Split declarations/definitions in drm_scatter.h into drm_sg.h/drm_sg_tmp.h

    respectively. Splited the work out of the ioctls and renamed (with the
    _ioctl prefix). Added some more documentation. Did the same for
    drm_sgpsupport.h.

16 files changed, 565 insertions, 311 deletions

diff --git a/linux/drmP.h b/linux/drmP.h
index 5626e4ff..d927e890 100644
--- a/linux/drmP.h
+++ b/linux/drmP.h
@@ -86,7 +86,6 @@
 
 #include "drm_os_linux.h"
 
-
 /***********************************************************************/
 /** \name DRM template customization defaults */
 /*@{*/
@@ -121,6 +120,12 @@
 /*@}*/
 
 
+typedef struct drm_device drm_device_t;
+
+#include "drm_agp.h"
+#include "drm_sg.h"
+
+
 /***********************************************************************/
 /** \name Begin the DRM... */
 /*@{*/
@@ -575,48 +580,6 @@ typedef struct drm_device_dma {
 	/*@}*/
 } drm_device_dma_t;
 
-#if __REALLY_HAVE_AGP
-/** 
- * AGP memory entry.  Stored as a doubly linked list.
- */
-typedef struct drm_agp_mem {
-	unsigned long      handle;	/**< handle */
-	agp_memory         *memory;	
-	unsigned long      bound;	/**< address */
-	int                pages;
-	struct drm_agp_mem *prev;	/**< previous entry */
-	struct drm_agp_mem *next;	/**< next entry */
-} drm_agp_mem_t;
-
-/**
- * AGP data.
- *
- * \sa DRM(agp_init)() and drm_device::agp.
- */
-typedef struct drm_agp_head {
-	agp_kern_info      agp_info;	/**< AGP device information */
-	drm_agp_mem_t      *memory;	/**< memory entries */
-	unsigned long      mode;	/**< AGP mode */
-	int                enabled;	/**< whether the AGP bus as been enabled */
-	int                acquired;	/**< whether the AGP device has been acquired */
-	unsigned long      base;
-   	int 		   agp_mtrr;
-	int		   cant_use_aperture;
-	unsigned long	   page_mask;
-} drm_agp_head_t;
-#endif
-
-/**
- * Scatter-gather memory.
- */
-typedef struct drm_sg_mem {
-	unsigned long   handle;
-	void            *virtual;
-	int             pages;
-	struct page     **pagelist;
-	dma_addr_t	*busaddr;
-} drm_sg_mem_t;
-
 typedef struct drm_sigdata {
 	int           context;
 	drm_hw_lock_t *lock;
@@ -646,7 +609,7 @@ typedef struct drm_vbl_sig {
 /**
  * DRM device structure.
  */
-typedef struct drm_device {
+struct drm_device {
 	const char	  *name;	/**< Simple driver name */
 	char		  *unique;	/**< Unique identifier: e.g., busid */
 	int		  unique_len;	/**< Length of unique field */
@@ -757,11 +720,12 @@ typedef struct drm_device {
 #endif
 #endif
 	drm_sg_mem_t      *sg;  /**< Scatter gather memory */
+
 	unsigned long     *ctx_bitmap;	/**< context bitmap */
 	void		  *dev_private; /**< device private data */
 	drm_sigdata_t     sigdata; /**< For block_all_signals */
 	sigset_t          sigmask;
-} drm_device_t;
+};
 
 
 /******************************************************************/
@@ -830,10 +794,10 @@ extern void	     *DRM(ioremap_nocache)(unsigned long offset, unsigned long size,
 extern void	     DRM(ioremapfree)(void *pt, unsigned long size, drm_device_t *dev);
 
 #if __REALLY_HAVE_AGP
-extern agp_memory    *DRM(alloc_agp)(int pages, u32 type);
-extern int           DRM(free_agp)(agp_memory *handle, int pages);
-extern int           DRM(bind_agp)(agp_memory *handle, unsigned int start);
-extern int           DRM(unbind_agp)(agp_memory *handle);
+extern agp_memory    *DRM(agp_alloc)(int pages, u32 type);
+extern int           DRM(agp_free)(agp_memory *handle, int pages);
+extern int           DRM(agp_bind)(agp_memory *handle, unsigned int start);
+extern int           DRM(agp_unbind)(agp_memory *handle);
 #endif
 
 				/* Misc. IOCTL support (drm_ioctl.h) */
@@ -956,32 +920,6 @@ extern void          DRM(dma_immediate_bh)( void *dev );
 
 #endif /* __HAVE_DMA */
 
-#if __REALLY_HAVE_AGP
-				/* AGP/GART support (drm_agpsupport.h) */
-extern drm_agp_head_t *DRM(agp_init)(void);
-extern void           DRM(agp_uninit)(void);
-extern int            DRM(agp_acquire)(struct inode *inode, struct file *filp,
-				       unsigned int cmd, unsigned long arg);
-extern void           DRM(agp_do_release)(void);
-extern int            DRM(agp_release)(struct inode *inode, struct file *filp,
-				       unsigned int cmd, unsigned long arg);
-extern int            DRM(agp_enable)(struct inode *inode, struct file *filp,
-				      unsigned int cmd, unsigned long arg);
-extern int            DRM(agp_info)(struct inode *inode, struct file *filp,
-				    unsigned int cmd, unsigned long arg);
-extern int            DRM(agp_alloc)(struct inode *inode, struct file *filp,
-				     unsigned int cmd, unsigned long arg);
-extern int            DRM(agp_free)(struct inode *inode, struct file *filp,
-				    unsigned int cmd, unsigned long arg);
-extern int            DRM(agp_unbind)(struct inode *inode, struct file *filp,
-				      unsigned int cmd, unsigned long arg);
-extern int            DRM(agp_bind)(struct inode *inode, struct file *filp,
-				    unsigned int cmd, unsigned long arg);
-extern agp_memory     *DRM(agp_allocate_memory)(size_t pages, u32 type);
-extern int            DRM(agp_free_memory)(agp_memory *handle);
-extern int            DRM(agp_bind_memory)(agp_memory *handle, off_t start);
-extern int            DRM(agp_unbind_memory)(agp_memory *handle);
-#endif
 
 				/* Stub support (drm_stub.h) */
 int                   DRM(stub_register)(const char *name,
@@ -998,15 +936,6 @@ extern int            DRM(proc_cleanup)(int minor,
 					struct proc_dir_entry *root,
 					struct proc_dir_entry *dev_root);
 
-#if __HAVE_SG
-				/* Scatter Gather Support (drm_scatter.h) */
-extern void           DRM(sg_cleanup)(drm_sg_mem_t *entry);
-extern int            DRM(sg_alloc)(struct inode *inode, struct file *filp,
-				    unsigned int cmd, unsigned long arg);
-extern int            DRM(sg_free)(struct inode *inode, struct file *filp,
-				   unsigned int cmd, unsigned long arg);
-#endif
-
                                /* ATI PCIGART support (ati_pcigart.h) */
 extern int            DRM(ati_pcigart_init)(drm_device_t *dev,
 					    unsigned long *addr,
diff --git a/linux/drm_agp.h b/linux/drm_agp.h
new file mode 100644
index 00000000..27c2b29f
--- /dev/null
+++ b/linux/drm_agp.h
@@ -0,0 +1,95 @@
+/**
+ * \file drm_agp.h 
+ * DRM support for AGP/GART backend
+ *    
+ * \author Rickard E. (Rik) Faith <faith@valinux.com>
+ * \author Gareth Hughes <gareth@valinux.com>
+ */
+
+/*
+ * Copyright 1999 Precision Insight, Inc., Cedar Park, Texas.
+ * Copyright 2000 VA Linux Systems, Inc., Sunnyvale, California.
+ * All Rights Reserved.
+ *
+ * Permission is hereby granted, free of charge, to any person obtaining a
+ * copy of this software and associated documentation files (the "Software"),
+ * to deal in the Software without restriction, including without limitation
+ * the rights to use, copy, modify, merge, publish, distribute, sublicense,
+ * and/or sell copies of the Software, and to permit persons to whom the
+ * Software is furnished to do so, subject to the following conditions:
+ *
+ * The above copyright notice and this permission notice (including the next
+ * paragraph) shall be included in all copies or substantial portions of the
+ * Software.
+ *
+ * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
+ * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
+ * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT.  IN NO EVENT SHALL
+ * VA LINUX SYSTEMS AND/OR ITS SUPPLIERS BE LIABLE FOR ANY CLAIM, DAMAGES OR
+ * OTHER LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE,
+ * ARISING FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR
+ * OTHER DEALINGS IN THE SOFTWARE.
+ */
+
+#ifndef _DRM_AGP_H_
+#define _DRM_AGP_H_
+
+
+/** 
+ * AGP memory entry.  Stored as a doubly linked list.
+ */
+typedef struct drm_agp_mem {
+	unsigned long      handle;	/**< handle */
+	agp_memory         *memory;	
+	unsigned long      bound;	/**< address */
+	int                pages;
+	struct drm_agp_mem *prev;	/**< previous entry */
+	struct drm_agp_mem *next;	/**< next entry */
+} drm_agp_mem_t;
+
+/**
+ * AGP data.
+ *
+ * \sa DRM(agp_init)() and drm_device::agp.
+ */
+typedef struct drm_agp_head {
+	agp_kern_info      agp_info;	/**< AGP device information */
+	drm_agp_mem_t      *memory;	/**< memory entries */
+	unsigned long      mode;	/**< AGP mode */
+	int                enabled;	/**< whether the AGP bus as been enabled */
+	int                acquired;	/**< whether the AGP device has been acquired */
+	unsigned long      base;
+   	int 		   agp_mtrr;
+	int		   cant_use_aperture;
+	unsigned long	   page_mask;
+} drm_agp_head_t;
+
+
+/** \name Prototypes */
+/*@{*/
+
+extern int DRM(agp_acquire)(void);
+extern void DRM(agp_release)(void);
+extern void DRM(agp_enable)(unsigned mode);
+extern agp_memory *DRM(agp_allocate_memory)(size_t pages, u32 type);
+extern int DRM(agp_free_memory)(agp_memory *handle);
+extern int DRM(agp_bind_memory)(agp_memory *handle, off_t start);
+extern int DRM(agp_unbind_memory)(agp_memory *handle);
+
+extern int DRM(agp_acquire_ioctl)(struct inode *inode, struct file *filp, unsigned int cmd, unsigned long arg);
+extern int DRM(agp_release_ioctl)(struct inode *inode, struct file *filp, unsigned int cmd, unsigned long arg);
+extern int DRM(agp_enable_ioctl)(struct inode *inode, struct file *filp, unsigned int cmd, unsigned long arg);
+extern int DRM(agp_info_ioctl)(struct inode *inode, struct file *filp, unsigned int cmd, unsigned long arg);
+extern int DRM(agp_alloc_ioctl)(struct inode *inode, struct file *filp, unsigned int cmd, unsigned long arg);
+extern int DRM(agp_free_ioctl)(struct inode *inode, struct file *filp, unsigned int cmd, unsigned long arg);
+extern int DRM(agp_bind_ioctl)(struct inode *inode, struct file *filp, unsigned int cmd, unsigned long arg);
+extern int DRM(agp_unbind_ioctl)(struct inode *inode, struct file *filp, unsigned int cmd, unsigned long arg);
+
+extern void DRM(agp_init)(void);
+extern void DRM(agp_cleanup)(void);
+extern void DRM(agp_init_dev)(drm_device_t *dev);
+extern void DRM(agp_cleanup_dev)(drm_device_t *dev);
+
+/*@}*/
+
+#endif
diff --git a/linux/drm_agpsupport.h b/linux/drm_agp_tmp.h
index 81850593..4b52ed4f 100644
--- a/linux/drm_agpsupport.h
+++ b/linux/drm_agp_tmp.h
@@ -1,5 +1,5 @@
 /**
- * \file drm_agpsupport.h 
+ * \file drm_agp_tmp.h 
  * DRM support for AGP/GART backend
  *    
  * \author Rickard E. (Rik) Faith <faith@valinux.com>
@@ -31,62 +31,117 @@
  * OTHER DEALINGS IN THE SOFTWARE.
  */
 
+
+
+#if __REALLY_HAVE_AGP
+
 #define __NO_VERSION__
 #include "drmP.h"
 #include <linux/module.h>
 
-#if __REALLY_HAVE_AGP
 
+/**
+ * Pointer to the drm_agp_t structure made available by the AGPGART module.
+ */
+static const drm_agp_t *drm_agp = NULL;
 
-#define DRM_AGP_GET (drm_agp_t *)inter_module_get("drm_agp")
-#define DRM_AGP_PUT inter_module_put("drm_agp")
+
+/**********************************************************************/
+/** \name drm_agp wrappers
+ *
+ * These functions are thin wrappers around the respective methods in drm_agp
+ * which are exposed by the AGPGART module.
+ *
+ * \todo Put these in a header inline.
+ */
 
 /**
- * Pointer to the drm_agp_t structure made available by the agpgart module.
+ * Acquire the AGP device.
  */
-static const drm_agp_t *drm_agp = NULL;
+int DRM(agp_acquire)(void)
+{
+	return drm_agp->acquire();
+}
 
 /**
- * AGP information ioctl.
- *
- * \param inode device inode.
- * \param filp file pointer.
- * \param cmd command.
- * \param arg pointer to a (output) drm_agp_info structure.
- * \return zero on success or a negative number on failure.
+ * Release the AGP device.
+ */
+void DRM(agp_release)(void)
+{
+	if (drm_agp->release)
+		drm_agp->release();
+}
+
+/**
+ * Enable the AGP bus.
+ */
+void DRM(agp_enable)(unsigned mode)
+{
+	if (drm_agp->enable)
+		drm_agp->enable(mode);
+}
+
+/** 
+ * Allocate AGP memory.
+ * 
+ * Not meant to be called directly.  Use agp_alloc() instead, which can provide
+ * some debugging features.
+ */
+agp_memory *DRM(agp_allocate_memory)(size_t pages, u32 type)
+{
+	if (!drm_agp->allocate_memory) 
+		return NULL;
+	return drm_agp->allocate_memory(pages, type);
+}
+
+/** 
+ * Free AGP memory.
+ * 
+ * Not meant to be called directly.  Use agp_free() instead, which can provide
+ * some debugging features.
+ */
+int DRM(agp_free_memory)(agp_memory *handle)
+{
+	if (!handle || !drm_agp->free_memory) 
+		return 0;
+	drm_agp->free_memory(handle);
+	return 1;
+}
+
+/** 
+ * Bind AGP memory.
  *
- * Verifies the AGP device has been initialized and acquired and fills in the
- * drm_agp_info structure with the information in drm_agp_head::agp_info.
+ * Not meant to be called directly.  Use agp_bind() instead, which can provide
+ * some debugging features.
  */
-int DRM(agp_info)(struct inode *inode, struct file *filp,
-		  unsigned int cmd, unsigned long arg)
+int DRM(agp_bind_memory)(agp_memory *handle, off_t start)
 {
-	drm_file_t	 *priv	 = filp->private_data;
-	drm_device_t	 *dev	 = priv->dev;
-	agp_kern_info    *kern;
-	drm_agp_info_t   info;
+	if (!handle || !drm_agp->bind_memory) 
+		return -EINVAL;
+	return drm_agp->bind_memory(handle, start);
+}
 
-	if (!dev->agp || !dev->agp->acquired || !drm_agp->copy_info)
+/** 
+ * Bind AGP memory.
+ *
+ * Not meant to be called directly.  Use agp_unbind() instead, which can provide
+ * some debugging features.
+ */
+int DRM(agp_unbind_memory)(agp_memory *handle)
+{
+	if (!handle || !drm_agp->unbind_memory)
 		return -EINVAL;
+	return drm_agp->unbind_memory(handle);
+}
 
-	kern                   = &dev->agp->agp_info;
-	info.agp_version_major = kern->version.major;
-	info.agp_version_minor = kern->version.minor;
-	info.mode              = kern->mode;
-	info.aperture_base     = kern->aper_base;
-	info.aperture_size     = kern->aper_size * 1024 * 1024;
-	info.memory_allowed    = kern->max_memory << PAGE_SHIFT;
-	info.memory_used       = kern->current_memory << PAGE_SHIFT;
-	info.id_vendor         = kern->device->vendor;
-	info.id_device         = kern->device->device;
+/**@}*/
 
-	if (copy_to_user((drm_agp_info_t *)arg, &info, sizeof(info)))
-		return -EFAULT;
-	return 0;
-}
+
+/**********************************************************************/
+/** \name Ioctl's */
 
 /**
- * Acquire the AGP device (ioctl).
+ * Acquire the AGP device.
  *
  * \param inode device inode.
  * \param filp file pointer.
@@ -95,9 +150,9 @@ int DRM(agp_info)(struct inode *inode, struct file *filp,
  * \return zero on success or a negative number on failure. 
  *
  * Verifies the AGP device hasn't been acquired before and calls
- * drm_agp->acquire().
+ * drm_acquire().
  */
-int DRM(agp_acquire)(struct inode *inode, struct file *filp,
+int DRM(agp_acquire_ioctl)(struct inode *inode, struct file *filp,
 		     unsigned int cmd, unsigned long arg)
 {
 	drm_file_t	 *priv	 = filp->private_data;
@@ -106,13 +161,13 @@ int DRM(agp_acquire)(struct inode *inode, struct file *filp,
 
 	if (!dev->agp || dev->agp->acquired || !drm_agp->acquire)
 		return -EINVAL;
-	if ((retcode = drm_agp->acquire())) return retcode;
+	if ((retcode = DRM(agp_acquire)())) return retcode;
 	dev->agp->acquired = 1;
 	return 0;
 }
 
 /**
- * Release the AGP device (ioctl).
+ * Release the AGP device.
  *
  * \param inode device inode.
  * \param filp file pointer.
@@ -122,7 +177,7 @@ int DRM(agp_acquire)(struct inode *inode, struct file *filp,
  *
  * Verifies the AGP device has been acquired and calls drm_agp->release().
  */
-int DRM(agp_release)(struct inode *inode, struct file *filp,
+int DRM(agp_release_ioctl)(struct inode *inode, struct file *filp,
 		     unsigned int cmd, unsigned long arg)
 {
 	drm_file_t	 *priv	 = filp->private_data;
@@ -137,13 +192,42 @@ int DRM(agp_release)(struct inode *inode, struct file *filp,
 }
 
 /**
- * Release the AGP device.
+ * Get AGP information.
+ *
+ * \param inode device inode.
+ * \param filp file pointer.
+ * \param cmd command.
+ * \param arg pointer to an (output) drm_agp_info structure.
+ * \return zero on success or a negative number on failure.
  *
- * Calls drm_agp->release().
+ * Verifies the AGP device has been initialized and acquired and fills in the
+ * drm_agp_info structure with the information in drm_agp_head::agp_info.
  */
-void DRM(agp_do_release)(void)
+int DRM(agp_info_ioctl)(struct inode *inode, struct file *filp,
+		  unsigned int cmd, unsigned long arg)
 {
-	if (drm_agp->release) drm_agp->release();
+	drm_file_t	 *priv	 = filp->private_data;
+	drm_device_t	 *dev	 = priv->dev;
+	agp_kern_info    *kern;
+	drm_agp_info_t   info;
+
+	if (!dev->agp || !dev->agp->acquired || !drm_agp->copy_info)
+		return -EINVAL;
+
+	kern                   = &dev->agp->agp_info;
+	info.agp_version_major = kern->version.major;
+	info.agp_version_minor = kern->version.minor;
+	info.mode              = kern->mode;
+	info.aperture_base     = kern->aper_base;
+	info.aperture_size     = kern->aper_size * 1024 * 1024;
+	info.memory_allowed    = kern->max_memory << PAGE_SHIFT;
+	info.memory_used       = kern->current_memory << PAGE_SHIFT;
+	info.id_vendor         = kern->device->vendor;
+	info.id_device         = kern->device->device;
+
+	if (copy_to_user((drm_agp_info_t *)arg, &info, sizeof(info)))
+		return -EFAULT;
+	return 0;
 }
 
 /**
@@ -155,10 +239,10 @@ void DRM(agp_do_release)(void)
  * \param arg pointer to a drm_agp_mode structure.
  * \return zero on success or a negative number on failure.
  *
- * Verifies the AGP device has been acquired but not enabled, and calls
- * drm_agp->enable().
+ * Verifies the AGP device has been acquired, and calls
+ * agp_enable().
  */
-int DRM(agp_enable)(struct inode *inode, struct file *filp,
+int DRM(agp_enable_ioctl)(struct inode *inode, struct file *filp,
 		    unsigned int cmd, unsigned long arg)
 {
 	drm_file_t	 *priv	 = filp->private_data;
@@ -172,7 +256,7 @@ int DRM(agp_enable)(struct inode *inode, struct file *filp,
 		return -EFAULT;
 
 	dev->agp->mode    = mode.mode;
-	drm_agp->enable(mode.mode);
+	DRM(agp_enable)(mode.mode);
 	dev->agp->base    = dev->agp->agp_info.aper_base;
 	dev->agp->enabled = 1;
 	return 0;
@@ -190,7 +274,7 @@ int DRM(agp_enable)(struct inode *inode, struct file *filp,
  * Verifies the AGP device is present and has been acquired, allocates the
  * memory via alloc_agp() and creates a drm_agp_mem entry for it.
  */
-int DRM(agp_alloc)(struct inode *inode, struct file *filp,
+int DRM(agp_alloc_ioctl)(struct inode *inode, struct file *filp,
 		   unsigned int cmd, unsigned long arg)
 {
 	drm_file_t	 *priv	 = filp->private_data;
@@ -212,7 +296,7 @@ int DRM(agp_alloc)(struct inode *inode, struct file *filp,
 	pages = (request.size + PAGE_SIZE - 1) / PAGE_SIZE;
 	type = (u32) request.type;
 
-	if (!(memory = DRM(alloc_agp)(pages, type))) {
+	if (!(memory = DRM(agp_alloc)(pages, type))) {
 		DRM(free)(entry, sizeof(*entry), DRM_MEM_AGPLISTS);
 		return -ENOMEM;
 	}
@@ -232,7 +316,7 @@ int DRM(agp_alloc)(struct inode *inode, struct file *filp,
 	if (copy_to_user((drm_agp_buffer_t *)arg, &request, sizeof(request))) {
 		dev->agp->memory       = entry->next;
 		dev->agp->memory->prev = NULL;
-		DRM(free_agp)(memory, pages);
+		DRM(agp_free)(memory, pages);
 		DRM(free)(entry, sizeof(*entry), DRM_MEM_AGPLISTS);
 		return -EFAULT;
 	}
@@ -260,7 +344,7 @@ static drm_agp_mem_t *DRM(agp_lookup_entry)(drm_device_t *dev,
 }
 
 /**
- * Unbind AGP memory from the GATT (ioctl).
+ * Unbind AGP memory from the GATT.
  *
  * \param inode device inode.
  * \param filp file pointer.
@@ -271,7 +355,7 @@ static drm_agp_mem_t *DRM(agp_lookup_entry)(drm_device_t *dev,
  * Verifies the AGP device is present and acquired, looks-up the AGP memory
  * entry and passes it to the unbind_agp() function.
  */
-int DRM(agp_unbind)(struct inode *inode, struct file *filp,
+int DRM(agp_unbind_ioctl)(struct inode *inode, struct file *filp,
 		    unsigned int cmd, unsigned long arg)
 {
 	drm_file_t	  *priv	 = filp->private_data;
@@ -286,14 +370,14 @@ int DRM(agp_unbind)(struct inode *inode, struct file *filp,
 	if (!(entry = DRM(agp_lookup_entry)(dev, request.handle)))
 		return -EINVAL;
 	if (!entry->bound) return -EINVAL;
-	ret = DRM(unbind_agp)(entry->memory);
+	ret = DRM(agp_unbind)(entry->memory);
 	if (ret == 0)
 	    entry->bound = 0;
 	return ret;
 }
 
 /**
- * Bind AGP memory into the GATT (ioctl)
+ * Bind AGP memory into the GATT
  *
  * \param inode device inode.
  * \param filp file pointer.
@@ -305,7 +389,7 @@ int DRM(agp_unbind)(struct inode *inode, struct file *filp,
  * is currently bound into the GATT. Looks-up the AGP memory entry and passes
  * it to bind_agp() function.
  */
-int DRM(agp_bind)(struct inode *inode, struct file *filp,
+int DRM(agp_bind_ioctl)(struct inode *inode, struct file *filp,
 		  unsigned int cmd, unsigned long arg)
 {
 	drm_file_t	  *priv	 = filp->private_data;
@@ -323,7 +407,7 @@ int DRM(agp_bind)(struct inode *inode, struct file *filp,
 		return -EINVAL;
 	if (entry->bound) return -EINVAL;
 	page = (request.offset + PAGE_SIZE - 1) / PAGE_SIZE;
-	if ((retcode = DRM(bind_agp)(entry->memory, page))) return retcode;
+	if ((retcode = DRM(agp_bind)(entry->memory, page))) return retcode;
 	entry->bound = dev->agp->base + (page << PAGE_SHIFT);
 	DRM_DEBUG("base = 0x%lx entry->bound = 0x%lx\n",
 		  dev->agp->base, entry->bound);
@@ -331,7 +415,7 @@ int DRM(agp_bind)(struct inode *inode, struct file *filp,
 }
 
 /**
- * Free AGP memory (ioctl).
+ * Free AGP memory.
  *
  * \param inode device inode.
  * \param filp file pointer.
@@ -344,7 +428,7 @@ int DRM(agp_bind)(struct inode *inode, struct file *filp,
  * unbind_agp(). Frees it via free_agp() as well as the entry itself
  * and unlinks from the doubly linked list it's inserted in.
  */
-int DRM(agp_free)(struct inode *inode, struct file *filp,
+int DRM(agp_free_ioctl)(struct inode *inode, struct file *filp,
 		  unsigned int cmd, unsigned long arg)
 {
 	drm_file_t	 *priv	 = filp->private_data;
@@ -357,95 +441,113 @@ int DRM(agp_free)(struct inode *inode, struct file *filp,
 		return -EFAULT;
 	if (!(entry = DRM(agp_lookup_entry)(dev, request.handle)))
 		return -EINVAL;
-	if (entry->bound) DRM(unbind_agp)(entry->memory);
+	if (entry->bound) DRM(agp_unbind)(entry->memory);
 
 	if (entry->prev) entry->prev->next = entry->next;
 	else             dev->agp->memory  = entry->next;
 	if (entry->next) entry->next->prev = entry->prev;
-	DRM(free_agp)(entry->memory, entry->pages);
+	DRM(agp_free)(entry->memory, entry->pages);
 	DRM(free)(entry, sizeof(*entry), DRM_MEM_AGPLISTS);
 	return 0;
 }
 
+/*@}*/
+
+
+/**********************************************************************/
+/** \name Initialization and cleanup */
+/*@{*/
+
 /**
- * Initialize the AGP resources.
- *
- * \return pointer to a drm_agp_head structure.
+ * Initialize the global AGP resources.
  *
  * Gets the drm_agp_t structure which is made available by the agpgart module
- * via the inter_module_* functions. Creates and initializes a drm_agp_head
- * structure.
+ * via the inter_module_* functions.
  */
-drm_agp_head_t *DRM(agp_init)(void)
+void DRM(agp_init)(void)
 {
-	drm_agp_head_t *head         = NULL;
-
-	drm_agp = DRM_AGP_GET;
-	if (drm_agp) {
-		if (!(head = DRM(alloc)(sizeof(*head), DRM_MEM_AGPLISTS)))
-			return NULL;
-		memset((void *)head, 0, sizeof(*head));
-		drm_agp->copy_info(&head->agp_info);
-		if (head->agp_info.chipset == NOT_SUPPORTED) {
-			DRM(free)(head, sizeof(*head), DRM_MEM_AGPLISTS);
-			return NULL;
-		}
-		head->memory = NULL;
-#if LINUX_VERSION_CODE <= 0x020408
-		head->cant_use_aperture = 0;
-		head->page_mask = ~(0xfff);
-#else
-		head->cant_use_aperture = head->agp_info.cant_use_aperture;
-		head->page_mask = head->agp_info.page_mask;
-#endif
-
-		DRM_INFO("AGP %d.%d aperture @ 0x%08lx %ZuMB\n",
-			 head->agp_info.version.major,
-			 head->agp_info.version.minor,
-			 head->agp_info.aper_base,
-			 head->agp_info.aper_size);
-	}
-	return head;
+	drm_agp = (drm_agp_t *)inter_module_get("drm_agp");
 }
 
 /**
- * Free the AGP resources.
+ * Free the global AGP resources.
  *
  * Releases the pointer in ::drm_agp.
  */
-void DRM(agp_uninit)(void)
+void DRM(agp_cleanup)(void)
 {
-	DRM_AGP_PUT;
-	drm_agp = NULL;
+	if (drm_agp) {
+		inter_module_put("drm_agp");
+		drm_agp = NULL;
+	}
 }
 
-/** Calls drm_agp->allocate_memory() */
-agp_memory *DRM(agp_allocate_memory)(size_t pages, u32 type)
+/**
+ * Initialize the device AGP resources.
+ *
+ * Creates and initializes a drm_agp_head structure in drm_device_t::agp.
+ */
+void DRM(agp_init_dev)(drm_device_t *dev)
 {
-	if (!drm_agp->allocate_memory) return NULL;
-	return drm_agp->allocate_memory(pages, type);
-}
+	drm_agp_head_t *head         = NULL;
 
-/** Calls drm_agp->free_memory() */
-int DRM(agp_free_memory)(agp_memory *handle)
-{
-	if (!handle || !drm_agp->free_memory) return 0;
-	drm_agp->free_memory(handle);
-	return 1;
-}
+	if (!(head = DRM(alloc)(sizeof(*head), DRM_MEM_AGPLISTS)))
+		return;
 
-/** Calls drm_agp->bind_memory() */
-int DRM(agp_bind_memory)(agp_memory *handle, off_t start)
-{
-	if (!handle || !drm_agp->bind_memory) return -EINVAL;
-	return drm_agp->bind_memory(handle, start);
+	memset((void *)head, 0, sizeof(*head));
+	drm_agp->copy_info(&head->agp_info);
+	if (head->agp_info.chipset == NOT_SUPPORTED) {
+		DRM(free)(head, sizeof(*head), DRM_MEM_AGPLISTS);
+	}
+	head->memory = NULL;
+#if LINUX_VERSION_CODE <= 0x020408
+	head->cant_use_aperture = 0;
+	head->page_mask = ~(0xfff);
+#else
+	head->cant_use_aperture = head->agp_info.cant_use_aperture;
+	head->page_mask = head->agp_info.page_mask;
+#endif
+
+	DRM_INFO("AGP %d.%d aperture @ 0x%08lx %ZuMB\n",
+		 head->agp_info.version.major,
+		 head->agp_info.version.minor,
+		 head->agp_info.aper_base,
+		 head->agp_info.aper_size);
+
+	dev->agp = head;
 }
 
-/** Calls drm_agp->unbind_memory() */
-int DRM(agp_unbind_memory)(agp_memory *handle)
+/**
+ * Free the device AGP resources.
+ */
+void DRM(agp_cleanup_dev)(drm_device_t *dev)
 {
-	if (!handle || !drm_agp->unbind_memory) return -EINVAL;
-	return drm_agp->unbind_memory(handle);
+	if ( dev->agp ) {
+		drm_agp_mem_t *entry;
+		drm_agp_mem_t *nexte;
+
+				/* Remove AGP resources, but leave dev->agp
+                                   intact until drv_cleanup is called. */
+		for ( entry = dev->agp->memory ; entry ; entry = nexte ) {
+			nexte = entry->next;
+			if ( entry->bound ) DRM(agp_unbind)( entry->memory );
+			DRM(agp_free)( entry->memory, entry->pages );
+			DRM(free)( entry, sizeof(*entry), DRM_MEM_AGPLISTS );
+		}
+		dev->agp->memory = NULL;
+
+		if ( dev->agp->acquired )
+			DRM(agp_release)();
+
+		dev->agp->acquired = 0;
+		dev->agp->enabled  = 0;
+
+		DRM(free)( dev->agp, sizeof(*dev->agp), DRM_MEM_AGPLISTS );
+		dev->agp = NULL;
+	}
 }
 
+/*@}*/
+
+
 #endif /* __REALLY_HAVE_AGP */
diff --git a/linux/drm_bufs.h b/linux/drm_bufs.h
index 77573709..f42fabef 100644
--- a/linux/drm_bufs.h
+++ b/linux/drm_bufs.h
@@ -174,6 +174,8 @@ int DRM(addmap)( struct inode *inode, struct file *filp,
 		map->mtrr   = dev->agp->agp_mtrr; /* for getmap */
 		break;
 #endif
+		
+#if __HAVE_SG
 	case _DRM_SCATTER_GATHER:
 		if (!dev->sg) {
 			DRM(free)(map, sizeof(*map), DRM_MEM_MAPS);
@@ -181,6 +183,7 @@ int DRM(addmap)( struct inode *inode, struct file *filp,
 		}
 		map->offset += dev->sg->handle;
 		break;
+#endif
 
 	default:
 		DRM(free)( map, sizeof(*map), DRM_MEM_MAPS );
diff --git a/linux/drm_drv.h b/linux/drm_drv.h
index 90c2d18b..5a4ab36e 100644
--- a/linux/drm_drv.h
+++ b/linux/drm_drv.h
@@ -225,19 +225,19 @@ static drm_ioctl_desc_t		  DRM(ioctls)[] = {
 #endif
 
 #if __REALLY_HAVE_AGP
-	[DRM_IOCTL_NR(DRM_IOCTL_AGP_ACQUIRE)]   = { DRM(agp_acquire), 1, 1 },
-	[DRM_IOCTL_NR(DRM_IOCTL_AGP_RELEASE)]   = { DRM(agp_release), 1, 1 },
-	[DRM_IOCTL_NR(DRM_IOCTL_AGP_ENABLE)]    = { DRM(agp_enable),  1, 1 },
-	[DRM_IOCTL_NR(DRM_IOCTL_AGP_INFO)]      = { DRM(agp_info),    1, 0 },
-	[DRM_IOCTL_NR(DRM_IOCTL_AGP_ALLOC)]     = { DRM(agp_alloc),   1, 1 },
-	[DRM_IOCTL_NR(DRM_IOCTL_AGP_FREE)]      = { DRM(agp_free),    1, 1 },
-	[DRM_IOCTL_NR(DRM_IOCTL_AGP_BIND)]      = { DRM(agp_bind),    1, 1 },
-	[DRM_IOCTL_NR(DRM_IOCTL_AGP_UNBIND)]    = { DRM(agp_unbind),  1, 1 },
+	[DRM_IOCTL_NR(DRM_IOCTL_AGP_ACQUIRE)]   = { DRM(agp_acquire_ioctl), 1, 1 },
+	[DRM_IOCTL_NR(DRM_IOCTL_AGP_RELEASE)]   = { DRM(agp_release_ioctl), 1, 1 },
+	[DRM_IOCTL_NR(DRM_IOCTL_AGP_ENABLE)]    = { DRM(agp_enable_ioctl),  1, 1 },
+	[DRM_IOCTL_NR(DRM_IOCTL_AGP_INFO)]      = { DRM(agp_info_ioctl), 1, 0 },
+	[DRM_IOCTL_NR(DRM_IOCTL_AGP_ALLOC)]     = { DRM(agp_alloc_ioctl), 1, 1 },
+	[DRM_IOCTL_NR(DRM_IOCTL_AGP_FREE)]      = { DRM(agp_free_ioctl), 1, 1 },
+	[DRM_IOCTL_NR(DRM_IOCTL_AGP_BIND)]      = { DRM(agp_bind_ioctl), 1, 1 },
+	[DRM_IOCTL_NR(DRM_IOCTL_AGP_UNBIND)]    = { DRM(agp_unbind_ioctl), 1, 1 },
 #endif
 
 #if __HAVE_SG
-	[DRM_IOCTL_NR(DRM_IOCTL_SG_ALLOC)]      = { DRM(sg_alloc),    1, 1 },
-	[DRM_IOCTL_NR(DRM_IOCTL_SG_FREE)]       = { DRM(sg_free),     1, 1 },
+	[DRM_IOCTL_NR(DRM_IOCTL_SG_ALLOC)]      = { DRM(sg_alloc_ioctl), 1, 1 },
+	[DRM_IOCTL_NR(DRM_IOCTL_SG_FREE)]       = { DRM(sg_free_ioctl), 1, 1 },
 #endif
 
 #if __HAVE_VBL_IRQ
@@ -416,29 +416,6 @@ static int DRM(takedown)( drm_device_t *dev )
 		dev->magiclist[i].head = dev->magiclist[i].tail = NULL;
 	}
 
-#if __REALLY_HAVE_AGP
-				/* Clear AGP information */
-	if ( dev->agp ) {
-		drm_agp_mem_t *entry;
-		drm_agp_mem_t *nexte;
-
-				/* Remove AGP resources, but leave dev->agp
-                                   intact until drv_cleanup is called. */
-		for ( entry = dev->agp->memory ; entry ; entry = nexte ) {
-			nexte = entry->next;
-			if ( entry->bound ) DRM(unbind_agp)( entry->memory );
-			DRM(free_agp)( entry->memory, entry->pages );
-			DRM(free)( entry, sizeof(*entry), DRM_MEM_AGPLISTS );
-		}
-		dev->agp->memory = NULL;
-
-		if ( dev->agp->acquired ) DRM(agp_do_release)();
-
-		dev->agp->acquired = 0;
-		dev->agp->enabled  = 0;
-	}
-#endif
-
 				/* Clear vma list (only built for debugging) */
 	if ( dev->vmalist ) {
 		for ( vma = dev->vmalist ; vma ; vma = vma_next ) {
@@ -486,10 +463,7 @@ static int DRM(takedown)( drm_device_t *dev )
 				 * isn't defined.
 				 */
 #if __HAVE_SG
-				if(dev->sg) {
-					DRM(sg_cleanup)(dev->sg);
-					dev->sg = NULL;
-				}
+				DRM(sg_cleanup)(dev);
 #endif
 				break;
 			}
@@ -618,6 +592,10 @@ static int __init drm_init( void )
 
 	DRM(mem_init)();
 
+#if __REALLY_HAVE_AGP
+	DRM(agp_init)();
+#endif
+		
 	for (i = 0; i < DRM(numdevs); i++) {
 		dev = &(DRM(device)[i]);
 		memset( (void *)dev, 0, sizeof(*dev) );
@@ -630,8 +608,9 @@ static int __init drm_init( void )
 		dev->name   = DRIVER_NAME;
 
 #if __REALLY_HAVE_AGP
-		dev->agp = DRM(agp_init)();
+		DRM(agp_init_dev)( dev );
 #if __MUST_HAVE_AGP
+		
 		if ( dev->agp == NULL ) {
 			DRM_ERROR( "Cannot initialize the agpgart module.\n" );
 			DRM(stub_unregister)(DRM(minor)[i]);
@@ -639,14 +618,12 @@ static int __init drm_init( void )
 			return -ENOMEM;
 		}
 #endif
-#if __REALLY_HAVE_MTRR
 		if (dev->agp)
 			dev->agp->agp_mtrr = mtrr_add( dev->agp->agp_info.aper_base,
 				       dev->agp->agp_info.aper_size*1024*1024,
 				       MTRR_TYPE_WRCOMB,
 				       1 );
 #endif
-#endif
 
 #if __HAVE_CTX_BITMAP
 		retcode = DRM(ctxbitmap_init)( dev );
@@ -712,13 +689,14 @@ static void __exit drm_cleanup( void )
 		DRM(takedown)( dev );
 
 #if __REALLY_HAVE_AGP
-		if ( dev->agp ) {
-			DRM(agp_uninit)();
-			DRM(free)( dev->agp, sizeof(*dev->agp), DRM_MEM_AGPLISTS );
-			dev->agp = NULL;
-		}
+		DRM(agp_cleanup_dev)( dev );
 #endif
 	}
+
+#if __REALLY_HAVE_AGP
+	DRM(agp_cleanup)();
+#endif
+
 	DRIVER_POSTCLEANUP();
 	kfree(DRM(minor));
 	kfree(DRM(device));
diff --git a/linux/drm_memory.h b/linux/drm_memory.h
index 2a969fcd..9999c213 100644
--- a/linux/drm_memory.h
+++ b/linux/drm_memory.h
@@ -332,27 +332,29 @@ void DRM(ioremapfree)(void *pt, unsigned long size, drm_device_t *dev)
 
 #if __REALLY_HAVE_AGP
 /** Wrapper around agp_allocate_memory() */
-agp_memory *DRM(alloc_agp)(int pages, u32 type)
+agp_memory *DRM(agp_alloc)(int pages, u32 type)
 {
 	return DRM(agp_allocate_memory)(pages, type);
 }
 
 /** Wrapper around agp_free_memory() */
-int DRM(free_agp)(agp_memory *handle, int pages)
+int DRM(agp_free)(agp_memory *handle, int pages)
 {
 	return DRM(agp_free_memory)(handle) ? 0 : -EINVAL;
 }
 
 /** Wrapper around agp_bind_memory() */
-int DRM(bind_agp)(agp_memory *handle, unsigned int start)
+int DRM(agp_bind)(agp_memory *handle, unsigned int start)
 {
 	return DRM(agp_bind_memory)(handle, start);
 }
 
 /** Wrapper around agp_unbind_memory() */
-int DRM(unbind_agp)(agp_memory *handle)
+int DRM(agp_unbind)(agp_memory *handle)
 {
 	return DRM(agp_unbind_memory)(handle);
 }
-#endif /* agp */
+#endif /* __REALLY_HAVE_AGP */
+
+
 #endif /* debug_memory */
diff --git a/linux/drm_memory_debug.h b/linux/drm_memory_debug.h
index 5cfff83a..860fc741 100644
--- a/linux/drm_memory_debug.h
+++ b/linux/drm_memory_debug.h
@@ -343,7 +343,7 @@ void DRM(ioremapfree)(void *pt, unsigned long size, drm_device_t *dev)
 
 #if __REALLY_HAVE_AGP
 
-agp_memory *DRM(alloc_agp)(int pages, u32 type)
+agp_memory *DRM(agp_alloc)(int pages, u32 type)
 {
 	agp_memory *handle;
 
@@ -366,7 +366,7 @@ agp_memory *DRM(alloc_agp)(int pages, u32 type)
 	return NULL;
 }
 
-int DRM(free_agp)(agp_memory *handle, int pages)
+int DRM(agp_free)(agp_memory *handle, int pages)
 {
 	int           alloc_count;
 	int           free_count;
@@ -395,7 +395,7 @@ int DRM(free_agp)(agp_memory *handle, int pages)
 	return retval;
 }
 
-int DRM(bind_agp)(agp_memory *handle, unsigned int start)
+int DRM(agp_bind)(agp_memory *handle, unsigned int start)
 {
 	int retcode = -EINVAL;
 
@@ -419,7 +419,7 @@ int DRM(bind_agp)(agp_memory *handle, unsigned int start)
 	return retcode;
 }
 
-int DRM(unbind_agp)(agp_memory *handle)
+int DRM(agp_unbind)(agp_memory *handle)
 {
 	int alloc_count;
 	int free_count;
diff --git a/linux/drm_sg.h b/linux/drm_sg.h
new file mode 100644
index 00000000..afd80ef0
--- /dev/null
+++ b/linux/drm_sg.h
@@ -0,0 +1,65 @@
+/**
+ * \file drm_sg.h 
+ * IOCTLs to manage scatter/gather memory
+ *
+ * \author Gareth Hughes <gareth@valinux.com>
+ */
+
+/*
+ * Copyright 2000 VA Linux Systems, Inc., Sunnyvale, California.
+ * All Rights Reserved.
+ *
+ * Permission is hereby granted, free of charge, to any person obtaining a
+ * copy of this software and associated documentation files (the "Software"),
+ * to deal in the Software without restriction, including without limitation
+ * the rights to use, copy, modify, merge, publish, distribute, sublicense,
+ * and/or sell copies of the Software, and to permit persons to whom the
+ * Software is furnished to do so, subject to the following conditions:
+ *
+ * The above copyright notice and this permission notice (including the next
+ * paragraph) shall be included in all copies or substantial portions of the
+ * Software.
+ *
+ * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
+ * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
+ * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT.  IN NO EVENT SHALL
+ * PRECISION INSIGHT AND/OR ITS SUPPLIERS BE LIABLE FOR ANY CLAIM, DAMAGES OR
+ * OTHER LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE,
+ * ARISING FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER
+ * DEALINGS IN THE SOFTWARE.
+ */
+
+
+#ifndef _DRM_SCATTER_H_
+#define _DRM_SCATTER_H_
+
+
+/**
+ * Scatter/gather memory entry.
+ *
+ * This structure is used by sg_alloc() sg_free() to store all the necessary
+ * information about a scatter/gather memory block.
+ * 
+ * Also one instance of this structure is used to hold the user-space
+ * allocation done via the sg_alloc_ioctl() and sg_free_ioctl() ioctl's.
+ */
+typedef struct drm_sg_mem {
+	unsigned long   handle;
+	void            *virtual;	/**< virtual address */
+	int             pages;
+	struct page     **pagelist;
+	dma_addr_t	*busaddr;	/**< bus address */
+} drm_sg_mem_t;
+
+
+/** \name Prototypes */
+/*@{*/
+extern void DRM(sg_free)( drm_sg_mem_t *entry );
+extern drm_sg_mem_t * DRM(sg_alloc)( unsigned long size );
+extern int DRM(sg_alloc_ioctl)(struct inode *inode, struct file *filp, unsigned int cmd, unsigned long arg);
+extern int DRM(sg_free_ioctl)(struct inode *inode, struct file *filp, unsigned int cmd, unsigned long arg);
+extern void DRM(sg_cleanup)(drm_device_t *dev);
+/*@}*/
+
+
+#endif
diff --git a/linux/drm_scatter.h b/linux/drm_sg_tmp.h
index 45a30fc3..95cb1fc7 100644
--- a/linux/drm_scatter.h
+++ b/linux/drm_sg_tmp.h
@@ -1,13 +1,11 @@
 /**
- * \file drm_scatter.h 
+ * \file drm_sg_tmp.h 
  * IOCTLs to manage scatter/gather memory
  *
  * \author Gareth Hughes <gareth@valinux.com>
  */
 
 /*
- * Created: Mon Dec 18 23:20:54 2000 by gareth@valinux.com
- *
  * Copyright 2000 VA Linux Systems, Inc., Sunnyvale, California.
  * All Rights Reserved.
  *
@@ -31,14 +29,29 @@
  * DEALINGS IN THE SOFTWARE.
  */
 
+
+#if __HAVE_SG
+
+
 #define __NO_VERSION__
 #include <linux/config.h>
 #include <linux/vmalloc.h>
 #include "drmP.h"
 
+
+/**
+ * Define to non-zero to verify that each page points to its virtual address,
+ * and vice versa, in sg_alloc().
+ */
 #define DEBUG_SCATTER 0
 
-void DRM(sg_cleanup)( drm_sg_mem_t *entry )
+
+/** 
+ * Free scatter/gather memory. 
+ *
+ * \param entry scatter/gather memory entry to free, as returned by sg_alloc().
+ */
+void DRM(sg_free)( drm_sg_mem_t *entry )
 {
 	struct page *page;
 	int i;
@@ -62,40 +75,34 @@ void DRM(sg_cleanup)( drm_sg_mem_t *entry )
 		   DRM_MEM_SGLISTS );
 }
 
-int DRM(sg_alloc)( struct inode *inode, struct file *filp,
-		   unsigned int cmd, unsigned long arg )
+/** 
+ * Allocate scatter/gather memory. 
+ *
+ * \param size size of memory to allocate.
+ * \return pointer to a drm_sg_mem structure on success or NULL on failure.
+ */
+drm_sg_mem_t * DRM(sg_alloc)( unsigned long size )
 {
-	drm_file_t *priv = filp->private_data;
-	drm_device_t *dev = priv->dev;
-	drm_scatter_gather_t request;
 	drm_sg_mem_t *entry;
 	unsigned long pages, i, j;
 
 	DRM_DEBUG( "%s\n", __FUNCTION__ );
 
-	if ( dev->sg )
-		return -EINVAL;
-
-	if ( copy_from_user( &request,
-			     (drm_scatter_gather_t *)arg,
-			     sizeof(request) ) )
-		return -EFAULT;
-
 	entry = DRM(alloc)( sizeof(*entry), DRM_MEM_SGLISTS );
 	if ( !entry )
-		return -ENOMEM;
+		return NULL;
 
    	memset( entry, 0, sizeof(*entry) );
 
-	pages = (request.size + PAGE_SIZE - 1) / PAGE_SIZE;
-	DRM_DEBUG( "sg size=%ld pages=%ld\n", request.size, pages );
+	pages = (size + PAGE_SIZE - 1) / PAGE_SIZE;
+	DRM_DEBUG( "sg size=%ld pages=%ld\n", size, pages );
 
 	entry->pages = pages;
 	entry->pagelist = DRM(alloc)( pages * sizeof(*entry->pagelist),
 				     DRM_MEM_PAGES );
 	if ( !entry->pagelist ) {
 		DRM(free)( entry, sizeof(*entry), DRM_MEM_SGLISTS );
-		return -ENOMEM;
+		return NULL;
 	}
 
 	memset(entry->pagelist, 0, pages * sizeof(*entry->pagelist));
@@ -109,7 +116,7 @@ int DRM(sg_alloc)( struct inode *inode, struct file *filp,
 		DRM(free)( entry,
 			   sizeof(*entry),
 			   DRM_MEM_SGLISTS );
-		return -ENOMEM;
+		return NULL;
 	}
 	memset( (void *)entry->busaddr, 0, pages * sizeof(*entry->busaddr) );
 
@@ -124,7 +131,7 @@ int DRM(sg_alloc)( struct inode *inode, struct file *filp,
 		DRM(free)( entry,
 			   sizeof(*entry),
 			   DRM_MEM_SGLISTS );
-		return -ENOMEM;
+		return NULL;
 	}
 
 	/* This also forces the mapping of COW pages, so our page list
@@ -144,21 +151,7 @@ int DRM(sg_alloc)( struct inode *inode, struct file *filp,
 		SetPageReserved(entry->pagelist[j]);
 	}
 
-	request.handle = entry->handle;
-
-	if ( copy_to_user( (drm_scatter_gather_t *)arg,
-			   &request,
-			   sizeof(request) ) ) {
-		DRM(sg_cleanup)( entry );
-		return -EFAULT;
-	}
-
-	dev->sg = entry;
-
 #if DEBUG_SCATTER
-	/* Verify that each page points to its virtual address, and vice
-	 * versa.
-	 */
 	{
 	int error = 0;
 
@@ -195,14 +188,83 @@ int DRM(sg_alloc)( struct inode *inode, struct file *filp,
 	}
 #endif
 
-	return 0;
+	return entry;
 
  failed:
-	DRM(sg_cleanup)( entry );
-	return -ENOMEM;
+	DRM(sg_free)( entry );
+	return NULL;
 }
 
-int DRM(sg_free)( struct inode *inode, struct file *filp,
+
+/**********************************************************************/
+/** \name Ioctl's 
+ *
+ * These expose the scatter/gather memory functions to user-space, 
+ * doing the necessary parameter verification and book-keeping to avoid memory
+ * leaks.
+ *
+ * In the current implementation only one scatter/gather memory block can be
+ * allocated per device at a given instance.
+ *
+ * The information about the currently allocated scatter/gather memory block is
+ * stored in drm_device_t::sg.
+ */
+/*@{*/
+
+/** 
+ * Wrapper ioctl around sg_alloc().
+ * 
+ * \param inode device inode.
+ * \param filp file pointer.
+ * \param cmd command.
+ * \param arg user argument, pointing to a drm_scatter_gather structure.
+ * \return zero on success or a negative number on failure.
+ */
+int DRM(sg_alloc_ioctl)( struct inode *inode, struct file *filp,
+		   unsigned int cmd, unsigned long arg )
+{
+	drm_file_t *priv = filp->private_data;
+	drm_device_t *dev = priv->dev;
+	drm_scatter_gather_t request;
+	drm_sg_mem_t *entry;
+
+	DRM_DEBUG( "%s\n", __FUNCTION__ );
+
+	if ( dev->sg )
+		return -EINVAL;
+
+	if ( copy_from_user( &request,
+			     (drm_scatter_gather_t *)arg,
+			     sizeof(request) ) )
+		return -EFAULT;
+
+	entry = DRM(sg_alloc)( request.size  );
+	if ( !entry )
+		return -ENOMEM;
+
+	request.handle = entry->handle;
+
+	if ( copy_to_user( (drm_scatter_gather_t *)arg,
+			   &request,
+			   sizeof(request) ) ) {
+		DRM(sg_free)( entry );
+		return -EFAULT;
+	}
+
+	dev->sg = entry;
+
+	return 0;
+}
+
+/** Wrapper around sg_free().
+ * 
+ * \param inode device inode.
+ * \param filp file pointer.
+ * \param cmd command.
+ * \param arg user argument, pointing to a drm_scatter_gather structure.
+ * \return zero on success or a negative number on failure.
+ */
+int DRM(sg_free_ioctl)( struct inode *inode, struct file *filp,
 		 unsigned int cmd, unsigned long arg )
 {
 	drm_file_t *priv = filp->private_data;
@@ -223,7 +285,25 @@ int DRM(sg_free)( struct inode *inode, struct file *filp,
 
 	DRM_DEBUG( "sg free virtual  = %p\n", entry->virtual );
 
-	DRM(sg_cleanup)( entry );
+	DRM(sg_free)( entry );
 
 	return 0;
 }
+
+/*@}*/
+
+
+/**
+ * Called by takedown() to free the scatter/gather memory resources associated
+ * with a given device, i.e., to free drm_device_t::sg.
+ */
+void DRM(sg_cleanup)(drm_device_t *dev)
+{
+	if ( dev->sg ) {
+		DRM(sg_free)( dev->sg );
+		dev->sg = NULL;
+	}
+}
+
+
+#endif
diff --git a/linux/gamma_drv.c b/linux/gamma_drv.c
index f1b8b205..1313418e 100644
--- a/linux/gamma_drv.c
+++ b/linux/gamma_drv.c
@@ -37,7 +37,7 @@
 #include "gamma_drv.h"
 
 #include "drm_auth.h"
-#include "drm_agpsupport.h"
+#include "drm_agp_tmp.h"
 #include "drm_bufs.h"
 #include "gamma_context.h"	/* NOTE! */
 #include "drm_dma.h"
diff --git a/linux/i810_drv.c b/linux/i810_drv.c
index 0bc79386..2b816fbf 100644
--- a/linux/i810_drv.c
+++ b/linux/i810_drv.c
@@ -37,7 +37,7 @@
 #include "i810_drm.h"
 #include "i810_drv.h"
 
-#include "drm_agpsupport.h"
+#include "drm_agp_tmp.h"
 #include "drm_auth.h"
 #include "drm_bufs.h"
 #include "drm_context.h"
diff --git a/linux/i830_drv.c b/linux/i830_drv.c
index 0735c94d..496c41ee 100644
--- a/linux/i830_drv.c
+++ b/linux/i830_drv.c
@@ -39,7 +39,7 @@
 #include "i830_drm.h"
 #include "i830_drv.h"
 
-#include "drm_agpsupport.h"
+#include "drm_agp_tmp.h"
 #include "drm_auth.h"
 #include "drm_bufs.h"
 #include "drm_context.h"
diff --git a/linux/mga_drv.c b/linux/mga_drv.c
index f0d4935d..f438660c 100644
--- a/linux/mga_drv.c
+++ b/linux/mga_drv.c
@@ -35,7 +35,7 @@
 #include "drm.h"
 #include "mga_drm.h"
 #include "mga_drv.h"
-#include "drm_agpsupport.h"
+#include "drm_agp_tmp.h"
 #include "drm_auth.h"
 #include "drm_bufs.h"
 #include "drm_context.h"
diff --git a/linux/r128_drv.c b/linux/r128_drv.c
index e2e42690..474c1418 100644
--- a/linux/r128_drv.c
+++ b/linux/r128_drv.c
@@ -37,7 +37,7 @@
 #include "r128_drv.h"
 #include "ati_pcigart.h"
 
-#include "drm_agpsupport.h"
+#include "drm_agp_tmp.h"
 #include "drm_auth.h"
 #include "drm_bufs.h"
 #include "drm_context.h"
@@ -52,4 +52,4 @@
 #include "drm_proc.h"
 #include "drm_vm.h"
 #include "drm_stub.h"
-#include "drm_scatter.h"
+#include "drm_sg_tmp.h"
diff --git a/linux/radeon_drv.c b/linux/radeon_drv.c
index 6152b8a5..1473e2ee 100644
--- a/linux/radeon_drv.c
+++ b/linux/radeon_drv.c
@@ -38,7 +38,7 @@
 #include "radeon_drv.h"
 #include "ati_pcigart.h"
 
-#include "drm_agpsupport.h"
+#include "drm_agp_tmp.h"
 #include "drm_auth.h"
 #include "drm_bufs.h"
 #include "drm_context.h"
@@ -53,4 +53,4 @@
 #include "drm_proc.h"
 #include "drm_vm.h"
 #include "drm_stub.h"
-#include "drm_scatter.h"
+#include "drm_sg_tmp.h"
diff --git a/linux/sis_drv.c b/linux/sis_drv.c
index 3dd075d3..64d0754f 100644
--- a/linux/sis_drv.c
+++ b/linux/sis_drv.c
@@ -32,7 +32,7 @@
 #include "sis_drv.h"
 
 #include "drm_auth.h"
-#include "drm_agpsupport.h"
+#include "drm_agp_tmp.h"
 #include "drm_bufs.h"
 #include "drm_context.h"
 #include "drm_dma.h"