drm/i915: Implement batch and ring buffer dumping

We create a debugfs node (i915_ringbuffer_data) to expose a hex dump
of the ring buffer itself.  We also expose another debugfs node
(i915_ringbuffer_info) with information on the state (i.e. head, tail
addresses) of the ringbuffer.

For batchbuffer dumping, we look at the device's active_list, dumping
each object which has I915_GEM_DOMAIN_COMMAND in its read
domains. This is all exposed through the dri/i915_batchbuffers debugfs
file with a header for each object (giving the objects gtt_offset so
that it can be matched against the offset given in the
BATCH_BUFFER_START command.

Signed-off-by: Ben Gamari <bgamari@gmail.com>
Signed-off-by: Carl Worth <cworth@cworth.org>
Signed-off-by: Eric Anholt <eric@anholt.net>

1 files changed, 93 insertions, 0 deletions

diff --git a/drivers/gpu/drm/i915/i915_gem_debugfs.c b/drivers/gpu/drm/i915/i915_gem_debugfs.c
index a1ac0c5e730..986f1082c59 100644
--- a/drivers/gpu/drm/i915/i915_gem_debugfs.c
+++ b/drivers/gpu/drm/i915/i915_gem_debugfs.c
@@ -234,6 +234,96 @@ static int i915_hws_info(struct seq_file *m, void *data)
         return 0;
 }
 
+static void i915_dump_pages(struct seq_file *m, struct page **pages, int page_count)
+{
+        int page, i;
+        uint32_t *mem;
+
+        for (page = 0; page < page_count; page++) {
+                mem = kmap(pages[page]);
+                for (i = 0; i < PAGE_SIZE; i += 4)
+                        seq_printf(m, "%08x :  %08x\n", i, mem[i / 4]);
+                kunmap(pages[page]);
+        }
+}
+
+static int i915_batchbuffer_info(struct seq_file *m, void *data)
+{
+        struct drm_info_node *node = (struct drm_info_node *) m->private;
+        struct drm_device *dev = node->minor->dev;
+        drm_i915_private_t *dev_priv = dev->dev_private;
+        struct drm_gem_object *obj;
+        struct drm_i915_gem_object *obj_priv;
+        int ret;
+
+        spin_lock(&dev_priv->mm.active_list_lock);
+
+        list_for_each_entry(obj_priv, &dev_priv->mm.active_list, list) {
+                obj = obj_priv->obj;
+                if (obj->read_domains & I915_GEM_DOMAIN_COMMAND) {
+                    ret = i915_gem_object_get_pages(obj);
+                    if (ret) {
+                            DRM_ERROR("Failed to get pages: %d\n", ret);
+                            spin_unlock(&dev_priv->mm.active_list_lock);
+                            return ret;
+                    }
+
+                    seq_printf(m, "--- gtt_offset = 0x%08x\n", obj_priv->gtt_offset);
+                    i915_dump_pages(m, obj_priv->pages, obj->size / PAGE_SIZE);
+
+                    i915_gem_object_put_pages(obj);
+                }
+        }
+
+        spin_unlock(&dev_priv->mm.active_list_lock);
+
+        return 0;
+}
+
+static int i915_ringbuffer_data(struct seq_file *m, void *data)
+{
+        struct drm_info_node *node = (struct drm_info_node *) m->private;
+        struct drm_device *dev = node->minor->dev;
+        drm_i915_private_t *dev_priv = dev->dev_private;
+        u8 *virt;
+        uint32_t *ptr, off;
+
+        if (!dev_priv->ring.ring_obj) {
+                seq_printf(m, "No ringbuffer setup\n");
+                return 0;
+        }
+
+        virt = dev_priv->ring.virtual_start;
+
+        for (off = 0; off < dev_priv->ring.Size; off += 4) {
+                ptr = (uint32_t *)(virt + off);
+                seq_printf(m, "%08x :  %08x\n", off, *ptr);
+        }
+
+        return 0;
+}
+
+static int i915_ringbuffer_info(struct seq_file *m, void *data)
+{
+        struct drm_info_node *node = (struct drm_info_node *) m->private;
+        struct drm_device *dev = node->minor->dev;
+        drm_i915_private_t *dev_priv = dev->dev_private;
+        unsigned int head, tail, mask;
+
+        head = I915_READ(PRB0_HEAD) & HEAD_ADDR;
+        tail = I915_READ(PRB0_TAIL) & TAIL_ADDR;
+        mask = dev_priv->ring.tail_mask;
+
+        seq_printf(m, "RingHead :  %08x\n", head);
+        seq_printf(m, "RingTail :  %08x\n", tail);
+        seq_printf(m, "RingMask :  %08x\n", mask);
+        seq_printf(m, "RingSize :  %08lx\n", dev_priv->ring.Size);
+        seq_printf(m, "Acthd :  %08x\n", I915_READ(IS_I965G(dev) ? ACTHD_I965 : ACTHD));
+
+        return 0;
+}
+
+
 static struct drm_info_list i915_gem_debugfs_list[] = {
         {"i915_gem_active", i915_gem_object_list_info, 0, (void *) ACTIVE_LIST},
         {"i915_gem_flushing", i915_gem_object_list_info, 0, (void *) FLUSHING_LIST},
@@ -243,6 +333,9 @@ static struct drm_info_list i915_gem_debugfs_list[] = {
         {"i915_gem_fence_regs", i915_gem_fence_regs_info, 0},
         {"i915_gem_interrupt", i915_interrupt_info, 0},
         {"i915_gem_hws", i915_hws_info, 0},
+        {"i915_ringbuffer_data", i915_ringbuffer_data, 0},
+        {"i915_ringbuffer_info", i915_ringbuffer_info, 0},
+        {"i915_batchbuffers", i915_batchbuffer_info, 0},
 };
 #define I915_GEM_DEBUGFS_ENTRIES ARRAY_SIZE(i915_gem_debugfs_list)