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Subject: Re: [PATCH V2 04/27] mmc: mmci: introduce dma_priv pointer to
 mmci_host
To:     Ulf Hansson <ulf.hansson@linaro.org>
CC:     Rob Herring <robh+dt@kernel.org>,
        Maxime Coquelin <mcoquelin.stm32@gmail.com>,
        Alexandre Torgue <alexandre.torgue@st.com>,
        Benjamin Gaignard <benjamin.gaignard@linaro.org>,
        Gerald Baeza <gerald.baeza@st.com>,
        Loic Pallardy <loic.pallardy@st.com>,
        Linux ARM <linux-arm-kernel@lists.infradead.org>,
        Linux Kernel Mailing List <linux-kernel@vger.kernel.org>,
        DTML <devicetree@vger.kernel.org>,
        "linux-mmc@vger.kernel.org" <linux-mmc@vger.kernel.org>,
        <linux-stm32@st-md-mailman.stormreply.com>
References: <1537523181-14578-1-git-send-email-ludovic.Barre@st.com>
 <1537523181-14578-5-git-send-email-ludovic.Barre@st.com>
 <CAPDyKFqQNN9X+x=pg9TOArT4-Tx9jNkpM2T+rAxQj-rzHXC0OA@mail.gmail.com>
From:   Ludovic BARRE <ludovic.barre@st.com>
Message-ID: <42b6a3dc-df03-9ba6-7863-8791007b3432@st.com>
Date:   Tue, 25 Sep 2018 09:19:21 +0200
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On 09/24/2018 08:52 PM, Ulf Hansson wrote:
> 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!?

Today it's only use in dma_engine config, not used by sdmmc variant.
But it's could moved to mmci_host structure, no problem.

> 
>> +};
>> +
>> +#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.

Ok

> 
>>
>>          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
>