Re: [PATCH V2 04/27] mmc: mmci: introduce dma_priv pointer to mmci_host

[Ulf Hansson <ulf.hansson@linaro.org>]

On 21 September 2018 at 11:45, Ludovic Barre <ludovic.Barre@st.com> wrote:
> From: Ludovic Barre <ludovic.barre@st.com>
>
> This patch introduces dma_priv pointer to define specific
> needs for each dma engine. This patch is needed to prepare
> sdmmc variant with internal dma which not use dmaengine API.
>
> Signed-off-by: Ludovic Barre <ludovic.barre@st.com>
> ---
> change v2:
> -rename specific dma engine structure to mmci_dmae_next/priv
> -remove dma prefixe of mmci_dmae_priv fields, rename "current"
> field to "cur" this avoid build issue with "current" defined
> in include/asm-generic/current.h
>
>  drivers/mmc/host/mmci.c | 155 ++++++++++++++++++++++++++++++------------------
>  drivers/mmc/host/mmci.h |  18 +-----
>  2 files changed, 99 insertions(+), 74 deletions(-)
>
> diff --git a/drivers/mmc/host/mmci.c b/drivers/mmc/host/mmci.c
> index 2f845f3..6de7c8d 100644
> --- a/drivers/mmc/host/mmci.c
> +++ b/drivers/mmc/host/mmci.c
> @@ -415,31 +415,57 @@ static void mmci_init_sg(struct mmci_host *host, struct mmc_data *data)
>   * no custom DMA interfaces are supported.
>   */
>  #ifdef CONFIG_DMA_ENGINE
> +struct mmci_dmae_next {
> +       struct dma_async_tx_descriptor *desc;
> +       struct dma_chan *chan;
> +       s32 cookie;
> +};
> +
> +struct mmci_dmae_priv {
> +       struct dma_chan *cur;
> +       struct dma_chan *rx_channel;
> +       struct dma_chan *tx_channel;
> +       struct dma_async_tx_descriptor  *desc_current;
> +       struct mmci_dmae_next next_data;
> +       bool in_progress;

I am wondering whether it would make sense to keep the "bool
in_progress" in the struct mmci_host. I guess it will be used for all
dma variants anyway!?

> +};
> +
> +#define mmci_dmae_inprogress(dmae) ((dmae)->in_progress)
> +
>  static int mmci_dma_setup(struct mmci_host *host)
>  {
>         const char *rxname, *txname;
> +       struct mmci_dmae_priv *dmae;
> +
> +       dmae = devm_kzalloc(mmc_dev(host->mmc), sizeof(*dmae), GFP_KERNEL);
> +       if (!dmae)
> +               return -ENOMEM;
>
> -       host->dma_rx_channel = dma_request_slave_channel(mmc_dev(host->mmc), "rx");
> -       host->dma_tx_channel = dma_request_slave_channel(mmc_dev(host->mmc), "tx");
> +       host->dma_priv = dmae;
> +
> +       dmae->rx_channel = dma_request_slave_channel(mmc_dev(host->mmc),
> +                                                    "rx");
> +       dmae->tx_channel = dma_request_slave_channel(mmc_dev(host->mmc),
> +                                                    "tx");
>
>         /* initialize pre request cookie */
> -       host->next_data.cookie = 1;
> +       dmae->next_data.cookie = 1;
>
>         /*
>          * If only an RX channel is specified, the driver will
>          * attempt to use it bidirectionally, however if it is
>          * is specified but cannot be located, DMA will be disabled.
>          */
> -       if (host->dma_rx_channel && !host->dma_tx_channel)
> -               host->dma_tx_channel = host->dma_rx_channel;
> +       if (dmae->rx_channel && !dmae->tx_channel)
> +               dmae->tx_channel = dmae->rx_channel;
>
> -       if (host->dma_rx_channel)
> -               rxname = dma_chan_name(host->dma_rx_channel);
> +       if (dmae->rx_channel)
> +               rxname = dma_chan_name(dmae->rx_channel);
>         else
>                 rxname = "none";
>
> -       if (host->dma_tx_channel)
> -               txname = dma_chan_name(host->dma_tx_channel);
> +       if (dmae->tx_channel)
> +               txname = dma_chan_name(dmae->tx_channel);
>         else
>                 txname = "none";
>
> @@ -450,15 +476,15 @@ static int mmci_dma_setup(struct mmci_host *host)
>          * Limit the maximum segment size in any SG entry according to
>          * the parameters of the DMA engine device.
>          */
> -       if (host->dma_tx_channel) {
> -               struct device *dev = host->dma_tx_channel->device->dev;
> +       if (dmae->tx_channel) {
> +               struct device *dev = dmae->tx_channel->device->dev;
>                 unsigned int max_seg_size = dma_get_max_seg_size(dev);
>
>                 if (max_seg_size < host->mmc->max_seg_size)
>                         host->mmc->max_seg_size = max_seg_size;
>         }
> -       if (host->dma_rx_channel) {
> -               struct device *dev = host->dma_rx_channel->device->dev;
> +       if (dmae->rx_channel) {
> +               struct device *dev = dmae->rx_channel->device->dev;
>                 unsigned int max_seg_size = dma_get_max_seg_size(dev);
>
>                 if (max_seg_size < host->mmc->max_seg_size)
> @@ -477,21 +503,24 @@ static int mmci_dma_setup(struct mmci_host *host)
>   */
>  static inline void mmci_dma_release(struct mmci_host *host)
>  {
> -       if (host->dma_rx_channel)
> -               dma_release_channel(host->dma_rx_channel);
> -       if (host->dma_tx_channel)
> -               dma_release_channel(host->dma_tx_channel);
> -       host->dma_rx_channel = host->dma_tx_channel = NULL;
> +       struct mmci_dmae_priv *dmae = host->dma_priv;
> +
> +       if (dmae->rx_channel)
> +               dma_release_channel(dmae->rx_channel);
> +       if (dmae->tx_channel)
> +               dma_release_channel(dmae->tx_channel);
> +       dmae->rx_channel = dmae->tx_channel = NULL;
>  }
>
>  static void mmci_dma_unmap(struct mmci_host *host, struct mmc_data *data)
>  {
> +       struct mmci_dmae_priv *dmae = host->dma_priv;
>         struct dma_chan *chan;
>
>         if (data->flags & MMC_DATA_READ)
> -               chan = host->dma_rx_channel;
> +               chan = dmae->rx_channel;
>         else
> -               chan = host->dma_tx_channel;
> +               chan = dmae->tx_channel;
>
>         dma_unmap_sg(chan->device->dev, data->sg, data->sg_len,
>                      mmc_get_dma_dir(data));
> @@ -499,14 +528,16 @@ static void mmci_dma_unmap(struct mmci_host *host, struct mmc_data *data)
>
>  static void mmci_dma_data_error(struct mmci_host *host)
>  {
> -       if (!dma_inprogress(host))
> +       struct mmci_dmae_priv *dmae = host->dma_priv;
> +
> +       if (!mmci_dmae_inprogress(dmae))
>                 return;
>
>         dev_err(mmc_dev(host->mmc), "error during DMA transfer!\n");
> -       dmaengine_terminate_all(host->dma_current);
> -       host->dma_in_progress = false;
> -       host->dma_current = NULL;
> -       host->dma_desc_current = NULL;
> +       dmaengine_terminate_all(dmae->cur);
> +       dmae->in_progress = false;
> +       dmae->cur = NULL;
> +       dmae->desc_current = NULL;
>         host->data->host_cookie = 0;
>
>         mmci_dma_unmap(host, host->data);
> @@ -514,10 +545,11 @@ static void mmci_dma_data_error(struct mmci_host *host)
>
>  static void mmci_dma_finalize(struct mmci_host *host, struct mmc_data *data)
>  {
> +       struct mmci_dmae_priv *dmae = host->dma_priv;
>         u32 status;
>         int i;
>
> -       if (!dma_inprogress(host))
> +       if (!mmci_dmae_inprogress(dmae))
>                 return;
>
>         /* Wait up to 1ms for the DMA to complete */
> @@ -551,9 +583,9 @@ static void mmci_dma_finalize(struct mmci_host *host, struct mmc_data *data)
>                 mmci_dma_release(host);
>         }
>
> -       host->dma_in_progress = false;
> -       host->dma_current = NULL;
> -       host->dma_desc_current = NULL;
> +       dmae->in_progress = false;
> +       dmae->cur = NULL;
> +       dmae->desc_current = NULL;
>  }
>
>  /* prepares DMA channel and DMA descriptor, returns non-zero on failure */
> @@ -561,6 +593,7 @@ static int __mmci_dma_prep_data(struct mmci_host *host, struct mmc_data *data,
>                                 struct dma_chan **dma_chan,
>                                 struct dma_async_tx_descriptor **dma_desc)
>  {
> +       struct mmci_dmae_priv *dmae = host->dma_priv;
>         struct variant_data *variant = host->variant;
>         struct dma_slave_config conf = {
>                 .src_addr = host->phybase + MMCIFIFO,
> @@ -579,10 +612,10 @@ static int __mmci_dma_prep_data(struct mmci_host *host, struct mmc_data *data,
>
>         if (data->flags & MMC_DATA_READ) {
>                 conf.direction = DMA_DEV_TO_MEM;
> -               chan = host->dma_rx_channel;
> +               chan = dmae->rx_channel;
>         } else {
>                 conf.direction = DMA_MEM_TO_DEV;
> -               chan = host->dma_tx_channel;
> +               chan = dmae->tx_channel;
>         }
>
>         /* If there's no DMA channel, fall back to PIO */
> @@ -622,26 +655,31 @@ static int __mmci_dma_prep_data(struct mmci_host *host, struct mmc_data *data,
>  static inline int mmci_dma_prep_data(struct mmci_host *host,
>                                      struct mmc_data *data)
>  {
> +       struct mmci_dmae_priv *dmae = host->dma_priv;
> +
>         /* Check if next job is already prepared. */
> -       if (host->dma_current && host->dma_desc_current)
> +       if (dmae->cur && dmae->desc_current)
>                 return 0;
>
>         /* No job were prepared thus do it now. */
> -       return __mmci_dma_prep_data(host, data, &host->dma_current,
> -                                   &host->dma_desc_current);
> +       return __mmci_dma_prep_data(host, data, &dmae->cur,
> +                                   &dmae->desc_current);
>  }
>
>  static inline int mmci_dma_prep_next(struct mmci_host *host,
>                                      struct mmc_data *data)
>  {
> -       struct mmci_host_next *nd = &host->next_data;
> -       return __mmci_dma_prep_data(host, data, &nd->dma_chan, &nd->dma_desc);
> +       struct mmci_dmae_priv *dmae = host->dma_priv;
> +       struct mmci_dmae_next *nd = &dmae->next_data;
> +
> +       return __mmci_dma_prep_data(host, data, &nd->chan, &nd->desc);
>  }
>
>  static int mmci_dma_start_data(struct mmci_host *host, unsigned int datactrl)
>  {
> -       int ret;
> +       struct mmci_dmae_priv *dmae = host->dma_priv;
>         struct mmc_data *data = host->data;
> +       int ret;

Looks like "white space". Anyway, please avoid move the declaration of
ret, unless needed.

>
>         ret = mmci_dma_prep_data(host, host->data);
>         if (ret)
> @@ -651,9 +689,9 @@ static int mmci_dma_start_data(struct mmci_host *host, unsigned int datactrl)
>         dev_vdbg(mmc_dev(host->mmc),
>                  "Submit MMCI DMA job, sglen %d blksz %04x blks %04x flags %08x\n",
>                  data->sg_len, data->blksz, data->blocks, data->flags);
> -       host->dma_in_progress = true;
> -       dmaengine_submit(host->dma_desc_current);
> -       dma_async_issue_pending(host->dma_current);
> +       dmae->in_progress = true;
> +       dmaengine_submit(dmae->desc_current);
> +       dma_async_issue_pending(dmae->cur);
>
>         if (host->variant->qcom_dml)
>                 dml_start_xfer(host, data);
> @@ -675,22 +713,24 @@ static int mmci_dma_start_data(struct mmci_host *host, unsigned int datactrl)
>
>  static void mmci_get_next_data(struct mmci_host *host, struct mmc_data *data)
>  {
> -       struct mmci_host_next *next = &host->next_data;
> +       struct mmci_dmae_priv *dmae = host->dma_priv;
> +       struct mmci_dmae_next *next = &dmae->next_data;
>
>         WARN_ON(data->host_cookie && data->host_cookie != next->cookie);
> -       WARN_ON(!data->host_cookie && (next->dma_desc || next->dma_chan));
> +       WARN_ON(!data->host_cookie && (next->desc || next->chan));
>
> -       host->dma_desc_current = next->dma_desc;
> -       host->dma_current = next->dma_chan;
> -       next->dma_desc = NULL;
> -       next->dma_chan = NULL;
> +       dmae->desc_current = next->desc;
> +       dmae->cur = next->chan;
> +       next->desc = NULL;
> +       next->chan = NULL;
>  }
>
>  static void mmci_pre_request(struct mmc_host *mmc, struct mmc_request *mrq)
>  {
>         struct mmci_host *host = mmc_priv(mmc);
> +       struct mmci_dmae_priv *dmae = host->dma_priv;
>         struct mmc_data *data = mrq->data;
> -       struct mmci_host_next *nd = &host->next_data;
> +       struct mmci_dmae_next *nd = &dmae->next_data;
>
>         if (!data)
>                 return;
> @@ -708,6 +748,7 @@ static void mmci_post_request(struct mmc_host *mmc, struct mmc_request *mrq,
>                               int err)
>  {
>         struct mmci_host *host = mmc_priv(mmc);
> +       struct mmci_dmae_priv *dmae = host->dma_priv;
>         struct mmc_data *data = mrq->data;
>
>         if (!data || !data->host_cookie)
> @@ -716,24 +757,24 @@ static void mmci_post_request(struct mmc_host *mmc, struct mmc_request *mrq,
>         mmci_dma_unmap(host, data);
>
>         if (err) {
> -               struct mmci_host_next *next = &host->next_data;
> +               struct mmci_dmae_next *next = &dmae->next_data;
>                 struct dma_chan *chan;
>                 if (data->flags & MMC_DATA_READ)
> -                       chan = host->dma_rx_channel;
> +                       chan = dmae->rx_channel;
>                 else
> -                       chan = host->dma_tx_channel;
> +                       chan = dmae->tx_channel;
>                 dmaengine_terminate_all(chan);
>
> -               if (host->dma_desc_current == next->dma_desc)
> -                       host->dma_desc_current = NULL;
> +               if (dmae->desc_current == next->desc)
> +                       dmae->desc_current = NULL;
>
> -               if (host->dma_current == next->dma_chan) {
> -                       host->dma_in_progress = false;
> -                       host->dma_current = NULL;
> +               if (dmae->cur == next->chan) {
> +                       dmae->in_progress = false;
> +                       dmae->cur = NULL;
>                 }
>
> -               next->dma_desc = NULL;
> -               next->dma_chan = NULL;
> +               next->desc = NULL;
> +               next->chan = NULL;
>                 data->host_cookie = 0;
>         }
>  }
> diff --git a/drivers/mmc/host/mmci.h b/drivers/mmc/host/mmci.h
> index 06299ac..1e9a45b 100644
> --- a/drivers/mmc/host/mmci.h
> +++ b/drivers/mmc/host/mmci.h
> @@ -276,12 +276,6 @@ struct mmci_host_ops {
>         int (*dma_setup)(struct mmci_host *host);
>  };
>
> -struct mmci_host_next {
> -       struct dma_async_tx_descriptor  *dma_desc;
> -       struct dma_chan                 *dma_chan;
> -       s32                             cookie;
> -};
> -
>  struct mmci_host {
>         phys_addr_t             phybase;
>         void __iomem            *base;
> @@ -323,16 +317,6 @@ struct mmci_host {
>         unsigned int            size;
>         int (*get_rx_fifocnt)(struct mmci_host *h, u32 status, int remain);
>
> -#ifdef CONFIG_DMA_ENGINE
> -       /* DMA stuff */
> -       struct dma_chan         *dma_current;
> -       struct dma_chan         *dma_rx_channel;
> -       struct dma_chan         *dma_tx_channel;
> -       struct dma_async_tx_descriptor  *dma_desc_current;
> -       struct mmci_host_next   next_data;
> -       bool                    dma_in_progress;
> -
> -#define dma_inprogress(host)   ((host)->dma_in_progress)
> -#endif
> +       void                    *dma_priv;
>  };
>
> --
> 2.7.4
>

Kind regards
Uffe