On 10 September 2014 00:59, Greg Kroah-Hartman
<gre...@linuxfoundation.org> 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 <ankit.jin...@linaro.org>
>> Signed-off-by: Tushar Jagad <tushar.ja...@linaro.org>
>> ---
>> 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
--
To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
the body of a message to majord...@vger.kernel.org
More majordomo info at http://vger.kernel.org/majordomo-info.html
Please read the FAQ at http://www.tux.org/lkml/
