[PATCH v4 12/17] ras: AEST: Allow configuring CE threshold via debugfs

[Ruidong Tian <tianruidong@linux.alibaba.com>]

This commit introduces the ability to configure the Corrected Error (CE)
threshold for AEST records through debugfs. This allows administrators to
dynamically adjust the CE threshold for error reporting.

Signed-off-by: Ruidong Tian <tianruidong@linux.alibaba.com>
---
 Documentation/ABI/testing/debugfs-aest | 16 ++++++++++
 drivers/ras/aest/aest-sysfs.c          | 42 ++++++++++++++++++++++++++
 2 files changed, 58 insertions(+)

diff --git a/Documentation/ABI/testing/debugfs-aest b/Documentation/ABI/testing/debugfs-aest
index a984fcedede2..76ba1b77b274 100644
--- a/Documentation/ABI/testing/debugfs-aest
+++ b/Documentation/ABI/testing/debugfs-aest
@@ -23,6 +23,14 @@ Description:
 		See more at:
 			https://developer.arm.com/documentation/den0085/latest/
 
+What:		/sys/kernel/debug/aest/<name>.<id>/<node_name>/ce_threshold
+Date:		Dec 2025
+KernelVersion	6.19
+Contact:	Ruidong Tian <tianruidong@linux.alibaba.com>
+Description:
+		(WO) Write the ce threshold to all records of this node. Failed
+		if input exceeded the maximum threshold
+
 What:		/sys/kernel/debug/aest/<name>.<id>/<node_name>/err_count
 Date:		Dec 2025
 KernelVersion	6.19
@@ -37,6 +45,14 @@ Contact:	Ruidong Tian <tianruidong@linux.alibaba.com>
 Description:
 		(RO) Read err_* register and return val.
 
+What:		/sys/kernel/debug/aest/<name>.<id>/<node_name>/record<index>/ce_threshold
+Date:		Dec 2025
+KernelVersion	6.19
+Contact:	Ruidong Tian <tianruidong@linux.alibaba.com>
+Description:
+		(RW) Read and write the ce threshold to this record. Failed
+		if input exceeded the maximum threshold
+
 What:		/sys/kernel/debug/aest/<name>.<id>/<node_name>/record<index>/err_count
 Date:		Dec 2025
 KernelVersion	6.19
diff --git a/drivers/ras/aest/aest-sysfs.c b/drivers/ras/aest/aest-sysfs.c
index b54e879506aa..392e7ad8328e 100644
--- a/drivers/ras/aest/aest-sysfs.c
+++ b/drivers/ras/aest/aest-sysfs.c
@@ -7,6 +7,25 @@
 
 #include "aest.h"
 
+static void
+aest_store_threshold(struct aest_record *record, void *data)
+{
+	u64 err_misc0, *threshold = data;
+	struct ce_threshold *ce = &record->ce;
+
+	if (*threshold > ce->info->max_count)
+		return;
+
+	ce->threshold = *threshold;
+	ce->count = ce->info->max_count - ce->threshold + 1;
+
+	err_misc0 = record_read(record, ERXMISC0);
+	ce->reg_val = (err_misc0 & ~ce->info->mask) |
+			(ce->count << ce->info->shift);
+
+	record_write(record, ERXMISC0, ce->reg_val);
+}
+
 static void
 aest_error_count(struct aest_record *record, void *data)
 {
@@ -77,6 +96,27 @@ DEFINE_AEST_DEBUGFS_ATTR(err_misc1, ERXMISC1);
 DEFINE_AEST_DEBUGFS_ATTR(err_misc2, ERXMISC2);
 DEFINE_AEST_DEBUGFS_ATTR(err_misc3, ERXMISC3);
 
+static int record_ce_threshold_get(void *data, u64 *val)
+{
+	struct aest_record *record = data;
+
+	*val = record->ce.threshold;
+	return 0;
+}
+
+static int record_ce_threshold_set(void *data, u64 val)
+{
+	u64 threshold = val;
+	struct aest_record *record = data;
+
+	aest_store_threshold(record, &threshold);
+
+	return 0;
+}
+
+DEFINE_DEBUGFS_ATTRIBUTE(record_ce_threshold_ops, record_ce_threshold_get,
+					record_ce_threshold_set, "%llu\n");
+
 static int aest_record_err_count_show(struct seq_file *m, void *data)
 {
 	struct aest_record *record = m->private;
@@ -116,6 +156,8 @@ static void aest_record_init_debugfs(struct aest_record *record)
 								&err_misc3_ops);
 	debugfs_create_file("err_count", 0400, record->debugfs, record,
 						&aest_record_err_count_fops);
+	debugfs_create_file("ce_threshold", 0600, record->debugfs, record,
+						&record_ce_threshold_ops);
 }
 
 static void
-- 
2.51.2.612.gdc70283dfc