[SCSI] megaraid_sas: cleanup queue command path

This patch (originally submitted by Christoph Hellwig) removes code
duplication in megasas_build_cmd.  It also defines
MEGASAS_IOC_FIRMWARE32 to allow 64 bit compiled applications to work.
Signed-off-by: Sumant Patro <Sumant.Patro@lsil.com>

Rejections fixed and
Signed-off-by: James Bottomley <James.Bottomley@SteelEye.com>

Documentation/scsi/ChangeLog.megaraid_sas

+1 Release Date    : Mon Dec 19 14:36:26 PST 2005 - Sumant Patro <Sumant.Patro@lsil.com>
+2 Current Version : 00.00.02.00-rc4 
+3 Older Version   : 00.00.02.01 
+
+i.	Code reorganized to remove code duplication in megasas_build_cmd. 
+
+	"There's a lot of duplicate code megasas_build_cmd.  Move that out of the different codepathes and merge the reminder of megasas_build_cmd into megasas_queue_command"
+
+		- Christoph Hellwig <hch@lst.de>
+
+ii.	Defined MEGASAS_IOC_FIRMWARE32 for code paths that handles 32 bit applications in 64 bit systems.
+
+	"MEGASAS_IOC_FIRMWARE can't be redefined if CONFIG_COMPAT is set, we need to define a MEGASAS_IOC_FIRMWARE32 define so native binaries continue to work"
+
+		- Christoph Hellwig <hch@lst.de>

drivers/scsi/megaraid/megaraid_sas.c

@@ -10,7 +10,7 @@
  *	   2 of the License, or (at your option) any later version.
  *
  * FILE		: megaraid_sas.c
- * Version	: v00.00.02.00-rc4
+ * Version	: v00.00.02.01
  *
  * Authors:
  * 	Sreenivas Bagalkote	<Sreenivas.Bagalkote@lsil.com>
@@ -558,36 +558,17 @@ megasas_build_ldio(struct megasas_instance *instance, struct scsi_cmnd *scp,
 }
 
 /**
- * megasas_build_cmd -	Prepares a command packet
- * @instance:		Adapter soft state
- * @scp:		SCSI command
- * @frame_count:	[OUT] Number of frames used to prepare this command
+ * megasas_is_ldio -		Checks if the cmd is for logical drive
+ * @scmd:			SCSI command
+ *	
+ * Called by megasas_queue_command to find out if the command to be queued
+ * is a logical drive command	
  */
-static struct megasas_cmd *megasas_build_cmd(struct megasas_instance
-						    *instance,
-						    struct scsi_cmnd *scp,
-						    int *frame_count)
+static inline int megasas_is_ldio(struct scsi_cmnd *cmd)
 {
-	u32 logical_cmd;
-	struct megasas_cmd *cmd;
-
-	/*
-	 * Find out if this is logical or physical drive command.
-	 */
-	logical_cmd = MEGASAS_IS_LOGICAL(scp);
-
-	/*
-	 * Logical drive command
-	 */
-	if (logical_cmd) {
-
-		if (scp->device->id >= MEGASAS_MAX_LD) {
-			scp->result = DID_BAD_TARGET << 16;
-			return NULL;
-		}
-
-		switch (scp->cmnd[0]) {
-
+	if (!MEGASAS_IS_LOGICAL(cmd))
+		return 0;
+	switch (cmd->cmnd[0]) {
 	case READ_10:
 	case WRITE_10:
 	case READ_12:
@@ -596,74 +577,10 @@ static struct megasas_cmd *megasas_build_cmd(struct megasas_instance
 	case WRITE_6:
 	case READ_16:
 	case WRITE_16:
-			/*
-			 * Fail for LUN > 0
-			 */
-			if (scp->device->lun) {
-				scp->result = DID_BAD_TARGET << 16;
-				return NULL;
-			}
-
-			cmd = megasas_get_cmd(instance);
-
-			if (!cmd) {
-				scp->result = DID_IMM_RETRY << 16;
-				return NULL;
-			}
-
-			*frame_count = megasas_build_ldio(instance, scp, cmd);
-
-			if (!(*frame_count)) {
-				megasas_return_cmd(instance, cmd);
-				return NULL;
-			}
-
-			return cmd;
-
+		return 1;
 	default:
-			/*
-			 * Fail for LUN > 0
-			 */
-			if (scp->device->lun) {
-				scp->result = DID_BAD_TARGET << 16;
-				return NULL;
-			}
-
-			cmd = megasas_get_cmd(instance);
-
-			if (!cmd) {
-				scp->result = DID_IMM_RETRY << 16;
-				return NULL;
-			}
-
-			*frame_count = megasas_build_dcdb(instance, scp, cmd);
-
-			if (!(*frame_count)) {
-				megasas_return_cmd(instance, cmd);
-				return NULL;
-			}
-
-			return cmd;
-		}
-	} else {
-		cmd = megasas_get_cmd(instance);
-
-		if (!cmd) {
-			scp->result = DID_IMM_RETRY << 16;
-			return NULL;
-		}
-
-		*frame_count = megasas_build_dcdb(instance, scp, cmd);
-
-		if (!(*frame_count)) {
-			megasas_return_cmd(instance, cmd);
-			return NULL;
-		}
-
-		return cmd;
+		return 0;
 	}
-
-	return NULL;
 }
 
 /**
@@ -684,13 +601,27 @@ megasas_queue_command(struct scsi_cmnd *scmd, void (*done) (struct scsi_cmnd *))
 	scmd->scsi_done = done;
 	scmd->result = 0;
 
-	cmd = megasas_build_cmd(instance, scmd, &frame_count);
-
-	if (!cmd) {
-		done(scmd);
-		return 0;
+	if (MEGASAS_IS_LOGICAL(scmd) &&
+	    (scmd->device->id >= MEGASAS_MAX_LD || scmd->device->lun)) {
+		scmd->result = DID_BAD_TARGET << 16;
+		goto out_done;
 	}
 
+	cmd = megasas_get_cmd(instance);
+	if (!cmd)
+		return SCSI_MLQUEUE_HOST_BUSY;
+
+	/*
+	 * Logical drive command
+	 */
+	if (megasas_is_ldio(scmd))
+		frame_count = megasas_build_ldio(instance, scmd, cmd);
+	else
+		frame_count = megasas_build_dcdb(instance, scmd, cmd);
+
+	if (!frame_count)
+		goto out_return_cmd;
+
 	cmd->scmd = scmd;
 	scmd->SCp.ptr = (char *)cmd;
 	scmd->SCp.sent_command = jiffies;
@@ -706,6 +637,12 @@ megasas_queue_command(struct scsi_cmnd *scmd, void (*done) (struct scsi_cmnd *))
 	       &instance->reg_set->inbound_queue_port);
 
 	return 0;
+
+ out_return_cmd:
+	megasas_return_cmd(instance, cmd);
+ out_done:
+	done(scmd);
+	return 0;
 }
 
 /**
@@ -2681,9 +2618,8 @@ megasas_mgmt_compat_ioctl(struct file *file, unsigned int cmd,
 			  unsigned long arg)
 {
 	switch (cmd) {
-	case MEGASAS_IOC_FIRMWARE:{
+	case MEGASAS_IOC_FIRMWARE32:
 		return megasas_mgmt_compat_ioctl_fw(file, arg);
-		}
 	case MEGASAS_IOC_GET_AEN:
 		return megasas_mgmt_ioctl_aen(file, arg);
 	}

drivers/scsi/megaraid/megaraid_sas.h

@@ -18,10 +18,9 @@
 /**
  * MegaRAID SAS Driver meta data
  */
-#define MEGASAS_VERSION				"00.00.02.00-rc4"
-#define MEGASAS_RELDATE				"Sep 16, 2005"
-#define MEGASAS_EXT_VERSION			"Fri Sep 16 12:37:08 EDT 2005"
-
+#define MEGASAS_VERSION				"00.00.02.01"
+#define MEGASAS_RELDATE				"Dec 19, 2005"
+#define MEGASAS_EXT_VERSION			"Mon Dec 19 14:36:26 PST 2005"
 /*
  * =====================================
  * MegaRAID SAS MFI firmware definitions
@@ -1125,11 +1124,10 @@ struct compat_megasas_iocpacket {
 	struct compat_iovec sgl[MAX_IOCTL_SGE];
 } __attribute__ ((packed));
 
-#define MEGASAS_IOC_FIRMWARE	_IOWR('M', 1, struct compat_megasas_iocpacket)
-#else
-#define MEGASAS_IOC_FIRMWARE	_IOWR('M', 1, struct megasas_iocpacket)
 #endif
 
+#define MEGASAS_IOC_FIRMWARE	_IOWR('M', 1, struct megasas_iocpacket)
+#define MEGASAS_IOC_FIRMWARE32	_IOWR('M', 1, struct compat_megasas_iocpacket)
 #define MEGASAS_IOC_GET_AEN	_IOW('M', 3, struct megasas_aen)
 
 struct megasas_mgmt_info {