[PATCH v2 RFC net-next 14/18] net: mvpp2: add BM protection underrun feature support

stefanc
2021-01-24T11:56:55Z

Feature double size of BPPI by decreasing number of pools from 16 to 8.
Increasing of BPPI size protect BM drop from BPPI underrun.
Underrun could occurred due to stress on DDR and as result slow buffer
transition from BPPE to BPPI.
New BPPI threshold recommended by spec is:
BPPI low threshold - 640 buffers
BPPI high threshold - 832 buffers
Supported only in PPv23.

Signed-off-by: Stefan Chulski <stefanc@marvell.com>
---
drivers/net/ethernet/marvell/mvpp2/mvpp2.h | 8 +++++
drivers/net/ethernet/marvell/mvpp2/mvpp2_main.c | 35 +++++++++++++++++++-
2 files changed, 42 insertions(+), 1 deletion(-)

diff --git a/drivers/net/ethernet/marvell/mvpp2/mvpp2.h b/drivers/net/ethernet/marvell/mvpp2/mvpp2.h
index feac64c..1db8245 100644
--- a/drivers/net/ethernet/marvell/mvpp2/mvpp2.h
+++ b/drivers/net/ethernet/marvell/mvpp2/mvpp2.h
@@ -324,6 +324,10 @@
#define MVPP2_BM_HIGH_THRESH_MASK 0x7f0000
#define MVPP2_BM_HIGH_THRESH_VALUE(val) ((val) << \
MVPP2_BM_HIGH_THRESH_OFFS)
+#define MVPP2_BM_BPPI_HIGH_THRESH 0x1E
+#define MVPP2_BM_BPPI_LOW_THRESH 0x1C
+#define MVPP23_BM_BPPI_HIGH_THRESH 0x34
+#define MVPP23_BM_BPPI_LOW_THRESH 0x28
#define MVPP2_BM_INTR_CAUSE_REG(pool) (0x6240 + ((pool) * 4))
#define MVPP2_BM_RELEASED_DELAY_MASK BIT(0)
#define MVPP2_BM_ALLOC_FAILED_MASK BIT(1)
@@ -352,6 +356,10 @@
#define MVPP2_OVERRUN_ETH_DROP 0x7000
#define MVPP2_CLS_ETH_DROP 0x7020

+#define MVPP22_BM_POOL_BASE_ADDR_HIGH_REG 0x6310
+#define MVPP22_BM_POOL_BASE_ADDR_HIGH_MASK 0xff
+#define MVPP23_BM_8POOL_MODE BIT(8)
+
/* Hit counters registers */
#define MVPP2_CTRS_IDX 0x7040
#define MVPP22_CTRS_TX_CTR(port, txq) ((txq) | ((port) << 3) | BIT(7))
diff --git a/drivers/net/ethernet/marvell/mvpp2/mvpp2_main.c b/drivers/net/ethernet/marvell/mvpp2/mvpp2_main.c
index 20157b5..da387dd2 100644
--- a/drivers/net/ethernet/marvell/mvpp2/mvpp2_main.c
+++ b/drivers/net/ethernet/marvell/mvpp2/mvpp2_main.c
@@ -70,6 +70,11 @@ enum mvpp2_bm_pool_log_num {
module_param(queue_mode, int, 0444);
MODULE_PARM_DESC(queue_mode, "Set queue_mode (single=0, multi=1)");

+static int bm_underrun_protect = 1;
+
+module_param(bm_underrun_protect, int, 0444);
+MODULE_PARM_DESC(bm_underrun_protect, "Set BM underrun protect feature (0-1), def=1");
+
/* Utility/helper methods */

void mvpp2_write(struct mvpp2 *priv, u32 offset, u32 data)
@@ -426,6 +431,21 @@ static int mvpp2_bm_pool_create(struct device *dev, struct mvpp2 *priv,

val = mvpp2_read(priv, MVPP2_BM_POOL_CTRL_REG(bm_pool->id));
val |= MVPP2_BM_START_MASK;
+
+ val &= ~MVPP2_BM_LOW_THRESH_MASK;
+ val &= ~MVPP2_BM_HIGH_THRESH_MASK;
+
+ /* Set 8 Pools BPPI threshold if BM underrun protection feature
+ * were enabled
+ */
+ if (priv->hw_version == MVPP23 && bm_underrun_protect) {
+ val |= MVPP2_BM_LOW_THRESH_VALUE(MVPP23_BM_BPPI_LOW_THRESH);
+ val |= MVPP2_BM_HIGH_THRESH_VALUE(MVPP23_BM_BPPI_HIGH_THRESH);
+ } else {
+ val |= MVPP2_BM_LOW_THRESH_VALUE(MVPP2_BM_BPPI_LOW_THRESH);
+ val |= MVPP2_BM_HIGH_THRESH_VALUE(MVPP2_BM_BPPI_HIGH_THRESH);
+ }
+
mvpp2_write(priv, MVPP2_BM_POOL_CTRL_REG(bm_pool->id), val);

bm_pool->size = size;
@@ -594,6 +614,16 @@ static int mvpp2_bm_pools_init(struct device *dev, struct mvpp2 *priv)
return err;
}

+/* Routine enable PPv23 8 pool mode */
+static void mvpp23_bm_set_8pool_mode(struct mvpp2 *priv)
+{
+ int val;
+
+ val = mvpp2_read(priv, MVPP22_BM_POOL_BASE_ADDR_HIGH_REG);
+ val |= MVPP23_BM_8POOL_MODE;
+ mvpp2_write(priv, MVPP22_BM_POOL_BASE_ADDR_HIGH_REG, val);
+}
+
static int mvpp2_bm_init(struct device *dev, struct mvpp2 *priv)
{
enum dma_data_direction dma_dir = DMA_FROM_DEVICE;
@@ -647,6 +677,9 @@ static int mvpp2_bm_init(struct device *dev, struct mvpp2 *priv)
if (!priv->bm_pools)
return -ENOMEM;

+ if (priv->hw_version == MVPP23 && bm_underrun_protect)
+ mvpp23_bm_set_8pool_mode(priv);
+
err = mvpp2_bm_pools_init(dev, priv);
if (err < 0)
return err;
@@ -6490,7 +6523,7 @@ static void mvpp2_mac_link_up(struct phylink_config *config,
val);
}

- if (tx_pause && port->priv->global_tx_fc) {
+ if (tx_pause && port->priv->global_tx_fc && bm_underrun_protect) {
port->tx_fc = true;
mvpp2_rxq_enable_fc(port);
if (port->priv->percpu_pools) {
--
1.9.1