drm/xe/pm: Toggle d3cold_allowed using vram_usages

Adding support to control d3cold by using vram_usages metric from
ttm resource manager.
When root port  is capable of d3cold but xe has disallowed d3cold
due to vram_usages above vram_d3ccold_threshol. It is required to
disable d3cold to avoid any resume failure because root port can
still transition to d3cold when all of pcie endpoints and
{upstream, virtual} switch ports will transition to d3hot.
Also cleaning up the TODO code comment.

v2:
- Modify d3cold.allowed in xe_pm_d3cold_allowed_toggle. [Riana]
- Cond changed (total_vram_used_mb < xe->d3cold.vram_threshold)
  according to doc comment.
v3:
- Added enum instead of true/false argument in
  d3cold_toggle(). [Rodrigo]
- Removed TODO comment. [Rodrigo]

Cc: Rodrigo Vivi <rodrigo.vivi@intel.com>
Signed-off-by: Anshuman Gupta <anshuman.gupta@intel.com>
Reviewed-by: Badal Nilawar <badal.nilawar@intel.com>
Acked-by: Rodrigo Vivi <rodrigo.vivi@intel.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20230718080703.239343-5-anshuman.gupta@intel.com
Signed-off-by: Rodrigo Vivi <rodrigo.vivi@intel.com>

1 files changed, 25 insertions, 0 deletions

diff --git a/drivers/gpu/drm/xe/xe_pm.c b/drivers/gpu/drm/xe/xe_pm.c
index 261c0ad57b63..21964e4d09f8 100644
--- a/drivers/gpu/drm/xe/xe_pm.c
+++ b/drivers/gpu/drm/xe/xe_pm.c
@@ -280,3 +280,28 @@ int xe_pm_set_vram_threshold(struct xe_device *xe, u32 threshold)
 
 	return 0;
 }
+
+void xe_pm_d3cold_allowed_toggle(struct xe_device *xe)
+{
+	struct ttm_resource_manager *man;
+	u32 total_vram_used_mb = 0;
+	u64 vram_used;
+	int i;
+
+	for (i = XE_PL_VRAM0; i <= XE_PL_VRAM1; ++i) {
+		man = ttm_manager_type(&xe->ttm, i);
+		if (man) {
+			vram_used = ttm_resource_manager_usage(man);
+			total_vram_used_mb += DIV_ROUND_UP_ULL(vram_used, 1024 * 1024);
+		}
+	}
+
+	mutex_lock(&xe->d3cold.lock);
+
+	if (total_vram_used_mb < xe->d3cold.vram_threshold)
+		xe->d3cold.allowed = true;
+	else
+		xe->d3cold.allowed = false;
+
+	mutex_unlock(&xe->d3cold.lock);
+}