Refine the locking of the DRM. Most significant is covering the driver

    ioctls with dev_lock, which is a major step toward being able to remove
    Giant. Covers some new pieces (dev->unique*) in the core, and avoids
    one call down into system internals with the drm lock held, which is
    usually bad (FreeBSD LOR #23, #27).

1 files changed, 35 insertions, 40 deletions

diff --git a/bsd-core/drm_vm.c b/bsd-core/drm_vm.c
index f3558b9e..1b5d4d3f 100644
--- a/bsd-core/drm_vm.c
+++ b/bsd-core/drm_vm.c
@@ -26,35 +26,6 @@
 #include "drm.h"
 
 #if defined(__FreeBSD__) && __FreeBSD_version >= 500102
-static int drm_dma_mmap(struct cdev *kdev, vm_offset_t offset,
-    vm_paddr_t *paddr, int prot)
-#elif defined(__FreeBSD__)
-static int drm_dma_mmap(dev_t kdev, vm_offset_t offset, int prot)
-#elif defined(__NetBSD__) || defined(__OpenBSD__)
-static paddr_t drm_dma_mmap(dev_t kdev, vm_offset_t offset, int prot)
-#endif
-{
-	DRM_DEVICE;
-	drm_device_dma_t *dma = dev->dma;
-	unsigned long physical;
-	unsigned long page;
-
-	if (dma == NULL || dma->pagelist == NULL)
-		return -1;
-
-	page	 = offset >> PAGE_SHIFT;
-	physical = dma->pagelist[page];
-
-	DRM_DEBUG("0x%08lx (page %lu) => 0x%08lx\n", (long)offset, page, physical);
-#if defined(__FreeBSD__) && __FreeBSD_version >= 500102
-	*paddr = physical;
-	return 0;
-#else
-	return atop(physical);
-#endif
-}
-
-#if defined(__FreeBSD__) && __FreeBSD_version >= 500102
 int drm_mmap(struct cdev *kdev, vm_offset_t offset, vm_paddr_t *paddr, 
     int prot)
 #elif defined(__FreeBSD__)
@@ -67,20 +38,40 @@ paddr_t drm_mmap(dev_t kdev, off_t offset, int prot)
 	drm_local_map_t *map = NULL;
 	drm_map_list_entry_t *listentry = NULL;
 	drm_file_t *priv;
+	drm_map_type_t type;
 
-	DRM_GET_PRIV_WITH_RETURN(priv, (DRMFILE)(uintptr_t)DRM_CURRENTPID);
+	DRM_LOCK();
+	priv = drm_find_file_by_proc(dev, DRM_CURPROC);
+	DRM_UNLOCK();
+	if (priv == NULL) {
+		DRM_ERROR("can't find authenticator\n");
+		return EINVAL;
+	}
 
 	if (!priv->authenticated)
 		return DRM_ERR(EACCES);
 
-	if (dev->dma
-	    && offset >= 0
-	    && offset < ptoa(dev->dma->page_count))
+	DRM_SPINLOCK(&dev->dma_lock);
+	if (dev->dma && offset >= 0 && offset < ptoa(dev->dma->page_count)) {
+		drm_device_dma_t *dma = dev->dma;
+
+		if (dma->pagelist != NULL) {
+			unsigned long page = offset >> PAGE_SHIFT;
+			unsigned long phys = dma->pagelist[page];
+
 #if defined(__FreeBSD__) && __FreeBSD_version >= 500102
-		return drm_dma_mmap(kdev, offset, paddr, prot);
+			*paddr = phys;
+			DRM_SPINUNLOCK(&dev->dma_lock);
+			return 0;
 #else
-		return drm_dma_mmap(kdev, offset, prot);
-#endif
+			return atop(phys);
+#endif		
+		} else {
+			DRM_SPINUNLOCK(&dev->dma_lock);
+			return -1;
+		}
+	}
+	DRM_SPINUNLOCK(&dev->dma_lock);
 
 				/* A sequential search of a linked list is
 				   fine here because: 1) there will only be
@@ -89,23 +80,27 @@ paddr_t drm_mmap(dev_t kdev, off_t offset, int prot)
 				   once, so it doesn't have to be optimized
 				   for performance, even if the list was a
 				   bit longer. */
+	DRM_LOCK();
 	TAILQ_FOREACH(listentry, dev->maplist, link) {
 		map = listentry->map;
-/*		DRM_DEBUG("considering 0x%x..0x%x\n", map->offset, map->offset + map->size - 1);*/
-		if (offset >= map->offset
-		    && offset < map->offset + map->size) break;
+		if (offset >= map->offset && offset < map->offset + map->size)
+			break;
 	}
 	
 	if (!listentry) {
+		DRM_UNLOCK();
 		DRM_DEBUG("can't find map\n");
 		return -1;
 	}
 	if (((map->flags&_DRM_RESTRICTED) && DRM_SUSER(DRM_CURPROC))) {
+		DRM_UNLOCK();
 		DRM_DEBUG("restricted map\n");
 		return -1;
 	}
+	type = map->type;
+	DRM_UNLOCK();
 
-	switch (map->type) {
+	switch (type) {
 	case _DRM_FRAME_BUFFER:
 	case _DRM_REGISTERS:
 	case _DRM_AGP: