v4.19.13 snapshot.
diff --git a/drivers/scsi/scsi_logging.h b/drivers/scsi/scsi_logging.h
new file mode 100644
index 0000000..836185d
--- /dev/null
+++ b/drivers/scsi/scsi_logging.h
@@ -0,0 +1,85 @@
+/* SPDX-License-Identifier: GPL-2.0 */
+#ifndef _SCSI_LOGGING_H
+#define _SCSI_LOGGING_H
+
+
+/*
+ * This defines the scsi logging feature. It is a means by which the user can
+ * select how much information they get about various goings on, and it can be
+ * really useful for fault tracing. The logging word is divided into 10 3-bit
+ * bitfields, each of which describes a loglevel. The division of things is
+ * somewhat arbitrary, and the division of the word could be changed if it
+ * were really needed for any reason. The numbers below are the only place
+ * where these are specified. For a first go-around, 3 bits is more than
+ * enough, since this gives 8 levels of logging (really 7, since 0 is always
+ * off). Cutting to 2 bits might be wise at some point.
+ */
+
+#define SCSI_LOG_ERROR_SHIFT 0
+#define SCSI_LOG_TIMEOUT_SHIFT 3
+#define SCSI_LOG_SCAN_SHIFT 6
+#define SCSI_LOG_MLQUEUE_SHIFT 9
+#define SCSI_LOG_MLCOMPLETE_SHIFT 12
+#define SCSI_LOG_LLQUEUE_SHIFT 15
+#define SCSI_LOG_LLCOMPLETE_SHIFT 18
+#define SCSI_LOG_HLQUEUE_SHIFT 21
+#define SCSI_LOG_HLCOMPLETE_SHIFT 24
+#define SCSI_LOG_IOCTL_SHIFT 27
+
+#define SCSI_LOG_ERROR_BITS 3
+#define SCSI_LOG_TIMEOUT_BITS 3
+#define SCSI_LOG_SCAN_BITS 3
+#define SCSI_LOG_MLQUEUE_BITS 3
+#define SCSI_LOG_MLCOMPLETE_BITS 3
+#define SCSI_LOG_LLQUEUE_BITS 3
+#define SCSI_LOG_LLCOMPLETE_BITS 3
+#define SCSI_LOG_HLQUEUE_BITS 3
+#define SCSI_LOG_HLCOMPLETE_BITS 3
+#define SCSI_LOG_IOCTL_BITS 3
+
+extern unsigned int scsi_logging_level;
+
+#ifdef CONFIG_SCSI_LOGGING
+
+#define SCSI_LOG_LEVEL(SHIFT, BITS) \
+ ((scsi_logging_level >> (SHIFT)) & ((1 << (BITS)) - 1))
+
+#define SCSI_CHECK_LOGGING(SHIFT, BITS, LEVEL, CMD) \
+do { \
+ if (unlikely((SCSI_LOG_LEVEL(SHIFT, BITS)) > (LEVEL))) \
+ do { \
+ CMD; \
+ } while (0); \
+} while (0)
+#else
+#define SCSI_LOG_LEVEL(SHIFT, BITS) 0
+#define SCSI_CHECK_LOGGING(SHIFT, BITS, LEVEL, CMD)
+#endif /* CONFIG_SCSI_LOGGING */
+
+/*
+ * These are the macros that are actually used throughout the code to
+ * log events. If logging isn't enabled, they are no-ops and will be
+ * completely absent from the user's code.
+ */
+#define SCSI_LOG_ERROR_RECOVERY(LEVEL,CMD) \
+ SCSI_CHECK_LOGGING(SCSI_LOG_ERROR_SHIFT, SCSI_LOG_ERROR_BITS, LEVEL,CMD);
+#define SCSI_LOG_TIMEOUT(LEVEL,CMD) \
+ SCSI_CHECK_LOGGING(SCSI_LOG_TIMEOUT_SHIFT, SCSI_LOG_TIMEOUT_BITS, LEVEL,CMD);
+#define SCSI_LOG_SCAN_BUS(LEVEL,CMD) \
+ SCSI_CHECK_LOGGING(SCSI_LOG_SCAN_SHIFT, SCSI_LOG_SCAN_BITS, LEVEL,CMD);
+#define SCSI_LOG_MLQUEUE(LEVEL,CMD) \
+ SCSI_CHECK_LOGGING(SCSI_LOG_MLQUEUE_SHIFT, SCSI_LOG_MLQUEUE_BITS, LEVEL,CMD);
+#define SCSI_LOG_MLCOMPLETE(LEVEL,CMD) \
+ SCSI_CHECK_LOGGING(SCSI_LOG_MLCOMPLETE_SHIFT, SCSI_LOG_MLCOMPLETE_BITS, LEVEL,CMD);
+#define SCSI_LOG_LLQUEUE(LEVEL,CMD) \
+ SCSI_CHECK_LOGGING(SCSI_LOG_LLQUEUE_SHIFT, SCSI_LOG_LLQUEUE_BITS, LEVEL,CMD);
+#define SCSI_LOG_LLCOMPLETE(LEVEL,CMD) \
+ SCSI_CHECK_LOGGING(SCSI_LOG_LLCOMPLETE_SHIFT, SCSI_LOG_LLCOMPLETE_BITS, LEVEL,CMD);
+#define SCSI_LOG_HLQUEUE(LEVEL,CMD) \
+ SCSI_CHECK_LOGGING(SCSI_LOG_HLQUEUE_SHIFT, SCSI_LOG_HLQUEUE_BITS, LEVEL,CMD);
+#define SCSI_LOG_HLCOMPLETE(LEVEL,CMD) \
+ SCSI_CHECK_LOGGING(SCSI_LOG_HLCOMPLETE_SHIFT, SCSI_LOG_HLCOMPLETE_BITS, LEVEL,CMD);
+#define SCSI_LOG_IOCTL(LEVEL,CMD) \
+ SCSI_CHECK_LOGGING(SCSI_LOG_IOCTL_SHIFT, SCSI_LOG_IOCTL_BITS, LEVEL,CMD);
+
+#endif /* _SCSI_LOGGING_H */