From nobody Thu Nov 28 22:28:18 2024 Received: from szxga02-in.huawei.com (szxga02-in.huawei.com [45.249.212.188]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by smtp.subspace.kernel.org (Postfix) with ESMTPS id D235513698F; Fri, 27 Sep 2024 10:39:35 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=45.249.212.188 ARC-Seal: i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1727433578; cv=none; b=oo/r+BrVG7vfFOFP+KLa0x2QObZQCf7pYHDm7lnYMWi3iWuSO4p7Q7DHa17MCy9jdwpiJyGdMlQ5Tw9xkhCkYaL/p1ta2eYEeJpA7rYHacFPf5CAR5FXx5W2aA730VUolQBFAZfR27JxzsRgcMkALmo3fSSJV19OpxLt8g/UZro= ARC-Message-Signature: i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1727433578; c=relaxed/simple; bh=VaqY7fSnnc+sTwn1vuPDl7W9DTLaIQlQ/kU5WCPPduA=; h=From:To:CC:Subject:Date:Message-ID:In-Reply-To:References: MIME-Version:Content-Type; b=FPiGOCuZrd8WCb7722SluUZ3tX/3rTTUXVIgjULXfAeT9fiWKi/LbrWvDrUax+Cu49+DxO1o8h3W1HhVfH6U0W4voBoIGOc7RSGJnGcPhPYWtkgbrb+ECuQPXtM7S5a0pbRTWXwWQBThgD90KNgDrlCM1dPOhOQS/hB8EddrEQc= ARC-Authentication-Results: i=1; smtp.subspace.kernel.org; dmarc=pass (p=quarantine dis=none) header.from=hisilicon.com; spf=pass smtp.mailfrom=hisilicon.com; arc=none smtp.client-ip=45.249.212.188 Authentication-Results: smtp.subspace.kernel.org; dmarc=pass (p=quarantine dis=none) header.from=hisilicon.com Authentication-Results: smtp.subspace.kernel.org; spf=pass smtp.mailfrom=hisilicon.com Received: from mail.maildlp.com (unknown [172.19.88.105]) by szxga02-in.huawei.com (SkyGuard) with ESMTP id 4XFRjl0HHKzWf0n; Fri, 27 Sep 2024 18:37:15 +0800 (CST) Received: from kwepemf100018.china.huawei.com (unknown [7.202.181.17]) by mail.maildlp.com (Postfix) with ESMTPS id 23D7F140393; Fri, 27 Sep 2024 18:39:33 +0800 (CST) Received: from localhost.localdomain (10.90.30.45) by kwepemf100018.china.huawei.com (7.202.181.17) with Microsoft SMTP Server (version=TLS1_2, cipher=TLS_ECDHE_RSA_WITH_AES_256_GCM_SHA384) id 15.2.1544.11; Fri, 27 Sep 2024 18:39:24 +0800 From: Junxian Huang To: , CC: , , , , Subject: [PATCH v6 for-next 1/2] RDMA/core: Provide rdma_user_mmap_disassociate() to disassociate mmap pages Date: Fri, 27 Sep 2024 18:33:22 +0800 Message-ID: <20240927103323.1897094-2-huangjunxian6@hisilicon.com> X-Mailer: git-send-email 2.30.0 In-Reply-To: <20240927103323.1897094-1-huangjunxian6@hisilicon.com> References: <20240927103323.1897094-1-huangjunxian6@hisilicon.com> Precedence: bulk X-Mailing-List: linux-kernel@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Transfer-Encoding: quoted-printable X-ClientProxiedBy: dggems703-chm.china.huawei.com (10.3.19.180) To kwepemf100018.china.huawei.com (7.202.181.17) Content-Type: text/plain; charset="utf-8" From: Chengchang Tang Provide a new api rdma_user_mmap_disassociate() for drivers to disassociate mmap pages for a device. Since drivers can now disassociate mmaps by calling this api, introduce a new disassociation_lock to specifically prevent races between this disassociation process and new mmaps. And thus the old hw_destroy_rwsem is not needed in this api. Signed-off-by: Chengchang Tang Signed-off-by: Junxian Huang --- drivers/infiniband/core/uverbs.h | 2 ++ drivers/infiniband/core/uverbs_main.c | 43 +++++++++++++++++++++++++-- include/rdma/ib_verbs.h | 8 +++++ 3 files changed, 51 insertions(+), 2 deletions(-) diff --git a/drivers/infiniband/core/uverbs.h b/drivers/infiniband/core/uve= rbs.h index 821d93c8f712..dfd2e5a86e6f 100644 --- a/drivers/infiniband/core/uverbs.h +++ b/drivers/infiniband/core/uverbs.h @@ -160,6 +160,8 @@ struct ib_uverbs_file { struct page *disassociate_page; =20 struct xarray idr; + + struct mutex disassociation_lock; }; =20 struct ib_uverbs_event { diff --git a/drivers/infiniband/core/uverbs_main.c b/drivers/infiniband/cor= e/uverbs_main.c index bc099287de9a..48b97e6c1fc6 100644 --- a/drivers/infiniband/core/uverbs_main.c +++ b/drivers/infiniband/core/uverbs_main.c @@ -76,6 +76,7 @@ static dev_t dynamic_uverbs_dev; static DEFINE_IDA(uverbs_ida); static int ib_uverbs_add_one(struct ib_device *device); static void ib_uverbs_remove_one(struct ib_device *device, void *client_da= ta); +static struct ib_client uverbs_client; =20 static char *uverbs_devnode(const struct device *dev, umode_t *mode) { @@ -217,6 +218,7 @@ void ib_uverbs_release_file(struct kref *ref) =20 if (file->disassociate_page) __free_pages(file->disassociate_page, 0); + mutex_destroy(&file->disassociation_lock); mutex_destroy(&file->umap_lock); mutex_destroy(&file->ucontext_lock); kfree(file); @@ -700,8 +702,13 @@ static int ib_uverbs_mmap(struct file *filp, struct vm= _area_struct *vma) ret =3D PTR_ERR(ucontext); goto out; } + + mutex_lock(&file->disassociation_lock); + vma->vm_ops =3D &rdma_umap_ops; ret =3D ucontext->device->ops.mmap(ucontext, vma); + + mutex_unlock(&file->disassociation_lock); out: srcu_read_unlock(&file->device->disassociate_srcu, srcu_key); return ret; @@ -723,6 +730,8 @@ static void rdma_umap_open(struct vm_area_struct *vma) /* We are racing with disassociation */ if (!down_read_trylock(&ufile->hw_destroy_rwsem)) goto out_zap; + mutex_lock(&ufile->disassociation_lock); + /* * Disassociation already completed, the VMA should already be zapped. */ @@ -734,10 +743,12 @@ static void rdma_umap_open(struct vm_area_struct *vma) goto out_unlock; rdma_umap_priv_init(priv, vma, opriv->entry); =20 + mutex_unlock(&ufile->disassociation_lock); up_read(&ufile->hw_destroy_rwsem); return; =20 out_unlock: + mutex_unlock(&ufile->disassociation_lock); up_read(&ufile->hw_destroy_rwsem); out_zap: /* @@ -821,7 +832,7 @@ void uverbs_user_mmap_disassociate(struct ib_uverbs_fil= e *ufile) { struct rdma_umap_priv *priv, *next_priv; =20 - lockdep_assert_held(&ufile->hw_destroy_rwsem); + mutex_lock(&ufile->disassociation_lock); =20 while (1) { struct mm_struct *mm =3D NULL; @@ -847,8 +858,10 @@ void uverbs_user_mmap_disassociate(struct ib_uverbs_fi= le *ufile) break; } mutex_unlock(&ufile->umap_lock); - if (!mm) + if (!mm) { + mutex_unlock(&ufile->disassociation_lock); return; + } =20 /* * The umap_lock is nested under mmap_lock since it used within @@ -878,7 +891,31 @@ void uverbs_user_mmap_disassociate(struct ib_uverbs_fi= le *ufile) mmap_read_unlock(mm); mmput(mm); } + + mutex_unlock(&ufile->disassociation_lock); +} + +/** + * rdma_user_mmap_disassociate() - Revoke mmaps for a device + * @device: device to revoke + * + * This function should be called by drivers that need to disable mmaps fo= r the + * device, for instance because it is going to be reset. + */ +void rdma_user_mmap_disassociate(struct ib_device *device) +{ + struct ib_uverbs_device *uverbs_dev =3D + ib_get_client_data(device, &uverbs_client); + struct ib_uverbs_file *ufile; + + mutex_lock(&uverbs_dev->lists_mutex); + list_for_each_entry(ufile, &uverbs_dev->uverbs_file_list, list) { + if (ufile->ucontext) + uverbs_user_mmap_disassociate(ufile); + } + mutex_unlock(&uverbs_dev->lists_mutex); } +EXPORT_SYMBOL(rdma_user_mmap_disassociate); =20 /* * ib_uverbs_open() does not need the BKL: @@ -949,6 +986,8 @@ static int ib_uverbs_open(struct inode *inode, struct f= ile *filp) mutex_init(&file->umap_lock); INIT_LIST_HEAD(&file->umaps); =20 + mutex_init(&file->disassociation_lock); + filp->private_data =3D file; list_add_tail(&file->list, &dev->uverbs_file_list); mutex_unlock(&dev->lists_mutex); diff --git a/include/rdma/ib_verbs.h b/include/rdma/ib_verbs.h index aa8ede439905..9cb8b5fe7eee 100644 --- a/include/rdma/ib_verbs.h +++ b/include/rdma/ib_verbs.h @@ -2948,6 +2948,14 @@ int rdma_user_mmap_entry_insert_range(struct ib_ucon= text *ucontext, size_t length, u32 min_pgoff, u32 max_pgoff); =20 +#if IS_ENABLED(CONFIG_INFINIBAND_USER_ACCESS) +void rdma_user_mmap_disassociate(struct ib_device *device); +#else +static inline void rdma_user_mmap_disassociate(struct ib_device *device) +{ +} +#endif + static inline int rdma_user_mmap_entry_insert_exact(struct ib_ucontext *ucontext, struct rdma_user_mmap_entry *entry, --=20 2.33.0