From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S932394AbcGOJEp (ORCPT ); Fri, 15 Jul 2016 05:04:45 -0400 Received: from mail-pf0-f170.google.com ([209.85.192.170]:33987 "EHLO mail-pf0-f170.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S932323AbcGOJEm (ORCPT ); Fri, 15 Jul 2016 05:04:42 -0400 From: Anup Patel To: "Hans J. Koch" , Greg Kroah-Hartman , Jonathan Corbet Cc: Ankit Jindal , Jan Viktorin , Rob Herring , Ray Jui , Scott Branden , linux-doc@vger.kernel.org, linux-kernel@vger.kernel.org, linux-arm-kernel@lists.infradead.org, bcm-kernel-feedback-list@broadcom.com, Anup Patel Subject: [PATCH 3/8] uio: Add new UIO_MEM_DEVICE type for mem regions Date: Fri, 15 Jul 2016 14:33:58 +0530 Message-Id: <1468573443-4670-4-git-send-email-anup.patel@broadcom.com> X-Mailer: git-send-email 1.9.1 In-Reply-To: <1468573443-4670-1-git-send-email-anup.patel@broadcom.com> References: <1468573443-4670-1-git-send-email-anup.patel@broadcom.com> Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On ARM64, the MMU supports special memory attributes for device memory/registers. Due to this we have pgprot_device() provided by asm/pgtable.h of arch/arm64. On architectures that do not have special MMU attribute for device memory/registers, the asm-generic/pgtable.h maps pgprot_device() to pgprot_noncached(). This patch introduces a new UIO mem region type UIO_MEM_DEVICE to represent device registers/memory. The UIO device drivers should prefer this new UIO mem region type for memory mapped device registers. Signed-off-by: Anup Patel --- drivers/uio/uio.c | 4 ++++ include/linux/uio_driver.h | 1 + 2 files changed, 5 insertions(+) diff --git a/drivers/uio/uio.c b/drivers/uio/uio.c index 0e53076..a00990c 100644 --- a/drivers/uio/uio.c +++ b/drivers/uio/uio.c @@ -663,6 +663,9 @@ static int uio_mmap_physical(struct vm_area_struct *vma, int memtype) case UIO_MEM_PHYS_CACHE: /* Do nothing. */ break; + case UIO_MEM_DEVICE: + vma->vm_page_prot = pgprot_device(vma->vm_page_prot); + break; default: return -EINVAL; } @@ -714,6 +717,7 @@ static int uio_mmap(struct file *filep, struct vm_area_struct *vma) switch (idev->info->mem[mi].memtype) { case UIO_MEM_PHYS: case UIO_MEM_PHYS_CACHE: + case UIO_MEM_DEVICE: return uio_mmap_physical(vma, idev->info->mem[mi].memtype); case UIO_MEM_LOGICAL: case UIO_MEM_VIRTUAL: diff --git a/include/linux/uio_driver.h b/include/linux/uio_driver.h index 31359aee..7349f95 100644 --- a/include/linux/uio_driver.h +++ b/include/linux/uio_driver.h @@ -129,6 +129,7 @@ extern void uio_event_notify(struct uio_info *info); #define UIO_MEM_LOGICAL 2 #define UIO_MEM_VIRTUAL 3 #define UIO_MEM_PHYS_CACHE 4 +#define UIO_MEM_DEVICE 5 /* defines for uio_port->porttype */ #define UIO_PORT_NONE 0 -- 1.9.1