Re: [PATCH] mmc: dw_mmc: Add support for pre_req and post_req

[Jaehoon Chung <jh80.chung@samsung.com>]

On 01/25/2012 02:12 PM, Seungwon Jeon wrote:

> Jaehoon Chung <jh80.chung@samsung.com> wrote:
>> Hi Mr Jeon..
>>
>> Are Pre_req and post_req used with only the IDMAC..?
> Currently internal dma is considered.
> Do you use system dma operation?

I used the IDMAC. 
My means...other dma system can also use this feature, right?
So i just asked to you..

Best Regards,
Jaehoon Chung

> 
>>
>> On 01/20/2012 01:05 PM, Seungwon Jeon wrote:
>>
>>> This patch implements pre_req and post_req in dw_mmc
>>> to support asynchronous mmc request.
>>>
>>> Signed-off-by: Seungwon Jeon <tgih.jun@samsung.com>
>>> ---
>>> NOTE:
>>>     Performance gains the following.
>>>     Sequential read and write improve 23% and 5% respectively.
>>>
>>>  drivers/mmc/host/dw_mmc.c |  136 ++++++++++++++++++++++++++++++++++++---------
>>>  1 files changed, 109 insertions(+), 27 deletions(-)
>>>
>>> diff --git a/drivers/mmc/host/dw_mmc.c b/drivers/mmc/host/dw_mmc.c
>>> index 0e34279..1fb8114 100644
>>> --- a/drivers/mmc/host/dw_mmc.c
>>> +++ b/drivers/mmc/host/dw_mmc.c
>>> @@ -297,14 +297,24 @@ static void dw_mci_stop_dma(struct dw_mci *host)
>>>  }
>>>
>>>  #ifdef CONFIG_MMC_DW_IDMAC
>>> +static int dw_mci_get_dma_dir(struct mmc_data *data)
>>> +{
>>> +	if (data->flags & MMC_DATA_WRITE)
>>> +		return DMA_TO_DEVICE;
>>> +	else
>>> +		return DMA_FROM_DEVICE;
>>> +}
>>> +
>>>  static void dw_mci_dma_cleanup(struct dw_mci *host)
>>>  {
>>>  	struct mmc_data *data = host->data;
>>>
>>>  	if (data)
>>> -		dma_unmap_sg(&host->pdev->dev, data->sg, data->sg_len,
>>> -			     ((data->flags & MMC_DATA_WRITE)
>>> -			      ? DMA_TO_DEVICE : DMA_FROM_DEVICE));
>>> +		if (!data->host_cookie)
>>> +			dma_unmap_sg(&host->pdev->dev,
>>> +				     data->sg,
>>> +				     data->sg_len,
>>> +				     dw_mci_get_dma_dir(data));
>>>  }
>>
>> 		if (!data->host_cookie)
>> 			dma_unmap_sg(&host->pdev->dev,
>> 				     data->sg, data->sg_len,
>> 				     dw_mci_get_dma_dir(data));
>> also the below code..
> Sorry... What's mean?
> 
> Thanks,
> Seungwon Jeon.
>>
>> Best Regards,
>> Jaehoon Chung
>>
>>>
>>>  static void dw_mci_idmac_stop_dma(struct dw_mci *host)
>>> @@ -420,26 +430,15 @@ static int dw_mci_idmac_init(struct dw_mci *host)
>>>  	return 0;
>>>  }
>>>
>>> -static struct dw_mci_dma_ops dw_mci_idmac_ops = {
>>> -	.init = dw_mci_idmac_init,
>>> -	.start = dw_mci_idmac_start_dma,
>>> -	.stop = dw_mci_idmac_stop_dma,
>>> -	.complete = dw_mci_idmac_complete_dma,
>>> -	.cleanup = dw_mci_dma_cleanup,
>>> -};
>>> -#endif /* CONFIG_MMC_DW_IDMAC */
>>> -
>>> -static int dw_mci_submit_data_dma(struct dw_mci *host, struct mmc_data *data)
>>> +static int dw_mci_pre_dma_transfer(struct dw_mci *host,
>>> +				   struct mmc_data *data,
>>> +				   bool next)
>>>  {
>>>  	struct scatterlist *sg;
>>> -	unsigned int i, direction, sg_len;
>>> -	u32 temp;
>>> -
>>> -	host->using_dma = 0;
>>> +	unsigned int i, sg_len;
>>>
>>> -	/* If we don't have a channel, we can't do DMA */
>>> -	if (!host->use_dma)
>>> -		return -ENODEV;
>>> +	if (!next && data->host_cookie)
>>> +		return data->host_cookie;
>>>
>>>  	/*
>>>  	 * We don't do DMA on "complex" transfers, i.e. with
>>> @@ -448,6 +447,7 @@ static int dw_mci_submit_data_dma(struct dw_mci *host, struct mmc_data *data)
>>>  	 */
>>>  	if (data->blocks * data->blksz < DW_MCI_DMA_THRESHOLD)
>>>  		return -EINVAL;
>>> +
>>>  	if (data->blksz & 3)
>>>  		return -EINVAL;
>>>
>>> @@ -456,15 +456,95 @@ static int dw_mci_submit_data_dma(struct dw_mci *host, struct mmc_data *data)
>>>  			return -EINVAL;
>>>  	}
>>>
>>> -	host->using_dma = 1;
>>> +	sg_len = dma_map_sg(&host->pdev->dev,
>>> +			    data->sg,
>>> +			    data->sg_len,
>>> +			    dw_mci_get_dma_dir(data));
>>> +	if (sg_len == 0)
>>> +		return -EINVAL;
>>>
>>> -	if (data->flags & MMC_DATA_READ)
>>> -		direction = DMA_FROM_DEVICE;
>>> -	else
>>> -		direction = DMA_TO_DEVICE;
>>> +	if (next)
>>> +		data->host_cookie = sg_len;
>>> +
>>> +	return sg_len;
>>> +}
>>>
>>> -	sg_len = dma_map_sg(&host->pdev->dev, data->sg, data->sg_len,
>>> -			    direction);
>>> +static void dw_mci_pre_req(struct mmc_host *mmc,
>>> +			   struct mmc_request *mrq,
>>> +			   bool is_first_req)
>>> +{
>>> +	struct dw_mci_slot *slot = mmc_priv(mmc);
>>> +	struct mmc_data *data = mrq->data;
>>> +
>>> +	if (!data)
>>> +		return;
>>> +
>>> +	if (data->host_cookie) {
>>> +		data->host_cookie = 0;
>>> +		return;
>>> +	}
>>> +
>>> +	if (slot->host->use_dma) {
>>> +		if (dw_mci_pre_dma_transfer(slot->host, mrq->data, 1) < 0)
>>> +			data->host_cookie = 0;
>>> +	}
>>> +}
>>> +
>>> +static void dw_mci_post_req(struct mmc_host *mmc,
>>> +			    struct mmc_request *mrq,
>>> +			    int err)
>>> +{
>>> +	struct dw_mci_slot *slot = mmc_priv(mmc);
>>> +	struct mmc_data *data = mrq->data;
>>> +
>>> +	if (!data)
>>> +		return;
>>> +
>>> +	if (slot->host->use_dma) {
>>> +		if (data->host_cookie)
>>> +			dma_unmap_sg(&slot->host->pdev->dev,
>>> +				     data->sg,
>>> +				     data->sg_len,
>>> +				     dw_mci_get_dma_dir(data));
>>> +		data->host_cookie = 0;
>>> +	}
>>> +}
>>> +
>>> +static struct dw_mci_dma_ops dw_mci_idmac_ops = {
>>> +	.init = dw_mci_idmac_init,
>>> +	.start = dw_mci_idmac_start_dma,
>>> +	.stop = dw_mci_idmac_stop_dma,
>>> +	.complete = dw_mci_idmac_complete_dma,
>>> +	.cleanup = dw_mci_dma_cleanup,
>>> +};
>>> +#else
>>> +static int dw_mci_pre_dma_transfer(struct dw_mci *host,
>>> +				   struct mmc_data *data,
>>> +				   bool next)
>>> +{
>>> +	return -ENOSYS;
>>> +}
>>> +
>>> +#define dw_mci_pre_req	NULL
>>> +#define dw_mci_post_req	NULL
>>> +#endif /* CONFIG_MMC_DW_IDMAC */
>>> +
>>> +static int dw_mci_submit_data_dma(struct dw_mci *host, struct mmc_data *data)
>>> +{
>>> +	int sg_len;
>>> +	u32 temp;
>>> +
>>> +	host->using_dma = 0;
>>> +
>>> +	/* If we don't have a channel, we can't do DMA */
>>> +	if (!host->use_dma)
>>> +		return -ENODEV;
>>> +
>>> +	sg_len = dw_mci_pre_dma_transfer(host, data, 0);
>>> +	if (sg_len < 0)
>>> +		return sg_len;
>>> +
>>> +	host->using_dma = 1;
>>>
>>>  	dev_vdbg(&host->pdev->dev,
>>>  		 "sd sg_cpu: %#lx sg_dma: %#lx sg_len: %d\n",
>>> @@ -795,6 +875,8 @@ static void dw_mci_enable_sdio_irq(struct mmc_host *mmc, int enb)
>>>
>>>  static const struct mmc_host_ops dw_mci_ops = {
>>>  	.request		= dw_mci_request,
>>> +	.pre_req		= dw_mci_pre_req,
>>> +	.post_req		= dw_mci_post_req,
>>>  	.set_ios		= dw_mci_set_ios,
>>>  	.get_ro			= dw_mci_get_ro,
>>>  	.get_cd			= dw_mci_get_cd,
>>
>>
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