From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1752832AbaINR3V (ORCPT ); Sun, 14 Sep 2014 13:29:21 -0400 Received: from mail-ie0-f171.google.com ([209.85.223.171]:46279 "EHLO mail-ie0-f171.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1752728AbaINR3U (ORCPT ); Sun, 14 Sep 2014 13:29:20 -0400 MIME-Version: 1.0 In-Reply-To: <20140909192910.GA7885@kroah.com> References: <1410256619-3213-1-git-send-email-ankit.jindal@linaro.org> <1410256619-3213-2-git-send-email-ankit.jindal@linaro.org> <20140909192910.GA7885@kroah.com> From: Ankit Jindal Date: Sun, 14 Sep 2014 22:58:58 +0530 Message-ID: Subject: Re: [PATCH 1/5] 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 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 10 September 2014 00:59, Greg Kroah-Hartman wrote: > On Tue, Sep 09, 2014 at 03:26:55PM +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 useful if dma-capable devices are capable of maintaining coherency >> with CPU caches becasue we can allow cacheable access to memory shared >> between such devices and user space. >> >> 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 | 22 +++++++++++++--------- >> include/linux/uio_driver.h | 7 ++++--- >> 2 files changed, 17 insertions(+), 12 deletions(-) >> >> diff --git a/drivers/uio/uio.c b/drivers/uio/uio.c >> index a673e5b..ff5b6c0 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) >> { >> struct uio_device *idev = vma->vm_private_data; >> int mi = uio_find_mem_index(vma); >> @@ -659,7 +659,9 @@ static int uio_mmap_physical(struct vm_area_struct *vma) >> return -EINVAL; >> >> vma->vm_ops = &uio_physical_vm_ops; >> - vma->vm_page_prot = pgprot_noncached(vma->vm_page_prot); >> + >> + if (!cacheable) >> + vma->vm_page_prot = pgprot_noncached(vma->vm_page_prot); >> >> /* >> * We cannot use the vm_iomap_memory() helper here, >> @@ -706,13 +708,15 @@ static int uio_mmap(struct file *filep, struct vm_area_struct *vma) >> } >> >> switch (idev->info->mem[mi].memtype) { >> - case UIO_MEM_PHYS: >> - return uio_mmap_physical(vma); >> - case UIO_MEM_LOGICAL: >> - case UIO_MEM_VIRTUAL: >> - return uio_mmap_logical(vma); >> - default: >> - return -EINVAL; >> + case UIO_MEM_PHYS: >> + return uio_mmap_physical(vma, false); >> + case UIO_MEM_LOGICAL: >> + case UIO_MEM_VIRTUAL: >> + return uio_mmap_logical(vma); >> + case UIO_MEM_PHYS_CACHE: >> + return uio_mmap_physical(vma, true); >> + default: >> + return -EINVAL; > > Please don't do code style cleanups in the same patch you are adding new > functionality. I can't take this because of this, sorry. Sure, I will separate out the patch for code style cleanups. > > greg k-h Thanks, Ankit