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.

1 files changed, 309 insertions, 0 deletions

diff --git a/linux/drm_sg_tmp.h b/linux/drm_sg_tmp.h
new file mode 100644
index 00000000..95cb1fc7
--- /dev/null
+++ b/linux/drm_sg_tmp.h
@@ -0,0 +1,309 @@
+/**
+ * \file drm_sg_tmp.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.
+ */
+
+
+#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
+
+
+/** 
+ * 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;
+
+	for ( i = 0 ; i < entry->pages ; i++ ) {
+		page = entry->pagelist[i];
+		if ( page )
+			ClearPageReserved( page );
+	}
+
+	vfree( entry->virtual );
+
+	DRM(free)( entry->busaddr,
+		   entry->pages * sizeof(*entry->busaddr),
+		   DRM_MEM_PAGES );
+	DRM(free)( entry->pagelist,
+		   entry->pages * sizeof(*entry->pagelist),
+		   DRM_MEM_PAGES );
+	DRM(free)( entry,
+		   sizeof(*entry),
+		   DRM_MEM_SGLISTS );
+}
+
+/** 
+ * 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_sg_mem_t *entry;
+	unsigned long pages, i, j;
+
+	DRM_DEBUG( "%s\n", __FUNCTION__ );
+
+	entry = DRM(alloc)( sizeof(*entry), DRM_MEM_SGLISTS );
+	if ( !entry )
+		return NULL;
+
+   	memset( entry, 0, sizeof(*entry) );
+
+	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 NULL;
+	}
+
+	memset(entry->pagelist, 0, pages * sizeof(*entry->pagelist));
+
+	entry->busaddr = DRM(alloc)( pages * sizeof(*entry->busaddr),
+				     DRM_MEM_PAGES );
+	if ( !entry->busaddr ) {
+		DRM(free)( entry->pagelist,
+			   entry->pages * sizeof(*entry->pagelist),
+			   DRM_MEM_PAGES );
+		DRM(free)( entry,
+			   sizeof(*entry),
+			   DRM_MEM_SGLISTS );
+		return NULL;
+	}
+	memset( (void *)entry->busaddr, 0, pages * sizeof(*entry->busaddr) );
+
+	entry->virtual = vmalloc_32( pages << PAGE_SHIFT );
+	if ( !entry->virtual ) {
+		DRM(free)( entry->busaddr,
+			   entry->pages * sizeof(*entry->busaddr),
+			   DRM_MEM_PAGES );
+		DRM(free)( entry->pagelist,
+			   entry->pages * sizeof(*entry->pagelist),
+			   DRM_MEM_PAGES );
+		DRM(free)( entry,
+			   sizeof(*entry),
+			   DRM_MEM_SGLISTS );
+		return NULL;
+	}
+
+	/* This also forces the mapping of COW pages, so our page list
+	 * will be valid.  Please don't remove it...
+	 */
+	memset( entry->virtual, 0, pages << PAGE_SHIFT );
+
+	entry->handle = (unsigned long)entry->virtual;
+
+	DRM_DEBUG( "sg alloc handle  = %08lx\n", entry->handle );
+	DRM_DEBUG( "sg alloc virtual = %p\n", entry->virtual );
+
+	for ( i = entry->handle, j = 0 ; j < pages ; i += PAGE_SIZE, j++ ) {
+		entry->pagelist[j] = vmalloc_to_page((void *)i);
+		if (!entry->pagelist[j])
+			goto failed;
+		SetPageReserved(entry->pagelist[j]);
+	}
+
+#if DEBUG_SCATTER
+	{
+	int error = 0;
+
+	for ( i = 0 ; i < pages ; i++ ) {
+		unsigned long *tmp;
+
+		tmp = page_address( entry->pagelist[i] );
+		for ( j = 0 ;
+		      j < PAGE_SIZE / sizeof(unsigned long) ;
+		      j++, tmp++ ) {
+			*tmp = 0xcafebabe;
+		}
+		tmp = (unsigned long *)((u8 *)entry->virtual +
+					(PAGE_SIZE * i));
+		for( j = 0 ;
+		     j < PAGE_SIZE / sizeof(unsigned long) ;
+		     j++, tmp++ ) {
+			if ( *tmp != 0xcafebabe && error == 0 ) {
+				error = 1;
+				DRM_ERROR( "Scatter allocation error, "
+					   "pagelist does not match "
+					   "virtual mapping\n" );
+			}
+		}
+		tmp = page_address( entry->pagelist[i] );
+		for(j = 0 ;
+		    j < PAGE_SIZE / sizeof(unsigned long) ;
+		    j++, tmp++) {
+			*tmp = 0;
+		}
+	}
+	if (error == 0)
+		DRM_ERROR( "Scatter allocation matches pagelist\n" );
+	}
+#endif
+
+	return entry;
+
+ failed:
+	DRM(sg_free)( entry );
+	return NULL;
+}
+
+
+/**********************************************************************/
+/** \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;
+	drm_device_t *dev = priv->dev;
+	drm_scatter_gather_t request;
+	drm_sg_mem_t *entry;
+
+	if ( copy_from_user( &request,
+			     (drm_scatter_gather_t *)arg,
+			     sizeof(request) ) )
+		return -EFAULT;
+
+	entry = dev->sg;
+	dev->sg = NULL;
+
+	if ( !entry || entry->handle != request.handle )
+		return -EINVAL;
+
+	DRM_DEBUG( "sg free virtual  = %p\n", entry->virtual );
+
+	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