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=-2.8 required=3.0 tests=HEADER_FROM_DIFFERENT_DOMAINS, MAILING_LIST_MULTI,SPF_PASS,USER_AGENT_GIT autolearn=ham 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 E7FFBC43334 for ; Thu, 6 Sep 2018 05:44:14 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 9FD3320659 for ; Thu, 6 Sep 2018 05:44:14 +0000 (UTC) DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org 9FD3320659 Authentication-Results: mail.kernel.org; dmarc=fail (p=none dis=none) header.from=linux.ibm.com Authentication-Results: mail.kernel.org; spf=none smtp.mailfrom=linux-kernel-owner@vger.kernel.org Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1727664AbeIFKR5 (ORCPT ); Thu, 6 Sep 2018 06:17:57 -0400 Received: from mx0a-001b2d01.pphosted.com ([148.163.156.1]:37130 "EHLO mx0a-001b2d01.pphosted.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1725850AbeIFKR4 (ORCPT ); Thu, 6 Sep 2018 06:17:56 -0400 Received: from pps.filterd (m0098393.ppops.net [127.0.0.1]) by mx0a-001b2d01.pphosted.com (8.16.0.22/8.16.0.22) with SMTP id w865hfs7010674 for ; Thu, 6 Sep 2018 01:44:12 -0400 Received: from e17.ny.us.ibm.com (e17.ny.us.ibm.com [129.33.205.207]) by mx0a-001b2d01.pphosted.com with ESMTP id 2mat7a8khr-1 (version=TLSv1.2 cipher=AES256-GCM-SHA384 bits=256 verify=NOT) for ; Thu, 06 Sep 2018 01:44:11 -0400 Received: from localhost by e17.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) Thu, 6 Sep 2018 01:44:07 -0400 Received: from b01ledav002.gho.pok.ibm.com (b01ledav002.gho.pok.ibm.com [9.57.199.107]) by b01cxnp23033.gho.pok.ibm.com (8.14.9/8.14.9/NCO v10.0) with ESMTP id w865i6Nm26804268 (version=TLSv1/SSLv3 cipher=DHE-RSA-AES256-GCM-SHA384 bits=256 verify=FAIL); Thu, 6 Sep 2018 05:44:06 GMT Received: from b01ledav002.gho.pok.ibm.com (unknown [127.0.0.1]) by IMSVA (Postfix) with ESMTP id AF770124052; Thu, 6 Sep 2018 02:44:35 -0400 (EDT) Received: from b01ledav002.gho.pok.ibm.com (unknown [127.0.0.1]) by IMSVA (Postfix) with ESMTP id 3E4C4124053; Thu, 6 Sep 2018 02:44:33 -0400 (EDT) Received: from skywalker.ibmuc.com (unknown [9.102.0.183]) by b01ledav002.gho.pok.ibm.com (Postfix) with ESMTP; Thu, 6 Sep 2018 02:44:32 -0400 (EDT) From: "Aneesh Kumar K.V" To: akpm@linux-foundation.org, Alexey Kardashevskiy , mpe@ellerman.id.au Cc: linux-mm@kvack.org, linux-kernel@vger.kernel.org, linuxppc-dev@lists.ozlabs.org, "Aneesh Kumar K.V" Subject: [RFC PATCH V2 4/4] powerpc/mm/iommu: Allow migration of cma allocated pages during mm_iommu_get Date: Thu, 6 Sep 2018 11:13:42 +0530 X-Mailer: git-send-email 2.17.1 In-Reply-To: <20180906054342.25094-1-aneesh.kumar@linux.ibm.com> References: <20180906054342.25094-1-aneesh.kumar@linux.ibm.com> X-TM-AS-GCONF: 00 x-cbid: 18090605-0040-0000-0000-0000046B12FD X-IBM-SpamModules-Scores: X-IBM-SpamModules-Versions: BY=3.00009676; HX=3.00000242; KW=3.00000007; PH=3.00000004; SC=3.00000266; SDB=6.01084227; UDB=6.00559595; IPR=6.00864226; MB=3.00023138; MTD=3.00000008; XFM=3.00000015; UTC=2018-09-06 05:44:09 X-IBM-AV-DETECTION: SAVI=unused REMOTE=unused XFE=unused x-cbparentid: 18090605-0041-0000-0000-000008723530 Message-Id: <20180906054342.25094-4-aneesh.kumar@linux.ibm.com> X-Proofpoint-Virus-Version: vendor=fsecure engine=2.50.10434:,, definitions=2018-09-06_02:,, signatures=0 X-Proofpoint-Spam-Details: rule=outbound_notspam policy=outbound score=0 priorityscore=1501 malwarescore=0 suspectscore=2 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=8.0.1-1807170000 definitions=main-1809060061 Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Current code doesn't do page migration if the page allocated is a compound page. With HugeTLB migration support, we can end up allocating hugetlb pages from CMA region. Also THP pages can be allocated from CMA region. This patch updates the code to handle compound pages correctly. This use the new helper get_user_pages_cma_migrate. It does one get_user_pages with right count, instead of doing one get_user_pages per page. That avoids reading page table multiple times. The patch also convert the hpas member of mm_iommu_table_group_mem_t to a union. We use the same storage location to store pointers to struct page. We cannot update alll the code path use struct page *, because we access hpas in real mode and we can't do that struct page * to pfn conversion in real mode. Signed-off-by: Aneesh Kumar K.V --- arch/powerpc/mm/mmu_context_iommu.c | 124 +++++++++------------------- 1 file changed, 37 insertions(+), 87 deletions(-) diff --git a/arch/powerpc/mm/mmu_context_iommu.c b/arch/powerpc/mm/mmu_context_iommu.c index f472965f7638..607acd03ab06 100644 --- a/arch/powerpc/mm/mmu_context_iommu.c +++ b/arch/powerpc/mm/mmu_context_iommu.c @@ -20,6 +20,7 @@ #include #include #include +#include static DEFINE_MUTEX(mem_list_mutex); @@ -30,8 +31,18 @@ struct mm_iommu_table_group_mem_t { atomic64_t mapped; unsigned int pageshift; u64 ua; /* userspace address */ - u64 entries; /* number of entries in hpas[] */ - u64 *hpas; /* vmalloc'ed */ + u64 entries; /* number of entries in hpages[] */ + /* + * in mm_iommu_get we temporarily use this to store + * struct page address. + * + * We need to convert ua to hpa in real mode. Make it + * simpler by storing physicall address. + */ + union { + struct page **hpages; /* vmalloc'ed */ + phys_addr_t *hpas; + }; }; static long mm_iommu_adjust_locked_vm(struct mm_struct *mm, @@ -74,63 +85,12 @@ bool mm_iommu_preregistered(struct mm_struct *mm) } EXPORT_SYMBOL_GPL(mm_iommu_preregistered); -/* - * Taken from alloc_migrate_target with changes to remove CMA allocations - */ -struct page *new_iommu_non_cma_page(struct page *page, unsigned long private) -{ - gfp_t gfp_mask = GFP_USER; - struct page *new_page; - - if (PageCompound(page)) - return NULL; - - if (PageHighMem(page)) - gfp_mask |= __GFP_HIGHMEM; - - /* - * We don't want the allocation to force an OOM if possibe - */ - new_page = alloc_page(gfp_mask | __GFP_NORETRY | __GFP_NOWARN); - return new_page; -} - -static int mm_iommu_move_page_from_cma(struct page *page) -{ - int ret = 0; - LIST_HEAD(cma_migrate_pages); - - /* Ignore huge pages for now */ - if (PageCompound(page)) - return -EBUSY; - - lru_add_drain(); - ret = isolate_lru_page(page); - if (ret) - return ret; - - list_add(&page->lru, &cma_migrate_pages); - put_page(page); /* Drop the gup reference */ - - ret = migrate_pages(&cma_migrate_pages, new_iommu_non_cma_page, - NULL, 0, MIGRATE_SYNC, MR_CONTIG_RANGE); - if (ret) { - if (!list_empty(&cma_migrate_pages)) - putback_movable_pages(&cma_migrate_pages); - } - - return 0; -} - long mm_iommu_get(struct mm_struct *mm, unsigned long ua, unsigned long entries, struct mm_iommu_table_group_mem_t **pmem) { struct mm_iommu_table_group_mem_t *mem; - long i, j, ret = 0, locked_entries = 0; + long i, ret = 0, locked_entries = 0; unsigned int pageshift; - unsigned long flags; - unsigned long cur_ua; - struct page *page = NULL; mutex_lock(&mem_list_mutex); @@ -177,47 +137,37 @@ long mm_iommu_get(struct mm_struct *mm, unsigned long ua, unsigned long entries, goto unlock_exit; } + ret = get_user_pages_cma_migrate(ua, entries, 1, mem->hpages); + if (ret != entries) { + /* free the reference taken */ + for (i = 0; i < ret; i++) + put_page(mem->hpages[i]); + + vfree(mem->hpas); + kfree(mem); + ret = -EFAULT; + goto unlock_exit; + } else + ret = 0; + + pageshift = PAGE_SHIFT; for (i = 0; i < entries; ++i) { - cur_ua = ua + (i << PAGE_SHIFT); - if (1 != get_user_pages_fast(cur_ua, - 1/* pages */, 1/* iswrite */, &page)) { - ret = -EFAULT; - for (j = 0; j < i; ++j) - put_page(pfn_to_page(mem->hpas[j] >> - PAGE_SHIFT)); - vfree(mem->hpas); - kfree(mem); - goto unlock_exit; - } + struct page *page = mem->hpages[i]; /* - * If we get a page from the CMA zone, since we are going to - * be pinning these entries, we might as well move them out - * of the CMA zone if possible. NOTE: faulting in + migration - * can be expensive. Batching can be considered later + * Allow to use larger than 64k IOMMU pages. Only do that + * if we are backed by hugetlb. */ - if (is_migrate_cma_page(page)) { - if (mm_iommu_move_page_from_cma(page)) - goto populate; - if (1 != get_user_pages_fast(cur_ua, - 1/* pages */, 1/* iswrite */, - &page)) { - ret = -EFAULT; - for (j = 0; j < i; ++j) - put_page(pfn_to_page(mem->hpas[j] >> - PAGE_SHIFT)); - vfree(mem->hpas); - kfree(mem); - goto unlock_exit; - } - } -populate: - pageshift = PAGE_SHIFT; - if (mem->pageshift > PAGE_SHIFT && PageHuge(page)) { + if ((mem->pageshift > PAGE_SHIFT) && PageHuge(page)) { struct page *head = compound_head(page); pageshift = compound_order(head) + PAGE_SHIFT; } mem->pageshift = min(mem->pageshift, pageshift); + /* + * We don't need struct page reference any more, switch + * physicall address. + */ mem->hpas[i] = page_to_pfn(page) << PAGE_SHIFT; + } atomic64_set(&mem->mapped, 1); -- 2.17.1