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 98715C43441 for ; Wed, 21 Nov 2018 09:29:02 +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 21D5A20989 for ; Wed, 21 Nov 2018 09:29:02 +0000 (UTC) DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org 21D5A20989 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 430HMJ1Zz2zF3fG for ; Wed, 21 Nov 2018 20:29:00 +1100 (AEDT) Authentication-Results: lists.ozlabs.org; dmarc=none (p=none dis=none) header.from=linux.ibm.com Authentication-Results: lists.ozlabs.org; spf=pass (mailfrom) smtp.mailfrom=linux.ibm.com (client-ip=148.163.158.5; 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 (mx0b-001b2d01.pphosted.com [148.163.158.5]) (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 430HDm0PxTzF3fC for ; Wed, 21 Nov 2018 20:23:19 +1100 (AEDT) Received: from pps.filterd (m0098413.ppops.net [127.0.0.1]) by mx0b-001b2d01.pphosted.com (8.16.0.22/8.16.0.22) with SMTP id wAL9J8iO079818 for ; Wed, 21 Nov 2018 04:23:18 -0500 Received: from e12.ny.us.ibm.com (e12.ny.us.ibm.com [129.33.205.202]) by mx0b-001b2d01.pphosted.com with ESMTP id 2nw1d90wrv-1 (version=TLSv1.2 cipher=AES256-GCM-SHA384 bits=256 verify=NOT) for ; Wed, 21 Nov 2018 04:23:17 -0500 Received: from localhost by e12.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) Wed, 21 Nov 2018 09:23:14 -0000 Received: from b01ledav002.gho.pok.ibm.com (b01ledav002.gho.pok.ibm.com [9.57.199.107]) by b01cxnp22035.gho.pok.ibm.com (8.14.9/8.14.9/NCO v10.0) with ESMTP id wAL9NDKg44826822 (version=TLSv1/SSLv3 cipher=DHE-RSA-AES256-GCM-SHA384 bits=256 verify=FAIL); Wed, 21 Nov 2018 09:23:13 GMT Received: from b01ledav002.gho.pok.ibm.com (unknown [127.0.0.1]) by IMSVA (Postfix) with ESMTP id 650F3124053; Wed, 21 Nov 2018 09:23:13 +0000 (GMT) Received: from b01ledav002.gho.pok.ibm.com (unknown [127.0.0.1]) by IMSVA (Postfix) with ESMTP id EC50D124052; Wed, 21 Nov 2018 09:23:10 +0000 (GMT) Received: from skywalker.in.ibm.com (unknown [9.124.31.179]) by b01ledav002.gho.pok.ibm.com (Postfix) with ESMTP; Wed, 21 Nov 2018 09:23:10 +0000 (GMT) From: "Aneesh Kumar K.V" To: akpm@linux-foundation.org, Michal Hocko , Alexey Kardashevskiy , mpe@ellerman.id.au, paulus@samba.org, David Gibson Subject: [PATCH V4 2/3] powerpc/mm/iommu: Allow migration of cma allocated pages during mm_iommu_get Date: Wed, 21 Nov 2018 14:52:58 +0530 X-Mailer: git-send-email 2.17.2 In-Reply-To: <20181121092259.16482-1-aneesh.kumar@linux.ibm.com> References: <20181121092259.16482-1-aneesh.kumar@linux.ibm.com> X-TM-AS-GCONF: 00 x-cbid: 18112109-0060-0000-0000-000002D6575F X-IBM-SpamModules-Scores: X-IBM-SpamModules-Versions: BY=3.00010092; HX=3.00000242; KW=3.00000007; PH=3.00000004; SC=3.00000270; SDB=6.01120588; UDB=6.00581487; IPR=6.00900709; MB=3.00024261; MTD=3.00000008; XFM=3.00000015; UTC=2018-11-21 09:23:17 X-IBM-AV-DETECTION: SAVI=unused REMOTE=unused XFE=unused x-cbparentid: 18112109-0061-0000-0000-0000474465F9 Message-Id: <20181121092259.16482-3-aneesh.kumar@linux.ibm.com> X-Proofpoint-Virus-Version: vendor=fsecure engine=2.50.10434:, , definitions=2018-11-21_04:, , 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=8.0.1-1810050000 definitions=main-1811210085 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" 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 | 120 ++++++++-------------------- 1 file changed, 35 insertions(+), 85 deletions(-) diff --git a/arch/powerpc/mm/mmu_context_iommu.c b/arch/powerpc/mm/mmu_context_iommu.c index 56c2234cc6ae..1d5161f93ce6 100644 --- a/arch/powerpc/mm/mmu_context_iommu.c +++ b/arch/powerpc/mm/mmu_context_iommu.c @@ -21,6 +21,7 @@ #include #include #include +#include static DEFINE_MUTEX(mem_list_mutex); @@ -34,8 +35,18 @@ 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, @@ -78,63 +89,14 @@ 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); @@ -181,41 +143,24 @@ 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) { + struct page *page = mem->hpages[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; - } - /* - * 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 - */ - 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 && PageCompound(page)) { pte_t *pte; struct page *head = compound_head(page); @@ -233,7 +178,12 @@ long mm_iommu_get(struct mm_struct *mm, unsigned long ua, unsigned long entries, local_irq_restore(flags); } 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); -- 2.17.2