On Thu, Oct 07, 2021 at 07:13:25PM +0200, Thierry Reding wrote:

quoted

@@ -496,6 +506,8 @@ static void tegra_smmu_as_unprepare(struct tegra_smmu *smmu,
 	mutex_unlock(&smmu->lock);
 }
 
+static const struct file_operations tegra_smmu_debugfs_mappings_fops;

Could the implementation be moved up here to avoid the forward
declaration?

I thought that keeping all debugfs fops together would be preferable.
But yes, I will move it if you prefer no-additional forward declare.

quoted

+	seq_printf(s, "\nSWGROUP: %s\n", swgrp->name);
+	seq_printf(s, "as->id: %d\nas->attr: %c|%c|%s\nas->pd_dma: %pad\n", as->id,
+		   as->attr & SMMU_PD_READABLE ? 'R' : '-',
+		   as->attr & SMMU_PD_WRITABLE ? 'W' : '-',
+		   as->attr & SMMU_PD_NONSECURE ? "NS" : "S",
+		   &as->pd_dma);
+	seq_puts(s, "{\n");

Maybe this can be more compact by putting the name, ID, attributes and
base address onto a single line? Maybe also use "'-' : 'S'" for the
non-secure attribute to keep in line with what you've done for readable
and writable attributes.

Okay. Will change that.

Then again, this is going to be very verbose output anyway, so maybe it
isn't worth it.

Are you saying the whole debugfs thing or just attributes? Yet, for
either case, I don't think so, as mappings info would help for sure
from our past experience while the attributes are just one line...