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Message-ID: <f9850c0c-a4a9-4d5f-eaa9-c1fd39b72870@nvidia.com>
Date: Tue, 6 Sep 2016 12:52:03 +0100
From: Jon Hunter <jonathanh@...dia.com>
To: Nicolin Chen <nicoleotsuka@...il.com>, <vinod.koul@...el.com>
CC: <linux-kernel@...r.kernel.org>, <linux-tegra@...r.kernel.org>,
<dmaengine@...r.kernel.org>, <gnurou@...il.com>,
<thierry.reding@...il.com>, <swarren@...dotorg.org>,
<ldewangan@...dia.com>
Subject: Re: [PATCH v2 2/2] dmaengine: tegra210-adma: Add memcpy support
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 <nicoleotsuka@...il.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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