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[209.85.220.65]) by mx.google.com with SMTPS id c4sor65439474plo.34.2019.07.26.12.42.26 for (Google Transport Security); Fri, 26 Jul 2019 12:42:26 -0700 (PDT) Received-SPF: pass (google.com: domain of linux.bhar@gmail.com designates 209.85.220.65 as permitted sender) client-ip=209.85.220.65; Authentication-Results: mx.google.com; dkim=pass header.i=@gmail.com header.s=20161025 header.b=pvb4XMoR; spf=pass (google.com: domain of linux.bhar@gmail.com designates 209.85.220.65 as permitted sender) smtp.mailfrom=linux.bhar@gmail.com; dmarc=pass (p=NONE sp=QUARANTINE dis=NONE) header.from=gmail.com DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=gmail.com; s=20161025; h=from:to:cc:subject:date:message-id:in-reply-to:references :mime-version:content-transfer-encoding; bh=iss5MtLqPNhVnioRpTHWsrM6bPKJLDIqo033J1yVDcM=; b=pvb4XMoRFI3vsJl94sgvoHP/3L0Qepy+ejBQoFocThb2yu7LfHELYTa6G30aRmCC9W +NbGZpskxV3iU7pPyRlHjPdnNB8WE7DuWQMm5TtV5Y5eEUyNyes2h2RwMVlQIF0N4ueO ucdd2Rd0G7dheEC1quI7hOgoln5Wa3gGbAaybSo2A6La3L+plFQGI7doXzNMxa9FgAXK +rwneYJlM34N+4aNQgsa/mrXtpgVVomftfd1ll3EBc7eBoNbDhwnwuYuX91+8MnXBXBa fuMbsZUSqjjT4iYEE8OjLIpHaACJMVUEMi25tFyMP9sqfIfMYCad7iXRDSRECwJuZbQj c42A== X-Google-Smtp-Source: APXvYqw/jaznBgDNukiE2GcNJbRxsJDEYzeWOiNNNvV/tzrutqH9zyoszrSjvdNRmthnNGT+UvJlbQ== X-Received: by 2002:a17:902:9004:: with SMTP id a4mr98378377plp.109.1564170146570; Fri, 26 Jul 2019 12:42:26 -0700 (PDT) Received: from bharath12345-Inspiron-5559 ([103.110.42.33]) by smtp.gmail.com with ESMTPSA id a3sm62334301pje.3.2019.07.26.12.42.25 (version=TLS1 cipher=ECDHE-RSA-AES128-SHA bits=128/128); Fri, 26 Jul 2019 12:42:26 -0700 (PDT) From: Bharath Vedartham To: sivanich@sgi.com, arnd@arndb.de Cc: ira.weiny@intel.com, jhubbard@nvidia.com, jglisse@redhat.com, gregkh@linuxfoundation.org, william.kucharski@oracle.com, hch@lst.de, linux-kernel@vger.kernel.org, linux-mm@kvack.org, Bharath Vedartham Subject: [PATCH v3 1/1] sgi-gru: Remove *pte_lookup functions Date: Sat, 27 Jul 2019 01:12:00 +0530 Message-Id: <1564170120-11882-2-git-send-email-linux.bhar@gmail.com> X-Mailer: git-send-email 2.7.4 In-Reply-To: <1564170120-11882-1-git-send-email-linux.bhar@gmail.com> References: <1564170120-11882-1-git-send-email-linux.bhar@gmail.com> MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit X-Bogosity: Ham, tests=bogofilter, spamicity=0.000000, version=1.2.4 Sender: owner-linux-mm@kvack.org Precedence: bulk X-Loop: owner-majordomo@kvack.org List-ID: The *pte_lookup functions can be removed and be easily replaced with get_user_pages_fast functions. In the case of atomic lookup, __get_user_pages_fast is used which does not fall back to slow get_user_pages. get_user_pages_fast on the other hand tries to use __get_user_pages_fast but fallbacks to slow get_user_pages if __get_user_pages_fast fails. Also unnecessary ifdefs to check for CONFIG_HUGETLB is removed as the check is redundant. Cc: Ira Weiny Cc: John Hubbard Cc: Jérôme Glisse Cc: Greg Kroah-Hartman Cc: Dimitri Sivanich Cc: Arnd Bergmann Cc: William Kucharski Cc: Christoph Hellwig Cc: linux-kernel@vger.kernel.org Cc: linux-mm@kvack.org Reviewed-by: Ira Weiny Reviewed-by: John Hubbard Reviewed-by: William Kucharski Signed-off-by: Bharath Vedartham --- This is a fold of the 3 patches in the previous patch series. The review tags were given to the individual patches. --- drivers/misc/sgi-gru/grufault.c | 114 +++++++++------------------------------- 1 file changed, 25 insertions(+), 89 deletions(-) diff --git a/drivers/misc/sgi-gru/grufault.c b/drivers/misc/sgi-gru/grufault.c index 4b713a8..c1258ea 100644 --- a/drivers/misc/sgi-gru/grufault.c +++ b/drivers/misc/sgi-gru/grufault.c @@ -166,96 +166,20 @@ static void get_clear_fault_map(struct gru_state *gru, } /* - * Atomic (interrupt context) & non-atomic (user context) functions to - * convert a vaddr into a physical address. The size of the page - * is returned in pageshift. - * returns: - * 0 - successful - * < 0 - error code - * 1 - (atomic only) try again in non-atomic context - */ -static int non_atomic_pte_lookup(struct vm_area_struct *vma, - unsigned long vaddr, int write, - unsigned long *paddr, int *pageshift) -{ - struct page *page; - -#ifdef CONFIG_HUGETLB_PAGE - *pageshift = is_vm_hugetlb_page(vma) ? HPAGE_SHIFT : PAGE_SHIFT; -#else - *pageshift = PAGE_SHIFT; -#endif - if (get_user_pages(vaddr, 1, write ? FOLL_WRITE : 0, &page, NULL) <= 0) - return -EFAULT; - *paddr = page_to_phys(page); - put_page(page); - return 0; -} - -/* - * atomic_pte_lookup + * mmap_sem is already helod on entry to this function. This guarantees + * existence of the page tables. * - * Convert a user virtual address to a physical address * Only supports Intel large pages (2MB only) on x86_64. - * ZZZ - hugepage support is incomplete - * - * NOTE: mmap_sem is already held on entry to this function. This - * guarantees existence of the page tables. + * ZZZ - hugepage support is incomplete. */ -static int atomic_pte_lookup(struct vm_area_struct *vma, unsigned long vaddr, - int write, unsigned long *paddr, int *pageshift) -{ - pgd_t *pgdp; - p4d_t *p4dp; - pud_t *pudp; - pmd_t *pmdp; - pte_t pte; - - pgdp = pgd_offset(vma->vm_mm, vaddr); - if (unlikely(pgd_none(*pgdp))) - goto err; - - p4dp = p4d_offset(pgdp, vaddr); - if (unlikely(p4d_none(*p4dp))) - goto err; - - pudp = pud_offset(p4dp, vaddr); - if (unlikely(pud_none(*pudp))) - goto err; - - pmdp = pmd_offset(pudp, vaddr); - if (unlikely(pmd_none(*pmdp))) - goto err; -#ifdef CONFIG_X86_64 - if (unlikely(pmd_large(*pmdp))) - pte = *(pte_t *) pmdp; - else -#endif - pte = *pte_offset_kernel(pmdp, vaddr); - - if (unlikely(!pte_present(pte) || - (write && (!pte_write(pte) || !pte_dirty(pte))))) - return 1; - - *paddr = pte_pfn(pte) << PAGE_SHIFT; -#ifdef CONFIG_HUGETLB_PAGE - *pageshift = is_vm_hugetlb_page(vma) ? HPAGE_SHIFT : PAGE_SHIFT; -#else - *pageshift = PAGE_SHIFT; -#endif - return 0; - -err: - return 1; -} - static int gru_vtop(struct gru_thread_state *gts, unsigned long vaddr, int write, int atomic, unsigned long *gpa, int *pageshift) { struct mm_struct *mm = gts->ts_mm; struct vm_area_struct *vma; unsigned long paddr; - int ret, ps; + int ret; + struct page *page; vma = find_vma(mm, vaddr); if (!vma) @@ -263,21 +187,33 @@ static int gru_vtop(struct gru_thread_state *gts, unsigned long vaddr, /* * Atomic lookup is faster & usually works even if called in non-atomic - * context. + * context. get_user_pages_fast does atomic lookup before falling back to + * slow gup. */ rmb(); /* Must/check ms_range_active before loading PTEs */ - ret = atomic_pte_lookup(vma, vaddr, write, &paddr, &ps); - if (ret) { - if (atomic) + if (atomic) { + ret = __get_user_pages_fast(vaddr, 1, write, &page); + if (!ret) goto upm; - if (non_atomic_pte_lookup(vma, vaddr, write, &paddr, &ps)) + } else { + ret = get_user_pages_fast(vaddr, 1, write, &page); + if (!ret) goto inval; } + + paddr = page_to_phys(page); + put_user_page(page); + + if (unlikely(is_vm_hugetlb_page(vma))) + *pageshift = HPAGE_SHIFT; + else + *pageshift = PAGE_SHIFT; + if (is_gru_paddr(paddr)) goto inval; - paddr = paddr & ~((1UL << ps) - 1); - *gpa = uv_soc_phys_ram_to_gpa(paddr); - *pageshift = ps; + paddr = paddr & ~((1UL << *pageshift) - 1); + *gpa = uv_soc_phys_ram_to_gpa(paddr); + return VTOP_SUCCESS; inval: -- 2.7.4 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=-3.7 required=3.0 tests=FREEMAIL_FORGED_FROMDOMAIN, FREEMAIL_FROM,HEADER_FROM_DIFFERENT_DOMAINS,MAILING_LIST_MULTI,SPF_HELO_NONE, SPF_PASS,USER_AGENT_GIT autolearn=no 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 7BD6DC7618B for ; Sat, 27 Jul 2019 09:23:13 +0000 (UTC) Received: from kanga.kvack.org (kanga.kvack.org [205.233.56.17]) by mail.kernel.org (Postfix) with ESMTP id F2F392080C for ; 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[202.108.7.214]) by mx.google.com with SMTP id m4si22367613pgv.57.2019.07.27.02.22.40 for ; Sat, 27 Jul 2019 02:22:41 -0700 (PDT) Received-SPF: pass (google.com: domain of hdanton@sina.com designates 202.108.7.214 as permitted sender) client-ip=202.108.7.214; Authentication-Results: mx.google.com; spf=pass (google.com: domain of hdanton@sina.com designates 202.108.7.214 as permitted sender) smtp.mailfrom=hdanton@sina.com Received: from unknown (HELO localhost.localdomain)([222.131.77.31]) by sina.com with ESMTP id 5D3C17DC00003E9B; Sat, 27 Jul 2019 17:22:39 +0800 (CST) X-Sender: hdanton@sina.com X-Auth-ID: hdanton@sina.com X-SMAIL-MID: 35439950202192 From: Hillf Danton To: Bharath Vedartham Cc: sivanich@sgi.com, arnd@arndb.de, ira.weiny@intel.com, jhubbard@nvidia.com, jglisse@redhat.com, gregkh@linuxfoundation.org, william.kucharski@oracle.com, hch@lst.de, linux-kernel@vger.kernel.org, linux-mm@kvack.org Subject: Re: [PATCH v3 1/1] sgi-gru: Remove *pte_lookup functions Date: Sat, 27 Jul 2019 17:22:28 +0800 Message-Id: <1564170120-11882-2-git-send-email-linux.bhar@gmail.com> In-Reply-To: <1564170120-11882-1-git-send-email-linux.bhar@gmail.com> References: <1564170120-11882-1-git-send-email-linux.bhar@gmail.com> X-Mailer: git-send-email 2.7.4 MIME-Version: 1.0 Content-Type: text/plain; charset="UTF-8" List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Archived-At: List-Archive: List-Post: Content-Transfer-Encoding: 8bit X-Bogosity: Ham, tests=bogofilter, spamicity=0.000000, version=1.2.4 Sender: owner-linux-mm@kvack.org Precedence: bulk X-Loop: owner-majordomo@kvack.org List-ID: Message-ID: <20190727092228.XllsRDGhGOyPEWHo58xPSCPro1CpujN2jTCLitTC_pk@z> On Fri, 26 Jul 2019 12:42:26 -0700 (PDT) Bharath Vedartham wrote: > > static int gru_vtop(struct gru_thread_state *gts, unsigned long vaddr, > int write, int atomic, unsigned long *gpa, int *pageshift) > { > struct mm_struct *mm = gts->ts_mm; > struct vm_area_struct *vma; > unsigned long paddr; > - int ret, ps; > + int ret; > + struct page *page; > > vma = find_vma(mm, vaddr); > if (!vma) > @@ -263,21 +187,33 @@ static int gru_vtop(struct gru_thread_state *gts, unsigned long vaddr, > > /* > * Atomic lookup is faster & usually works even if called in non-atomic > - * context. > + * context. get_user_pages_fast does atomic lookup before falling back to > + * slow gup. > */ > rmb(); /* Must/check ms_range_active before loading PTEs */ > - ret = atomic_pte_lookup(vma, vaddr, write, &paddr, &ps); > - if (ret) { > - if (atomic) > + if (atomic) { > + ret = __get_user_pages_fast(vaddr, 1, write, &page); > + if (!ret) > goto upm; > - if (non_atomic_pte_lookup(vma, vaddr, write, &paddr, &ps)) > + } else { > + ret = get_user_pages_fast(vaddr, 1, write, &page); > + if (!ret) > goto inval; > } > + > + paddr = page_to_phys(page); You may drop find_vma() above if PageHuge(page) makes sense here. > + put_user_page(page); > + > + if (unlikely(is_vm_hugetlb_page(vma))) > + *pageshift = HPAGE_SHIFT; > + else > + *pageshift = PAGE_SHIFT; > + > if (is_gru_paddr(paddr)) > goto inval; > - paddr = paddr & ~((1UL << ps) - 1); > - *gpa = uv_soc_phys_ram_to_gpa(paddr); > - *pageshift = ps; > + paddr = paddr & ~((1UL << *pageshift) - 1); > + *gpa = uv_soc_phys_ram_to_gpa(paddr); > + > return VTOP_SUCCESS; > > inval: > -- > 2.7.4