[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>

3 files changed, 68 insertions, 119 deletions

diff --git a/Documentation/scsi/ChangeLog.megaraid_sas b/Documentation/scsi/ChangeLog.megaraid_sas
new file mode 100644
index 000000000000..e2319aeffbcc
--- /dev/null
+++ b/Documentation/scsi/ChangeLog.megaraid_sas
@@ -0,0 +1,15 @@
+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>
diff --git a/drivers/scsi/megaraid/megaraid_sas.c b/drivers/scsi/megaraid/megaraid_sas.c
index 511ed52a5807..2fb53af8de2a 100644
--- a/drivers/scsi/megaraid/megaraid_sas.c
+++ b/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>
@@ -558,112 +558,29 @@ 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]) {
-
-                case READ_10:
-                case WRITE_10:
-                case READ_12:
-                case WRITE_12:
-                case READ_6:
-                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;
-
-                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;
+        if (!MEGASAS_IS_LOGICAL(cmd))
+                return 0;
+        switch (cmd->cmnd[0]) {
+        case READ_10:
+        case WRITE_10:
+        case READ_12:
+        case WRITE_12:
+        case READ_6:
+        case WRITE_6:
+        case READ_16:
+        case WRITE_16:
+                return 1;
+        default:
+                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:{
-                        return megasas_mgmt_compat_ioctl_fw(file, arg);
-                }
+        case MEGASAS_IOC_FIRMWARE32:
+                return megasas_mgmt_compat_ioctl_fw(file, arg);
         case MEGASAS_IOC_GET_AEN:
                 return megasas_mgmt_ioctl_aen(file, arg);
         }
diff --git a/drivers/scsi/megaraid/megaraid_sas.h b/drivers/scsi/megaraid/megaraid_sas.h
index eaec9d531424..67e07d30258f 100644
--- a/drivers/scsi/megaraid/megaraid_sas.h
+++ b/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 {