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 2A27AC43387 for ; Tue, 8 Jan 2019 05:13:43 +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 A379F2087E for ; Tue, 8 Jan 2019 05:13:42 +0000 (UTC) DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org A379F2087E 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 43YgQX60C7zDqT9 for ; Tue, 8 Jan 2019 16:13:40 +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 43YfxF1Lh6zDqPG for ; Tue, 8 Jan 2019 15:51:44 +1100 (AEDT) Received: from pps.filterd (m0098396.ppops.net [127.0.0.1]) by mx0a-001b2d01.pphosted.com (8.16.0.22/8.16.0.22) with SMTP id x084muG2089848 for ; Mon, 7 Jan 2019 23:51:42 -0500 Received: from e11.ny.us.ibm.com (e11.ny.us.ibm.com [129.33.205.201]) by mx0a-001b2d01.pphosted.com with ESMTP id 2pvf8kqrmf-1 (version=TLSv1.2 cipher=AES256-GCM-SHA384 bits=256 verify=NOT) for ; Mon, 07 Jan 2019 23:51:42 -0500 Received: from localhost by e11.ny.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) Tue, 8 Jan 2019 04:51:38 -0000 Received: from b01ledav003.gho.pok.ibm.com (b01ledav003.gho.pok.ibm.com [9.57.199.108]) by b01cxnp23034.gho.pok.ibm.com (8.14.9/8.14.9/NCO v10.0) with ESMTP id x084pbBa25428082 (version=TLSv1/SSLv3 cipher=DHE-RSA-AES256-GCM-SHA384 bits=256 verify=FAIL); Tue, 8 Jan 2019 04:51:37 GMT Received: from b01ledav003.gho.pok.ibm.com (unknown [127.0.0.1]) by IMSVA (Postfix) with ESMTP id C0995B205F; Tue, 8 Jan 2019 04:51:37 +0000 (GMT) Received: from b01ledav003.gho.pok.ibm.com (unknown [127.0.0.1]) by IMSVA (Postfix) with ESMTP id E1814B2065; Tue, 8 Jan 2019 04:51:34 +0000 (GMT) Received: from skywalker.ibmuc.com (unknown [9.85.75.199]) by b01ledav003.gho.pok.ibm.com (Postfix) with ESMTP; Tue, 8 Jan 2019 04:51:34 +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 V6 4/4] powerpc/mm/iommu: Allow large IOMMU page size only for hugetlb backing Date: Tue, 8 Jan 2019 10:21:10 +0530 X-Mailer: git-send-email 2.20.1 In-Reply-To: <20190108045110.28597-1-aneesh.kumar@linux.ibm.com> References: <20190108045110.28597-1-aneesh.kumar@linux.ibm.com> MIME-Version: 1.0 Content-Transfer-Encoding: 8bit X-TM-AS-GCONF: 00 x-cbid: 19010804-2213-0000-0000-000003383877 X-IBM-SpamModules-Scores: X-IBM-SpamModules-Versions: BY=3.00010364; HX=3.00000242; KW=3.00000007; PH=3.00000004; SC=3.00000273; SDB=6.01143337; UDB=6.00595222; IPR=6.00923595; MB=3.00025026; MTD=3.00000008; XFM=3.00000015; UTC=2019-01-08 04:51:40 X-IBM-AV-DETECTION: SAVI=unused REMOTE=unused XFE=unused x-cbparentid: 19010804-2214-0000-0000-00005CE1EC09 Message-Id: <20190108045110.28597-5-aneesh.kumar@linux.ibm.com> X-Proofpoint-Virus-Version: vendor=fsecure engine=2.50.10434:, , definitions=2019-01-08_03:, , 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-1901080036 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 do 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 52ccab294b47..62c7590378d4 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 = 0, 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