scsi: hisi_sas: Snapshot HW cache of IOST and ITCT at debugfs

The value of IOST/ITCT is updated to cache first, and then synchronize to
DDR periodically. So the value in IOST/ITCT cache is the latest data and
it's important for debugging.

So, the HW cache of IOST and ITCT should be snapshot at debugfs.

Signed-off-by: Luo Jiaxing <luojiaxing@huawei.com>
Signed-off-by: John Garry <john.garry@huawei.com>
Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com>

1 files changed, 17 insertions, 0 deletions

diff --git a/drivers/scsi/hisi_sas/hisi_sas.h b/drivers/scsi/hisi_sas/hisi_sas.h
index c1b56b482a23..5a2fbbbed53e 100644
--- a/drivers/scsi/hisi_sas/hisi_sas.h
+++ b/drivers/scsi/hisi_sas/hisi_sas.h
@@ -36,6 +36,9 @@
 #define HISI_SAS_UNRESERVED_IPTT \
 	(HISI_SAS_MAX_COMMANDS - HISI_SAS_RESERVED_IPTT)
 
+#define HISI_SAS_IOST_ITCT_CACHE_NUM 64
+#define HISI_SAS_IOST_ITCT_CACHE_DW_SZ 10
+
 #define HISI_SAS_STATUS_BUF_SZ (sizeof(struct hisi_sas_status_buffer))
 #define HISI_SAS_COMMAND_TABLE_SZ (sizeof(union hisi_sas_command_table))
 
@@ -252,6 +255,15 @@ struct hisi_sas_debugfs_reg {
 	};
 };
 
+struct hisi_sas_iost_itct_cache {
+	u32 data[HISI_SAS_IOST_ITCT_CACHE_DW_SZ];
+};
+
+enum hisi_sas_debugfs_cache_type {
+	HISI_SAS_ITCT_CACHE,
+	HISI_SAS_IOST_CACHE,
+};
+
 struct hisi_sas_hw {
 	int (*hw_init)(struct hisi_hba *hisi_hba);
 	void (*setup_itct)(struct hisi_hba *hisi_hba,
@@ -294,6 +306,9 @@ struct hisi_sas_hw {
 					  int delay_ms, int timeout_ms);
 	void (*snapshot_prepare)(struct hisi_hba *hisi_hba);
 	void (*snapshot_restore)(struct hisi_hba *hisi_hba);
+	void (*read_iost_itct_cache)(struct hisi_hba *hisi_hba,
+				     enum hisi_sas_debugfs_cache_type type,
+				     u32 *cache);
 	int complete_hdr_size;
 	struct scsi_host_template *sht;
 
@@ -379,6 +394,8 @@ struct hisi_hba {
 	struct hisi_sas_cmd_hdr	*debugfs_cmd_hdr[HISI_SAS_MAX_QUEUES];
 	struct hisi_sas_iost *debugfs_iost;
 	struct hisi_sas_itct *debugfs_itct;
+	u64 *debugfs_iost_cache;
+	u64 *debugfs_itct_cache;
 
 	struct dentry *debugfs_dir;
 	struct dentry *debugfs_dump_dentry;