drm/i915/bdw: Implement interrupt changes

The interrupt handling implementation remains the same as previous
generations with the 4 types of registers, status, identity, mask, and
enable. However the layout of where the bits go have changed entirely.
To address these changes, all of the interrupt vfuncs needed special
gen8 code.

The way it works is there is a top level status register now which
informs the interrupt service routine which unit caused the interrupt,
and therefore which interrupt registers to read to process the
interrupt. For display the division is quite logical, a set of interrupt
registers for each pipe, and in addition to those, a set each for "misc"
and port.

For GT the things get a bit hairy, as seen by the code. Each of the GT
units has it's own bits defined. They all look *very similar* and
resides in 16 bits of a GT register. As an example, RCS and BCS share
register 0. To compact the code a bit, at a slight expense to
complexity, this is exactly how the code works as well. 2 structures are
added to the ring buffer so that our ring buffer interrupt handling code
knows which ring shares the interrupt registers, and a shift value (ie.
the top or bottom 16 bits of the register).

The above allows us to kept the interrupt register caching scheme, the
per interrupt enables, and the code to mask and unmask interrupts
relatively clean (again at the cost of some more complexity).

Most of the GT units mentioned above are command streamers, and so the
symmetry should work quite well for even the yet to be implemented rings
which Broadwell adds.

v2: Fixes up a couple of bugs, and is more verbose about errors in the
Broadwell interrupt handler.

v3: fix DE_MISC IER offset

v4: Simplify interrupts:
I totally misread the docs the first time I implemented interrupts, and
so this should greatly simplify the mess. Unlike GEN6, we never touch
the regular mask registers in irq_get/put.

v5: Rebased on to of recent pch hotplug setup changes.

v6: Fixup on top of moving num_pipes to intel_info.

v7: Rebased on top of Egbert Eich's hpd irq handling rework. Also
wired up ibx_hpd_irq_setup for gen8.

v8: Rebase on top of Jani's asle handling rework.

v9: Rebase on top of Ben's VECS enabling for Haswell, where he
unfortunately went OCD on the gt irq #defines. Not that they're still
not yet fully consistent:
- Used the GT_RENDER_ #defines + bdw shifts.
- Dropped the shift from the L3_PARITY stuff, seemed clearer.
- s/irq_refcount/irq_refcount.gt/

v10: Squash in VECS enabling patches and the gen8_gt_irq_handler
refactoring from Zhao Yakui <yakui.zhao@intel.com>

v11: Rebase on top of the interrupt cleanups in upstream.

v12: Rebase on top of Ben's DPF changes in upstream.

v13: Drop bdw from the HAS_L3_DPF feature flag for now, it's unclear what
exactly needs to be done. Requested by Ben.

v14: Fix the patch.
- Drop the mask of reserved bits and assorted logic, it doesn't match
  the spec.
- Do the posting read inconditionally instead of commenting it out.
- Add a GEN8_MASTER_IRQ_CONTROL definition and use it.
- Fix up the GEN8_PIPE interrupt defines and give the GEN8_ prefixes -
  we actually will need to use them.
- Enclose macros in do {} while (0) (checkpatch).
- Clear DE_MISC interrupt bits only after having processed them.
- Fix whitespace fail (checkpatch).
- Fix overtly long lines where appropriate (checkpatch).
- Don't use typedef'ed private_t (maintainer-scripts).
- Align the function parameter list correctly.

Signed-off-by: Ben Widawsky <ben@bwidawsk.net> (v4)
Signed-off-by: Daniel Vetter <daniel.vetter@ffwll.ch>

bikeshed

drivers/gpu/drm/i915/i915_drv.h

@@ -1317,7 +1317,10 @@ typedef struct drm_i915_private {
 	struct mutex dpio_lock;
 
 	/** Cached value of IMR to avoid reads in updating the bitfield */
-	u32 irq_mask;
+	union {
+		u32 irq_mask;
+		u32 de_irq_mask[I915_MAX_PIPES];
+	};
 	u32 gt_irq_mask;
 	u32 pm_irq_mask;
 

drivers/gpu/drm/i915/i915_reg.h

@@ -4002,6 +4002,74 @@
 #define GTIIR   0x44018
 #define GTIER   0x4401c
 
+#define GEN8_MASTER_IRQ			0x44200
+#define  GEN8_MASTER_IRQ_CONTROL	(1<<31)
+#define  GEN8_PCU_IRQ			(1<<30)
+#define  GEN8_DE_PCH_IRQ		(1<<23)
+#define  GEN8_DE_MISC_IRQ		(1<<22)
+#define  GEN8_DE_PORT_IRQ		(1<<20)
+#define  GEN8_DE_PIPE_C_IRQ		(1<<18)
+#define  GEN8_DE_PIPE_B_IRQ		(1<<17)
+#define  GEN8_DE_PIPE_A_IRQ		(1<<16)
+#define  GEN8_GT_VECS_IRQ		(1<<6)
+#define  GEN8_GT_VCS2_IRQ		(1<<3)
+#define  GEN8_GT_VCS1_IRQ		(1<<2)
+#define  GEN8_GT_BCS_IRQ		(1<<1)
+#define  GEN8_GT_RCS_IRQ		(1<<0)
+/* Lazy definition */
+#define  GEN8_GT_IRQS			0x000000ff
+#define  GEN8_DE_IRQS			0x01ff0000
+#define  GEN8_RSVD_IRQS			0xB700ff00
+
+#define GEN8_GT_ISR(which) (0x44300 + (0x10 * (which)))
+#define GEN8_GT_IMR(which) (0x44304 + (0x10 * (which)))
+#define GEN8_GT_IIR(which) (0x44308 + (0x10 * (which)))
+#define GEN8_GT_IER(which) (0x4430c + (0x10 * (which)))
+
+#define GEN8_BCS_IRQ_SHIFT 16
+#define GEN8_RCS_IRQ_SHIFT 0
+#define GEN8_VCS2_IRQ_SHIFT 16
+#define GEN8_VCS1_IRQ_SHIFT 0
+#define GEN8_VECS_IRQ_SHIFT 0
+
+#define GEN8_DE_PIPE_ISR(pipe) (0x44400 + (0x10 * (pipe)))
+#define GEN8_DE_PIPE_IMR(pipe) (0x44404 + (0x10 * (pipe)))
+#define GEN8_DE_PIPE_IIR(pipe) (0x44408 + (0x10 * (pipe)))
+#define GEN8_DE_PIPE_IER(pipe) (0x4440c + (0x10 * (pipe)))
+#define  GEN8_PIPE_UNDERRUN		(1 << 31)
+#define  GEN8_PIPE_CDCLK_CRC_ERROR	(1 << 29)
+#define  GEN8_PIPE_CDCLK_CRC_DONE	(1 << 28)
+#define  GEN8_PIPE_CURSOR_FAULT		(1 << 10)
+#define  GEN8_PIPE_SPRITE_FAULT		(1 << 9)
+#define  GEN8_PIPE_PRIMARY_FAULT	(1 << 8)
+#define  GEN8_PIPE_SPRITE_FLIP_DONE	(1 << 5)
+#define  GEN8_PIPE_FLIP_DONE		(1 << 4)
+#define  GEN8_PIPE_SCAN_LINE_EVENT	(1 << 2)
+#define  GEN8_PIPE_VSYNC		(1 << 1)
+#define  GEN8_PIPE_VBLANK		(1 << 0)
+#define GEN8_DE_PIPE_IRQ_ERRORS	(GEN8_PIPE_UNDERRUN | \
+				 GEN8_PIPE_CDCLK_CRC_ERROR | \
+				 GEN8_PIPE_CURSOR_FAULT | \
+				 GEN8_PIPE_SPRITE_FAULT | \
+				 GEN8_PIPE_PRIMARY_FAULT)
+
+#define GEN8_DE_PORT_ISR 0x44440
+#define GEN8_DE_PORT_IMR 0x44444
+#define GEN8_DE_PORT_IIR 0x44448
+#define GEN8_DE_PORT_IER 0x4444c
+#define  _PORT_DP_A_HOTPLUG		(1 << 3)
+
+#define GEN8_DE_MISC_ISR 0x44460
+#define GEN8_DE_MISC_IMR 0x44464
+#define GEN8_DE_MISC_IIR 0x44468
+#define GEN8_DE_MISC_IER 0x4446c
+#define  GEN8_DE_MISC_GSE		(1 << 27)
+
+#define GEN8_PCU_ISR 0x444e0
+#define GEN8_PCU_IMR 0x444e4
+#define GEN8_PCU_IIR 0x444e8
+#define GEN8_PCU_IER 0x444ec
+
 #define ILK_DISPLAY_CHICKEN2	0x42004
 /* Required on all Ironlake and Sandybridge according to the B-Spec. */
 #define  ILK_ELPIN_409_SELECT	(1 << 25)

drivers/gpu/drm/i915/intel_ringbuffer.c

@@ -1066,6 +1066,52 @@ hsw_vebox_put_irq(struct intel_ring_buffer *ring)
 	spin_unlock_irqrestore(&dev_priv->irq_lock, flags);
 }
 
+static bool
+gen8_ring_get_irq(struct intel_ring_buffer *ring)
+{
+	struct drm_device *dev = ring->dev;
+	struct drm_i915_private *dev_priv = dev->dev_private;
+	unsigned long flags;
+
+	if (!dev->irq_enabled)
+		return false;
+
+	spin_lock_irqsave(&dev_priv->irq_lock, flags);
+	if (ring->irq_refcount++ == 0) {
+		if (HAS_L3_DPF(dev) && ring->id == RCS) {
+			I915_WRITE_IMR(ring,
+				       ~(ring->irq_enable_mask |
+					 GT_RENDER_L3_PARITY_ERROR_INTERRUPT));
+		} else {
+			I915_WRITE_IMR(ring, ~ring->irq_enable_mask);
+		}
+		POSTING_READ(RING_IMR(ring->mmio_base));
+	}
+	spin_unlock_irqrestore(&dev_priv->irq_lock, flags);
+
+	return true;
+}
+
+static void
+gen8_ring_put_irq(struct intel_ring_buffer *ring)
+{
+	struct drm_device *dev = ring->dev;
+	struct drm_i915_private *dev_priv = dev->dev_private;
+	unsigned long flags;
+
+	spin_lock_irqsave(&dev_priv->irq_lock, flags);
+	if (--ring->irq_refcount == 0) {
+		if (HAS_L3_DPF(dev) && ring->id == RCS) {
+			I915_WRITE_IMR(ring,
+				       ~GT_RENDER_L3_PARITY_ERROR_INTERRUPT);
+		} else {
+			I915_WRITE_IMR(ring, ~0);
+		}
+		POSTING_READ(RING_IMR(ring->mmio_base));
+	}
+	spin_unlock_irqrestore(&dev_priv->irq_lock, flags);
+}
+
 static int
 i965_dispatch_execbuffer(struct intel_ring_buffer *ring,
 			 u32 offset, u32 length,
@@ -1732,8 +1778,13 @@ int intel_init_render_ring_buffer(struct drm_device *dev)
 		ring->flush = gen7_render_ring_flush;
 		if (INTEL_INFO(dev)->gen == 6)
 			ring->flush = gen6_render_ring_flush;
-		ring->irq_get = gen6_ring_get_irq;
-		ring->irq_put = gen6_ring_put_irq;
+		if (INTEL_INFO(dev)->gen >= 8) {
+			ring->irq_get = gen8_ring_get_irq;
+			ring->irq_put = gen8_ring_put_irq;
+		} else {
+			ring->irq_get = gen6_ring_get_irq;
+			ring->irq_put = gen6_ring_put_irq;
+		}
 		ring->irq_enable_mask = GT_RENDER_USER_INTERRUPT;
 		ring->get_seqno = gen6_ring_get_seqno;
 		ring->set_seqno = ring_set_seqno;
@@ -1897,9 +1948,16 @@ int intel_init_bsd_ring_buffer(struct drm_device *dev)
 		ring->add_request = gen6_add_request;
 		ring->get_seqno = gen6_ring_get_seqno;
 		ring->set_seqno = ring_set_seqno;
-		ring->irq_enable_mask = GT_BSD_USER_INTERRUPT;
-		ring->irq_get = gen6_ring_get_irq;
-		ring->irq_put = gen6_ring_put_irq;
+		if (INTEL_INFO(dev)->gen >= 8) {
+			ring->irq_enable_mask =
+				GT_RENDER_USER_INTERRUPT << GEN8_VCS1_IRQ_SHIFT;
+			ring->irq_get = gen8_ring_get_irq;
+			ring->irq_put = gen8_ring_put_irq;
+		} else {
+			ring->irq_enable_mask = GT_BSD_USER_INTERRUPT;
+			ring->irq_get = gen6_ring_get_irq;
+			ring->irq_put = gen6_ring_put_irq;
+		}
 		ring->dispatch_execbuffer = gen6_ring_dispatch_execbuffer;
 		ring->sync_to = gen6_ring_sync;
 		ring->semaphore_register[RCS] = MI_SEMAPHORE_SYNC_VR;
@@ -1946,9 +2004,16 @@ int intel_init_blt_ring_buffer(struct drm_device *dev)
 	ring->add_request = gen6_add_request;
 	ring->get_seqno = gen6_ring_get_seqno;
 	ring->set_seqno = ring_set_seqno;
-	ring->irq_enable_mask = GT_BLT_USER_INTERRUPT;
-	ring->irq_get = gen6_ring_get_irq;
-	ring->irq_put = gen6_ring_put_irq;
+	if (INTEL_INFO(dev)->gen >= 8) {
+		ring->irq_enable_mask =
+			GT_RENDER_USER_INTERRUPT << GEN8_BCS_IRQ_SHIFT;
+		ring->irq_get = gen8_ring_get_irq;
+		ring->irq_put = gen8_ring_put_irq;
+	} else {
+		ring->irq_enable_mask = GT_BLT_USER_INTERRUPT;
+		ring->irq_get = gen6_ring_get_irq;
+		ring->irq_put = gen6_ring_put_irq;
+	}
 	ring->dispatch_execbuffer = gen6_ring_dispatch_execbuffer;
 	ring->sync_to = gen6_ring_sync;
 	ring->semaphore_register[RCS] = MI_SEMAPHORE_SYNC_BR;
@@ -1978,10 +2043,19 @@ int intel_init_vebox_ring_buffer(struct drm_device *dev)
 	ring->add_request = gen6_add_request;
 	ring->get_seqno = gen6_ring_get_seqno;
 	ring->set_seqno = ring_set_seqno;
-	ring->irq_enable_mask = PM_VEBOX_USER_INTERRUPT;
-	ring->irq_get = hsw_vebox_get_irq;
-	ring->irq_put = hsw_vebox_put_irq;
 	ring->dispatch_execbuffer = gen6_ring_dispatch_execbuffer;
+
+	if (INTEL_INFO(dev)->gen >= 8) {
+		ring->irq_enable_mask =
+			(GT_RENDER_USER_INTERRUPT << GEN8_VECS_IRQ_SHIFT) |
+			GT_RENDER_CS_MASTER_ERROR_INTERRUPT;
+		ring->irq_get = gen8_ring_get_irq;
+		ring->irq_put = gen8_ring_put_irq;
+	} else {
+		ring->irq_enable_mask = PM_VEBOX_USER_INTERRUPT;
+		ring->irq_get = hsw_vebox_get_irq;
+		ring->irq_put = hsw_vebox_put_irq;
+	}
 	ring->sync_to = gen6_ring_sync;
 	ring->semaphore_register[RCS] = MI_SEMAPHORE_SYNC_VER;
 	ring->semaphore_register[VCS] = MI_SEMAPHORE_SYNC_VEV;