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 E698FC433EF for ; Thu, 27 Jan 2022 04:06:04 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S235944AbiA0EGE (ORCPT ); Wed, 26 Jan 2022 23:06:04 -0500 Received: from foss.arm.com ([217.140.110.172]:33258 "EHLO foss.arm.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S235900AbiA0EGD (ORCPT ); Wed, 26 Jan 2022 23:06:03 -0500 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 B20D11FB; Wed, 26 Jan 2022 20:06:02 -0800 (PST) Received: from [10.163.42.218] (unknown [10.163.42.218]) by usa-sjc-imap-foss1.foss.arm.com (Postfix) with ESMTPSA id 119263F7D8; Wed, 26 Jan 2022 20:05:59 -0800 (PST) Subject: Re: [RFC V1 21/31] parisc/mm: Enable ARCH_HAS_VM_GET_PAGE_PROT To: Rolf Eike Beer , linux-mm@kvack.org Cc: linux-kernel@vger.kernel.org, hch@infradead.org, akpm@linux-foundation.org, "James E.J. Bottomley" , linux-parisc@vger.kernel.org References: <1643029028-12710-1-git-send-email-anshuman.khandual@arm.com> <1643029028-12710-22-git-send-email-anshuman.khandual@arm.com> <11909976.O9o76ZdvQC@eto.sf-tec.de> From: Anshuman Khandual Message-ID: Date: Thu, 27 Jan 2022 09:36:05 +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: <11909976.O9o76ZdvQC@eto.sf-tec.de> Content-Type: text/plain; charset=windows-1252 Content-Language: en-US Content-Transfer-Encoding: 7bit Precedence: bulk List-ID: X-Mailing-List: linux-parisc@vger.kernel.org On 1/25/22 10:23 PM, Rolf Eike Beer wrote: > 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. >> >> Cc: "James E.J. Bottomley" >> Cc: linux-parisc@vger.kernel.org >> Cc: linux-kernel@vger.kernel.org >> Signed-off-by: Anshuman Khandual >> --- >> arch/parisc/Kconfig | 1 + >> arch/parisc/include/asm/pgtable.h | 20 --------------- >> arch/parisc/mm/init.c | 41 +++++++++++++++++++++++++++++++ >> 3 files changed, 42 insertions(+), 20 deletions(-) >> >> diff --git a/arch/parisc/Kconfig b/arch/parisc/Kconfig >> index 43c1c880def6..de512f120b50 100644 >> --- a/arch/parisc/Kconfig >> +++ b/arch/parisc/Kconfig >> @@ -10,6 +10,7 @@ config PARISC >> select ARCH_HAS_ELF_RANDOMIZE >> select ARCH_HAS_STRICT_KERNEL_RWX >> select ARCH_HAS_UBSAN_SANITIZE_ALL >> + select ARCH_HAS_VM_GET_PAGE_PROT >> select ARCH_NO_SG_CHAIN >> select ARCH_SUPPORTS_HUGETLBFS if PA20 >> select ARCH_SUPPORTS_MEMORY_FAILURE >> diff --git a/arch/parisc/include/asm/pgtable.h >> b/arch/parisc/include/asm/pgtable.h index 3e7cf882639f..80d99b2b5913 100644 >> --- a/arch/parisc/include/asm/pgtable.h >> +++ b/arch/parisc/include/asm/pgtable.h >> @@ -269,26 +269,6 @@ extern void __update_cache(pte_t pte); >> * pages. >> */ >> >> - /*xwr*/ >> -#define __P000 PAGE_NONE >> -#define __P001 PAGE_READONLY >> -#define __P010 __P000 /* copy on write */ >> -#define __P011 __P001 /* copy on write */ >> -#define __P100 PAGE_EXECREAD >> -#define __P101 PAGE_EXECREAD >> -#define __P110 __P100 /* copy on write */ >> -#define __P111 __P101 /* copy on write */ >> - >> -#define __S000 PAGE_NONE >> -#define __S001 PAGE_READONLY >> -#define __S010 PAGE_WRITEONLY >> -#define __S011 PAGE_SHARED >> -#define __S100 PAGE_EXECREAD >> -#define __S101 PAGE_EXECREAD >> -#define __S110 PAGE_RWX >> -#define __S111 PAGE_RWX >> - >> - >> extern pgd_t swapper_pg_dir[]; /* declared in init_task.c */ >> >> /* initial page tables for 0-8MB for kernel */ >> diff --git a/arch/parisc/mm/init.c b/arch/parisc/mm/init.c >> index 1ae31db9988f..c8316e97e1a2 100644 >> --- a/arch/parisc/mm/init.c >> +++ b/arch/parisc/mm/init.c >> @@ -866,3 +866,44 @@ void flush_tlb_all(void) >> spin_unlock(&sid_lock); >> } >> #endif >> + >> +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_NONE; >> + case VM_READ | VM_WRITE: >> + return PAGE_READONLY; > This looks extremely strange. It probably is correct when it comes to CoW, how > about including the comment that was in the original definitions for the cases > where CoW is expected? > Assuming that you suggest the following four comments here, sure will add them. -#define __P000 PAGE_NONE -#define __P001 PAGE_READONLY -#define __P010 __P000 /* copy on write */ -#define __P011 __P001 /* copy on write */ -#define __P100 PAGE_EXECREAD -#define __P101 PAGE_EXECREAD -#define __P110 __P100 /* copy on write */ -#define __P111 __P101 /* copy on write */