[PATCH v22 4/4] soc: mediatek: Add Mediatek CMDQ helper

CK Hu
2018-06-28T10:41:56Z

Hi, Houlong:

Some inline comment.

On Wed, 2018-06-27 at 19:16 +0800, Houlong Wei wrote:
> Add Mediatek CMDQ helper to create CMDQ packet and assemble GCE op code.
>
> Signed-off-by: Houlong Wei <houlong.wei@mediatek.com>
> Signed-off-by: HS Liao <hs.liao@mediatek.com>
> ---
> drivers/soc/mediatek/Kconfig | 12 ++
> drivers/soc/mediatek/Makefile | 1 +
> drivers/soc/mediatek/mtk-cmdq-helper.c | 258 ++++++++++++++++++++++++++++++++
> include/linux/soc/mediatek/mtk-cmdq.h | 132 ++++++++++++++++
> 4 files changed, 403 insertions(+)
> create mode 100644 drivers/soc/mediatek/mtk-cmdq-helper.c
> create mode 100644 include/linux/soc/mediatek/mtk-cmdq.h
>
> diff --git a/drivers/soc/mediatek/Kconfig b/drivers/soc/mediatek/Kconfig
> index a7d0667..17bd759 100644
> --- a/drivers/soc/mediatek/Kconfig
> +++ b/drivers/soc/mediatek/Kconfig
> @@ -4,6 +4,18 @@
> menu "MediaTek SoC drivers"
> depends on ARCH_MEDIATEK || COMPILE_TEST
>

[...]

> +
> +int cmdq_pkt_wfe(struct cmdq_pkt *pkt, u32 event)
> +{
> + u32 arg_b;
> +
> + if (event >= CMDQ_MAX_EVENT || event < 0)

The type of event is 'u32', so checking 'event < 0' is redundant.

> + return -EINVAL;
> +
> + /*
> + * WFE arg_b
> + * bit 0-11: wait value
> + * bit 15: 1 - wait, 0 - no wait
> + * bit 16-27: update value
> + * bit 31: 1 - update, 0 - no update
> + */
> + arg_b = CMDQ_WFE_UPDATE | CMDQ_WFE_WAIT | CMDQ_WFE_WAIT_VALUE;
> +
> + return cmdq_pkt_append_command(pkt, CMDQ_CODE_WFE, event, arg_b);
> +}
> +EXPORT_SYMBOL(cmdq_pkt_wfe);
> +
> +int cmdq_pkt_clear_event(struct cmdq_pkt *pkt, u32 event)
> +{
> + if (event >= CMDQ_MAX_EVENT || event < 0)

The type of event is 'u32', so checking 'event < 0' is redundant.

> + return -EINVAL;
> +
> + return cmdq_pkt_append_command(pkt, CMDQ_CODE_WFE, event,
> + CMDQ_WFE_UPDATE);
> +}
> +EXPORT_SYMBOL(cmdq_pkt_clear_event);
> +
> +static int cmdq_pkt_finalize(struct cmdq_pkt *pkt)
> +{
> + int err;
> +
> + if (cmdq_pkt_is_finalized(pkt))
> + return 0;
> +
> + /* insert EOC and generate IRQ for each command iteration */
> + err = cmdq_pkt_append_command(pkt, CMDQ_CODE_EOC, 0, CMDQ_EOC_IRQ_EN);
> + if (err < 0)
> + return err;
> +
> + /* JUMP to end */
> + err = cmdq_pkt_append_command(pkt, CMDQ_CODE_JUMP, 0, CMDQ_JUMP_PASS);
> + if (err < 0)
> + return err;
> +
> + return 0;
> +}
> +
> +int cmdq_pkt_flush_async(struct cmdq_client *client, struct cmdq_pkt *pkt,
> + cmdq_async_flush_cb cb, void *data)
> +{
> + int err;
> + struct device *dev;
> + dma_addr_t dma_addr;
> +
> + err = cmdq_pkt_finalize(pkt);
> + if (err < 0)
> + return err;
> +
> + dev = client->chan->mbox->dev;
> + dma_addr = dma_map_single(dev, pkt->va_base, pkt->cmd_buf_size,
> + DMA_TO_DEVICE);

You map here, but I could not find unmap, so the unmap should be done in
client driver. I would prefer a symmetric map/unmap which means that
both map and unmap are done in client driver. I think you put map here
because you should map after finalize. Therefore, export
cmdq_pkt_finalize() to client driver and let client do finalize, so
there is no finalize in flush function. This method have a benefit that
if client reuse command buffer, it need not to map/unmap frequently.

Regards,
CK

> + if (dma_mapping_error(dev, dma_addr)) {
> + dev_err(client->chan->mbox->dev, "dma map failed\n");
> + return -ENOMEM;
> + }
> +
> + pkt->pa_base = dma_addr;
> + pkt->cb.cb = cb;
> + pkt->cb.data = data;
> +
> + mbox_send_message(client->chan, pkt);
> + /* We can send next packet immediately, so just call txdone. */
> + mbox_client_txdone(client->chan, 0);
> +
> + return 0;
> +}
> +EXPORT_SYMBOL(cmdq_pkt_flush_async);
> +
> +struct cmdq_flush_completion {
> + struct completion cmplt;
> + bool err;
> +};
> +
> +static void cmdq_pkt_flush_cb(struct cmdq_cb_data data)
> +{
> + struct cmdq_flush_completion *cmplt = data.data;
> +
> + cmplt->err = data.err;
> + complete(&cmplt->cmplt);
> +}
> +
> +int cmdq_pkt_flush(struct cmdq_client *client, struct cmdq_pkt *pkt)
> +{
> + struct cmdq_flush_completion cmplt;
> + int err;
> +
> + init_completion(&cmplt.cmplt);
> + err = cmdq_pkt_flush_async(client, pkt, cmdq_pkt_flush_cb, &cmplt);
> + if (err < 0)
> + return err;
> + wait_for_completion(&cmplt.cmplt);
> +
> + return cmplt.err ? -EFAULT : 0;
> +}
> +EXPORT_SYMBOL(cmdq_pkt_flush); …