[PATCH 44/48] drm/i915: Add PPGTT dumper

Ben Widawsky
2013-12-06T22:15:57Z

From: Ben Widawsky <ben@bwidawsk.net>

Dump the aliasing PPGTT with it. The aliasing PPGTT should actually
always be empty.

TODO: Broadwell. Since we don't yet use full PPGTT on Broadwell, not
having the dumper is okay.

Signed-off-by: Ben Widawsky <ben@bwidawsk.net>

Conflicts:
drivers/gpu/drm/i915/i915_debugfs.c
drivers/gpu/drm/i915/i915_drv.h
drivers/gpu/drm/i915/i915_gem_gtt.c
---
drivers/gpu/drm/i915/i915_debugfs.c | 1 +
drivers/gpu/drm/i915/i915_drv.h | 1 +
drivers/gpu/drm/i915/i915_gem_gtt.c | 57 +++++++++++++++++++++++++++++++++++++
3 files changed, 59 insertions(+)

diff --git a/drivers/gpu/drm/i915/i915_debugfs.c b/drivers/gpu/drm/i915/i915_debugfs.c
index 4c610ee..6a98b64 100644
--- a/drivers/gpu/drm/i915/i915_debugfs.c
+++ b/drivers/gpu/drm/i915/i915_debugfs.c
@@ -1704,6 +1704,7 @@ static void gen6_ppgtt_info(struct seq_file *m, struct drm_device *dev)

seq_puts(m, "aliasing PPGTT:\n");
seq_printf(m, "pd gtt offset: 0x%08x\n", ppgtt->pd_offset);
+ ppgtt->debug_dump(ppgtt, m);
}
seq_printf(m, "ECOCHK: 0x%08x\n", I915_READ(GAM_ECOCHK));
}
diff --git a/drivers/gpu/drm/i915/i915_drv.h b/drivers/gpu/drm/i915/i915_drv.h
index f404491..718a986 100644
--- a/drivers/gpu/drm/i915/i915_drv.h
+++ b/drivers/gpu/drm/i915/i915_drv.h
@@ -677,6 +677,7 @@ struct i915_hw_ppgtt {
int (*switch_mm)(struct i915_hw_ppgtt *ppgtt,
struct intel_ring_buffer *ring,
bool synchronous);
+ void (*debug_dump)(struct i915_hw_ppgtt *ppgtt, struct seq_file *m);
};

struct i915_ctx_hang_stats {
diff --git a/drivers/gpu/drm/i915/i915_gem_gtt.c b/drivers/gpu/drm/i915/i915_gem_gtt.c
index ece9d8e..998f9a0 100644
--- a/drivers/gpu/drm/i915/i915_gem_gtt.c
+++ b/drivers/gpu/drm/i915/i915_gem_gtt.c
@@ -460,6 +460,62 @@ err_out:
return ret;
}

+static void gen6_dump_ppgtt(struct i915_hw_ppgtt *ppgtt, struct seq_file *m)
+{
+ struct drm_i915_private *dev_priv = ppgtt->base.dev->dev_private;
+ struct i915_address_space *vm = &ppgtt->base;
+ gen6_gtt_pte_t __iomem *pd_addr;
+ gen6_gtt_pte_t scratch_pte;
+ uint32_t pd_entry;
+ int pte, pde;
+
+ scratch_pte = vm->pte_encode(vm->scratch.addr, I915_CACHE_LLC, true);
+
+ pd_addr = (gen6_gtt_pte_t __iomem *)dev_priv->gtt.gsm +
+ ppgtt->pd_offset / sizeof(gen6_gtt_pte_t);
+
+ seq_printf(m, " VM %p (pd_offset %x-%x):\n", vm,
+ ppgtt->pd_offset, ppgtt->pd_offset + ppgtt->num_pd_entries);
+ for (pde = 0; pde < ppgtt->num_pd_entries; pde++) {
+ u32 expected;
+ gen6_gtt_pte_t *pt_vaddr;
+ dma_addr_t pt_addr = ppgtt->pt_dma_addr[pde];
+ pd_entry = readl(pd_addr + pde);
+ expected = (GEN6_PDE_ADDR_ENCODE(pt_addr) | GEN6_PDE_VALID);
+
+ if (pd_entry != expected)
+ seq_printf(m, "\tPDE #%d mismatch: Actual PDE: %x Expected PDE: %x\n",
+ pde,
+ pd_entry,
+ expected);
+ seq_printf(m, "\tPDE: %x\n", pd_entry);
+
+ pt_vaddr = kmap_atomic(ppgtt->pt_pages[pde]);
+ for (pte = 0; pte < I915_PPGTT_PT_ENTRIES; pte+=4) {
+ unsigned long va =
+ (pde * PAGE_SIZE * I915_PPGTT_PT_ENTRIES) +
+ (pte * PAGE_SIZE);
+ int i;
+ bool found = false;
+ for (i = 0; i < 4; i++)
+ if (pt_vaddr[pte + i] != scratch_pte)
+ found = true;
+ if (!found)
+ continue;
+
+ seq_printf(m, "\t\t0x%lx [%03d,%04d]: =", va, pde, pte);
+ for (i = 0; i < 4; i++) {
+ if (pt_vaddr[pte + i] != scratch_pte)
+ seq_printf(m, " %08x", pt_vaddr[pte + i]);
+ else
+ seq_puts(m, " SCRATCH ");
+ }
+ seq_puts(m, "\n");
+ }
+ kunmap_atomic(pt_vaddr);
+ }
+}
+
static void gen6_write_pdes(struct i915_hw_ppgtt *ppgtt)
{
struct drm_i915_private *dev_priv = ppgtt->base.dev->dev_private;
@@ -873,6 +929,7 @@ alloc:

ppgtt->base.clear_range(&ppgtt->base, 0,
ppgtt->num_pd_entries * I915_PPGTT_PT_ENTRIES, true);
+ ppgtt->debug_dump = gen6_dump_ppgtt;

DRM_DEBUG_DRIVER("Allocated pde space (%ldM) at GTT entry: %lx\n",
ppgtt->node.size >> 20,
--
1.8.4.2