Re: [PATCH 1/3] drm/mediatek: Dynamically allocate CMDQ and use helper functions

["CK Hu (胡俊光)" <ck.hu@mediatek.com>]

Hi, Angelo:

On Fri, 2023-06-23 at 11:49 +0200, AngeloGioacchino Del Regno wrote:
>  	 
> External email : Please do not click links or open attachments until
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>  Instead of stack allocating the cmdq_client and cmdq_handle
> structures
> switch them to pointers, allowing us to migrate this driver to use
> the
> common functions provided by mtk-cmdq-helper.
> In order to do this, it was also necessary to add a `priv` pointer to
> struct cmdq_client, as that's used to pass (in this case) a mtk_crtc
> handle to the ddp_cmdq_cb() mailbox RX callback function.
> 
> Signed-off-by: AngeloGioacchino Del Regno <
> angelogioacchino.delregno@collabora.com>
> ---
>  drivers/gpu/drm/mediatek/mtk_drm_crtc.c | 107 +++++++---------------
> --
>  include/linux/soc/mediatek/mtk-cmdq.h   |   1 +
>  2 files changed, 32 insertions(+), 76 deletions(-)
> 
> diff --git a/drivers/gpu/drm/mediatek/mtk_drm_crtc.c
> b/drivers/gpu/drm/mediatek/mtk_drm_crtc.c
> index 0df62b076f49..b63289ab6787 100644
> --- a/drivers/gpu/drm/mediatek/mtk_drm_crtc.c
> +++ b/drivers/gpu/drm/mediatek/mtk_drm_crtc.c
> @@ -50,8 +50,8 @@ struct mtk_drm_crtc {
>  	bool				pending_async_planes;
>  
>  #if IS_REACHABLE(CONFIG_MTK_CMDQ)
> -	struct cmdq_client		cmdq_client;
> -	struct cmdq_pkt			cmdq_handle;
> +	struct cmdq_client		*cmdq_client;
> +	struct cmdq_pkt			*cmdq_handle;
>  	u32				cmdq_event;
>  	u32				cmdq_vblank_cnt;
>  	wait_queue_head_t		cb_blocking_queue;
> @@ -108,47 +108,6 @@ static void mtk_drm_finish_page_flip(struct
> mtk_drm_crtc *mtk_crtc)
>  	}
>  }
>  
> -#if IS_REACHABLE(CONFIG_MTK_CMDQ)
> -static int mtk_drm_cmdq_pkt_create(struct cmdq_client *client,
> struct cmdq_pkt *pkt,
> -				   size_t size)
> -{
> -	struct device *dev;
> -	dma_addr_t dma_addr;
> -
> -	pkt->va_base = kzalloc(size, GFP_KERNEL);
> -	if (!pkt->va_base) {
> -		kfree(pkt);
> -		return -ENOMEM;
> -	}
> -	pkt->buf_size = size;
> -	pkt->cl = (void *)client;

I have a plan to remove cl in struct cmdq_pkt. But this modification
would make this plan more difficult. So I would pending this patch
until cl is removed from struct cmdq_pkt.

Regards,
CK

> -
> -	dev = client->chan->mbox->dev;
> -	dma_addr = dma_map_single(dev, pkt->va_base, pkt->buf_size,
> -				  DMA_TO_DEVICE);
> -	if (dma_mapping_error(dev, dma_addr)) {
> -		dev_err(dev, "dma map failed, size=%u\n",
> (u32)(u64)size);
> -		kfree(pkt->va_base);
> -		kfree(pkt);
> -		return -ENOMEM;
> -	}
> -
> -	pkt->pa_base = dma_addr;
> -
> -	return 0;
> -}
> -
> -static void mtk_drm_cmdq_pkt_destroy(struct cmdq_pkt *pkt)
> -{
> -	struct cmdq_client *client = (struct cmdq_client *)pkt->cl;
> -
> -	dma_unmap_single(client->chan->mbox->dev, pkt->pa_base, pkt-
> >buf_size,
> -			 DMA_TO_DEVICE);
> -	kfree(pkt->va_base);
> -	kfree(pkt);
> -}
> -#endif
> -
>  static void mtk_drm_crtc_destroy(struct drm_crtc *crtc)
>  {
>  	struct mtk_drm_crtc *mtk_crtc = to_mtk_crtc(crtc);
> @@ -156,12 +115,9 @@ static void mtk_drm_crtc_destroy(struct drm_crtc
> *crtc)
>  
>  	mtk_mutex_put(mtk_crtc->mutex);
>  #if IS_REACHABLE(CONFIG_MTK_CMDQ)
> -	mtk_drm_cmdq_pkt_destroy(&mtk_crtc->cmdq_handle);
> -
> -	if (mtk_crtc->cmdq_client.chan) {
> -		mbox_free_channel(mtk_crtc->cmdq_client.chan);
> -		mtk_crtc->cmdq_client.chan = NULL;
> -	}
> +	cmdq_pkt_destroy(mtk_crtc->cmdq_handle);
> +	cmdq_mbox_destroy(mtk_crtc->cmdq_client);
> +	mtk_crtc->cmdq_client = NULL;
>  #endif
>  
>  	for (i = 0; i < mtk_crtc->ddp_comp_nr; i++) {
> @@ -288,7 +244,7 @@ static void ddp_cmdq_cb(struct mbox_client *cl,
> void *mssg)
>  {
>  	struct cmdq_cb_data *data = mssg;
>  	struct cmdq_client *cmdq_cl = container_of(cl, struct
> cmdq_client, client);
> -	struct mtk_drm_crtc *mtk_crtc = container_of(cmdq_cl, struct
> mtk_drm_crtc, cmdq_client);
> +	struct mtk_drm_crtc *mtk_crtc = (struct mtk_drm_crtc *)cmdq_cl-
> >priv;
>  	struct mtk_crtc_state *state;
>  	unsigned int i;
>  
> @@ -546,7 +502,7 @@ static void mtk_drm_crtc_update_config(struct
> mtk_drm_crtc *mtk_crtc,
>  				       bool needs_vblank)
>  {
>  #if IS_REACHABLE(CONFIG_MTK_CMDQ)
> -	struct cmdq_pkt *cmdq_handle = &mtk_crtc->cmdq_handle;
> +	struct cmdq_pkt *cmdq_handle = mtk_crtc->cmdq_handle;
>  #endif
>  	struct drm_crtc *crtc = &mtk_crtc->base;
>  	struct mtk_drm_private *priv = crtc->dev->dev_private;
> @@ -584,14 +540,14 @@ static void mtk_drm_crtc_update_config(struct
> mtk_drm_crtc *mtk_crtc,
>  		mtk_mutex_release(mtk_crtc->mutex);
>  	}
>  #if IS_REACHABLE(CONFIG_MTK_CMDQ)
> -	if (mtk_crtc->cmdq_client.chan) {
> -		mbox_flush(mtk_crtc->cmdq_client.chan, 2000);
> +	if (mtk_crtc->cmdq_client) {
> +		mbox_flush(mtk_crtc->cmdq_client->chan, 2000);
>  		cmdq_handle->cmd_buf_size = 0;
>  		cmdq_pkt_clear_event(cmdq_handle, mtk_crtc-
> >cmdq_event);
>  		cmdq_pkt_wfe(cmdq_handle, mtk_crtc->cmdq_event, false);
>  		mtk_crtc_ddp_config(crtc, cmdq_handle);
>  		cmdq_pkt_finalize(cmdq_handle);
> -		dma_sync_single_for_device(mtk_crtc->cmdq_client.chan-
> >mbox->dev,
> +		dma_sync_single_for_device(mtk_crtc->cmdq_client->chan-
> >mbox->dev,
>  					   cmdq_handle->pa_base,
>  					   cmdq_handle->cmd_buf_size,
>  					   DMA_TO_DEVICE);
> @@ -604,8 +560,8 @@ static void mtk_drm_crtc_update_config(struct
> mtk_drm_crtc *mtk_crtc,
>  		 */
>  		mtk_crtc->cmdq_vblank_cnt = 3;
>  
> -		mbox_send_message(mtk_crtc->cmdq_client.chan,
> cmdq_handle);
> -		mbox_client_txdone(mtk_crtc->cmdq_client.chan, 0);
> +		mbox_send_message(mtk_crtc->cmdq_client->chan,
> cmdq_handle);
> +		mbox_client_txdone(mtk_crtc->cmdq_client->chan, 0);
>  	}
>  #endif
>  	mtk_crtc->config_updating = false;
> @@ -619,7 +575,7 @@ static void mtk_crtc_ddp_irq(void *data)
>  	struct mtk_drm_private *priv = crtc->dev->dev_private;
>  
>  #if IS_REACHABLE(CONFIG_MTK_CMDQ)
> -	if (!priv->data->shadow_register && !mtk_crtc-
> >cmdq_client.chan)
> +	if (!priv->data->shadow_register && !mtk_crtc->cmdq_client)
>  		mtk_crtc_ddp_config(crtc, NULL);
>  	else if (mtk_crtc->cmdq_vblank_cnt > 0 && --mtk_crtc-
> >cmdq_vblank_cnt == 0)
>  		DRM_ERROR("mtk_crtc %d CMDQ execute command
> timeout!\n",
> @@ -722,7 +678,7 @@ static void mtk_drm_crtc_atomic_disable(struct
> drm_crtc *crtc,
>  	mtk_drm_crtc_update_config(mtk_crtc, false);
>  #if IS_REACHABLE(CONFIG_MTK_CMDQ)
>  	/* Wait for planes to be disabled by cmdq */
> -	if (mtk_crtc->cmdq_client.chan)
> +	if (mtk_crtc->cmdq_client)
>  		wait_event_timeout(mtk_crtc->cb_blocking_queue,
>  				   mtk_crtc->cmdq_vblank_cnt == 0,
>  				   msecs_to_jiffies(500));
> @@ -1002,19 +958,20 @@ int mtk_drm_crtc_create(struct drm_device
> *drm_dev,
>  
>  #if IS_REACHABLE(CONFIG_MTK_CMDQ)
>  	i = priv->mbox_index++;
> -	mtk_crtc->cmdq_client.client.dev = mtk_crtc->mmsys_dev;
> -	mtk_crtc->cmdq_client.client.tx_block = false;
> -	mtk_crtc->cmdq_client.client.knows_txdone = true;
> -	mtk_crtc->cmdq_client.client.rx_callback = ddp_cmdq_cb;
> -	mtk_crtc->cmdq_client.chan =
> -			mbox_request_channel(&mtk_crtc-
> >cmdq_client.client, i);
> -	if (IS_ERR(mtk_crtc->cmdq_client.chan)) {
> -		dev_dbg(dev, "mtk_crtc %d failed to create mailbox
> client, writing register by CPU now\n",
> -			drm_crtc_index(&mtk_crtc->base));
> -		mtk_crtc->cmdq_client.chan = NULL;
> +
> +	mtk_crtc->cmdq_client = cmdq_mbox_create(mtk_crtc->mmsys_dev,
> i);
> +	if (IS_ERR(mtk_crtc->cmdq_client)) {
> +		ret = PTR_ERR(mtk_crtc->cmdq_client);
> +		dev_dbg(dev, "Failed to create CMDQ client: %d\n",
> ret);
> +		mtk_crtc->cmdq_client = NULL;
> +		return 0;
>  	}
>  
> -	if (mtk_crtc->cmdq_client.chan) {
> +	/* Setup the CMDQ handler callback */
> +	mtk_crtc->cmdq_client->priv = mtk_crtc;
> +	mtk_crtc->cmdq_client->client.rx_callback = ddp_cmdq_cb;
> +
> +	if (mtk_crtc->cmdq_client) {
>  		ret = of_property_read_u32_index(priv->mutex_node,
>  						 "mediatek,gce-events",
>  						 i,
> @@ -1022,17 +979,15 @@ int mtk_drm_crtc_create(struct drm_device
> *drm_dev,
>  		if (ret) {
>  			dev_dbg(dev, "mtk_crtc %d failed to get
> mediatek,gce-events property\n",
>  				drm_crtc_index(&mtk_crtc->base));
> -			mbox_free_channel(mtk_crtc->cmdq_client.chan);
> -			mtk_crtc->cmdq_client.chan = NULL;
> +			cmdq_mbox_destroy(mtk_crtc->cmdq_client);
> +			mtk_crtc->cmdq_client = NULL;
>  		} else {
> -			ret = mtk_drm_cmdq_pkt_create(&mtk_crtc-
> >cmdq_client,
> -						      &mtk_crtc-
> >cmdq_handle,
> -						      PAGE_SIZE);
> +			mtk_crtc->cmdq_handle =
> cmdq_pkt_create(mtk_crtc->cmdq_client, PAGE_SIZE);
>  			if (ret) {
>  				dev_dbg(dev, "mtk_crtc %d failed to
> create cmdq packet\n",
>  					drm_crtc_index(&mtk_crtc-
> >base));
> -				mbox_free_channel(mtk_crtc-
> >cmdq_client.chan);
> -				mtk_crtc->cmdq_client.chan = NULL;
> +				cmdq_mbox_destroy(mtk_crtc-
> >cmdq_client);
> +				mtk_crtc->cmdq_client = NULL;
>  			}
>  		}
>  
> diff --git a/include/linux/soc/mediatek/mtk-cmdq.h
> b/include/linux/soc/mediatek/mtk-cmdq.h
> index 649955d2cf5c..2a1dc8b12db3 100644
> --- a/include/linux/soc/mediatek/mtk-cmdq.h
> +++ b/include/linux/soc/mediatek/mtk-cmdq.h
> @@ -25,6 +25,7 @@ struct cmdq_client_reg {
>  struct cmdq_client {
>  	struct mbox_client client;
>  	struct mbox_chan *chan;
> +	void *priv;
>  };
>  
>  #if IS_ENABLED(CONFIG_MTK_CMDQ)
> -- 
> 2.40.1