[PATCH 1/3] drm/amdgpu: Warn when bad pages approaches 90% threshold

[Kent Russell]

Currently dmesg doesn't warn when the number of bad pages approaches the
threshold for page retirement. WARN when the number of bad pages
is at 90% or greater for easier checks and planning, instead of waiting
until the GPU is full of bad pages

Cc: Luben Tuikov <luben.tuikov at amd.com>
Cc: Mukul Joshi <Mukul.Joshi at amd.com>
Signed-off-by: Kent Russell <kent.russell at amd.com>
---
 drivers/gpu/drm/amd/amdgpu/amdgpu_ras_eeprom.c | 17 +++++++++++++++++
 1 file changed, 17 insertions(+)

diff --git a/drivers/gpu/drm/amd/amdgpu/amdgpu_ras_eeprom.c b/drivers/gpu/drm/amd/amdgpu/amdgpu_ras_eeprom.c
index f4c05ff4b26c..1ede0f0d6f55 100644
--- a/drivers/gpu/drm/amd/amdgpu/amdgpu_ras_eeprom.c
+++ b/drivers/gpu/drm/amd/amdgpu/amdgpu_ras_eeprom.c
@@ -1071,12 +1071,29 @@ int amdgpu_ras_eeprom_init(struct amdgpu_ras_eeprom_control *control,
 	control->ras_fri = RAS_OFFSET_TO_INDEX(control, hdr->first_rec_offset);
 
 	if (hdr->header == RAS_TABLE_HDR_VAL) {
+		int threshold = 0;
 		DRM_DEBUG_DRIVER("Found existing EEPROM table with %d records",
 				 control->ras_num_recs);
 		res = __verify_ras_table_checksum(control);
 		if (res)
 			DRM_ERROR("RAS table incorrect checksum or error:%d\n",
 				  res);
+
+		/* threshold = 0 means that page retirement is disabled, while
+		 * threshold = -1 means default behaviour
+		 */
+		if (amdgpu_bad_page_threshold == -1)
+			threshold = ras->bad_page_cnt_threshold;
+		else if (amdgpu_bad_page_threshold > 0)
+			threshold = amdgpu_bad_page_threshold;
+
+		/* Since multiplcation is transitive, a = 9b/10 is the same
+		 * as 10a = 9b. Use this for our 90% limit to avoid rounding
+		 */
+		if (threshold > 0 && ((control->ras_num_recs * 10) >= (threshold * 9)))
+			DRM_WARN("RAS records:%u exceeds 90%% of threshold:%d",
+					control->ras_num_recs,
+					threshold);
 	} else if (hdr->header == RAS_TABLE_HDR_BAD &&
 		   amdgpu_bad_page_threshold != 0) {
 		res = __verify_ras_table_checksum(control);
-- 
2.25.1