diff --git a/linux-core/Makefile.kernel b/linux-core/Makefile.kernel
index 57c6c50c..73b9a918 100644
--- a/linux-core/Makefile.kernel
+++ b/linux-core/Makefile.kernel
@@ -13,7 +13,7 @@
 L_TARGET        := libdrm.a
 
 L_OBJS		:= init.o memory.o proc.o auth.o context.o drawable.o bufs.o \
-			lists.o lock.o ioctl.o fops.o vm.o dma.o
+			lists.o lock.o ioctl.o fops.o vm.o dma.o ctxbitmap.o
 
 M_OBJS		:= 
 
@@ -25,6 +25,10 @@ ifdef CONFIG_DRM_TDFX
 M_OBJS          += tdfx.o
 endif
 
+ifdef CONFIG_DRM_MGA
+M_OBJS		+= mga.o
+endif
+
 include $(TOPDIR)/Rules.make
 
 gamma.o: gamma_drv.o gamma_dma.o $(L_TARGET)
@@ -32,3 +36,7 @@ gamma.o: gamma_drv.o gamma_dma.o $(L_TARGET)
 
 tdfx.o: tdfx_drv.o tdfx_context.o $(L_TARGET)
 	$(LD) $(LD_RFLAG) -r -o $@ tdfx_drv.o tdfx_context.o -L. -ldrm
+
+mga.o: mga_drv.o mga_context.o mga_dma.o mga_bufs.o $(L_TARGET)
+	$(LD) $(LD_RFLAG) -r -o $@ mga_drv.o mga_context.o mga_bufs.o mga_dma.o -L. -ldrm
+
diff --git a/linux-core/drmP.h b/linux-core/drmP.h
index d67e6e43..01994a36 100644
--- a/linux-core/drmP.h
+++ b/linux-core/drmP.h
@@ -70,24 +70,27 @@
 #define DRM_FLAG_DEBUG	  0x01
 #define DRM_FLAG_NOCTX	  0x02
 
-#define DRM_MEM_DMA	  0
-#define DRM_MEM_SAREA	  1
-#define DRM_MEM_DRIVER	  2
-#define DRM_MEM_MAGIC	  3
-#define DRM_MEM_IOCTLS	  4
-#define DRM_MEM_MAPS	  5
-#define DRM_MEM_VMAS	  6
-#define DRM_MEM_BUFS	  7
-#define DRM_MEM_SEGS	  8
-#define DRM_MEM_PAGES	  9
-#define DRM_MEM_FILES	 10
-#define DRM_MEM_QUEUES	 11
-#define DRM_MEM_CMDS	 12
-#define DRM_MEM_MAPPINGS 13
-#define DRM_MEM_BUFLISTS 14
-#define DRM_MEM_AGPLISTS 15
-#define DRM_MEM_TOTALAGP 16
-#define DRM_MEM_BOUNDAGP 17
+#define DRM_MEM_DMA	   0
+#define DRM_MEM_SAREA	   1
+#define DRM_MEM_DRIVER	   2
+#define DRM_MEM_MAGIC	   3
+#define DRM_MEM_IOCTLS	   4
+#define DRM_MEM_MAPS	   5
+#define DRM_MEM_VMAS	   6
+#define DRM_MEM_BUFS	   7
+#define DRM_MEM_SEGS	   8
+#define DRM_MEM_PAGES	   9
+#define DRM_MEM_FILES	  10
+#define DRM_MEM_QUEUES	  11
+#define DRM_MEM_CMDS	  12
+#define DRM_MEM_MAPPINGS  13
+#define DRM_MEM_BUFLISTS  14
+#define DRM_MEM_AGPLISTS  15
+#define DRM_MEM_TOTALAGP  16
+#define DRM_MEM_BOUNDAGP  17
+#define DRM_MEM_CTXBITMAP 18
+
+#define DRM_MAX_CTXBITMAP (PAGE_SIZE * 4 * 8)
 
 				/* Backward compatibility section */
 				/* _PAGE_WT changed to _PAGE_PWT in 2.2.6 */
@@ -504,6 +507,7 @@ typedef struct drm_device {
 #ifdef DRM_AGP
 	drm_agp_head_t    *agp;
 #endif
+	unsigned long     *ctx_bitmap;
 } drm_device_t;
 
 
@@ -692,6 +696,12 @@ extern int	     drm_flush_unblock(drm_device_t *dev, int context,
 extern int	     drm_flush_block_and_flush(drm_device_t *dev, int context,
 					       drm_lock_flags_t flags);
 
+				/* Context Bitmap support (ctxbitmap.c) */
+extern int	     drm_ctxbitmap_init(drm_device_t *dev);
+extern void	     drm_ctxbitmap_cleanup(drm_device_t *dev);
+extern int	     drm_ctxbitmap_next(drm_device_t *dev);
+extern void	     drm_ctxbitmap_free(drm_device_t *dev, int ctx_handle);
+
 #ifdef DRM_AGP
 				/* AGP/GART support (agpsupport.c) */
 extern drm_agp_head_t *drm_agp_init(void);
diff --git a/linux-core/mga_drv.c b/linux-core/mga_drv.c
index 68083547..37ded285 100644
--- a/linux-core/mga_drv.c
+++ b/linux-core/mga_drv.c
@@ -1,6 +1,5 @@
 /* mga_drv.c -- Matrox g200/g400 driver -*- linux-c -*-
  * Created: Mon Dec 13 01:56:22 1999 by jhartmann@precisioninsight.com
- * Revised: Mon Dec 13 02:26:34 1999 by jhartmann@precisioninsight.com
  * 
  * Copyright 1999 Precision Insight, Inc., Cedar Park, Texas.
  * All Rights Reserved.
@@ -23,7 +22,11 @@
  * 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.
- * 
+ *
+ * Authors: Rickard E. (Rik) Faith <faith@precisioninsight.com>
+ *	    Jeff Hartmann <jhartmann@precisioninsight.com>
+ *
+ * $XFree86$
  *
  */
 
@@ -70,26 +73,36 @@ static drm_ioctl_desc_t	      mga_ioctls[] = {
 	[DRM_IOCTL_NR(DRM_IOCTL_CONTROL)]    = { mga_control,	  1, 1 },
 	[DRM_IOCTL_NR(DRM_IOCTL_AUTH_MAGIC)] = { drm_authmagic,	  1, 1 },
 	[DRM_IOCTL_NR(DRM_IOCTL_ADD_MAP)]    = { drm_addmap,	  1, 1 },
-	[DRM_IOCTL_NR(DRM_IOCTL_ADD_BUFS)]   = { drm_addbufs,	  1, 1 },
-	[DRM_IOCTL_NR(DRM_IOCTL_MARK_BUFS)]  = { drm_markbufs,	  1, 1 },
-	[DRM_IOCTL_NR(DRM_IOCTL_INFO_BUFS)]  = { drm_infobufs,	  1, 0 },
-	[DRM_IOCTL_NR(DRM_IOCTL_MAP_BUFS)]   = { drm_mapbufs,	  1, 0 },
-	[DRM_IOCTL_NR(DRM_IOCTL_FREE_BUFS)]  = { drm_freebufs,	  1, 0 },
-	
-	[DRM_IOCTL_NR(DRM_IOCTL_ADD_CTX)]    = { drm_addctx,	  1, 1 },
-	[DRM_IOCTL_NR(DRM_IOCTL_RM_CTX)]     = { drm_rmctx,	  1, 1 },
-	[DRM_IOCTL_NR(DRM_IOCTL_MOD_CTX)]    = { drm_modctx,	  1, 1 },
-	[DRM_IOCTL_NR(DRM_IOCTL_GET_CTX)]    = { drm_getctx,	  1, 0 },
-	[DRM_IOCTL_NR(DRM_IOCTL_SWITCH_CTX)] = { drm_switchctx,	  1, 1 },
-	[DRM_IOCTL_NR(DRM_IOCTL_NEW_CTX)]    = { drm_newctx,	  1, 1 },
-	[DRM_IOCTL_NR(DRM_IOCTL_RES_CTX)]    = { drm_resctx,	  1, 0 },
+	[DRM_IOCTL_NR(DRM_IOCTL_ADD_BUFS)]   = { mga_addbufs,	  1, 1 },
+	[DRM_IOCTL_NR(DRM_IOCTL_MARK_BUFS)]  = { mga_markbufs,	  1, 1 },
+	[DRM_IOCTL_NR(DRM_IOCTL_INFO_BUFS)]  = { mga_infobufs,	  1, 0 },
+	[DRM_IOCTL_NR(DRM_IOCTL_MAP_BUFS)]   = { mga_mapbufs,	  1, 0 },
+	[DRM_IOCTL_NR(DRM_IOCTL_FREE_BUFS)]  = { mga_freebufs,	  1, 0 },
+
+	[DRM_IOCTL_NR(DRM_IOCTL_ADD_CTX)]    = { mga_addctx,	  1, 1 },
+	[DRM_IOCTL_NR(DRM_IOCTL_RM_CTX)]     = { mga_rmctx,	  1, 1 },
+	[DRM_IOCTL_NR(DRM_IOCTL_MOD_CTX)]    = { mga_modctx,	  1, 1 },
+	[DRM_IOCTL_NR(DRM_IOCTL_GET_CTX)]    = { mga_getctx,	  1, 0 },
+	[DRM_IOCTL_NR(DRM_IOCTL_SWITCH_CTX)] = { mga_switchctx,	  1, 1 },
+	[DRM_IOCTL_NR(DRM_IOCTL_NEW_CTX)]    = { mga_newctx,	  1, 1 },
+	[DRM_IOCTL_NR(DRM_IOCTL_RES_CTX)]    = { mga_resctx,	  1, 0 },
 	[DRM_IOCTL_NR(DRM_IOCTL_ADD_DRAW)]   = { drm_adddraw,	  1, 1 },
 	[DRM_IOCTL_NR(DRM_IOCTL_RM_DRAW)]    = { drm_rmdraw,	  1, 1 },
 	[DRM_IOCTL_NR(DRM_IOCTL_DMA)]	     = { mga_dma,	  1, 0 },
 	[DRM_IOCTL_NR(DRM_IOCTL_LOCK)]	     = { mga_lock,	  1, 0 },
 	[DRM_IOCTL_NR(DRM_IOCTL_UNLOCK)]     = { mga_unlock,	  1, 0 },
 	[DRM_IOCTL_NR(DRM_IOCTL_FINISH)]     = { drm_finish,	  1, 0 },
+
+        [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, 1},
+        [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_unbind,  1, 1},
+        [DRM_IOCTL_NR(DRM_IOCTL_AGP_UNBIND)]	= {drm_agp_bind,    1, 1},
 };
+
 #define MGA_IOCTL_COUNT DRM_ARRAY_SIZE(mga_ioctls)
 
 #ifdef MODULE
@@ -269,6 +282,8 @@ static int mga_takedown(drm_device_t *dev)
 					       - PAGE_SHIFT,
 					       DRM_MEM_SAREA);
 				break;
+			case _DRM_AGP:
+				break;
 			}
 			drm_free(map, sizeof(*map), DRM_MEM_MAPS);
 		}
@@ -319,6 +334,10 @@ int mga_init(void)
 	DRM_DEBUG("\n");
 
 	memset((void *)dev, 0, sizeof(*dev));
+	if((retcode = drm_ctxbitmap_init(dev))) {
+		DRM_ERROR("Cannot allocate memory for context bitmap.\n");
+		return retcode;
+	}
 	dev->count_lock	  = SPIN_LOCK_UNLOCKED;
 	sema_init(&dev->struct_sem, 1);
 	
@@ -328,6 +347,7 @@ int mga_init(void)
 
 	if ((retcode = misc_register(&mga_misc))) {
 		DRM_ERROR("Cannot register \"%s\"\n", MGA_NAME);
+		drm_ctxbitmap_cleanup(dev);
 		return retcode;
 	}
 	dev->device = MKDEV(MISC_MAJOR, mga_misc.minor);
@@ -343,7 +363,9 @@ int mga_init(void)
 		 MGA_PATCHLEVEL,
 		 MGA_DATE,
 		 mga_misc.minor);
-	
+
+	dev->agp    = drm_agp_init();
+
 	return 0;
 }
 
@@ -362,6 +384,7 @@ void mga_cleanup(void)
 		DRM_INFO("Module unloaded\n");
 	}
 	mga_takedown(dev);
+	drm_ctxbitmap_cleanup(dev);
 }
 
 int mga_version(struct inode *inode, struct file *filp, unsigned int cmd,
@@ -484,6 +507,151 @@ int mga_ioctl(struct inode *inode, struct file *filp, unsigned int cmd,
 	return retcode;
 }
 
+int mga_lock(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;
+        DECLARE_WAITQUEUE(entry, current);
+        int               ret   = 0;
+        drm_lock_t        lock;
+#if DRM_DMA_HISTOGRAM
+        cycles_t          start;
+
+        dev->lck_start = start = get_cycles();
+#endif
+
+        copy_from_user_ret(&lock, (drm_lock_t *)arg, sizeof(lock), -EFAULT);
+
+        if (lock.context == DRM_KERNEL_CONTEXT) {
+                DRM_ERROR("Process %d using kernel context %d\n",
+                          current->pid, lock.context);
+                return -EINVAL;
+        }
+
+        DRM_DEBUG("%d (pid %d) requests lock (0x%08x), flags = 0x%08x\n",
+                  lock.context, current->pid, dev->lock.hw_lock->lock,
+                  lock.flags);
+
+#if 0
+				/* dev->queue_count == 0 right now for
+                                   mga.  FIXME? */
+        if (lock.context < 0 || lock.context >= dev->queue_count)
+                return -EINVAL;
+#endif
+        
+        if (!ret) {
+#if 0
+                if (_DRM_LOCKING_CONTEXT(dev->lock.hw_lock->lock)
+                    != lock.context) {
+                        long j = jiffies - dev->lock.lock_time;
+
+                        if (lock.context == mga_res_ctx.handle &&
+				j >= 0 && j < DRM_LOCK_SLICE) {
+                                /* Can't take lock if we just had it and
+                                   there is contention. */
+                                DRM_DEBUG("%d (pid %d) delayed j=%d dev=%d jiffies=%d\n",
+					lock.context, current->pid, j, 
+					dev->lock.lock_time, jiffies);
+                                current->state = TASK_INTERRUPTIBLE;
+				current->policy |= SCHED_YIELD;
+                                schedule_timeout(DRM_LOCK_SLICE-j);
+				DRM_DEBUG("jiffies=%d\n", jiffies);
+                        }
+                }
+#endif
+                add_wait_queue(&dev->lock.lock_queue, &entry);
+                for (;;) {
+                        if (!dev->lock.hw_lock) {
+                                /* Device has been unregistered */
+                                ret = -EINTR;
+                                break;
+                        }
+                        if (drm_lock_take(&dev->lock.hw_lock->lock,
+                                          lock.context)) {
+                                dev->lock.pid       = current->pid;
+                                dev->lock.lock_time = jiffies;
+                                atomic_inc(&dev->total_locks);
+                                break;  /* Got lock */
+                        }
+                        
+                                /* Contention */
+                        atomic_inc(&dev->total_sleeps);
+                        current->state = TASK_INTERRUPTIBLE;
+#if 1
+			current->policy |= SCHED_YIELD;
+#endif
+                        schedule();
+                        if (signal_pending(current)) {
+                                ret = -ERESTARTSYS;
+                                break;
+                        }
+                }
+                current->state = TASK_RUNNING;
+                remove_wait_queue(&dev->lock.lock_queue, &entry);
+        }
+
+#if 0
+	if (!ret && dev->last_context != lock.context &&
+		lock.context != mga_res_ctx.handle &&
+		dev->last_context != mga_res_ctx.handle) {
+		add_wait_queue(&dev->context_wait, &entry);
+	        current->state = TASK_INTERRUPTIBLE;
+                /* PRE: dev->last_context != lock.context */
+	        mga_context_switch(dev, dev->last_context, lock.context);
+		/* POST: we will wait for the context
+                   switch and will dispatch on a later call
+                   when dev->last_context == lock.context
+                   NOTE WE HOLD THE LOCK THROUGHOUT THIS
+                   TIME! */
+		current->policy |= SCHED_YIELD;
+	        schedule();
+	        current->state = TASK_RUNNING;
+	        remove_wait_queue(&dev->context_wait, &entry);
+	        if (signal_pending(current)) {
+	                ret = -EINTR;
+	        } else if (dev->last_context != lock.context) {
+			DRM_ERROR("Context mismatch: %d %d\n",
+                        	dev->last_context, lock.context);
+	        }
+	}
+#endif
+
+        if (!ret) {
+                if (lock.flags & _DRM_LOCK_READY) {
+				/* Wait for space in DMA/FIFO */
+		}
+                if (lock.flags & _DRM_LOCK_QUIESCENT) {
+				/* Make hardware quiescent */
+#if 0
+                        mga_quiescent(dev);
+#endif
+		}
+        }
+
+#if 0
+	DRM_ERROR("pid = %5d, old counter = %5ld\n", 
+		current->pid, current->counter);
+#endif
+	if (lock.context != mga_res_ctx.handle) {
+		current->counter = 5;
+		current->priority = DEF_PRIORITY/4;
+	}
+#if 0
+	while (current->counter > 25)
+		current->counter >>= 1; /* decrease time slice */
+	DRM_ERROR("pid = %5d, new counter = %5ld\n",
+		 current->pid, current->counter);
+#endif
+        DRM_DEBUG("%d %s\n", lock.context, ret ? "interrupted" : "has lock");
+
+#if DRM_DMA_HISTOGRAM
+        atomic_inc(&dev->histo.lacq[drm_histogram_slot(get_cycles() - start)]);
+#endif
+        
+        return ret;
+}
+
 
 int mga_unlock(struct inode *inode, struct file *filp, unsigned int cmd,
 		 unsigned long arg)
diff --git a/linux/Makefile.kernel b/linux/Makefile.kernel
index 57c6c50c..73b9a918 100644
--- a/linux/Makefile.kernel
+++ b/linux/Makefile.kernel
@@ -13,7 +13,7 @@
 L_TARGET        := libdrm.a
 
 L_OBJS		:= init.o memory.o proc.o auth.o context.o drawable.o bufs.o \
-			lists.o lock.o ioctl.o fops.o vm.o dma.o
+			lists.o lock.o ioctl.o fops.o vm.o dma.o ctxbitmap.o
 
 M_OBJS		:= 
 
@@ -25,6 +25,10 @@ ifdef CONFIG_DRM_TDFX
 M_OBJS          += tdfx.o
 endif
 
+ifdef CONFIG_DRM_MGA
+M_OBJS		+= mga.o
+endif
+
 include $(TOPDIR)/Rules.make
 
 gamma.o: gamma_drv.o gamma_dma.o $(L_TARGET)
@@ -32,3 +36,7 @@ gamma.o: gamma_drv.o gamma_dma.o $(L_TARGET)
 
 tdfx.o: tdfx_drv.o tdfx_context.o $(L_TARGET)
 	$(LD) $(LD_RFLAG) -r -o $@ tdfx_drv.o tdfx_context.o -L. -ldrm
+
+mga.o: mga_drv.o mga_context.o mga_dma.o mga_bufs.o $(L_TARGET)
+	$(LD) $(LD_RFLAG) -r -o $@ mga_drv.o mga_context.o mga_bufs.o mga_dma.o -L. -ldrm
+
diff --git a/linux/Makefile.linux b/linux/Makefile.linux
index 62c05f92..0ca6748d 100644
--- a/linux/Makefile.linux
+++ b/linux/Makefile.linux
@@ -56,12 +56,12 @@ MODVERSIONS := $(shell \
 
 # **** End of SMP/MODVERSIONS detection
 
-MODS=           gamma.o tdfx.o r128.o
+MODS=           gamma.o tdfx.o mga.o
 LIBS=           libdrm.a
 PROGS=		drmstat
 
 DRMOBJS=	init.o memory.o proc.o auth.o context.o drawable.o bufs.o \
-		lists.o lock.o ioctl.o fops.o vm.o dma.o
+		lists.o lock.o ioctl.o fops.o vm.o dma.o ctxbitmap.c
 DRMHEADERS=	drm.h drmP.h
 
 GAMMAOBJS=      gamma_drv.o gamma_dma.o
@@ -70,8 +70,8 @@ GAMMAHEADERS=   gamma_drv.h $(DRMHEADERS)
 TDFXOBJS=       tdfx_drv.o tdfx_context.o
 TDFXHEADERS=    tdfx_drv.h $(DRMHEADERS)
 
-R128OBJS=       r128_drv.o r128_context.o
-R128HEADERS=    r128_drv.h $(DRMHEADERS)
+MGAOBJS=	mga_drv.o mga_context.o mga_dma.o mga_bufs.o
+MGAHEADERS=	mga_drv.h $(DRMHEADERS)
 
 PROGOBJS=       drmstat.po xf86drm.po xf86drmHash.po xf86drmRandom.po sigio.po
 PROGHEADERS=    xf86drm.h $(DRMHEADERS)
@@ -111,7 +111,7 @@ gamma.o: $(GAMMAOBJS) $(LIBS)
 tdfx.o: $(TDFXOBJS) $(LIBS)
 	$(LD) -r $^ -o $@
 
-r128.o: $(R128OBJS) $(LIBS)
+mga.o: $(MGAOBJS) $(LIBS)
 	$(LD) -r $^ -o $@
 
 drmstat: $(PROGOBJS)
@@ -135,7 +135,7 @@ ChangeLog:
 $(DRMOBJS): $(DRMHEADERS)
 $(GAMMAOBJS): $(GAMMAHEADERS)
 $(TDFXOBJS): $(TDFXHEADERS)
-$(R128OBJS): $(R128HEADERS)
+$(MGAOBJS): $(MGAHEADERS)
 $(PROGOBJS): $(PROGHEADERS)
 
 clean:
diff --git a/linux/ctxbitmap.c b/linux/ctxbitmap.c
new file mode 100644
index 00000000..c9b7da0e
--- /dev/null
+++ b/linux/ctxbitmap.c
@@ -0,0 +1,80 @@
+/* ctxbitmap.c -- Context bitmap management -*- linux-c -*-
+ * Created: Thu Jan 6 03:56:42 2000 by jhartmann@precisioninsight.com
+ * 
+ * Copyright 1999 Precision Insight, Inc., Cedar Park, Texas.
+ * 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.
+ *
+ * Author: Jeff Hartmann <jhartmann@precisioninsight.com>
+ *
+ * $XFree86$
+ *
+ */
+
+#include "drmP.h"
+
+void drm_ctxbitmap_free(drm_device_t *dev, int ctx_handle)
+{
+	if (ctx_handle < 0) goto failed;
+
+	if (ctx_handle < DRM_MAX_CTXBITMAP) {
+		clear_bit(ctx_handle, dev->ctx_bitmap);
+		return;
+	}
+failed:
+       	DRM_DEBUG("Attempt to free invalid context handle: %d\n",
+		  ctx_handle);
+       	return;
+}
+
+int drm_ctxbitmap_next(drm_device_t *dev)
+{
+	int bit;
+
+	bit = find_first_zero_bit(dev->ctx_bitmap, DRM_MAX_CTXBITMAP);
+	if (bit < DRM_MAX_CTXBITMAP) {
+		set_bit(bit, dev->ctx_bitmap);
+		return bit;
+	}
+	return -1;
+}
+
+int drm_ctxbitmap_init(drm_device_t *dev)
+{
+	dev->ctx_bitmap = (unsigned long *) drm_alloc(PAGE_SIZE * 4, 
+						      DRM_MEM_CTXBITMAP);
+	if(dev->ctx_bitmap == NULL) {
+		return -ENOMEM;
+	}
+	memset((void *) dev->ctx_bitmap, 0, PAGE_SIZE * 4);
+	for(i = 0; i < DRM_RESERVED_CONTEXTS; i++) {
+		drm_ctxbitmap_next(dev);
+	}
+
+	return 0;
+}
+
+void drm_ctxbitmap_cleanup(drm_device_t *dev)
+{
+	drm_free((void *)dev->ctx_bitmap, PAGE_SIZE * 4,
+		 DRM_MEM_CTXBITMAP);
+}
+
diff --git a/linux/drmP.h b/linux/drmP.h
index d67e6e43..01994a36 100644
--- a/linux/drmP.h
+++ b/linux/drmP.h
@@ -70,24 +70,27 @@
 #define DRM_FLAG_DEBUG	  0x01
 #define DRM_FLAG_NOCTX	  0x02
 
-#define DRM_MEM_DMA	  0
-#define DRM_MEM_SAREA	  1
-#define DRM_MEM_DRIVER	  2
-#define DRM_MEM_MAGIC	  3
-#define DRM_MEM_IOCTLS	  4
-#define DRM_MEM_MAPS	  5
-#define DRM_MEM_VMAS	  6
-#define DRM_MEM_BUFS	  7
-#define DRM_MEM_SEGS	  8
-#define DRM_MEM_PAGES	  9
-#define DRM_MEM_FILES	 10
-#define DRM_MEM_QUEUES	 11
-#define DRM_MEM_CMDS	 12
-#define DRM_MEM_MAPPINGS 13
-#define DRM_MEM_BUFLISTS 14
-#define DRM_MEM_AGPLISTS 15
-#define DRM_MEM_TOTALAGP 16
-#define DRM_MEM_BOUNDAGP 17
+#define DRM_MEM_DMA	   0
+#define DRM_MEM_SAREA	   1
+#define DRM_MEM_DRIVER	   2
+#define DRM_MEM_MAGIC	   3
+#define DRM_MEM_IOCTLS	   4
+#define DRM_MEM_MAPS	   5
+#define DRM_MEM_VMAS	   6
+#define DRM_MEM_BUFS	   7
+#define DRM_MEM_SEGS	   8
+#define DRM_MEM_PAGES	   9
+#define DRM_MEM_FILES	  10
+#define DRM_MEM_QUEUES	  11
+#define DRM_MEM_CMDS	  12
+#define DRM_MEM_MAPPINGS  13
+#define DRM_MEM_BUFLISTS  14
+#define DRM_MEM_AGPLISTS  15
+#define DRM_MEM_TOTALAGP  16
+#define DRM_MEM_BOUNDAGP  17
+#define DRM_MEM_CTXBITMAP 18
+
+#define DRM_MAX_CTXBITMAP (PAGE_SIZE * 4 * 8)
 
 				/* Backward compatibility section */
 				/* _PAGE_WT changed to _PAGE_PWT in 2.2.6 */
@@ -504,6 +507,7 @@ typedef struct drm_device {
 #ifdef DRM_AGP
 	drm_agp_head_t    *agp;
 #endif
+	unsigned long     *ctx_bitmap;
 } drm_device_t;
 
 
@@ -692,6 +696,12 @@ extern int	     drm_flush_unblock(drm_device_t *dev, int context,
 extern int	     drm_flush_block_and_flush(drm_device_t *dev, int context,
 					       drm_lock_flags_t flags);
 
+				/* Context Bitmap support (ctxbitmap.c) */
+extern int	     drm_ctxbitmap_init(drm_device_t *dev);
+extern void	     drm_ctxbitmap_cleanup(drm_device_t *dev);
+extern int	     drm_ctxbitmap_next(drm_device_t *dev);
+extern void	     drm_ctxbitmap_free(drm_device_t *dev, int ctx_handle);
+
 #ifdef DRM_AGP
 				/* AGP/GART support (agpsupport.c) */
 extern drm_agp_head_t *drm_agp_init(void);
diff --git a/linux/memory.c b/linux/memory.c
index 1c9a4363..b7579156 100644
--- a/linux/memory.c
+++ b/linux/memory.c
@@ -63,6 +63,7 @@ static drm_mem_stats_t	  drm_mem_stats[]   = {
 	[DRM_MEM_AGPLISTS]  = { "agplist"  },
 	[DRM_MEM_TOTALAGP]  = { "totalagp" },
 	[DRM_MEM_BOUNDAGP]  = { "boundagp" },
+	[DRM_MEM_CTXBITMAP] = { "ctxbitmap"},
 	{ NULL, 0, }		/* Last entry must be null */
 };
 
diff --git a/linux/mga_bufs.c b/linux/mga_bufs.c
new file mode 100644
index 00000000..0e9e22f8
--- /dev/null
+++ b/linux/mga_bufs.c
@@ -0,0 +1,427 @@
+/* mga_bufs.c -- IOCTLs to manage buffers -*- linux-c -*-
+ * Created: Thu Jan 6 01:47:26 2000 by jhartmann@precisioninsight.com
+ *
+ * Copyright 1999 Precision Insight, Inc., Cedar Park, Texas.
+ * 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.
+ * 
+ * Authors: Rickard E. (Rik) Faith <faith@precisioninsight.com>
+ *	    Jeff Hartmann <jhartmann@precisioninsight.com>
+ * 
+ * $XFree86$
+ *
+ */
+
+#define __NO_VERSION__
+#include "drmP.h"
+#include "linux/un.h"
+
+int mga_addbufs(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_device_dma_t *dma	 = dev->dma;
+	drm_buf_desc_t	 request;
+	int		 count;
+	int		 order;
+	int		 size;
+	int		 total;
+	int		 page_order;
+	drm_buf_entry_t	 *entry;
+	unsigned long	 page;
+	drm_buf_t	 *buf;
+	int		 alignment;
+	unsigned long	 offset;
+	int		 i;
+	int		 byte_count;
+	int		 page_count;
+
+	if (!dma) return -EINVAL;
+
+	copy_from_user_ret(&request,
+			   (drm_buf_desc_t *)arg,
+			   sizeof(request),
+			   -EFAULT);
+
+	count	   = request.count;
+	order	   = drm_order(request.size);
+	size	   = 1 << order;
+	
+	DRM_DEBUG("count = %d, size = %d (%d), order = %d, queue_count = %d\n",
+		  request.count, request.size, size, order, dev->queue_count);
+
+	if (order < DRM_MIN_ORDER || order > DRM_MAX_ORDER) return -EINVAL;
+	if (dev->queue_count) return -EBUSY; /* Not while in use */
+
+	alignment  = (request.flags & DRM_PAGE_ALIGN) ? PAGE_ALIGN(size) :size;
+	page_order = order - PAGE_SHIFT > 0 ? order - PAGE_SHIFT : 0;
+	total	   = PAGE_SIZE << page_order;
+
+	spin_lock(&dev->count_lock);
+	if (dev->buf_use) {
+		spin_unlock(&dev->count_lock);
+		return -EBUSY;
+	}
+	atomic_inc(&dev->buf_alloc);
+	spin_unlock(&dev->count_lock);
+	
+	down(&dev->struct_sem);
+	entry = &dma->bufs[order];
+	if (entry->buf_count) {
+		up(&dev->struct_sem);
+		atomic_dec(&dev->buf_alloc);
+		return -ENOMEM;	/* May only call once for each order */
+	}
+	
+	entry->buflist = drm_alloc(count * sizeof(*entry->buflist),
+				   DRM_MEM_BUFS);
+	if (!entry->buflist) {
+		up(&dev->struct_sem);
+		atomic_dec(&dev->buf_alloc);
+		return -ENOMEM;
+	}
+	memset(entry->buflist, 0, count * sizeof(*entry->buflist));
+
+	entry->seglist = drm_alloc(count * sizeof(*entry->seglist),
+				   DRM_MEM_SEGS);
+	if (!entry->seglist) {
+		drm_free(entry->buflist,
+			 count * sizeof(*entry->buflist),
+			 DRM_MEM_BUFS);
+		up(&dev->struct_sem);
+		atomic_dec(&dev->buf_alloc);
+		return -ENOMEM;
+	}
+	memset(entry->seglist, 0, count * sizeof(*entry->seglist));
+
+	dma->pagelist = drm_realloc(dma->pagelist,
+				    dma->page_count * sizeof(*dma->pagelist),
+				    (dma->page_count + (count << page_order))
+				    * sizeof(*dma->pagelist),
+				    DRM_MEM_PAGES);
+	DRM_DEBUG("pagelist: %d entries\n",
+		  dma->page_count + (count << page_order));
+
+
+	entry->buf_size	  = size;
+	entry->page_order = page_order;
+	byte_count	  = 0;
+	page_count	  = 0;
+	while (entry->buf_count < count) {
+		if (!(page = drm_alloc_pages(page_order, DRM_MEM_DMA))) break;
+		entry->seglist[entry->seg_count++] = page;
+		for (i = 0; i < (1 << page_order); i++) {
+			DRM_DEBUG("page %d @ 0x%08lx\n",
+				  dma->page_count + page_count,
+				  page + PAGE_SIZE * i);
+			dma->pagelist[dma->page_count + page_count++]
+				= page + PAGE_SIZE * i;
+		}
+		for (offset = 0;
+		     offset + size <= total && entry->buf_count < count;
+		     offset += alignment, ++entry->buf_count) {
+			buf	     = &entry->buflist[entry->buf_count];
+			buf->idx     = dma->buf_count + entry->buf_count;
+			buf->total   = alignment;
+			buf->order   = order;
+			buf->used    = 0;
+			buf->offset  = (dma->byte_count + byte_count + offset);
+			buf->address = (void *)(page + offset);
+			buf->next    = NULL;
+			buf->waiting = 0;
+			buf->pending = 0;
+			init_waitqueue_head(&buf->dma_wait);
+			buf->pid     = 0;
+#if DRM_DMA_HISTOGRAM
+			buf->time_queued     = 0;
+			buf->time_dispatched = 0;
+			buf->time_completed  = 0;
+			buf->time_freed	     = 0;
+#endif
+			DRM_DEBUG("buffer %d @ %p\n",
+				  entry->buf_count, buf->address);
+		}
+		byte_count += PAGE_SIZE << page_order;
+	}
+
+	dma->buflist = drm_realloc(dma->buflist,
+				   dma->buf_count * sizeof(*dma->buflist),
+				   (dma->buf_count + entry->buf_count)
+				   * sizeof(*dma->buflist),
+				   DRM_MEM_BUFS);
+	for (i = dma->buf_count; i < dma->buf_count + entry->buf_count; i++)
+		dma->buflist[i] = &entry->buflist[i - dma->buf_count];
+
+	dma->buf_count	+= entry->buf_count;
+	dma->seg_count	+= entry->seg_count;
+	dma->page_count += entry->seg_count << page_order;
+	dma->byte_count += PAGE_SIZE * (entry->seg_count << page_order);
+	
+	drm_freelist_create(&entry->freelist, entry->buf_count);
+	for (i = 0; i < entry->buf_count; i++) {
+		drm_freelist_put(dev, &entry->freelist, &entry->buflist[i]);
+	}
+	
+	up(&dev->struct_sem);
+
+	request.count = entry->buf_count;
+	request.size  = size;
+
+	copy_to_user_ret((drm_buf_desc_t *)arg,
+			 &request,
+			 sizeof(request),
+			 -EFAULT);
+	
+	atomic_dec(&dev->buf_alloc);
+	return 0;
+}
+
+int mga_infobufs(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_device_dma_t *dma	 = dev->dma;
+	drm_buf_info_t	 request;
+	int		 i;
+	int		 count;
+
+	if (!dma) return -EINVAL;
+
+	spin_lock(&dev->count_lock);
+	if (atomic_read(&dev->buf_alloc)) {
+		spin_unlock(&dev->count_lock);
+		return -EBUSY;
+	}
+	++dev->buf_use;		/* Can't allocate more after this call */
+	spin_unlock(&dev->count_lock);
+
+	copy_from_user_ret(&request,
+			   (drm_buf_info_t *)arg,
+			   sizeof(request),
+			   -EFAULT);
+
+	for (i = 0, count = 0; i < DRM_MAX_ORDER+1; i++) {
+		if (dma->bufs[i].buf_count) ++count;
+	}
+	
+	DRM_DEBUG("count = %d\n", count);
+	
+	if (request.count >= count) {
+		for (i = 0, count = 0; i < DRM_MAX_ORDER+1; i++) {
+			if (dma->bufs[i].buf_count) {
+				copy_to_user_ret(&request.list[count].count,
+						 &dma->bufs[i].buf_count,
+						 sizeof(dma->bufs[0]
+							.buf_count),
+						 -EFAULT);
+				copy_to_user_ret(&request.list[count].size,
+						 &dma->bufs[i].buf_size,
+						 sizeof(dma->bufs[0].buf_size),
+						 -EFAULT);
+				copy_to_user_ret(&request.list[count].low_mark,
+						 &dma->bufs[i]
+						 .freelist.low_mark,
+						 sizeof(dma->bufs[0]
+							.freelist.low_mark),
+						 -EFAULT);
+				copy_to_user_ret(&request.list[count]
+						 .high_mark,
+						 &dma->bufs[i]
+						 .freelist.high_mark,
+						 sizeof(dma->bufs[0]
+							.freelist.high_mark),
+						 -EFAULT);
+				DRM_DEBUG("%d %d %d %d %d\n",
+					  i,
+					  dma->bufs[i].buf_count,
+					  dma->bufs[i].buf_size,
+					  dma->bufs[i].freelist.low_mark,
+					  dma->bufs[i].freelist.high_mark);
+				++count;
+			}
+		}
+	}
+	request.count = count;
+
+	copy_to_user_ret((drm_buf_info_t *)arg,
+			 &request,
+			 sizeof(request),
+			 -EFAULT);
+	
+	return 0;
+}
+
+int mga_markbufs(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_device_dma_t *dma	 = dev->dma;
+	drm_buf_desc_t	 request;
+	int		 order;
+	drm_buf_entry_t	 *entry;
+
+	if (!dma) return -EINVAL;
+
+	copy_from_user_ret(&request,
+			   (drm_buf_desc_t *)arg,
+			   sizeof(request),
+			   -EFAULT);
+
+	DRM_DEBUG("%d, %d, %d\n",
+		  request.size, request.low_mark, request.high_mark);
+	order = drm_order(request.size);
+	if (order < DRM_MIN_ORDER || order > DRM_MAX_ORDER) return -EINVAL;
+	entry = &dma->bufs[order];
+
+	if (request.low_mark < 0 || request.low_mark > entry->buf_count)
+		return -EINVAL;
+	if (request.high_mark < 0 || request.high_mark > entry->buf_count)
+		return -EINVAL;
+
+	entry->freelist.low_mark  = request.low_mark;
+	entry->freelist.high_mark = request.high_mark;
+	
+	return 0;
+}
+
+int mga_freebufs(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_device_dma_t *dma	 = dev->dma;
+	drm_buf_free_t	 request;
+	int		 i;
+	int		 idx;
+	drm_buf_t	 *buf;
+
+	if (!dma) return -EINVAL;
+
+	copy_from_user_ret(&request,
+			   (drm_buf_free_t *)arg,
+			   sizeof(request),
+			   -EFAULT);
+
+	DRM_DEBUG("%d\n", request.count);
+	for (i = 0; i < request.count; i++) {
+		copy_from_user_ret(&idx,
+				   &request.list[i],
+				   sizeof(idx),
+				   -EFAULT);
+		if (idx < 0 || idx >= dma->buf_count) {
+			DRM_ERROR("Index %d (of %d max)\n",
+				  idx, dma->buf_count - 1);
+			return -EINVAL;
+		}
+		buf = dma->buflist[idx];
+		if (buf->pid != current->pid) {
+			DRM_ERROR("Process %d freeing buffer owned by %d\n",
+				  current->pid, buf->pid);
+			return -EINVAL;
+		}
+		drm_free_buffer(dev, buf);
+	}
+	
+	return 0;
+}
+
+int mga_mapbufs(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_device_dma_t *dma	 = dev->dma;
+	int		 retcode = 0;
+	const int	 zero	 = 0;
+	unsigned long	 virtual;
+	unsigned long	 address;
+	drm_buf_map_t	 request;
+	int		 i;
+
+	if (!dma) return -EINVAL;
+	
+	DRM_DEBUG("\n");
+
+	spin_lock(&dev->count_lock);
+	if (atomic_read(&dev->buf_alloc)) {
+		spin_unlock(&dev->count_lock);
+		return -EBUSY;
+	}
+	++dev->buf_use;		/* Can't allocate more after this call */
+	spin_unlock(&dev->count_lock);
+
+	copy_from_user_ret(&request,
+			   (drm_buf_map_t *)arg,
+			   sizeof(request),
+			   -EFAULT);
+
+	if (request.count >= dma->buf_count) {
+		virtual = do_mmap(filp, 0, dma->byte_count,
+				  PROT_READ|PROT_WRITE, MAP_SHARED, 0);
+		if (virtual > -1024UL) {
+				/* Real error */
+			retcode = (signed long)virtual;
+			goto done;
+		}
+		request.virtual = (void *)virtual;
+
+		for (i = 0; i < dma->buf_count; i++) {
+			if (copy_to_user(&request.list[i].idx,
+					 &dma->buflist[i]->idx,
+					 sizeof(request.list[0].idx))) {
+				retcode = -EFAULT;
+				goto done;
+			}
+			if (copy_to_user(&request.list[i].total,
+					 &dma->buflist[i]->total,
+					 sizeof(request.list[0].total))) {
+				retcode = -EFAULT;
+				goto done;
+			}
+			if (copy_to_user(&request.list[i].used,
+					 &zero,
+					 sizeof(zero))) {
+				retcode = -EFAULT;
+				goto done;
+			}
+			address = virtual + dma->buflist[i]->offset;
+			if (copy_to_user(&request.list[i].address,
+					 &address,
+					 sizeof(address))) {
+				retcode = -EFAULT;
+				goto done;
+			}
+		}
+	}
+done:
+	request.count = dma->buf_count;
+	DRM_DEBUG("%d buffers, retcode = %d\n", request.count, retcode);
+
+	copy_to_user_ret((drm_buf_map_t *)arg,
+			 &request,
+			 sizeof(request),
+			 -EFAULT);
+
+	return retcode;
+}
diff --git a/linux/mga_context.c b/linux/mga_context.c
new file mode 100644
index 00000000..1745ad1e
--- /dev/null
+++ b/linux/mga_context.c
@@ -0,0 +1,210 @@
+/* mga_context.c -- IOCTLs for mga contexts -*- linux-c -*-
+ * Created: Thu Jan 6 01:42:46 2000 by jhartmann@precisioninsight.com
+ *
+ * Copyright 2000 Precision Insight, Inc., Cedar Park, Texas.
+ * 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.
+ * 
+ * Authors: Rickard E. (Rik) Faith <faith@precisioninsight.com>
+ *	    Jeff Hartmann <jhartmann@precisioninsight.com>
+ *
+ * $XFree86$
+ *
+ */
+
+#include <linux/sched.h>
+
+#define __NO_VERSION__
+#include "drmP.h"
+#include "mga_drv.h"
+
+extern drm_ctx_t mga_res_ctx;
+
+static int mga_alloc_queue(drm_device_t *dev)
+{
+	return drm_ctxbitmap_next(dev);
+}
+
+int mga_context_switch(drm_device_t *dev, int old, int new)
+{
+        char        buf[64];
+
+        atomic_inc(&dev->total_ctx);
+
+        if (test_and_set_bit(0, &dev->context_flag)) {
+                DRM_ERROR("Reentering -- FIXME\n");
+                return -EBUSY;
+        }
+
+#if DRM_DMA_HISTOGRAM
+        dev->ctx_start = get_cycles();
+#endif
+        
+        DRM_DEBUG("Context switch from %d to %d\n", old, new);
+
+        if (new == dev->last_context) {
+                clear_bit(0, &dev->context_flag);
+                return 0;
+        }
+        
+        if (drm_flags & DRM_FLAG_NOCTX) {
+                mga_context_switch_complete(dev, new);
+        } else {
+                sprintf(buf, "C %d %d\n", old, new);
+                drm_write_string(dev, buf);
+        }
+        
+        return 0;
+}
+
+int mga_context_switch_complete(drm_device_t *dev, int new)
+{
+        dev->last_context = new;  /* PRE/POST: This is the _only_ writer. */
+        dev->last_switch  = jiffies;
+        
+        if (!_DRM_LOCK_IS_HELD(dev->lock.hw_lock->lock)) {
+                DRM_ERROR("Lock isn't held after context switch\n");
+        }
+
+				/* If a context switch is ever initiated
+                                   when the kernel holds the lock, release
+                                   that lock here. */
+#if DRM_DMA_HISTOGRAM
+        atomic_inc(&dev->histo.ctx[drm_histogram_slot(get_cycles()
+                                                      - dev->ctx_start)]);
+                   
+#endif
+        clear_bit(0, &dev->context_flag);
+        wake_up(&dev->context_wait);
+        
+        return 0;
+}
+
+
+int mga_resctx(struct inode *inode, struct file *filp, unsigned int cmd,
+	       unsigned long arg)
+{
+	drm_ctx_res_t	res;
+	drm_ctx_t	ctx;
+	int		i;
+
+	DRM_DEBUG("%d\n", DRM_RESERVED_CONTEXTS);
+	copy_from_user_ret(&res, (drm_ctx_res_t *)arg, sizeof(res), -EFAULT);
+	if (res.count >= DRM_RESERVED_CONTEXTS) {
+		memset(&ctx, 0, sizeof(ctx));
+		for (i = 0; i < DRM_RESERVED_CONTEXTS; i++) {
+			ctx.handle = i;
+			copy_to_user_ret(&res.contexts[i],
+					 &i,
+					 sizeof(i),
+					 -EFAULT);
+		}
+	}
+	res.count = DRM_RESERVED_CONTEXTS;
+	copy_to_user_ret((drm_ctx_res_t *)arg, &res, sizeof(res), -EFAULT);
+	return 0;
+}
+
+
+int mga_addctx(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_ctx_t	ctx;
+
+	copy_from_user_ret(&ctx, (drm_ctx_t *)arg, sizeof(ctx), -EFAULT);
+	if ((ctx.handle = mga_alloc_queue(dev)) == DRM_KERNEL_CONTEXT) {
+				/* Skip kernel's context and get a new one. */
+		ctx.handle = mga_alloc_queue(dev);
+	}
+	DRM_DEBUG("%d\n", ctx.handle);
+	if (ctx.handle == -1) {
+		DRM_DEBUG("Not enough free contexts.\n");
+				/* Should this return -EBUSY instead? */
+		return -ENOMEM;
+	}
+	copy_to_user_ret((drm_ctx_t *)arg, &ctx, sizeof(ctx), -EFAULT);
+	return 0;
+}
+
+int mga_modctx(struct inode *inode, struct file *filp, unsigned int cmd,
+	unsigned long arg)
+{
+	drm_ctx_t ctx;
+
+	copy_from_user_ret(&ctx, (drm_ctx_t*)arg, sizeof(ctx), -EFAULT);
+	if (ctx.flags==_DRM_CONTEXT_PRESERVED)
+		mga_res_ctx.handle=ctx.handle;
+	return 0;
+}
+
+int mga_getctx(struct inode *inode, struct file *filp, unsigned int cmd,
+	unsigned long arg)
+{
+	drm_ctx_t ctx;
+
+	copy_from_user_ret(&ctx, (drm_ctx_t*)arg, sizeof(ctx), -EFAULT);
+	/* This is 0, because we don't hanlde any context flags */
+	ctx.flags = 0;
+	copy_to_user_ret((drm_ctx_t*)arg, &ctx, sizeof(ctx), -EFAULT);
+	return 0;
+}
+
+int mga_switchctx(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_ctx_t	ctx;
+
+	copy_from_user_ret(&ctx, (drm_ctx_t *)arg, sizeof(ctx), -EFAULT);
+	DRM_DEBUG("%d\n", ctx.handle);
+	return mga_context_switch(dev, dev->last_context, ctx.handle);
+}
+
+int mga_newctx(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_ctx_t	ctx;
+
+	copy_from_user_ret(&ctx, (drm_ctx_t *)arg, sizeof(ctx), -EFAULT);
+	DRM_DEBUG("%d\n", ctx.handle);
+	mga_context_switch_complete(dev, ctx.handle);
+
+	return 0;
+}
+
+int mga_rmctx(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_ctx_t	ctx;
+
+	copy_from_user_ret(&ctx, (drm_ctx_t *)arg, sizeof(ctx), -EFAULT);
+	DRM_DEBUG("%d\n", ctx.handle);
+	drm_ctxbitmap_free(dev, ctx.handle);
+	
+	return 0;
+}
diff --git a/linux/mga_dma.c b/linux/mga_dma.c
index 77821fa0..e2bc2119 100644
--- a/linux/mga_dma.c
+++ b/linux/mga_dma.c
@@ -1,6 +1,5 @@
-/* mga_dma.c -- DMA support for GMX 2000 -*- linux-c -*-
+/* mga_dma.c -- DMA support for mga g200/g400 -*- linux-c -*-
  * Created: Mon Dec 13 01:50:01 1999 by jhartmann@precisioninsight.com
- * Revised: Mon Dec 13 02:19:32 1999 by jhartmann@precisioninsight.com
  *
  * Copyright 1999 Precision Insight, Inc., Cedar Park, Texas.
  * All Rights Reserved.
@@ -23,7 +22,11 @@
  * 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.
- * 
+ *
+ * Authors: Rickard E. (Rik) Faith <faith@precisioninsight.com>
+ *	    Jeff Hartmann <jhartmann@precisioninsight.com>
+ *
+ * $XFree86$
  *
  */
 
diff --git a/linux/mga_drv.c b/linux/mga_drv.c
index 68083547..37ded285 100644
--- a/linux/mga_drv.c
+++ b/linux/mga_drv.c
@@ -1,6 +1,5 @@
 /* mga_drv.c -- Matrox g200/g400 driver -*- linux-c -*-
  * Created: Mon Dec 13 01:56:22 1999 by jhartmann@precisioninsight.com
- * Revised: Mon Dec 13 02:26:34 1999 by jhartmann@precisioninsight.com
  * 
  * Copyright 1999 Precision Insight, Inc., Cedar Park, Texas.
  * All Rights Reserved.
@@ -23,7 +22,11 @@
  * 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.
- * 
+ *
+ * Authors: Rickard E. (Rik) Faith <faith@precisioninsight.com>
+ *	    Jeff Hartmann <jhartmann@precisioninsight.com>
+ *
+ * $XFree86$
  *
  */
 
@@ -70,26 +73,36 @@ static drm_ioctl_desc_t	      mga_ioctls[] = {
 	[DRM_IOCTL_NR(DRM_IOCTL_CONTROL)]    = { mga_control,	  1, 1 },
 	[DRM_IOCTL_NR(DRM_IOCTL_AUTH_MAGIC)] = { drm_authmagic,	  1, 1 },
 	[DRM_IOCTL_NR(DRM_IOCTL_ADD_MAP)]    = { drm_addmap,	  1, 1 },
-	[DRM_IOCTL_NR(DRM_IOCTL_ADD_BUFS)]   = { drm_addbufs,	  1, 1 },
-	[DRM_IOCTL_NR(DRM_IOCTL_MARK_BUFS)]  = { drm_markbufs,	  1, 1 },
-	[DRM_IOCTL_NR(DRM_IOCTL_INFO_BUFS)]  = { drm_infobufs,	  1, 0 },
-	[DRM_IOCTL_NR(DRM_IOCTL_MAP_BUFS)]   = { drm_mapbufs,	  1, 0 },
-	[DRM_IOCTL_NR(DRM_IOCTL_FREE_BUFS)]  = { drm_freebufs,	  1, 0 },
-	
-	[DRM_IOCTL_NR(DRM_IOCTL_ADD_CTX)]    = { drm_addctx,	  1, 1 },
-	[DRM_IOCTL_NR(DRM_IOCTL_RM_CTX)]     = { drm_rmctx,	  1, 1 },
-	[DRM_IOCTL_NR(DRM_IOCTL_MOD_CTX)]    = { drm_modctx,	  1, 1 },
-	[DRM_IOCTL_NR(DRM_IOCTL_GET_CTX)]    = { drm_getctx,	  1, 0 },
-	[DRM_IOCTL_NR(DRM_IOCTL_SWITCH_CTX)] = { drm_switchctx,	  1, 1 },
-	[DRM_IOCTL_NR(DRM_IOCTL_NEW_CTX)]    = { drm_newctx,	  1, 1 },
-	[DRM_IOCTL_NR(DRM_IOCTL_RES_CTX)]    = { drm_resctx,	  1, 0 },
+	[DRM_IOCTL_NR(DRM_IOCTL_ADD_BUFS)]   = { mga_addbufs,	  1, 1 },
+	[DRM_IOCTL_NR(DRM_IOCTL_MARK_BUFS)]  = { mga_markbufs,	  1, 1 },
+	[DRM_IOCTL_NR(DRM_IOCTL_INFO_BUFS)]  = { mga_infobufs,	  1, 0 },
+	[DRM_IOCTL_NR(DRM_IOCTL_MAP_BUFS)]   = { mga_mapbufs,	  1, 0 },
+	[DRM_IOCTL_NR(DRM_IOCTL_FREE_BUFS)]  = { mga_freebufs,	  1, 0 },
+
+	[DRM_IOCTL_NR(DRM_IOCTL_ADD_CTX)]    = { mga_addctx,	  1, 1 },
+	[DRM_IOCTL_NR(DRM_IOCTL_RM_CTX)]     = { mga_rmctx,	  1, 1 },
+	[DRM_IOCTL_NR(DRM_IOCTL_MOD_CTX)]    = { mga_modctx,	  1, 1 },
+	[DRM_IOCTL_NR(DRM_IOCTL_GET_CTX)]    = { mga_getctx,	  1, 0 },
+	[DRM_IOCTL_NR(DRM_IOCTL_SWITCH_CTX)] = { mga_switchctx,	  1, 1 },
+	[DRM_IOCTL_NR(DRM_IOCTL_NEW_CTX)]    = { mga_newctx,	  1, 1 },
+	[DRM_IOCTL_NR(DRM_IOCTL_RES_CTX)]    = { mga_resctx,	  1, 0 },
 	[DRM_IOCTL_NR(DRM_IOCTL_ADD_DRAW)]   = { drm_adddraw,	  1, 1 },
 	[DRM_IOCTL_NR(DRM_IOCTL_RM_DRAW)]    = { drm_rmdraw,	  1, 1 },
 	[DRM_IOCTL_NR(DRM_IOCTL_DMA)]	     = { mga_dma,	  1, 0 },
 	[DRM_IOCTL_NR(DRM_IOCTL_LOCK)]	     = { mga_lock,	  1, 0 },
 	[DRM_IOCTL_NR(DRM_IOCTL_UNLOCK)]     = { mga_unlock,	  1, 0 },
 	[DRM_IOCTL_NR(DRM_IOCTL_FINISH)]     = { drm_finish,	  1, 0 },
+
+        [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, 1},
+        [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_unbind,  1, 1},
+        [DRM_IOCTL_NR(DRM_IOCTL_AGP_UNBIND)]	= {drm_agp_bind,    1, 1},
 };
+
 #define MGA_IOCTL_COUNT DRM_ARRAY_SIZE(mga_ioctls)
 
 #ifdef MODULE
@@ -269,6 +282,8 @@ static int mga_takedown(drm_device_t *dev)
 					       - PAGE_SHIFT,
 					       DRM_MEM_SAREA);
 				break;
+			case _DRM_AGP:
+				break;
 			}
 			drm_free(map, sizeof(*map), DRM_MEM_MAPS);
 		}
@@ -319,6 +334,10 @@ int mga_init(void)
 	DRM_DEBUG("\n");
 
 	memset((void *)dev, 0, sizeof(*dev));
+	if((retcode = drm_ctxbitmap_init(dev))) {
+		DRM_ERROR("Cannot allocate memory for context bitmap.\n");
+		return retcode;
+	}
 	dev->count_lock	  = SPIN_LOCK_UNLOCKED;
 	sema_init(&dev->struct_sem, 1);
 	
@@ -328,6 +347,7 @@ int mga_init(void)
 
 	if ((retcode = misc_register(&mga_misc))) {
 		DRM_ERROR("Cannot register \"%s\"\n", MGA_NAME);
+		drm_ctxbitmap_cleanup(dev);
 		return retcode;
 	}
 	dev->device = MKDEV(MISC_MAJOR, mga_misc.minor);
@@ -343,7 +363,9 @@ int mga_init(void)
 		 MGA_PATCHLEVEL,
 		 MGA_DATE,
 		 mga_misc.minor);
-	
+
+	dev->agp    = drm_agp_init();
+
 	return 0;
 }
 
@@ -362,6 +384,7 @@ void mga_cleanup(void)
 		DRM_INFO("Module unloaded\n");
 	}
 	mga_takedown(dev);
+	drm_ctxbitmap_cleanup(dev);
 }
 
 int mga_version(struct inode *inode, struct file *filp, unsigned int cmd,
@@ -484,6 +507,151 @@ int mga_ioctl(struct inode *inode, struct file *filp, unsigned int cmd,
 	return retcode;
 }
 
+int mga_lock(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;
+        DECLARE_WAITQUEUE(entry, current);
+        int               ret   = 0;
+        drm_lock_t        lock;
+#if DRM_DMA_HISTOGRAM
+        cycles_t          start;
+
+        dev->lck_start = start = get_cycles();
+#endif
+
+        copy_from_user_ret(&lock, (drm_lock_t *)arg, sizeof(lock), -EFAULT);
+
+        if (lock.context == DRM_KERNEL_CONTEXT) {
+                DRM_ERROR("Process %d using kernel context %d\n",
+                          current->pid, lock.context);
+                return -EINVAL;
+        }
+
+        DRM_DEBUG("%d (pid %d) requests lock (0x%08x), flags = 0x%08x\n",
+                  lock.context, current->pid, dev->lock.hw_lock->lock,
+                  lock.flags);
+
+#if 0
+				/* dev->queue_count == 0 right now for
+                                   mga.  FIXME? */
+        if (lock.context < 0 || lock.context >= dev->queue_count)
+                return -EINVAL;
+#endif
+        
+        if (!ret) {
+#if 0
+                if (_DRM_LOCKING_CONTEXT(dev->lock.hw_lock->lock)
+                    != lock.context) {
+                        long j = jiffies - dev->lock.lock_time;
+
+                        if (lock.context == mga_res_ctx.handle &&
+				j >= 0 && j < DRM_LOCK_SLICE) {
+                                /* Can't take lock if we just had it and
+                                   there is contention. */
+                                DRM_DEBUG("%d (pid %d) delayed j=%d dev=%d jiffies=%d\n",
+					lock.context, current->pid, j, 
+					dev->lock.lock_time, jiffies);
+                                current->state = TASK_INTERRUPTIBLE;
+				current->policy |= SCHED_YIELD;
+                                schedule_timeout(DRM_LOCK_SLICE-j);
+				DRM_DEBUG("jiffies=%d\n", jiffies);
+                        }
+                }
+#endif
+                add_wait_queue(&dev->lock.lock_queue, &entry);
+                for (;;) {
+                        if (!dev->lock.hw_lock) {
+                                /* Device has been unregistered */
+                                ret = -EINTR;
+                                break;
+                        }
+                        if (drm_lock_take(&dev->lock.hw_lock->lock,
+                                          lock.context)) {
+                                dev->lock.pid       = current->pid;
+                                dev->lock.lock_time = jiffies;
+                                atomic_inc(&dev->total_locks);
+                                break;  /* Got lock */
+                        }
+                        
+                                /* Contention */
+                        atomic_inc(&dev->total_sleeps);
+                        current->state = TASK_INTERRUPTIBLE;
+#if 1
+			current->policy |= SCHED_YIELD;
+#endif
+                        schedule();
+                        if (signal_pending(current)) {
+                                ret = -ERESTARTSYS;
+                                break;
+                        }
+                }
+                current->state = TASK_RUNNING;
+                remove_wait_queue(&dev->lock.lock_queue, &entry);
+        }
+
+#if 0
+	if (!ret && dev->last_context != lock.context &&
+		lock.context != mga_res_ctx.handle &&
+		dev->last_context != mga_res_ctx.handle) {
+		add_wait_queue(&dev->context_wait, &entry);
+	        current->state = TASK_INTERRUPTIBLE;
+                /* PRE: dev->last_context != lock.context */
+	        mga_context_switch(dev, dev->last_context, lock.context);
+		/* POST: we will wait for the context
+                   switch and will dispatch on a later call
+                   when dev->last_context == lock.context
+                   NOTE WE HOLD THE LOCK THROUGHOUT THIS
+                   TIME! */
+		current->policy |= SCHED_YIELD;
+	        schedule();
+	        current->state = TASK_RUNNING;
+	        remove_wait_queue(&dev->context_wait, &entry);
+	        if (signal_pending(current)) {
+	                ret = -EINTR;
+	        } else if (dev->last_context != lock.context) {
+			DRM_ERROR("Context mismatch: %d %d\n",
+                        	dev->last_context, lock.context);
+	        }
+	}
+#endif
+
+        if (!ret) {
+                if (lock.flags & _DRM_LOCK_READY) {
+				/* Wait for space in DMA/FIFO */
+		}
+                if (lock.flags & _DRM_LOCK_QUIESCENT) {
+				/* Make hardware quiescent */
+#if 0
+                        mga_quiescent(dev);
+#endif
+		}
+        }
+
+#if 0
+	DRM_ERROR("pid = %5d, old counter = %5ld\n", 
+		current->pid, current->counter);
+#endif
+	if (lock.context != mga_res_ctx.handle) {
+		current->counter = 5;
+		current->priority = DEF_PRIORITY/4;
+	}
+#if 0
+	while (current->counter > 25)
+		current->counter >>= 1; /* decrease time slice */
+	DRM_ERROR("pid = %5d, new counter = %5ld\n",
+		 current->pid, current->counter);
+#endif
+        DRM_DEBUG("%d %s\n", lock.context, ret ? "interrupted" : "has lock");
+
+#if DRM_DMA_HISTOGRAM
+        atomic_inc(&dev->histo.lacq[drm_histogram_slot(get_cycles() - start)]);
+#endif
+        
+        return ret;
+}
+
 
 int mga_unlock(struct inode *inode, struct file *filp, unsigned int cmd,
 		 unsigned long arg)
diff --git a/linux/mga_drv.h b/linux/mga_drv.h
index 2a3db9e8..e2370a9a 100644
--- a/linux/mga_drv.h
+++ b/linux/mga_drv.h
@@ -1,6 +1,5 @@
 /* mga_drv.h -- Private header for the Matrox g200/g400 driver -*- linux-c -*-
  * Created: Mon Dec 13 01:50:01 1999 by jhartmann@precisioninsight.com
- * Revised: Mon Dec 13 02:27:49 1999 by jhartmann@precisioninsight.com
  *
  * Copyright 1999 Precision Insight, Inc., Cedar Park, Texas.
  * All rights reserved.
@@ -23,8 +22,11 @@
  * 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.
- * 
- * 
+ *
+ * Authors: Rickard E. (Rik) Faith <faith@precisioninsight.com>
+ * 	    Jeff Hartmann <jhartmann@precisioninsight.com>
+ *
+ * $XFree86$
  */
 
 #ifndef _MGA_DRV_H_
@@ -53,6 +55,38 @@ extern int  mga_irq_uninstall(drm_device_t *dev);
 extern int  mga_control(struct inode *inode, struct file *filp,
 			  unsigned int cmd, unsigned long arg);
 
+				/* mga_bufs.c */
+extern int  mga_addbufs(struct inode *inode, struct file *filp, 
+			unsigned int cmd, unsigned long arg);
+extern int  mga_infobufs(struct inode *inode, struct file *filp, 
+			 unsigned int cmd, unsigned long arg);
+extern int  mga_markbufs(struct inode *inode, struct file *filp,
+			 unsigned int cmd, unsigned long arg);
+extern int  mga_freebufs(struct inode *inode, struct file *filp,
+			 unsigned int cmd, unsigned long arg);
+extern int  mga_mapbufs(struct inode *inode, struct file *filp,
+			unsigned int cmd, unsigned long arg);
+
+				/* mga_context.c */
+extern int  mga_resctx(struct inode *inode, struct file *filp,
+		       unsigned int cmd, unsigned long arg);
+extern int  mga_addctx(struct inode *inode, struct file *filp,
+		       unsigned int cmd, unsigned long arg);
+extern int  mga_modctx(struct inode *inode, struct file *filp,
+		       unsigned int cmd, unsigned long arg);
+extern int  mga_getctx(struct inode *inode, struct file *filp,
+		       unsigned int cmd, unsigned long arg);
+extern int  mga_switchctx(struct inode *inode, struct file *filp,
+			  unsigned int cmd, unsigned long arg);
+extern int  mga_newctx(struct inode *inode, struct file *filp,
+		       unsigned int cmd, unsigned long arg);
+extern int  mga_rmctx(struct inode *inode, struct file *filp,
+		      unsigned int cmd, unsigned long arg);
+
+extern int  mga_context_switch(drm_device_t *dev, int old, int new);
+extern int  mga_context_switch_complete(drm_device_t *dev, int new);
+
+
 #define MGAREG_MGA_EXEC 			0x0100
 #define MGAREG_AGP_PLL				0x1e4c
 #define MGAREG_ALPHACTRL 			0x2c7c