[Date Prev][Date Next][Thread Prev][Thread Next][Date Index][Thread Index]

Re: [Xen-devel] [PATCH 9/9] drm/xen-front: Implement communication with backend



On Wed, Feb 21, 2018 at 10:03:42AM +0200, Oleksandr Andrushchenko wrote:
> From: Oleksandr Andrushchenko <oleksandr_andrushchenko@xxxxxxxx>
> 
> Handle communication with the backend:
>  - send requests and wait for the responses according
>    to the displif protocol
>  - serialize access to the communication channel
>  - time-out used for backend communication is set to 3000 ms
>  - manage display buffers shared with the backend
> 
> Signed-off-by: Oleksandr Andrushchenko <oleksandr_andrushchenko@xxxxxxxx>

After the demidlayering it probably makes sense to merge this with the
overall kms/basic-drm-driver patch. Up to you really.
-Daniel
> ---
>  drivers/gpu/drm/xen/xen_drm_front.c | 327 
> +++++++++++++++++++++++++++++++++++-
>  drivers/gpu/drm/xen/xen_drm_front.h |   5 +
>  2 files changed, 327 insertions(+), 5 deletions(-)
> 
> diff --git a/drivers/gpu/drm/xen/xen_drm_front.c 
> b/drivers/gpu/drm/xen/xen_drm_front.c
> index 8de88e359d5e..5ad546231d30 100644
> --- a/drivers/gpu/drm/xen/xen_drm_front.c
> +++ b/drivers/gpu/drm/xen/xen_drm_front.c
> @@ -31,12 +31,146 @@
>  #include "xen_drm_front_evtchnl.h"
>  #include "xen_drm_front_shbuf.h"
>  
> +/* timeout in ms to wait for backend to respond */
> +#define VDRM_WAIT_BACK_MS    3000
> +
> +struct xen_drm_front_dbuf {
> +     struct list_head list;
> +     uint64_t dbuf_cookie;
> +     uint64_t fb_cookie;
> +     struct xen_drm_front_shbuf *shbuf;
> +};
> +
> +static int dbuf_add_to_list(struct xen_drm_front_info *front_info,
> +             struct xen_drm_front_shbuf *shbuf, uint64_t dbuf_cookie)
> +{
> +     struct xen_drm_front_dbuf *dbuf;
> +
> +     dbuf = kzalloc(sizeof(*dbuf), GFP_KERNEL);
> +     if (!dbuf)
> +             return -ENOMEM;
> +
> +     dbuf->dbuf_cookie = dbuf_cookie;
> +     dbuf->shbuf = shbuf;
> +     list_add(&dbuf->list, &front_info->dbuf_list);
> +     return 0;
> +}
> +
> +static struct xen_drm_front_dbuf *dbuf_get(struct list_head *dbuf_list,
> +             uint64_t dbuf_cookie)
> +{
> +     struct xen_drm_front_dbuf *buf, *q;
> +
> +     list_for_each_entry_safe(buf, q, dbuf_list, list)
> +             if (buf->dbuf_cookie == dbuf_cookie)
> +                     return buf;
> +
> +     return NULL;
> +}
> +
> +static void dbuf_flush_fb(struct list_head *dbuf_list, uint64_t fb_cookie)
> +{
> +     struct xen_drm_front_dbuf *buf, *q;
> +
> +     list_for_each_entry_safe(buf, q, dbuf_list, list)
> +             if (buf->fb_cookie == fb_cookie)
> +                     xen_drm_front_shbuf_flush(buf->shbuf);
> +}
> +
> +static void dbuf_free(struct list_head *dbuf_list, uint64_t dbuf_cookie)
> +{
> +     struct xen_drm_front_dbuf *buf, *q;
> +
> +     list_for_each_entry_safe(buf, q, dbuf_list, list)
> +             if (buf->dbuf_cookie == dbuf_cookie) {
> +                     list_del(&buf->list);
> +                     xen_drm_front_shbuf_unmap(buf->shbuf);
> +                     xen_drm_front_shbuf_free(buf->shbuf);
> +                     kfree(buf);
> +                     break;
> +             }
> +}
> +
> +static void dbuf_free_all(struct list_head *dbuf_list)
> +{
> +     struct xen_drm_front_dbuf *buf, *q;
> +
> +     list_for_each_entry_safe(buf, q, dbuf_list, list) {
> +             list_del(&buf->list);
> +             xen_drm_front_shbuf_unmap(buf->shbuf);
> +             xen_drm_front_shbuf_free(buf->shbuf);
> +             kfree(buf);
> +     }
> +}
> +
> +static struct xendispl_req *be_prepare_req(
> +             struct xen_drm_front_evtchnl *evtchnl, uint8_t operation)
> +{
> +     struct xendispl_req *req;
> +
> +     req = RING_GET_REQUEST(&evtchnl->u.req.ring,
> +                     evtchnl->u.req.ring.req_prod_pvt);
> +     req->operation = operation;
> +     req->id = evtchnl->evt_next_id++;
> +     evtchnl->evt_id = req->id;
> +     return req;
> +}
> +
> +static int be_stream_do_io(struct xen_drm_front_evtchnl *evtchnl,
> +             struct xendispl_req *req)
> +{
> +     reinit_completion(&evtchnl->u.req.completion);
> +     if (unlikely(evtchnl->state != EVTCHNL_STATE_CONNECTED))
> +             return -EIO;
> +
> +     xen_drm_front_evtchnl_flush(evtchnl);
> +     return 0;
> +}
> +
> +static int be_stream_wait_io(struct xen_drm_front_evtchnl *evtchnl)
> +{
> +     if (wait_for_completion_timeout(&evtchnl->u.req.completion,
> +                     msecs_to_jiffies(VDRM_WAIT_BACK_MS)) <= 0)
> +             return -ETIMEDOUT;
> +
> +     return evtchnl->u.req.resp_status;
> +}
> +
>  static int be_mode_set(struct xen_drm_front_drm_pipeline *pipeline, uint32_t 
> x,
>               uint32_t y, uint32_t width, uint32_t height, uint32_t bpp,
>               uint64_t fb_cookie)
>  
>  {
> -     return 0;
> +     struct xen_drm_front_evtchnl *evtchnl;
> +     struct xen_drm_front_info *front_info;
> +     struct xendispl_req *req;
> +     unsigned long flags;
> +     int ret;
> +
> +     front_info = pipeline->drm_info->front_info;
> +     evtchnl = &front_info->evt_pairs[pipeline->index].req;
> +     if (unlikely(!evtchnl))
> +             return -EIO;
> +
> +     mutex_lock(&front_info->req_io_lock);
> +
> +     spin_lock_irqsave(&front_info->io_lock, flags);
> +     req = be_prepare_req(evtchnl, XENDISPL_OP_SET_CONFIG);
> +     req->op.set_config.x = x;
> +     req->op.set_config.y = y;
> +     req->op.set_config.width = width;
> +     req->op.set_config.height = height;
> +     req->op.set_config.bpp = bpp;
> +     req->op.set_config.fb_cookie = fb_cookie;
> +
> +     ret = be_stream_do_io(evtchnl, req);
> +     spin_unlock_irqrestore(&front_info->io_lock, flags);
> +
> +     if (ret == 0)
> +             ret = be_stream_wait_io(evtchnl);
> +
> +     mutex_unlock(&front_info->req_io_lock);
> +     return ret;
>  }
>  
>  static int be_dbuf_create_int(struct xen_drm_front_info *front_info,
> @@ -44,7 +178,69 @@ static int be_dbuf_create_int(struct xen_drm_front_info 
> *front_info,
>               uint32_t bpp, uint64_t size, struct page **pages,
>               struct sg_table *sgt)
>  {
> +     struct xen_drm_front_evtchnl *evtchnl;
> +     struct xen_drm_front_shbuf *shbuf;
> +     struct xendispl_req *req;
> +     struct xen_drm_front_shbuf_cfg buf_cfg;
> +     unsigned long flags;
> +     int ret;
> +
> +     evtchnl = &front_info->evt_pairs[GENERIC_OP_EVT_CHNL].req;
> +     if (unlikely(!evtchnl))
> +             return -EIO;
> +
> +     memset(&buf_cfg, 0, sizeof(buf_cfg));
> +     buf_cfg.xb_dev = front_info->xb_dev;
> +     buf_cfg.pages = pages;
> +     buf_cfg.size = size;
> +     buf_cfg.sgt = sgt;
> +     buf_cfg.be_alloc = front_info->cfg.be_alloc;
> +
> +     shbuf = xen_drm_front_shbuf_alloc(&buf_cfg);
> +     if (!shbuf)
> +             return -ENOMEM;
> +
> +     ret = dbuf_add_to_list(front_info, shbuf, dbuf_cookie);
> +     if (ret < 0) {
> +             xen_drm_front_shbuf_free(shbuf);
> +             return ret;
> +     }
> +
> +     mutex_lock(&front_info->req_io_lock);
> +
> +     spin_lock_irqsave(&front_info->io_lock, flags);
> +     req = be_prepare_req(evtchnl, XENDISPL_OP_DBUF_CREATE);
> +     req->op.dbuf_create.gref_directory =
> +                     xen_drm_front_shbuf_get_dir_start(shbuf);
> +     req->op.dbuf_create.buffer_sz = size;
> +     req->op.dbuf_create.dbuf_cookie = dbuf_cookie;
> +     req->op.dbuf_create.width = width;
> +     req->op.dbuf_create.height = height;
> +     req->op.dbuf_create.bpp = bpp;
> +     if (buf_cfg.be_alloc)
> +             req->op.dbuf_create.flags |= XENDISPL_DBUF_FLG_REQ_ALLOC;
> +
> +     ret = be_stream_do_io(evtchnl, req);
> +     spin_unlock_irqrestore(&front_info->io_lock, flags);
> +
> +     if (ret < 0)
> +             goto fail;
> +
> +     ret = be_stream_wait_io(evtchnl);
> +     if (ret < 0)
> +             goto fail;
> +
> +     ret = xen_drm_front_shbuf_map(shbuf);
> +     if (ret < 0)
> +             goto fail;
> +
> +     mutex_unlock(&front_info->req_io_lock);
>       return 0;
> +
> +fail:
> +     mutex_unlock(&front_info->req_io_lock);
> +     dbuf_free(&front_info->dbuf_list, dbuf_cookie);
> +     return ret;
>  }
>  
>  static int be_dbuf_create_from_sgt(struct xen_drm_front_info *front_info,
> @@ -66,26 +262,144 @@ static int be_dbuf_create_from_pages(struct 
> xen_drm_front_info *front_info,
>  static int be_dbuf_destroy(struct xen_drm_front_info *front_info,
>               uint64_t dbuf_cookie)
>  {
> -     return 0;
> +     struct xen_drm_front_evtchnl *evtchnl;
> +     struct xendispl_req *req;
> +     unsigned long flags;
> +     bool be_alloc;
> +     int ret;
> +
> +     evtchnl = &front_info->evt_pairs[GENERIC_OP_EVT_CHNL].req;
> +     if (unlikely(!evtchnl))
> +             return -EIO;
> +
> +     be_alloc = front_info->cfg.be_alloc;
> +
> +     /*
> +      * for the backend allocated buffer release references now, so backend
> +      * can free the buffer
> +      */
> +     if (be_alloc)
> +             dbuf_free(&front_info->dbuf_list, dbuf_cookie);
> +
> +     mutex_lock(&front_info->req_io_lock);
> +
> +     spin_lock_irqsave(&front_info->io_lock, flags);
> +     req = be_prepare_req(evtchnl, XENDISPL_OP_DBUF_DESTROY);
> +     req->op.dbuf_destroy.dbuf_cookie = dbuf_cookie;
> +
> +     ret = be_stream_do_io(evtchnl, req);
> +     spin_unlock_irqrestore(&front_info->io_lock, flags);
> +
> +     if (ret == 0)
> +             ret = be_stream_wait_io(evtchnl);
> +
> +     /*
> +      * do this regardless of communication status with the backend:
> +      * if we cannot remove remote resources remove what we can locally
> +      */
> +     if (!be_alloc)
> +             dbuf_free(&front_info->dbuf_list, dbuf_cookie);
> +
> +     mutex_unlock(&front_info->req_io_lock);
> +     return ret;
>  }
>  
>  static int be_fb_attach(struct xen_drm_front_info *front_info,
>               uint64_t dbuf_cookie, uint64_t fb_cookie, uint32_t width,
>               uint32_t height, uint32_t pixel_format)
>  {
> -     return 0;
> +     struct xen_drm_front_evtchnl *evtchnl;
> +     struct xen_drm_front_dbuf *buf;
> +     struct xendispl_req *req;
> +     unsigned long flags;
> +     int ret;
> +
> +     evtchnl = &front_info->evt_pairs[GENERIC_OP_EVT_CHNL].req;
> +     if (unlikely(!evtchnl))
> +             return -EIO;
> +
> +     buf = dbuf_get(&front_info->dbuf_list, dbuf_cookie);
> +     if (!buf)
> +             return -EINVAL;
> +
> +     buf->fb_cookie = fb_cookie;
> +
> +     mutex_lock(&front_info->req_io_lock);
> +
> +     spin_lock_irqsave(&front_info->io_lock, flags);
> +     req = be_prepare_req(evtchnl, XENDISPL_OP_FB_ATTACH);
> +     req->op.fb_attach.dbuf_cookie = dbuf_cookie;
> +     req->op.fb_attach.fb_cookie = fb_cookie;
> +     req->op.fb_attach.width = width;
> +     req->op.fb_attach.height = height;
> +     req->op.fb_attach.pixel_format = pixel_format;
> +
> +     ret = be_stream_do_io(evtchnl, req);
> +     spin_unlock_irqrestore(&front_info->io_lock, flags);
> +
> +     if (ret == 0)
> +             ret = be_stream_wait_io(evtchnl);
> +
> +     mutex_unlock(&front_info->req_io_lock);
> +     return ret;
>  }
>  
>  static int be_fb_detach(struct xen_drm_front_info *front_info,
>               uint64_t fb_cookie)
>  {
> -     return 0;
> +     struct xen_drm_front_evtchnl *evtchnl;
> +     struct xendispl_req *req;
> +     unsigned long flags;
> +     int ret;
> +
> +     evtchnl = &front_info->evt_pairs[GENERIC_OP_EVT_CHNL].req;
> +     if (unlikely(!evtchnl))
> +             return -EIO;
> +
> +     mutex_lock(&front_info->req_io_lock);
> +
> +     spin_lock_irqsave(&front_info->io_lock, flags);
> +     req = be_prepare_req(evtchnl, XENDISPL_OP_FB_DETACH);
> +     req->op.fb_detach.fb_cookie = fb_cookie;
> +
> +     ret = be_stream_do_io(evtchnl, req);
> +     spin_unlock_irqrestore(&front_info->io_lock, flags);
> +
> +     if (ret == 0)
> +             ret = be_stream_wait_io(evtchnl);
> +
> +     mutex_unlock(&front_info->req_io_lock);
> +     return ret;
>  }
>  
>  static int be_page_flip(struct xen_drm_front_info *front_info, int conn_idx,
>               uint64_t fb_cookie)
>  {
> -     return 0;
> +     struct xen_drm_front_evtchnl *evtchnl;
> +     struct xendispl_req *req;
> +     unsigned long flags;
> +     int ret;
> +
> +     if (unlikely(conn_idx >= front_info->num_evt_pairs))
> +             return -EINVAL;
> +
> +     dbuf_flush_fb(&front_info->dbuf_list, fb_cookie);
> +     evtchnl = &front_info->evt_pairs[conn_idx].req;
> +
> +     mutex_lock(&front_info->req_io_lock);
> +
> +     spin_lock_irqsave(&front_info->io_lock, flags);
> +     req = be_prepare_req(evtchnl, XENDISPL_OP_PG_FLIP);
> +     req->op.pg_flip.fb_cookie = fb_cookie;
> +
> +     ret = be_stream_do_io(evtchnl, req);
> +     spin_unlock_irqrestore(&front_info->io_lock, flags);
> +
> +     if (ret == 0)
> +             ret = be_stream_wait_io(evtchnl);
> +
> +     mutex_unlock(&front_info->req_io_lock);
> +     return ret;
>  }
>  
>  static void xen_drm_drv_unload(struct xen_drm_front_info *front_info)
> @@ -183,6 +497,7 @@ static void xen_drv_remove_internal(struct 
> xen_drm_front_info *front_info)
>  {
>       xen_drm_drv_deinit(front_info);
>       xen_drm_front_evtchnl_free_all(front_info);
> +     dbuf_free_all(&front_info->dbuf_list);
>  }
>  
>  static int backend_on_initwait(struct xen_drm_front_info *front_info)
> @@ -310,6 +625,8 @@ static int xen_drv_probe(struct xenbus_device *xb_dev,
>  
>       front_info->xb_dev = xb_dev;
>       spin_lock_init(&front_info->io_lock);
> +     mutex_init(&front_info->req_io_lock);
> +     INIT_LIST_HEAD(&front_info->dbuf_list);
>       front_info->drm_pdrv_registered = false;
>       dev_set_drvdata(&xb_dev->dev, front_info);
>       return xenbus_switch_state(xb_dev, XenbusStateInitialising);
> diff --git a/drivers/gpu/drm/xen/xen_drm_front.h 
> b/drivers/gpu/drm/xen/xen_drm_front.h
> index c6f52c892434..db32d00145d1 100644
> --- a/drivers/gpu/drm/xen/xen_drm_front.h
> +++ b/drivers/gpu/drm/xen/xen_drm_front.h
> @@ -137,6 +137,8 @@ struct xen_drm_front_info {
>       struct xenbus_device *xb_dev;
>       /* to protect data between backend IO code and interrupt handler */
>       spinlock_t io_lock;
> +     /* serializer for backend IO: request/response */
> +     struct mutex req_io_lock;
>       bool drm_pdrv_registered;
>       /* virtual DRM platform device */
>       struct platform_device *drm_pdev;
> @@ -144,6 +146,9 @@ struct xen_drm_front_info {
>       int num_evt_pairs;
>       struct xen_drm_front_evtchnl_pair *evt_pairs;
>       struct xen_drm_front_cfg cfg;
> +
> +     /* display buffers */
> +     struct list_head dbuf_list;
>  };
>  
>  #endif /* __XEN_DRM_FRONT_H_ */
> -- 
> 2.7.4
> 
> _______________________________________________
> dri-devel mailing list
> dri-devel@xxxxxxxxxxxxxxxxxxxxx
> https://lists.freedesktop.org/mailman/listinfo/dri-devel

-- 
Daniel Vetter
Software Engineer, Intel Corporation
http://blog.ffwll.ch

_______________________________________________
Xen-devel mailing list
Xen-devel@xxxxxxxxxxxxxxxxxxxx
https://lists.xenproject.org/mailman/listinfo/xen-devel

 


Rackspace

Lists.xenproject.org is hosted with RackSpace, monitoring our
servers 24x7x365 and backed by RackSpace's Fanatical Support®.