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 58805C433EF for ; Sat, 9 Apr 2022 11:36:29 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S241653AbiDILie (ORCPT ); Sat, 9 Apr 2022 07:38:34 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:35948 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S231778AbiDILi3 (ORCPT ); Sat, 9 Apr 2022 07:38:29 -0400 Received: from pegase2.c-s.fr (pegase2.c-s.fr [93.17.235.10]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 5576E6565; Sat, 9 Apr 2022 04:36:22 -0700 (PDT) Received: from localhost (mailhub3.si.c-s.fr [172.26.127.67]) by localhost (Postfix) with ESMTP id 4KbCkC4fZ6z9sTL; Sat, 9 Apr 2022 13:36:19 +0200 (CEST) X-Virus-Scanned: amavisd-new at c-s.fr Received: from pegase2.c-s.fr ([172.26.127.65]) by localhost (pegase2.c-s.fr [127.0.0.1]) (amavisd-new, port 10024) with ESMTP id lY7tFaIkTcqy; Sat, 9 Apr 2022 13:36:19 +0200 (CEST) Received: from messagerie.si.c-s.fr (messagerie.si.c-s.fr [192.168.25.192]) by pegase2.c-s.fr (Postfix) with ESMTP id 4KbCkC3V0xz9sT3; Sat, 9 Apr 2022 13:36:19 +0200 (CEST) Received: from localhost (localhost [127.0.0.1]) by messagerie.si.c-s.fr (Postfix) with ESMTP id 61A1F8B76D; Sat, 9 Apr 2022 13:36:19 +0200 (CEST) X-Virus-Scanned: amavisd-new at c-s.fr Received: from messagerie.si.c-s.fr ([127.0.0.1]) by localhost (messagerie.si.c-s.fr [127.0.0.1]) (amavisd-new, port 10023) with ESMTP id xy5JHFm3eEDp; Sat, 9 Apr 2022 13:36:19 +0200 (CEST) Received: from [192.168.203.47] (unknown [192.168.203.47]) by messagerie.si.c-s.fr (Postfix) with ESMTP id 88E408B765; Sat, 9 Apr 2022 13:36:18 +0200 (CEST) Message-ID: <8f1d5ba5-c03e-d222-ffc0-d9a6baea1037@csgroup.eu> Date: Sat, 9 Apr 2022 13:36:17 +0200 MIME-Version: 1.0 User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:91.0) Gecko/20100101 Thunderbird/91.7.0 Subject: Re: [PATCH V4 2/7] powerpc/mm: Enable ARCH_HAS_VM_GET_PAGE_PROT Content-Language: fr-FR From: Christophe Leroy To: Anshuman Khandual , linux-mm@kvack.org, akpm@linux-foundation.org Cc: linux-arch@vger.kernel.org, linux-kernel@vger.kernel.org, Christoph Hellwig , Paul Mackerras , sparclinux@vger.kernel.org, linuxppc-dev@lists.ozlabs.org, linux-arm-kernel@lists.infradead.org References: <20220407103251.1209606-1-anshuman.khandual@arm.com> <20220407103251.1209606-3-anshuman.khandual@arm.com> In-Reply-To: Content-Type: text/plain; charset=UTF-8; format=flowed Content-Transfer-Encoding: 8bit Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Le 08/04/2022 à 14:53, Christophe Leroy a écrit : > > > Le 07/04/2022 à 12:32, Anshuman Khandual a écrit : >> This defines and exports a platform specific custom vm_get_page_prot() >> via >> subscribing ARCH_HAS_VM_GET_PAGE_PROT. While here, this also localizes >> arch_vm_get_page_prot() as powerpc_vm_get_page_prot() and moves it near >> 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 | 12 ------------ >>   arch/powerpc/mm/mmap.c          | 26 ++++++++++++++++++++++++++ >>   3 files changed, 27 insertions(+), 12 deletions(-) >> >> diff --git a/arch/powerpc/Kconfig b/arch/powerpc/Kconfig >> index 174edabb74fa..eb9b6ddbf92f 100644 >> --- a/arch/powerpc/Kconfig >> +++ b/arch/powerpc/Kconfig >> @@ -140,6 +140,7 @@ 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..1b024e64c8ec 100644 >> --- a/arch/powerpc/include/asm/mman.h >> +++ b/arch/powerpc/include/asm/mman.h >> @@ -24,18 +24,6 @@ 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) >> -{ >> -#ifdef CONFIG_PPC_MEM_KEYS >> -    return (vm_flags & VM_SAO) ? >> -        __pgprot(_PAGE_SAO | vmflag_to_pte_pkey_bits(vm_flags)) : >> -        __pgprot(0 | vmflag_to_pte_pkey_bits(vm_flags)); >> -#else >> -    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) >>   { >>       if (prot & ~(PROT_READ | PROT_WRITE | PROT_EXEC | PROT_SEM | >> PROT_SAO)) >> diff --git a/arch/powerpc/mm/mmap.c b/arch/powerpc/mm/mmap.c >> index c475cf810aa8..cd17bd6fa36b 100644 >> --- a/arch/powerpc/mm/mmap.c >> +++ b/arch/powerpc/mm/mmap.c >> @@ -254,3 +254,29 @@ void arch_pick_mmap_layout(struct mm_struct *mm, >> struct rlimit *rlim_stack) >>           mm->get_unmapped_area = arch_get_unmapped_area_topdown; >>       } >>   } >> + >> +#ifdef CONFIG_PPC64 >> +static pgprot_t powerpc_vm_get_page_prot(unsigned long vm_flags) >> +{ >> +#ifdef CONFIG_PPC_MEM_KEYS >> +    return (vm_flags & VM_SAO) ? >> +        __pgprot(_PAGE_SAO | vmflag_to_pte_pkey_bits(vm_flags)) : >> +        __pgprot(0 | vmflag_to_pte_pkey_bits(vm_flags)); >> +#else >> +    return (vm_flags & VM_SAO) ? __pgprot(_PAGE_SAO) : __pgprot(0); >> +#endif >> +} >> +#else >> +static pgprot_t powerpc_vm_get_page_prot(unsigned long vm_flags) >> +{ >> +    return __pgprot(0); >> +} >> +#endif /* CONFIG_PPC64 */ > > Can we reduce this forest of #ifdefs and make it more readable ? > > mm/mmap.c is going away with patch > https://patchwork.ozlabs.org/project/linuxppc-dev/patch/d6d849621f821af253e777a24eda4c648814a76e.1646847562.git.christophe.leroy@csgroup.eu/ > > > So it would be better to add two versions of vm_get_page_prot(), for > instance one in mm/pgtable_64.c and one in mm/pgtable_32.c Indeed, you don't need anything at all for PPC32. All you need to do is select ARCH_HAS_VM_GET_PAGE_PROT if PPC64 And in fact it could even be PPC_BOOK3S_64 instead of PPC64 because CONFIG_PPC_MEM_KEYS depends on PPC_BOOK3S_64 and _PAGE_SAO is 0 on nohash/64. So you can then put it into arch/powerpc/mm/book3s64/pgtable.c > > >> + >> +pgprot_t vm_get_page_prot(unsigned long vm_flags) >> +{ >> +    return __pgprot(pgprot_val(protection_map[vm_flags & >> +            (VM_READ|VM_WRITE|VM_EXEC|VM_SHARED)]) | >> +           pgprot_val(powerpc_vm_get_page_prot(vm_flags))); >> +} >> +EXPORT_SYMBOL(vm_get_page_prot); > > By the way I'm a bit puzzled with the name powerpc_vm_get_page_prot(), > the name suggests that it's just a powerpc replacement of > vm_get_page_prot(). I'd prefer if it was named __vm_get_page_prot(), it > would be clearer that it is a complement to vm_get_page_prot() and not a > remplacement. > > Christophe