From nobody Thu Dec 18 12:10:38 2025 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 AB6C9E728CC for ; Fri, 29 Sep 2023 17:01:45 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S233765AbjI2RBo (ORCPT ); Fri, 29 Sep 2023 13:01:44 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:55346 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S233675AbjI2RBd (ORCPT ); Fri, 29 Sep 2023 13:01:33 -0400 Received: from us-smtp-delivery-124.mimecast.com (us-smtp-delivery-124.mimecast.com [170.10.133.124]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id D90CB1B0 for ; Fri, 29 Sep 2023 10:00:45 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=redhat.com; s=mimecast20190719; t=1696006845; h=from:from:reply-to:subject:subject:date:date:message-id:message-id: to:to:cc:cc:mime-version:mime-version: content-transfer-encoding:content-transfer-encoding: in-reply-to:in-reply-to:references:references; bh=+oquGKuGwxfFoQE+GbMX8EY8O13dfuQB8zXuBNfC+6k=; b=Kt/iuFqC1I8L9ODVa/7foS9JAYvY+cHYphCQo/xEqdi/wXUDYnBT/FV2YI9ZU2pbopy35g JjpqJi7hqaU0Cgi420SLuTeGkCdZJK8ZnF2v9E1wzzfCx0u8OS20qBGpEKrUIr1m8Hihc4 Uff3c6NVL69F90rDqB0cfeRPpWwcDLo= Received: from mimecast-mx02.redhat.com (mimecast-mx02.redhat.com [66.187.233.88]) by relay.mimecast.com with ESMTP with STARTTLS (version=TLSv1.2, cipher=TLS_ECDHE_RSA_WITH_AES_256_GCM_SHA384) id us-mta-610-drVkHA9PODavbdJcMzCG8Q-1; Fri, 29 Sep 2023 13:00:43 -0400 X-MC-Unique: drVkHA9PODavbdJcMzCG8Q-1 Received: from smtp.corp.redhat.com (int-mx08.intmail.prod.int.rdu2.redhat.com [10.11.54.8]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by mimecast-mx02.redhat.com (Postfix) with ESMTPS id 1DE8F8007A4; Fri, 29 Sep 2023 17:00:43 +0000 (UTC) Received: from rhel-developer-toolbox.redhat.com (unknown [10.2.16.26]) by smtp.corp.redhat.com (Postfix) with ESMTP id 8BAF2C15BB8; Fri, 29 Sep 2023 17:00:41 +0000 (UTC) From: Chris Leech To: Greg Kroah-Hartman , Christoph Hellwig , Rasesh Mody , Ariel Elior , Sudarsana Kalluru , Manish Chopra Cc: Nilesh Javali , Manish Rangankar , Jerry Snitselaar , John Meneghini , Lee Duncan , Mike Christie , Hannes Reinecke , netdev@vger.kernel.org, linux-kernel@vger.kernel.org Subject: [PATCH 1/3] uio: introduce UIO_DMA_COHERENT type Date: Fri, 29 Sep 2023 10:00:21 -0700 Message-ID: <20230929170023.1020032-2-cleech@redhat.com> In-Reply-To: <20230929170023.1020032-1-cleech@redhat.com> References: <20230929170023.1020032-1-cleech@redhat.com> MIME-Version: 1.0 Content-Transfer-Encoding: quoted-printable X-Scanned-By: MIMEDefang 3.1 on 10.11.54.8 Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Type: text/plain; charset="utf-8" Add a UIO memtype specificially for sharing dma_alloc_coherent memory with userspace, backed by dma_mmap_coherent. Signed-off-by: Chris Leech --- drivers/uio/uio.c | 34 ++++++++++++++++++++++++++++++++++ include/linux/uio_driver.h | 12 ++++++++++-- 2 files changed, 44 insertions(+), 2 deletions(-) diff --git a/drivers/uio/uio.c b/drivers/uio/uio.c index 62082d64ece0..f8f1f7ba6378 100644 --- a/drivers/uio/uio.c +++ b/drivers/uio/uio.c @@ -24,6 +24,7 @@ #include #include #include +#include =20 #define UIO_MAX_DEVICES (1U << MINORBITS) =20 @@ -759,6 +760,36 @@ static int uio_mmap_physical(struct vm_area_struct *vm= a) vma->vm_page_prot); } =20 +static int uio_mmap_dma_coherent(struct vm_area_struct *vma) +{ + struct uio_device *idev =3D vma->vm_private_data; + int mi =3D uio_find_mem_index(vma); + struct uio_mem *mem; + int rc; + + if (mi < 0) + return -EINVAL; + mem =3D idev->info->mem + mi; + + if (mem->dma_addr & ~PAGE_MASK) + return -ENODEV; + if (vma->vm_end - vma->vm_start > mem->size) + return -EINVAL; + + /* + * UIO uses offset to index into the maps for a device. + * We need to clear vm_pgoff for dma_mmap_coherent. + */ + vma->vm_pgoff =3D 0; + rc =3D dma_mmap_coherent(mem->dma_device, + vma, + mem->virtual_addr, + mem->dma_addr, + vma->vm_end - vma->vm_start); + vma->vm_pgoff =3D mi; + return rc; +} + static int uio_mmap(struct file *filep, struct vm_area_struct *vma) { struct uio_listener *listener =3D filep->private_data; @@ -806,6 +837,9 @@ static int uio_mmap(struct file *filep, struct vm_area_= struct *vma) case UIO_MEM_VIRTUAL: ret =3D uio_mmap_logical(vma); break; + case UIO_MEM_DMA_COHERENT: + ret =3D uio_mmap_dma_coherent(vma); + break; default: ret =3D -EINVAL; } diff --git a/include/linux/uio_driver.h b/include/linux/uio_driver.h index 47c5962b876b..ede58e984658 100644 --- a/include/linux/uio_driver.h +++ b/include/linux/uio_driver.h @@ -36,11 +36,18 @@ struct uio_map; */ struct uio_mem { const char *name; - phys_addr_t addr; + union { + phys_addr_t addr; + dma_addr_t dma_addr; + }; unsigned long offs; resource_size_t size; int memtype; - void __iomem *internal_addr; + union { + void __iomem *internal_addr; + void *virtual_addr; + }; + struct device *dma_device; struct uio_map *map; }; =20 @@ -158,6 +165,7 @@ extern int __must_check #define UIO_MEM_LOGICAL 2 #define UIO_MEM_VIRTUAL 3 #define UIO_MEM_IOVA 4 +#define UIO_MEM_DMA_COHERENT 5 =20 /* defines for uio_port->porttype */ #define UIO_PORT_NONE 0 --=20 2.41.0