v4.19.13 snapshot.
diff --git a/drivers/scsi/scsi_debugfs.c b/drivers/scsi/scsi_debugfs.c
new file mode 100644
index 0000000..c5a8756
--- /dev/null
+++ b/drivers/scsi/scsi_debugfs.c
@@ -0,0 +1,52 @@
+// SPDX-License-Identifier: GPL-2.0
+#include <linux/seq_file.h>
+#include <scsi/scsi_cmnd.h>
+#include <scsi/scsi_dbg.h>
+#include "scsi_debugfs.h"
+
+#define SCSI_CMD_FLAG_NAME(name)[const_ilog2(SCMD_##name)] = #name
+static const char *const scsi_cmd_flags[] = {
+ SCSI_CMD_FLAG_NAME(TAGGED),
+ SCSI_CMD_FLAG_NAME(UNCHECKED_ISA_DMA),
+ SCSI_CMD_FLAG_NAME(INITIALIZED),
+};
+#undef SCSI_CMD_FLAG_NAME
+
+static int scsi_flags_show(struct seq_file *m, const unsigned long flags,
+ const char *const *flag_name, int flag_name_count)
+{
+ bool sep = false;
+ int i;
+
+ for (i = 0; i < sizeof(flags) * BITS_PER_BYTE; i++) {
+ if (!(flags & BIT(i)))
+ continue;
+ if (sep)
+ seq_puts(m, "|");
+ sep = true;
+ if (i < flag_name_count && flag_name[i])
+ seq_puts(m, flag_name[i]);
+ else
+ seq_printf(m, "%d", i);
+ }
+ return 0;
+}
+
+void scsi_show_rq(struct seq_file *m, struct request *rq)
+{
+ struct scsi_cmnd *cmd = container_of(scsi_req(rq), typeof(*cmd), req);
+ int alloc_ms = jiffies_to_msecs(jiffies - cmd->jiffies_at_alloc);
+ int timeout_ms = jiffies_to_msecs(rq->timeout);
+ const u8 *const cdb = READ_ONCE(cmd->cmnd);
+ char buf[80] = "(?)";
+
+ if (cdb)
+ __scsi_format_command(buf, sizeof(buf), cdb, cmd->cmd_len);
+ seq_printf(m, ", .cmd=%s, .retries=%d, .result = %#x, .flags=", buf,
+ cmd->retries, cmd->result);
+ scsi_flags_show(m, cmd->flags, scsi_cmd_flags,
+ ARRAY_SIZE(scsi_cmd_flags));
+ seq_printf(m, ", .timeout=%d.%03d, allocated %d.%03d s ago",
+ timeout_ms / 1000, timeout_ms % 1000,
+ alloc_ms / 1000, alloc_ms % 1000);
+}