drm/i915:Initialize the second BSD ring on BDW GT3 machine

Based on the hardware spec, the BDW GT3 machine has two independent
BSD ring that can be used to dispatch the video commands.
So just initialize it.

V3->V4: Follow Imre's comment to do some minor updates. For example:
more comments are added to describe the semaphore between ring.
Reviewed-by: NImre Deak <imre.deak@intel.com>
Signed-off-by: NZhao Yakui <yakui.zhao@intel.com>
[danvet: Fix up checkpatch error.]
Signed-off-by: NDaniel Vetter <daniel.vetter@ffwll.ch>

drivers/gpu/drm/i915/i915_drv.c

@@ -282,7 +282,7 @@ static const struct intel_device_info intel_broadwell_m_info = {
 static const struct intel_device_info intel_broadwell_gt3d_info = {
 	.gen = 8, .num_pipes = 3,
 	.need_gfx_hws = 1, .has_hotplug = 1,
-	.ring_mask = RENDER_RING | BSD_RING | BLT_RING | VEBOX_RING,
+	.ring_mask = RENDER_RING | BSD_RING | BLT_RING | VEBOX_RING | BSD2_RING,
 	.has_llc = 1,
 	.has_ddi = 1,
 	.has_fbc = 1,
@@ -292,7 +292,7 @@ static const struct intel_device_info intel_broadwell_gt3d_info = {
 static const struct intel_device_info intel_broadwell_gt3m_info = {
 	.gen = 8, .is_mobile = 1, .num_pipes = 3,
 	.need_gfx_hws = 1, .has_hotplug = 1,
-	.ring_mask = RENDER_RING | BSD_RING | BLT_RING | VEBOX_RING,
+	.ring_mask = RENDER_RING | BSD_RING | BLT_RING | VEBOX_RING | BSD2_RING,
 	.has_llc = 1,
 	.has_ddi = 1,
 	.has_fbc = 1,

drivers/gpu/drm/i915/i915_drv.h

@@ -1834,7 +1834,9 @@ struct drm_i915_cmd_table {
 #define BSD_RING		(1<<VCS)
 #define BLT_RING		(1<<BCS)
 #define VEBOX_RING		(1<<VECS)
+#define BSD2_RING		(1<<VCS2)
 #define HAS_BSD(dev)            (INTEL_INFO(dev)->ring_mask & BSD_RING)
+#define HAS_BSD2(dev)		(INTEL_INFO(dev)->ring_mask & BSD2_RING)
 #define HAS_BLT(dev)            (INTEL_INFO(dev)->ring_mask & BLT_RING)
 #define HAS_VEBOX(dev)            (INTEL_INFO(dev)->ring_mask & VEBOX_RING)
 #define HAS_LLC(dev)            (INTEL_INFO(dev)->has_llc)

drivers/gpu/drm/i915/i915_gem.c

@@ -4388,13 +4388,20 @@ static int i915_gem_init_rings(struct drm_device *dev)
 			goto cleanup_blt_ring;
 	}
 
+	if (HAS_BSD2(dev)) {
+		ret = intel_init_bsd2_ring_buffer(dev);
+		if (ret)
+			goto cleanup_vebox_ring;
+	}
 
 	ret = i915_gem_set_seqno(dev, ((u32)~0 - 0x1000));
 	if (ret)
-		goto cleanup_vebox_ring;
+		goto cleanup_bsd2_ring;
 
 	return 0;
 
+cleanup_bsd2_ring:
+	intel_cleanup_ring_buffer(&dev_priv->ring[VCS2]);
 cleanup_vebox_ring:
 	intel_cleanup_ring_buffer(&dev_priv->ring[VECS]);
 cleanup_blt_ring:

drivers/gpu/drm/i915/i915_gpu_error.c

@@ -42,6 +42,7 @@ static const char *ring_str(int ring)
 	case VCS: return "bsd";
 	case BCS: return "blt";
 	case VECS: return "vebox";
+	case VCS2: return "bsd2";
 	default: return "";
 	}
 }

drivers/gpu/drm/i915/i915_reg.h

@@ -760,6 +760,7 @@ enum punit_power_well {
 #define RENDER_RING_BASE	0x02000
 #define BSD_RING_BASE		0x04000
 #define GEN6_BSD_RING_BASE	0x12000
+#define GEN8_BSD2_RING_BASE	0x1c000
 #define VEBOX_RING_BASE		0x1a000
 #define BLT_RING_BASE		0x22000
 #define RING_TAIL(base)		((base)+0x30)

drivers/gpu/drm/i915/intel_ringbuffer.c

@@ -1917,14 +1917,22 @@ int intel_init_render_ring_buffer(struct drm_device *dev)
 		ring->get_seqno = gen6_ring_get_seqno;
 		ring->set_seqno = ring_set_seqno;
 		ring->sync_to = gen6_ring_sync;
+		/*
+		 * The current semaphore is only applied on pre-gen8 platform.
+		 * And there is no VCS2 ring on the pre-gen8 platform. So the
+		 * semaphore between RCS and VCS2 is initialized as INVALID.
+		 * Gen8 will initialize the sema between VCS2 and RCS later.
+		 */
 		ring->semaphore_register[RCS] = MI_SEMAPHORE_SYNC_INVALID;
 		ring->semaphore_register[VCS] = MI_SEMAPHORE_SYNC_RV;
 		ring->semaphore_register[BCS] = MI_SEMAPHORE_SYNC_RB;
 		ring->semaphore_register[VECS] = MI_SEMAPHORE_SYNC_RVE;
+		ring->semaphore_register[VCS2] = MI_SEMAPHORE_SYNC_INVALID;
 		ring->signal_mbox[RCS] = GEN6_NOSYNC;
 		ring->signal_mbox[VCS] = GEN6_VRSYNC;
 		ring->signal_mbox[BCS] = GEN6_BRSYNC;
 		ring->signal_mbox[VECS] = GEN6_VERSYNC;
+		ring->signal_mbox[VCS2] = GEN6_NOSYNC;
 	} else if (IS_GEN5(dev)) {
 		ring->add_request = pc_render_add_request;
 		ring->flush = gen4_render_ring_flush;
@@ -2093,14 +2101,22 @@ int intel_init_bsd_ring_buffer(struct drm_device *dev)
 				gen6_ring_dispatch_execbuffer;
 		}
 		ring->sync_to = gen6_ring_sync;
+		/*
+		 * The current semaphore is only applied on pre-gen8 platform.
+		 * And there is no VCS2 ring on the pre-gen8 platform. So the
+		 * semaphore between VCS and VCS2 is initialized as INVALID.
+		 * Gen8 will initialize the sema between VCS2 and VCS later.
+		 */
 		ring->semaphore_register[RCS] = MI_SEMAPHORE_SYNC_VR;
 		ring->semaphore_register[VCS] = MI_SEMAPHORE_SYNC_INVALID;
 		ring->semaphore_register[BCS] = MI_SEMAPHORE_SYNC_VB;
 		ring->semaphore_register[VECS] = MI_SEMAPHORE_SYNC_VVE;
+		ring->semaphore_register[VCS2] = MI_SEMAPHORE_SYNC_INVALID;
 		ring->signal_mbox[RCS] = GEN6_RVSYNC;
 		ring->signal_mbox[VCS] = GEN6_NOSYNC;
 		ring->signal_mbox[BCS] = GEN6_BVSYNC;
 		ring->signal_mbox[VECS] = GEN6_VEVSYNC;
+		ring->signal_mbox[VCS2] = GEN6_NOSYNC;
 	} else {
 		ring->mmio_base = BSD_RING_BASE;
 		ring->flush = bsd_ring_flush;
@@ -2123,6 +2139,58 @@ int intel_init_bsd_ring_buffer(struct drm_device *dev)
 	return intel_init_ring_buffer(dev, ring);
 }
 
+/**
+ * Initialize the second BSD ring for Broadwell GT3.
+ * It is noted that this only exists on Broadwell GT3.
+ */
+int intel_init_bsd2_ring_buffer(struct drm_device *dev)
+{
+	struct drm_i915_private *dev_priv = dev->dev_private;
+	struct intel_ring_buffer *ring = &dev_priv->ring[VCS2];
+
+	if ((INTEL_INFO(dev)->gen != 8)) {
+		DRM_ERROR("No dual-BSD ring on non-BDW machine\n");
+		return -EINVAL;
+	}
+
+	ring->name = "bds2_ring";
+	ring->id = VCS2;
+
+	ring->write_tail = ring_write_tail;
+	ring->mmio_base = GEN8_BSD2_RING_BASE;
+	ring->flush = gen6_bsd_ring_flush;
+	ring->add_request = gen6_add_request;
+	ring->get_seqno = gen6_ring_get_seqno;
+	ring->set_seqno = ring_set_seqno;
+	ring->irq_enable_mask =
+			GT_RENDER_USER_INTERRUPT << GEN8_VCS2_IRQ_SHIFT;
+	ring->irq_get = gen8_ring_get_irq;
+	ring->irq_put = gen8_ring_put_irq;
+	ring->dispatch_execbuffer =
+			gen8_ring_dispatch_execbuffer;
+	ring->sync_to = gen6_ring_sync;
+	/*
+	 * The current semaphore is only applied on the pre-gen8. And there
+	 * is no bsd2 ring on the pre-gen8. So now the semaphore_register
+	 * between VCS2 and other ring is initialized as invalid.
+	 * Gen8 will initialize the sema between VCS2 and other ring later.
+	 */
+	ring->semaphore_register[RCS] = MI_SEMAPHORE_SYNC_INVALID;
+	ring->semaphore_register[VCS] = MI_SEMAPHORE_SYNC_INVALID;
+	ring->semaphore_register[BCS] = MI_SEMAPHORE_SYNC_INVALID;
+	ring->semaphore_register[VECS] = MI_SEMAPHORE_SYNC_INVALID;
+	ring->semaphore_register[VCS2] = MI_SEMAPHORE_SYNC_INVALID;
+	ring->signal_mbox[RCS] = GEN6_NOSYNC;
+	ring->signal_mbox[VCS] = GEN6_NOSYNC;
+	ring->signal_mbox[BCS] = GEN6_NOSYNC;
+	ring->signal_mbox[VECS] = GEN6_NOSYNC;
+	ring->signal_mbox[VCS2] = GEN6_NOSYNC;
+
+	ring->init = init_ring_common;
+
+	return intel_init_ring_buffer(dev, ring);
+}
+
 int intel_init_blt_ring_buffer(struct drm_device *dev)
 {
 	struct drm_i915_private *dev_priv = dev->dev_private;
@@ -2150,14 +2218,22 @@ int intel_init_blt_ring_buffer(struct drm_device *dev)
 		ring->dispatch_execbuffer = gen6_ring_dispatch_execbuffer;
 	}
 	ring->sync_to = gen6_ring_sync;
+	/*
+	 * The current semaphore is only applied on pre-gen8 platform. And
+	 * there is no VCS2 ring on the pre-gen8 platform. So the semaphore
+	 * between BCS and VCS2 is initialized as INVALID.
+	 * Gen8 will initialize the sema between BCS and VCS2 later.
+	 */
 	ring->semaphore_register[RCS] = MI_SEMAPHORE_SYNC_BR;
 	ring->semaphore_register[VCS] = MI_SEMAPHORE_SYNC_BV;
 	ring->semaphore_register[BCS] = MI_SEMAPHORE_SYNC_INVALID;
 	ring->semaphore_register[VECS] = MI_SEMAPHORE_SYNC_BVE;
+	ring->semaphore_register[VCS2] = MI_SEMAPHORE_SYNC_INVALID;
 	ring->signal_mbox[RCS] = GEN6_RBSYNC;
 	ring->signal_mbox[VCS] = GEN6_VBSYNC;
 	ring->signal_mbox[BCS] = GEN6_NOSYNC;
 	ring->signal_mbox[VECS] = GEN6_VEBSYNC;
+	ring->signal_mbox[VCS2] = GEN6_NOSYNC;
 	ring->init = init_ring_common;
 
 	return intel_init_ring_buffer(dev, ring);
@@ -2195,10 +2271,12 @@ int intel_init_vebox_ring_buffer(struct drm_device *dev)
 	ring->semaphore_register[VCS] = MI_SEMAPHORE_SYNC_VEV;
 	ring->semaphore_register[BCS] = MI_SEMAPHORE_SYNC_VEB;
 	ring->semaphore_register[VECS] = MI_SEMAPHORE_SYNC_INVALID;
+	ring->semaphore_register[VCS2] = MI_SEMAPHORE_SYNC_INVALID;
 	ring->signal_mbox[RCS] = GEN6_RVESYNC;
 	ring->signal_mbox[VCS] = GEN6_VVESYNC;
 	ring->signal_mbox[BCS] = GEN6_BVESYNC;
 	ring->signal_mbox[VECS] = GEN6_NOSYNC;
+	ring->signal_mbox[VCS2] = GEN6_NOSYNC;
 	ring->init = init_ring_common;
 
 	return intel_init_ring_buffer(dev, ring);

drivers/gpu/drm/i915/intel_ringbuffer.h

@@ -61,8 +61,9 @@ struct  intel_ring_buffer {
 		VCS,
 		BCS,
 		VECS,
+		VCS2
 	} id;
-#define I915_NUM_RINGS 4
+#define I915_NUM_RINGS 5
 #define LAST_USER_RING (VECS + 1)
 	u32		mmio_base;
 	void		__iomem *virtual_start;
@@ -288,6 +289,7 @@ int intel_ring_invalidate_all_caches(struct intel_ring_buffer *ring);
 
 int intel_init_render_ring_buffer(struct drm_device *dev);
 int intel_init_bsd_ring_buffer(struct drm_device *dev);
+int intel_init_bsd2_ring_buffer(struct drm_device *dev);
 int intel_init_blt_ring_buffer(struct drm_device *dev);
 int intel_init_vebox_ring_buffer(struct drm_device *dev);