Merge tag 'topic/mst-bw-check-fixes-for-airlied-2020-03-12-2' of git://anongit.freedesktop.org/drm/drm-misc into drm-fixes

UAPI Changes: None

Cross-subsystem Changes: None

Core Changes: Fixed regressions introduced by commit cd82d82cbc04
("drm/dp_mst: Add branch bandwidth validation to MST atomic check"),
which would cause us to:

* Calculate the available bandwidth on an MST topology incorrectly, and
  as a result reject most display configurations that would try to enable
  more then one sink on a topology
* Occasionally expose MST connectors to userspace before finishing
  probing their PBN capabilities, resulting in us rejecting display
  configurations because we assumed briefly that no bandwidth was
  available

Driver Changes: None

Signed-off-by: Dave Airlie <airlied@redhat.com>
From: Lyude Paul <lyude@redhat.com>
Link: https://patchwork.freedesktop.org/patch/msgid/bf16ee577567beed91c86b7d9cda3ec2e8c50a71.camel@redhat.com
diff --git a/drivers/gpu/drm/amd/amdgpu/soc15.c b/drivers/gpu/drm/amd/amdgpu/soc15.c
index 2b488df..d8945c3 100644
--- a/drivers/gpu/drm/amd/amdgpu/soc15.c
+++ b/drivers/gpu/drm/amd/amdgpu/soc15.c
@@ -89,6 +89,13 @@
 #define HDP_MEM_POWER_CTRL__RC_MEM_POWER_CTRL_EN_MASK	0x00010000L
 #define HDP_MEM_POWER_CTRL__RC_MEM_POWER_LS_EN_MASK		0x00020000L
 #define mmHDP_MEM_POWER_CTRL_BASE_IDX	0
+
+/* for Vega20/arcturus regiter offset change */
+#define	mmROM_INDEX_VG20				0x00e4
+#define	mmROM_INDEX_VG20_BASE_IDX			0
+#define	mmROM_DATA_VG20					0x00e5
+#define	mmROM_DATA_VG20_BASE_IDX			0
+
 /*
  * Indirect registers accessor
  */
@@ -309,6 +316,8 @@
 {
 	u32 *dw_ptr;
 	u32 i, length_dw;
+	uint32_t rom_index_offset;
+	uint32_t rom_data_offset;
 
 	if (bios == NULL)
 		return false;
@@ -321,11 +330,23 @@
 	dw_ptr = (u32 *)bios;
 	length_dw = ALIGN(length_bytes, 4) / 4;
 
+	switch (adev->asic_type) {
+	case CHIP_VEGA20:
+	case CHIP_ARCTURUS:
+		rom_index_offset = SOC15_REG_OFFSET(SMUIO, 0, mmROM_INDEX_VG20);
+		rom_data_offset = SOC15_REG_OFFSET(SMUIO, 0, mmROM_DATA_VG20);
+		break;
+	default:
+		rom_index_offset = SOC15_REG_OFFSET(SMUIO, 0, mmROM_INDEX);
+		rom_data_offset = SOC15_REG_OFFSET(SMUIO, 0, mmROM_DATA);
+		break;
+	}
+
 	/* set rom index to 0 */
-	WREG32(SOC15_REG_OFFSET(SMUIO, 0, mmROM_INDEX), 0);
+	WREG32(rom_index_offset, 0);
 	/* read out the rom data */
 	for (i = 0; i < length_dw; i++)
-		dw_ptr[i] = RREG32(SOC15_REG_OFFSET(SMUIO, 0, mmROM_DATA));
+		dw_ptr[i] = RREG32(rom_data_offset);
 
 	return true;
 }
diff --git a/drivers/gpu/drm/amd/display/dc/dcn20/dcn20_resource.c b/drivers/gpu/drm/amd/display/dc/dcn20/dcn20_resource.c
index 85f90f3..e310d67 100644
--- a/drivers/gpu/drm/amd/display/dc/dcn20/dcn20_resource.c
+++ b/drivers/gpu/drm/amd/display/dc/dcn20/dcn20_resource.c
@@ -335,6 +335,117 @@
 	.use_urgent_burst_bw = 0
 };
 
+struct _vcs_dpi_soc_bounding_box_st dcn2_0_nv14_soc = {
+	.clock_limits = {
+			{
+				.state = 0,
+				.dcfclk_mhz = 560.0,
+				.fabricclk_mhz = 560.0,
+				.dispclk_mhz = 513.0,
+				.dppclk_mhz = 513.0,
+				.phyclk_mhz = 540.0,
+				.socclk_mhz = 560.0,
+				.dscclk_mhz = 171.0,
+				.dram_speed_mts = 8960.0,
+			},
+			{
+				.state = 1,
+				.dcfclk_mhz = 694.0,
+				.fabricclk_mhz = 694.0,
+				.dispclk_mhz = 642.0,
+				.dppclk_mhz = 642.0,
+				.phyclk_mhz = 600.0,
+				.socclk_mhz = 694.0,
+				.dscclk_mhz = 214.0,
+				.dram_speed_mts = 11104.0,
+			},
+			{
+				.state = 2,
+				.dcfclk_mhz = 875.0,
+				.fabricclk_mhz = 875.0,
+				.dispclk_mhz = 734.0,
+				.dppclk_mhz = 734.0,
+				.phyclk_mhz = 810.0,
+				.socclk_mhz = 875.0,
+				.dscclk_mhz = 245.0,
+				.dram_speed_mts = 14000.0,
+			},
+			{
+				.state = 3,
+				.dcfclk_mhz = 1000.0,
+				.fabricclk_mhz = 1000.0,
+				.dispclk_mhz = 1100.0,
+				.dppclk_mhz = 1100.0,
+				.phyclk_mhz = 810.0,
+				.socclk_mhz = 1000.0,
+				.dscclk_mhz = 367.0,
+				.dram_speed_mts = 16000.0,
+			},
+			{
+				.state = 4,
+				.dcfclk_mhz = 1200.0,
+				.fabricclk_mhz = 1200.0,
+				.dispclk_mhz = 1284.0,
+				.dppclk_mhz = 1284.0,
+				.phyclk_mhz = 810.0,
+				.socclk_mhz = 1200.0,
+				.dscclk_mhz = 428.0,
+				.dram_speed_mts = 16000.0,
+			},
+			/*Extra state, no dispclk ramping*/
+			{
+				.state = 5,
+				.dcfclk_mhz = 1200.0,
+				.fabricclk_mhz = 1200.0,
+				.dispclk_mhz = 1284.0,
+				.dppclk_mhz = 1284.0,
+				.phyclk_mhz = 810.0,
+				.socclk_mhz = 1200.0,
+				.dscclk_mhz = 428.0,
+				.dram_speed_mts = 16000.0,
+			},
+		},
+	.num_states = 5,
+	.sr_exit_time_us = 8.6,
+	.sr_enter_plus_exit_time_us = 10.9,
+	.urgent_latency_us = 4.0,
+	.urgent_latency_pixel_data_only_us = 4.0,
+	.urgent_latency_pixel_mixed_with_vm_data_us = 4.0,
+	.urgent_latency_vm_data_only_us = 4.0,
+	.urgent_out_of_order_return_per_channel_pixel_only_bytes = 4096,
+	.urgent_out_of_order_return_per_channel_pixel_and_vm_bytes = 4096,
+	.urgent_out_of_order_return_per_channel_vm_only_bytes = 4096,
+	.pct_ideal_dram_sdp_bw_after_urgent_pixel_only = 40.0,
+	.pct_ideal_dram_sdp_bw_after_urgent_pixel_and_vm = 40.0,
+	.pct_ideal_dram_sdp_bw_after_urgent_vm_only = 40.0,
+	.max_avg_sdp_bw_use_normal_percent = 40.0,
+	.max_avg_dram_bw_use_normal_percent = 40.0,
+	.writeback_latency_us = 12.0,
+	.ideal_dram_bw_after_urgent_percent = 40.0,
+	.max_request_size_bytes = 256,
+	.dram_channel_width_bytes = 2,
+	.fabric_datapath_to_dcn_data_return_bytes = 64,
+	.dcn_downspread_percent = 0.5,
+	.downspread_percent = 0.38,
+	.dram_page_open_time_ns = 50.0,
+	.dram_rw_turnaround_time_ns = 17.5,
+	.dram_return_buffer_per_channel_bytes = 8192,
+	.round_trip_ping_latency_dcfclk_cycles = 131,
+	.urgent_out_of_order_return_per_channel_bytes = 256,
+	.channel_interleave_bytes = 256,
+	.num_banks = 8,
+	.num_chans = 8,
+	.vmm_page_size_bytes = 4096,
+	.dram_clock_change_latency_us = 404.0,
+	.dummy_pstate_latency_us = 5.0,
+	.writeback_dram_clock_change_latency_us = 23.0,
+	.return_bus_width_bytes = 64,
+	.dispclk_dppclk_vco_speed_mhz = 3850,
+	.xfc_bus_transport_time_us = 20,
+	.xfc_xbuf_latency_tolerance_us = 4,
+	.use_urgent_burst_bw = 0
+};
+
 struct _vcs_dpi_soc_bounding_box_st dcn2_0_nv12_soc = { 0 };
 
 #ifndef mmDP0_DP_DPHY_INTERNAL_CTRL
@@ -3291,6 +3402,9 @@
 static struct _vcs_dpi_soc_bounding_box_st *get_asic_rev_soc_bb(
 	uint32_t hw_internal_rev)
 {
+	if (ASICREV_IS_NAVI14_M(hw_internal_rev))
+		return &dcn2_0_nv14_soc;
+
 	if (ASICREV_IS_NAVI12_P(hw_internal_rev))
 		return &dcn2_0_nv12_soc;
 
diff --git a/drivers/gpu/drm/amd/powerplay/amdgpu_smu.c b/drivers/gpu/drm/amd/powerplay/amdgpu_smu.c
index ad8e9b5..96e81c7 100644
--- a/drivers/gpu/drm/amd/powerplay/amdgpu_smu.c
+++ b/drivers/gpu/drm/amd/powerplay/amdgpu_smu.c
@@ -2006,8 +2006,11 @@
 			smu_feature_is_enabled(smu, SMU_FEATURE_DPM_DCEFCLK_BIT) &&
 			smu_feature_is_enabled(smu, SMU_FEATURE_DPM_SOCCLK_BIT)) {
 		smu_set_watermarks_table(smu, table, clock_ranges);
-		smu->watermarks_bitmap |= WATERMARKS_EXIST;
-		smu->watermarks_bitmap &= ~WATERMARKS_LOADED;
+
+		if (!(smu->watermarks_bitmap & WATERMARKS_EXIST)) {
+			smu->watermarks_bitmap |= WATERMARKS_EXIST;
+			smu->watermarks_bitmap &= ~WATERMARKS_LOADED;
+		}
 	}
 
 	mutex_unlock(&smu->mutex);
diff --git a/drivers/gpu/drm/amd/powerplay/navi10_ppt.c b/drivers/gpu/drm/amd/powerplay/navi10_ppt.c
index 0d73a49..aed4d6e 100644
--- a/drivers/gpu/drm/amd/powerplay/navi10_ppt.c
+++ b/drivers/gpu/drm/amd/powerplay/navi10_ppt.c
@@ -1063,15 +1063,6 @@
 	int ret = 0;
 
 	if ((smu->watermarks_bitmap & WATERMARKS_EXIST) &&
-	    !(smu->watermarks_bitmap & WATERMARKS_LOADED)) {
-		ret = smu_write_watermarks_table(smu);
-		if (ret)
-			return ret;
-
-		smu->watermarks_bitmap |= WATERMARKS_LOADED;
-	}
-
-	if ((smu->watermarks_bitmap & WATERMARKS_EXIST) &&
 	    smu_feature_is_supported(smu, SMU_FEATURE_DPM_DCEFCLK_BIT) &&
 	    smu_feature_is_supported(smu, SMU_FEATURE_DPM_SOCCLK_BIT)) {
 		ret = smu_send_smc_msg_with_param(smu, SMU_MSG_NumOfDisplays,
@@ -1493,6 +1484,7 @@
 				       *clock_ranges)
 {
 	int i;
+	int ret = 0;
 	Watermarks_t *table = watermarks;
 
 	if (!table || !clock_ranges)
@@ -1544,6 +1536,18 @@
 				clock_ranges->wm_mcif_clocks_ranges[i].wm_set_id;
 	}
 
+	smu->watermarks_bitmap |= WATERMARKS_EXIST;
+
+	/* pass data to smu controller */
+	if (!(smu->watermarks_bitmap & WATERMARKS_LOADED)) {
+		ret = smu_write_watermarks_table(smu);
+		if (ret) {
+			pr_err("Failed to update WMTABLE!");
+			return ret;
+		}
+		smu->watermarks_bitmap |= WATERMARKS_LOADED;
+	}
+
 	return 0;
 }
 
diff --git a/drivers/gpu/drm/amd/powerplay/renoir_ppt.c b/drivers/gpu/drm/amd/powerplay/renoir_ppt.c
index 568c041..3ad0f4a 100644
--- a/drivers/gpu/drm/amd/powerplay/renoir_ppt.c
+++ b/drivers/gpu/drm/amd/powerplay/renoir_ppt.c
@@ -806,9 +806,10 @@
 				clock_ranges->wm_mcif_clocks_ranges[i].wm_set_id;
 	}
 
+	smu->watermarks_bitmap |= WATERMARKS_EXIST;
+
 	/* pass data to smu controller */
-	if ((smu->watermarks_bitmap & WATERMARKS_EXIST) &&
-			!(smu->watermarks_bitmap & WATERMARKS_LOADED)) {
+	if (!(smu->watermarks_bitmap & WATERMARKS_LOADED)) {
 		ret = smu_write_watermarks_table(smu);
 		if (ret) {
 			pr_err("Failed to update WMTABLE!");
diff --git a/drivers/gpu/drm/i915/gem/i915_gem_execbuffer.c b/drivers/gpu/drm/i915/gem/i915_gem_execbuffer.c
index 60c984e..7643a30 100644
--- a/drivers/gpu/drm/i915/gem/i915_gem_execbuffer.c
+++ b/drivers/gpu/drm/i915/gem/i915_gem_execbuffer.c
@@ -423,7 +423,8 @@
 	if (unlikely(entry->flags & eb->invalid_flags))
 		return -EINVAL;
 
-	if (unlikely(entry->alignment && !is_power_of_2(entry->alignment)))
+	if (unlikely(entry->alignment &&
+		     !is_power_of_2_u64(entry->alignment)))
 		return -EINVAL;
 
 	/*
diff --git a/drivers/gpu/drm/i915/gt/intel_lrc.c b/drivers/gpu/drm/i915/gt/intel_lrc.c
index fe8a59a..940e7f7 100644
--- a/drivers/gpu/drm/i915/gt/intel_lrc.c
+++ b/drivers/gpu/drm/i915/gt/intel_lrc.c
@@ -1679,11 +1679,9 @@
 	if (!intel_engine_has_timeslices(engine))
 		return false;
 
-	if (list_is_last(&rq->sched.link, &engine->active.requests))
-		return false;
-
-	hint = max(rq_prio(list_next_entry(rq, sched.link)),
-		   engine->execlists.queue_priority_hint);
+	hint = engine->execlists.queue_priority_hint;
+	if (!list_is_last(&rq->sched.link, &engine->active.requests))
+		hint = max(hint, rq_prio(list_next_entry(rq, sched.link)));
 
 	return hint >= effective_prio(rq);
 }
@@ -1725,6 +1723,18 @@
 	set_timer_ms(&engine->execlists.timer, active_timeslice(engine));
 }
 
+static void start_timeslice(struct intel_engine_cs *engine)
+{
+	struct intel_engine_execlists *execlists = &engine->execlists;
+
+	execlists->switch_priority_hint = execlists->queue_priority_hint;
+
+	if (timer_pending(&execlists->timer))
+		return;
+
+	set_timer_ms(&execlists->timer, timeslice(engine));
+}
+
 static void record_preemption(struct intel_engine_execlists *execlists)
 {
 	(void)I915_SELFTEST_ONLY(execlists->preempt_hang.count++);
@@ -1888,11 +1898,7 @@
 				 * Even if ELSP[1] is occupied and not worthy
 				 * of timeslices, our queue might be.
 				 */
-				if (!execlists->timer.expires &&
-				    need_timeslice(engine, last))
-					set_timer_ms(&execlists->timer,
-						     timeslice(engine));
-
+				start_timeslice(engine);
 				return;
 			}
 		}
@@ -1927,7 +1933,8 @@
 
 			if (last && !can_merge_rq(last, rq)) {
 				spin_unlock(&ve->base.active.lock);
-				return; /* leave this for another */
+				start_timeslice(engine);
+				return; /* leave this for another sibling */
 			}
 
 			ENGINE_TRACE(engine,
diff --git a/drivers/gpu/drm/i915/gt/intel_timeline.c b/drivers/gpu/drm/i915/gt/intel_timeline.c
index 8771652..d8d9f11 100644
--- a/drivers/gpu/drm/i915/gt/intel_timeline.c
+++ b/drivers/gpu/drm/i915/gt/intel_timeline.c
@@ -192,11 +192,15 @@
 
 static void cacheline_free(struct intel_timeline_cacheline *cl)
 {
+	if (!i915_active_acquire_if_busy(&cl->active)) {
+		__idle_cacheline_free(cl);
+		return;
+	}
+
 	GEM_BUG_ON(ptr_test_bit(cl->vaddr, CACHELINE_FREE));
 	cl->vaddr = ptr_set_bit(cl->vaddr, CACHELINE_FREE);
 
-	if (i915_active_is_idle(&cl->active))
-		__idle_cacheline_free(cl);
+	i915_active_release(&cl->active);
 }
 
 int intel_timeline_init(struct intel_timeline *timeline,
diff --git a/drivers/gpu/drm/i915/gvt/display.c b/drivers/gpu/drm/i915/gvt/display.c
index e1c313d..a62bdf9 100644
--- a/drivers/gpu/drm/i915/gvt/display.c
+++ b/drivers/gpu/drm/i915/gvt/display.c
@@ -457,7 +457,8 @@
 	struct drm_i915_private *dev_priv = vgpu->gvt->dev_priv;
 
 	/* TODO: add more platforms support */
-	if (IS_SKYLAKE(dev_priv) || IS_KABYLAKE(dev_priv)) {
+	if (IS_SKYLAKE(dev_priv) || IS_KABYLAKE(dev_priv) ||
+		IS_COFFEELAKE(dev_priv)) {
 		if (connected) {
 			vgpu_vreg_t(vgpu, SFUSE_STRAP) |=
 				SFUSE_STRAP_DDID_DETECTED;
diff --git a/drivers/gpu/drm/i915/gvt/opregion.c b/drivers/gpu/drm/i915/gvt/opregion.c
index 867e762..33569b9 100644
--- a/drivers/gpu/drm/i915/gvt/opregion.c
+++ b/drivers/gpu/drm/i915/gvt/opregion.c
@@ -147,15 +147,14 @@
 	/* there's features depending on version! */
 	v->header.version = 155;
 	v->header.header_size = sizeof(v->header);
-	v->header.vbt_size = sizeof(struct vbt) - sizeof(v->header);
+	v->header.vbt_size = sizeof(struct vbt);
 	v->header.bdb_offset = offsetof(struct vbt, bdb_header);
 
 	strcpy(&v->bdb_header.signature[0], "BIOS_DATA_BLOCK");
 	v->bdb_header.version = 186; /* child_dev_size = 33 */
 	v->bdb_header.header_size = sizeof(v->bdb_header);
 
-	v->bdb_header.bdb_size = sizeof(struct vbt) - sizeof(struct vbt_header)
-		- sizeof(struct bdb_header);
+	v->bdb_header.bdb_size = sizeof(struct vbt) - sizeof(struct vbt_header);
 
 	/* general features */
 	v->general_features_header.id = BDB_GENERAL_FEATURES;
diff --git a/drivers/gpu/drm/i915/gvt/vgpu.c b/drivers/gpu/drm/i915/gvt/vgpu.c
index 487af6e..345c2aa 100644
--- a/drivers/gpu/drm/i915/gvt/vgpu.c
+++ b/drivers/gpu/drm/i915/gvt/vgpu.c
@@ -272,10 +272,17 @@
 {
 	struct intel_gvt *gvt = vgpu->gvt;
 
-	mutex_lock(&vgpu->vgpu_lock);
-
 	WARN(vgpu->active, "vGPU is still active!\n");
 
+	/*
+	 * remove idr first so later clean can judge if need to stop
+	 * service if no active vgpu.
+	 */
+	mutex_lock(&gvt->lock);
+	idr_remove(&gvt->vgpu_idr, vgpu->id);
+	mutex_unlock(&gvt->lock);
+
+	mutex_lock(&vgpu->vgpu_lock);
 	intel_gvt_debugfs_remove_vgpu(vgpu);
 	intel_vgpu_clean_sched_policy(vgpu);
 	intel_vgpu_clean_submission(vgpu);
@@ -290,7 +297,6 @@
 	mutex_unlock(&vgpu->vgpu_lock);
 
 	mutex_lock(&gvt->lock);
-	idr_remove(&gvt->vgpu_idr, vgpu->id);
 	if (idr_is_empty(&gvt->vgpu_idr))
 		intel_gvt_clean_irq(gvt);
 	intel_gvt_update_vgpu_types(gvt);
diff --git a/drivers/gpu/drm/i915/i915_request.c b/drivers/gpu/drm/i915/i915_request.c
index dcaa85a..a18b2a2 100644
--- a/drivers/gpu/drm/i915/i915_request.c
+++ b/drivers/gpu/drm/i915/i915_request.c
@@ -527,19 +527,31 @@
 	return NOTIFY_DONE;
 }
 
+static void irq_semaphore_cb(struct irq_work *wrk)
+{
+	struct i915_request *rq =
+		container_of(wrk, typeof(*rq), semaphore_work);
+
+	i915_schedule_bump_priority(rq, I915_PRIORITY_NOSEMAPHORE);
+	i915_request_put(rq);
+}
+
 static int __i915_sw_fence_call
 semaphore_notify(struct i915_sw_fence *fence, enum i915_sw_fence_notify state)
 {
-	struct i915_request *request =
-		container_of(fence, typeof(*request), semaphore);
+	struct i915_request *rq = container_of(fence, typeof(*rq), semaphore);
 
 	switch (state) {
 	case FENCE_COMPLETE:
-		i915_schedule_bump_priority(request, I915_PRIORITY_NOSEMAPHORE);
+		if (!(READ_ONCE(rq->sched.attr.priority) & I915_PRIORITY_NOSEMAPHORE)) {
+			i915_request_get(rq);
+			init_irq_work(&rq->semaphore_work, irq_semaphore_cb);
+			irq_work_queue(&rq->semaphore_work);
+		}
 		break;
 
 	case FENCE_FREE:
-		i915_request_put(request);
+		i915_request_put(rq);
 		break;
 	}
 
@@ -776,8 +788,8 @@
 	struct dma_fence *fence;
 	int err;
 
-	GEM_BUG_ON(i915_request_timeline(rq) ==
-		   rcu_access_pointer(signal->timeline));
+	if (i915_request_timeline(rq) == rcu_access_pointer(signal->timeline))
+		return 0;
 
 	if (i915_request_started(signal))
 		return 0;
@@ -821,7 +833,7 @@
 		return 0;
 
 	err = 0;
-	if (intel_timeline_sync_is_later(i915_request_timeline(rq), fence))
+	if (!intel_timeline_sync_is_later(i915_request_timeline(rq), fence))
 		err = i915_sw_fence_await_dma_fence(&rq->submit,
 						    fence, 0,
 						    I915_FENCE_GFP);
@@ -1318,9 +1330,9 @@
 	 * decide whether to preempt the entire chain so that it is ready to
 	 * run at the earliest possible convenience.
 	 */
-	i915_sw_fence_commit(&rq->semaphore);
 	if (attr && rq->engine->schedule)
 		rq->engine->schedule(rq, attr);
+	i915_sw_fence_commit(&rq->semaphore);
 	i915_sw_fence_commit(&rq->submit);
 }
 
diff --git a/drivers/gpu/drm/i915/i915_request.h b/drivers/gpu/drm/i915/i915_request.h
index f57eadc..fccc339 100644
--- a/drivers/gpu/drm/i915/i915_request.h
+++ b/drivers/gpu/drm/i915/i915_request.h
@@ -26,6 +26,7 @@
 #define I915_REQUEST_H
 
 #include <linux/dma-fence.h>
+#include <linux/irq_work.h>
 #include <linux/lockdep.h>
 
 #include "gem/i915_gem_context_types.h"
@@ -208,6 +209,7 @@
 	};
 	struct list_head execute_cb;
 	struct i915_sw_fence semaphore;
+	struct irq_work semaphore_work;
 
 	/*
 	 * A list of everyone we wait upon, and everyone who waits upon us.
diff --git a/drivers/gpu/drm/i915/i915_utils.h b/drivers/gpu/drm/i915/i915_utils.h
index b0ade76..d34141f 100644
--- a/drivers/gpu/drm/i915/i915_utils.h
+++ b/drivers/gpu/drm/i915/i915_utils.h
@@ -234,6 +234,11 @@
 	__idx;								\
 })
 
+static inline bool is_power_of_2_u64(u64 n)
+{
+	return (n != 0 && ((n & (n - 1)) == 0));
+}
+
 static inline void __list_del_many(struct list_head *head,
 				   struct list_head *first)
 {