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 bombadil.infradead.org (bombadil.infradead.org [198.137.202.133]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by smtp.lore.kernel.org (Postfix) with ESMTPS id F4117C433EF for ; Mon, 24 Jan 2022 17:10:33 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; q=dns/txt; c=relaxed/relaxed; d=lists.infradead.org; s=bombadil.20210309; h=Sender: Content-Transfer-Encoding:Content-Type:List-Subscribe:List-Help:List-Post: List-Archive:List-Unsubscribe:List-Id:In-Reply-To:MIME-Version:References: Message-ID:Subject:Cc:To:From:Date:Reply-To:Content-ID:Content-Description: Resent-Date:Resent-From:Resent-Sender:Resent-To:Resent-Cc:Resent-Message-ID: List-Owner; bh=wvlLhUNMf9D+3Ty4Y6pX1ORWWeWUtzdr7uHzz8wGboE=; b=MwcuH573V9z2Yz T+g/5FdDb9TwwW82vMFDD4EBTMn9sZpzh0T0IDJfIp23qyoq6j/k/rx1ZfHA7FeB4DtRdrQCQtLE3 Op1IqcM5qprc7jHJGhSxFxKaFJMv98KO1LVrHabc8oGCoGW+07uSZ9YMLkU4VEbmPsHXulflezmSf wiNS9uAXK+pgbExfBtmDKa09VCs9Bm1tbJl6MY8P0BkEDqdT1tqHMMMIoL4kiktClPpaSxQo3Mg6D TGi+UohQD7yNESH2fGaY2T/88hBj3KBSDttJiwK11S0QpVdJdSS5aTABR9OYU2HNKSsYn/9RC5RR0 BIM99CrIypLYAn899UEA==; Received: from localhost ([::1] helo=bombadil.infradead.org) by bombadil.infradead.org with esmtp (Exim 4.94.2 #2 (Red Hat Linux)) id 1nC2qD-0048Qk-Bj; Mon, 24 Jan 2022 17:09:17 +0000 Received: from pandora.armlinux.org.uk ([2001:4d48:ad52:32c8:5054:ff:fe00:142]) by bombadil.infradead.org with esmtps (Exim 4.94.2 #2 (Red Hat Linux)) id 1nC2q9-00482B-RO for linux-arm-kernel@lists.infradead.org; Mon, 24 Jan 2022 17:09:15 +0000 DKIM-Signature: v=1; a=rsa-sha256; q=dns/txt; c=relaxed/relaxed; d=armlinux.org.uk; s=pandora-2019; h=Sender:In-Reply-To:Content-Type: MIME-Version:References:Message-ID:Subject:Cc:To:From:Date:Reply-To: Content-Transfer-Encoding:Content-ID:Content-Description:Resent-Date: Resent-From:Resent-Sender:Resent-To:Resent-Cc:Resent-Message-ID:List-Id: List-Help:List-Unsubscribe:List-Subscribe:List-Post:List-Owner:List-Archive; bh=f8r4YHtc7J3QmIdVmwsPSNX1yPV501OuwrQz7l7iC9M=; b=E826E8eJ4DAPUjKxSWUyFzUdfG CGnLDrthBvnTqbddOWDqltsR9uIXM/UhVOfd3fGy0wiKabRnmjPgeZ89znBAZOjs29OwIQK58SCBx T/MtfBCB4G/Ax2c0AUtyK2PcKoewXYQ1a4rUvcS2DgucNo7n1qDM4Fj8vElsB032HM8GRjepVFi9f fiNdKESKNXz9MYzNXCMXh+xeherGvGG/2tCq9T2DylFIZj6YFmFIBXtuWROPVOIVBFGvIkCMsaqxt e2Q7zAIdg7pzkeTmbMrVOvLY9zTuUn2vrYyxmdfdfk108qhdhpFFGF0f68mP/+wIK44XT3LH2EiW+ EOU/zekw==; Received: from shell.armlinux.org.uk ([fd8f:7570:feb6:1:5054:ff:fe00:4ec]:56840) by pandora.armlinux.org.uk with esmtpsa (TLS1.3) tls TLS_ECDHE_RSA_WITH_AES_256_GCM_SHA384 (Exim 4.94.2) (envelope-from ) id 1nC2o2-0000cg-VJ; Mon, 24 Jan 2022 17:07:02 +0000 Received: from linux by shell.armlinux.org.uk with local (Exim 4.94.2) (envelope-from ) id 1nC2nz-0001mU-V0; Mon, 24 Jan 2022 17:06:59 +0000 Date: Mon, 24 Jan 2022 17:06:59 +0000 From: "Russell King (Oracle)" To: Anshuman Khandual Cc: linux-mm@kvack.org, linux-kernel@vger.kernel.org, hch@infradead.org, akpm@linux-foundation.org, Arnd Bergmann , linux-arm-kernel@lists.infradead.org Subject: Re: [RFC V1 09/31] arm/mm: Enable ARCH_HAS_VM_GET_PAGE_PROT Message-ID: References: <1643029028-12710-1-git-send-email-anshuman.khandual@arm.com> <1643029028-12710-10-git-send-email-anshuman.khandual@arm.com> MIME-Version: 1.0 Content-Disposition: inline In-Reply-To: <1643029028-12710-10-git-send-email-anshuman.khandual@arm.com> X-CRM114-Version: 20100106-BlameMichelson ( TRE 0.8.0 (BSD) ) MR-646709E3 X-CRM114-CacheID: sfid-20220124_090913_900903_0823D724 X-CRM114-Status: GOOD ( 24.43 ) X-BeenThere: linux-arm-kernel@lists.infradead.org X-Mailman-Version: 2.1.34 Precedence: list List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7bit Sender: "linux-arm-kernel" Errors-To: linux-arm-kernel-bounces+linux-arm-kernel=archiver.kernel.org@lists.infradead.org On Mon, Jan 24, 2022 at 06:26:46PM +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. What is the fundamental advantage of this approach? > > Cc: Russell King > Cc: Arnd Bergmann > Cc: linux-arm-kernel@lists.infradead.org > Cc: linux-kernel@vger.kernel.org > Signed-off-by: Anshuman Khandual > --- > arch/arm/Kconfig | 1 + > arch/arm/include/asm/pgtable.h | 18 ------------ > arch/arm/mm/mmu.c | 50 ++++++++++++++++++++++++++++++---- > 3 files changed, 45 insertions(+), 24 deletions(-) > > diff --git a/arch/arm/Kconfig b/arch/arm/Kconfig > index fabe39169b12..c12362d20c44 100644 > --- a/arch/arm/Kconfig > +++ b/arch/arm/Kconfig > @@ -23,6 +23,7 @@ config ARM > select ARCH_HAS_SYNC_DMA_FOR_CPU if SWIOTLB || !MMU > select ARCH_HAS_TEARDOWN_DMA_OPS if MMU > select ARCH_HAS_TICK_BROADCAST if GENERIC_CLOCKEVENTS_BROADCAST > + select ARCH_HAS_VM_GET_PAGE_PROT > select ARCH_HAVE_CUSTOM_GPIO_H > select ARCH_HAVE_NMI_SAFE_CMPXCHG if CPU_V7 || CPU_V7M || CPU_V6K > select ARCH_HAS_GCOV_PROFILE_ALL > diff --git a/arch/arm/include/asm/pgtable.h b/arch/arm/include/asm/pgtable.h > index cd1f84bb40ae..ec062dd6082a 100644 > --- a/arch/arm/include/asm/pgtable.h > +++ b/arch/arm/include/asm/pgtable.h > @@ -137,24 +137,6 @@ extern pgprot_t phys_mem_access_prot(struct file *file, unsigned long pfn, > * 2) If we could do execute protection, then read is implied > * 3) write implies read permissions > */ > -#define __P000 __PAGE_NONE > -#define __P001 __PAGE_READONLY > -#define __P010 __PAGE_COPY > -#define __P011 __PAGE_COPY > -#define __P100 __PAGE_READONLY_EXEC > -#define __P101 __PAGE_READONLY_EXEC > -#define __P110 __PAGE_COPY_EXEC > -#define __P111 __PAGE_COPY_EXEC > - > -#define __S000 __PAGE_NONE > -#define __S001 __PAGE_READONLY > -#define __S010 __PAGE_SHARED > -#define __S011 __PAGE_SHARED > -#define __S100 __PAGE_READONLY_EXEC > -#define __S101 __PAGE_READONLY_EXEC > -#define __S110 __PAGE_SHARED_EXEC > -#define __S111 __PAGE_SHARED_EXEC > - > #ifndef __ASSEMBLY__ > /* > * ZERO_PAGE is a global shared page that is always zero: used > diff --git a/arch/arm/mm/mmu.c b/arch/arm/mm/mmu.c > index 274e4f73fd33..3007d07bc0e7 100644 > --- a/arch/arm/mm/mmu.c > +++ b/arch/arm/mm/mmu.c > @@ -403,6 +403,8 @@ void __set_fixmap(enum fixed_addresses idx, phys_addr_t phys, pgprot_t prot) > local_flush_tlb_kernel_range(vaddr, vaddr + PAGE_SIZE); > } > > +static pteval_t user_pgprot; > + > /* > * Adjust the PMD section entries according to the CPU in use. > */ > @@ -410,7 +412,7 @@ static void __init build_mem_type_table(void) > { > struct cachepolicy *cp; > unsigned int cr = get_cr(); > - pteval_t user_pgprot, kern_pgprot, vecs_pgprot; > + pteval_t kern_pgprot, vecs_pgprot; > int cpu_arch = cpu_architecture(); > int i; > > @@ -627,11 +629,6 @@ static void __init build_mem_type_table(void) > user_pgprot |= PTE_EXT_PXN; > #endif > > - for (i = 0; i < 16; i++) { > - pteval_t v = pgprot_val(protection_map[i]); > - protection_map[i] = __pgprot(v | user_pgprot); > - } > - > mem_types[MT_LOW_VECTORS].prot_pte |= vecs_pgprot; > mem_types[MT_HIGH_VECTORS].prot_pte |= vecs_pgprot; > > @@ -670,6 +667,47 @@ static void __init build_mem_type_table(void) > } > } > > +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 __pgprot(pgprot_val(__PAGE_NONE) | user_pgprot); > + case VM_READ: > + return __pgprot(pgprot_val(__PAGE_READONLY) | user_pgprot); > + case VM_WRITE: > + return __pgprot(pgprot_val(__PAGE_COPY) | user_pgprot); > + case VM_READ | VM_WRITE: > + return __pgprot(pgprot_val(__PAGE_COPY) | user_pgprot); > + case VM_EXEC: > + return __pgprot(pgprot_val(__PAGE_READONLY_EXEC) | user_pgprot); > + case VM_EXEC | VM_READ: > + return __pgprot(pgprot_val(__PAGE_READONLY_EXEC) | user_pgprot); > + case VM_EXEC | VM_WRITE: > + return __pgprot(pgprot_val(__PAGE_COPY_EXEC) | user_pgprot); > + case VM_EXEC | VM_READ | VM_WRITE: > + return __pgprot(pgprot_val(__PAGE_COPY_EXEC) | user_pgprot); > + case VM_SHARED: > + return __pgprot(pgprot_val(__PAGE_NONE) | user_pgprot); > + case VM_SHARED | VM_READ: > + return __pgprot(pgprot_val(__PAGE_READONLY) | user_pgprot); > + case VM_SHARED | VM_WRITE: > + return __pgprot(pgprot_val(__PAGE_SHARED) | user_pgprot); > + case VM_SHARED | VM_READ | VM_WRITE: > + return __pgprot(pgprot_val(__PAGE_SHARED) | user_pgprot); > + case VM_SHARED | VM_EXEC: > + return __pgprot(pgprot_val(__PAGE_READONLY_EXEC) | user_pgprot); > + case VM_SHARED | VM_EXEC | VM_READ: > + return __pgprot(pgprot_val(__PAGE_READONLY_EXEC) | user_pgprot); > + case VM_SHARED | VM_EXEC | VM_WRITE: > + return __pgprot(pgprot_val(__PAGE_SHARED_EXEC) | user_pgprot); > + case VM_SHARED | VM_EXEC | VM_READ | VM_WRITE: > + return __pgprot(pgprot_val(__PAGE_SHARED_EXEC) | user_pgprot); > + default: > + BUILD_BUG(); > + } > +} > +EXPORT_SYMBOL(vm_get_page_prot); > + > #ifdef CONFIG_ARM_DMA_MEM_BUFFERABLE > pgprot_t phys_mem_access_prot(struct file *file, unsigned long pfn, > unsigned long size, pgprot_t vma_prot) > -- > 2.25.1 > > -- RMK's Patch system: https://www.armlinux.org.uk/developer/patches/ FTTP is here! 40Mbps down 10Mbps up. Decent connectivity at last! _______________________________________________ linux-arm-kernel mailing list linux-arm-kernel@lists.infradead.org http://lists.infradead.org/mailman/listinfo/linux-arm-kernel