Re: [Intel-gfx] [PATCH 2/2] drm/i915/uncore: rename i915_reg_read_ioctl intel_uncore_reg_read_ioctl

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

On Wed, 05 Jan 2022, Tvrtko Ursulin <tvrtko.ursulin@linux.intel.com> wrote:
> On 05/01/2022 10:32, Jani Nikula wrote:
>> On Wed, 05 Jan 2022, Tvrtko Ursulin <tvrtko.ursulin@linux.intel.com> wrote:
>>> On 05/01/2022 10:05, Jani Nikula wrote:
>>>> Follow the usual naming convention.
>>>
>>> But intel_uncore_ prefix usually means functions takes intel_uncore as
>>> the first argument.
>>>
>>> Maybe solution here is that i915_reg_read_ioctl does not belong in
>>> intel_uncore.c, it being the UAPI layer thing? I guess arguments could
>>> be made for either way.
>> 
>> My position is that the function and file prefixes go hand in
>> hand. You'll always know where to place a function, and you'll always
>> know where the function is to be found.
>> 
>> If you can *also* make the context argument follow the pattern, it's
>> obviously better, and indicates the division to files is working out
>> nicely. However, in a lot of cases you'll need to pass struct
>> drm_i915_private or similar as the first parameter to e.g. init
>> functions. It can't be the rigid rule.
>> 
>> I'm fine with moving the entire function somewhere else, as long as the
>> declaration is not in i915_drv.h. There's no longer a i915_drv.c, and
>> i915_drv.h should not have function declarations at all.
>
> Yes I agree it cannot be a rigid rule. I just that it feels 
> intel_uncore.[hc] is too low level to me to hold an ioctl 
> implementation, and header actually feels wrong to have the declaration. 
> Not least it is about _one_ of the uncores, while the ioctl is not 
> operating on that level, albeit undefined at the moment how exactly it 
> would work for multi-tile.
>
> Would it be too early, or unwarranted at this point, to maybe consider 
> adding i915_ioctls.[hc]?

Then the conversation would be about putting together a ton of unrelated
functions where the only thing in common is that they're an ioctl
implementation. Arguably many of them would have less in common than the
reg read ioctl has with uncore!

And when is it okay to put an ioctl in the i915_ioctls.c file and when
is it warranted to put it somewhere else? It's just a different set of
problems.

> I like the i915_ prefix of ioctls for consistency.. i915_getparam_ioctl, 
> i915_query_ioctl, i915_perf_..., i915_gem_....

The display ioctls have intel_ prefix anyway. It's the _ioctl suffix
that we use.

Again, my main driver here is cleaning up i915_drv.h. I can shove the
reg read ioctl somewhere other than intel_uncore.[ch] too. But as it
stands, the only alternative that seems better than intel_uncore.[ch] at
the moment is adding a dedicated file for a 60-line function.

BR,
Jani.


>
> Regards,
>
> Tvrtko
>
>> 
>> BR,
>> Jani.
>> 
>>>
>>> Regards,
>>>
>>> Tvrtko
>>>
>>>> Signed-off-by: Jani Nikula <jani.nikula@intel.com>
>>>> ---
>>>>    drivers/gpu/drm/i915/i915_driver.c  | 2 +-
>>>>    drivers/gpu/drm/i915/intel_uncore.c | 4 ++--
>>>>    drivers/gpu/drm/i915/intel_uncore.h | 4 ++--
>>>>    3 files changed, 5 insertions(+), 5 deletions(-)
>>>>
>>>> diff --git a/drivers/gpu/drm/i915/i915_driver.c b/drivers/gpu/drm/i915/i915_driver.c
>>>> index 95174938b160..f9a494e159dc 100644
>>>> --- a/drivers/gpu/drm/i915/i915_driver.c
>>>> +++ b/drivers/gpu/drm/i915/i915_driver.c
>>>> @@ -1805,7 +1805,7 @@ static const struct drm_ioctl_desc i915_ioctls[] = {
>>>>    	DRM_IOCTL_DEF_DRV(I915_GEM_WAIT, i915_gem_wait_ioctl, DRM_RENDER_ALLOW),
>>>>    	DRM_IOCTL_DEF_DRV(I915_GEM_CONTEXT_CREATE_EXT, i915_gem_context_create_ioctl, DRM_RENDER_ALLOW),
>>>>    	DRM_IOCTL_DEF_DRV(I915_GEM_CONTEXT_DESTROY, i915_gem_context_destroy_ioctl, DRM_RENDER_ALLOW),
>>>> -	DRM_IOCTL_DEF_DRV(I915_REG_READ, i915_reg_read_ioctl, DRM_RENDER_ALLOW),
>>>> +	DRM_IOCTL_DEF_DRV(I915_REG_READ, intel_uncore_reg_read_ioctl, DRM_RENDER_ALLOW),
>>>>    	DRM_IOCTL_DEF_DRV(I915_GET_RESET_STATS, i915_gem_context_reset_stats_ioctl, DRM_RENDER_ALLOW),
>>>>    	DRM_IOCTL_DEF_DRV(I915_GEM_USERPTR, i915_gem_userptr_ioctl, DRM_RENDER_ALLOW),
>>>>    	DRM_IOCTL_DEF_DRV(I915_GEM_CONTEXT_GETPARAM, i915_gem_context_getparam_ioctl, DRM_RENDER_ALLOW),
>>>> diff --git a/drivers/gpu/drm/i915/intel_uncore.c b/drivers/gpu/drm/i915/intel_uncore.c
>>>> index fc25ebf1a593..33f95bb2d3d5 100644
>>>> --- a/drivers/gpu/drm/i915/intel_uncore.c
>>>> +++ b/drivers/gpu/drm/i915/intel_uncore.c
>>>> @@ -2269,8 +2269,8 @@ static const struct reg_whitelist {
>>>>    	.size = 8
>>>>    } };
>>>>    
>>>> -int i915_reg_read_ioctl(struct drm_device *dev,
>>>> -			void *data, struct drm_file *file)
>>>> +int intel_uncore_reg_read_ioctl(struct drm_device *dev,
>>>> +				void *data, struct drm_file *file)
>>>>    {
>>>>    	struct drm_i915_private *i915 = to_i915(dev);
>>>>    	struct intel_uncore *uncore = &i915->uncore;
>>>> diff --git a/drivers/gpu/drm/i915/intel_uncore.h b/drivers/gpu/drm/i915/intel_uncore.h
>>>> index 3a87bbd906f8..697ac4586159 100644
>>>> --- a/drivers/gpu/drm/i915/intel_uncore.h
>>>> +++ b/drivers/gpu/drm/i915/intel_uncore.h
>>>> @@ -457,7 +457,7 @@ static inline int intel_uncore_write_and_verify(struct intel_uncore *uncore,
>>>>    #define raw_reg_write(base, reg, value) \
>>>>    	writel(value, base + i915_mmio_reg_offset(reg))
>>>>    
>>>> -int i915_reg_read_ioctl(struct drm_device *dev, void *data,
>>>> -			struct drm_file *file);
>>>> +int intel_uncore_reg_read_ioctl(struct drm_device *dev, void *data,
>>>> +				struct drm_file *file);
>>>>    
>>>>    #endif /* !__INTEL_UNCORE_H__ */
>>>>
>> 

-- 
Jani Nikula, Intel Open Source Graphics Center