On 03/09/16 01:32, Nicolin Chen wrote:
> ADMA supports non-flow controlled Memory-to-Memory direction
> transactions. So this patch just adds an initial support for
> that. It passed a simple dmatest:
>         echo dma1chan0 > /sys/module/dmatest/parameters/channel
>       echo 1024 > /sys/module/dmatest/parameters/iterations
>       echo 0 > /sys/module/dmatest/parameters/dmatest
>       echo 1 > /sys/module/dmatest/parameters/run
>       dmesg | grep dmatest
> Started 1 threads using dma1chan0
> dma1chan0-copy0: summary 1024 tests, 0 failures 2054 iops 16520 KB/s (0)
> 
> Signed-off-by: Nicolin Chen <nicoleots...@gmail.com>
> ---
>  drivers/dma/tegra210-adma.c | 95 
> +++++++++++++++++++++++++++++++++++++++------
>  1 file changed, 83 insertions(+), 12 deletions(-)
> 
> diff --git a/drivers/dma/tegra210-adma.c b/drivers/dma/tegra210-adma.c
> index 5b5d298..d62b373 100644
> --- a/drivers/dma/tegra210-adma.c
> +++ b/drivers/dma/tegra210-adma.c
> @@ -42,9 +42,14 @@
>  #define ADMA_CH_CTRL_RX_REQ(val)                     (((val) & 0xf) << 24)
>  #define ADMA_CH_CTRL_RX_REQ_MAX                              10
>  #define ADMA_CH_CTRL_DIR(val)                                (((val) & 0xf) 
> << 12)
> +#define ADMA_CH_CTRL_DIR_MEM2MEM                     1
>  #define ADMA_CH_CTRL_DIR_AHUB2MEM                    2
>  #define ADMA_CH_CTRL_DIR_MEM2AHUB                    4
> -#define ADMA_CH_CTRL_MODE_CONTINUOUS                 (2 << 8)
> +#define ADMA_CH_CTRL_DIR_AHUB2AHUB                   8
> +#define ADMA_CH_CTRL_MODE(val)                               (((val) & 0x7) 
> << 8)
> +#define ADMA_CH_CTRL_MODE_ONCE                               1
> +#define ADMA_CH_CTRL_MODE_CONTINUOUS                 2
> +#define ADMA_CH_CTRL_MODE_LINKED_LIST                        4
>  #define ADMA_CH_CTRL_FLOWCTRL_EN                     BIT(1)
>  
>  #define ADMA_CH_CONFIG                                       0x28
> @@ -264,6 +269,9 @@ static int tegra_adma_request_alloc(struct 
> tegra_adma_chan *tdc,
>               }
>               break;
>  
> +     case DMA_MEM_TO_MEM:
> +             break;
> +
>       default:
>               dev_WARN(tdma->dev, "channel %s has invalid transfer type\n",
>                        dma_chan_name(&tdc->vc.chan));
> @@ -292,6 +300,9 @@ static void tegra_adma_request_free(struct 
> tegra_adma_chan *tdc)
>               clear_bit(tdc->sreq_index, &tdma->rx_requests_reserved);
>               break;
>  
> +     case DMA_MEM_TO_MEM:
> +             break;
> +
>       default:
>               dev_WARN(tdma->dev, "channel %s has invalid transfer type\n",
>                        dma_chan_name(&tdc->vc.chan));
> @@ -409,8 +420,14 @@ static irqreturn_t tegra_adma_isr(int irq, void *dev_id)
>               return IRQ_NONE;
>       }
>  
> -     if (tdc->desc->cyclic)
> +     if (tdc->desc->cyclic) {
>               vchan_cyclic_callback(&tdc->desc->vd);
> +     } else {
> +             /* Disable the channel */
> +             tdma_ch_write(tdc, ADMA_CH_CMD, 0);
> +             vchan_cookie_complete(&tdc->desc->vd);
> +             tdc->desc = NULL;
> +     }
>  
>       spin_unlock_irqrestore(&tdc->vc.lock, flags);
>  
> @@ -488,42 +505,59 @@ static enum dma_status tegra_adma_tx_status(struct 
> dma_chan *dc,
>  static int tegra_adma_set_xfer_params(struct tegra_adma_chan *tdc,
>                                     struct tegra_adma_desc *desc,
>                                     dma_addr_t buf_addr,
> +                                   dma_addr_t buf_addr2,
>                                     enum dma_transfer_direction direction)
>  {
>       struct tegra_adma_chan_regs *ch_regs = &desc->ch_regs;
> -     unsigned int burst_size, adma_dir;
> +     unsigned int num_periods = desc->num_periods;
> +     unsigned int burst_size, adma_dir, adma_mode;
>  
> -     if (desc->num_periods > ADMA_CH_CONFIG_MAX_BUFS)
> +     if (num_periods > ADMA_CH_CONFIG_MAX_BUFS)
>               return -EINVAL;
>  
>       switch (direction) {
>       case DMA_MEM_TO_DEV:
>               adma_dir = ADMA_CH_CTRL_DIR_MEM2AHUB;
>               burst_size = fls(tdc->sconfig.dst_maxburst);
> -             ch_regs->config = ADMA_CH_CONFIG_SRC_BUF(desc->num_periods - 1);
> -             ch_regs->ctrl = ADMA_CH_CTRL_TX_REQ(tdc->sreq_index);
> +             ch_regs->config = ADMA_CH_CONFIG_SRC_BUF(num_periods - 1);
> +             ch_regs->ctrl = ADMA_CH_CTRL_TX_REQ(tdc->sreq_index) |
> +                             ADMA_CH_CTRL_FLOWCTRL_EN;
>               ch_regs->src_addr = buf_addr;
>               break;
>  
>       case DMA_DEV_TO_MEM:
>               adma_dir = ADMA_CH_CTRL_DIR_AHUB2MEM;
>               burst_size = fls(tdc->sconfig.src_maxburst);
> -             ch_regs->config = ADMA_CH_CONFIG_TRG_BUF(desc->num_periods - 1);
> -             ch_regs->ctrl = ADMA_CH_CTRL_RX_REQ(tdc->sreq_index);
> +             ch_regs->config = ADMA_CH_CONFIG_TRG_BUF(num_periods - 1);
> +             ch_regs->ctrl = ADMA_CH_CTRL_RX_REQ(tdc->sreq_index) |
> +                             ADMA_CH_CTRL_FLOWCTRL_EN;
>               ch_regs->trg_addr = buf_addr;
>               break;
>  
> +     case DMA_MEM_TO_MEM:
> +             adma_dir = ADMA_CH_CTRL_DIR_MEM2MEM;
> +             burst_size = ADMA_CH_CONFIG_BURST_16;
> +             ch_regs->config = ADMA_CH_CONFIG_SRC_BUF(num_periods - 1) |
> +                               ADMA_CH_CONFIG_TRG_BUF(num_periods - 1);
> +             ch_regs->src_addr = buf_addr;
> +             ch_regs->trg_addr = buf_addr2;
> +             break;
> +
>       default:
>               dev_err(tdc2dev(tdc), "DMA direction is not supported\n");
>               return -EINVAL;
>       }
>  
> +     if (desc->cyclic)
> +             adma_mode = ADMA_CH_CTRL_MODE_CONTINUOUS;
> +     else
> +             adma_mode = ADMA_CH_CTRL_MODE_ONCE;
> +
>       if (!burst_size || burst_size > ADMA_CH_CONFIG_BURST_16)
>               burst_size = ADMA_CH_CONFIG_BURST_16;
>  
>       ch_regs->ctrl |= ADMA_CH_CTRL_DIR(adma_dir) |
> -                      ADMA_CH_CTRL_MODE_CONTINUOUS |
> -                      ADMA_CH_CTRL_FLOWCTRL_EN;
> +                      ADMA_CH_CTRL_MODE(adma_mode);
>       ch_regs->config |= ADMA_CH_CONFIG_BURST_SIZE(burst_size);
>       ch_regs->config |= ADMA_CH_CONFIG_WEIGHT_FOR_WRR(1);
>       ch_regs->fifo_ctrl = ADMA_CH_FIFO_CTRL_DEFAULT;
> @@ -564,7 +598,39 @@ static struct dma_async_tx_descriptor 
> *tegra_adma_prep_dma_cyclic(
>       desc->period_len = period_len;
>       desc->num_periods = buf_len / period_len;
>  
> -     if (tegra_adma_set_xfer_params(tdc, desc, buf_addr, direction)) {
> +     if (tegra_adma_set_xfer_params(tdc, desc, buf_addr, 0, direction)) {
> +             kfree(desc);
> +             return NULL;
> +     }
> +
> +     return vchan_tx_prep(&tdc->vc, &desc->vd, flags);
> +}
> +
> +static struct dma_async_tx_descriptor *tegra_adma_prep_dma_memcpy(
> +     struct dma_chan *dc, dma_addr_t dest, dma_addr_t src,
> +     size_t buf_len, unsigned long flags)
> +{
> +     struct tegra_adma_chan *tdc = to_tegra_adma_chan(dc);
> +     struct device *dev = dc->device->dev;
> +     struct tegra_adma_desc *desc = NULL;
> +
> +     dev_dbg(dev, "%s channel: %d src=0x%llx dst=0x%llx len=%zu\n",
> +             __func__, dc->chan_id, (unsigned long long)src,
> +             (unsigned long long)dest, buf_len);
> +
> +     if (unlikely(!tdc || !buf_len))
> +             return NULL;
> +
> +     desc = kzalloc(sizeof(*desc), GFP_NOWAIT);
> +     if (!desc)
> +             return NULL;
> +
> +     /* TODO: ADMA should support up to 8 chunks or periods */
> +     desc->num_periods = 1;
> +     desc->buf_len = buf_len;
> +     desc->period_len = buf_len;

What would be the benefit of using 8 periods here? My understanding is
that you will get an interrupt per period and do you really want this
for memcpy?

Cheers
Jon

-- 
nvpublic

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