[Intel-gfx] [PATCH 1/2] drm/i915: Split gt cache flushing and gt idling functions

[Andi Shyti]

In preparation for multi-gt cache flushing debugfs interface,
split the cache dropping function and gt idling.

Based on a patch by Tvrtko.

Signed-off-by: Andi Shyti <andi.sh...@linux.intel.com>
Cc: Tvrtko Ursulin <tvrtko.ursu...@intel.com>
---
 drivers/gpu/drm/i915/i915_debugfs.c | 32 +++++++++++++++++++++--------
 1 file changed, 24 insertions(+), 8 deletions(-)

diff --git a/drivers/gpu/drm/i915/i915_debugfs.c 
b/drivers/gpu/drm/i915/i915_debugfs.c
index 7a90a2e32c9f1..3dfe8a8b7cdfe 100644
--- a/drivers/gpu/drm/i915/i915_debugfs.c
+++ b/drivers/gpu/drm/i915/i915_debugfs.c
@@ -703,11 +703,25 @@ i915_drop_caches_get(void *data, u64 *val)
        return 0;
 }
 
+static int gt_idle(struct intel_gt *gt, u64 val)
+{
+       if (val & (DROP_RETIRE | DROP_IDLE))
+               intel_gt_retire_requests(gt);
+
+       if (val & DROP_IDLE) {
+               int ret;
+
+               ret = intel_gt_pm_wait_for_idle(gt);
+               if (ret)
+                       return ret;
+       }
+
+       return 0;
+}
+
 static int
 gt_drop_caches(struct intel_gt *gt, u64 val)
 {
-       int ret;
-
        if (val & DROP_RESET_ACTIVE &&
            wait_for(intel_engines_are_idle(gt), 200))
                intel_gt_set_wedged(gt);
@@ -716,13 +730,9 @@ gt_drop_caches(struct intel_gt *gt, u64 val)
                intel_gt_retire_requests(gt);
 
        if (val & (DROP_IDLE | DROP_ACTIVE)) {
-               ret = intel_gt_wait_for_idle(gt, MAX_SCHEDULE_TIMEOUT);
-               if (ret)
-                       return ret;
-       }
+               int ret;
 
-       if (val & DROP_IDLE) {
-               ret = intel_gt_pm_wait_for_idle(gt);
+               ret = intel_gt_wait_for_idle(gt, MAX_SCHEDULE_TIMEOUT);
                if (ret)
                        return ret;
        }
@@ -746,10 +756,16 @@ i915_drop_caches_set(void *data, u64 val)
        drm_dbg(&i915->drm, "Dropping caches: 0x%08llx [0x%08llx]\n",
                val, val & DROP_ALL);
 
+       /* Flush all the active requests across both GT ... */
        ret = gt_drop_caches(to_gt(i915), val);
        if (ret)
                return ret;
 
+       /* ... then wait for idle as there may be cross-gt wakerefs. */
+       ret = gt_idle(to_gt(i915), val);
+       if (ret)
+               return ret;
+
        fs_reclaim_acquire(GFP_KERNEL);
        flags = memalloc_noreclaim_save();
        if (val & DROP_BOUND)
-- 
2.40.1