[PATCH 12/13] drm/i915: semaphore debugfs

Ben Widawsky
2014-02-20T06:19:37Z

Simple debugfs file to display the current state of semaphores. This is
useful if you want to see the state without hanging the GPU.

NOTE: This patch is optional to the series.

NOTE2: Like the GPU error state collection, the reads are currently
incoherent.

Signed-off-by: Ben Widawsky <ben@bwidawsk.net>
---
drivers/gpu/drm/i915/i915_debugfs.c | 70 +++++++++++++++++++++++++++++++++++++
1 file changed, 70 insertions(+)

diff --git a/drivers/gpu/drm/i915/i915_debugfs.c b/drivers/gpu/drm/i915/i915_debugfs.c
index d90a707..6f3ecb6 100644
--- a/drivers/gpu/drm/i915/i915_debugfs.c
+++ b/drivers/gpu/drm/i915/i915_debugfs.c
@@ -2235,6 +2235,75 @@ static int i915_display_info(struct seq_file *m, void *unused)
return 0;
}

+static int i915_semaphore_status(struct seq_file *m, void *unused)
+{
+ struct drm_info_node *node = (struct drm_info_node *) m->private;
+ struct drm_device *dev = node->minor->dev;
+ struct drm_i915_private *dev_priv = dev->dev_private;
+ struct intel_ring_buffer *ring;
+ int i, j, ret;
+
+ if (!i915_semaphore_is_enabled(dev)) {
+ seq_puts(m, "Semaphores are disabled\n");
+ return 0;
+ }
+
+ ret = mutex_lock_interruptible(&dev->struct_mutex);
+ if (ret)
+ return ret;
+
+ if (IS_BROADWELL(dev)) {
+ struct page *page;
+ uint64_t *seqno;
+
+ page = i915_gem_object_get_page(dev_priv->semaphore_obj, 0);
+
+ seqno = (uint64_t *)kmap_atomic(page);
+ for_each_ring(ring, dev_priv, i) {
+ uint64_t offset;
+
+ seq_printf(m, "%s\n", ring->name);
+
+ seq_puts(m, " Last signal:");
+ for (j = 0; j < I915_NUM_RINGS; j++) {
+ offset = i * I915_NUM_RINGS + j;
+ seq_printf(m, "0x%08llx (0x%02llx) ",
+ seqno[offset], offset * 8);
+ }
+ seq_putc(m, '\n');
+
+ seq_puts(m, " Last wait: ");
+ for (j = 0; j < I915_NUM_RINGS; j++) {
+ offset = i + (j * I915_NUM_RINGS);
+ seq_printf(m, "0x%08llx (0x%02llx) ",
+ seqno[offset], offset * 8);
+ }
+ seq_putc(m, '\n');
+
+ }
+ kunmap_atomic(seqno);
+ } else {
+ seq_puts(m, " Last signal:");
+ for_each_ring(ring, dev_priv, i)
+ for (j = 0; j < I915_NUM_RINGS; j++)
+ seq_printf(m, "0x%08x\n",
+ I915_READ(ring->semaphore.mbox.signal[j]));
+ seq_putc(m, '\n');
+ }
+
+ seq_puts(m, "\nSync seqno:\n");
+ for_each_ring(ring, dev_priv, i) {
+ for (j = 0; j < I915_NUM_RINGS; j++) {
+ seq_printf(m, " 0x%08x ", ring->semaphore.sync_seqno[j]);
+ }
+ seq_putc(m, '\n');
+ }
+ seq_putc(m, '\n');
+
+ mutex_unlock(&dev->struct_mutex);
+ return 0;
+}
+
struct pipe_crc_info {
const char *name;
struct drm_device *dev;
@@ -3681,6 +3750,7 @@ static const struct drm_info_list i915_debugfs_list[] = {
{"i915_pc8_status", i915_pc8_status, 0},
{"i915_power_domain_info", i915_power_domain_info, 0},
{"i915_display_info", i915_display_info, 0},
+ {"i915_semaphore_status", i915_semaphore_status, 0},
};
#define I915_DEBUGFS_ENTRIES ARRAY_SIZE(i915_debugfs_list)

--
1.9.0