[Intel-gfx] [PATCH 5/6] drm/i915/uc: Move uC debugfs to its own folder under GT

[Andi Shyti]

Hi Daniele,

> > On Thu, Feb 27, 2020 at 06:28:42PM -0800, Daniele Ceraolo Spurio wrote:
> > > uC is a component of the GT, so it makes sense for the uC debugfs files
> > > to be in the GT folder. A subfolder has been used to keep the same
> > > structure we have for the code.
> > 
> > Can we please document the interface changes. I see there are
> > some differences between the original and the new interfaces.
> > 
> 
> What differences are you referring to? there aren't supposed to be any,
> aside from the path change.

Have I seen it wrong or there are new files in this patch?
In any case, maybe we need to have the new structure.

> > > +#define DEFINE_UC_DEBUGFS_ATTRIBUTE(__name)				\
> > > +	static int __name ## _open(struct inode *inode, struct file *file) \
> > > +{									\
> > > +	return single_open(file, __name ## _show, inode->i_private);	\
> > > +}									\
> > > +static const struct file_operations __name ## _fops = {			\
> > > +	.owner = THIS_MODULE,						\
> > > +	.open = __name ## _open,					\
> > > +	.read = seq_read,						\
> > > +	.llseek = seq_lseek,						\
> > > +	.release = single_release,					\
> > > +}
> > 
> > Why do we need DEFINE_UC_DEBUGFS_ATTRIBUTE()?
> > 
> > DEFINE_GT_DEBUGFS_ATTRIBUTE() was meant to be common to all gt
> > debugfs. I there any reason we need a new one?
> > 
> 
> Just wanted to avoid including the other header just for this macro.

well that was supposed to be a library for all the gem/debugfs
files and avoid duplicated code, I don't see anything wrong with
including the file.

> > > +struct debugfs_uc_file {
> > > +	const char *name;
> > > +	const struct file_operations *fops;
> > > +};
> > > +
> > > +#define debugfs_uc_register_files(files__, root__, data__) \
> > > +do { \
> > > +	int i__ = 0; \
> > > +	for (i__ = 0; i__ < ARRAY_SIZE(files__); i__++) { \
> > > +		debugfs_create_file(files__[i__].name, \
> > > +				    0444, root__, data__, \
> > > +				    files__[i__].fops); \
> > > +	} \
> > > +} while (0)
> > 
> > You want to define your own debugfs_uc_register_files() instead
> > of using debugfs_gt_register_files() because you want "data__"
> > to be void, right?
> > 
> > I think we can achieve that by adding a wrapper in debugfs_gt.c,
> > perhaps we can do something like:
> > 
> > void __debugfs_gt_register_files(struct intel_gt *gt,
> >                                   struct dentry *root,
> >                                   const struct debugfs_gt_file *files,
> >                                   void *data,
> >                                   unsigned long count)
> > {
> >        ......
> > }
> > 
> > and
> > 
> > #define debugfs_gt_register_files(...) __debugfs_gt_register_files(...)
> > #define debugfs_uc_register_files(...) __debugfs_gt_register_files(...)
> > 
> > so that we can keep everything in a library. What do you think.
> > 
> 
> LGTM. Mind if I rename to:
> 
> intel_gt_debugfs_register(...)
> intel_uc_debugfs_register(...)
> 
> to avoid the debugfs_* prefix, as pointed out by Jani?

I have a patch for it, can you please hold a little, unless, of
course, yours is already ready.

Obvously, the naming you propose makes sense.

Andi