDX_XRWX, /* (VM_READ | VM_WRITE) */ > + VMFLAGS_IDX_XXXE, /* (VM_EXEC) */ > + VMFLAGS_IDX_XRXE, /* (VM_EXEC | VM_READ) */ > + VMFLAGS_IDX_XXWE, /* (VM_EXEC | VM_WRITE) */ > + VMFLAGS_IDX_XRWE, /* (VM_EXEC | VM_READ | VM_WRITE) */ > + VMFLAGS_IDX_SXXX, /* (VM_SHARED | VM_NONE) */ > + VMFLAGS_IDX_SRXX, /* (VM_SHARED | VM_READ) */ > + VMFLAGS_IDX_SXWX, /* (VM_SHARED | VM_WRITE) */ > + VMFLAGS_IDX_SRWX, /* (VM_SHARED | VM_READ | VM_WRITE) */ > + VMFLAGS_IDX_SXXE, /* (VM_SHARED | VM_EXEC) */ > + VMFLAGS_IDX_SRXE, /* (VM_SHARED | VM_EXEC | VM_READ) */ > + VMFLAGS_IDX_SXWE, /* (VM_SHARED | VM_EXEC | VM_WRITE) */ > + VMFLAGS_IDX_SRWE, /* (VM_SHARED | VM_EXEC | VM_READ | VM_WRITE) */ > + VMFLAGS_IDX_MAX > +}; Defining platform specific vm_get_page_prot() involves a switch statement with various vm_flags access combinations as cases. Hence I am wondering, will it help to use these above macros, instead of existing combinations separated with '|' flags. I can move this patch earlier in the series and change all platform switch cases. Please do suggest. Thank you. - Anshuman