drm/i915: replace for_each_engine()

Having provided for_each_engine_id() for cases where the third (id)
argument is useful, we can now replace all the remaining instances with
a simpler version that takes only two parameters. In many cases, this
also allows the elimination of the local variable used in the iterator
(usually 'i').

v2:
    s/dev_priv/(dev_priv__)/ in body of for_each_engine_masked() [Chris Wilson]

Signed-off-by: Dave Gordon <david.s.gordon@intel.com>
Reviewed-by: Chris Wilson <chris@chris-wilson.co.uk>
Signed-off-by: Tvrtko Ursulin <tvrtko.ursulin@intel.com>
Link: http://patchwork.freedesktop.org/patch/msgid/1458757194-17783-2-git-send-email-david.s.gordon@intel.com

drivers/gpu/drm/i915/i915_debugfs.c

@@ -398,11 +398,11 @@ static void print_batch_pool_stats(struct seq_file *m,
 	struct drm_i915_gem_object *obj;
 	struct file_stats stats;
 	struct intel_engine_cs *engine;
-	int i, j;
+	int j;
 
 	memset(&stats, 0, sizeof(stats));
 
-	for_each_engine(engine, dev_priv, i) {
+	for_each_engine(engine, dev_priv) {
 		for (j = 0; j < ARRAY_SIZE(engine->batch_pool.cache_list); j++) {
 			list_for_each_entry(obj,
 					    &engine->batch_pool.cache_list[j],
@@ -638,13 +638,13 @@ static int i915_gem_batch_pool_info(struct seq_file *m, void *data)
 	struct drm_i915_gem_object *obj;
 	struct intel_engine_cs *engine;
 	int total = 0;
-	int ret, i, j;
+	int ret, j;
 
 	ret = mutex_lock_interruptible(&dev->struct_mutex);
 	if (ret)
 		return ret;
 
-	for_each_engine(engine, dev_priv, i) {
+	for_each_engine(engine, dev_priv) {
 		for (j = 0; j < ARRAY_SIZE(engine->batch_pool.cache_list); j++) {
 			int count;
 
@@ -682,14 +682,14 @@ static int i915_gem_request_info(struct seq_file *m, void *data)
 	struct drm_i915_private *dev_priv = dev->dev_private;
 	struct intel_engine_cs *engine;
 	struct drm_i915_gem_request *req;
-	int ret, any, i;
+	int ret, any;
 
 	ret = mutex_lock_interruptible(&dev->struct_mutex);
 	if (ret)
 		return ret;
 
 	any = 0;
-	for_each_engine(engine, dev_priv, i) {
+	for_each_engine(engine, dev_priv) {
 		int count;
 
 		count = 0;
@@ -739,14 +739,14 @@ static int i915_gem_seqno_info(struct seq_file *m, void *data)
 	struct drm_device *dev = node->minor->dev;
 	struct drm_i915_private *dev_priv = dev->dev_private;
 	struct intel_engine_cs *engine;
-	int ret, i;
+	int ret;
 
 	ret = mutex_lock_interruptible(&dev->struct_mutex);
 	if (ret)
 		return ret;
 	intel_runtime_pm_get(dev_priv);
 
-	for_each_engine(engine, dev_priv, i)
+	for_each_engine(engine, dev_priv)
 		i915_ring_seqno_info(m, engine);
 
 	intel_runtime_pm_put(dev_priv);
@@ -933,7 +933,7 @@ static int i915_interrupt_info(struct seq_file *m, void *data)
 		seq_printf(m, "Graphics Interrupt mask:		%08x\n",
 			   I915_READ(GTIMR));
 	}
-	for_each_engine(engine, dev_priv, i) {
+	for_each_engine(engine, dev_priv) {
 		if (INTEL_INFO(dev)->gen >= 6) {
 			seq_printf(m,
 				   "Graphics Interrupt mask (%s):	%08x\n",
@@ -2044,7 +2044,7 @@ static int i915_dump_lrc(struct seq_file *m, void *unused)
 	struct drm_i915_private *dev_priv = dev->dev_private;
 	struct intel_engine_cs *engine;
 	struct intel_context *ctx;
-	int ret, i;
+	int ret;
 
 	if (!i915.enable_execlists) {
 		seq_printf(m, "Logical Ring Contexts are disabled\n");
@@ -2057,7 +2057,7 @@ static int i915_dump_lrc(struct seq_file *m, void *unused)
 
 	list_for_each_entry(ctx, &dev_priv->context_list, link)
 		if (ctx != dev_priv->kernel_context)
-			for_each_engine(engine, dev_priv, i)
+			for_each_engine(engine, dev_priv)
 				i915_dump_lrc_obj(m, ctx, engine);
 
 	mutex_unlock(&dev->struct_mutex);
@@ -2077,8 +2077,7 @@ static int i915_execlists(struct seq_file *m, void *data)
 	u32 status;
 	u32 ctx_id;
 	struct list_head *cursor;
-	int ring_id, i;
-	int ret;
+	int i, ret;
 
 	if (!i915.enable_execlists) {
 		seq_puts(m, "Logical Ring Contexts are disabled\n");
@@ -2091,7 +2090,7 @@ static int i915_execlists(struct seq_file *m, void *data)
 
 	intel_runtime_pm_get(dev_priv);
 
-	for_each_engine(engine, dev_priv, ring_id) {
+	for_each_engine(engine, dev_priv) {
 		struct drm_i915_gem_request *head_req = NULL;
 		int count = 0;
 		unsigned long flags;
@@ -2250,12 +2249,12 @@ static void gen8_ppgtt_info(struct seq_file *m, struct drm_device *dev)
 	struct drm_i915_private *dev_priv = dev->dev_private;
 	struct intel_engine_cs *engine;
 	struct i915_hw_ppgtt *ppgtt = dev_priv->mm.aliasing_ppgtt;
-	int unused, i;
+	int i;
 
 	if (!ppgtt)
 		return;
 
-	for_each_engine(engine, dev_priv, unused) {
+	for_each_engine(engine, dev_priv) {
 		seq_printf(m, "%s\n", engine->name);
 		for (i = 0; i < 4; i++) {
 			u64 pdp = I915_READ(GEN8_RING_PDP_UDW(engine, i));
@@ -2270,12 +2269,11 @@ static void gen6_ppgtt_info(struct seq_file *m, struct drm_device *dev)
 {
 	struct drm_i915_private *dev_priv = dev->dev_private;
 	struct intel_engine_cs *engine;
-	int i;
 
 	if (INTEL_INFO(dev)->gen == 6)
 		seq_printf(m, "GFX_MODE: 0x%08x\n", I915_READ(GFX_MODE));
 
-	for_each_engine(engine, dev_priv, i) {
+	for_each_engine(engine, dev_priv) {
 		seq_printf(m, "%s\n", engine->name);
 		if (INTEL_INFO(dev)->gen == 7)
 			seq_printf(m, "GFX_MODE: 0x%08x\n",
@@ -2342,9 +2340,8 @@ static int count_irq_waiters(struct drm_i915_private *i915)
 {
 	struct intel_engine_cs *engine;
 	int count = 0;
-	int i;
 
-	for_each_engine(engine, i915, i)
+	for_each_engine(engine, i915)
 		count += engine->irq_refcount;
 
 	return count;
@@ -2455,7 +2452,6 @@ static void i915_guc_client_info(struct seq_file *m,
 {
 	struct intel_engine_cs *engine;
 	uint64_t tot = 0;
-	uint32_t i;
 
 	seq_printf(m, "\tPriority %d, GuC ctx index: %u, PD offset 0x%x\n",
 		client->priority, client->ctx_index, client->proc_desc_offset);
@@ -2468,7 +2464,7 @@ static void i915_guc_client_info(struct seq_file *m,
 	seq_printf(m, "\tFailed doorbell: %u\n", client->b_fail);
 	seq_printf(m, "\tLast submission result: %d\n", client->retcode);
 
-	for_each_engine(engine, dev_priv, i) {
+	for_each_engine(engine, dev_priv) {
 		seq_printf(m, "\tSubmissions: %llu %s\n",
 				client->submissions[engine->guc_id],
 				engine->name);
@@ -2485,7 +2481,6 @@ static int i915_guc_info(struct seq_file *m, void *data)
 	struct intel_guc guc;
 	struct i915_guc_client client = {};
 	struct intel_engine_cs *engine;
-	enum intel_engine_id i;
 	u64 total = 0;
 
 	if (!HAS_GUC_SCHED(dev_priv->dev))
@@ -2508,7 +2503,7 @@ static int i915_guc_info(struct seq_file *m, void *data)
 	seq_printf(m, "GuC last action error code: %d\n", guc.action_err);
 
 	seq_printf(m, "\nGuC submissions:\n");
-	for_each_engine(engine, dev_priv, i) {
+	for_each_engine(engine, dev_priv) {
 		seq_printf(m, "\t%-24s: %10llu, last seqno 0x%08x\n",
 			engine->name, guc.submissions[engine->guc_id],
 			guc.last_seqno[engine->guc_id]);
@@ -3181,7 +3176,7 @@ static int i915_semaphore_status(struct seq_file *m, void *unused)
 		kunmap_atomic(seqno);
 	} else {
 		seq_puts(m, "  Last signal:");
-		for_each_engine(engine, dev_priv, id)
+		for_each_engine(engine, dev_priv)
 			for (j = 0; j < num_rings; j++)
 				seq_printf(m, "0x%08x\n",
 					   I915_READ(engine->semaphore.mbox.signal[j]));
@@ -3189,11 +3184,10 @@ static int i915_semaphore_status(struct seq_file *m, void *unused)
 	}
 
 	seq_puts(m, "\nSync seqno:\n");
-	for_each_engine(engine, dev_priv, id) {
-		for (j = 0; j < num_rings; j++) {
+	for_each_engine(engine, dev_priv) {
+		for (j = 0; j < num_rings; j++)
 			seq_printf(m, "  0x%08x ",
 				   engine->semaphore.sync_seqno[j]);
-		}
 		seq_putc(m, '\n');
 	}
 	seq_putc(m, '\n');

drivers/gpu/drm/i915/i915_drv.h

@@ -1990,10 +1990,12 @@ static inline struct drm_i915_private *guc_to_i915(struct intel_guc *guc)
 	return container_of(guc, struct drm_i915_private, guc);
 }
 
-/* Iterate over initialised rings */
-#define for_each_engine(ring__, dev_priv__, i__) \
-	for ((i__) = 0; (i__) < I915_NUM_ENGINES; (i__)++) \
-		for_each_if ((((ring__) = &(dev_priv__)->engine[(i__)]), intel_engine_initialized((ring__))))
+/* Simple iterator over all initialised engines */
+#define for_each_engine(engine__, dev_priv__) \
+	for ((engine__) = &(dev_priv__)->engine[0]; \
+	     (engine__) < &(dev_priv__)->engine[I915_NUM_ENGINES]; \
+	     (engine__)++) \
+		for_each_if (intel_engine_initialized(engine__))
 
 /* Iterator with engine_id */
 #define for_each_engine_id(engine__, dev_priv__, id__) \
@@ -2005,8 +2007,11 @@ static inline struct drm_i915_private *guc_to_i915(struct intel_guc *guc)
 
 /* Iterator over subset of engines selected by mask */
 #define for_each_engine_masked(engine__, dev_priv__, mask__) \
-	for ((engine__) = &dev_priv->engine[0]; (engine__) < &dev_priv->engine[I915_NUM_ENGINES]; (engine__)++) \
-		for_each_if (intel_engine_flag((engine__)) & (mask__) && intel_engine_initialized((engine__)))
+	for ((engine__) = &(dev_priv__)->engine[0]; \
+	     (engine__) < &(dev_priv__)->engine[I915_NUM_ENGINES]; \
+	     (engine__)++) \
+		for_each_if (((mask__) & intel_engine_flag(engine__)) && \
+			     intel_engine_initialized(engine__))
 
 enum hdmi_force_audio {
 	HDMI_AUDIO_OFF_DVI = -2,	/* no aux data for HDMI-DVI converter */

drivers/gpu/drm/i915/i915_gem.c

@@ -2466,10 +2466,10 @@ i915_gem_init_seqno(struct drm_device *dev, u32 seqno)
 {
 	struct drm_i915_private *dev_priv = dev->dev_private;
 	struct intel_engine_cs *engine;
-	int ret, i, j;
+	int ret, j;
 
 	/* Carefully retire all requests without writing to the rings */
-	for_each_engine(engine, dev_priv, i) {
+	for_each_engine(engine, dev_priv) {
 		ret = intel_engine_idle(engine);
 		if (ret)
 			return ret;
@@ -2477,7 +2477,7 @@ i915_gem_init_seqno(struct drm_device *dev, u32 seqno)
 	i915_gem_retire_requests(dev);
 
 	/* Finally reset hw state */
-	for_each_engine(engine, dev_priv, i) {
+	for_each_engine(engine, dev_priv) {
 		intel_ring_init_seqno(engine, seqno);
 
 		for (j = 0; j < ARRAY_SIZE(engine->semaphore.sync_seqno); j++)
@@ -2884,17 +2884,16 @@ void i915_gem_reset(struct drm_device *dev)
 {
 	struct drm_i915_private *dev_priv = dev->dev_private;
 	struct intel_engine_cs *engine;
-	int i;
 
 	/*
 	 * Before we free the objects from the requests, we need to inspect
 	 * them for finding the guilty party. As the requests only borrow
 	 * their reference to the objects, the inspection must be done first.
 	 */
-	for_each_engine(engine, dev_priv, i)
+	for_each_engine(engine, dev_priv)
 		i915_gem_reset_engine_status(dev_priv, engine);
 
-	for_each_engine(engine, dev_priv, i)
+	for_each_engine(engine, dev_priv)
 		i915_gem_reset_engine_cleanup(dev_priv, engine);
 
 	i915_gem_context_reset(dev);
@@ -2962,9 +2961,8 @@ i915_gem_retire_requests(struct drm_device *dev)
 	struct drm_i915_private *dev_priv = dev->dev_private;
 	struct intel_engine_cs *engine;
 	bool idle = true;
-	int i;
 
-	for_each_engine(engine, dev_priv, i) {
+	for_each_engine(engine, dev_priv) {
 		i915_gem_retire_requests_ring(engine);
 		idle &= list_empty(&engine->request_list);
 		if (i915.enable_execlists) {
@@ -3009,24 +3007,20 @@ i915_gem_idle_work_handler(struct work_struct *work)
 	struct drm_i915_private *dev_priv =
 		container_of(work, typeof(*dev_priv), mm.idle_work.work);
 	struct drm_device *dev = dev_priv->dev;
-	struct intel_engine_cs *ring;
-	int i;
+	struct intel_engine_cs *engine;
 
-	for_each_engine(ring, dev_priv, i)
-		if (!list_empty(&ring->request_list))
+	for_each_engine(engine, dev_priv)
+		if (!list_empty(&engine->request_list))
 			return;
 
 	/* we probably should sync with hangcheck here, using cancel_work_sync.
-	 * Also locking seems to be fubar here, ring->request_list is protected
+	 * Also locking seems to be fubar here, engine->request_list is protected
 	 * by dev->struct_mutex. */
 
 	intel_mark_idle(dev);
 
 	if (mutex_trylock(&dev->struct_mutex)) {
-		struct intel_engine_cs *engine;
-		int i;
-
-		for_each_engine(engine, dev_priv, i)
+		for_each_engine(engine, dev_priv)
 			i915_gem_batch_pool_fini(&engine->batch_pool);
 
 		mutex_unlock(&dev->struct_mutex);
@@ -3390,10 +3384,10 @@ int i915_gpu_idle(struct drm_device *dev)
 {
 	struct drm_i915_private *dev_priv = dev->dev_private;
 	struct intel_engine_cs *engine;
-	int ret, i;
+	int ret;
 
 	/* Flush everything onto the inactive list. */
-	for_each_engine(engine, dev_priv, i) {
+	for_each_engine(engine, dev_priv) {
 		if (!i915.enable_execlists) {
 			struct drm_i915_gem_request *req;
 
@@ -4655,9 +4649,8 @@ i915_gem_stop_engines(struct drm_device *dev)
 {
 	struct drm_i915_private *dev_priv = dev->dev_private;
 	struct intel_engine_cs *engine;
-	int i;
 
-	for_each_engine(engine, dev_priv, i)
+	for_each_engine(engine, dev_priv)
 		dev_priv->gt.stop_engine(engine);
 }
 
@@ -4828,7 +4821,7 @@ i915_gem_init_hw(struct drm_device *dev)
 {
 	struct drm_i915_private *dev_priv = dev->dev_private;
 	struct intel_engine_cs *engine;
-	int ret, i, j;
+	int ret, j;
 
 	if (INTEL_INFO(dev)->gen < 6 && !intel_enable_gtt())
 		return -EIO;
@@ -4874,7 +4867,7 @@ i915_gem_init_hw(struct drm_device *dev)
 	}
 
 	/* Need to do basic initialisation of all rings first: */
-	for_each_engine(engine, dev_priv, i) {
+	for_each_engine(engine, dev_priv) {
 		ret = engine->init_hw(engine);
 		if (ret)
 			goto out;
@@ -4899,7 +4892,7 @@ i915_gem_init_hw(struct drm_device *dev)
 		goto out;
 
 	/* Now it is safe to go back round and do everything else: */
-	for_each_engine(engine, dev_priv, i) {
+	for_each_engine(engine, dev_priv) {
 		struct drm_i915_gem_request *req;
 
 		req = i915_gem_request_alloc(engine, NULL);
@@ -4916,7 +4909,8 @@ i915_gem_init_hw(struct drm_device *dev)
 
 		ret = i915_ppgtt_init_ring(req);
 		if (ret && ret != -EIO) {
-			DRM_ERROR("PPGTT enable ring #%d failed %d\n", i, ret);
+			DRM_ERROR("PPGTT enable %s failed %d\n",
+				  engine->name, ret);
 			i915_gem_request_cancel(req);
 			i915_gem_cleanup_engines(dev);
 			goto out;
@@ -4924,7 +4918,8 @@ i915_gem_init_hw(struct drm_device *dev)
 
 		ret = i915_gem_context_enable(req);
 		if (ret && ret != -EIO) {
-			DRM_ERROR("Context enable ring #%d failed %d\n", i, ret);
+			DRM_ERROR("Context enable %s failed %d\n",
+				  engine->name, ret);
 			i915_gem_request_cancel(req);
 			i915_gem_cleanup_engines(dev);
 			goto out;
@@ -5005,9 +5000,8 @@ i915_gem_cleanup_engines(struct drm_device *dev)
 {
 	struct drm_i915_private *dev_priv = dev->dev_private;
 	struct intel_engine_cs *engine;
-	int i;
 
-	for_each_engine(engine, dev_priv, i)
+	for_each_engine(engine, dev_priv)
 		dev_priv->gt.cleanup_engine(engine);
 
 	if (i915.enable_execlists)

drivers/gpu/drm/i915/i915_gem_context.c

@@ -517,7 +517,7 @@ mi_set_context(struct drm_i915_gem_request *req, u32 hw_flags)
 		i915_semaphore_is_enabled(engine->dev) ?
 		hweight32(INTEL_INFO(engine->dev)->ring_mask) - 1 :
 		0;
-	int len, i, ret;
+	int len, ret;
 
 	/* w/a: If Flush TLB Invalidation Mode is enabled, driver must do a TLB
 	 * invalidation prior to MI_SET_CONTEXT. On GEN6 we don't set the value
@@ -553,7 +553,7 @@ mi_set_context(struct drm_i915_gem_request *req, u32 hw_flags)
 
 			intel_ring_emit(engine,
 					MI_LOAD_REGISTER_IMM(num_rings));
-			for_each_engine(signaller, to_i915(engine->dev), i) {
+			for_each_engine(signaller, to_i915(engine->dev)) {
 				if (signaller == engine)
 					continue;
 
@@ -582,7 +582,7 @@ mi_set_context(struct drm_i915_gem_request *req, u32 hw_flags)
 
 			intel_ring_emit(engine,
 					MI_LOAD_REGISTER_IMM(num_rings));
-			for_each_engine(signaller, to_i915(engine->dev), i) {
+			for_each_engine(signaller, to_i915(engine->dev)) {
 				if (signaller == engine)
 					continue;
 

drivers/gpu/drm/i915/i915_gem_debug.c

@@ -38,12 +38,11 @@ i915_verify_lists(struct drm_device *dev)
 	struct drm_i915_gem_object *obj;
 	struct intel_engine_cs *engine;
 	int err = 0;
-	int i;
 
 	if (warned)
 		return 0;
 
-	for_each_engine(engine, dev_priv, i) {
+	for_each_engine(engine, dev_priv) {
 		list_for_each_entry(obj, &engine->active_list,
 				    engine_list[engine->id]) {
 			if (obj->base.dev != dev ||

drivers/gpu/drm/i915/i915_gem_gtt.c

@@ -1737,9 +1737,8 @@ static void gen8_ppgtt_enable(struct drm_device *dev)
 {
 	struct drm_i915_private *dev_priv = dev->dev_private;
 	struct intel_engine_cs *engine;
-	int j;
 
-	for_each_engine(engine, dev_priv, j) {
+	for_each_engine(engine, dev_priv) {
 		u32 four_level = USES_FULL_48BIT_PPGTT(dev) ? GEN8_GFX_PPGTT_48B : 0;
 		I915_WRITE(RING_MODE_GEN7(engine),
 			   _MASKED_BIT_ENABLE(GFX_PPGTT_ENABLE | four_level));
@@ -1751,7 +1750,6 @@ static void gen7_ppgtt_enable(struct drm_device *dev)
 	struct drm_i915_private *dev_priv = dev->dev_private;
 	struct intel_engine_cs *engine;
 	uint32_t ecochk, ecobits;
-	int i;
 
 	ecobits = I915_READ(GAC_ECO_BITS);
 	I915_WRITE(GAC_ECO_BITS, ecobits | ECOBITS_PPGTT_CACHE64B);
@@ -1765,7 +1763,7 @@ static void gen7_ppgtt_enable(struct drm_device *dev)
 	}
 	I915_WRITE(GAM_ECOCHK, ecochk);
 
-	for_each_engine(engine, dev_priv, i) {
+	for_each_engine(engine, dev_priv) {
 		/* GFX_MODE is per-ring on gen7+ */
 		I915_WRITE(RING_MODE_GEN7(engine),
 			   _MASKED_BIT_ENABLE(GFX_PPGTT_ENABLE));
@@ -2287,12 +2285,11 @@ void i915_check_and_clear_faults(struct drm_device *dev)
 {
 	struct drm_i915_private *dev_priv = dev->dev_private;
 	struct intel_engine_cs *engine;
-	int i;
 
 	if (INTEL_INFO(dev)->gen < 6)
 		return;
 
-	for_each_engine(engine, dev_priv, i) {
+	for_each_engine(engine, dev_priv) {
 		u32 fault_reg;
 		fault_reg = I915_READ(RING_FAULT_REG(engine));
 		if (fault_reg & RING_FAULT_VALID) {

drivers/gpu/drm/i915/i915_guc_submission.c

@@ -842,7 +842,7 @@ static void guc_create_ads(struct intel_guc *guc)
 	struct guc_mmio_reg_state *reg_state;
 	struct intel_engine_cs *engine;
 	struct page *page;
-	u32 size, i;
+	u32 size;
 
 	/* The ads obj includes the struct itself and buffers passed to GuC */
 	size = sizeof(struct guc_ads) + sizeof(struct guc_policies) +
@@ -871,7 +871,7 @@ static void guc_create_ads(struct intel_guc *guc)
 	engine = &dev_priv->engine[RCS];
 	ads->golden_context_lrca = engine->status_page.gfx_addr;
 
-	for_each_engine(engine, dev_priv, i)
+	for_each_engine(engine, dev_priv)
 		ads->eng_state_size[engine->guc_id] = intel_lr_context_size(engine);
 
 	/* GuC scheduling policies */
@@ -884,7 +884,7 @@ static void guc_create_ads(struct intel_guc *guc)
 	/* MMIO reg state */
 	reg_state = (void *)policies + sizeof(struct guc_policies);
 
-	for_each_engine(engine, dev_priv, i) {
+	for_each_engine(engine, dev_priv) {
 		reg_state->mmio_white_list[engine->guc_id].mmio_start =
 			engine->mmio_base + GUC_MMIO_WHITE_LIST_START;
 

drivers/gpu/drm/i915/i915_irq.c

@@ -1080,9 +1080,8 @@ static u32 vlv_wa_c0_ei(struct drm_i915_private *dev_priv, u32 pm_iir)
 static bool any_waiters(struct drm_i915_private *dev_priv)
 {
 	struct intel_engine_cs *engine;
-	int i;
 
-	for_each_engine(engine, dev_priv, i)
+	for_each_engine(engine, dev_priv)
 		if (engine->irq_refcount)
 			return true;
 
@@ -2450,7 +2449,6 @@ static void i915_error_wake_up(struct drm_i915_private *dev_priv,
 			       bool reset_completed)
 {
 	struct intel_engine_cs *engine;
-	int i;
 
 	/*
 	 * Notify all waiters for GPU completion events that reset state has
@@ -2460,7 +2458,7 @@ static void i915_error_wake_up(struct drm_i915_private *dev_priv,
 	 */
 
 	/* Wake up __wait_seqno, potentially holding dev->struct_mutex. */
-	for_each_engine(engine, dev_priv, i)
+	for_each_engine(engine, dev_priv)
 		wake_up_all(&engine->irq_queue);
 
 	/* Wake up intel_crtc_wait_for_pending_flips, holding crtc->mutex. */
@@ -2829,10 +2827,9 @@ semaphore_wait_to_signaller_ring(struct intel_engine_cs *engine, u32 ipehr,
 {
 	struct drm_i915_private *dev_priv = engine->dev->dev_private;
 	struct intel_engine_cs *signaller;
-	int i;
 
 	if (INTEL_INFO(dev_priv->dev)->gen >= 8) {
-		for_each_engine(signaller, dev_priv, i) {
+		for_each_engine(signaller, dev_priv) {
 			if (engine == signaller)
 				continue;
 
@@ -2842,7 +2839,7 @@ semaphore_wait_to_signaller_ring(struct intel_engine_cs *engine, u32 ipehr,
 	} else {
 		u32 sync_bits = ipehr & MI_SEMAPHORE_SYNC_MASK;
 
-		for_each_engine(signaller, dev_priv, i) {
+		for_each_engine(signaller, dev_priv) {
 			if(engine == signaller)
 				continue;
 
@@ -2958,9 +2955,8 @@ static int semaphore_passed(struct intel_engine_cs *engine)
 static void semaphore_clear_deadlocks(struct drm_i915_private *dev_priv)
 {
 	struct intel_engine_cs *engine;
-	int i;
 
-	for_each_engine(engine, dev_priv, i)
+	for_each_engine(engine, dev_priv)
 		engine->hangcheck.deadlock = 0;
 }
 

drivers/gpu/drm/i915/intel_guc_loader.c

@@ -82,12 +82,12 @@ const char *intel_guc_fw_status_repr(enum intel_guc_fw_status status)
 static void direct_interrupts_to_host(struct drm_i915_private *dev_priv)
 {
 	struct intel_engine_cs *engine;
-	int i, irqs;
+	int irqs;
 
 	/* tell all command streamers NOT to forward interrupts and vblank to GuC */
 	irqs = _MASKED_FIELD(GFX_FORWARD_VBLANK_MASK, GFX_FORWARD_VBLANK_NEVER);
 	irqs |= _MASKED_BIT_DISABLE(GFX_INTERRUPT_STEERING);
-	for_each_engine(engine, dev_priv, i)
+	for_each_engine(engine, dev_priv)
 		I915_WRITE(RING_MODE_GEN7(engine), irqs);
 
 	/* route all GT interrupts to the host */
@@ -99,12 +99,12 @@ static void direct_interrupts_to_host(struct drm_i915_private *dev_priv)
 static void direct_interrupts_to_guc(struct drm_i915_private *dev_priv)
 {
 	struct intel_engine_cs *engine;
-	int i, irqs;
+	int irqs;
 
 	/* tell all command streamers to forward interrupts and vblank to GuC */
 	irqs = _MASKED_FIELD(GFX_FORWARD_VBLANK_MASK, GFX_FORWARD_VBLANK_ALWAYS);
 	irqs |= _MASKED_BIT_ENABLE(GFX_INTERRUPT_STEERING);
-	for_each_engine(engine, dev_priv, i)
+	for_each_engine(engine, dev_priv)
 		I915_WRITE(RING_MODE_GEN7(engine), irqs);
 
 	/* route USER_INTERRUPT to Host, all others are sent to GuC. */

drivers/gpu/drm/i915/intel_lrc.c

@@ -2673,9 +2673,8 @@ void intel_lr_context_reset(struct drm_device *dev,
 {
 	struct drm_i915_private *dev_priv = dev->dev_private;
 	struct intel_engine_cs *engine;
-	int i;
 
-	for_each_engine(engine, dev_priv, i) {
+	for_each_engine(engine, dev_priv) {
 		struct drm_i915_gem_object *ctx_obj =
 				ctx->engine[engine->id].state;
 		struct intel_ringbuffer *ringbuf =

drivers/gpu/drm/i915/intel_pm.c

@@ -4817,7 +4817,6 @@ static void gen9_enable_rc6(struct drm_device *dev)
 	struct drm_i915_private *dev_priv = dev->dev_private;
 	struct intel_engine_cs *engine;
 	uint32_t rc6_mask = 0;
-	int unused;
 
 	/* 1a: Software RC state - RC0 */
 	I915_WRITE(GEN6_RC_STATE, 0);
@@ -4838,7 +4837,7 @@ static void gen9_enable_rc6(struct drm_device *dev)
 		I915_WRITE(GEN6_RC6_WAKE_RATE_LIMIT, 54 << 16);
 	I915_WRITE(GEN6_RC_EVALUATION_INTERVAL, 125000); /* 12500 * 1280ns */
 	I915_WRITE(GEN6_RC_IDLE_HYSTERSIS, 25); /* 25 * 1280ns */
-	for_each_engine(engine, dev_priv, unused)
+	for_each_engine(engine, dev_priv)
 		I915_WRITE(RING_MAX_IDLE(engine->mmio_base), 10);
 
 	if (HAS_GUC_UCODE(dev))
@@ -4887,7 +4886,6 @@ static void gen8_enable_rps(struct drm_device *dev)
 	struct drm_i915_private *dev_priv = dev->dev_private;
 	struct intel_engine_cs *engine;
 	uint32_t rc6_mask = 0;
-	int unused;
 
 	/* 1a: Software RC state - RC0 */
 	I915_WRITE(GEN6_RC_STATE, 0);
@@ -4906,7 +4904,7 @@ static void gen8_enable_rps(struct drm_device *dev)
 	I915_WRITE(GEN6_RC6_WAKE_RATE_LIMIT, 40 << 16);
 	I915_WRITE(GEN6_RC_EVALUATION_INTERVAL, 125000); /* 12500 * 1280ns */
 	I915_WRITE(GEN6_RC_IDLE_HYSTERSIS, 25); /* 25 * 1280ns */
-	for_each_engine(engine, dev_priv, unused)
+	for_each_engine(engine, dev_priv)
 		I915_WRITE(RING_MAX_IDLE(engine->mmio_base), 10);
 	I915_WRITE(GEN6_RC_SLEEP, 0);
 	if (IS_BROADWELL(dev))
@@ -4971,7 +4969,7 @@ static void gen6_enable_rps(struct drm_device *dev)
 	u32 rc6vids, pcu_mbox = 0, rc6_mask = 0;
 	u32 gtfifodbg;
 	int rc6_mode;
-	int i, ret;
+	int ret;
 
 	WARN_ON(!mutex_is_locked(&dev_priv->rps.hw_lock));
 
@@ -5003,7 +5001,7 @@ static void gen6_enable_rps(struct drm_device *dev)
 	I915_WRITE(GEN6_RC_EVALUATION_INTERVAL, 125000);
 	I915_WRITE(GEN6_RC_IDLE_HYSTERSIS, 25);
 
-	for_each_engine(engine, dev_priv, i)
+	for_each_engine(engine, dev_priv)
 		I915_WRITE(RING_MAX_IDLE(engine->mmio_base), 10);
 
 	I915_WRITE(GEN6_RC_SLEEP, 0);
@@ -5497,7 +5495,6 @@ static void cherryview_enable_rps(struct drm_device *dev)
 	struct drm_i915_private *dev_priv = dev->dev_private;
 	struct intel_engine_cs *engine;
 	u32 gtfifodbg, val, rc6_mode = 0, pcbr;
-	int i;
 
 	WARN_ON(!mutex_is_locked(&dev_priv->rps.hw_lock));
 
@@ -5522,7 +5519,7 @@ static void cherryview_enable_rps(struct drm_device *dev)
 	I915_WRITE(GEN6_RC_EVALUATION_INTERVAL, 125000); /* 12500 * 1280ns */
 	I915_WRITE(GEN6_RC_IDLE_HYSTERSIS, 25); /* 25 * 1280ns */
 
-	for_each_engine(engine, dev_priv, i)
+	for_each_engine(engine, dev_priv)
 		I915_WRITE(RING_MAX_IDLE(engine->mmio_base), 10);
 	I915_WRITE(GEN6_RC_SLEEP, 0);
 
@@ -5595,7 +5592,6 @@ static void valleyview_enable_rps(struct drm_device *dev)
 	struct drm_i915_private *dev_priv = dev->dev_private;
 	struct intel_engine_cs *engine;
 	u32 gtfifodbg, val, rc6_mode = 0;
-	int i;
 
 	WARN_ON(!mutex_is_locked(&dev_priv->rps.hw_lock));
 
@@ -5633,7 +5629,7 @@ static void valleyview_enable_rps(struct drm_device *dev)
 	I915_WRITE(GEN6_RC_EVALUATION_INTERVAL, 125000);
 	I915_WRITE(GEN6_RC_IDLE_HYSTERSIS, 25);
 
-	for_each_engine(engine, dev_priv, i)
+	for_each_engine(engine, dev_priv)
 		I915_WRITE(RING_MAX_IDLE(engine->mmio_base), 10);
 
 	I915_WRITE(GEN6_RC6_THRESHOLD, 0x557);
@@ -6012,14 +6008,13 @@ bool i915_gpu_busy(void)
 	struct drm_i915_private *dev_priv;
 	struct intel_engine_cs *engine;
 	bool ret = false;
-	int i;
 
 	spin_lock_irq(&mchdev_lock);
 	if (!i915_mch_dev)
 		goto out_unlock;
 	dev_priv = i915_mch_dev;
 
-	for_each_engine(engine, dev_priv, i)
+	for_each_engine(engine, dev_priv)
 		ret |= !list_empty(&engine->request_list);
 
 out_unlock: