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 vger.kernel.org (vger.kernel.org [23.128.96.18]) by smtp.lore.kernel.org (Postfix) with ESMTP id 07C54C433F5 for ; Fri, 4 Feb 2022 04:44:53 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1356869AbiBDEov (ORCPT ); Thu, 3 Feb 2022 23:44:51 -0500 Received: from ams.source.kernel.org ([145.40.68.75]:39112 "EHLO ams.source.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S231887AbiBDEou (ORCPT ); Thu, 3 Feb 2022 23:44:50 -0500 Received: from smtp.kernel.org (relay.kernel.org [52.25.139.140]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by ams.source.kernel.org (Postfix) with ESMTPS id 08F2BB8366A for ; Fri, 4 Feb 2022 04:44:49 +0000 (UTC) Received: by smtp.kernel.org (Postfix) with ESMTPSA id B2F14C004E1; Fri, 4 Feb 2022 04:44:44 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=k20201202; t=1643949887; bh=Da4vBP/4mmZmI7+4TG2/E3AHX4y3BvIm0B1N+u0ghYc=; h=Date:From:To:Cc:Subject:References:In-Reply-To:From; b=QNjc1K9RtlOkJ09er7mXypbuACrDB/Yb3dc1HvAxjaXNNFwXrNSuKmG+F87gE2KlJ F95U57FlBPad0SpI1p6GLkiYz9KL/hnm5ClQ9HaCClBygzDUMnBzzOVLRiT7QBS3es aWydb7QcIMKadvgifDZpKws3ZHwbcJJ8Wr4EAiQdQAk5c9i1cKb2UCCh7pGFL+iRvN ui4gsVFXgh9H7BSx+ckSvFHj4UZ20nAaDOIneB7UpmpG/31/h/k9YSFrGODTB5WyOh dkc+WSPJZ3Omm+S8Vb4Rr1ApbiijkhMpDeQE9Lyrv5T4LmOuWebHHxRCOzI4w30T9+ mSPd5GL7IGrOA== Date: Fri, 4 Feb 2022 06:44:38 +0200 From: Mike Rapoport To: Anshuman Khandual Cc: linux-mm@kvack.org, linux-kernel@vger.kernel.org, hch@infradead.org, akpm@linux-foundation.org, Michael Ellerman , Paul Mackerras , linuxppc-dev@lists.ozlabs.org Subject: Re: [RFC V1 04/31] powerpc/mm: Enable ARCH_HAS_VM_GET_PAGE_PROT Message-ID: References: <1643029028-12710-1-git-send-email-anshuman.khandual@arm.com> <1643029028-12710-5-git-send-email-anshuman.khandual@arm.com> <46e15116-78fb-e6fe-e0f0-fe776f9348c3@arm.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <46e15116-78fb-e6fe-e0f0-fe776f9348c3@arm.com> Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Fri, Feb 04, 2022 at 08:27:37AM +0530, Anshuman Khandual wrote: > > On 2/3/22 11:45 PM, Mike Rapoport wrote: > > On Mon, Jan 24, 2022 at 06:26:41PM +0530, Anshuman Khandual wrote: > >> This defines and exports a platform specific custom vm_get_page_prot() via > >> subscribing ARCH_HAS_VM_GET_PAGE_PROT. Subsequently all __SXXX and __PXXX > >> macros can be dropped which are no longer needed. While here, this also > >> localizes arch_vm_get_page_prot() as powerpc_vm_get_page_prot(). > >> > >> Cc: Michael Ellerman > >> Cc: Paul Mackerras > >> Cc: linuxppc-dev@lists.ozlabs.org > >> Cc: linux-kernel@vger.kernel.org > >> Signed-off-by: Anshuman Khandual > >> --- > >> arch/powerpc/Kconfig | 1 + > >> arch/powerpc/include/asm/mman.h | 3 +- > >> arch/powerpc/include/asm/pgtable.h | 19 ------------ > >> arch/powerpc/mm/mmap.c | 47 ++++++++++++++++++++++++++++++ > >> 4 files changed, 49 insertions(+), 21 deletions(-) > >> > >> diff --git a/arch/powerpc/Kconfig b/arch/powerpc/Kconfig > >> index b779603978e1..ddb4a3687c05 100644 > >> --- a/arch/powerpc/Kconfig > >> +++ b/arch/powerpc/Kconfig > >> @@ -135,6 +135,7 @@ config PPC > >> select ARCH_HAS_TICK_BROADCAST if GENERIC_CLOCKEVENTS_BROADCAST > >> select ARCH_HAS_UACCESS_FLUSHCACHE > >> select ARCH_HAS_UBSAN_SANITIZE_ALL > >> + select ARCH_HAS_VM_GET_PAGE_PROT > >> select ARCH_HAVE_NMI_SAFE_CMPXCHG > >> select ARCH_KEEP_MEMBLOCK > >> select ARCH_MIGHT_HAVE_PC_PARPORT > >> diff --git a/arch/powerpc/include/asm/mman.h b/arch/powerpc/include/asm/mman.h > >> index 7cb6d18f5cd6..7b10c2031e82 100644 > >> --- a/arch/powerpc/include/asm/mman.h > >> +++ b/arch/powerpc/include/asm/mman.h > >> @@ -24,7 +24,7 @@ static inline unsigned long arch_calc_vm_prot_bits(unsigned long prot, > >> } > >> #define arch_calc_vm_prot_bits(prot, pkey) arch_calc_vm_prot_bits(prot, pkey) > >> > >> -static inline pgprot_t arch_vm_get_page_prot(unsigned long vm_flags) > >> +static inline pgprot_t powerpc_vm_get_page_prot(unsigned long vm_flags) > >> { > >> #ifdef CONFIG_PPC_MEM_KEYS > >> return (vm_flags & VM_SAO) ? > >> @@ -34,7 +34,6 @@ static inline pgprot_t arch_vm_get_page_prot(unsigned long vm_flags) > >> return (vm_flags & VM_SAO) ? __pgprot(_PAGE_SAO) : __pgprot(0); > >> #endif > >> } > >> -#define arch_vm_get_page_prot(vm_flags) arch_vm_get_page_prot(vm_flags) > >> > >> static inline bool arch_validate_prot(unsigned long prot, unsigned long addr) > >> { > >> diff --git a/arch/powerpc/include/asm/pgtable.h b/arch/powerpc/include/asm/pgtable.h > >> index d564d0ecd4cd..3cbb6de20f9d 100644 > >> --- a/arch/powerpc/include/asm/pgtable.h > >> +++ b/arch/powerpc/include/asm/pgtable.h > >> @@ -20,25 +20,6 @@ struct mm_struct; > >> #include > >> #endif /* !CONFIG_PPC_BOOK3S */ > >> > >> -/* Note due to the way vm flags are laid out, the bits are XWR */ > >> -#define __P000 PAGE_NONE > >> -#define __P001 PAGE_READONLY > >> -#define __P010 PAGE_COPY > >> -#define __P011 PAGE_COPY > >> -#define __P100 PAGE_READONLY_X > >> -#define __P101 PAGE_READONLY_X > >> -#define __P110 PAGE_COPY_X > >> -#define __P111 PAGE_COPY_X > >> - > >> -#define __S000 PAGE_NONE > >> -#define __S001 PAGE_READONLY > >> -#define __S010 PAGE_SHARED > >> -#define __S011 PAGE_SHARED > >> -#define __S100 PAGE_READONLY_X > >> -#define __S101 PAGE_READONLY_X > >> -#define __S110 PAGE_SHARED_X > >> -#define __S111 PAGE_SHARED_X > >> - > >> #ifndef __ASSEMBLY__ > >> > >> #ifndef MAX_PTRS_PER_PGD > >> diff --git a/arch/powerpc/mm/mmap.c b/arch/powerpc/mm/mmap.c > >> index c475cf810aa8..7f05e7903bd2 100644 > >> --- a/arch/powerpc/mm/mmap.c > >> +++ b/arch/powerpc/mm/mmap.c > >> @@ -254,3 +254,50 @@ void arch_pick_mmap_layout(struct mm_struct *mm, struct rlimit *rlim_stack) > >> mm->get_unmapped_area = arch_get_unmapped_area_topdown; > >> } > >> } > >> + > >> +static inline pgprot_t __vm_get_page_prot(unsigned long vm_flags) > >> +{ > >> + switch (vm_flags & (VM_READ | VM_WRITE | VM_EXEC | VM_SHARED)) { > >> + case VM_NONE: > >> + return PAGE_NONE; > >> + case VM_READ: > >> + return PAGE_READONLY; > >> + case VM_WRITE: > >> + return PAGE_COPY; > >> + case VM_READ | VM_WRITE: > >> + return PAGE_COPY; > >> + case VM_EXEC: > >> + return PAGE_READONLY_X; > >> + case VM_EXEC | VM_READ: > >> + return PAGE_READONLY_X; > >> + case VM_EXEC | VM_WRITE: > >> + return PAGE_COPY_X; > >> + case VM_EXEC | VM_READ | VM_WRITE: > >> + return PAGE_COPY_X; > >> + case VM_SHARED: > >> + return PAGE_NONE; > >> + case VM_SHARED | VM_READ: > >> + return PAGE_READONLY; > >> + case VM_SHARED | VM_WRITE: > >> + return PAGE_SHARED; > >> + case VM_SHARED | VM_READ | VM_WRITE: > >> + return PAGE_SHARED; > >> + case VM_SHARED | VM_EXEC: > >> + return PAGE_READONLY_X; > >> + case VM_SHARED | VM_EXEC | VM_READ: > >> + return PAGE_READONLY_X; > >> + case VM_SHARED | VM_EXEC | VM_WRITE: > >> + return PAGE_SHARED_X; > >> + case VM_SHARED | VM_EXEC | VM_READ | VM_WRITE: > >> + return PAGE_SHARED_X; > >> + default: > >> + BUILD_BUG(); > >> + } > >> +} > >> + > >> +pgprot_t vm_get_page_prot(unsigned long vm_flags) > >> +{ > >> + return __pgprot(pgprot_val(__vm_get_page_prot(vm_flags)) | > >> + pgprot_val(powerpc_vm_get_page_prot(vm_flags))); > > Any reason to keep powerpc_vm_get_page_prot() rather than open code it > > here? > > > > This applies to other architectures that implement arch_vm_get_page_prot() > > and/or arch_filter_pgprot() as well. > > Just to minimize the code churn ! But I will be happy to open code them > here (and in other platforms) if that will be preferred. I think this will be clearer because all the processing will be at one place. Besides, this way include/asm/pgtable.h becomes shorter and less crowded. -- Sincerely yours, Mike.