drm/i915: introduce for_each_engine_id()

Equivalent to the existing for_each_engine() macro, this will replace
the latter wherever the third argument *is* actually wanted (in most
places, it is not used). The third argument is renamed to emphasise
that it is an engine id (type enum intel_engine_id). All the callers of
the macro that actually need the third argument are updated to use this
version, and the argument (generally 'i') is also updated to be 'id'.
Other callers (where the third argument is unused) are untouched for
now; they will be updated in the next patch.

Signed-off-by: Dave Gordon <david.s.gordon@intel.com>
Signed-off-by: Tvrtko Ursulin <tvrtko.ursulin@intel.com>
Reviewed-by: Chris Wilson <chris@chris-wilson.co.uk>
diff --git a/drivers/gpu/drm/i915/i915_debugfs.c b/drivers/gpu/drm/i915/i915_debugfs.c
index e0ba3e3..77dce52 100644
--- a/drivers/gpu/drm/i915/i915_debugfs.c
+++ b/drivers/gpu/drm/i915/i915_debugfs.c
@@ -132,7 +132,7 @@
 	struct intel_engine_cs *engine;
 	struct i915_vma *vma;
 	int pin_count = 0;
-	int i;
+	enum intel_engine_id id;
 
 	seq_printf(m, "%pK: %s%s%s%s %8zdKiB %02x %02x [ ",
 		   &obj->base,
@@ -143,9 +143,9 @@
 		   obj->base.size / 1024,
 		   obj->base.read_domains,
 		   obj->base.write_domain);
-	for_each_engine(engine, dev_priv, i)
+	for_each_engine_id(engine, dev_priv, id)
 		seq_printf(m, "%x ",
-				i915_gem_request_get_seqno(obj->last_read_req[i]));
+				i915_gem_request_get_seqno(obj->last_read_req[id]));
 	seq_printf(m, "] %x %x%s%s%s",
 		   i915_gem_request_get_seqno(obj->last_write_req),
 		   i915_gem_request_get_seqno(obj->last_fenced_req),
@@ -1334,7 +1334,8 @@
 	u64 acthd[I915_NUM_ENGINES];
 	u32 seqno[I915_NUM_ENGINES];
 	u32 instdone[I915_NUM_INSTDONE_REG];
-	int i, j;
+	enum intel_engine_id id;
+	int j;
 
 	if (!i915.enable_hangcheck) {
 		seq_printf(m, "Hangcheck disabled\n");
@@ -1343,9 +1344,9 @@
 
 	intel_runtime_pm_get(dev_priv);
 
-	for_each_engine(engine, dev_priv, i) {
-		seqno[i] = engine->get_seqno(engine, false);
-		acthd[i] = intel_ring_get_active_head(engine);
+	for_each_engine_id(engine, dev_priv, id) {
+		seqno[id] = engine->get_seqno(engine, false);
+		acthd[id] = intel_ring_get_active_head(engine);
 	}
 
 	i915_get_extra_instdone(dev, instdone);
@@ -1359,13 +1360,13 @@
 	} else
 		seq_printf(m, "Hangcheck inactive\n");
 
-	for_each_engine(engine, dev_priv, i) {
+	for_each_engine_id(engine, dev_priv, id) {
 		seq_printf(m, "%s:\n", engine->name);
 		seq_printf(m, "\tseqno = %x [current %x]\n",
-			   engine->hangcheck.seqno, seqno[i]);
+			   engine->hangcheck.seqno, seqno[id]);
 		seq_printf(m, "\tACTHD = 0x%08llx [current 0x%08llx]\n",
 			   (long long)engine->hangcheck.acthd,
-			   (long long)acthd[i]);
+			   (long long)acthd[id]);
 		seq_printf(m, "\tscore = %d\n", engine->hangcheck.score);
 		seq_printf(m, "\taction = %d\n", engine->hangcheck.action);
 
@@ -1947,7 +1948,8 @@
 	struct drm_i915_private *dev_priv = dev->dev_private;
 	struct intel_engine_cs *engine;
 	struct intel_context *ctx;
-	int ret, i;
+	enum intel_engine_id id;
+	int ret;
 
 	ret = mutex_lock_interruptible(&dev->struct_mutex);
 	if (ret)
@@ -1965,11 +1967,11 @@
 
 		if (i915.enable_execlists) {
 			seq_putc(m, '\n');
-			for_each_engine(engine, dev_priv, i) {
+			for_each_engine_id(engine, dev_priv, id) {
 				struct drm_i915_gem_object *ctx_obj =
-					ctx->engine[i].state;
+					ctx->engine[id].state;
 				struct intel_ringbuffer *ringbuf =
-					ctx->engine[i].ringbuf;
+					ctx->engine[id].ringbuf;
 
 				seq_printf(m, "%s: ", engine->name);
 				if (ctx_obj)
@@ -3134,7 +3136,8 @@
 	struct drm_i915_private *dev_priv = dev->dev_private;
 	struct intel_engine_cs *engine;
 	int num_rings = hweight32(INTEL_INFO(dev)->ring_mask);
-	int i, j, ret;
+	enum intel_engine_id id;
+	int j, ret;
 
 	if (!i915_semaphore_is_enabled(dev)) {
 		seq_puts(m, "Semaphores are disabled\n");
@@ -3153,14 +3156,14 @@
 		page = i915_gem_object_get_page(dev_priv->semaphore_obj, 0);
 
 		seqno = (uint64_t *)kmap_atomic(page);
-		for_each_engine(engine, dev_priv, i) {
+		for_each_engine_id(engine, dev_priv, id) {
 			uint64_t offset;
 
 			seq_printf(m, "%s\n", engine->name);
 
 			seq_puts(m, "  Last signal:");
 			for (j = 0; j < num_rings; j++) {
-				offset = i * I915_NUM_ENGINES + j;
+				offset = id * I915_NUM_ENGINES + j;
 				seq_printf(m, "0x%08llx (0x%02llx) ",
 					   seqno[offset], offset * 8);
 			}
@@ -3168,7 +3171,7 @@
 
 			seq_puts(m, "  Last wait:  ");
 			for (j = 0; j < num_rings; j++) {
-				offset = i + (j * I915_NUM_ENGINES);
+				offset = id + (j * I915_NUM_ENGINES);
 				seq_printf(m, "0x%08llx (0x%02llx) ",
 					   seqno[offset], offset * 8);
 			}
@@ -3178,7 +3181,7 @@
 		kunmap_atomic(seqno);
 	} else {
 		seq_puts(m, "  Last signal:");
-		for_each_engine(engine, dev_priv, i)
+		for_each_engine(engine, dev_priv, id)
 			for (j = 0; j < num_rings; j++)
 				seq_printf(m, "0x%08x\n",
 					   I915_READ(engine->semaphore.mbox.signal[j]));
@@ -3186,7 +3189,7 @@
 	}
 
 	seq_puts(m, "\nSync seqno:\n");
-	for_each_engine(engine, dev_priv, i) {
+	for_each_engine(engine, dev_priv, id) {
 		for (j = 0; j < num_rings; j++) {
 			seq_printf(m, "  0x%08x ",
 				   engine->semaphore.sync_seqno[j]);
@@ -3236,6 +3239,7 @@
 	struct drm_device *dev = node->minor->dev;
 	struct drm_i915_private *dev_priv = dev->dev_private;
 	struct i915_workarounds *workarounds = &dev_priv->workarounds;
+	enum intel_engine_id id;
 
 	ret = mutex_lock_interruptible(&dev->struct_mutex);
 	if (ret)
@@ -3244,9 +3248,9 @@
 	intel_runtime_pm_get(dev_priv);
 
 	seq_printf(m, "Workarounds applied: %d\n", workarounds->count);
-	for_each_engine(engine, dev_priv, i)
+	for_each_engine_id(engine, dev_priv, id)
 		seq_printf(m, "HW whitelist count for %s: %d\n",
-			   engine->name, workarounds->hw_whitelist_count[i]);
+			   engine->name, workarounds->hw_whitelist_count[id]);
 	for (i = 0; i < workarounds->count; ++i) {
 		i915_reg_t addr;
 		u32 mask, value, read;
diff --git a/drivers/gpu/drm/i915/i915_drv.h b/drivers/gpu/drm/i915/i915_drv.h
index 08b88c0..8fe0592 100644
--- a/drivers/gpu/drm/i915/i915_drv.h
+++ b/drivers/gpu/drm/i915/i915_drv.h
@@ -1995,6 +1995,15 @@
 	for ((i__) = 0; (i__) < I915_NUM_ENGINES; (i__)++) \
 		for_each_if ((((ring__) = &(dev_priv__)->engine[(i__)]), intel_engine_initialized((ring__))))
 
+/* Iterator with engine_id */
+#define for_each_engine_id(engine__, dev_priv__, id__) \
+	for ((engine__) = &(dev_priv__)->engine[0], (id__) = 0; \
+	     (engine__) < &(dev_priv__)->engine[I915_NUM_ENGINES]; \
+	     (engine__)++) \
+		for_each_if (((id__) = (engine__)->id, \
+			      intel_engine_initialized(engine__)))
+
+/* 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__)))
diff --git a/drivers/gpu/drm/i915/i915_gpu_error.c b/drivers/gpu/drm/i915/i915_gpu_error.c
index 1f8ff06..54c2086 100644
--- a/drivers/gpu/drm/i915/i915_gpu_error.c
+++ b/drivers/gpu/drm/i915/i915_gpu_error.c
@@ -846,7 +846,7 @@
 					struct drm_i915_error_ring *ering)
 {
 	struct intel_engine_cs *to;
-	int i;
+	enum intel_engine_id id;
 
 	if (!i915_semaphore_is_enabled(dev_priv->dev))
 		return;
@@ -856,7 +856,7 @@
 			i915_error_ggtt_object_create(dev_priv,
 						      dev_priv->semaphore_obj);
 
-	for_each_engine(to, dev_priv, i) {
+	for_each_engine_id(to, dev_priv, id) {
 		int idx;
 		u16 signal_offset;
 		u32 *tmp;
@@ -864,7 +864,7 @@
 		if (engine == to)
 			continue;
 
-		signal_offset = (GEN8_SIGNAL_OFFSET(engine, i) & (PAGE_SIZE - 1))
+		signal_offset = (GEN8_SIGNAL_OFFSET(engine, id) & (PAGE_SIZE - 1))
 				/ 4;
 		tmp = error->semaphore_obj->pages[0];
 		idx = intel_ring_sync_index(engine, to);
diff --git a/drivers/gpu/drm/i915/i915_guc_submission.c b/drivers/gpu/drm/i915/i915_guc_submission.c
index ae1f58d..0611bdc 100644
--- a/drivers/gpu/drm/i915/i915_guc_submission.c
+++ b/drivers/gpu/drm/i915/i915_guc_submission.c
@@ -381,7 +381,7 @@
 	struct intel_context *ctx = client->owner;
 	struct guc_context_desc desc;
 	struct sg_table *sg;
-	int i;
+	enum intel_engine_id id;
 
 	memset(&desc, 0, sizeof(desc));
 
@@ -390,7 +390,7 @@
 	desc.priority = client->priority;
 	desc.db_id = client->doorbell_id;
 
-	for_each_engine(engine, dev_priv, i) {
+	for_each_engine_id(engine, dev_priv, id) {
 		struct guc_execlist_context *lrc = &desc.lrc[engine->guc_id];
 		struct drm_i915_gem_object *obj;
 		uint64_t ctx_desc;
@@ -402,7 +402,7 @@
 		 * for now who owns a GuC client. But for future owner of GuC
 		 * client, need to make sure lrc is pinned prior to enter here.
 		 */
-		obj = ctx->engine[i].state;
+		obj = ctx->engine[id].state;
 		if (!obj)
 			break;	/* XXX: continue? */
 
@@ -415,7 +415,7 @@
 		lrc->context_id = (client->ctx_index << GUC_ELC_CTXID_OFFSET) |
 				(engine->guc_id << GUC_ELC_ENGINE_OFFSET);
 
-		obj = ctx->engine[i].ringbuf->obj;
+		obj = ctx->engine[id].ringbuf->obj;
 
 		lrc->ring_begin = i915_gem_obj_ggtt_offset(obj);
 		lrc->ring_end = lrc->ring_begin + obj->base.size - 1;
diff --git a/drivers/gpu/drm/i915/i915_irq.c b/drivers/gpu/drm/i915/i915_irq.c
index a55a7cc..14a23b3 100644
--- a/drivers/gpu/drm/i915/i915_irq.c
+++ b/drivers/gpu/drm/i915/i915_irq.c
@@ -3073,7 +3073,7 @@
 			     gpu_error.hangcheck_work.work);
 	struct drm_device *dev = dev_priv->dev;
 	struct intel_engine_cs *engine;
-	int i;
+	enum intel_engine_id id;
 	int busy_count = 0, rings_hung = 0;
 	bool stuck[I915_NUM_ENGINES] = { 0 };
 #define BUSY 1
@@ -3097,7 +3097,7 @@
 	 */
 	intel_uncore_arm_unclaimed_mmio_detection(dev_priv);
 
-	for_each_engine(engine, dev_priv, i) {
+	for_each_engine_id(engine, dev_priv, id) {
 		u64 acthd;
 		u32 seqno;
 		bool busy = true;
@@ -3157,7 +3157,7 @@
 					break;
 				case HANGCHECK_HUNG:
 					engine->hangcheck.score += HUNG;
-					stuck[i] = true;
+					stuck[id] = true;
 					break;
 				}
 			}
@@ -3184,10 +3184,10 @@
 		busy_count += busy;
 	}
 
-	for_each_engine(engine, dev_priv, i) {
+	for_each_engine_id(engine, dev_priv, id) {
 		if (engine->hangcheck.score >= HANGCHECK_SCORE_RING_HUNG) {
 			DRM_INFO("%s on %s\n",
-				 stuck[i] ? "stuck" : "no progress",
+				 stuck[id] ? "stuck" : "no progress",
 				 engine->name);
 			rings_hung |= intel_engine_flag(engine);
 		}
diff --git a/drivers/gpu/drm/i915/intel_mocs.c b/drivers/gpu/drm/i915/intel_mocs.c
index 3c725dd..7c7ac0a 100644
--- a/drivers/gpu/drm/i915/intel_mocs.c
+++ b/drivers/gpu/drm/i915/intel_mocs.c
@@ -325,11 +325,11 @@
 	if (get_mocs_settings(req->engine->dev, &t)) {
 		struct drm_i915_private *dev_priv = req->i915;
 		struct intel_engine_cs *engine;
-		enum intel_engine_id ring_id;
+		enum intel_engine_id id;
 
 		/* Program the control registers */
-		for_each_engine(engine, dev_priv, ring_id) {
-			ret = emit_mocs_control_table(req, &t, ring_id);
+		for_each_engine_id(engine, dev_priv, id) {
+			ret = emit_mocs_control_table(req, &t, id);
 			if (ret)
 				return ret;
 		}
diff --git a/drivers/gpu/drm/i915/intel_ringbuffer.c b/drivers/gpu/drm/i915/intel_ringbuffer.c
index ce59850..a492bca 100644
--- a/drivers/gpu/drm/i915/intel_ringbuffer.c
+++ b/drivers/gpu/drm/i915/intel_ringbuffer.c
@@ -1280,7 +1280,8 @@
 	struct drm_device *dev = signaller->dev;
 	struct drm_i915_private *dev_priv = dev->dev_private;
 	struct intel_engine_cs *waiter;
-	int i, ret, num_rings;
+	enum intel_engine_id id;
+	int ret, num_rings;
 
 	num_rings = hweight32(INTEL_INFO(dev)->ring_mask);
 	num_dwords += (num_rings-1) * MBOX_UPDATE_DWORDS;
@@ -1290,9 +1291,9 @@
 	if (ret)
 		return ret;
 
-	for_each_engine(waiter, dev_priv, i) {
+	for_each_engine_id(waiter, dev_priv, id) {
 		u32 seqno;
-		u64 gtt_offset = signaller->semaphore.signal_ggtt[i];
+		u64 gtt_offset = signaller->semaphore.signal_ggtt[id];
 		if (gtt_offset == MI_SEMAPHORE_SYNC_INVALID)
 			continue;
 
@@ -1321,7 +1322,8 @@
 	struct drm_device *dev = signaller->dev;
 	struct drm_i915_private *dev_priv = dev->dev_private;
 	struct intel_engine_cs *waiter;
-	int i, ret, num_rings;
+	enum intel_engine_id id;
+	int ret, num_rings;
 
 	num_rings = hweight32(INTEL_INFO(dev)->ring_mask);
 	num_dwords += (num_rings-1) * MBOX_UPDATE_DWORDS;
@@ -1331,9 +1333,9 @@
 	if (ret)
 		return ret;
 
-	for_each_engine(waiter, dev_priv, i) {
+	for_each_engine_id(waiter, dev_priv, id) {
 		u32 seqno;
-		u64 gtt_offset = signaller->semaphore.signal_ggtt[i];
+		u64 gtt_offset = signaller->semaphore.signal_ggtt[id];
 		if (gtt_offset == MI_SEMAPHORE_SYNC_INVALID)
 			continue;
 
@@ -1359,7 +1361,8 @@
 	struct drm_device *dev = signaller->dev;
 	struct drm_i915_private *dev_priv = dev->dev_private;
 	struct intel_engine_cs *useless;
-	int i, ret, num_rings;
+	enum intel_engine_id id;
+	int ret, num_rings;
 
 #define MBOX_UPDATE_DWORDS 3
 	num_rings = hweight32(INTEL_INFO(dev)->ring_mask);
@@ -1370,8 +1373,8 @@
 	if (ret)
 		return ret;
 
-	for_each_engine(useless, dev_priv, i) {
-		i915_reg_t mbox_reg = signaller->semaphore.mbox.signal[i];
+	for_each_engine_id(useless, dev_priv, id) {
+		i915_reg_t mbox_reg = signaller->semaphore.mbox.signal[id];
 
 		if (i915_mmio_reg_valid(mbox_reg)) {
 			u32 seqno = i915_gem_request_get_seqno(signaller_req);