Add SG_IO ioctl to cciss

The cciss driver is actually capable of sending SCSI CDB to the
controller. So it would only be logical to have it accepting 
SG_IO ioctl, too.
Now we can use all the nice sg_utils and get a persistent device name
for free, too.

Signed-off-by: Hannes Reinecke <hare@suse.de>

diff --git a/drivers/block/cciss.c b/drivers/block/cciss.c
index 0c716ee..33e7b83 100644
--- a/drivers/block/cciss.c
+++ b/drivers/block/cciss.c
@@ -45,6 +45,9 @@ #include <linux/dma-mapping.h>
 #include <linux/blkdev.h>
 #include <linux/genhd.h>
 #include <linux/completion.h>
+#include <scsi/scsi.h>
+#include <scsi/scsi_ioctl.h>
+#include <scsi/sg.h>
 
 #define CCISS_DRIVER_VERSION(maj,min,submin) ((maj<<16)|(min<<8)|(submin))
 #define DRIVER_NAME "HP CISS Driver (v 3.6.14)"
@@ -1152,6 +1155,163 @@ #endif
 			kfree(ioc);
 			return status;
 		}
+	case SG_IO: {
+		struct sg_io_hdr hdr;
+		CommandList_struct *c;
+		char *buff = NULL;
+		u64bit temp64;
+		unsigned long flags;
+		DECLARE_COMPLETION_ONSTACK(wait);
+
+		if (!capable(CAP_SYS_RAWIO))
+			return -EPERM;
+
+		if (copy_from_user(&hdr, argp, sizeof(hdr)))
+			return -EFAULT;
+
+		if (hdr.interface_id != 'S')
+			return -EINVAL;
+
+		/* cciss only supports 16-byte commands */
+		if (hdr.cmd_len > 16)
+			return -EINVAL;
+
+		/* We don't support proper scatter-gather (yet) */
+		if (hdr.iovec_count)
+			return -EINVAL;
+
+		if ((hdr.dxfer_len < 1) &&
+		    (hdr.dxfer_direction != SG_DXFER_NONE))
+			return -EINVAL;
+
+		if (hdr.dxfer_len > 0) {
+			buff = kmalloc(hdr.dxfer_len, GFP_KERNEL);
+			if (buff == NULL)
+				return -EFAULT;
+		}
+		if ((hdr.dxfer_direction == SG_DXFER_TO_DEV) ||
+		    (hdr.dxfer_direction == SG_DXFER_TO_FROM_DEV)) {
+			/* Copy the data into the buffer we created */
+			if (copy_from_user (buff, hdr.dxferp,
+					    hdr.dxfer_len)) {
+				kfree(buff);
+				return -EFAULT;
+			}
+		} else
+			memset(buff, 0, hdr.dxfer_len);
+
+		if ((c = cmd_alloc(host, 0)) == NULL) {
+			kfree(buff);
+			return -ENOMEM;
+		}
+
+		/* Copy CDB */
+		if (copy_from_user(c->Request.CDB, hdr.cmdp, hdr.cmd_len))
+			return -EFAULT;
+
+		/* Fill in the command type */
+		c->cmd_type = CMD_IOCTL_PEND;
+		/* Fill in Command Header */
+		c->Header.ReplyQueue = 0;
+		if (hdr.dxfer_len > 0) {
+			c->Header.SGList = 1;
+			c->Header.SGTotal = 1;
+		} else {
+			c->Header.SGList = 0;
+			c->Header.SGTotal = 0;
+		}
+		/* Default to LUN the ioctl was directed to */
+		c->Header.LUN.LogDev.VolId = drv->LunID & 0x3FFFFFFF;
+		c->Header.LUN.LogDev.Mode = 0x01; /* Logical volume */
+		c->Header.Tag.lower = c->busaddr;
+
+		/* Fill in Request block */
+		c->Request.CDBLen = hdr.cmd_len;
+		c->Request.Type.Type = TYPE_CMD;
+		c->Request.Type.Attribute = ATTR_SIMPLE;
+		switch(hdr.dxfer_direction) {
+		    case SG_DXFER_NONE:
+			c->Request.Type.Direction = XFER_NONE;
+			break;
+		    case SG_DXFER_TO_DEV:
+			c->Request.Type.Direction = XFER_WRITE;
+			break;
+		    case SG_DXFER_FROM_DEV:
+			c->Request.Type.Direction = XFER_READ;
+			break;
+		    case SG_DXFER_TO_FROM_DEV:
+			c->Request.Type.Direction = XFER_RSVD;
+			break;
+		}
+		c->Request.Timeout = hdr.timeout;
+
+		/* Fill in the scatter gather information */
+		if (hdr.dxfer_len > 0) {
+			temp64.val = pci_map_single(host->pdev, buff,
+						    hdr.dxfer_len,
+						    PCI_DMA_BIDIRECTIONAL);
+			c->SG[0].Addr.lower = temp64.val32.lower;
+			c->SG[0].Addr.upper = temp64.val32.upper;
+			c->SG[0].Len = hdr.dxfer_len;
+			c->SG[0].Ext = 0;
+		}
+		c->waiting = &wait;
+
+		/* Put the request on the tail of the request queue */
+		spin_lock_irqsave(CCISS_LOCK(ctlr), flags);
+		addQ(&host->reqQ, c);
+		host->Qdepth++;
+		start_io(host);
+		spin_unlock_irqrestore(CCISS_LOCK(ctlr), flags);
+
+		wait_for_completion(&wait);
+
+		/* unlock the buffers from DMA */
+		temp64.val32.lower = c->SG[0].Addr.lower;
+		temp64.val32.upper = c->SG[0].Addr.upper;
+		pci_unmap_single(host->pdev, (dma_addr_t) temp64.val,
+				 hdr.dxfer_len,
+				 PCI_DMA_BIDIRECTIONAL);
+
+		/* Copy the error information out */
+		hdr.status = c->err_info->ScsiStatus;
+		if (c->err_info->SenseLen && hdr.mx_sb_len > 0) {
+			int sense_len = c->err_info->SenseLen;
+
+			if (sense_len > hdr.mx_sb_len)
+				sense_len = hdr.mx_sb_len;
+
+			if (copy_to_user(hdr.sbp, c->err_info->SenseInfo,
+					 sense_len)) {
+				kfree(buff);
+				cmd_free(host, c, 0);
+				return -EFAULT;
+			}
+			hdr.sb_len_wr = sense_len;
+		}
+		hdr.resid = c->err_info->ResidualCnt;
+		/* Copy out the header */
+		if (copy_to_user(argp, &hdr, sizeof(hdr))) {
+			kfree(buff);
+			cmd_free(host, c, 0);
+			return -EFAULT;
+		}
+
+		if ((hdr.dxfer_direction == SG_DXFER_FROM_DEV) ||
+		    (hdr.dxfer_direction == SG_DXFER_TO_FROM_DEV)) {
+			/* Copy the data out to the buffer we created */
+			if (copy_to_user
+			    (hdr.dxferp, buff, hdr.dxfer_len)) {
+				kfree(buff);
+				cmd_free(host, c, 0);
+				return -EFAULT;
+			}
+		}
+
+		kfree(buff);
+		cmd_free(host, c, 0);
+		return 0;
+		}
 	default:
 		return -ENOTTY;
 	}