Previously, drm_get_resource_start() and drm_get_resource_len() would

    allocate the resource RF_ACTIVE, pull out the appropriate value, and
    return it. However, allocating large framebuffers RF_ACTIVE would run
    the system out of KVA, and this also left open the possibility of the
    resource getting moved after getting the offset. Instead, when either
    of these are called, allocate the resource if it isn't allocated
    already (non-RF_ACTIVE) and store it in the DRM device, to be cleaned
    up on lastclose.

3 files changed, 42 insertions, 27 deletions

diff --git a/bsd-core/drmP.h b/bsd-core/drmP.h
index d5907355..751714b6 100644
--- a/bsd-core/drmP.h
+++ b/bsd-core/drmP.h
@@ -686,6 +686,9 @@ struct drm_driver_info {
 	unsigned use_mtrr :1;
 };
 
+/* Length for the array of resource pointers for drm_get_resource_*. */
+#define DRM_MAX_PCI_RESOURCE	3
+
 /** 
  * DRM device functions structure
  */
@@ -748,6 +751,10 @@ struct drm_device {
 #endif
 	void		  *irqh;	/* Handle from bus_setup_intr      */
 
+	/* Storage of resource pointers for drm_get_resource_* */
+	struct resource   *pcir[DRM_MAX_PCI_RESOURCE];
+	int		  pcirid[DRM_MAX_PCI_RESOURCE];
+
 	int		  pci_domain;
 	int		  pci_bus;
 	int		  pci_slot;
diff --git a/bsd-core/drm_bufs.c b/bsd-core/drm_bufs.c
index 5ce2d4de..1df0238d 100644
--- a/bsd-core/drm_bufs.c
+++ b/bsd-core/drm_bufs.c
@@ -31,6 +31,8 @@
  *
  */
 
+#include "dev/pci/pcireg.h"
+
 #include "drmP.h"
 
 /*
@@ -49,46 +51,45 @@ int drm_order(unsigned long size)
 	return order;
 }
 
-unsigned long drm_get_resource_start(drm_device_t *dev, unsigned int resource)
+/* Allocation of PCI memory resources (framebuffer, registers, etc.) for
+ * drm_get_resource_*.  Note that they are not RF_ACTIVE, so there's no virtual
+ * address for accessing them.  Cleaned up at lastclose.
+ */
+static int drm_alloc_resource(drm_device_t *dev, int resource)
 {
-	struct resource *bsr;
-	unsigned long offset;
+	if (resource >= DRM_MAX_PCI_RESOURCE) {
+		DRM_ERROR("Resource %d too large\n", resource);
+		return 1;
+	}
+	if (dev->pcir[resource] != NULL)
+		return 0;
 
-	resource = resource * 4 + 0x10;
+	dev->pcirid[resource] = PCIR_BAR(resource);
+	dev->pcir[resource] = bus_alloc_resource_any(dev->device,
+	    SYS_RES_MEMORY, &dev->pcirid[resource], RF_SHAREABLE);
 
-	bsr = bus_alloc_resource_any(dev->device, SYS_RES_MEMORY, &resource,
-	    RF_ACTIVE | RF_SHAREABLE);
-	if (bsr == NULL) {
+	if (dev->pcir[resource] == NULL) {
 		DRM_ERROR("Couldn't find resource 0x%x\n", resource);
-		return 0;
+		return 1;
 	}
 
-	offset = rman_get_start(bsr);
+	return 0;
+}
 
-	bus_release_resource(dev->device, SYS_RES_MEMORY, resource, bsr);
+unsigned long drm_get_resource_start(drm_device_t *dev, unsigned int resource)
+{
+	if (drm_alloc_resource(dev, resource) != 0)
+		return 0;
 
-	return offset;
+	return rman_get_start(dev->pcir[resource]);
 }
 
 unsigned long drm_get_resource_len(drm_device_t *dev, unsigned int resource)
 {
-	struct resource *bsr;
-	unsigned long len;
-
-	resource = resource * 4 + 0x10;
-
-	bsr = bus_alloc_resource_any(dev->device, SYS_RES_MEMORY, &resource,
-	    RF_ACTIVE | RF_SHAREABLE);
-	if (bsr == NULL) {
-		DRM_ERROR("Couldn't find resource 0x%x\n", resource);
-		return ENOMEM;
-	}
-
-	len = rman_get_size(bsr);
-
-	bus_release_resource(dev->device, SYS_RES_MEMORY, resource, bsr);
+	if (drm_alloc_resource(dev, resource) != 0)
+		return 0;
 
-	return len;
+	return rman_get_size(dev->pcir[resource]);
 }
 
 int drm_addmap(drm_device_t * dev, unsigned long offset, unsigned long size,
diff --git a/bsd-core/drm_drv.c b/bsd-core/drm_drv.c
index c4ee39cb..63024132 100644
--- a/bsd-core/drm_drv.c
+++ b/bsd-core/drm_drv.c
@@ -474,6 +474,13 @@ static int drm_lastclose(drm_device_t *dev)
 	TAILQ_FOREACH_SAFE(map, &dev->maplist, link, mapsave) {
 		drm_rmmap(dev, map);
 	}
+	for (i = 0; i < DRM_MAX_PCI_RESOURCE; i++) {
+		if (dev->pcir[i] == NULL)
+			continue;
+		bus_release_resource(dev->device, SYS_RES_MEMORY,
+		    dev->pcirid[i], dev->pcir[i]);
+		dev->pcir[i] = NULL;
+	}
 
 	drm_dma_takedown(dev);
 	if ( dev->lock.hw_lock ) {