Add capture output size check function to provide a reasonable
minimum size for error capture region before allocating the shared
buffer.
Signed-off-by: Zhanjun Dong <zhanjun.dong@xxxxxxxxx>
---
drivers/gpu/drm/xe/xe_guc_capture.c | 76 +++++++++++++++++++++++++++++
1 file changed, 76 insertions(+)
diff --git a/drivers/gpu/drm/xe/xe_guc_capture.c b/drivers/gpu/drm/xe/xe_guc_capture.c
index dde3a269d114..f4153dc4ab86 100644
--- a/drivers/gpu/drm/xe/xe_guc_capture.c
+++ b/drivers/gpu/drm/xe/xe_guc_capture.c
@@ -559,6 +559,81 @@ xe_guc_capture_getnullheader(struct xe_guc *guc, void **outptr, size_t *size)
return 0;
}
+static int
+guc_capture_output_min_size_est(struct xe_guc *guc)
+{
+ struct xe_gt *gt = guc_to_gt(guc);
+ struct xe_hw_engine *hwe;
+ enum xe_hw_engine_id id;
+
+ int worst_min_size = 0;
+ size_t tmp = 0;
+
+ if (!guc->capture)
+ return -ENODEV;
+
+ /*
+ * If every single engine-instance suffered a failure in quick succession but
+ * were all unrelated, then a burst of multiple error-capture events would dump
+ * registers for every one engine instance, one at a time. In this case, GuC
+ * would even dump the global-registers repeatedly.
+ *
+ * For each engine instance, there would be 1 x guc_state_capture_group_t output
+ * followed by 3 x guc_state_capture_t lists. The latter is how the register
+ * dumps are split across different register types (where the '3' are global vs class
+ * vs instance).
+ */
+ for_each_hw_engine(hwe, gt, id) {
+ worst_min_size += sizeof(struct guc_state_capture_group_header_t) +
+ (3 * sizeof(struct guc_state_capture_header_t));
+
+ if (!guc_capture_getlistsize(guc, 0, GUC_CAPTURE_LIST_TYPE_GLOBAL, 0, &tmp, true))
+ worst_min_size += tmp;
+
+ if (!guc_capture_getlistsize(guc, 0, GUC_CAPTURE_LIST_TYPE_ENGINE_CLASS,
+ hwe->class, &tmp, true)) {
+ worst_min_size += tmp;
+ }
+ if (!guc_capture_getlistsize(guc, 0, GUC_CAPTURE_LIST_TYPE_ENGINE_INSTANCE,
+ hwe->class, &tmp, true)) {
+ worst_min_size += tmp;
+ }
+ }
+
+ return worst_min_size;
+}
+
+/*
+ * Add on a 3x multiplier to allow for multiple back-to-back captures occurring
+ * before the i915 can read the data out and process it
+ */
+#define GUC_CAPTURE_OVERBUFFER_MULTIPLIER 3
+
+static void check_guc_capture_size(struct xe_guc *guc)
+{
+ int min_size = guc_capture_output_min_size_est(guc);
+ int spare_size = min_size * GUC_CAPTURE_OVERBUFFER_MULTIPLIER;
+ u32 buffer_size = xe_guc_log_section_size_capture(&guc->log);
+
+ /*
+ * NOTE: min_size is much smaller than the capture region allocation (DG2: <80K vs 1MB)
+ * Additionally, its based on space needed to fit all engines getting reset at once
+ * within the same G2H handler task slot. This is very unlikely. However, if GuC really
+ * does run out of space for whatever reason, we will see an separate warning message
+ * when processing the G2H event capture-notification, search for:
+ * xe_guc_STATE_CAPTURE_EVENT_STATUS_NOSPACE.
+ */
+ if (min_size < 0)
+ xe_gt_warn(guc_to_gt(guc), "Failed to calculate error state capture buffer minimum size: %d!\n",
+ min_size);
+ else if (min_size > buffer_size)
+ xe_gt_warn(guc_to_gt(guc), "Error state capture buffer maybe small: %d < %d\n",
+ buffer_size, min_size);
+ else if (spare_size > buffer_size)
+ xe_gt_dbg(guc_to_gt(guc), "Error state capture buffer lacks spare size: %d < %d (min = %d)\n",
+ buffer_size, spare_size, min_size);
+}
+
int xe_guc_capture_init(struct xe_guc *guc)
{
guc->capture = kzalloc(sizeof(*guc->capture), GFP_KERNEL);
@@ -570,6 +645,7 @@ int xe_guc_capture_init(struct xe_guc *guc)
INIT_LIST_HEAD(&guc->capture->outlist);
INIT_LIST_HEAD(&guc->capture->cachelist);
+ check_guc_capture_size(guc);
return 0;
}
--
2.34.1
