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 6D10BC43334 for ; Thu, 23 Jun 2022 08:38:13 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S230255AbiFWIiM (ORCPT ); Thu, 23 Jun 2022 04:38:12 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:49214 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S229838AbiFWIiL (ORCPT ); Thu, 23 Jun 2022 04:38:11 -0400 Received: from frasgout.his.huawei.com (frasgout.his.huawei.com [185.176.79.56]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id BD75A1FCEB; Thu, 23 Jun 2022 01:38:09 -0700 (PDT) Received: from fraeml702-chm.china.huawei.com (unknown [172.18.147.226]) by frasgout.his.huawei.com (SkyGuard) with ESMTP id 4LTD9f6t10z67wtW; Thu, 23 Jun 2022 16:36:06 +0800 (CST) Received: from lhreml724-chm.china.huawei.com (10.201.108.75) by fraeml702-chm.china.huawei.com (10.206.15.51) with Microsoft SMTP Server (version=TLS1_2, cipher=TLS_ECDHE_RSA_WITH_AES_128_CBC_SHA256_P256) id 15.1.2375.24; Thu, 23 Jun 2022 10:38:07 +0200 Received: from [10.195.245.183] (10.195.245.183) by lhreml724-chm.china.huawei.com (10.201.108.75) with Microsoft SMTP Server (version=TLS1_2, cipher=TLS_ECDHE_RSA_WITH_AES_128_CBC_SHA256) id 15.1.2375.24; Thu, 23 Jun 2022 09:38:06 +0100 Message-ID: Date: Thu, 23 Jun 2022 09:38:05 +0100 MIME-Version: 1.0 User-Agent: Mozilla/5.0 (Windows NT 10.0; Win64; x64; rv:91.0) Gecko/20100101 Thunderbird/91.6.1 Subject: Re: [PATCH v3 2/4] dma-iommu: Add iommu_dma_opt_mapping_size() From: John Garry To: , , CC: , , , , , , , , , , , , References: <1654507822-168026-1-git-send-email-john.garry@huawei.com> <1654507822-168026-3-git-send-email-john.garry@huawei.com> <4a3ab043-f609-22cb-895f-e67c8dd8f6ab@huawei.com> In-Reply-To: <4a3ab043-f609-22cb-895f-e67c8dd8f6ab@huawei.com> Content-Type: text/plain; charset="UTF-8"; format=flowed Content-Transfer-Encoding: 8bit X-Originating-IP: [10.195.245.183] X-ClientProxiedBy: lhreml705-chm.china.huawei.com (10.201.108.54) To lhreml724-chm.china.huawei.com (10.201.108.75) X-CFilter-Loop: Reflected Precedence: bulk List-ID: X-Mailing-List: linux-ide@vger.kernel.org On 14/06/2022 14:12, John Garry wrote: > On 06/06/2022 10:30, John Garry wrote: >> Add the IOMMU callback for DMA mapping API dma_opt_mapping_size(), which >> allows the drivers to know the optimal mapping limit and thus limit the >> requested IOVA lengths. >> >> This value is based on the IOVA rcache range limit, as IOVAs allocated >> above this limit must always be newly allocated, which may be quite slow. >> > > Can I please get some sort of ack from the IOMMU people on this one? > Another request for an ack please. Thanks, john > >> Signed-off-by: John Garry >> Reviewed-by: Damien Le Moal >> --- >>   drivers/iommu/dma-iommu.c | 6 ++++++ >>   drivers/iommu/iova.c      | 5 +++++ >>   include/linux/iova.h      | 2 ++ >>   3 files changed, 13 insertions(+) >> >> diff --git a/drivers/iommu/dma-iommu.c b/drivers/iommu/dma-iommu.c >> index f90251572a5d..9e1586447ee8 100644 >> --- a/drivers/iommu/dma-iommu.c >> +++ b/drivers/iommu/dma-iommu.c >> @@ -1459,6 +1459,11 @@ static unsigned long >> iommu_dma_get_merge_boundary(struct device *dev) >>       return (1UL << __ffs(domain->pgsize_bitmap)) - 1; >>   } >> +static size_t iommu_dma_opt_mapping_size(void) >> +{ >> +    return iova_rcache_range(); >> +} >> + >>   static const struct dma_map_ops iommu_dma_ops = { >>       .alloc            = iommu_dma_alloc, >>       .free            = iommu_dma_free, >> @@ -1479,6 +1484,7 @@ static const struct dma_map_ops iommu_dma_ops = { >>       .map_resource        = iommu_dma_map_resource, >>       .unmap_resource        = iommu_dma_unmap_resource, >>       .get_merge_boundary    = iommu_dma_get_merge_boundary, >> +    .opt_mapping_size    = iommu_dma_opt_mapping_size, >>   }; >>   /* >> diff --git a/drivers/iommu/iova.c b/drivers/iommu/iova.c >> index db77aa675145..9f00b58d546e 100644 >> --- a/drivers/iommu/iova.c >> +++ b/drivers/iommu/iova.c >> @@ -26,6 +26,11 @@ static unsigned long iova_rcache_get(struct >> iova_domain *iovad, >>   static void free_cpu_cached_iovas(unsigned int cpu, struct >> iova_domain *iovad); >>   static void free_iova_rcaches(struct iova_domain *iovad); >> +unsigned long iova_rcache_range(void) >> +{ >> +    return PAGE_SIZE << (IOVA_RANGE_CACHE_MAX_SIZE - 1); >> +} >> + >>   static int iova_cpuhp_dead(unsigned int cpu, struct hlist_node *node) >>   { >>       struct iova_domain *iovad; >> diff --git a/include/linux/iova.h b/include/linux/iova.h >> index 320a70e40233..c6ba6d95d79c 100644 >> --- a/include/linux/iova.h >> +++ b/include/linux/iova.h >> @@ -79,6 +79,8 @@ static inline unsigned long iova_pfn(struct >> iova_domain *iovad, dma_addr_t iova) >>   int iova_cache_get(void); >>   void iova_cache_put(void); >> +unsigned long iova_rcache_range(void); >> + >>   void free_iova(struct iova_domain *iovad, unsigned long pfn); >>   void __free_iova(struct iova_domain *iovad, struct iova *iova); >>   struct iova *alloc_iova(struct iova_domain *iovad, unsigned long size, >