[PATCH 2/2] dmaengine: ti: k3-udma: Add support for burst_size configuration for mem2mem

From: Peter Ujfalusi
Date: Mon Dec 14 2020 - 03:14:27 EST

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The UDMA and BCDMA can provide higher throughput if the burst_size of the
channel is changed from it's default (which is 64 bytes) for Ultra-high
and high capacity channels.

This performance benefit is even more visible when the buffers are aligned
with the burst_size configuration.

The am654 does not have a way to change the burst size, but it is using
64 bytes burst, so increasing the copy_align from 8 bytes to 64 (and
clients taking that into account) can increase the throughput as well.

Numbers gathered on j721e:
echo 8000000 > /sys/module/dmatest/parameters/test_buf_size
echo 2000 > /sys/module/dmatest/parameters/timeout
echo 50 > /sys/module/dmatest/parameters/iterations
echo 1 > /sys/module/dmatest/parameters/max_channels

Prior this patch: ~1.3 GB/s
After this patch: ~1.8 GB/s
with 1 byte alignment: ~1.7 GB/s

Signed-off-by: Peter Ujfalusi <peter.ujfalusi@xxxxxx>
---
drivers/dma/ti/k3-udma.c | 115 +++++++++++++++++++++++++++++++++++++--
1 file changed, 110 insertions(+), 5 deletions(-)

diff --git a/drivers/dma/ti/k3-udma.c b/drivers/dma/ti/k3-udma.c
index 87157cbae1b8..54e4ccb1b37e 100644
--- a/drivers/dma/ti/k3-udma.c
+++ b/drivers/dma/ti/k3-udma.c
@@ -121,6 +121,11 @@ struct udma_oes_offsets {
#define UDMA_FLAG_PDMA_ACC32 BIT(0)
#define UDMA_FLAG_PDMA_BURST BIT(1)
#define UDMA_FLAG_TDTYPE BIT(2)
+#define UDMA_FLAG_BURST_SIZE BIT(3)
+#define UDMA_FLAGS_J7_CLASS (UDMA_FLAG_PDMA_ACC32 | \
+ UDMA_FLAG_PDMA_BURST | \
+ UDMA_FLAG_TDTYPE | \
+ UDMA_FLAG_BURST_SIZE)

struct udma_match_data {
enum k3_dma_type type;
@@ -128,6 +133,7 @@ struct udma_match_data {
bool enable_memcpy_support;
u32 flags;
u32 statictr_z_mask;
+ u8 burst_size[3];
};

struct udma_soc_data {
@@ -436,6 +442,18 @@ static void k3_configure_chan_coherency(struct dma_chan *chan, u32 asel)
}
}

+static u8 udma_get_chan_tpl_index(struct udma_tpl *tpl_map, int chan_id)
+{
+ int i;
+
+ for (i = 0; i < tpl_map->levels; i++) {
+ if (chan_id >= tpl_map->start_idx[i])
+ return i;
+ }
+
+ return 0;
+}
+
static void udma_reset_uchan(struct udma_chan *uc)
{
memset(&uc->config, 0, sizeof(uc->config));
@@ -1811,6 +1829,7 @@ static int udma_tisci_m2m_channel_config(struct udma_chan *uc)
const struct ti_sci_rm_udmap_ops *tisci_ops = tisci_rm->tisci_udmap_ops;
struct udma_tchan *tchan = uc->tchan;
struct udma_rchan *rchan = uc->rchan;
+ u8 burst_size = 0;
int ret = 0;

/* Non synchronized - mem to mem type of transfer */
@@ -1818,6 +1837,12 @@ static int udma_tisci_m2m_channel_config(struct udma_chan *uc)
struct ti_sci_msg_rm_udmap_tx_ch_cfg req_tx = { 0 };
struct ti_sci_msg_rm_udmap_rx_ch_cfg req_rx = { 0 };

+ if (ud->match_data->flags & UDMA_FLAG_BURST_SIZE) {
+ u8 tpl = udma_get_chan_tpl_index(&ud->tchan_tpl, tchan->id);
+
+ burst_size = ud->match_data->burst_size[tpl];
+ }
+
req_tx.valid_params = TISCI_UDMA_TCHAN_VALID_PARAMS;
req_tx.nav_id = tisci_rm->tisci_dev_id;
req_tx.index = tchan->id;
@@ -1825,6 +1850,10 @@ static int udma_tisci_m2m_channel_config(struct udma_chan *uc)
req_tx.tx_fetch_size = sizeof(struct cppi5_desc_hdr_t) >> 2;
req_tx.txcq_qnum = tc_ring;
req_tx.tx_atype = ud->atype;
+ if (burst_size) {
+ req_tx.valid_params |= TI_SCI_MSG_VALUE_RM_UDMAP_CH_BURST_SIZE_VALID;
+ req_tx.tx_burst_size = burst_size;
+ }

ret = tisci_ops->tx_ch_cfg(tisci_rm->tisci, &req_tx);
if (ret) {
@@ -1839,6 +1868,10 @@ static int udma_tisci_m2m_channel_config(struct udma_chan *uc)
req_rx.rxcq_qnum = tc_ring;
req_rx.rx_chan_type = TI_SCI_RM_UDMAP_CHAN_TYPE_3RDP_BCOPY_PBRR;
req_rx.rx_atype = ud->atype;
+ if (burst_size) {
+ req_rx.valid_params |= TI_SCI_MSG_VALUE_RM_UDMAP_CH_BURST_SIZE_VALID;
+ req_rx.rx_burst_size = burst_size;
+ }

ret = tisci_ops->rx_ch_cfg(tisci_rm->tisci, &req_rx);
if (ret)
@@ -1854,12 +1887,23 @@ static int bcdma_tisci_m2m_channel_config(struct udma_chan *uc)
const struct ti_sci_rm_udmap_ops *tisci_ops = tisci_rm->tisci_udmap_ops;
struct ti_sci_msg_rm_udmap_tx_ch_cfg req_tx = { 0 };
struct udma_bchan *bchan = uc->bchan;
+ u8 burst_size = 0;
int ret = 0;

+ if (ud->match_data->flags & UDMA_FLAG_BURST_SIZE) {
+ u8 tpl = udma_get_chan_tpl_index(&ud->bchan_tpl, bchan->id);
+
+ burst_size = ud->match_data->burst_size[tpl];
+ }
+
req_tx.valid_params = TISCI_BCDMA_BCHAN_VALID_PARAMS;
req_tx.nav_id = tisci_rm->tisci_dev_id;
req_tx.extended_ch_type = TI_SCI_RM_BCDMA_EXTENDED_CH_TYPE_BCHAN;
req_tx.index = bchan->id;
+ if (burst_size) {
+ req_tx.valid_params |= TI_SCI_MSG_VALUE_RM_UDMAP_CH_BURST_SIZE_VALID;
+ req_tx.tx_burst_size = burst_size;
+ }

ret = tisci_ops->tx_ch_cfg(tisci_rm->tisci, &req_tx);
if (ret)
@@ -4167,6 +4211,11 @@ static struct udma_match_data am654_main_data = {
.psil_base = 0x1000,
.enable_memcpy_support = true,
.statictr_z_mask = GENMASK(11, 0),
+ .burst_size = {
+ TI_SCI_RM_UDMAP_CHAN_BURST_SIZE_64_BYTES, /* Normal Channels */
+ TI_SCI_RM_UDMAP_CHAN_BURST_SIZE_64_BYTES, /* H Channels */
+ 0, /* No UH Channels */
+ },
};

static struct udma_match_data am654_mcu_data = {
@@ -4174,38 +4223,63 @@ static struct udma_match_data am654_mcu_data = {
.psil_base = 0x6000,
.enable_memcpy_support = false,
.statictr_z_mask = GENMASK(11, 0),
+ .burst_size = {
+ TI_SCI_RM_UDMAP_CHAN_BURST_SIZE_64_BYTES, /* Normal Channels */
+ TI_SCI_RM_UDMAP_CHAN_BURST_SIZE_64_BYTES, /* H Channels */
+ 0, /* No UH Channels */
+ },
};

static struct udma_match_data j721e_main_data = {
.type = DMA_TYPE_UDMA,
.psil_base = 0x1000,
.enable_memcpy_support = true,
- .flags = UDMA_FLAG_PDMA_ACC32 | UDMA_FLAG_PDMA_BURST | UDMA_FLAG_TDTYPE,
+ .flags = UDMA_FLAGS_J7_CLASS,
.statictr_z_mask = GENMASK(23, 0),
+ .burst_size = {
+ TI_SCI_RM_UDMAP_CHAN_BURST_SIZE_64_BYTES, /* Normal Channels */
+ TI_SCI_RM_UDMAP_CHAN_BURST_SIZE_256_BYTES, /* H Channels */
+ TI_SCI_RM_UDMAP_CHAN_BURST_SIZE_256_BYTES, /* UH Channels */
+ },
};

static struct udma_match_data j721e_mcu_data = {
.type = DMA_TYPE_UDMA,
.psil_base = 0x6000,
.enable_memcpy_support = false, /* MEM_TO_MEM is slow via MCU UDMA */
- .flags = UDMA_FLAG_PDMA_ACC32 | UDMA_FLAG_PDMA_BURST | UDMA_FLAG_TDTYPE,
+ .flags = UDMA_FLAGS_J7_CLASS,
.statictr_z_mask = GENMASK(23, 0),
+ .burst_size = {
+ TI_SCI_RM_UDMAP_CHAN_BURST_SIZE_64_BYTES, /* Normal Channels */
+ TI_SCI_RM_UDMAP_CHAN_BURST_SIZE_128_BYTES, /* H Channels */
+ 0, /* No UH Channels */
+ },
};

static struct udma_match_data am64_bcdma_data = {
.type = DMA_TYPE_BCDMA,
.psil_base = 0x2000, /* for tchan and rchan, not applicable to bchan */
.enable_memcpy_support = true, /* Supported via bchan */
- .flags = UDMA_FLAG_PDMA_ACC32 | UDMA_FLAG_PDMA_BURST | UDMA_FLAG_TDTYPE,
+ .flags = UDMA_FLAGS_J7_CLASS,
.statictr_z_mask = GENMASK(23, 0),
+ .burst_size = {
+ TI_SCI_RM_UDMAP_CHAN_BURST_SIZE_64_BYTES, /* Normal Channels */
+ 0, /* No H Channels */
+ 0, /* No UH Channels */
+ },
};

static struct udma_match_data am64_pktdma_data = {
.type = DMA_TYPE_PKTDMA,
.psil_base = 0x1000,
.enable_memcpy_support = false, /* PKTDMA does not support MEM_TO_MEM */
- .flags = UDMA_FLAG_PDMA_ACC32 | UDMA_FLAG_PDMA_BURST | UDMA_FLAG_TDTYPE,
+ .flags = UDMA_FLAGS_J7_CLASS,
.statictr_z_mask = GENMASK(23, 0),
+ .burst_size = {
+ TI_SCI_RM_UDMAP_CHAN_BURST_SIZE_64_BYTES, /* Normal Channels */
+ 0, /* No H Channels */
+ 0, /* No UH Channels */
+ },
};

static const struct of_device_id udma_of_match[] = {
@@ -5045,6 +5119,35 @@ static void udma_dbg_summary_show(struct seq_file *s,
}
#endif /* CONFIG_DEBUG_FS */

+static enum dmaengine_alignment udma_get_copy_align(struct udma_dev *ud)
+{
+ const struct udma_match_data *match_data = ud->match_data;
+ u8 tpl;
+
+ if (!match_data->enable_memcpy_support)
+ return DMAENGINE_ALIGN_8_BYTES;
+
+ /* Get the highest TPL level the device supports for memcpy */
+ if (ud->bchan_cnt) {
+ tpl = udma_get_chan_tpl_index(&ud->bchan_tpl, 0);
+ } else if (ud->tchan_cnt) {
+ tpl = udma_get_chan_tpl_index(&ud->tchan_tpl, 0);
+ } else {
+ return DMAENGINE_ALIGN_8_BYTES;
+ }
+
+ switch (match_data->burst_size[tpl]) {
+ case TI_SCI_RM_UDMAP_CHAN_BURST_SIZE_256_BYTES:
+ return DMAENGINE_ALIGN_256_BYTES;
+ case TI_SCI_RM_UDMAP_CHAN_BURST_SIZE_128_BYTES:
+ return DMAENGINE_ALIGN_128_BYTES;
+ case TI_SCI_RM_UDMAP_CHAN_BURST_SIZE_64_BYTES:
+ fallthrough;
+ default:
+ return DMAENGINE_ALIGN_64_BYTES;
+ }
+}
+
#define TI_UDMAC_BUSWIDTHS (BIT(DMA_SLAVE_BUSWIDTH_1_BYTE) | \
BIT(DMA_SLAVE_BUSWIDTH_2_BYTES) | \
BIT(DMA_SLAVE_BUSWIDTH_3_BYTES) | \
@@ -5201,7 +5304,6 @@ static int udma_probe(struct platform_device *pdev)
ud->ddev.dst_addr_widths = TI_UDMAC_BUSWIDTHS;
ud->ddev.directions = BIT(DMA_DEV_TO_MEM) | BIT(DMA_MEM_TO_DEV);
ud->ddev.residue_granularity = DMA_RESIDUE_GRANULARITY_BURST;
- ud->ddev.copy_align = DMAENGINE_ALIGN_8_BYTES;
ud->ddev.desc_metadata_modes = DESC_METADATA_CLIENT |
DESC_METADATA_ENGINE;
if (ud->match_data->enable_memcpy_support &&
@@ -5283,6 +5385,9 @@ static int udma_probe(struct platform_device *pdev)
INIT_DELAYED_WORK(&uc->tx_drain.work, udma_check_tx_completion);
}

+ /* Configure the copy_align to the maximum burst size the device supports */
+ ud->ddev.copy_align = udma_get_copy_align(ud);
+
ret = dma_async_device_register(&ud->ddev);
if (ret) {
dev_err(dev, "failed to register slave DMA engine: %d\n", ret);
--
Peter

Texas Instruments Finland Oy, Porkkalankatu 22, 00180 Helsinki.
Y-tunnus/Business ID: 0615521-4. Kotipaikka/Domicile: Helsinki

Next message: Stefano Garzarella: "Re: [PATCH net-next v3 0/4] vsock: Add flags field in the vsock address"
Previous message: Peter Ujfalusi: "[PATCH 0/2] dmaengine: ti: k3-udma: memcpy throughput improvement"
In reply to: Peter Ujfalusi: "[PATCH 1/2] dmaengine: Extend the dmaengine_alignment for 128 and 256 bytes"
Messages sorted by: [ date ] [ thread ] [ subject ] [ author ]