Update to DRI CVS tree

drivers/char/drm/ati_pcigart.h

@@ -30,14 +30,20 @@
 #define __NO_VERSION__
 #include "drmP.h"
 
-#if PAGE_SIZE == 8192
+#if PAGE_SIZE == 65536
+# define ATI_PCIGART_TABLE_ORDER	0
+# define ATI_PCIGART_TABLE_PAGES	(1 << 0)
+#elif PAGE_SIZE == 16384
+# define ATI_PCIGART_TABLE_ORDER	1
+# define ATI_PCIGART_TABLE_PAGES	(1 << 1)
+#elif PAGE_SIZE == 8192
 # define ATI_PCIGART_TABLE_ORDER 	2
 # define ATI_PCIGART_TABLE_PAGES 	(1 << 2)
 #elif PAGE_SIZE == 4096
 # define ATI_PCIGART_TABLE_ORDER 	3
 # define ATI_PCIGART_TABLE_PAGES 	(1 << 3)
 #else
-# error - PAGE_SIZE not 8K or 4K
+# error - PAGE_SIZE not 64K, 16K, 8K or 4K
 #endif
 
 # define ATI_MAX_PCIGART_PAGES		8192	/* 32 MB aperture, 4K pages */

drivers/char/drm/drm.h

@@ -345,6 +345,19 @@ typedef struct drm_irq_busid {
 	int funcnum;
 } drm_irq_busid_t;
 
+typedef enum {
+    _DRM_VBLANK_ABSOLUTE = 0x0,	/* Wait for specific vblank sequence number */
+    _DRM_VBLANK_RELATIVE = 0x1	/* Wait for given number of vblanks */
+} drm_vblank_seq_type_t;
+
+typedef struct drm_radeon_vbl_wait {
+	drm_vblank_seq_type_t type;
+	unsigned int sequence;
+	long tval_sec;
+	long tval_usec;
+} drm_wait_vblank_t;
+
+
 typedef struct drm_agp_mode {
 	unsigned long mode;
 } drm_agp_mode_t;
@@ -439,6 +452,8 @@ typedef struct drm_scatter_gather {
 #define DRM_IOCTL_SG_ALLOC		DRM_IOW( 0x38, drm_scatter_gather_t)
 #define DRM_IOCTL_SG_FREE		DRM_IOW( 0x39, drm_scatter_gather_t)
 
+#define DRM_IOCTL_WAIT_VBLANK		DRM_IOWR(0x3a, drm_wait_vblank_t)
+
 /* Device specfic ioctls should only be in their respective headers
  * The device specific ioctl range is 0x40 to 0x79.                  */
 #define DRM_COMMAND_BASE                0x40

drivers/char/drm/drmP.h

@@ -576,6 +576,10 @@ typedef struct drm_device {
 	int		  last_context;	/* Last current context		   */
 	unsigned long	  last_switch;	/* jiffies at last context switch  */
 	struct work_struct		  work;
+#if __HAVE_VBL_IRQ
+   	wait_queue_head_t vbl_queue;
+   	atomic_t          vbl_received;
+#endif
 	cycles_t	  ctx_start;
 	cycles_t	  lck_start;
 #if __HAVE_DMA_HISTOGRAM
@@ -808,6 +812,14 @@ extern int           DRM(irq_install)( drm_device_t *dev, int irq );
 extern int           DRM(irq_uninstall)( drm_device_t *dev );
 extern void          DRM(dma_service)( int irq, void *device,
 				       struct pt_regs *regs );
+extern void          DRM(driver_irq_preinstall)( drm_device_t *dev );
+extern void          DRM(driver_irq_postinstall)( drm_device_t *dev );
+extern void          DRM(driver_irq_uninstall)( drm_device_t *dev );
+#if __HAVE_VBL_IRQ
+extern int           DRM(wait_vblank)(struct inode *inode, struct file *filp,
+				      unsigned int cmd, unsigned long arg);
+extern int           DRM(vblank_wait)(drm_device_t *dev, unsigned int *vbl_seq);
+#endif
 #if __HAVE_DMA_IRQ_BH
 extern void          DRM(dma_immediate_bh)( void *dev );
 #endif

drivers/char/drm/drm_dma.h

@@ -535,8 +535,12 @@ int DRM(irq_install)( drm_device_t *dev, int irq )
 	INIT_WORK(&dev->work, DRM(dma_immediate_bh), dev);
 #endif
 
+#if __HAVE_VBL_IRQ
+	init_waitqueue_head(&dev->vbl_queue);
+#endif
+
 				/* Before installing handler */
-	DRIVER_PREINSTALL();
+	DRM(driver_irq_preinstall)(dev);
 
 				/* Install handler */
 	ret = request_irq( dev->irq, DRM(dma_service),
@@ -549,7 +553,7 @@ int DRM(irq_install)( drm_device_t *dev, int irq )
 	}
 
 				/* After installing handler */
-	DRIVER_POSTINSTALL();
+	DRM(driver_irq_postinstall)(dev);
 
 	return 0;
 }
@@ -568,7 +572,7 @@ int DRM(irq_uninstall)( drm_device_t *dev )
 
 	DRM_DEBUG( "%s: irq=%d\n", __FUNCTION__, irq );
 
-	DRIVER_UNINSTALL();
+	DRM(driver_irq_uninstall)( dev );
 
 	free_irq( irq, dev );
 
@@ -595,6 +599,40 @@ int DRM(control)( struct inode *inode, struct file *filp,
 	}
 }
 
+#if __HAVE_VBL_IRQ
+
+int DRM(wait_vblank)( DRM_IOCTL_ARGS )
+{
+	drm_file_t *priv = filp->private_data;
+	drm_device_t *dev = priv->dev;
+	drm_wait_vblank_t vblwait;
+	struct timeval now;
+	int ret;
+
+	if (!dev->irq)
+		return -EINVAL;
+
+	DRM_COPY_FROM_USER_IOCTL( vblwait, (drm_wait_vblank_t *)data,
+				  sizeof(vblwait) );
+
+	if ( vblwait.type == _DRM_VBLANK_RELATIVE ) {
+		vblwait.sequence += atomic_read( &dev->vbl_received );
+	}
+
+	ret = DRM(vblank_wait)( dev, &vblwait.sequence );
+
+	do_gettimeofday( &now );
+	vblwait.tval_sec = now.tv_sec;
+	vblwait.tval_usec = now.tv_usec;
+
+	DRM_COPY_TO_USER_IOCTL( (drm_wait_vblank_t *)data, vblwait,
+				sizeof(vblwait) );
+
+	return ret;
+}
+
+#endif	/* __HAVE_VBL_IRQ */
+
 #else
 
 int DRM(control)( struct inode *inode, struct file *filp,

drivers/char/drm/drm_drv.h

@@ -222,6 +222,10 @@ static drm_ioctl_desc_t		  DRM(ioctls)[] = {
 	[DRM_IOCTL_NR(DRM_IOCTL_SG_FREE)]       = { DRM(sg_free),     1, 1 },
 #endif
 
+#if __HAVE_VBL_IRQ
+	[DRM_IOCTL_NR(DRM_IOCTL_WAIT_VBLANK)]   = { DRM(wait_vblank), 0, 0 },
+#endif
+
 	DRIVER_IOCTLS
 };
 

drivers/char/drm/drm_os_linux.h

@@ -57,3 +57,34 @@ do { 										 \
  		}							 \
  	}								 \
 } while (0)
+
+#define DRM_HZ HZ
+
+#define DRM_WAIT_ON( ret, queue, timeout, condition )	\
+do {							\
+	DECLARE_WAITQUEUE(entry, current);		\
+	unsigned long end = jiffies + (timeout);	\
+	add_wait_queue(&(queue), &entry);		\
+							\
+	for (;;) {					\
+		current->state = TASK_INTERRUPTIBLE;	\
+		if (condition) 				\
+			break;				\
+		if((signed)(end - jiffies) <= 0) {	\
+			ret = -EBUSY;			\
+			break;				\
+		}					\
+		schedule_timeout(max(HZ/100,1));	\
+		if (signal_pending(current)) {		\
+			ret = -EINTR;			\
+			break;				\
+		}					\
+	}						\
+	current->state = TASK_RUNNING;			\
+	remove_wait_queue(&(queue), &entry);		\
+} while (0)
+
+
+#define DRM_WAKEUP( queue ) wake_up_interruptible( queue )
+#define DRM_INIT_WAITQUEUE( queue ) init_waitqueue_head( queue )
+ 

drivers/char/drm/radeon.h

@@ -100,6 +100,13 @@
  [DRM_IOCTL_NR(DRM_IOCTL_RADEON_IRQ_EMIT)]   = { radeon_irq_emit, 1, 0 }, \
  [DRM_IOCTL_NR(DRM_IOCTL_RADEON_IRQ_WAIT)]   = { radeon_irq_wait, 1, 0 },
 
+
+#define USE_IRQS 1
+#if USE_IRQS
+#define __HAVE_DMA_IRQ		1
+#define __HAVE_VBL_IRQ		1
+#define __HAVE_SHARED_IRQ       1
+
 /* When a client dies:
  *    - Check for and clean up flipped page state
  *    - Free any alloced agp memory.
@@ -128,56 +135,14 @@
 	}								\
 } while (0)
 
-/* DMA customization:
- */
-#define __HAVE_DMA		1
-
-
-#define __HAVE_DMA_IRQ		1
-#define __HAVE_DMA_IRQ_BH	1 
-#define __HAVE_SHARED_IRQ       1
-
-#define DRIVER_PREINSTALL() do {				\
-	drm_radeon_private_t *dev_priv =			\
-		(drm_radeon_private_t *)dev->dev_private;	\
-	u32 tmp;						\
-								\
-	/* Clear bit if it's already high: */			\
-   	tmp = RADEON_READ( RADEON_GEN_INT_STATUS );		\
-   	tmp = tmp & RADEON_SW_INT_TEST_ACK;			\
-   	RADEON_WRITE( RADEON_GEN_INT_STATUS, tmp );		\
-								\
- 	/* Disable *all* interrupts */				\
-      	RADEON_WRITE( RADEON_GEN_INT_CNTL, 0 );			\
-} while (0)
-
-#ifdef __linux__ 
-#define IWH(x) init_waitqueue_head(x) 
 #else
-#define IWH(x) 
+#define __HAVE_DMA_IRQ 0
 #endif
 
-#define DRIVER_POSTINSTALL() do {				\
-	drm_radeon_private_t *dev_priv =			\
-		(drm_radeon_private_t *)dev->dev_private;	\
-								\
-   	atomic_set(&dev_priv->irq_received, 0);			\
-   	atomic_set(&dev_priv->irq_emitted, 0);			\
-	IWH(&dev_priv->irq_queue);		\
-								\
-	/* Turn on SW_INT only */				\
-   	RADEON_WRITE( RADEON_GEN_INT_CNTL,			\
-		      RADEON_SW_INT_ENABLE );			\
-} while (0)
+/* DMA customization:
+ */
+#define __HAVE_DMA		1
 
-#define DRIVER_UNINSTALL() do {					\
-	drm_radeon_private_t *dev_priv =			\
-		(drm_radeon_private_t *)dev->dev_private;	\
-	if ( dev_priv ) {					\
-		/* Disable *all* interrupts */			\
-		RADEON_WRITE( RADEON_GEN_INT_CNTL, 0 );		\
-	}							\
-} while (0)
 
 /* Buffer customization:
  */

drivers/char/drm/radeon_drm.h

@@ -517,7 +517,7 @@ typedef struct drm_radeon_indirect {
 #define RADEON_PARAM_LAST_FRAME            2
 #define RADEON_PARAM_LAST_DISPATCH         3
 #define RADEON_PARAM_LAST_CLEAR            4
-#define RADEON_PARAM_IRQ_ACTIVE            5
+#define RADEON_PARAM_IRQ_NR                5
 #define RADEON_PARAM_AGP_BASE              6 /* card offset of agp base */
 
 typedef struct drm_radeon_getparam {

drivers/char/drm/radeon_drv.h

@@ -139,9 +139,9 @@ typedef struct drm_radeon_private {
 	struct mem_block *agp_heap;
 	struct mem_block *fb_heap;
 
-   	wait_queue_head_t irq_queue;
-   	atomic_t irq_received;
-   	atomic_t irq_emitted;
+	/* SW interrupt */
+   	wait_queue_head_t swi_queue;
+   	atomic_t swi_emitted;
 
 } drm_radeon_private_t;
 
@@ -187,11 +187,12 @@ extern int radeon_mem_init_heap( DRM_IOCTL_ARGS );
 extern void radeon_mem_takedown( struct mem_block **heap );
 extern void radeon_mem_release( struct mem_block *heap );
 
+				/* radeon_irq.c */
 extern int radeon_irq_emit( DRM_IOCTL_ARGS );
 extern int radeon_irq_wait( DRM_IOCTL_ARGS );
 
 extern int radeon_emit_and_wait_irq(drm_device_t *dev);
-extern int radeon_wait_irq(drm_device_t *dev, int irq_nr);
+extern int radeon_wait_irq(drm_device_t *dev, int swi_nr);
 extern int radeon_emit_irq(drm_device_t *dev);
 
 
@@ -271,11 +272,15 @@ extern int radeon_emit_irq(drm_device_t *dev);
 
 
 #define RADEON_GEN_INT_CNTL		0x0040
+#	define RADEON_CRTC_VBLANK_MASK		(1 << 0)
 #	define RADEON_GUI_IDLE_INT_ENABLE	(1 << 19)
 #	define RADEON_SW_INT_ENABLE		(1 << 25)
 
 #define RADEON_GEN_INT_STATUS		0x0044
+#	define RADEON_CRTC_VBLANK_STAT		(1 << 0)
+#	define RADEON_CRTC_VBLANK_STAT_ACK   	(1 << 0)
 #	define RADEON_GUI_IDLE_INT_TEST_ACK     (1 << 19)
+#	define RADEON_SW_INT_TEST		(1 << 25)
 #	define RADEON_SW_INT_TEST_ACK   	(1 << 25)
 #	define RADEON_SW_INT_FIRE		(1 << 26)
 
@@ -632,6 +637,7 @@ extern int radeon_emit_irq(drm_device_t *dev);
 #define RADEON_LAST_FRAME_REG		RADEON_SCRATCH_REG0
 #define RADEON_LAST_DISPATCH_REG	RADEON_SCRATCH_REG1
 #define RADEON_LAST_CLEAR_REG		RADEON_SCRATCH_REG2
+#define RADEON_LAST_SWI_REG		RADEON_SCRATCH_REG3
 #define RADEON_LAST_DISPATCH		1
 
 #define RADEON_MAX_VB_AGE		0x7fffffff

drivers/char/drm/radeon_irq.c

-/* radeon_mem.c -- Simple agp/fb memory manager for radeon -*- linux-c -*-
+/* radeon_irq.c -- IRQ handling for radeon -*- linux-c -*-
  *
  * Copyright (C) The Weather Channel, Inc.  2002.  All Rights Reserved.
  * 
@@ -27,6 +27,7 @@
  *
  * Authors:
  *    Keith Whitwell <keith@tungstengraphics.com>
+ *    Michel Dänzer <michel@daenzer.net>
  */
 
 #include "radeon.h"
@@ -58,110 +59,117 @@ void DRM(dma_service)( DRM_IRQ_ARGS )
 	drm_device_t *dev = (drm_device_t *) arg;
 	drm_radeon_private_t *dev_priv = 
 	   (drm_radeon_private_t *)dev->dev_private;
-   	u32 temp;
+   	u32 stat;
 
-	/* Need to wait for fifo to drain?
-	 */
-	temp = RADEON_READ(RADEON_GEN_INT_STATUS);  
-	temp = temp & RADEON_SW_INT_TEST_ACK;  
-	if (temp == 0) return;  
-	RADEON_WRITE(RADEON_GEN_INT_STATUS, temp);  
-
-	atomic_inc(&dev_priv->irq_received);
-#ifdef __linux__
-	schedule_work(&dev->work);
-#endif /* __linux__ */
-#ifdef __FreeBSD__
-	taskqueue_enqueue(taskqueue_swi, &dev->task);
-#endif /* __FreeBSD__ */
-}
+	stat = RADEON_READ(RADEON_GEN_INT_STATUS);
+	if (!stat)
+		return;
 
-void DRM(dma_immediate_bh)( DRM_TASKQUEUE_ARGS )
-{
-	drm_device_t *dev = (drm_device_t *) arg;
-	drm_radeon_private_t *dev_priv = 
-	   (drm_radeon_private_t *)dev->dev_private;
+	/* SW interrupt */
+	if (stat & RADEON_SW_INT_TEST) {
+		DRM_WAKEUP( &dev_priv->swi_queue );
+	}
 
-#ifdef __linux__
-	wake_up_interruptible(&dev_priv->irq_queue); 
-#endif /* __linux__ */
-#ifdef __FreeBSD__
-	wakeup( &dev_priv->irq_queue );
+#if __HAVE_VBL_IRQ
+	/* VBLANK interrupt */
+	if (stat & RADEON_CRTC_VBLANK_STAT) {
+		atomic_inc(&dev->vbl_received);
+		DRM_WAKEUP(&dev->vbl_queue);
+	}
 #endif
+
+	/* Acknowledge all the bits in GEN_INT_STATUS -- seem to get
+	 * more than we asked for...
+	 */
+	RADEON_WRITE(RADEON_GEN_INT_STATUS, stat);
 }
 
+static __inline__ void radeon_acknowledge_irqs(drm_radeon_private_t *dev_priv)
+{
+	u32 tmp = RADEON_READ( RADEON_GEN_INT_STATUS );
+	if (tmp)
+		RADEON_WRITE( RADEON_GEN_INT_STATUS, tmp );
+}
 
 int radeon_emit_irq(drm_device_t *dev)
 {
 	drm_radeon_private_t *dev_priv = dev->dev_private;
+	unsigned int ret;
 	RING_LOCALS;
 
-	atomic_inc(&dev_priv->irq_emitted);
+	atomic_inc(&dev_priv->swi_emitted);
+	ret = atomic_read(&dev_priv->swi_emitted);
 
-	BEGIN_RING(2); 
-	OUT_RING( CP_PACKET0( RADEON_GEN_INT_STATUS, 0 ) );
-	OUT_RING( RADEON_SW_INT_FIRE );
+	BEGIN_RING( 4 );
+	OUT_RING_REG( RADEON_LAST_SWI_REG, ret );
+	OUT_RING_REG( RADEON_GEN_INT_STATUS, RADEON_SW_INT_FIRE );
 	ADVANCE_RING(); 
  	COMMIT_RING();
 
-	return atomic_read(&dev_priv->irq_emitted);
+	return ret;
 }
 
 
-int radeon_wait_irq(drm_device_t *dev, int irq_nr)
+int radeon_wait_irq(drm_device_t *dev, int swi_nr)
 {
   	drm_radeon_private_t *dev_priv = 
 	   (drm_radeon_private_t *)dev->dev_private;
-#ifdef __linux__
-	DECLARE_WAITQUEUE(entry, current);
-	unsigned long end = jiffies + HZ*3;
-#endif /* __linux__ */
 	int ret = 0;
 
- 	if (atomic_read(&dev_priv->irq_received) >= irq_nr)  
+ 	if (RADEON_READ( RADEON_LAST_SWI_REG ) >= swi_nr)  
  		return 0; 
 
 	dev_priv->stats.boxes |= RADEON_BOX_WAIT_IDLE;
 
-#ifdef __linux__
-	add_wait_queue(&dev_priv->irq_queue, &entry);
-
-	for (;;) {
-		current->state = TASK_INTERRUPTIBLE;
-	   	if (atomic_read(&dev_priv->irq_received) >= irq_nr) 
-		   break;
-		if((signed)(end - jiffies) <= 0) {
-		   	ret = -EBUSY;	/* Lockup?  Missed irq? */
-			break;
-		}
-	      	schedule_timeout(HZ*3);
-	      	if (signal_pending(current)) {
-		   	ret = -EINTR;
-			break;
-		}
-	}
+	/* This is a hack to work around mysterious freezes on certain
+	 * systems:
+	 */ 
+	radeon_acknowledge_irqs( dev_priv );
 
-	current->state = TASK_RUNNING;
-	remove_wait_queue(&dev_priv->irq_queue, &entry);
-	return ret;
-#endif /* __linux__ */
+	DRM_WAIT_ON( ret, dev_priv->swi_queue, 3 * DRM_HZ, 
+		     RADEON_READ( RADEON_LAST_SWI_REG ) >= swi_nr );
 
-#ifdef __FreeBSD__
-	ret = tsleep( &dev_priv->irq_queue, PZERO | PCATCH, \
-		"rdnirq", 3*hz );
-	if ( (ret == EWOULDBLOCK) || (ret == EINTR) )
-		return DRM_ERR(EBUSY);
 	return ret;
-#endif /* __FreeBSD__ */
 }
 
-
 int radeon_emit_and_wait_irq(drm_device_t *dev)
 {
 	return radeon_wait_irq( dev, radeon_emit_irq(dev) );
 }
 
 
+#if __HAVE_VBL_IRQ
+int DRM(vblank_wait)(drm_device_t *dev, unsigned int *sequence)
+{
+  	drm_radeon_private_t *dev_priv = 
+	   (drm_radeon_private_t *)dev->dev_private;
+	unsigned int cur_vblank;
+	int ret = 0;
+
+	if ( !dev_priv ) {
+		DRM_ERROR( "%s called with no initialization\n", __FUNCTION__ );
+		return DRM_ERR(EINVAL);
+	}
+
+	radeon_acknowledge_irqs( dev_priv );
+
+	dev_priv->stats.boxes |= RADEON_BOX_WAIT_IDLE;
+
+	/* Assume that the user has missed the current sequence number
+	 * by about a day rather than she wants to wait for years
+	 * using vertical blanks... 
+	 */
+	DRM_WAIT_ON( ret, dev->vbl_queue, 3*DRM_HZ, 
+		     ( ( ( cur_vblank = atomic_read(&dev->vbl_received ) )
+			 + ~*sequence + 1 ) <= (1<<23) ) );
+
+	*sequence = cur_vblank;
+
+	return ret;
+}
+#endif
+
+
 /* Needs the lock as it touches the ring.
  */
 int radeon_irq_emit( DRM_IOCTL_ARGS )
@@ -211,3 +219,38 @@ int radeon_irq_wait( DRM_IOCTL_ARGS )
 	return radeon_wait_irq( dev, irqwait.irq_seq );
 }
 
+
+/* drm_dma.h hooks
+*/
+void DRM(driver_irq_preinstall)( drm_device_t *dev ) {
+	drm_radeon_private_t *dev_priv =
+		(drm_radeon_private_t *)dev->dev_private;
+
+ 	/* Disable *all* interrupts */
+      	RADEON_WRITE( RADEON_GEN_INT_CNTL, 0 );
+
+	/* Clear bits if they're already high */
+	radeon_acknowledge_irqs( dev_priv );
+}
+
+void DRM(driver_irq_postinstall)( drm_device_t *dev ) {
+	drm_radeon_private_t *dev_priv =
+		(drm_radeon_private_t *)dev->dev_private;
+
+   	atomic_set(&dev_priv->swi_emitted, 0);
+	DRM_INIT_WAITQUEUE( &dev_priv->swi_queue );
+
+	/* Turn on SW and VBL ints */
+   	RADEON_WRITE( RADEON_GEN_INT_CNTL,
+		      RADEON_CRTC_VBLANK_MASK |	
+		      RADEON_SW_INT_ENABLE );
+}
+
+void DRM(driver_irq_uninstall)( drm_device_t *dev ) {
+	drm_radeon_private_t *dev_priv =
+		(drm_radeon_private_t *)dev->dev_private;
+	if ( dev_priv ) {
+		/* Disable *all* interrupts */
+		RADEON_WRITE( RADEON_GEN_INT_CNTL, 0 );
+	}
+}

drivers/char/drm/radeon_mem.c

@@ -118,7 +118,7 @@ static void free_block( struct mem_block *p )
 		p->size += q->size;
 		p->next = q->next;
 		p->next->prev = p;
-		DRM_FREE(p);
+		DRM_FREE(q);
 	}
 
 	if (p->prev->pid == 0) {

drivers/char/drm/radeon_state.c

@@ -1283,7 +1283,6 @@ int radeon_cp_clear( DRM_IOCTL_ARGS )
 }
 
 
-
 /* Not sure why this isn't set all the time:
  */ 
 static int radeon_do_init_pageflip( drm_device_t *dev )
@@ -2172,8 +2171,8 @@ int radeon_cp_getparam( DRM_IOCTL_ARGS )
 		dev_priv->stats.last_clear_reads++;
 		value = GET_SCRATCH( 2 );
 		break;
-	case RADEON_PARAM_IRQ_ACTIVE:
-		value = dev->irq ? 1 : 0;
+	case RADEON_PARAM_IRQ_NR:
+		value = dev->irq;
 		break;
 	case RADEON_PARAM_AGP_BASE:
 		value = dev_priv->agp_vm_start;