[PATCH] UIO: Allow a UIO driver to override the default pgprot when we mmap
From: Kumar Gala <hidden>
Date: 2011-10-12 14:43:48
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 the correct flags for the address space. Provide a means for the kernel side UIO driver to override the flags without having to implement its own full mmap callback. Signed-off-by: Kumar Gala <redacted> --- drivers/uio/uio.c | 6 +++++- include/linux/uio_driver.h | 2 ++ 2 files changed, 7 insertions(+), 1 deletions(-)
diff --git a/drivers/uio/uio.c b/drivers/uio/uio.c
index d2efe82..88f4444 100644
--- a/drivers/uio/uio.c
+++ b/drivers/uio/uio.c@@ -656,7 +656,11 @@ 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->mem[mi].set_pgprot) + vma->vm_page_prot = + idev->info->mem[mi].set_pgprot(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 665517c..4c618cd 100644
--- a/include/linux/uio_driver.h
+++ b/include/linux/uio_driver.h@@ -28,6 +28,7 @@ struct uio_map; * @memtype: type of memory addr points to * @internal_addr: ioremap-ped version of addr, for driver internal use * @map: for use by the UIO core only. + * @set_pgprot: allow driver to override default(noncached) pgprot */ struct uio_mem { const char *name;
@@ -36,6 +37,7 @@ struct uio_mem { int memtype; void __iomem *internal_addr; struct uio_map *map; + pgprot_t (*set_pgprot)(pgprot_t prot); }; #define MAX_UIO_MAPS 5
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1.7.3.4