checkpoint: rename to GEM and a few more i915 bits.

1 files changed, 371 insertions, 0 deletions

diff --git a/linux-core/drm_gem.c b/linux-core/drm_gem.c
new file mode 100644
index 00000000..bd51362e
--- /dev/null
+++ b/linux-core/drm_gem.c
@@ -0,0 +1,371 @@
+/*
+ * Copyright © 2008 Intel Corporation
+ *
+ * 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
+ * THE AUTHORS OR COPYRIGHT HOLDERS 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:
+ *    Eric Anholt <eric@anholt.net>
+ *
+ */
+
+#include <linux/types.h>
+#include <linux/slab.h>
+#include <linux/mm.h>
+#include <linux/uaccess.h>
+#include <linux/fs.h>
+#include <linux/file.h>
+#include <linux/module.h>
+#include <linux/mman.h>
+#include <linux/pagemap.h>
+#include "drmP.h"
+
+/** @file drm_gem.c
+ *
+ * This file provides some of the base ioctls and library routines for
+ * the graphics memory manager implemented by each device driver.
+ *
+ * Because various devices have different requirements in terms of
+ * synchronization and migration strategies, implementing that is left up to
+ * the driver, and all that the general API provides should be generic --
+ * allocating objects, reading/writing data with the cpu, freeing objects.
+ * Even there, platform-dependent optimizations for reading/writing data with
+ * the CPU mean we'll likely hook those out to driver-specific calls.  However,
+ * the DRI2 implementation wants to have at least allocate/mmap be generic.
+ *
+ * The goal was to have swap-backed object allocation managed through
+ * struct file.  However, file descriptors as handles to a struct file have
+ * two major failings:
+ * - Process limits prevent more than 1024 or so being used at a time by
+ *   default.
+ * - Inability to allocate high fds will aggravate the X Server's select()
+ *   handling, and likely that of many GL client applications as well.
+ *
+ * This led to a plan of using our own integer IDs (called handles, following
+ * DRM terminology) to mimic fds, and implement the fd syscalls we need as
+ * ioctls.  The objects themselves will still include the struct file so
+ * that we can transition to fds if the required kernel infrastructure shows
+ * up at a later data, and as our interface with shmfs for memory allocation.
+ */
+
+static struct drm_gem_object *
+drm_gem_object_alloc(struct drm_device *dev, size_t size)
+{
+	struct drm_gem_object *obj;
+
+	BUG_ON((size & (PAGE_SIZE - 1)) != 0);
+
+	obj = kcalloc(1, sizeof(*obj), GFP_KERNEL);
+
+	obj->filp = shmem_file_setup("drm mm object", size, 0);
+	if (IS_ERR(obj->filp)) {
+		kfree(obj);
+		return NULL;
+	}
+
+	obj->refcount = 1;
+
+	if (dev->driver->gem_init_object != NULL &&
+	    dev->driver->gem_init_object(dev, obj) != 0) {
+		fput(obj->filp);
+		kfree(obj);
+		return NULL;
+	}
+	return obj;
+}
+
+/**
+ * Removes the mapping from handle to filp for this object.
+ */
+static int
+drm_gem_handle_delete(struct drm_device *dev, struct drm_file *filp,
+		      int handle)
+{
+	struct drm_gem_object *obj;
+
+	/* This is gross. The idr system doesn't let us try a delete and
+	 * return an error code.  It just spews if you fail at deleting.
+	 * So, we have to grab a lock around finding the object and then
+	 * doing the delete on it and dropping the refcount, or the user
+	 * could race us to double-decrement the refcount and cause a
+	 * use-after-free later.  Given the frequency of our handle lookups,
+	 * we may want to use ida for number allocation and a hash table
+	 * for the pointers, anyway.
+	 */
+	spin_lock(&filp->table_lock);
+
+	/* Check if we currently have a reference on the object */
+	obj = idr_find(&filp->object_idr, handle);
+	if (obj == NULL) {
+		spin_unlock(&filp->table_lock);
+		return -EINVAL;
+	}
+
+	/* Release reference and decrement refcount. */
+	idr_remove(&filp->object_idr, handle);
+	drm_gem_object_unreference(dev, obj);
+
+	spin_unlock(&filp->table_lock);
+
+	return 0;
+}
+
+/** Returns a reference to the object named by the handle. */
+static struct drm_gem_object *
+drm_gem_object_lookup(struct drm_device *dev, struct drm_file *filp,
+		      int handle)
+{
+	struct drm_gem_object *obj;
+
+	spin_lock(&filp->table_lock);
+
+	/* Check if we currently have a reference on the object */
+	obj = idr_find(&filp->object_idr, handle);
+	if (obj == NULL) {
+		spin_unlock(&filp->table_lock);
+		return NULL;
+	}
+
+	drm_gem_object_reference(dev, obj);
+
+	spin_unlock(&filp->table_lock);
+
+	return obj;
+}
+
+
+/**
+ * Allocates a new mm object and returns a handle to it.
+ */
+int
+drm_gem_alloc_ioctl(struct drm_device *dev, void *data,
+		    struct drm_file *file_priv)
+{
+	struct drm_gem_alloc_args *args = data;
+	struct drm_gem_object *obj;
+	int handle, ret;
+
+	/* Round requested size up to page size */
+	args->size = (args->size + PAGE_SIZE - 1) & ~(PAGE_SIZE - 1);
+
+	/* Allocate the new object */
+	obj = drm_gem_object_alloc(dev, args->size);
+	if (obj == NULL)
+		return -ENOMEM;
+
+	/* Get the user-visible handle using idr.
+	 *
+	 * I'm not really sure why the idr api needs us to do this in two
+	 * repeating steps.  It handles internal locking of its data
+	 * structure, yet insists that we keep its memory allocation step
+	 * separate from its slot-finding step for locking purposes.
+	 */
+	do {
+		if (idr_pre_get(&file_priv->object_idr, GFP_KERNEL) == 0) {
+			kfree(obj);
+			return -EFAULT;
+		}
+
+		ret = idr_get_new(&file_priv->object_idr, obj, &handle);
+	} while (ret == -EAGAIN);
+
+	if (ret != 0) {
+		drm_gem_object_unreference(dev, obj);
+		return -EFAULT;
+	}
+
+	args->handle = handle;
+
+	return 0;
+}
+
+/**
+ * Releases the handle to an mm object.
+ */
+int
+drm_gem_unreference_ioctl(struct drm_device *dev, void *data,
+			  struct drm_file *file_priv)
+{
+	struct drm_gem_unreference_args *args = data;
+	int ret;
+
+	ret = drm_gem_handle_delete(dev, file_priv, args->handle);
+
+	return ret;
+}
+
+/**
+ * Reads data from the object referenced by handle.
+ *
+ * On error, the contents of *data are undefined.
+ */
+int
+drm_gem_pread_ioctl(struct drm_device *dev, void *data,
+		    struct drm_file *file_priv)
+{
+	struct drm_gem_pread_args *args = data;
+	struct drm_gem_object *obj;
+	ssize_t read;
+	loff_t offset;
+
+	obj = drm_gem_object_lookup(dev, file_priv, args->handle);
+	if (obj == NULL)
+		return -EINVAL;
+
+	offset = args->offset;
+
+	read = obj->filp->f_op->read(obj->filp, (char __user *)args->data,
+				     args->size, &offset);
+	if (read != args->size) {
+		drm_gem_object_unreference(dev, obj);
+		if (read < 0)
+			return read;
+		else
+			return -EINVAL;
+	}
+
+	drm_gem_object_unreference(dev, obj);
+
+	return 0;
+}
+
+/**
+ * Maps the contents of an object, returning the address it is mapped
+ * into.
+ *
+ * While the mapping holds a reference on the contents of the object, it doesn't
+ * imply a ref on the object itself.
+ */
+int
+drm_gem_mmap_ioctl(struct drm_device *dev, void *data,
+		   struct drm_file *file_priv)
+{
+	struct drm_gem_mmap_args *args = data;
+	struct drm_gem_object *obj;
+	loff_t offset;
+
+	obj = drm_gem_object_lookup(dev, file_priv, args->handle);
+	if (obj == NULL)
+		return -EINVAL;
+
+	offset = args->offset;
+
+	down_write(&current->mm->mmap_sem);
+	args->addr = (void *)do_mmap(obj->filp, 0, args->size,
+				    PROT_READ | PROT_WRITE, MAP_SHARED,
+				    args->offset);
+	up_write(&current->mm->mmap_sem);
+
+	drm_gem_object_unreference(dev, obj);
+
+	return 0;
+}
+
+/**
+ * Writes data to the object referenced by handle.
+ *
+ * On error, the contents of the buffer that were to be modified are undefined.
+ */
+int
+drm_gem_pwrite_ioctl(struct drm_device *dev, void *data,
+		     struct drm_file *file_priv)
+{
+	struct drm_gem_pwrite_args *args = data;
+	struct drm_gem_object *obj;
+	ssize_t written;
+	loff_t offset;
+
+	obj = drm_gem_object_lookup(dev, file_priv, args->handle);
+	if (obj == NULL)
+		return -EINVAL;
+
+	offset = args->offset;
+
+	written = obj->filp->f_op->write(obj->filp, (char __user *)args->data,
+					 args->size, &offset);
+	if (written != args->size) {
+		drm_gem_object_unreference(dev, obj);
+		if (written < 0)
+			return written;
+		else
+			return -EINVAL;
+	}
+
+	drm_gem_object_unreference(dev, obj);
+
+	return 0;
+}
+
+/**
+ * Called at device open time, sets up the structure for handling refcounting
+ * of mm objects.
+ */
+void
+drm_gem_open(struct drm_device *dev, struct drm_file *file_private)
+{
+	idr_init(&file_private->object_idr);
+}
+
+/** Called at device close to release the file's references on objects. */
+static int
+drm_gem_object_release(int id, void *ptr, void *data)
+{
+	struct drm_device *dev = data;
+	struct drm_gem_object *obj = ptr;
+
+	drm_gem_object_unreference(dev, obj);
+
+	return 0;
+}
+
+/**
+ * Called at close time when the filp is going away.
+ *
+ * Releases any remaining references on objects by this filp.
+ */
+void
+drm_gem_release(struct drm_device *dev, struct drm_file *file_private)
+{
+	idr_for_each(&file_private->object_idr, &drm_gem_object_release, dev);
+
+	idr_destroy(&file_private->object_idr);
+}
+
+void
+drm_gem_object_reference(struct drm_device *dev, struct drm_gem_object *obj)
+{
+	spin_lock(&obj->lock);
+	obj->refcount++;
+	spin_unlock(&obj->lock);
+}
+
+void
+drm_gem_object_unreference(struct drm_device *dev, struct drm_gem_object *obj)
+{
+	spin_lock(&obj->lock);
+	obj->refcount--;
+	spin_unlock(&obj->lock);
+	if (obj->refcount == 0) {
+		if (dev->driver->gem_free_object != NULL)
+			dev->driver->gem_free_object(dev, obj);
+
+		fput(obj->filp);
+		kfree(obj);
+	}
+}