drm: Add the TTM GPU memory manager subsystem.
TTM is a GPU memory manager subsystem designed for use with GPU
devices with various memory types (On-card VRAM, AGP,
PCI apertures etc.). It's essentially a helper library that assists
the DRM driver in creating and managing persistent buffer objects.
TTM manages placement of data and CPU map setup and teardown on
data movement. It can also optionally manage synchronization of
data on a per-buffer-object level.
TTM takes care to provide an always valid virtual user-space address
to a buffer object which makes user-space sub-allocation of
big buffer objects feasible.
TTM uses a fine-grained per buffer-object locking scheme, taking
care to release all relevant locks when waiting for the GPU.
Although this implies some locking overhead, it's probably a big
win for devices with multiple command submission mechanisms, since
the lock contention will be minimal.
TTM can be used with whatever user-space interface the driver
chooses, including GEM. It's used by the upcoming Radeon KMS DRM driver
and is also the GPU memory management core of various new experimental
DRM drivers.
Signed-off-by: Thomas Hellstrom <thellstrom@vmware.com>
Signed-off-by: Jerome Glisse <jglisse@redhat.com>
Signed-off-by: Dave Airlie <airlied@redhat.com>
diff --git a/drivers/gpu/drm/ttm/ttm_global.c b/drivers/gpu/drm/ttm/ttm_global.c
new file mode 100644
index 0000000..0b14eb1
--- /dev/null
+++ b/drivers/gpu/drm/ttm/ttm_global.c
@@ -0,0 +1,114 @@
+/**************************************************************************
+ *
+ * Copyright 2008-2009 VMware, Inc., Palo Alto, CA., USA
+ * 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, sub license, 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 NON-INFRINGEMENT. IN NO EVENT SHALL
+ * THE COPYRIGHT HOLDERS, AUTHORS 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: Thomas Hellstrom <thellstrom-at-vmware-dot-com>
+ */
+
+#include "ttm/ttm_module.h"
+#include <linux/mutex.h>
+#include <linux/slab.h>
+#include <linux/module.h>
+
+struct ttm_global_item {
+ struct mutex mutex;
+ void *object;
+ int refcount;
+};
+
+static struct ttm_global_item glob[TTM_GLOBAL_NUM];
+
+void ttm_global_init(void)
+{
+ int i;
+
+ for (i = 0; i < TTM_GLOBAL_NUM; ++i) {
+ struct ttm_global_item *item = &glob[i];
+ mutex_init(&item->mutex);
+ item->object = NULL;
+ item->refcount = 0;
+ }
+}
+
+void ttm_global_release(void)
+{
+ int i;
+ for (i = 0; i < TTM_GLOBAL_NUM; ++i) {
+ struct ttm_global_item *item = &glob[i];
+ BUG_ON(item->object != NULL);
+ BUG_ON(item->refcount != 0);
+ }
+}
+
+int ttm_global_item_ref(struct ttm_global_reference *ref)
+{
+ int ret;
+ struct ttm_global_item *item = &glob[ref->global_type];
+ void *object;
+
+ mutex_lock(&item->mutex);
+ if (item->refcount == 0) {
+ item->object = kmalloc(ref->size, GFP_KERNEL);
+ if (unlikely(item->object == NULL)) {
+ ret = -ENOMEM;
+ goto out_err;
+ }
+
+ ref->object = item->object;
+ ret = ref->init(ref);
+ if (unlikely(ret != 0))
+ goto out_err;
+
+ ++item->refcount;
+ }
+ ref->object = item->object;
+ object = item->object;
+ mutex_unlock(&item->mutex);
+ return 0;
+out_err:
+ kfree(item->object);
+ mutex_unlock(&item->mutex);
+ item->object = NULL;
+ return ret;
+}
+EXPORT_SYMBOL(ttm_global_item_ref);
+
+void ttm_global_item_unref(struct ttm_global_reference *ref)
+{
+ struct ttm_global_item *item = &glob[ref->global_type];
+
+ mutex_lock(&item->mutex);
+ BUG_ON(item->refcount == 0);
+ BUG_ON(ref->object != item->object);
+ if (--item->refcount == 0) {
+ ref->release(ref);
+ kfree(item->object);
+ item->object = NULL;
+ }
+ mutex_unlock(&item->mutex);
+}
+EXPORT_SYMBOL(ttm_global_item_unref);
+