[PATCH 1/4] [RFC]drm: add syncobj timeline support v6

Christian König christian.koenig at amd.com
Wed Sep 19 08:07:45 UTC 2018


Am 19.09.2018 um 10:03 schrieb Zhou, David(ChunMing):
>
>> -----Original Message-----
>> From: amd-gfx <amd-gfx-bounces at lists.freedesktop.org> On Behalf Of
>> Christian K?nig
>> Sent: Wednesday, September 19, 2018 3:45 PM
>> To: Zhou, David(ChunMing) <David1.Zhou at amd.com>; Zhou,
>> David(ChunMing) <David1.Zhou at amd.com>; dri-
>> devel at lists.freedesktop.org
>> Cc: Dave Airlie <airlied at redhat.com>; Rakos, Daniel
>> <Daniel.Rakos at amd.com>; Daniel Vetter <daniel at ffwll.ch>; amd-
>> gfx at lists.freedesktop.org
>> Subject: Re: [PATCH 1/4] [RFC]drm: add syncobj timeline support v6
>>
>> Am 19.09.2018 um 09:32 schrieb zhoucm1:
>>>
>>> On 2018年09月19日 15:18, Christian König wrote:
>>>> Am 19.09.2018 um 06:26 schrieb Chunming Zhou:
>>> [snip]
>>>>>            *fence = NULL;
>>>>>            drm_syncobj_add_callback_locked(syncobj, cb, func); @@
>>>>> -164,6 +177,153 @@ void drm_syncobj_remove_callback(struct
>>>>> drm_syncobj *syncobj,
>>>>>        spin_unlock(&syncobj->lock);
>>>>>    }
>>>>>    +static void drm_syncobj_timeline_init(struct drm_syncobj
>>>>> *syncobj)
>>>> We still have _timeline_ in the name here.
>>> the func is relevant to timeline members, or which name is proper?
>> Yeah, but we now use the timeline implementation for the individual syncobj
>> as well.
>>
>> Not a big issue, but I would just name it
>> drm_syncobj_init()/drm_syncobj_fini.
> There is already drm_syncobj_init/fini in drm_syncboj.c , any other name can be suggested?

Hui what? I actually checked that there is no 
drm_syncobj_init()/drm_syncobj_fini() in drm_syncobj.c before suggesting 
it. Am I missing something?

>>>>> +{
>>>>> +    spin_lock(&syncobj->lock);
>>>>> +    syncobj->timeline_context = dma_fence_context_alloc(1);
>>> [snip]
>>>>> +}
>>>>> +
>>>>> +int drm_syncobj_lookup_fence(struct drm_syncobj *syncobj, u64
>>>>> +point,
>>>>> +               struct dma_fence **fence) {
>>>>> +
>>>>> +    return drm_syncobj_search_fence(syncobj, point,
>>>>> +                    DRM_SYNCOBJ_WAIT_FLAGS_WAIT_FOR_SUBMIT,
>>>> I still have a bad feeling setting that flag as default cause it
>>>> might change the behavior for the UAPI.
>>>>
>>>> Maybe export drm_syncobj_search_fence directly? E.g. with the flags
>>>> parameter.
>>> previous v5 indeed do this, you let me wrap it, need change back?
>> No, the problem is that drm_syncobj_find_fence() is still using
>> drm_syncobj_lookup_fence() which sets the flag instead of
>> drm_syncobj_search_fence() without the flag.
>>
>> That changes the UAPI behavior because previously we would have returned
>> an error code and now we block for a fence to appear.
>>
>> So I think the right solution would be to add the flags parameter to
>> drm_syncobj_find_fence() and let the driver decide if we need to block or
>> get -ENOENT.
> Got your means,
> Exporting flag in func is easy,
>   but driver doesn't pass flag, which flag is proper by default? We still need to give a default flag in patch, don't we?

Well proper solution is to keep the old behavior as it is for now.

So passing 0 as flag by default and making sure we get a -ENOENT in that 
case sounds like the right approach to me.

Adding the DRM_SYNCOBJ_WAIT_FLAGS_WAIT_FOR_SUBMIT flag can happen when 
the driver starts to provide a proper point as well.

Christian.

>
> Thanks,
> David Zhou
>
>> Regards,
>> Christian.
>>
>>> Regards,
>>> David Zhou
>>>> Regards,
>>>> Christian.
>>>>
>>>>> +                    fence);
>>>>> +}
>>>>> +EXPORT_SYMBOL(drm_syncobj_lookup_fence);
>>>>> +
>>>>>    /**
>>>>>     * drm_syncobj_find_fence - lookup and reference the fence in a
>>>>> sync object
>>>>>     * @file_private: drm file private pointer @@ -228,7 +443,7 @@
>>>>> static int drm_syncobj_assign_null_handle(struct
>>>>> drm_syncobj *syncobj)
>>>>>     * @fence: out parameter for the fence
>>>>>     *
>>>>>     * This is just a convenience function that combines
>>>>> drm_syncobj_find() and
>>>>> - * drm_syncobj_fence_get().
>>>>> + * drm_syncobj_lookup_fence().
>>>>>     *
>>>>>     * Returns 0 on success or a negative error value on failure. On
>>>>> success @fence
>>>>>     * contains a reference to the fence, which must be released by
>>>>> calling @@ -236,18 +451,11 @@ static int
>>>>> drm_syncobj_assign_null_handle(struct drm_syncobj *syncobj)
>>>>>     */
>>>>>    int drm_syncobj_find_fence(struct drm_file *file_private,
>>>>>                   u32 handle, u64 point,
>>>>> -               struct dma_fence **fence) -{
>>>>> +               struct dma_fence **fence) {
>>>>>        struct drm_syncobj *syncobj = drm_syncobj_find(file_private,
>>>>> handle);
>>>>> -    int ret = 0;
>>>>> -
>>>>> -    if (!syncobj)
>>>>> -        return -ENOENT;
>>>>> +    int ret;
>>>>>    -    *fence = drm_syncobj_fence_get(syncobj);
>>>>> -    if (!*fence) {
>>>>> -        ret = -EINVAL;
>>>>> -    }
>>>>> +    ret = drm_syncobj_lookup_fence(syncobj, point, fence);
>>>>>        drm_syncobj_put(syncobj);
>>>>>        return ret;
>>>>>    }
>>>>> @@ -264,7 +472,7 @@ void drm_syncobj_free(struct kref *kref)
>>>>>        struct drm_syncobj *syncobj = container_of(kref,
>>>>>                               struct drm_syncobj,
>>>>>                               refcount);
>>>>> -    drm_syncobj_replace_fence(syncobj, 0, NULL);
>>>>> +    drm_syncobj_timeline_fini(syncobj);
>>>>>        kfree(syncobj);
>>>>>    }
>>>>>    EXPORT_SYMBOL(drm_syncobj_free);
>>>>> @@ -294,6 +502,11 @@ int drm_syncobj_create(struct drm_syncobj
>>>>> **out_syncobj, uint32_t flags,
>>>>>        kref_init(&syncobj->refcount);
>>>>>        INIT_LIST_HEAD(&syncobj->cb_list);
>>>>>        spin_lock_init(&syncobj->lock);
>>>>> +    if (flags & DRM_SYNCOBJ_CREATE_TYPE_TIMELINE)
>>>>> +        syncobj->type = DRM_SYNCOBJ_TYPE_TIMELINE;
>>>>> +    else
>>>>> +        syncobj->type = DRM_SYNCOBJ_TYPE_INDIVIDUAL;
>>>>> +    drm_syncobj_timeline_init(syncobj);
>>>>>          if (flags & DRM_SYNCOBJ_CREATE_SIGNALED) {
>>>>>            ret = drm_syncobj_assign_null_handle(syncobj);
>>>>> @@ -576,7 +789,8 @@ drm_syncobj_create_ioctl(struct drm_device
>> *dev,
>>>>> void *data,
>>>>>            return -ENODEV;
>>>>>          /* no valid flags yet */
>>>>> -    if (args->flags & ~DRM_SYNCOBJ_CREATE_SIGNALED)
>>>>> +    if (args->flags & ~(DRM_SYNCOBJ_CREATE_SIGNALED |
>>>>> +                DRM_SYNCOBJ_CREATE_TYPE_TIMELINE))
>>>>>            return -EINVAL;
>>>>>          return drm_syncobj_create_as_handle(file_private,
>>>>> @@ -669,9 +883,8 @@ static void syncobj_wait_syncobj_func(struct
>>>>> drm_syncobj *syncobj,
>>>>>        struct syncobj_wait_entry *wait =
>>>>>            container_of(cb, struct syncobj_wait_entry, syncobj_cb);
>>>>>    -    /* This happens inside the syncobj lock */
>>>>> -    wait->fence =
>>>>> dma_fence_get(rcu_dereference_protected(syncobj->fence,
>>>>> - lockdep_is_held(&syncobj->lock)));
>>>>> +    drm_syncobj_search_fence(syncobj, 0, 0, &wait->fence);
>>>>> +
>>>>>        wake_up_process(wait->task);
>>>>>    }
>>>>>    @@ -698,7 +911,8 @@ static signed long
>>>>> drm_syncobj_array_wait_timeout(struct drm_syncobj **syncobjs,
>>>>>        signaled_count = 0;
>>>>>        for (i = 0; i < count; ++i) {
>>>>>            entries[i].task = current;
>>>>> -        entries[i].fence = drm_syncobj_fence_get(syncobjs[i]);
>>>>> +        ret = drm_syncobj_search_fence(syncobjs[i], 0, 0,
>>>>> +                           &entries[i].fence);
>>>>>            if (!entries[i].fence) {
>>>>>                if (flags & DRM_SYNCOBJ_WAIT_FLAGS_WAIT_FOR_SUBMIT) {
>>>>>                    continue;
>>>>> @@ -970,12 +1184,19 @@ drm_syncobj_reset_ioctl(struct drm_device
>>>>> *dev, void *data,
>>>>>        if (ret < 0)
>>>>>            return ret;
>>>>>    -    for (i = 0; i < args->count_handles; i++)
>>>>> -        drm_syncobj_replace_fence(syncobjs[i], 0, NULL);
>>>>> -
>>>>> +    for (i = 0; i < args->count_handles; i++) {
>>>>> +        if (syncobjs[i]->type == DRM_SYNCOBJ_TYPE_TIMELINE) {
>>>>> +            DRM_ERROR("timeline syncobj cannot reset!\n");
>>>>> +            ret = -EINVAL;
>>>>> +            goto out;
>>>>> +        }
>>>>> +        drm_syncobj_timeline_fini(syncobjs[i]);
>>>>> +        drm_syncobj_timeline_init(syncobjs[i]);
>>>>> +    }
>>>>> +out:
>>>>>        drm_syncobj_array_free(syncobjs, args->count_handles);
>>>>>    -    return 0;
>>>>> +    return ret;
>>>>>    }
>>>>>      int
>>>>> diff --git a/drivers/gpu/drm/i915/i915_gem_execbuffer.c
>>>>> b/drivers/gpu/drm/i915/i915_gem_execbuffer.c
>>>>> index 0a8d2d64f380..a040fa3281df 100644
>>>>> --- a/drivers/gpu/drm/i915/i915_gem_execbuffer.c
>>>>> +++ b/drivers/gpu/drm/i915/i915_gem_execbuffer.c
>>>>> @@ -2137,7 +2137,7 @@ await_fence_array(struct i915_execbuffer *eb,
>>>>>            if (!(flags & I915_EXEC_FENCE_WAIT))
>>>>>                continue;
>>>>>    -        fence = drm_syncobj_fence_get(syncobj);
>>>>> +        drm_syncobj_lookup_fence(syncobj, 0, &fence);
>>>>>            if (!fence)
>>>>>                return -EINVAL;
>>>>>    diff --git a/include/drm/drm_syncobj.h b/include/drm/drm_syncobj.h
>>>>> index 425432b85a87..6dac479fedfe 100644
>>>>> --- a/include/drm/drm_syncobj.h
>>>>> +++ b/include/drm/drm_syncobj.h
>>>>> @@ -30,6 +30,11 @@
>>>>>      struct drm_syncobj_cb;
>>>>>    +enum drm_syncobj_type {
>>>>> +    DRM_SYNCOBJ_TYPE_INDIVIDUAL,
>>>>> +    DRM_SYNCOBJ_TYPE_TIMELINE
>>>>> +};
>>>>> +
>>>>>    /**
>>>>>     * struct drm_syncobj - sync object.
>>>>>     *
>>>>> @@ -41,19 +46,36 @@ struct drm_syncobj {
>>>>>         */
>>>>>        struct kref refcount;
>>>>>        /**
>>>>> -     * @fence:
>>>>> -     * NULL or a pointer to the fence bound to this object.
>>>>> -     *
>>>>> -     * This field should not be used directly. Use
>>>>> drm_syncobj_fence_get()
>>>>> -     * and drm_syncobj_replace_fence() instead.
>>>>> +     * @type: indicate syncobj type
>>>>> +     */
>>>>> +    enum drm_syncobj_type type;
>>>>> +    /**
>>>>> +     * @wq: wait signal operation work queue
>>>>> +     */
>>>>> +    wait_queue_head_t    wq;
>>>>> +    /**
>>>>> +     * @timeline_context: fence context used by timeline
>>>>>         */
>>>>> -    struct dma_fence __rcu *fence;
>>>>> +    u64 timeline_context;
>>>>>        /**
>>>>> -     * @cb_list: List of callbacks to call when the &fence gets
>>>>> replaced.
>>>>> +     * @timeline: syncobj timeline value, which indicates point is
>>>>> signaled.
>>>>>         */
>>>>> +    u64 timeline;
>>>>> +    /**
>>>>> +     * @signal_point: which indicates the latest signaler point.
>>>>> +     */
>>>>> +    u64 signal_point;
>>>>> +    /**
>>>>> +     * @signal_pt_list: signaler point list.
>>>>> +     */
>>>>> +    struct list_head signal_pt_list;
>>>>> +
>>>>> +    /**
>>>>> +         * @cb_list: List of callbacks to call when the &fence gets
>>>>> replaced.
>>>>> +         */
>>>>>        struct list_head cb_list;
>>>>>        /**
>>>>> -     * @lock: Protects &cb_list and write-locks &fence.
>>>>> +     * @lock: Protects syncobj list and write-locks &fence.
>>>>>         */
>>>>>        spinlock_t lock;
>>>>>        /**
>>>>> @@ -68,7 +90,7 @@ typedef void (*drm_syncobj_func_t)(struct
>>>>> drm_syncobj *syncobj,
>>>>>    /**
>>>>>     * struct drm_syncobj_cb - callback for drm_syncobj_add_callback
>>>>>     * @node: used by drm_syncob_add_callback to append this struct to
>>>>> - *      &drm_syncobj.cb_list
>>>>> + *       &drm_syncobj.cb_list
>>>>>     * @func: drm_syncobj_func_t to call
>>>>>     *
>>>>>     * This struct will be initialized by drm_syncobj_add_callback,
>>>>> additional @@ -106,29 +128,6 @@ drm_syncobj_put(struct drm_syncobj
>>>>> *obj)
>>>>>        kref_put(&obj->refcount, drm_syncobj_free);
>>>>>    }
>>>>>    -/**
>>>>> - * drm_syncobj_fence_get - get a reference to a fence in a sync
>>>>> object
>>>>> - * @syncobj: sync object.
>>>>> - *
>>>>> - * This acquires additional reference to &drm_syncobj.fence
>>>>> contained in @obj,
>>>>> - * if not NULL. It is illegal to call this without already holding
>>>>> a reference.
>>>>> - * No locks required.
>>>>> - *
>>>>> - * Returns:
>>>>> - * Either the fence of @obj or NULL if there's none.
>>>>> - */
>>>>> -static inline struct dma_fence *
>>>>> -drm_syncobj_fence_get(struct drm_syncobj *syncobj) -{
>>>>> -    struct dma_fence *fence;
>>>>> -
>>>>> -    rcu_read_lock();
>>>>> -    fence = dma_fence_get_rcu_safe(&syncobj->fence);
>>>>> -    rcu_read_unlock();
>>>>> -
>>>>> -    return fence;
>>>>> -}
>>>>> -
>>>>>    struct drm_syncobj *drm_syncobj_find(struct drm_file
>>>>> *file_private,
>>>>>                         u32 handle);
>>>>>    void drm_syncobj_replace_fence(struct drm_syncobj *syncobj, u64
>>>>> point, @@ -142,5 +141,7 @@ int drm_syncobj_create(struct
>> drm_syncobj
>>>>> **out_syncobj, uint32_t flags,
>>>>>    int drm_syncobj_get_handle(struct drm_file *file_private,
>>>>>                   struct drm_syncobj *syncobj, u32 *handle);
>>>>>    int drm_syncobj_get_fd(struct drm_syncobj *syncobj, int *p_fd);
>>>>> +int drm_syncobj_lookup_fence(struct drm_syncobj *syncobj, u64
>>>>> +point,
>>>>> +                 struct dma_fence **fence);
>>>>>      #endif
>>>>> diff --git a/include/uapi/drm/drm.h b/include/uapi/drm/drm.h index
>>>>> 300f336633f2..cebdb2541eb7 100644
>>>>> --- a/include/uapi/drm/drm.h
>>>>> +++ b/include/uapi/drm/drm.h
>>>>> @@ -717,6 +717,7 @@ struct drm_prime_handle {
>>>>>    struct drm_syncobj_create {
>>>>>        __u32 handle;
>>>>>    #define DRM_SYNCOBJ_CREATE_SIGNALED (1 << 0)
>>>>> +#define DRM_SYNCOBJ_CREATE_TYPE_TIMELINE (1 << 1)
>>>>>        __u32 flags;
>>>>>    };
>> _______________________________________________
>> amd-gfx mailing list
>> amd-gfx at lists.freedesktop.org
>> https://lists.freedesktop.org/mailman/listinfo/amd-gfx



More information about the amd-gfx mailing list