[PATCH v4 01/11] drm/xe: Simplify module initialization code

[Michal Wajdeczko]

On 7/28/2025 9:35 PM, Rodrigo Vivi wrote:
> On Sun, Jul 27, 2025 at 07:19:58PM +0200, Michal Wajdeczko wrote:
>> There is no need to have extra checks and WARN() in the helpers
>> as instead of an index of the entry with function pointers, we
>> can pass pointer to the entry which we prepare directly in the
>> main loop, that is guaranteed to be valid.
>>
>>   add/remove: 0/0 grow/shrink: 0/4 up/down: 0/-180 (-180)
>>   Function                                     old     new   delta
>>   xe_exit                                      109      79     -30
>>   cleanup_module                               109      79     -30
>>   xe_init                                      248     188     -60
>>   init_module                                  248     188     -60
>>   Total: Before=2774145, After=2773965, chg -0.01%
>>
>> Signed-off-by: Michal Wajdeczko <michal.wajdeczko at intel.com>
>> Cc: Lucas De Marchi <lucas.demarchi at intel.com>
>> ---
>>  drivers/gpu/drm/xe/xe_module.c | 27 ++++++++++-----------------
>>  1 file changed, 10 insertions(+), 17 deletions(-)
>>
>> diff --git a/drivers/gpu/drm/xe/xe_module.c b/drivers/gpu/drm/xe/xe_module.c
>> index d9391bd08194..593bc9e5851a 100644
>> --- a/drivers/gpu/drm/xe/xe_module.c
>> +++ b/drivers/gpu/drm/xe/xe_module.c
>> @@ -135,24 +135,17 @@ static const struct init_funcs init_funcs[] = {
>>  	},
>>  };
>>  
>> -static int __init xe_call_init_func(unsigned int i)
>> +static int __init xe_call_init_func(const struct init_funcs *func)
>>  {
>> -	if (WARN_ON(i >= ARRAY_SIZE(init_funcs)))
>> -		return 0;
>> -	if (!init_funcs[i].init)
>> -		return 0;
>> -
>> -	return init_funcs[i].init();
>> +	if (func->init)
>> +		return func->init();
>> +	return 0;
>>  }
>>  
>> -static void xe_call_exit_func(unsigned int i)
>> +static void xe_call_exit_func(const struct init_funcs *func)
>>  {
>> -	if (WARN_ON(i >= ARRAY_SIZE(init_funcs)))
>> -		return;
>> -	if (!init_funcs[i].exit)
>> -		return;
>> -
>> -	init_funcs[i].exit();
>> +	if (func->exit)
>> +		func->exit();
>>  }
>>  
>>  static int __init xe_init(void)
>> @@ -160,10 +153,10 @@ static int __init xe_init(void)
>>  	int err, i;
>>  
>>  	for (i = 0; i < ARRAY_SIZE(init_funcs); i++) {
>> -		err = xe_call_init_func(i);
>> +		err = xe_call_init_func(&init_funcs[i]);
> 
> perhaps we can go further and avoid this extra function calling
> directly here:
> 
> err = init_funcs[i].init();

it depends if we want to preserve support for unset .init
(I assumed it was added on purpose)

> 
>>  		if (err) {
>>  			while (i--)
>> -				xe_call_exit_func(i);
>> +				xe_call_exit_func(&init_funcs[i]);
> 
> and
> init_funcs[i].exit();
> here ?

.exit is optional, so this will have to be:

if (init_funcs[i].exit)
	init_funcs[i].exit();

but likely compiler will do  the same with current code

> 
>>  			return err;
>>  		}
>>  	}
>> @@ -176,7 +169,7 @@ static void __exit xe_exit(void)
>>  	int i;
>>  
>>  	for (i = ARRAY_SIZE(init_funcs) - 1; i >= 0; i--)
>> -		xe_call_exit_func(i);
>> +		xe_call_exit_func(&init_funcs[i]);
> 
> and here
> init_funcs[i].exit();

since .exit is optional, better to keep one helper than
duplicate code here 

> 
> But either way is fine I guess...  up to you:
> 
> Reviewed-by: Rodrigo Vivi <rodrigo.vivi at intel.com>

thanks!
> 
>>  }
>>  
>>  module_init(xe_init);
>> -- 
>> 2.47.1
>>