Signed-off-by: Thomas Hellstrom thellstrom@vmware.com Reviewed-by: Jakob Bornecrantz jakob@vmware.com --- drivers/gpu/drm/ttm/ttm_object.c | 254 +++++++++++++++++++++++++++++++++++++- include/drm/ttm/ttm_object.h | 61 ++++++++- 2 files changed, 307 insertions(+), 8 deletions(-)
diff --git a/drivers/gpu/drm/ttm/ttm_object.c b/drivers/gpu/drm/ttm/ttm_object.c index a868176..6fe7b92 100644 --- a/drivers/gpu/drm/ttm/ttm_object.c +++ b/drivers/gpu/drm/ttm/ttm_object.c @@ -1,6 +1,6 @@ /************************************************************************** * - * Copyright (c) 2009 VMware, Inc., Palo Alto, CA., USA + * Copyright (c) 2009-2013 VMware, Inc., Palo Alto, CA., USA * All Rights Reserved. * * Permission is hereby granted, free of charge, to any person obtaining a @@ -26,6 +26,12 @@ **************************************************************************/ /* * 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 * @@ -34,6 +40,7 @@ * and release on file close. */
+ /** * struct ttm_object_file * @@ -84,6 +91,9 @@ struct ttm_object_device { struct drm_open_hash object_hash; atomic_t object_count; struct ttm_mem_global *mem_glob; + struct dma_buf_ops ops; + void (*dmabuf_release)(struct dma_buf *dma_buf); + size_t dma_buf_size; };
/** @@ -116,6 +126,8 @@ struct ttm_ref_object { 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) { @@ -416,9 +428,10 @@ out_err: } EXPORT_SYMBOL(ttm_object_file_init);
-struct ttm_object_device *ttm_object_device_init(struct ttm_mem_global - *mem_glob, - unsigned int hash_order) +struct ttm_object_device * +ttm_object_device_init(struct ttm_mem_global *mem_glob, + unsigned int hash_order, + const struct dma_buf_ops *ops) { struct ttm_object_device *tdev = kmalloc(sizeof(*tdev), GFP_KERNEL); int ret; @@ -430,10 +443,17 @@ struct ttm_object_device *ttm_object_device_init(struct ttm_mem_global spin_lock_init(&tdev->object_lock); atomic_set(&tdev->object_count, 0); ret = drm_ht_create(&tdev->object_hash, hash_order); + if (ret != 0) + goto out_no_object_hash;
- if (likely(ret == 0)) - return tdev; + tdev->ops = *ops; + tdev->dmabuf_release = tdev->ops.release; + tdev->ops.release = ttm_prime_dmabuf_release; + tdev->dma_buf_size = ttm_round_pot(sizeof(struct dma_buf)) + + ttm_round_pot(sizeof(struct file)); + return tdev;
+out_no_object_hash: kfree(tdev); return NULL; } @@ -452,3 +472,225 @@ void ttm_object_device_release(struct ttm_object_device **p_tdev) kfree(tdev); } EXPORT_SYMBOL(ttm_object_device_release); + +/** + * get_dma_buf_unless_doomed - get a dma_buf reference if possible. + * + * @dma_buf: 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_mem_global_free(tdev->mem_glob, tdev->dma_buf_size); + 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->hash.key; + ret = ttm_ref_object_add(tfile, base, TTM_REF_USAGE, NULL); + + dma_buf_put(dma_buf); + + return ret; +} +EXPORT_SYMBOL_GPL(ttm_prime_fd_to_handle); + +/** + * 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)) { + + /* + * Need to create a new dma_buf, with memory accounting. + */ + ret = ttm_mem_global_alloc(tdev->mem_glob, tdev->dma_buf_size, + false, true); + if (unlikely(ret != 0)) { + mutex_unlock(&prime->mutex); + goto out_unref; + } + + dma_buf = dma_buf_export(prime, &tdev->ops, + prime->size, flags); + if (IS_ERR(dma_buf)) { + ret = PTR_ERR(dma_buf); + ttm_mem_global_free(tdev->mem_glob, + tdev->dma_buf_size); + 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; +} +EXPORT_SYMBOL_GPL(ttm_prime_handle_to_fd); + +/** + * 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 + * @ref_obj_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 **), + void (*ref_obj_release) (struct ttm_base_object *, + enum ttm_ref_type ref_type)) +{ + 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, + ref_obj_release); +} +EXPORT_SYMBOL(ttm_prime_object_init); diff --git a/include/drm/ttm/ttm_object.h b/include/drm/ttm/ttm_object.h index fc0cf06..58b0298 100644 --- a/include/drm/ttm/ttm_object.h +++ b/include/drm/ttm/ttm_object.h @@ -41,6 +41,7 @@ #include <drm/drm_hashtab.h> #include <linux/kref.h> #include <linux/rcupdate.h> +#include <linux/dma-buf.h> #include <ttm/ttm_memory.h>
/** @@ -77,6 +78,7 @@ enum ttm_object_type { ttm_fence_type, ttm_buffer_type, ttm_lock_type, + ttm_prime_type, ttm_driver_type0 = 256, ttm_driver_type1, ttm_driver_type2, @@ -132,6 +134,30 @@ struct ttm_base_object { enum ttm_ref_type ref_type); };
+ +/** + * struct ttm_prime_object - Modified base object that is prime-aware + * + * @base: struct ttm_base_object that we derive from + * @mutex: Mutex protecting the @dma_buf member. + * @size: Size of the dma_buf associated with this object + * @real_type: Type of the underlying object. Needed since we're setting + * the value of @base::object_type to ttm_prime_type + * @dma_buf: Non ref-coutned pointer to a struct dma_buf created from this + * object. + * @refcount_release: The underlying object's release method. Needed since + * we set @base::refcount_release to our own release method. + */ + +struct ttm_prime_object { + struct ttm_base_object base; + struct mutex mutex; + size_t size; + enum ttm_object_type real_type; + struct dma_buf *dma_buf; + void (*refcount_release) (struct ttm_base_object **); +}; + /** * ttm_base_object_init * @@ -248,14 +274,18 @@ extern void ttm_object_file_release(struct ttm_object_file **p_tfile); /** * ttm_object device init - initialize a struct ttm_object_device * + * @mem_glob: struct ttm_mem_global for memory accounting. * @hash_order: Order of hash table used to hash the base objects. + * @ops: DMA buf ops for prime objects of this device. * * This function is typically called on device initialization to prepare * data structures needed for ttm base and ref objects. */
-extern struct ttm_object_device *ttm_object_device_init - (struct ttm_mem_global *mem_glob, unsigned int hash_order); +extern struct ttm_object_device * +ttm_object_device_init(struct ttm_mem_global *mem_glob, + unsigned int hash_order, + const struct dma_buf_ops *ops);
/** * ttm_object_device_release - release data held by a ttm_object_device @@ -272,4 +302,31 @@ extern void ttm_object_device_release(struct ttm_object_device **p_tdev);
#define ttm_base_object_kfree(__object, __base)\ kfree_rcu(__object, __base.rhead) + +extern 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 **), + void (*ref_obj_release) + (struct ttm_base_object *, + enum ttm_ref_type ref_type)); + +static inline enum ttm_object_type +ttm_base_object_type(struct ttm_base_object *base) +{ + return (base->object_type == ttm_prime_type) ? + container_of(base, struct ttm_prime_object, base)->real_type : + base->object_type; +} +extern int ttm_prime_fd_to_handle(struct ttm_object_file *tfile, + int fd, u32 *handle); +extern int ttm_prime_handle_to_fd(struct ttm_object_file *tfile, + uint32_t handle, uint32_t flags, + int *prime_fd); + +#define ttm_prime_object_kfree(__obj, __prime) \ + kfree_rcu(__obj, __prime.base.rhead) #endif