drm/xe: Enable Coarse Power Gating

Enable power gating for all units and sub-pipes that
are disabled by default.

v2: change the init function name
    use symmetric calls for enable/disable pg
    re-pharase commit message (Rodrigo)
    modify the sub-pipe power gating condition

v3: set hysteresis value for render and media
    when GuC PC is disabled
    skip CPG for PVC (Vinay)

v4: rebase
Signed-off-by: Riana Tauro <riana.tauro@intel.com>
Reviewed-by: Rodrigo Vivi <rodrigo.vivi@intel.com> #v2
Reviewed-by: Vinay Belgaumkar <vinay.belgaumkar@intel.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20240524070916.143022-3-riana.tauro@intel.comSigned-off-by: Rodrigo Vivi <rodrigo.vivi@intel.com>

drivers/gpu/drm/xe/regs/xe_gt_regs.h

@@ -309,6 +309,8 @@
 #define   RC_CTL_RC6_ENABLE			REG_BIT(18)
 #define RC_STATE				XE_REG(0xa094)
 #define RC_IDLE_HYSTERSIS			XE_REG(0xa0ac)
+#define MEDIA_POWERGATE_IDLE_HYSTERESIS		XE_REG(0xa0c4)
+#define RENDER_POWERGATE_IDLE_HYSTERESIS	XE_REG(0xa0c8)
 
 #define PMINTRMSK				XE_REG(0xa168)
 #define   PMINTR_DISABLE_REDIRECT_TO_GUC	REG_BIT(31)
@@ -317,6 +319,8 @@
 #define FORCEWAKE_GT				XE_REG(0xa188)
 
 #define POWERGATE_ENABLE			XE_REG(0xa210)
+#define   RENDER_POWERGATE_ENABLE		REG_BIT(0)
+#define   MEDIA_POWERGATE_ENABLE		REG_BIT(1)
 #define   VDN_HCP_POWERGATE_ENABLE(n)		REG_BIT(3 + 2 * (n))
 #define   VDN_MFXVDENC_POWERGATE_ENABLE(n)	REG_BIT(4 + 2 * (n))
 

drivers/gpu/drm/xe/xe_gt.c

@@ -366,10 +366,6 @@ static int gt_fw_domain_init(struct xe_gt *gt)
 			xe_lmtt_init(&gt_to_tile(gt)->sriov.pf.lmtt);
 	}
 
-	err = xe_gt_idle_sysfs_init(&gt->gtidle);
-	if (err)
-		goto err_force_wake;
-
 	/* Enable per hw engine IRQs */
 	xe_irq_enable_hwe(gt);
 
@@ -554,6 +550,10 @@ int xe_gt_init(struct xe_gt *gt)
 	if (err)
 		return err;
 
+	err = xe_gt_idle_init(&gt->gtidle);
+	if (err)
+		return err;
+
 	err = xe_gt_freq_init(gt);
 	if (err)
 		return err;
@@ -760,6 +760,8 @@ int xe_gt_suspend(struct xe_gt *gt)
 	if (err)
 		goto err_force_wake;
 
+	xe_gt_idle_disable_pg(gt);
+
 	XE_WARN_ON(xe_force_wake_put(gt_to_fw(gt), XE_FORCEWAKE_ALL));
 	xe_gt_dbg(gt, "suspended\n");
 
@@ -786,6 +788,8 @@ int xe_gt_resume(struct xe_gt *gt)
 	if (err)
 		goto err_force_wake;
 
+	xe_gt_idle_enable_pg(gt);
+
 	XE_WARN_ON(xe_force_wake_put(gt_to_fw(gt), XE_FORCEWAKE_ALL));
 	xe_gt_dbg(gt, "resumed\n");
 

drivers/gpu/drm/xe/xe_gt_idle.c

@@ -12,6 +12,7 @@
 #include "xe_gt_sysfs.h"
 #include "xe_guc_pc.h"
 #include "regs/xe_gt_regs.h"
+#include "xe_macros.h"
 #include "xe_mmio.h"
 #include "xe_pm.h"
 
@@ -93,6 +94,50 @@ static u64 get_residency_ms(struct xe_gt_idle *gtidle, u64 cur_residency)
 	return cur_residency;
 }
 
+void xe_gt_idle_enable_pg(struct xe_gt *gt)
+{
+	struct xe_device *xe = gt_to_xe(gt);
+	u32 pg_enable;
+	int i, j;
+
+	/* Disable CPG for PVC */
+	if (xe->info.platform == XE_PVC)
+		return;
+
+	xe_device_assert_mem_access(gt_to_xe(gt));
+
+	pg_enable = RENDER_POWERGATE_ENABLE | MEDIA_POWERGATE_ENABLE;
+
+	for (i = XE_HW_ENGINE_VCS0, j = 0; i <= XE_HW_ENGINE_VCS7; ++i, ++j) {
+		if ((gt->info.engine_mask & BIT(i)))
+			pg_enable |= (VDN_HCP_POWERGATE_ENABLE(j) |
+				      VDN_MFXVDENC_POWERGATE_ENABLE(j));
+	}
+
+	XE_WARN_ON(xe_force_wake_get(gt_to_fw(gt), XE_FW_GT));
+	if (xe->info.skip_guc_pc) {
+		/*
+		 * GuC sets the hysteresis value when GuC PC is enabled
+		 * else set it to 25 (25 * 1.28us)
+		 */
+		xe_mmio_write32(gt, MEDIA_POWERGATE_IDLE_HYSTERESIS, 25);
+		xe_mmio_write32(gt, RENDER_POWERGATE_IDLE_HYSTERESIS, 25);
+	}
+
+	xe_mmio_write32(gt, POWERGATE_ENABLE, pg_enable);
+	XE_WARN_ON(xe_force_wake_put(gt_to_fw(gt), XE_FW_GT));
+}
+
+void xe_gt_idle_disable_pg(struct xe_gt *gt)
+{
+	xe_device_assert_mem_access(gt_to_xe(gt));
+	XE_WARN_ON(xe_force_wake_get(gt_to_fw(gt), XE_FW_GT));
+
+	xe_mmio_write32(gt, POWERGATE_ENABLE, 0);
+
+	XE_WARN_ON(xe_force_wake_put(gt_to_fw(gt), XE_FW_GT));
+}
+
 static ssize_t name_show(struct device *dev,
 			 struct device_attribute *attr, char *buff)
 {
@@ -145,15 +190,18 @@ static const struct attribute *gt_idle_attrs[] = {
 	NULL,
 };
 
-static void gt_idle_sysfs_fini(void *arg)
+static void gt_idle_fini(void *arg)
 {
 	struct kobject *kobj = arg;
+	struct xe_gt *gt = kobj_to_gt(kobj->parent);
+
+	xe_gt_idle_disable_pg(gt);
 
 	sysfs_remove_files(kobj, gt_idle_attrs);
 	kobject_put(kobj);
 }
 
-int xe_gt_idle_sysfs_init(struct xe_gt_idle *gtidle)
+int xe_gt_idle_init(struct xe_gt_idle *gtidle)
 {
 	struct xe_gt *gt = gtidle_to_gt(gtidle);
 	struct xe_device *xe = gt_to_xe(gt);
@@ -182,7 +230,9 @@ int xe_gt_idle_sysfs_init(struct xe_gt_idle *gtidle)
 		return err;
 	}
 
-	return devm_add_action_or_reset(xe->drm.dev, gt_idle_sysfs_fini, kobj);
+	xe_gt_idle_enable_pg(gt);
+
+	return devm_add_action_or_reset(xe->drm.dev, gt_idle_fini, kobj);
 }
 
 void xe_gt_idle_enable_c6(struct xe_gt *gt)
@@ -202,7 +252,6 @@ void xe_gt_idle_disable_c6(struct xe_gt *gt)
 	xe_device_assert_mem_access(gt_to_xe(gt));
 	xe_force_wake_assert_held(gt_to_fw(gt), XE_FORCEWAKE_ALL);
 
-	xe_mmio_write32(gt, POWERGATE_ENABLE, 0);
 	xe_mmio_write32(gt, RC_CONTROL, 0);
 	xe_mmio_write32(gt, RC_STATE, 0);
 }

drivers/gpu/drm/xe/xe_gt_idle.h

@@ -10,8 +10,10 @@
 
 struct xe_gt;
 
-int xe_gt_idle_sysfs_init(struct xe_gt_idle *gtidle);
+int xe_gt_idle_init(struct xe_gt_idle *gtidle);
 void xe_gt_idle_enable_c6(struct xe_gt *gt);
 void xe_gt_idle_disable_c6(struct xe_gt *gt);
+void xe_gt_idle_enable_pg(struct xe_gt *gt);
+void xe_gt_idle_disable_pg(struct xe_gt *gt);
 
 #endif /* _XE_GT_IDLE_H_ */