summaryrefslogtreecommitdiffstats
path: root/drivers/gpu/drm/vmwgfx/ttm_object.c
diff options
context:
space:
mode:
Diffstat (limited to 'drivers/gpu/drm/vmwgfx/ttm_object.c')
-rw-r--r--drivers/gpu/drm/vmwgfx/ttm_object.c671
1 files changed, 671 insertions, 0 deletions
diff --git a/drivers/gpu/drm/vmwgfx/ttm_object.c b/drivers/gpu/drm/vmwgfx/ttm_object.c
new file mode 100644
index 000000000..ddf8373c1
--- /dev/null
+++ b/drivers/gpu/drm/vmwgfx/ttm_object.c
@@ -0,0 +1,671 @@
+/* SPDX-License-Identifier: GPL-2.0 OR MIT */
+/**************************************************************************
+ *
+ * Copyright (c) 2009-2022 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>
+ *
+ * While no substantial code is shared, the prime code is inspired by
+ * drm_prime.c, with
+ * Authors:
+ * Dave Airlie <airlied@redhat.com>
+ * Rob Clark <rob.clark@linaro.org>
+ */
+/** @file ttm_ref_object.c
+ *
+ * Base- and reference object implementation for the various
+ * ttm objects. Implements reference counting, minimal security checks
+ * and release on file close.
+ */
+
+
+#define pr_fmt(fmt) "[TTM] " fmt
+
+#include "ttm_object.h"
+#include "vmwgfx_drv.h"
+
+#include <linux/list.h>
+#include <linux/spinlock.h>
+#include <linux/slab.h>
+#include <linux/atomic.h>
+#include <linux/module.h>
+#include <linux/hashtable.h>
+
+MODULE_IMPORT_NS(DMA_BUF);
+
+#define VMW_TTM_OBJECT_REF_HT_ORDER 10
+
+/**
+ * struct ttm_object_file
+ *
+ * @tdev: Pointer to the ttm_object_device.
+ *
+ * @lock: Lock that protects the ref_list list and the
+ * ref_hash hash tables.
+ *
+ * @ref_list: List of ttm_ref_objects to be destroyed at
+ * file release.
+ *
+ * @ref_hash: Hash tables of ref objects, one per ttm_ref_type,
+ * for fast lookup of ref objects given a base object.
+ *
+ * @refcount: reference/usage count
+ */
+struct ttm_object_file {
+ struct ttm_object_device *tdev;
+ spinlock_t lock;
+ struct list_head ref_list;
+ DECLARE_HASHTABLE(ref_hash, VMW_TTM_OBJECT_REF_HT_ORDER);
+ struct kref refcount;
+};
+
+/*
+ * struct ttm_object_device
+ *
+ * @object_lock: lock that protects idr.
+ *
+ * @object_count: Per device object count.
+ *
+ * This is the per-device data structure needed for ttm object management.
+ */
+
+struct ttm_object_device {
+ spinlock_t object_lock;
+ atomic_t object_count;
+ struct dma_buf_ops ops;
+ void (*dmabuf_release)(struct dma_buf *dma_buf);
+ struct idr idr;
+};
+
+/*
+ * struct ttm_ref_object
+ *
+ * @hash: Hash entry for the per-file object reference hash.
+ *
+ * @head: List entry for the per-file list of ref-objects.
+ *
+ * @kref: Ref count.
+ *
+ * @obj: Base object this ref object is referencing.
+ *
+ * @ref_type: Type of ref object.
+ *
+ * This is similar to an idr object, but it also has a hash table entry
+ * that allows lookup with a pointer to the referenced object as a key. In
+ * that way, one can easily detect whether a base object is referenced by
+ * a particular ttm_object_file. It also carries a ref count to avoid creating
+ * multiple ref objects if a ttm_object_file references the same base
+ * object more than once.
+ */
+
+struct ttm_ref_object {
+ struct rcu_head rcu_head;
+ struct vmwgfx_hash_item hash;
+ struct list_head head;
+ struct kref kref;
+ struct ttm_base_object *obj;
+ struct ttm_object_file *tfile;
+};
+
+static void ttm_prime_dmabuf_release(struct dma_buf *dma_buf);
+
+static inline struct ttm_object_file *
+ttm_object_file_ref(struct ttm_object_file *tfile)
+{
+ kref_get(&tfile->refcount);
+ return tfile;
+}
+
+static int ttm_tfile_find_ref_rcu(struct ttm_object_file *tfile,
+ uint64_t key,
+ struct vmwgfx_hash_item **p_hash)
+{
+ struct vmwgfx_hash_item *hash;
+
+ hash_for_each_possible_rcu(tfile->ref_hash, hash, head, key) {
+ if (hash->key == key) {
+ *p_hash = hash;
+ return 0;
+ }
+ }
+ return -EINVAL;
+}
+
+static int ttm_tfile_find_ref(struct ttm_object_file *tfile,
+ uint64_t key,
+ struct vmwgfx_hash_item **p_hash)
+{
+ struct vmwgfx_hash_item *hash;
+
+ hash_for_each_possible(tfile->ref_hash, hash, head, key) {
+ if (hash->key == key) {
+ *p_hash = hash;
+ return 0;
+ }
+ }
+ return -EINVAL;
+}
+
+static void ttm_object_file_destroy(struct kref *kref)
+{
+ struct ttm_object_file *tfile =
+ container_of(kref, struct ttm_object_file, refcount);
+
+ kfree(tfile);
+}
+
+
+static inline void ttm_object_file_unref(struct ttm_object_file **p_tfile)
+{
+ struct ttm_object_file *tfile = *p_tfile;
+
+ *p_tfile = NULL;
+ kref_put(&tfile->refcount, ttm_object_file_destroy);
+}
+
+
+int ttm_base_object_init(struct ttm_object_file *tfile,
+ struct ttm_base_object *base,
+ bool shareable,
+ enum ttm_object_type object_type,
+ void (*refcount_release) (struct ttm_base_object **))
+{
+ struct ttm_object_device *tdev = tfile->tdev;
+ int ret;
+
+ base->shareable = shareable;
+ base->tfile = ttm_object_file_ref(tfile);
+ base->refcount_release = refcount_release;
+ base->object_type = object_type;
+ kref_init(&base->refcount);
+ idr_preload(GFP_KERNEL);
+ spin_lock(&tdev->object_lock);
+ ret = idr_alloc(&tdev->idr, base, 1, 0, GFP_NOWAIT);
+ spin_unlock(&tdev->object_lock);
+ idr_preload_end();
+ if (ret < 0)
+ return ret;
+
+ base->handle = ret;
+ ret = ttm_ref_object_add(tfile, base, NULL, false);
+ if (unlikely(ret != 0))
+ goto out_err1;
+
+ ttm_base_object_unref(&base);
+
+ return 0;
+out_err1:
+ spin_lock(&tdev->object_lock);
+ idr_remove(&tdev->idr, base->handle);
+ spin_unlock(&tdev->object_lock);
+ return ret;
+}
+
+static void ttm_release_base(struct kref *kref)
+{
+ struct ttm_base_object *base =
+ container_of(kref, struct ttm_base_object, refcount);
+ struct ttm_object_device *tdev = base->tfile->tdev;
+
+ spin_lock(&tdev->object_lock);
+ idr_remove(&tdev->idr, base->handle);
+ spin_unlock(&tdev->object_lock);
+
+ /*
+ * Note: We don't use synchronize_rcu() here because it's far
+ * too slow. It's up to the user to free the object using
+ * call_rcu() or ttm_base_object_kfree().
+ */
+
+ ttm_object_file_unref(&base->tfile);
+ if (base->refcount_release)
+ base->refcount_release(&base);
+}
+
+void ttm_base_object_unref(struct ttm_base_object **p_base)
+{
+ struct ttm_base_object *base = *p_base;
+
+ *p_base = NULL;
+
+ kref_put(&base->refcount, ttm_release_base);
+}
+
+struct ttm_base_object *ttm_base_object_lookup(struct ttm_object_file *tfile,
+ uint64_t key)
+{
+ struct ttm_base_object *base = NULL;
+ struct vmwgfx_hash_item *hash;
+ int ret;
+
+ spin_lock(&tfile->lock);
+ ret = ttm_tfile_find_ref(tfile, key, &hash);
+
+ if (likely(ret == 0)) {
+ base = hlist_entry(hash, struct ttm_ref_object, hash)->obj;
+ if (!kref_get_unless_zero(&base->refcount))
+ base = NULL;
+ }
+ spin_unlock(&tfile->lock);
+
+
+ return base;
+}
+
+struct ttm_base_object *
+ttm_base_object_lookup_for_ref(struct ttm_object_device *tdev, uint64_t key)
+{
+ struct ttm_base_object *base;
+
+ rcu_read_lock();
+ base = idr_find(&tdev->idr, key);
+
+ if (base && !kref_get_unless_zero(&base->refcount))
+ base = NULL;
+ rcu_read_unlock();
+
+ return base;
+}
+
+int ttm_ref_object_add(struct ttm_object_file *tfile,
+ struct ttm_base_object *base,
+ bool *existed,
+ bool require_existed)
+{
+ struct ttm_ref_object *ref;
+ struct vmwgfx_hash_item *hash;
+ int ret = -EINVAL;
+
+ if (base->tfile != tfile && !base->shareable)
+ return -EPERM;
+
+ if (existed != NULL)
+ *existed = true;
+
+ while (ret == -EINVAL) {
+ rcu_read_lock();
+ ret = ttm_tfile_find_ref_rcu(tfile, base->handle, &hash);
+
+ if (ret == 0) {
+ ref = hlist_entry(hash, struct ttm_ref_object, hash);
+ if (kref_get_unless_zero(&ref->kref)) {
+ rcu_read_unlock();
+ break;
+ }
+ }
+
+ rcu_read_unlock();
+ if (require_existed)
+ return -EPERM;
+
+ ref = kmalloc(sizeof(*ref), GFP_KERNEL);
+ if (unlikely(ref == NULL)) {
+ return -ENOMEM;
+ }
+
+ ref->hash.key = base->handle;
+ ref->obj = base;
+ ref->tfile = tfile;
+ kref_init(&ref->kref);
+
+ spin_lock(&tfile->lock);
+ hash_add_rcu(tfile->ref_hash, &ref->hash.head, ref->hash.key);
+ ret = 0;
+
+ list_add_tail(&ref->head, &tfile->ref_list);
+ kref_get(&base->refcount);
+ spin_unlock(&tfile->lock);
+ if (existed != NULL)
+ *existed = false;
+ }
+
+ return ret;
+}
+
+static void __releases(tfile->lock) __acquires(tfile->lock)
+ttm_ref_object_release(struct kref *kref)
+{
+ struct ttm_ref_object *ref =
+ container_of(kref, struct ttm_ref_object, kref);
+ struct ttm_object_file *tfile = ref->tfile;
+
+ hash_del_rcu(&ref->hash.head);
+ list_del(&ref->head);
+ spin_unlock(&tfile->lock);
+
+ ttm_base_object_unref(&ref->obj);
+ kfree_rcu(ref, rcu_head);
+ spin_lock(&tfile->lock);
+}
+
+int ttm_ref_object_base_unref(struct ttm_object_file *tfile,
+ unsigned long key)
+{
+ struct ttm_ref_object *ref;
+ struct vmwgfx_hash_item *hash;
+ int ret;
+
+ spin_lock(&tfile->lock);
+ ret = ttm_tfile_find_ref(tfile, key, &hash);
+ if (unlikely(ret != 0)) {
+ spin_unlock(&tfile->lock);
+ return -EINVAL;
+ }
+ ref = hlist_entry(hash, struct ttm_ref_object, hash);
+ kref_put(&ref->kref, ttm_ref_object_release);
+ spin_unlock(&tfile->lock);
+ return 0;
+}
+
+void ttm_object_file_release(struct ttm_object_file **p_tfile)
+{
+ struct ttm_ref_object *ref;
+ struct list_head *list;
+ struct ttm_object_file *tfile = *p_tfile;
+
+ *p_tfile = NULL;
+ spin_lock(&tfile->lock);
+
+ /*
+ * Since we release the lock within the loop, we have to
+ * restart it from the beginning each time.
+ */
+
+ while (!list_empty(&tfile->ref_list)) {
+ list = tfile->ref_list.next;
+ ref = list_entry(list, struct ttm_ref_object, head);
+ ttm_ref_object_release(&ref->kref);
+ }
+
+ spin_unlock(&tfile->lock);
+
+ ttm_object_file_unref(&tfile);
+}
+
+struct ttm_object_file *ttm_object_file_init(struct ttm_object_device *tdev)
+{
+ struct ttm_object_file *tfile = kmalloc(sizeof(*tfile), GFP_KERNEL);
+
+ if (unlikely(tfile == NULL))
+ return NULL;
+
+ spin_lock_init(&tfile->lock);
+ tfile->tdev = tdev;
+ kref_init(&tfile->refcount);
+ INIT_LIST_HEAD(&tfile->ref_list);
+
+ hash_init(tfile->ref_hash);
+
+ return tfile;
+}
+
+struct ttm_object_device *
+ttm_object_device_init(const struct dma_buf_ops *ops)
+{
+ struct ttm_object_device *tdev = kmalloc(sizeof(*tdev), GFP_KERNEL);
+
+ if (unlikely(tdev == NULL))
+ return NULL;
+
+ spin_lock_init(&tdev->object_lock);
+ atomic_set(&tdev->object_count, 0);
+
+ /*
+ * Our base is at VMWGFX_NUM_MOB + 1 because we want to create
+ * a seperate namespace for GEM handles (which are
+ * 1..VMWGFX_NUM_MOB) and the surface handles. Some ioctl's
+ * can take either handle as an argument so we want to
+ * easily be able to tell whether the handle refers to a
+ * GEM buffer or a surface.
+ */
+ idr_init_base(&tdev->idr, VMWGFX_NUM_MOB + 1);
+ tdev->ops = *ops;
+ tdev->dmabuf_release = tdev->ops.release;
+ tdev->ops.release = ttm_prime_dmabuf_release;
+ return tdev;
+}
+
+void ttm_object_device_release(struct ttm_object_device **p_tdev)
+{
+ struct ttm_object_device *tdev = *p_tdev;
+
+ *p_tdev = NULL;
+
+ WARN_ON_ONCE(!idr_is_empty(&tdev->idr));
+ idr_destroy(&tdev->idr);
+
+ kfree(tdev);
+}
+
+/**
+ * get_dma_buf_unless_doomed - get a dma_buf reference if possible.
+ *
+ * @dmabuf: Non-refcounted pointer to a struct dma-buf.
+ *
+ * Obtain a file reference from a lookup structure that doesn't refcount
+ * the file, but synchronizes with its release method to make sure it has
+ * not been freed yet. See for example kref_get_unless_zero documentation.
+ * Returns true if refcounting succeeds, false otherwise.
+ *
+ * Nobody really wants this as a public API yet, so let it mature here
+ * for some time...
+ */
+static bool __must_check get_dma_buf_unless_doomed(struct dma_buf *dmabuf)
+{
+ return atomic_long_inc_not_zero(&dmabuf->file->f_count) != 0L;
+}
+
+/**
+ * ttm_prime_refcount_release - refcount release method for a prime object.
+ *
+ * @p_base: Pointer to ttm_base_object pointer.
+ *
+ * This is a wrapper that calls the refcount_release founction of the
+ * underlying object. At the same time it cleans up the prime object.
+ * This function is called when all references to the base object we
+ * derive from are gone.
+ */
+static void ttm_prime_refcount_release(struct ttm_base_object **p_base)
+{
+ struct ttm_base_object *base = *p_base;
+ struct ttm_prime_object *prime;
+
+ *p_base = NULL;
+ prime = container_of(base, struct ttm_prime_object, base);
+ BUG_ON(prime->dma_buf != NULL);
+ mutex_destroy(&prime->mutex);
+ if (prime->refcount_release)
+ prime->refcount_release(&base);
+}
+
+/**
+ * ttm_prime_dmabuf_release - Release method for the dma-bufs we export
+ *
+ * @dma_buf:
+ *
+ * This function first calls the dma_buf release method the driver
+ * provides. Then it cleans up our dma_buf pointer used for lookup,
+ * and finally releases the reference the dma_buf has on our base
+ * object.
+ */
+static void ttm_prime_dmabuf_release(struct dma_buf *dma_buf)
+{
+ struct ttm_prime_object *prime =
+ (struct ttm_prime_object *) dma_buf->priv;
+ struct ttm_base_object *base = &prime->base;
+ struct ttm_object_device *tdev = base->tfile->tdev;
+
+ if (tdev->dmabuf_release)
+ tdev->dmabuf_release(dma_buf);
+ mutex_lock(&prime->mutex);
+ if (prime->dma_buf == dma_buf)
+ prime->dma_buf = NULL;
+ mutex_unlock(&prime->mutex);
+ ttm_base_object_unref(&base);
+}
+
+/**
+ * ttm_prime_fd_to_handle - Get a base object handle from a prime fd
+ *
+ * @tfile: A struct ttm_object_file identifying the caller.
+ * @fd: The prime / dmabuf fd.
+ * @handle: The returned handle.
+ *
+ * This function returns a handle to an object that previously exported
+ * a dma-buf. Note that we don't handle imports yet, because we simply
+ * have no consumers of that implementation.
+ */
+int ttm_prime_fd_to_handle(struct ttm_object_file *tfile,
+ int fd, u32 *handle)
+{
+ struct ttm_object_device *tdev = tfile->tdev;
+ struct dma_buf *dma_buf;
+ struct ttm_prime_object *prime;
+ struct ttm_base_object *base;
+ int ret;
+
+ dma_buf = dma_buf_get(fd);
+ if (IS_ERR(dma_buf))
+ return PTR_ERR(dma_buf);
+
+ if (dma_buf->ops != &tdev->ops)
+ return -ENOSYS;
+
+ prime = (struct ttm_prime_object *) dma_buf->priv;
+ base = &prime->base;
+ *handle = base->handle;
+ ret = ttm_ref_object_add(tfile, base, NULL, false);
+
+ dma_buf_put(dma_buf);
+
+ return ret;
+}
+
+/**
+ * ttm_prime_handle_to_fd - Return a dma_buf fd from a ttm prime object
+ *
+ * @tfile: Struct ttm_object_file identifying the caller.
+ * @handle: Handle to the object we're exporting from.
+ * @flags: flags for dma-buf creation. We just pass them on.
+ * @prime_fd: The returned file descriptor.
+ *
+ */
+int ttm_prime_handle_to_fd(struct ttm_object_file *tfile,
+ uint32_t handle, uint32_t flags,
+ int *prime_fd)
+{
+ struct ttm_object_device *tdev = tfile->tdev;
+ struct ttm_base_object *base;
+ struct dma_buf *dma_buf;
+ struct ttm_prime_object *prime;
+ int ret;
+
+ base = ttm_base_object_lookup(tfile, handle);
+ if (unlikely(base == NULL ||
+ base->object_type != ttm_prime_type)) {
+ ret = -ENOENT;
+ goto out_unref;
+ }
+
+ prime = container_of(base, struct ttm_prime_object, base);
+ if (unlikely(!base->shareable)) {
+ ret = -EPERM;
+ goto out_unref;
+ }
+
+ ret = mutex_lock_interruptible(&prime->mutex);
+ if (unlikely(ret != 0)) {
+ ret = -ERESTARTSYS;
+ goto out_unref;
+ }
+
+ dma_buf = prime->dma_buf;
+ if (!dma_buf || !get_dma_buf_unless_doomed(dma_buf)) {
+ DEFINE_DMA_BUF_EXPORT_INFO(exp_info);
+ exp_info.ops = &tdev->ops;
+ exp_info.size = prime->size;
+ exp_info.flags = flags;
+ exp_info.priv = prime;
+
+ /*
+ * Need to create a new dma_buf
+ */
+
+ dma_buf = dma_buf_export(&exp_info);
+ if (IS_ERR(dma_buf)) {
+ ret = PTR_ERR(dma_buf);
+ mutex_unlock(&prime->mutex);
+ goto out_unref;
+ }
+
+ /*
+ * dma_buf has taken the base object reference
+ */
+ base = NULL;
+ prime->dma_buf = dma_buf;
+ }
+ mutex_unlock(&prime->mutex);
+
+ ret = dma_buf_fd(dma_buf, flags);
+ if (ret >= 0) {
+ *prime_fd = ret;
+ ret = 0;
+ } else
+ dma_buf_put(dma_buf);
+
+out_unref:
+ if (base)
+ ttm_base_object_unref(&base);
+ return ret;
+}
+
+/**
+ * ttm_prime_object_init - Initialize a ttm_prime_object
+ *
+ * @tfile: struct ttm_object_file identifying the caller
+ * @size: The size of the dma_bufs we export.
+ * @prime: The object to be initialized.
+ * @shareable: See ttm_base_object_init
+ * @type: See ttm_base_object_init
+ * @refcount_release: See ttm_base_object_init
+ *
+ * Initializes an object which is compatible with the drm_prime model
+ * for data sharing between processes and devices.
+ */
+int ttm_prime_object_init(struct ttm_object_file *tfile, size_t size,
+ struct ttm_prime_object *prime, bool shareable,
+ enum ttm_object_type type,
+ void (*refcount_release) (struct ttm_base_object **))
+{
+ mutex_init(&prime->mutex);
+ prime->size = PAGE_ALIGN(size);
+ prime->real_type = type;
+ prime->dma_buf = NULL;
+ prime->refcount_release = refcount_release;
+ return ttm_base_object_init(tfile, &prime->base, shareable,
+ ttm_prime_type,
+ ttm_prime_refcount_release);
+}