Re: [PATCH v2 3/9] drm/amdgpu: add new IOCTL for usermode queue

[Shashank Sharma <shashank.sharma@xxxxxxx>]

Hey Christian,

On 16/02/2023 08:23, Christian König wrote:
> Am 15.02.23 um 19:43 schrieb Shashank Sharma:
> > From: Shashank Sharma <contactshashanksharma@xxxxxxxxx>
> >
> > This patch adds:
> > - A new IOCTL function to create and destroy
> > - A new structure to keep all the user queue data in one place.
> > - A function to generate unique index for the queue.
> >
> > V1: Worked on review comments from RFC patch series:
> >    - Alex: Keep a list of queues, instead of single queue per process.
> >    - Christian: Use the queue manager instead of global ptrs,
> >             Don't keep the queue structure in amdgpu_ctx
> >
> > V2: Worked on review comments:
> >   - Christian:
> >     - Formatting of text
> >     - There is no need for queuing of userqueues, with idr in place
> >   - Alex:
> >     - Remove use_doorbell, its unnecessary
> >     - Reuse amdgpu_mqd_props for saving mqd fields
> >
> >   - Code formatting and re-arrangement
> >
> > Cc: Alex Deucher <alexander.deucher@xxxxxxx>
> > Cc: Christian Koenig <christian.koenig@xxxxxxx>
> > Signed-off-by: Shashank Sharma <contactshashanksharma@xxxxxxxxx>
> > ---
> >   drivers/gpu/drm/amd/amdgpu/amdgpu_drv.c       |   1 +
> >   drivers/gpu/drm/amd/amdgpu/amdgpu_userqueue.c | 114 ++++++++++++++++++
> >   .../gpu/drm/amd/include/amdgpu_userqueue.h    |   2 +
> >   3 files changed, 117 insertions(+)
> >
> > diff --git a/drivers/gpu/drm/amd/amdgpu/amdgpu_drv.c 
> > b/drivers/gpu/drm/amd/amdgpu/amdgpu_drv.c
> > index 2d6bcfd727c8..229976a2d0e7 100644
> > --- a/drivers/gpu/drm/amd/amdgpu/amdgpu_drv.c
> > +++ b/drivers/gpu/drm/amd/amdgpu/amdgpu_drv.c
> > @@ -2749,6 +2749,7 @@ const struct drm_ioctl_desc amdgpu_ioctls_kms[] 
> > = {
> >       DRM_IOCTL_DEF_DRV(AMDGPU_GEM_VA, amdgpu_gem_va_ioctl, 
> > DRM_AUTH|DRM_RENDER_ALLOW),
> >       DRM_IOCTL_DEF_DRV(AMDGPU_GEM_OP, amdgpu_gem_op_ioctl, 
> > DRM_AUTH|DRM_RENDER_ALLOW),
> >       DRM_IOCTL_DEF_DRV(AMDGPU_GEM_USERPTR, amdgpu_gem_userptr_ioctl, 
> > DRM_AUTH|DRM_RENDER_ALLOW),
> > +    DRM_IOCTL_DEF_DRV(AMDGPU_USERQ, amdgpu_userq_ioctl, 
> > DRM_AUTH|DRM_RENDER_ALLOW),
> >   };
> >     static const struct drm_driver amdgpu_kms_driver = {
> > diff --git a/drivers/gpu/drm/amd/amdgpu/amdgpu_userqueue.c 
> > b/drivers/gpu/drm/amd/amdgpu/amdgpu_userqueue.c
> > index 13e1eebc1cb6..ecf31d86f3de 100644
> > --- a/drivers/gpu/drm/amd/amdgpu/amdgpu_userqueue.c
> > +++ b/drivers/gpu/drm/amd/amdgpu/amdgpu_userqueue.c
> > @@ -22,6 +22,120 @@
> >    */
> >     #include "amdgpu.h"
> > +#include "amdgpu_vm.h"
> > +#include "amdgpu_userqueue.h"
> > +
> > +static inline int
> > +amdgpu_userqueue_index(struct amdgpu_userq_mgr *uq_mgr, struct 
> > amdgpu_usermode_queue *queue)
> > +{
> > +    return idr_alloc(&uq_mgr->userq_idr, queue, 1, AMDGPU_MAX_USERQ, 
> > GFP_KERNEL);
> > +}
> > +
> > +static inline void
> > +amdgpu_userqueue_free_index(struct amdgpu_userq_mgr *uq_mgr, int 
> > queue_id)
> > +{
> > +    idr_remove(&uq_mgr->userq_idr, queue_id);
> > +}
> > +
> > +static struct amdgpu_usermode_queue *
> > +amdgpu_userqueue_find(struct amdgpu_userq_mgr *uq_mgr, int qid)
> > +{
> > +    return idr_find(&uq_mgr->userq_idr, qid);
> > +}
> > +
> > +static int amdgpu_userqueue_create(struct drm_file *filp, union 
> > drm_amdgpu_userq *args)
> > +{
> > +    struct amdgpu_usermode_queue *queue;
> > +    struct amdgpu_fpriv *fpriv = filp->driver_priv;
> > +    struct amdgpu_userq_mgr *uq_mgr = &fpriv->userq_mgr;
> > +    struct drm_amdgpu_userq_mqd *mqd_in = &args->in.mqd;
> > +    int r;
> > +
> > +    /* Do we have support userqueues for this IP ? */
> > +    if (!uq_mgr->userq_funcs[mqd_in->ip_type]) {
> > +        DRM_ERROR("GFX User queues not supported for this IP: %d\n", 
> > mqd_in->ip_type);
> > +        return -EINVAL;
> > +    }
> > +
> > +    queue = kzalloc(sizeof(struct amdgpu_usermode_queue), GFP_KERNEL);
> > +    if (!queue) {
> > +        DRM_ERROR("Failed to allocate memory for queue\n");
> > +        return -ENOMEM;
> > +    }
> > +
> > +    mutex_lock(&uq_mgr->userq_mutex);
> > +    queue->userq_prop.wptr_gpu_addr = mqd_in->wptr_va;
> > +    queue->userq_prop.rptr_gpu_addr = mqd_in->rptr_va;
> > +    queue->userq_prop.queue_size = mqd_in->queue_size;
> > +    queue->userq_prop.hqd_base_gpu_addr = mqd_in->queue_va;
> > +    queue->userq_prop.queue_size = mqd_in->queue_size;
> > +
> > +    queue->doorbell_handle = mqd_in->doorbell_handle;
> > +    queue->queue_type = mqd_in->ip_type;
> > +    queue->flags = mqd_in->flags;
> > +    queue->vm = &fpriv->vm;
> > +    queue->shadow_ctx_gpu_addr = mqd_in->shadow_va;
>
> > +    queue->queue_id = amdgpu_userqueue_index(uq_mgr, queue);
> > +    if (queue->queue_id < 0) {
> > +        DRM_ERROR("Failed to allocate a queue id\n");
> > +        r = queue->queue_id;
> > +        goto free_queue;
> > +    }
>
> Don't keep the assigned id inside the queue structure. This is only 
> used as handle between userspace and kernel and not useful inside the 
> kernel otherwise.
>
> This prevents people from using it in hw communication.

Noted,

- Shashank

> Apart from that this looks good to me,
> Christian.
>
> > +
> > +    args->out.queue_id = queue->queue_id;
> > +    args->out.flags = 0;
> > +    mutex_unlock(&uq_mgr->userq_mutex);
> > +    return 0;
> > +
> > +free_queue:
> > +    mutex_unlock(&uq_mgr->userq_mutex);
> > +    kfree(queue);
> > +    return r;
> > +}
> > +
> > +static void amdgpu_userqueue_destroy(struct drm_file *filp, int 
> > queue_id)
> > +{
> > +    struct amdgpu_fpriv *fpriv = filp->driver_priv;
> > +    struct amdgpu_userq_mgr *uq_mgr = &fpriv->userq_mgr;
> > +    struct amdgpu_usermode_queue *queue;
> > +
> > +    queue = amdgpu_userqueue_find(uq_mgr, queue_id);
> > +    if (!queue) {
> > +        DRM_DEBUG_DRIVER("Invalid queue id to destroy\n");
> > +        return;
> > +    }
> > +
> > +    mutex_lock(&uq_mgr->userq_mutex);
> > +    amdgpu_userqueue_free_index(uq_mgr, queue->queue_id);
> > +    mutex_unlock(&uq_mgr->userq_mutex);
> > +    kfree(queue);
> > +}
> > +
> > +int amdgpu_userq_ioctl(struct drm_device *dev, void *data,
> > +               struct drm_file *filp)
> > +{
> > +    union drm_amdgpu_userq *args = data;
> > +    int r = 0;
> > +
> > +    switch (args->in.op) {
> > +    case AMDGPU_USERQ_OP_CREATE:
> > +        r = amdgpu_userqueue_create(filp, args);
> > +        if (r)
> > +            DRM_ERROR("Failed to create usermode queue\n");
> > +        break;
> > +
> > +    case AMDGPU_USERQ_OP_FREE:
> > +        amdgpu_userqueue_destroy(filp, args->in.queue_id);
> > +        break;
> > +
> > +    default:
> > +        DRM_ERROR("Invalid user queue op specified: %d\n", 
> > args->in.op);
> > +        return -EINVAL;
> > +    }
> > +
> > +    return r;
> > +}
> > +
> >     int amdgpu_userq_mgr_init(struct amdgpu_userq_mgr *userq_mgr, 
> > struct amdgpu_device *adev)
> >   {
> > diff --git a/drivers/gpu/drm/amd/include/amdgpu_userqueue.h 
> > b/drivers/gpu/drm/amd/include/amdgpu_userqueue.h
> > index 7eeb8c9e6575..7625a862b1fc 100644
> > --- a/drivers/gpu/drm/amd/include/amdgpu_userqueue.h
> > +++ b/drivers/gpu/drm/amd/include/amdgpu_userqueue.h
> > @@ -42,6 +42,8 @@ struct amdgpu_userq_funcs {
> >       void (*mqd_destroy)(struct amdgpu_userq_mgr *, struct 
> > amdgpu_usermode_queue *);
> >   };
> >   +int amdgpu_userq_ioctl(struct drm_device *dev, void *data, struct 
> > drm_file *filp);
> > +
> >   int amdgpu_userq_mgr_init(struct amdgpu_userq_mgr *userq_mgr, 
> > struct amdgpu_device *adev);
> >     void amdgpu_userq_mgr_fini(struct amdgpu_userq_mgr *userq_mgr);