[PATCH 3/6] dma-buf: Add ioctls to allow userspace to flush

[Tiago Vignatti]

On 08/27/2015 05:03 AM, Chris Wilson wrote:
> On Wed, Aug 26, 2015 at 08:29:15PM -0300, Tiago Vignatti wrote:
>> +#ifndef _DMA_BUF_UAPI_H_
>> +#define _DMA_BUF_UAPI_H_
>> +
>> +enum dma_buf_sync_flags {
>> +	DMA_BUF_SYNC_READ = (1 << 0),
>> +	DMA_BUF_SYNC_WRITE = (2 << 0),
>> +	DMA_BUF_SYNC_RW = (3 << 0),
>> +	DMA_BUF_SYNC_START = (0 << 2),
>> +	DMA_BUF_SYNC_END = (1 << 2),
>> +
>> +	DMA_BUF_SYNC_VALID_FLAGS_MASK = DMA_BUF_SYNC_RW |
>> +		DMA_BUF_SYNC_END
>> +};
>> +
>> +/* begin/end dma-buf functions used for userspace mmap. */
>> +struct dma_buf_sync {
>> +	enum dma_buf_sync_flags flags;
>
> It is better to use explicitly sized types. And since this is not 64b
> padded, probably best to add that padding now.

ahh, I've changed it to use enum instead. If I rollback to use defines 
then do you think works better? Like this:

struct dma_buf_sync {
   __u64 flags;
};

#define DMA_BUF_SYNC_READ      (1 << 0)
#define DMA_BUF_SYNC_WRITE     (2 << 0)
#define DMA_BUF_SYNC_RW        (3 << 0)
#define DMA_BUF_SYNC_START     (0 << 2)
#define DMA_BUF_SYNC_END       (1 << 2)
#define DMA_BUF_SYNC_VALID_FLAGS_MASK \
   (DMA_BUF_SYNC_RW | DMA_BUF_SYNC_END)

#define DMA_BUF_BASE    'b'
#define DMA_BUF_IOCTL_SYNC  _IOW(DMA_BUF_BASE, 0, struct dma_buf_sync)