[RFC PATCH 03/42] drm/i915/guc: Connect the number of guc_ids to debugfs

[Matthew Brost <matthew.brost@xxxxxxxxx>]

For testing purposes it may make sense to reduce the number of guc_ids
available to be allocated. Add debugfs support for setting the number of
guc_ids.

Signed-off-by: Matthew Brost <matthew.brost@xxxxxxxxx>
---
 .../gpu/drm/i915/gt/uc/intel_guc_debugfs.c    | 31 +++++++++++++++++++
 .../gpu/drm/i915/gt/uc/intel_guc_submission.c |  3 +-
 2 files changed, 33 insertions(+), 1 deletion(-)

diff --git a/drivers/gpu/drm/i915/gt/uc/intel_guc_debugfs.c b/drivers/gpu/drm/i915/gt/uc/intel_guc_debugfs.c
index 72ddfff42f7d..7c479c5e7b3a 100644
--- a/drivers/gpu/drm/i915/gt/uc/intel_guc_debugfs.c
+++ b/drivers/gpu/drm/i915/gt/uc/intel_guc_debugfs.c
@@ -50,11 +50,42 @@ static int guc_registered_contexts_show(struct seq_file *m, void *data)
 }
 DEFINE_GT_DEBUGFS_ATTRIBUTE(guc_registered_contexts);
 
+static int guc_num_id_get(void *data, u64 *val)
+{
+	struct intel_guc *guc = data;
+
+	if (!intel_guc_submission_is_used(guc))
+		return -ENODEV;
+
+	*val = guc->num_guc_ids;
+
+	return 0;
+}
+
+static int guc_num_id_set(void *data, u64 val)
+{
+	struct intel_guc *guc = data;
+
+	if (!intel_guc_submission_is_used(guc))
+		return -ENODEV;
+
+	if (val > guc->max_guc_ids)
+		val = guc->max_guc_ids;
+	else if (val < 256)
+		val = 256;
+
+	guc->num_guc_ids = val;
+
+	return 0;
+}
+DEFINE_SIMPLE_ATTRIBUTE(guc_num_id_fops, guc_num_id_get, guc_num_id_set, "%lld\n");
+
 void intel_guc_debugfs_register(struct intel_guc *guc, struct dentry *root)
 {
 	static const struct debugfs_gt_file files[] = {
 		{ "guc_info", &guc_info_fops, NULL },
 		{ "guc_registered_contexts", &guc_registered_contexts_fops, NULL },
+		{ "guc_num_id", &guc_num_id_fops, NULL },
 	};
 
 	if (!intel_guc_is_supported(guc))
diff --git a/drivers/gpu/drm/i915/gt/uc/intel_guc_submission.c b/drivers/gpu/drm/i915/gt/uc/intel_guc_submission.c
index 46a149d447e6..c6069fe2f23c 100644
--- a/drivers/gpu/drm/i915/gt/uc/intel_guc_submission.c
+++ b/drivers/gpu/drm/i915/gt/uc/intel_guc_submission.c
@@ -2540,7 +2540,8 @@ g2h_context_lookup(struct intel_guc *guc, u32 desc_idx)
 
 	if (unlikely(desc_idx >= guc->max_guc_ids)) {
 		drm_err(&guc_to_gt(guc)->i915->drm,
-			"Invalid desc_idx %u", desc_idx);
+			"Invalid desc_idx %u, max %u",
+			desc_idx, guc->max_guc_ids);
 		return NULL;
 	}
 
-- 
2.28.0