From: Liron Himi <redacted>

Currently the HW is configured with only one pool which its buffer size may be larger than the rx-fifo-size.
In that situation, frame size larger than the fifo-size is gets dropped due to fifo overrun.
this is cause because the HW works in cut-through mode which waits to have in the fifo at least the amount of bytes as define in the smallest pool's buffer size.

This patch add a dummy pool which its buffer size is very small (smaller than 64B frame). this tricks the HW and any frame size is gets passed from the FIFO to the PP2.

Signed-off-by: Liron Himi <redacted>
---
 drivers/net/mvpp2/mrvl_ethdev.c | 71 ++++++++++++++++++++++++++-------  drivers/net/mvpp2/mrvl_ethdev.h |  2 +
 drivers/net/mvpp2/mrvl_qos.c    |  1 +
 3 files changed, 60 insertions(+), 14 deletions(-)

diff --git a/drivers/net/mvpp2/mrvl_ethdev.c b/drivers/net/mvpp2/mrvl_ethdev.c index 127861a82..1f9489d77 100644
--- a/drivers/net/mvpp2/mrvl_ethdev.c
+++ b/drivers/net/mvpp2/mrvl_ethdev.c

@@ -90,6 +90,8 @@ static int used_bpools[PP2_NUM_PKT_PROC] = {  static struct pp2_bpool *mrvl_port_to_bpool_lookup[RTE_MAX_ETHPORTS];
 static int mrvl_port_bpool_size[PP2_NUM_PKT_PROC][PP2_BPOOL_NUM_POOLS][RTE_MAX_LCORE];
 static uint64_t cookie_addr_high = MRVL_COOKIE_ADDR_INVALID;
+static int dummy_pool_id[PP2_NUM_PKT_PROC]; struct pp2_bpool
+*dummy_pool[PP2_NUM_PKT_PROC] = {0};

 struct mrvl_ifnames {
        const char *names[PP2_NUM_ETH_PPIO * PP2_NUM_PKT_PROC]; @@ -189,6 +191,19 @@ static struct {
        MRVL_XSTATS_TBL_ENTRY(tx_errors)
 };

+static inline int
+mrvl_reserve_bit(int *bitmap, int max)
+{
+       int n = sizeof(*bitmap) * 8 - __builtin_clz(*bitmap);
+
+       if (n >= max)
+               return -1;
+
+       *bitmap |= 1 << n;
+
+       return n;
+}
+
 /**
  * Initialize packet processor.
  *

@@ -199,6 +214,9 @@ static int
 mrvl_init_pp2(void)
 {
        struct pp2_init_params init_params;
+       struct pp2_bpool_params bpool_params;
+       char                    name[15];
+       int                     err, i;

        memset(&init_params, 0, sizeof(init_params));
        init_params.hif_reserved_map = MRVL_MUSDK_HIFS_RESERVED; @@ -207,7 +225,36 @@ mrvl_init_pp2(void)
        if (mrvl_cfg && mrvl_cfg->pp2_cfg.prs_udfs.num_udfs)
                memcpy(&init_params.prs_udfs, &mrvl_cfg->pp2_cfg.prs_udfs,
                       sizeof(struct pp2_parse_udfs));
-       return pp2_init(&init_params);
+       err = pp2_init(&init_params);
+       if (err != 0) {
+               MRVL_LOG(ERR, "PP2 init failed");
+               return -1;
+       }
+
+       memset(dummy_pool, 0, sizeof(dummy_pool));
+       for (i = 0; i < pp2_get_num_inst(); i++) {
+               dummy_pool_id[i] = mrvl_reserve_bit(&used_bpools[i],
+                                            PP2_BPOOL_NUM_POOLS);
+               if (dummy_pool_id[i] < 0) {
+                       MRVL_LOG(ERR, "Can't find free pool\n");
+                       return -1;
+               }
+
+               memset(name, 0, sizeof(name));
+               snprintf(name, sizeof(name), "pool-%d:%d", i, dummy_pool_id[i]);
+               memset(&bpool_params, 0, sizeof(bpool_params));
+               bpool_params.match = name;
+               bpool_params.buff_len = MRVL_PKT_OFFS;
+               bpool_params.dummy_short_pool = 1;
+               err = pp2_bpool_init(&bpool_params, &dummy_pool[i]);
+               if (err != 0 || !dummy_pool[i]) {
+                       MRVL_LOG(ERR, "BPool init failed!\n");
+                       used_bpools[i] &= ~(1 << dummy_pool_id[i]);
+                       return -1;