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=-9.8 required=3.0 tests=DKIM_INVALID,DKIM_SIGNED, HEADER_FROM_DIFFERENT_DOMAINS,INCLUDES_PATCH,MAILING_LIST_MULTI,SIGNED_OFF_BY, SPF_HELO_NONE,SPF_PASS,URIBL_BLOCKED,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 36469C06510 for ; Mon, 1 Jul 2019 06:22:05 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 058EF2145D for ; Mon, 1 Jul 2019 06:22:05 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=fail reason="signature verification failed" (2048-bit key) header.d=infradead.org header.i=@infradead.org header.b="pvfk1jdk" Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1727546AbfGAGUm (ORCPT ); Mon, 1 Jul 2019 02:20:42 -0400 Received: from bombadil.infradead.org ([198.137.202.133]:48278 "EHLO bombadil.infradead.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1727542AbfGAGUl (ORCPT ); Mon, 1 Jul 2019 02:20:41 -0400 DKIM-Signature: v=1; a=rsa-sha256; q=dns/txt; c=relaxed/relaxed; d=infradead.org; s=bombadil.20170209; h=Content-Transfer-Encoding: MIME-Version:References:In-Reply-To:Message-Id:Date:Subject:Cc:To:From:Sender :Reply-To:Content-Type:Content-ID:Content-Description:Resent-Date:Resent-From :Resent-Sender:Resent-To:Resent-Cc:Resent-Message-ID:List-Id:List-Help: List-Unsubscribe:List-Subscribe:List-Post:List-Owner:List-Archive; bh=WF4tHB/Skt9G3b9J2cGNsUS+Db4fSie+CUUuGe98tR0=; b=pvfk1jdkUzEbDkGH+OR9rAHyIe kR8atU5kSv/EQToxLIjdsRba/jDPvJY79AkV5c9POhc8OEOnkOYGx3sDbU9BQX4OTpjP1OiMwNB8G Mr3B1wZ6mvB0ReFKDK9kAyOrFR3cFOU1pOOJAA2HuLhksS4VANVCw0zg1mFE13Q21vRUPTpXy0agl klOHn1A4qhv0abiLTq348XVdq3wl/B8i7Pzq6GmWavPxglIVnsTMy1yx8Hd9yBWwpnQDb2cCQUB5/ Of51BOJ0vhGHXiGXtGHuj8RzNUSqCPrQXBAMst2TA75JLvCwMCyYDnCASQb0SyEWfjXv+/n3G60Re 6sNUsc+Q==; Received: from [46.140.178.35] (helo=localhost) by bombadil.infradead.org with esmtpsa (Exim 4.92 #3 (Red Hat Linux)) id 1hhpg6-0002vW-0H; Mon, 01 Jul 2019 06:20:38 +0000 From: Christoph Hellwig To: Dan Williams , =?UTF-8?q?J=C3=A9r=C3=B4me=20Glisse?= , Jason Gunthorpe , Ben Skeggs Cc: Ira Weiny , linux-mm@kvack.org, nouveau@lists.freedesktop.org, dri-devel@lists.freedesktop.org, linux-nvdimm@lists.01.org, linux-pci@vger.kernel.org, linux-kernel@vger.kernel.org, Ralph Campbell , John Hubbard , Philip Yang Subject: [PATCH 07/22] mm/hmm: Use hmm_mirror not mm as an argument for hmm_range_register Date: Mon, 1 Jul 2019 08:20:05 +0200 Message-Id: <20190701062020.19239-8-hch@lst.de> X-Mailer: git-send-email 2.20.1 In-Reply-To: <20190701062020.19239-1-hch@lst.de> References: <20190701062020.19239-1-hch@lst.de> MIME-Version: 1.0 Content-Transfer-Encoding: 8bit X-SRS-Rewrite: SMTP reverse-path rewritten from by bombadil.infradead.org. See http://www.infradead.org/rpr.html Sender: linux-pci-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-pci@vger.kernel.org From: Jason Gunthorpe Ralph observes that hmm_range_register() can only be called by a driver while a mirror is registered. Make this clear in the API by passing in the mirror structure as a parameter. This also simplifies understanding the lifetime model for struct hmm, as the hmm pointer must be valid as part of a registered mirror so all we need in hmm_register_range() is a simple kref_get. Suggested-by: Ralph Campbell Signed-off-by: Jason Gunthorpe Reviewed-by: John Hubbard Reviewed-by: Ralph Campbell Reviewed-by: Ira Weiny Reviewed-by: Christoph Hellwig Tested-by: Philip Yang --- drivers/gpu/drm/nouveau/nouveau_svm.c | 2 +- include/linux/hmm.h | 7 ++++--- mm/hmm.c | 13 ++++--------- 3 files changed, 9 insertions(+), 13 deletions(-) diff --git a/drivers/gpu/drm/nouveau/nouveau_svm.c b/drivers/gpu/drm/nouveau/nouveau_svm.c index 93ed43c413f0..8c92374afcf2 100644 --- a/drivers/gpu/drm/nouveau/nouveau_svm.c +++ b/drivers/gpu/drm/nouveau/nouveau_svm.c @@ -649,7 +649,7 @@ nouveau_svm_fault(struct nvif_notify *notify) range.values = nouveau_svm_pfn_values; range.pfn_shift = NVIF_VMM_PFNMAP_V0_ADDR_SHIFT; again: - ret = hmm_vma_fault(&range, true); + ret = hmm_vma_fault(&svmm->mirror, &range, true); if (ret == 0) { mutex_lock(&svmm->mutex); if (!hmm_vma_range_done(&range)) { diff --git a/include/linux/hmm.h b/include/linux/hmm.h index cb01cf1fa3c0..1fba6979adf4 100644 --- a/include/linux/hmm.h +++ b/include/linux/hmm.h @@ -496,7 +496,7 @@ static inline bool hmm_mirror_mm_is_alive(struct hmm_mirror *mirror) * Please see Documentation/vm/hmm.rst for how to use the range API. */ int hmm_range_register(struct hmm_range *range, - struct mm_struct *mm, + struct hmm_mirror *mirror, unsigned long start, unsigned long end, unsigned page_shift); @@ -532,7 +532,8 @@ static inline bool hmm_vma_range_done(struct hmm_range *range) } /* This is a temporary helper to avoid merge conflict between trees. */ -static inline int hmm_vma_fault(struct hmm_range *range, bool block) +static inline int hmm_vma_fault(struct hmm_mirror *mirror, + struct hmm_range *range, bool block) { long ret; @@ -545,7 +546,7 @@ static inline int hmm_vma_fault(struct hmm_range *range, bool block) range->default_flags = 0; range->pfn_flags_mask = -1UL; - ret = hmm_range_register(range, range->vma->vm_mm, + ret = hmm_range_register(range, mirror, range->start, range->end, PAGE_SHIFT); if (ret) diff --git a/mm/hmm.c b/mm/hmm.c index f6956d78e3cb..22a97ada108b 100644 --- a/mm/hmm.c +++ b/mm/hmm.c @@ -914,13 +914,13 @@ static void hmm_pfns_clear(struct hmm_range *range, * Track updates to the CPU page table see include/linux/hmm.h */ int hmm_range_register(struct hmm_range *range, - struct mm_struct *mm, + struct hmm_mirror *mirror, unsigned long start, unsigned long end, unsigned page_shift) { unsigned long mask = ((1UL << page_shift) - 1UL); - struct hmm *hmm; + struct hmm *hmm = mirror->hmm; range->valid = false; range->hmm = NULL; @@ -934,20 +934,15 @@ int hmm_range_register(struct hmm_range *range, range->start = start; range->end = end; - hmm = hmm_get_or_create(mm); - if (!hmm) - return -EFAULT; - /* Check if hmm_mm_destroy() was call. */ - if (hmm->mm == NULL || hmm->dead) { - hmm_put(hmm); + if (hmm->mm == NULL || hmm->dead) return -EFAULT; - } /* Initialize range to track CPU page table updates. */ mutex_lock(&hmm->lock); range->hmm = hmm; + kref_get(&hmm->kref); list_add_rcu(&range->list, &hmm->ranges); /* -- 2.20.1