drm/i915: Record DERRMR, FORCEWAKE and RING_CTL in error-state

These are useful for investigating hangs involving WAIT_FOR_EVENT.
Signed-off-by: NChris Wilson <chris@chris-wilson.co.uk>
[danvet: Apply a droplet of Future-Proof in the if-ladder.]
Signed-off-by: NDaniel Vetter <daniel.vetter@ffwll.ch>

drivers/gpu/drm/i915/i915_debugfs.c

@@ -641,6 +641,7 @@ static void i915_ring_error_state(struct seq_file *m,
 	seq_printf(m, "%s command stream:\n", ring_str(ring));
 	seq_printf(m, "  HEAD: 0x%08x\n", error->head[ring]);
 	seq_printf(m, "  TAIL: 0x%08x\n", error->tail[ring]);
+	seq_printf(m, "  CTL: 0x%08x\n", error->ctl[ring]);
 	seq_printf(m, "  ACTHD: 0x%08x\n", error->acthd[ring]);
 	seq_printf(m, "  IPEIR: 0x%08x\n", error->ipeir[ring]);
 	seq_printf(m, "  IPEHR: 0x%08x\n", error->ipehr[ring]);
@@ -693,6 +694,8 @@ static int i915_error_state(struct seq_file *m, void *unused)
 	seq_printf(m, "EIR: 0x%08x\n", error->eir);
 	seq_printf(m, "IER: 0x%08x\n", error->ier);
 	seq_printf(m, "PGTBL_ER: 0x%08x\n", error->pgtbl_er);
+	seq_printf(m, "FORCEWAKE: 0x%08x\n", error->forcewake);
+	seq_printf(m, "DERRMR: 0x%08x\n", error->derrmr);
 	seq_printf(m, "CCID: 0x%08x\n", error->ccid);
 
 	for (i = 0; i < dev_priv->num_fence_regs; i++)

drivers/gpu/drm/i915/i915_drv.h

@@ -188,10 +188,13 @@ struct drm_i915_error_state {
 	u32 pgtbl_er;
 	u32 ier;
 	u32 ccid;
+	u32 derrmr;
+	u32 forcewake;
 	bool waiting[I915_NUM_RINGS];
 	u32 pipestat[I915_MAX_PIPES];
 	u32 tail[I915_NUM_RINGS];
 	u32 head[I915_NUM_RINGS];
+	u32 ctl[I915_NUM_RINGS];
 	u32 ipeir[I915_NUM_RINGS];
 	u32 ipehr[I915_NUM_RINGS];
 	u32 instdone[I915_NUM_RINGS];

drivers/gpu/drm/i915/i915_irq.c

@@ -1157,6 +1157,7 @@ static void i915_record_ring_state(struct drm_device *dev,
 	error->acthd[ring->id] = intel_ring_get_active_head(ring);
 	error->head[ring->id] = I915_READ_HEAD(ring);
 	error->tail[ring->id] = I915_READ_TAIL(ring);
+	error->ctl[ring->id] = I915_READ_CTL(ring);
 
 	error->cpu_ring_head[ring->id] = ring->head;
 	error->cpu_ring_tail[ring->id] = ring->tail;
@@ -1251,6 +1252,16 @@ static void i915_capture_error_state(struct drm_device *dev)
 	else
 		error->ier = I915_READ(IER);
 
+	if (INTEL_INFO(dev)->gen >= 6)
+		error->derrmr = I915_READ(DERRMR);
+
+	if (IS_VALLEYVIEW(dev))
+		error->forcewake = I915_READ(FORCEWAKE_VLV);
+	else if (INTEL_INFO(dev)->gen >= 7)
+		error->forcewake = I915_READ(FORCEWAKE_MT);
+	else if (INTEL_INFO(dev)->gen == 6)
+		error->forcewake = I915_READ(FORCEWAKE);
+
 	for_each_pipe(pipe)
 		error->pipestat[pipe] = I915_READ(PIPESTAT(pipe));
 

drivers/gpu/drm/i915/i915_reg.h

@@ -512,6 +512,8 @@
 #define GEN7_ERR_INT	0x44040
 #define   ERR_INT_MMIO_UNCLAIMED (1<<13)
 
+#define DERRMR		0x44050
+
 /* GM45+ chicken bits -- debug workaround bits that may be required
  * for various sorts of correct behavior.  The top 16 bits of each are
  * the enables for writing to the corresponding low bit.