Messages in this thread Patch in this message | | | From | Kumar Gala <> | Subject | [PATCH] UIO: Allow a UIO driver to override the default pgprot when we mmap | Date | Wed, 12 Oct 2011 09:43:36 -0500 |
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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 <galak@kernel.crashing.org> --- 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 -- 1.7.3.4
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