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=-9.0 required=3.0 tests=HEADER_FROM_DIFFERENT_DOMAINS, INCLUDES_PATCH,MAILING_LIST_MULTI,SIGNED_OFF_BY,SPF_PASS,USER_AGENT_GIT 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 0194AC43381 for ; Wed, 27 Feb 2019 14:50:05 +0000 (UTC) Received: from lists.ozlabs.org (lists.ozlabs.org [203.11.71.2]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by mail.kernel.org (Postfix) with ESMTPS id 7CCC420863 for ; Wed, 27 Feb 2019 14:50:04 +0000 (UTC) DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org 7CCC420863 Authentication-Results: mail.kernel.org; dmarc=fail (p=none dis=none) header.from=linux.ibm.com Authentication-Results: mail.kernel.org; spf=pass smtp.mailfrom=linuxppc-dev-bounces+linuxppc-dev=archiver.kernel.org@lists.ozlabs.org Received: from lists.ozlabs.org (lists.ozlabs.org [IPv6:2401:3900:2:1::3]) by lists.ozlabs.org (Postfix) with ESMTP id 448drV0p2fzDqN6 for ; Thu, 28 Feb 2019 01:50:02 +1100 (AEDT) Authentication-Results: lists.ozlabs.org; spf=pass (mailfrom) smtp.mailfrom=linux.ibm.com (client-ip=148.163.156.1; helo=mx0a-001b2d01.pphosted.com; envelope-from=aneesh.kumar@linux.ibm.com; receiver=) Authentication-Results: lists.ozlabs.org; dmarc=none (p=none dis=none) header.from=linux.ibm.com Received: from mx0a-001b2d01.pphosted.com (mx0a-001b2d01.pphosted.com [148.163.156.1]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by lists.ozlabs.org (Postfix) with ESMTPS id 448dpg1p77zDqJg for ; Thu, 28 Feb 2019 01:48:27 +1100 (AEDT) Received: from pps.filterd (m0098396.ppops.net [127.0.0.1]) by mx0a-001b2d01.pphosted.com (8.16.0.27/8.16.0.27) with SMTP id x1RElwDE011535 for ; Wed, 27 Feb 2019 09:48:24 -0500 Received: from e31.co.us.ibm.com (e31.co.us.ibm.com [32.97.110.149]) by mx0a-001b2d01.pphosted.com with ESMTP id 2qwuwjjnpn-1 (version=TLSv1.2 cipher=AES256-GCM-SHA384 bits=256 verify=NOT) for ; Wed, 27 Feb 2019 09:48:23 -0500 Received: from localhost by e31.co.us.ibm.com with IBM ESMTP SMTP Gateway: Authorized Use Only! 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Violators will be prosecuted; (version=TLSv1/SSLv3 cipher=AES256-GCM-SHA384 bits=256/256) Wed, 27 Feb 2019 14:48:14 -0000 Received: from b03ledav006.gho.boulder.ibm.com (b03ledav006.gho.boulder.ibm.com [9.17.130.237]) by b03cxnp08025.gho.boulder.ibm.com (8.14.9/8.14.9/NCO v10.0) with ESMTP id x1REmDtL17629292 (version=TLSv1/SSLv3 cipher=DHE-RSA-AES256-GCM-SHA384 bits=256 verify=OK); Wed, 27 Feb 2019 14:48:13 GMT Received: from b03ledav006.gho.boulder.ibm.com (unknown [127.0.0.1]) by IMSVA (Postfix) with ESMTP id 8FFB6C6059; Wed, 27 Feb 2019 14:48:13 +0000 (GMT) Received: from b03ledav006.gho.boulder.ibm.com (unknown [127.0.0.1]) by IMSVA (Postfix) with ESMTP id 45A5DC6055; Wed, 27 Feb 2019 14:48:10 +0000 (GMT) Received: from skywalker.ibmuc.com (unknown [9.199.49.135]) by b03ledav006.gho.boulder.ibm.com (Postfix) with ESMTP; Wed, 27 Feb 2019 14:48:09 +0000 (GMT) From: "Aneesh Kumar K.V" To: akpm@linux-foundation.org, Michal Hocko , Alexey Kardashevskiy , David Gibson , Andrea Arcangeli , mpe@ellerman.id.au Subject: [PATCH v8 4/4] powerpc/mm/iommu: Allow large IOMMU page size only for hugetlb backing Date: Wed, 27 Feb 2019 20:17:36 +0530 X-Mailer: git-send-email 2.20.1 In-Reply-To: <20190227144736.5872-1-aneesh.kumar@linux.ibm.com> References: <20190227144736.5872-1-aneesh.kumar@linux.ibm.com> MIME-Version: 1.0 Content-Transfer-Encoding: 8bit X-TM-AS-GCONF: 00 x-cbid: 19022714-8235-0000-0000-00000E661291 X-IBM-SpamModules-Scores: X-IBM-SpamModules-Versions: BY=3.00010674; HX=3.00000242; KW=3.00000007; PH=3.00000004; SC=3.00000281; SDB=6.01167143; UDB=6.00609716; IPR=6.00947753; MB=3.00025765; MTD=3.00000008; XFM=3.00000015; UTC=2019-02-27 14:48:17 X-IBM-AV-DETECTION: SAVI=unused REMOTE=unused XFE=unused x-cbparentid: 19022714-8236-0000-0000-0000449E73C8 Message-Id: <20190227144736.5872-5-aneesh.kumar@linux.ibm.com> X-Proofpoint-Virus-Version: vendor=fsecure engine=2.50.10434:, , definitions=2019-02-27_10:, , signatures=0 X-Proofpoint-Spam-Details: rule=outbound_notspam policy=outbound score=0 priorityscore=1501 malwarescore=0 suspectscore=0 phishscore=0 bulkscore=0 spamscore=0 clxscore=1015 lowpriorityscore=0 mlxscore=0 impostorscore=0 mlxlogscore=999 adultscore=0 classifier=spam adjust=0 reason=mlx scancount=1 engine=8.0.1-1810050000 definitions=main-1902270100 X-BeenThere: linuxppc-dev@lists.ozlabs.org X-Mailman-Version: 2.1.29 Precedence: list List-Id: Linux on PowerPC Developers Mail List List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Cc: linux-mm@kvack.org, linuxppc-dev@lists.ozlabs.org, linux-kernel@vger.kernel.org, "Aneesh Kumar K.V" Errors-To: linuxppc-dev-bounces+linuxppc-dev=archiver.kernel.org@lists.ozlabs.org Sender: "Linuxppc-dev" THP pages can get split during different code paths. An incremented reference count does imply we will not split the compound page. But the pmd entry can be converted to level 4 pte entries. Keep the code simpler by allowing large IOMMU page size only if the guest ram is backed by hugetlb pages. Signed-off-by: Aneesh Kumar K.V --- arch/powerpc/mm/mmu_context_iommu.c | 24 +++++++----------------- 1 file changed, 7 insertions(+), 17 deletions(-) diff --git a/arch/powerpc/mm/mmu_context_iommu.c b/arch/powerpc/mm/mmu_context_iommu.c index 85b4e9f5c615..e7a9c4f6bfca 100644 --- a/arch/powerpc/mm/mmu_context_iommu.c +++ b/arch/powerpc/mm/mmu_context_iommu.c @@ -98,8 +98,6 @@ static long mm_iommu_do_alloc(struct mm_struct *mm, unsigned long ua, struct mm_iommu_table_group_mem_t *mem; long i, ret, locked_entries = 0; unsigned int pageshift; - unsigned long flags; - unsigned long cur_ua; mutex_lock(&mem_list_mutex); @@ -167,22 +165,14 @@ static long mm_iommu_do_alloc(struct mm_struct *mm, unsigned long ua, for (i = 0; i < entries; ++i) { struct page *page = mem->hpages[i]; - cur_ua = ua + (i << PAGE_SHIFT); - if (mem->pageshift > PAGE_SHIFT && PageCompound(page)) { - pte_t *pte; + /* + * Allow to use larger than 64k IOMMU pages. Only do that + * if we are backed by hugetlb. + */ + if ((mem->pageshift > PAGE_SHIFT) && PageHuge(page)) { struct page *head = compound_head(page); - unsigned int compshift = compound_order(head); - unsigned int pteshift; - - local_irq_save(flags); /* disables as well */ - pte = find_linux_pte(mm->pgd, cur_ua, NULL, &pteshift); - - /* Double check it is still the same pinned page */ - if (pte && pte_page(*pte) == head && - pteshift == compshift + PAGE_SHIFT) - pageshift = max_t(unsigned int, pteshift, - PAGE_SHIFT); - local_irq_restore(flags); + + pageshift = compound_order(head) + PAGE_SHIFT; } mem->pageshift = min(mem->pageshift, pageshift); /* -- 2.20.1