[PATCH] drm/xe: Promote make_u64 macro to .h file

[Michal Wajdeczko]

On 14.02.2024 14:36, Jani Nikula wrote:
> On Tue, 13 Feb 2024, Rodrigo Vivi <rodrigo.vivi at intel.com> wrote:
>> On Tue, Feb 13, 2024 at 10:05:43PM +0100, Michal Wajdeczko wrote:
>>> We shouldn't hide generic macros inside .c files as this may lead
>>> to unnecessary code duplication if similar functionality is needed
>>> elsewhere.  Promote make_u64 to .h as soon we will want to reuse it.
>>
>> On the other hand, we shouldn't create an internal library of macros
>> that then start to get used indiscriminately as if it was Linux core
>> helpers.
>>
>> Changes like this was how the i915_utils.h started.
>>
>> If we really think that this macro is useful somewhere else, then
>> we should be looking to make that as part of the linux/types.h
> 
> Agreed.
> 
> Well, maybe not specifically types.h, but maybe a separate header.

My attempts to promote this to a global macro reached dead end. To move
forward please either engage in LKML [1] [2] discussions or accept this
local solution or suggest other option.

Michal

[1]
https://lore.kernel.org/lkml/20240214155408.1569-1-michal.wajdeczko@intel.com/

[2]
https://lore.kernel.org/lkml/20240214214654.1700-1-michal.wajdeczko@intel.com/


> 
> There's a need for something like this:
> 
> $ git grep "hi[ )]*<< *\(8\|16\|32\)[ )]*|.*lo"
> 
> Ditto for taking higher/lower half of a variable.
> 
> 
> BR,
> Jani.
> 
> 
>>
>>>
>>> Signed-off-by: Michal Wajdeczko <michal.wajdeczko at intel.com>
>>> ---
>>>  drivers/gpu/drm/xe/xe_gt_pagefault.c | 2 --
>>>  drivers/gpu/drm/xe/xe_macros.h       | 8 ++++++++
>>>  2 files changed, 8 insertions(+), 2 deletions(-)
>>>
>>> diff --git a/drivers/gpu/drm/xe/xe_gt_pagefault.c b/drivers/gpu/drm/xe/xe_gt_pagefault.c
>>> index c26e4fcca01e..76a018ec8136 100644
>>> --- a/drivers/gpu/drm/xe/xe_gt_pagefault.c
>>> +++ b/drivers/gpu/drm/xe/xe_gt_pagefault.c
>>> @@ -557,8 +557,6 @@ static int handle_acc(struct xe_gt *gt, struct acc *acc)
>>>  	return ret;
>>>  }
>>>  
>>> -#define make_u64(hi__, low__)  ((u64)(hi__) << 32 | (u64)(low__))
>>> -
>>>  #define ACC_MSG_LEN_DW        4
>>>  
>>>  static bool get_acc(struct acc_queue *acc_queue, struct acc *acc)
>>> diff --git a/drivers/gpu/drm/xe/xe_macros.h b/drivers/gpu/drm/xe/xe_macros.h
>>> index daf56c846d03..b79d775c737e 100644
>>> --- a/drivers/gpu/drm/xe/xe_macros.h
>>> +++ b/drivers/gpu/drm/xe/xe_macros.h
>>> @@ -7,6 +7,7 @@
>>>  #define _XE_MACROS_H_
>>>  
>>>  #include <linux/bug.h>
>>> +#include <linux/types.h>
>>>  
>>>  #define XE_WARN_ON WARN_ON
>>>  
>>> @@ -15,4 +16,11 @@
>>>  			    "Ioctl argument check failed at %s:%d: %s", \
>>>  			    __FILE__, __LINE__, #cond), 1))
>>>  
>>> +/**
>>> + * make_u64 - make u64 value from two u32 values
>>> + * @hi__: value representing upper 32 bits
>>> + * @lo__: value representing lower 32 bits
>>> + */
>>> +#define make_u64(hi__, low__)  ((u64)(hi__) << 32 | (u64)(low__))
>>> +
>>>  #endif
>>> -- 
>>> 2.43.0
>>>
>