From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from gate.crashing.org (gate.crashing.org [63.228.1.57]) (using TLSv1 with cipher DHE-RSA-AES256-SHA (256/256 bits)) (Client did not present a certificate) by ozlabs.org (Postfix) with ESMTPS id BC6FBB6F77 for ; Sat, 29 Oct 2011 02:50:42 +1100 (EST) From: Kumar Gala To: hjk@hansjkoch.de Subject: [RFC][PATCH 1/2] uio: allow drivers to override the pgprot for mmap Date: Fri, 28 Oct 2011 10:50:29 -0500 Message-Id: <1319817030-23992-1-git-send-email-galak@kernel.crashing.org> Cc: Greg KH , linux-kernel@vger.kernel.org, linuxppc-dev@ozlabs.org List-Id: Linux on PowerPC Developers Mail List List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , For some devices, the default behavior of pgprot_noncached() is not appropriate for all of its mappable regions. This provides a means for the kernel side of the UIO driver to override the flags without having to implement its own full mmap callback. Signed-off-by: Kumar Gala Signed-off-by: Geoff Thorpe --- drivers/uio/uio.c | 6 +++++- include/linux/uio_driver.h | 3 +++ 2 files changed, 8 insertions(+), 1 deletions(-) diff --git a/drivers/uio/uio.c b/drivers/uio/uio.c index dc27d89..0aebe27 100644 --- a/drivers/uio/uio.c +++ b/drivers/uio/uio.c @@ -655,7 +655,11 @@ static int uio_mmap_physical(struct vm_area_struct *vma) vma->vm_flags |= VM_IO | VM_RESERVED; - vma->vm_page_prot = pgprot_noncached(vma->vm_page_prot); + if (idev->info->set_pgprot) + vma->vm_page_prot = idev->info->set_pgprot(idev->info, mi, + vma->vm_page_prot); + else + vma->vm_page_prot = pgprot_noncached(vma->vm_page_prot); return remap_pfn_range(vma, vma->vm_start, diff --git a/include/linux/uio_driver.h b/include/linux/uio_driver.h index fd99ff9..edfe7c8 100644 --- a/include/linux/uio_driver.h +++ b/include/linux/uio_driver.h @@ -80,6 +80,7 @@ struct uio_device; * @open: open operation for this uio device * @release: release operation for this uio device * @irqcontrol: disable/enable irqs when 0/1 is written to /dev/uioX + * @set_pgprot: allow driver to override default(noncached) pgprot */ struct uio_info { struct uio_device *uio_dev; @@ -95,6 +96,8 @@ struct uio_info { int (*open)(struct uio_info *info, struct inode *inode); int (*release)(struct uio_info *info, struct inode *inode); int (*irqcontrol)(struct uio_info *info, s32 irq_on); + pgprot_t (*set_pgprot)(struct uio_info *uio, unsigned int mem_idx, + pgprot_t prot); }; extern int __must_check -- 1.7.3.4