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 vger.kernel.org (vger.kernel.org [23.128.96.18]) by smtp.lore.kernel.org (Postfix) with ESMTP id 9D31AC433FE for ; Tue, 4 Oct 2022 15:13:15 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S229994AbiJDPNO (ORCPT ); Tue, 4 Oct 2022 11:13:14 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:37768 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S229496AbiJDPNL (ORCPT ); Tue, 4 Oct 2022 11:13:11 -0400 Received: from mx0b-001b2d01.pphosted.com (mx0b-001b2d01.pphosted.com [148.163.158.5]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 7668C5C9DA; Tue, 4 Oct 2022 08:13:10 -0700 (PDT) Received: from pps.filterd (m0098417.ppops.net [127.0.0.1]) by mx0a-001b2d01.pphosted.com (8.17.1.5/8.17.1.5) with ESMTP id 294DvmQM031944; Tue, 4 Oct 2022 15:12:57 GMT DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=ibm.com; h=message-id : date : subject : to : cc : references : from : in-reply-to : content-type : content-transfer-encoding : mime-version; s=pp1; bh=SWi0qHo2YwtSuXgjGoHT2zxbPaZGlLdxwkC+Sl8l6Mk=; b=VdYHtaIaCJTI5bo3XESVhlncvgi5qg7seVMVJjvRvvsrR22tvfAOco8V+fCM1zMPF54j /wpEt084JGqUeRMSV+xezofs8aVUOrv6zXSpqjma4MuEB6zynzP0lal5bN/e19PsZRfX MbQQTDYpDL1BH5yHvyeThSWO+xPNSNmv8XtRe9AuMjNTh6SQgHuWMfuqQBQHd7AqNF/q dVifKa4tuqYpJJJAHLclnTUl5meVxG+qhl8dQe5+/C1JnIpEPtgZqENhRP14yTYXgOWv YqEN5COfIDeLriMEgchBy/cgU9em+z/WBY87MWD35M2mZkFtq+CVbDU63UDN2QKwEgU5 Vg== Received: from ppma03wdc.us.ibm.com (ba.79.3fa9.ip4.static.sl-reverse.com [169.63.121.186]) by mx0a-001b2d01.pphosted.com (PPS) with ESMTPS id 3k0hbyudjv-1 (version=TLSv1.2 cipher=ECDHE-RSA-AES256-GCM-SHA384 bits=256 verify=NOT); Tue, 04 Oct 2022 15:12:57 +0000 Received: from pps.filterd (ppma03wdc.us.ibm.com [127.0.0.1]) by ppma03wdc.us.ibm.com (8.16.1.2/8.16.1.2) with SMTP id 294F59MI009919; Tue, 4 Oct 2022 15:12:56 GMT Received: from b01cxnp22034.gho.pok.ibm.com (b01cxnp22034.gho.pok.ibm.com [9.57.198.24]) by ppma03wdc.us.ibm.com with ESMTP id 3jxd69dmtf-1 (version=TLSv1.2 cipher=ECDHE-RSA-AES256-GCM-SHA384 bits=256 verify=NOT); Tue, 04 Oct 2022 15:12:56 +0000 Received: from smtpav04.wdc07v.mail.ibm.com ([9.208.128.116]) by b01cxnp22034.gho.pok.ibm.com (8.14.9/8.14.9/NCO v10.0) with ESMTP id 294FCtMB16909022 (version=TLSv1/SSLv3 cipher=DHE-RSA-AES256-GCM-SHA384 bits=256 verify=OK); Tue, 4 Oct 2022 15:12:55 GMT Received: from smtpav04.wdc07v.mail.ibm.com (unknown [127.0.0.1]) by IMSVA (Postfix) with ESMTP id CE61658070; Tue, 4 Oct 2022 15:12:54 +0000 (GMT) Received: from smtpav04.wdc07v.mail.ibm.com (unknown [127.0.0.1]) by IMSVA (Postfix) with ESMTP id C68AE58072; Tue, 4 Oct 2022 15:12:52 +0000 (GMT) Received: from [9.77.144.104] (unknown [9.77.144.104]) by smtpav04.wdc07v.mail.ibm.com (Postfix) with ESMTP; Tue, 4 Oct 2022 15:12:52 +0000 (GMT) Message-ID: Date: Tue, 4 Oct 2022 11:12:41 -0400 User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:102.0) Gecko/20100101 Thunderbird/102.3.0 Subject: Re: [PATCH v4 5/5] iommu/s390: Fix incorrect pgsize_bitmap Content-Language: en-US To: Robin Murphy , Niklas Schnelle , Pierre Morel , iommu@lists.linux.dev Cc: linux-s390@vger.kernel.org, borntraeger@linux.ibm.com, hca@linux.ibm.com, gor@linux.ibm.com, gerald.schaefer@linux.ibm.com, agordeev@linux.ibm.com, svens@linux.ibm.com, joro@8bytes.org, will@kernel.org, jgg@nvidia.com, linux-kernel@vger.kernel.org References: <20221004120706.2957492-1-schnelle@linux.ibm.com> <20221004120706.2957492-6-schnelle@linux.ibm.com> From: Matthew Rosato In-Reply-To: Content-Type: text/plain; charset=UTF-8 X-TM-AS-GCONF: 00 X-Proofpoint-GUID: QfCsKaHcAEwgEyTcV_GeddQf5rlspQEQ X-Proofpoint-ORIG-GUID: QfCsKaHcAEwgEyTcV_GeddQf5rlspQEQ Content-Transfer-Encoding: 8bit X-Proofpoint-UnRewURL: 0 URL was un-rewritten MIME-Version: 1.0 X-Proofpoint-Virus-Version: vendor=baseguard engine=ICAP:2.0.205,Aquarius:18.0.895,Hydra:6.0.528,FMLib:17.11.122.1 definitions=2022-10-04_06,2022-09-29_03,2022-06-22_01 X-Proofpoint-Spam-Details: rule=outbound_notspam policy=outbound score=0 mlxscore=0 lowpriorityscore=0 bulkscore=0 spamscore=0 mlxlogscore=999 priorityscore=1501 suspectscore=0 malwarescore=0 impostorscore=0 adultscore=0 phishscore=0 clxscore=1015 classifier=spam adjust=0 reason=mlx scancount=1 engine=8.12.0-2209130000 definitions=main-2210040097 Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On 10/4/22 11:02 AM, Robin Murphy wrote: > On 2022-10-04 13:07, Niklas Schnelle wrote: >> The .pgsize_bitmap property of struct iommu_ops is not a page mask but >> rather has a bit set for each size of pages the IOMMU supports. As the >> comment correctly pointed out at this moment the code only support 4K >> pages so simply use SZ_4K here. > > Unless it's already been done somewhere else, you'll want to switch over to the {map,unmap}_pages() interfaces as well to avoid taking a hit on efficiency here. The "page mask" thing was an old hack to trick the core API into making fewer map/unmap calls where the driver could map arbitrary numbers of pages at once anyway. The multi-page interfaces now do that more honestly and generally better (since they work for non-power-of-two sizes as well). Thanks for the heads up -- Niklas has some additional series coming soon as described here: https://lore.kernel.org/linux-iommu/a10424adbe01a0fd40372cbd0736d11e517951a1.camel@linux.ibm.com/ So implementing the _pages() interfaces is soon up on the roadmap. But given what you say I wonder if this patch should just wait until the series that implements {map,unmap}_pages(). > > Robin. > >> Reviewed-by: Jason Gunthorpe >> Signed-off-by: Niklas Schnelle >> --- >>   drivers/iommu/s390-iommu.c | 9 +-------- >>   1 file changed, 1 insertion(+), 8 deletions(-) >> >> diff --git a/drivers/iommu/s390-iommu.c b/drivers/iommu/s390-iommu.c >> index 94c444b909bd..6bf23e7830a2 100644 >> --- a/drivers/iommu/s390-iommu.c >> +++ b/drivers/iommu/s390-iommu.c >> @@ -12,13 +12,6 @@ >>   #include >>   #include >>   -/* >> - * Physically contiguous memory regions can be mapped with 4 KiB alignment, >> - * we allow all page sizes that are an order of 4KiB (no special large page >> - * support so far). >> - */ >> -#define S390_IOMMU_PGSIZES    (~0xFFFUL) >> - >>   static const struct iommu_ops s390_iommu_ops; >>     struct s390_domain { >> @@ -350,7 +343,7 @@ static const struct iommu_ops s390_iommu_ops = { >>       .probe_device = s390_iommu_probe_device, >>       .release_device = s390_iommu_release_device, >>       .device_group = generic_device_group, >> -    .pgsize_bitmap = S390_IOMMU_PGSIZES, >> +    .pgsize_bitmap = SZ_4K, >>       .get_resv_regions = s390_iommu_get_resv_regions, >>       .default_domain_ops = &(const struct iommu_domain_ops) { >>           .attach_dev    = s390_iommu_attach_device,