[PATCH v2 2/2] dmaengine: tegra210-adma: Add memcpy support

From: Nicolin Chen
Date: Fri Sep 02 2016 - 20:34:24 EST


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@xxxxxxxxx>
---
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;
+
+ if (tegra_adma_set_xfer_params(tdc, desc, src, dest, DMA_MEM_TO_MEM)) {
kfree(desc);
return NULL;
}
@@ -741,6 +807,7 @@ static int tegra_adma_probe(struct platform_device *pdev)
dma_cap_set(DMA_SLAVE, tdma->dma_dev.cap_mask);
dma_cap_set(DMA_PRIVATE, tdma->dma_dev.cap_mask);
dma_cap_set(DMA_CYCLIC, tdma->dma_dev.cap_mask);
+ dma_cap_set(DMA_MEMCPY, tdma->dma_dev.cap_mask);

tdma->dma_dev.dev = &pdev->dev;
tdma->dma_dev.device_alloc_chan_resources =
@@ -749,14 +816,18 @@ static int tegra_adma_probe(struct platform_device *pdev)
tegra_adma_free_chan_resources;
tdma->dma_dev.device_issue_pending = tegra_adma_issue_pending;
tdma->dma_dev.device_prep_dma_cyclic = tegra_adma_prep_dma_cyclic;
+ tdma->dma_dev.device_prep_dma_memcpy = tegra_adma_prep_dma_memcpy;
tdma->dma_dev.device_config = tegra_adma_slave_config;
tdma->dma_dev.device_tx_status = tegra_adma_tx_status;
tdma->dma_dev.device_terminate_all = tegra_adma_terminate_all;
tdma->dma_dev.src_addr_widths = BIT(DMA_SLAVE_BUSWIDTH_4_BYTES);
tdma->dma_dev.dst_addr_widths = BIT(DMA_SLAVE_BUSWIDTH_4_BYTES);
- tdma->dma_dev.directions = BIT(DMA_DEV_TO_MEM) | BIT(DMA_MEM_TO_DEV);
+ tdma->dma_dev.directions = BIT(DMA_DEV_TO_MEM) | BIT(DMA_MEM_TO_DEV) |
+ BIT(DMA_MEM_TO_MEM);
tdma->dma_dev.residue_granularity = DMA_RESIDUE_GRANULARITY_SEGMENT;

+ tdma->dma_dev.copy_align = DMAENGINE_ALIGN_4_BYTES;
+
ret = dma_async_device_register(&tdma->dma_dev);
if (ret < 0) {
dev_err(&pdev->dev, "ADMA registration failed: %d\n", ret);
--
2.1.4