[PATCH 1/2] drm/i915/gt: Create gt/gtN/.defaults/ for per gt sysfs defaults

[Ashutosh Dixit]

Create a gt/gtN/.defaults/ directory (similar to
engine/<engine-name>/.defaults/) to expose default parameter values for
each gt in sysfs. This allows userspace to restore default parameter values
after they have changed. The empty 'struct gt_defaults' will be populated
by subsequent patches.

v2: Changed 'struct intel_rps_defaults rps_defaults' to
    'struct gt_defaults defaults' (Andi)

Cc: Tvrtko Ursulin <tvrtko.ursu...@linux.intel.com>
Cc: Andi Shyti <andi.sh...@linux.intel.com>
Signed-off-by: Ashutosh Dixit <ashutosh.di...@intel.com>
Reviewed-by: Rodrigo Vivi <rodrigo.v...@intel.com>
---
 drivers/gpu/drm/i915/gt/intel_gt_sysfs.c | 5 +++++
 drivers/gpu/drm/i915/gt/intel_gt_types.h | 7 +++++++
 2 files changed, 12 insertions(+)

diff --git a/drivers/gpu/drm/i915/gt/intel_gt_sysfs.c 
b/drivers/gpu/drm/i915/gt/intel_gt_sysfs.c
index 9e4ebf53379b..6447c0376dbd 100644
--- a/drivers/gpu/drm/i915/gt/intel_gt_sysfs.c
+++ b/drivers/gpu/drm/i915/gt/intel_gt_sysfs.c
@@ -101,6 +101,10 @@ void intel_gt_sysfs_register(struct intel_gt *gt)
                                 gt->i915->sysfs_gt, "gt%d", gt->info.id))
                goto exit_fail;
 
+       gt->sysfs_defaults = kobject_create_and_add(".defaults", &gt->sysfs_gt);
+       if (!gt->sysfs_defaults)
+               goto exit_fail;
+
        intel_gt_sysfs_pm_init(gt, &gt->sysfs_gt);
 
        return;
@@ -113,5 +117,6 @@ void intel_gt_sysfs_register(struct intel_gt *gt)
 
 void intel_gt_sysfs_unregister(struct intel_gt *gt)
 {
+       kobject_put(gt->sysfs_defaults);
        kobject_put(&gt->sysfs_gt);
 }
diff --git a/drivers/gpu/drm/i915/gt/intel_gt_types.h 
b/drivers/gpu/drm/i915/gt/intel_gt_types.h
index df708802889d..92839b9adb12 100644
--- a/drivers/gpu/drm/i915/gt/intel_gt_types.h
+++ b/drivers/gpu/drm/i915/gt/intel_gt_types.h
@@ -75,6 +75,9 @@ enum intel_submission_method {
        INTEL_SUBMISSION_GUC,
 };
 
+struct gt_defaults {
+};
+
 struct intel_gt {
        struct drm_i915_private *i915;
        struct intel_uncore *uncore;
@@ -235,6 +238,10 @@ struct intel_gt {
 
        /* gt/gtN sysfs */
        struct kobject sysfs_gt;
+
+       /* sysfs defaults per gt */
+       struct gt_defaults defaults;
+       struct kobject *sysfs_defaults;
 };
 
 enum intel_gt_scratch_field {
-- 
2.34.1