Using a new "debug_flags" we'll be able to configure some options which
make it easier for user space to quickly identify when there is a bug in
their code.
There is no way to yet turn it on.
Signed-off-by: Ben Widawsky <ben at bwidawsk.net>
---
drivers/gpu/drm/i915/i915_debugfs.c | 1 +
drivers/gpu/drm/i915/i915_drv.c | 3 +++
drivers/gpu/drm/i915/i915_drv.h | 4 ++++
drivers/gpu/drm/i915/i915_gem_gtt.c | 9 +++++++++
4 files changed, 17 insertions(+)
diff --git a/drivers/gpu/drm/i915/i915_debugfs.c b/drivers/gpu/drm/i915/i915_debugfs.c
index b3a2dbe..4d9d8a1 100644
--- a/drivers/gpu/drm/i915/i915_debugfs.c
+++ b/drivers/gpu/drm/i915/i915_debugfs.c
@@ -812,6 +812,7 @@ static int i915_error_state(struct i915_error_state_file_priv *error_priv,
err_printf(m, "FORCEWAKE: 0x%08x\n", error->forcewake);
err_printf(m, "DERRMR: 0x%08x\n", error->derrmr);
err_printf(m, "CCID: 0x%08x\n", error->ccid);
+ err_printf(m, "debug_flags: 0x%llx\n", dev_priv->debug_flags);
for (i = 0; i < dev_priv->num_fence_regs; i++)
err_printf(m, " fence[%d] = %08llx\n", i, error->fence[i]);
diff --git a/drivers/gpu/drm/i915/i915_drv.c b/drivers/gpu/drm/i915/i915_drv.c
index 062cbda..5718f45 100644
--- a/drivers/gpu/drm/i915/i915_drv.c
+++ b/drivers/gpu/drm/i915/i915_drv.c
@@ -940,6 +940,9 @@ int i915_reset(struct drm_device *dev)
return ret;
}
+ /* Assume debug flags may have been the cause of the problem */
+ dev_priv->debug_flags = 0;
+
/* Ok, now get things going again... */
/*
diff --git a/drivers/gpu/drm/i915/i915_drv.h b/drivers/gpu/drm/i915/i915_drv.h
index 56bd82b..7a98f7e 100644
--- a/drivers/gpu/drm/i915/i915_drv.h
+++ b/drivers/gpu/drm/i915/i915_drv.h
@@ -1176,6 +1176,10 @@ typedef struct drm_i915_private {
/* Old dri1 support infrastructure, beware the dragons ya fools entering
* here! */
struct i915_dri1_state dri1;
+
+#define I915_DEBUG_NONE 0
+#define I915_SCRATCH_FAULTS (1<<0)
+ u64 debug_flags;
} drm_i915_private_t;
/* Iterate over initialised rings */
diff --git a/drivers/gpu/drm/i915/i915_gem_gtt.c b/drivers/gpu/drm/i915/i915_gem_gtt.c
index 5101ab6..982c791 100644
--- a/drivers/gpu/drm/i915/i915_gem_gtt.c
+++ b/drivers/gpu/drm/i915/i915_gem_gtt.c
@@ -41,6 +41,8 @@
#define GEN6_PTE_CACHE_LLC (2 << 1)
#define GEN6_PTE_CACHE_LLC_MLC (3 << 1)
#define GEN6_PTE_ADDR_ENCODE(addr) GEN6_GTT_ADDR_ENCODE(addr)
+/* Use a pattern to make debug a bit easier */
+#define GEN6_PTE_FAULT 0xbaddc0de
static gen6_gtt_pte_t gen6_pte_encode(struct drm_device *dev,
dma_addr_t addr,
@@ -185,6 +187,7 @@ static void gen6_ppgtt_clear_range(struct i915_hw_ppgtt *ppgtt,
unsigned first_entry,
unsigned num_entries)
{
+ struct drm_i915_private *dev_priv = ppgtt->dev->dev_private;
gen6_gtt_pte_t *pt_vaddr, scratch_pte;
unsigned act_pt = first_entry / I915_PPGTT_PT_ENTRIES;
unsigned first_pte = first_entry % I915_PPGTT_PT_ENTRIES;
@@ -194,6 +197,9 @@ static void gen6_ppgtt_clear_range(struct i915_hw_ppgtt *ppgtt,
ppgtt->scratch_page_dma_addr,
I915_CACHE_LLC);
+ if (unlikely(dev_priv->debug_flags & I915_SCRATCH_FAULTS))
+ scratch_pte = GEN6_PTE_FAULT;
+
while (num_entries) {
last_pte = first_pte + num_entries;
if (last_pte > I915_PPGTT_PT_ENTRIES)
@@ -521,6 +527,8 @@ static void gen6_ggtt_clear_range(struct drm_device *dev,
scratch_pte = dev_priv->gtt.pte_encode(dev,
dev_priv->gtt.scratch_page_dma,
I915_CACHE_LLC);
+ if (unlikely(dev_priv->debug_flags & I915_SCRATCH_FAULTS))
+ scratch_pte = GEN6_PTE_FAULT;
for (i = 0; i < num_entries; i++)
iowrite32(scratch_pte, >t_base[i]);
readl(gtt_base);
@@ -623,6 +631,7 @@ void i915_gem_setup_global_gtt(struct drm_device *dev,
struct drm_i915_gem_object *obj;
unsigned long hole_start, hole_end;
+ BUILD_BUG_ON(GEN6_PTE_FAULT & GEN6_PTE_VALID);
BUG_ON(mappable_end > end);
/* Subtract the guard page ... */
--
1.8.3.1
