Re: [Intel-gfx] [PATCH v2 6/6] drm/i915: make device info a const pointer to rodata

[Jani Nikula <jani.nikula@intel.com>]

On Thu, 29 Jun 2023, Tvrtko Ursulin <tvrtko.ursulin@linux.intel.com> wrote:
> On 27/06/2023 16:14, Jani Nikula wrote:
>> Finally we can get rid of the pseudo-const write-once device info, and
>> convert it into a const pointer to device info in rodata.
>> 
>> Cc: Matt Roper <matthew.d.roper@intel.com>
>> Cc: Lucas De Marchi <lucas.demarchi@intel.com>
>> Signed-off-by: Jani Nikula <jani.nikula@intel.com>
>> ---
>>   drivers/gpu/drm/i915/i915_drv.h          |  4 ++--
>>   drivers/gpu/drm/i915/intel_device_info.c | 17 ++++-------------
>>   2 files changed, 6 insertions(+), 15 deletions(-)
>> 
>> diff --git a/drivers/gpu/drm/i915/i915_drv.h b/drivers/gpu/drm/i915/i915_drv.h
>> index 8947d1201298..682ef2b5c7d5 100644
>> --- a/drivers/gpu/drm/i915/i915_drv.h
>> +++ b/drivers/gpu/drm/i915/i915_drv.h
>> @@ -203,7 +203,7 @@ struct drm_i915_private {
>>   	/* i915 device parameters */
>>   	struct i915_params params;
>>   
>> -	const struct intel_device_info __info; /* Use INTEL_INFO() to access. */
>> +	const struct intel_device_info *__info; /* Use INTEL_INFO() to access. */
>>   	struct intel_runtime_info __runtime; /* Use RUNTIME_INFO() to access. */
>>   	struct intel_driver_caps caps;
>>   
>> @@ -415,7 +415,7 @@ static inline struct intel_gt *to_gt(struct drm_i915_private *i915)
>>   	     (engine__) && (engine__)->uabi_class == (class__); \
>>   	     (engine__) = rb_to_uabi_engine(rb_next(&(engine__)->uabi_node)))
>>   
>> -#define INTEL_INFO(i915)	(&(i915)->__info)
>> +#define INTEL_INFO(i915)	((i915)->__info)
>>   #define RUNTIME_INFO(i915)	(&(i915)->__runtime)
>>   #define DISPLAY_INFO(i915)	((i915)->display.info.__device_info)
>>   #define DISPLAY_RUNTIME_INFO(i915)	(&(i915)->display.info.__runtime_info)
>> diff --git a/drivers/gpu/drm/i915/intel_device_info.c b/drivers/gpu/drm/i915/intel_device_info.c
>> index 0740922cd71f..ea0ec6174ce5 100644
>> --- a/drivers/gpu/drm/i915/intel_device_info.c
>> +++ b/drivers/gpu/drm/i915/intel_device_info.c
>> @@ -364,13 +364,6 @@ void intel_device_info_runtime_init_early(struct drm_i915_private *i915)
>>   	intel_device_info_subplatform_init(i915);
>>   }
>>   
>> -/* FIXME: Remove this, and make device info a const pointer to rodata. */
>> -static struct intel_device_info *
>> -mkwrite_device_info(struct drm_i915_private *i915)
>> -{
>> -	return (struct intel_device_info *)INTEL_INFO(i915);
>> -}
>> -
>>   static const struct intel_display_device_info no_display = {};
>>   
>>   /**
>> @@ -430,26 +423,24 @@ void intel_device_info_driver_create(struct drm_i915_private *i915,
>>   				     u16 device_id,
>>   				     const struct intel_device_info *match_info)
>>   {
>> -	struct intel_device_info *info;
>>   	struct intel_runtime_info *runtime;
>>   	u16 ver, rel, step;
>>   
>> -	/* Setup the write-once "constant" device info */
>> -	info = mkwrite_device_info(i915);
>> -	memcpy(info, match_info, sizeof(*info));
>> +	/* Setup INTEL_INFO() */
>> +	i915->__info = match_info;
>>   
>>   	/* Initialize initial runtime info from static const data and pdev. */
>>   	runtime = RUNTIME_INFO(i915);
>>   	memcpy(runtime, &INTEL_INFO(i915)->__runtime, sizeof(*runtime));
>>   
>>   	/* Probe display support */
>> -	i915->display.info.__device_info = intel_display_device_probe(i915, info->has_gmd_id,
>> +	i915->display.info.__device_info = intel_display_device_probe(i915, HAS_GMD_ID(i915),
>
> Why does intel_display_device_probe need an explicit has_gmdid when it
> could use HAS_GMD_ID itself?

I think all of the display related initialization from this function
should be moved within intel_display_device_probe() in follow-up.

> But anyway, LGTM. If it saves you some time before the other time zone 
> comes online:
>
> Reviewed-by: Tvrtko Ursulin <tvrtko.ursulin@intel.com>

Thanks,
Jani.

>
> Regards,
>
> Tvrtko
>
>>   								      &ver, &rel, &step);
>>   	memcpy(DISPLAY_RUNTIME_INFO(i915),
>>   	       &DISPLAY_INFO(i915)->__runtime_defaults,
>>   	       sizeof(*DISPLAY_RUNTIME_INFO(i915)));
>>   
>> -	if (info->has_gmd_id) {
>> +	if (HAS_GMD_ID(i915)) {
>>   		DISPLAY_RUNTIME_INFO(i915)->ip.ver = ver;
>>   		DISPLAY_RUNTIME_INFO(i915)->ip.rel = rel;
>>   		DISPLAY_RUNTIME_INFO(i915)->ip.step = step;

-- 
Jani Nikula, Intel Open Source Graphics Center