[RFC][PATCH 1/2] uio: allow drivers to override the pgprot for mmap
From: Kumar Gala <hidden>
Date: 2011-10-28 15:50:45
Also in:
lkml
Subsystem:
the rest, userspace i/o (uio) · Maintainers:
Linus Torvalds, Greg Kroah-Hartman
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 <redacted> Signed-off-by: Geoff Thorpe <redacted> --- 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
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1.7.3.4