Support for providing sense data for REQUEST SENSE (#120)

* Error() supports passing Sense Key and ASC, REQUEST SENSE returns these data

* Synchronized error handlign with sasidev_ctrl

* Added warning for missing sense key

* Logging and comment update

* Updated invalid LUN handling

* Updated REQUEST SENSE

* Revert "Updated REQUEST SENSE"

This reverts commit 61a1ecbca7.

* Report MEDIUM NOT PRESENT if capacity cannot be determined

* Updated handling of non-existing LUNs. This change results issue #124.

* Log a warning if drive capacity cannot be determined

* Added enums for sense keys and ASCs

* Updated Error() signature to use enums

* Fixed compiler warnings

* Merge with develop branch

src/raspberrypi/controllers/sasidev_ctrl.cpp

@@ -466,11 +466,12 @@ void FASTCALL SASIDEV::Command()
 
 		// Execution Phase
                 try {
-                        Execute();
+                    Execute();
                 }
                 catch (lunexception& e) {
-                        LOGINFO("%s unsupported LUN %d", __PRETTY_FUNCTION__, (int)e.getlun());
+                	LOGINFO("%s Invalid LUN %d", __PRETTY_FUNCTION__, (int)e.getlun());
-                        Error();
+
+                	Error(ERROR_CODES::sense_key::ILLEGAL_REQUEST, ERROR_CODES::asc::INVALID_LUN);
                 }
 		#else
 		// Request the command
@@ -513,6 +514,12 @@ void FASTCALL SASIDEV::Execute()
 	ctrl.execstart = SysTimer::GetTimerLow();
 	#endif	// RASCSI
 
+	// Discard pending sense data from the previous command if the current command is not REQUEST SENSE
+	if ((SASIDEV::scsi_command)ctrl.cmd[0] != eCmdRequestSense) {
+		ctrl.sense_key = 0;
+		ctrl.asc = 0;
+	}
+
 	// Process by command
 	switch ((SASIDEV::scsi_command)ctrl.cmd[0]) {
 		// TEST UNIT READY
@@ -830,7 +837,7 @@ void FASTCALL SASIDEV::DataOut()
 //	Error
 //
 //---------------------------------------------------------------------------
-void FASTCALL SASIDEV::Error()
+void FASTCALL SASIDEV::Error(ERROR_CODES::sense_key sense_key, ERROR_CODES::asc asc)
 {
 	// Get bus information
 	((GPIOBUS*)ctrl.bus)->Aquire();
@@ -851,9 +858,11 @@ void FASTCALL SASIDEV::Error()
 		return;
 	}
 
-#if defined(DISK_LOG)
+	LOGTRACE("%s Sense Key and ASC for subsequent REQUEST SENSE: $%02X, $%02X", __PRETTY_FUNCTION__, sense_key, asc);
-	LOGWARN("Error occured (going to status phase)");
+
-#endif	// DISK_LOG
+	// Set Sense Key and ASC for a subsequent REQUEST SENSE
+	ctrl.sense_key = sense_key;
+	ctrl.asc = asc;
 
 	// Logical Unit
 	DWORD lun = (ctrl.cmd[1] >> 5) & 0x07;
@@ -861,6 +870,10 @@ void FASTCALL SASIDEV::Error()
 	// Set status and message(CHECK CONDITION)
 	ctrl.status = (lun << 5) | 0x02;
 
+#if defined(DISK_LOG)
+	LOGWARN("Error occured (going to status phase)");
+#endif	// DISK_LOG
+
 	// status phase
 	Status();
 }
@@ -920,13 +933,36 @@ void FASTCALL SASIDEV::CmdRequestSense()
 {
 	LOGTRACE( "%s REQUEST SENSE Command ", __PRETTY_FUNCTION__);
 
-        DWORD lun = GetLun();
+    DWORD lun;
+    try {
+     	lun = GetLun();
+    }
+    catch(const lunexception& e) {
+        LOGINFO("%s Non-existing LUN %d", __PRETTY_FUNCTION__, (int)e.getlun());
+
+        // Note: According to the SCSI specs the LUN handling for REQUEST SENSE is special.
+        // Non-existing LUNs do *not* result in CHECK CONDITION.
+        // Only the Sense Key and ASC are set in order to signal the non-existing LUN.
+
+        // LUN 0 can be assumed to be present (required to call RequestSense() below)
+        lun = 0;
+
+    	ctrl.sense_key = ERROR_CODES::sense_key::ILLEGAL_REQUEST;
+    	ctrl.asc = ERROR_CODES::asc::INVALID_LUN;
+    }
 
 	ctrl.length = ctrl.unit[lun]->RequestSense(ctrl.cmd, ctrl.buffer);
 	ASSERT(ctrl.length > 0);
 
+    LOGTRACE("%s Sense Key $%02X, ASC $%02X",__PRETTY_FUNCTION__, ctrl.sense_key, ctrl.asc);
 
-	LOGTRACE("%s Sense key $%02X, ASC $%02X",__PRETTY_FUNCTION__, (WORD)ctrl.buffer[2], (WORD)ctrl.buffer[12]);
+    // REQUEST SENSE returns the sense data set by the previous (failed) command
+    ctrl.buffer[2] = ctrl.sense_key;
+    ctrl.buffer[12] = ctrl.asc;
+
+    // The sense data are only valid once
+    ctrl.sense_key = 0;
+    ctrl.asc = 0;
 
 	// Read phase
 	DataIn();
@@ -1240,8 +1276,7 @@ void FASTCALL SASIDEV::CmdInvalid()
 {
 	LOGWARN("%s Command not supported", __PRETTY_FUNCTION__);
 
-	// Failure (Error)
+	Error(ERROR_CODES::sense_key::ILLEGAL_REQUEST, ERROR_CODES::asc::INVALID_COMMAND_OPERATION_CODE);
-	Error();
 }
 
 //===========================================================================
@@ -1519,7 +1554,14 @@ void FASTCALL SASIDEV::ReceiveNext()
 		// Command phase
 		case BUS::command:
 			// Execution Phase
-			Execute();
+            try {
+                Execute();
+            }
+            catch (const lunexception& e) {
+                LOGINFO("%s unsupported LUN %d", __PRETTY_FUNCTION__, (int)e.getlun());
+                // LOGICAL UNIT NOT SUPPORTED
+                Error(SENSE_KEY_ILLEGAL_REQUEST, ASC_INVALID_LUN);
+            }
 			break;
 			#endif	// RASCSI
 

src/raspberrypi/controllers/sasidev_ctrl.h

@@ -135,12 +135,16 @@ public:
 		BYTE *buffer;					// Transfer data buffer
 		int bufsize;					// Transfer data buffer size
 		DWORD blocks;					// Number of transfer block
-		DWORD next;					// Next record
+		DWORD next;						// Next record
 		DWORD offset;					// Transfer offset
 		DWORD length;					// Transfer remaining length
 
 		// Logical unit
-		Disk *unit[UnitMax];				// Logical Unit
+		Disk *unit[UnitMax];
+
+		// Sense Key and Additional Sense Code (ASC) of the previous command
+		int sense_key;
+		int asc;
 	} ctrl_t;
 
 public:
@@ -194,7 +198,8 @@ protected:
 	void FASTCALL MsgIn();							// Message in phase
 	void FASTCALL DataIn();							// Data in phase
 	void FASTCALL DataOut();						// Data out phase
-	virtual void FASTCALL Error();						// Common error handling
+	virtual void FASTCALL Error(ERROR_CODES::sense_key sense_key = ERROR_CODES::sense_key::NO_SENSE,
+			ERROR_CODES::asc = ERROR_CODES::asc::NO_ADDITIONAL_SENSE_INFORMATION);	// Common error handling
 
 	// commands
 	void FASTCALL CmdTestUnitReady();					// TEST UNIT READY command

src/raspberrypi/controllers/scsidev_ctrl.cpp

@@ -307,6 +307,12 @@ void FASTCALL SCSIDEV::Execute()
 
 	LOGDEBUG("++++ CMD ++++ %s Received %s ($%02X)", __PRETTY_FUNCTION__, command->name, (unsigned int)ctrl.cmd[0]);
 
+	// Discard pending sense data from the previous command if the current command is not REQUEST SENSE
+	if ((unsigned int)ctrl.cmd[0] != 0x03) {
+		ctrl.sense_key = 0;
+		ctrl.asc = 0;
+	}
+
 	// Process by command
 	(this->*command->execute)();
 }
@@ -361,7 +367,7 @@ void FASTCALL SCSIDEV::MsgOut()
 //	Common Error Handling
 //
 //---------------------------------------------------------------------------
-void FASTCALL SCSIDEV::Error()
+void FASTCALL SCSIDEV::Error(ERROR_CODES::sense_key sense_key, ERROR_CODES::asc asc)
 {
 	// Get bus information
 	((GPIOBUS*)ctrl.bus)->Aquire();
@@ -382,12 +388,18 @@ void FASTCALL SCSIDEV::Error()
 		return;
 	}
 
-	LOGTRACE( "%s Error (to status phase)", __PRETTY_FUNCTION__);
+	LOGTRACE("%s Sense Key and ASC for subsequent REQUEST SENSE: $%02X, $%02X", __PRETTY_FUNCTION__, sense_key, asc);
+
+	// Set Sense Key and ASC for a subsequent REQUEST SENSE
+	ctrl.sense_key = sense_key;
+	ctrl.asc = asc;
 
 	// Set status and message(CHECK CONDITION)
 	ctrl.status = 0x02;
 	ctrl.message = 0x00;
 
+	LOGTRACE("%s Error (to status phase)", __PRETTY_FUNCTION__);
+
 	// status phase
 	Status();
 }
@@ -411,10 +423,10 @@ void FASTCALL SCSIDEV::CmdInquiry()
 	// TODO The code below is most likely wrong. It results in the same INQUIRY data being
 	// used for all LUNs, even though each LUN has its individual set of INQUIRY data.
 	Disk *disk = NULL;
-	int lun;
+	int valid_lun;
-	for (lun = 0; lun < UnitMax; lun++) {
+	for (valid_lun = 0; valid_lun < UnitMax; valid_lun++) {
-		if (ctrl.unit[lun]) {
+		if (ctrl.unit[valid_lun]) {
-			disk = ctrl.unit[lun];
+			disk = ctrl.unit[valid_lun];
 			break;
 		}
 	}
@@ -425,7 +437,7 @@ void FASTCALL SCSIDEV::CmdInquiry()
 		DWORD minor = (DWORD)(RASCSI & 0xff);
 		LOGTRACE("%s Buffer size is %d",__PRETTY_FUNCTION__, ctrl.bufsize);
 		ctrl.length =
-			ctrl.unit[lun]->Inquiry(ctrl.cmd, ctrl.buffer, major, minor);
+			ctrl.unit[valid_lun]->Inquiry(ctrl.cmd, ctrl.buffer, major, minor);
 	} else {
 		ctrl.length = 0;
 	}
@@ -441,6 +453,12 @@ void FASTCALL SCSIDEV::CmdInquiry()
 		ctrl.buffer[7] |= (1 << 4);
 	}
 
+	// Report if the device does not support the requested LUN
+	DWORD lun = (ctrl.cmd[1] >> 5) & 0x07;
+	if (!ctrl.unit[lun]) {
+		ctrl.buffer[0] |= 0x7f;
+	}
+
 	// Data-in Phase
 	DataIn();
 }
@@ -650,7 +668,7 @@ void FASTCALL SCSIDEV::CmdReadCapacity()
 	int length = ctrl.unit[lun]->ReadCapacity(ctrl.cmd, ctrl.buffer);
 	ASSERT(length >= 0);
 	if (length <= 0) {
-		Error();
+		Error(ERROR_CODES::sense_key::ILLEGAL_REQUEST, ERROR_CODES::asc::MEDIUM_NOT_PRESENT);
 		return;
 	}
 
@@ -1510,11 +1528,12 @@ void FASTCALL SCSIDEV::Receive()
 
 			// Execution Phase
                         try {
-                                Execute();
+                        	Execute();
                         }
-                        catch (lunexception& e) {
+                        catch (const lunexception& e) {
-                                LOGINFO("%s unsupported LUN %d", __PRETTY_FUNCTION__, (int)e.getlun());
+                            LOGINFO("%s Invalid LUN %d", __PRETTY_FUNCTION__, (int)e.getlun());
-                                Error();
+
+                            Error(ERROR_CODES::sense_key::ILLEGAL_REQUEST, ERROR_CODES::asc::INVALID_LUN);
                         }
 			break;
 

src/raspberrypi/controllers/scsidev_ctrl.h

@@ -74,7 +74,8 @@ private:
 	void FASTCALL Selection();						// Selection phase
 	void FASTCALL Execute();						// Execution phase
 	void FASTCALL MsgOut();							// Message out phase
-	void FASTCALL Error();							// Common erorr handling
+	void FASTCALL Error(ERROR_CODES::sense_key sense_key = ERROR_CODES::sense_key::NO_SENSE,
+			ERROR_CODES::asc asc = ERROR_CODES::asc::NO_ADDITIONAL_SENSE_INFORMATION);	// Common erorr handling
 
 	// commands
 	void FASTCALL CmdInquiry();						// INQUIRY command

src/raspberrypi/devices/disk.cpp

@@ -1216,7 +1216,10 @@ int FASTCALL Disk::RequestSense(const DWORD *cdb, BYTE *buf)
 	memset(buf, 0, size);
 
 	// Set 18 bytes including extended sense data
+
+	// Current error
 	buf[0] = 0x70;
+
 	buf[2] = (BYTE)(disk.code >> 16);
 	buf[7] = 10;
 	buf[12] = (BYTE)(disk.code >> 8);
@@ -2152,8 +2155,13 @@ int FASTCALL Disk::ReadCapacity(const DWORD* /*cdb*/, BYTE *buf)
 		return 0;
 	}
 
+	if (disk.blocks <= 0) {
+		LOGWARN("%s Capacity not available, medium may not be present", __PRETTY_FUNCTION__);
+
+		return -1;
+	}
+
 	// Create end of logical block address (disk.blocks-1)
-	ASSERT(disk.blocks > 0);
 	blocks = disk.blocks - 1;
 	buf[0] = (BYTE)(blocks >> 24);
 	buf[1] = (BYTE)(blocks >> 16);

src/raspberrypi/exceptions.h

@@ -23,7 +23,7 @@ public:
 
         ~lunexception() { }
 
-        DWORD getlun() {
+        DWORD getlun() const {
             return lun;
         }
 };

src/raspberrypi/scsi.h

@@ -12,6 +12,28 @@
 #if !defined(scsi_h)
 #define scsi_h
 
+//===========================================================================
+//
+//	Sense Keys and Additional Sense Codes
+//  (See https://www.t10.org/lists/1spc-lst.htm)
+//
+//===========================================================================
+class ERROR_CODES
+{
+public:
+	enum sense_key : int {
+		NO_SENSE = 0x00,
+		ILLEGAL_REQUEST = 0x05
+	};
+
+	enum asc : int {
+		NO_ADDITIONAL_SENSE_INFORMATION = 0x00,
+		INVALID_COMMAND_OPERATION_CODE = 0x20,
+		INVALID_LUN = 0x25,
+		MEDIUM_NOT_PRESENT = 0x3a
+	};
+};
+
 //===========================================================================
 //
 //	SASI/SCSI Bus