Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1755351AbaLHMnv (ORCPT ); Mon, 8 Dec 2014 07:43:51 -0500 Received: from mail-ig0-f181.google.com ([209.85.213.181]:62725 "EHLO mail-ig0-f181.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1754534AbaLHMnt (ORCPT ); Mon, 8 Dec 2014 07:43:49 -0500 MIME-Version: 1.0 In-Reply-To: <20141127000147.GC5313@kroah.com> References: <1416220572-13381-1-git-send-email-ankit.jindal@linaro.org> <1416220572-13381-3-git-send-email-ankit.jindal@linaro.org> <20141127000147.GC5313@kroah.com> From: Ankit Jindal Date: Mon, 8 Dec 2014 18:13:28 +0530 Message-ID: Subject: Re: [PATCH v5 2/6] uio: Add new UIO_MEM_PHYS_CACHE type for mem regions To: Greg Kroah-Hartman Cc: "linux-kernel@vger.kernel.org" , "Hans J. Koch" , "patches@apm.com" , "linux-arm-kernel@lists.infradead.org" , Rob Herring , Tushar Jagad , Russell King - ARM Linux , "devicetree@vger.kernel.org" , Guenter Roeck , Varka Bhadram , Kumar Gala , Anup Patel , =?UTF-8?Q?Andreas_F=C3=A4rber?= Content-Type: text/plain; charset=UTF-8 Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On 27 November 2014 at 05:31, Greg Kroah-Hartman wrote: > On Mon, Nov 17, 2014 at 04:06:08PM +0530, Ankit Jindal wrote: >> Currently, three types of mem regions are supported: UIO_MEM_PHYS, >> UIO_MEM_LOGICAL and UIO_MEM_VIRTUAL. Among these UIO_MEM_PHYS helps >> UIO driver export physcial memory to user space as non-cacheable >> user memory. Typcially memory-mapped registers of a device are exported >> to user space as UIO_MEM_PHYS type mem region. The UIO_MEM_PHYS type >> is not efficient if dma-capable devices are capable of maintaining coherency >> with CPU caches. > > Not efficient in what way? Sorry, I will rephrase this. > >> This patch adds new type UIO_MEM_PHYS_CACHE for mem regions to enable >> cacheable access to physical memory from user space. >> >> Signed-off-by: Ankit Jindal >> Signed-off-by: Tushar Jagad >> --- >> drivers/uio/uio.c | 11 ++++++++--- >> include/linux/uio_driver.h | 1 + >> 2 files changed, 9 insertions(+), 3 deletions(-) >> >> diff --git a/drivers/uio/uio.c b/drivers/uio/uio.c >> index 97e6444..120a84b 100644 >> --- a/drivers/uio/uio.c >> +++ b/drivers/uio/uio.c >> @@ -644,7 +644,7 @@ static const struct vm_operations_struct uio_physical_vm_ops = { >> #endif >> }; >> >> -static int uio_mmap_physical(struct vm_area_struct *vma) >> +static int uio_mmap_physical(struct vm_area_struct *vma, bool cacheable) > > I despise "bool" flags in a function, as they don't give any idea of > what is going on when you see the function being called. Please create > a new function that does this properly, with a correct name, if it's > needed. Sure, will take care of this in next revision. > > thanks, > > greg k-h Thanks, Ankit -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/