[PATCH V2 1/5] common: bouncebuf: Permit passing custom alignment check function

[Jaehoon Chung]

On 4/6/20 7:55 PM, Marek Vasut wrote:
> On 4/6/20 4:58 AM, Jaehoon Chung wrote:
>> On 4/4/20 7:45 PM, Marek Vasut wrote:
>>> Add extended version of the bounce_buffer_start(), which permits passing in
>>> a custom alignment checker function for the buffer. This is useful e.g. on
>>> systems with various DMA restrictions and where the checker function might
>>> be more complex than a simple CPU cache alignment check.
>>>
>>> Signed-off-by: Marek Vasut <marek.vasut+renesas at gmail.com>
>>> Cc: Daniel Schwierzeck <daniel.schwierzeck at gmail.com>
>>> Cc: Masahiro Yamada <yamada.masahiro at socionext.com>
>>> Cc: Peng Fan <peng.fan at nxp.com>
>>> Cc: Simon Glass <sjg at chromium.org>
>>> Cc: Tom Rini <trini at konsulko.com>
>>> ---
>>> V2: No change
>>> ---
>>>  common/bouncebuf.c  | 20 +++++++++++++++-----
>>>  include/bouncebuf.h | 15 +++++++++++++++
>>>  2 files changed, 30 insertions(+), 5 deletions(-)
>>>
>>> diff --git a/common/bouncebuf.c b/common/bouncebuf.c
>>> index 614eb36c78..0ace152b98 100644
>>> --- a/common/bouncebuf.c
>>> +++ b/common/bouncebuf.c
>>> @@ -31,17 +31,19 @@ static int addr_aligned(struct bounce_buffer *state)
>>>  	return 1;
>>>  }
>>>  
>>> -int bounce_buffer_start(struct bounce_buffer *state, void *data,
>>> -			size_t len, unsigned int flags)
>>> +int bounce_buffer_start_extalign(struct bounce_buffer *state, void *data,
>>> +				 size_t len, unsigned int flags,
>>> +				 size_t alignment,
>>> +				 int (*addr_is_aligned)(struct bounce_buffer *state))
>>>  {
>>>  	state->user_buffer = data;
>>>  	state->bounce_buffer = data;
>>>  	state->len = len;
>>> -	state->len_aligned = roundup(len, ARCH_DMA_MINALIGN);
>>> +	state->len_aligned = roundup(len, alignment);
>>>  	state->flags = flags;
>>>  
>>> -	if (!addr_aligned(state)) {
>>> -		state->bounce_buffer = memalign(ARCH_DMA_MINALIGN,
>>> +	if (!addr_is_aligned(state)) {
>>
>> how about checking condition whether addr_is_aligned function is present or not at here?
> 
> If it's not present, then you're misusing this function.

Right, i'm misusing this function at that case. But i think that someone can do it like me.
It's just my opinion. :)

Best Regards,
Jaehoon Chung


> 
>