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drm/ttm: Add a minimal prime implementation for ttm base objects

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Signed-off-by: Thomas Hellstrom <thellstrom@vmware.com>
Reviewed-by: Jakob Bornecrantz <jakob@vmware.com>
This commit is contained in:
Thomas Hellstrom 2013-11-13 01:48:31 -08:00
parent ac49251b6b
commit 65981f7681
2 changed files with 307 additions and 8 deletions
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254
drivers/gpu/drm/ttm/ttm_object.c
View File

@ -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);

61
include/drm/ttm/ttm_object.h
View File

@ -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