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 X-Spam-Level: X-Spam-Status: No, score=-15.3 required=3.0 tests=BAYES_00, HEADER_FROM_DIFFERENT_DOMAINS,INCLUDES_CR_TRAILER,INCLUDES_PATCH, MAILING_LIST_MULTI,NICE_REPLY_A,SPF_HELO_NONE,SPF_PASS,USER_AGENT_SANE_1 autolearn=unavailable autolearn_force=no version=3.4.0 Received: from mail.kernel.org (mail.kernel.org [198.145.29.99]) by smtp.lore.kernel.org (Postfix) with ESMTP id EB35CC433ED for ; Thu, 8 Apr 2021 05:14:14 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id BCDFF6113A for ; Thu, 8 Apr 2021 05:14:14 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S229667AbhDHFOX (ORCPT ); Thu, 8 Apr 2021 01:14:23 -0400 Received: from foss.arm.com ([217.140.110.172]:39390 "EHLO foss.arm.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S229506AbhDHFOW (ORCPT ); Thu, 8 Apr 2021 01:14:22 -0400 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 3D6251424; Wed, 7 Apr 2021 22:14:11 -0700 (PDT) Received: from [10.163.67.84] (unknown [10.163.67.84]) by usa-sjc-imap-foss1.foss.arm.com (Postfix) with ESMTPSA id 174233F73D; Wed, 7 Apr 2021 22:14:07 -0700 (PDT) From: Anshuman Khandual Subject: Re: [RFC/RFT PATCH 2/3] arm64: decouple check whether pfn is normal memory from pfn_valid() To: Mike Rapoport , linux-arm-kernel@lists.infradead.org Cc: Ard Biesheuvel , Catalin Marinas , David Hildenbrand , Marc Zyngier , Mark Rutland , Mike Rapoport , Will Deacon , kvmarm@lists.cs.columbia.edu, linux-kernel@vger.kernel.org, linux-mm@kvack.org References: <20210407172607.8812-1-rppt@kernel.org> <20210407172607.8812-3-rppt@kernel.org> Message-ID: <4a788546-b854-fd35-644a-f1d9075a9a78@arm.com> Date: Thu, 8 Apr 2021 10:44:58 +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: <20210407172607.8812-3-rppt@kernel.org> Content-Type: text/plain; charset=utf-8 Content-Language: en-US Content-Transfer-Encoding: 7bit Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On 4/7/21 10:56 PM, Mike Rapoport wrote: > From: Mike Rapoport > > The intended semantics of pfn_valid() is to verify whether there is a > struct page for the pfn in question and nothing else. Should there be a comment affirming this semantics interpretation, above the generic pfn_valid() in include/linux/mmzone.h ? > > Yet, on arm64 it is used to distinguish memory areas that are mapped in the > linear map vs those that require ioremap() to access them. > > Introduce a dedicated pfn_is_memory() to perform such check and use it > where appropriate. > > Signed-off-by: Mike Rapoport > --- > arch/arm64/include/asm/memory.h | 2 +- > arch/arm64/include/asm/page.h | 1 + > arch/arm64/kvm/mmu.c | 2 +- > arch/arm64/mm/init.c | 6 ++++++ > arch/arm64/mm/ioremap.c | 4 ++-- > arch/arm64/mm/mmu.c | 2 +- > 6 files changed, 12 insertions(+), 5 deletions(-) > > diff --git a/arch/arm64/include/asm/memory.h b/arch/arm64/include/asm/memory.h > index 0aabc3be9a75..7e77fdf71b9d 100644 > --- a/arch/arm64/include/asm/memory.h > +++ b/arch/arm64/include/asm/memory.h > @@ -351,7 +351,7 @@ static inline void *phys_to_virt(phys_addr_t x) > > #define virt_addr_valid(addr) ({ \ > __typeof__(addr) __addr = __tag_reset(addr); \ > - __is_lm_address(__addr) && pfn_valid(virt_to_pfn(__addr)); \ > + __is_lm_address(__addr) && pfn_is_memory(virt_to_pfn(__addr)); \ > }) > > void dump_mem_limit(void); > diff --git a/arch/arm64/include/asm/page.h b/arch/arm64/include/asm/page.h > index 012cffc574e8..32b485bcc6ff 100644 > --- a/arch/arm64/include/asm/page.h > +++ b/arch/arm64/include/asm/page.h > @@ -38,6 +38,7 @@ void copy_highpage(struct page *to, struct page *from); > typedef struct page *pgtable_t; > > extern int pfn_valid(unsigned long); > +extern int pfn_is_memory(unsigned long); > > #include > > diff --git a/arch/arm64/kvm/mmu.c b/arch/arm64/kvm/mmu.c > index 8711894db8c2..ad2ea65a3937 100644 > --- a/arch/arm64/kvm/mmu.c > +++ b/arch/arm64/kvm/mmu.c > @@ -85,7 +85,7 @@ void kvm_flush_remote_tlbs(struct kvm *kvm) > > static bool kvm_is_device_pfn(unsigned long pfn) > { > - return !pfn_valid(pfn); > + return !pfn_is_memory(pfn); > } > > /* > diff --git a/arch/arm64/mm/init.c b/arch/arm64/mm/init.c > index 3685e12aba9b..258b1905ed4a 100644 > --- a/arch/arm64/mm/init.c > +++ b/arch/arm64/mm/init.c > @@ -258,6 +258,12 @@ int pfn_valid(unsigned long pfn) > } > EXPORT_SYMBOL(pfn_valid); > > +int pfn_is_memory(unsigned long pfn) > +{ > + return memblock_is_map_memory(PFN_PHYS(pfn)); > +} > +EXPORT_SYMBOL(pfn_is_memory);> + Should not this be generic though ? There is nothing platform or arm64 specific in here. Wondering as pfn_is_memory() just indicates that the pfn is linear mapped, should not it be renamed as pfn_is_linear_memory() instead ? Regardless, it's fine either way. > static phys_addr_t memory_limit = PHYS_ADDR_MAX; > > /* > diff --git a/arch/arm64/mm/ioremap.c b/arch/arm64/mm/ioremap.c > index b5e83c46b23e..82a369b22ef5 100644 > --- a/arch/arm64/mm/ioremap.c > +++ b/arch/arm64/mm/ioremap.c > @@ -43,7 +43,7 @@ static void __iomem *__ioremap_caller(phys_addr_t phys_addr, size_t size, > /* > * Don't allow RAM to be mapped. > */ > - if (WARN_ON(pfn_valid(__phys_to_pfn(phys_addr)))) > + if (WARN_ON(pfn_is_memory(__phys_to_pfn(phys_addr)))) > return NULL; > > area = get_vm_area_caller(size, VM_IOREMAP, caller); > @@ -84,7 +84,7 @@ EXPORT_SYMBOL(iounmap); > void __iomem *ioremap_cache(phys_addr_t phys_addr, size_t size) > { > /* For normal memory we already have a cacheable mapping. */ > - if (pfn_valid(__phys_to_pfn(phys_addr))) > + if (pfn_is_memory(__phys_to_pfn(phys_addr))) > return (void __iomem *)__phys_to_virt(phys_addr); > > return __ioremap_caller(phys_addr, size, __pgprot(PROT_NORMAL), > diff --git a/arch/arm64/mm/mmu.c b/arch/arm64/mm/mmu.c > index 5d9550fdb9cf..038d20fe163f 100644 > --- a/arch/arm64/mm/mmu.c > +++ b/arch/arm64/mm/mmu.c > @@ -81,7 +81,7 @@ void set_swapper_pgd(pgd_t *pgdp, pgd_t pgd) > pgprot_t phys_mem_access_prot(struct file *file, unsigned long pfn, > unsigned long size, pgprot_t vma_prot) > { > - if (!pfn_valid(pfn)) > + if (!pfn_is_memory(pfn)) > return pgprot_noncached(vma_prot); > else if (file->f_flags & O_SYNC) > return pgprot_writecombine(vma_prot); >