Commit b6ab4b01 authored by Michael Chan's avatar Michael Chan Committed by David S. Miller

bnxt_en: Separate bnxt_{rx|tx}_ring_info structs from bnxt_napi struct.

Currently, an rx and a tx ring are always paired with a completion ring.
We want to restructure it so that it is possible to have a dedicated
completion ring for tx or rx only.

The bnxt hardware uses a completion ring for rx and tx events.  The driver
has to process the completion ring entries sequentially for the rx and tx
events.  Using a dedicated completion ring for rx only or tx only has these
benefits:

1. A burst of rx packets can cause delay in processing tx events if the
completion ring is shared.  If tx queue is stopped by BQL, this can cause
delay in re-starting the tx queue.

2. A completion ring is sized according to the rx and tx ring size rounded
up to the nearest power of 2.  When the completion ring is shared, it is
sized by adding the rx and tx ring sizes and then rounded to the next power
of 2, often with a lot of wasted space.

3. Using dedicated completion ring, we can adjust the tx and rx coalescing
parameters independently for rx and tx.

The first step is to separate the rx and tx ring structures from the
bnxt_napi struct.

In this patch, an rx ring and a tx ring will point to the same bnxt_napi
struct to share the same completion ring.  No change in ring assignment
and mapping yet.
Signed-off-by: default avatarMichael Chan <mchan@broadcom.com>
Signed-off-by: default avatarDavid S. Miller <davem@davemloft.net>
parent 9f554590
This diff is collapsed.
...@@ -528,6 +528,7 @@ struct tx_push_bd { ...@@ -528,6 +528,7 @@ struct tx_push_bd {
}; };
struct bnxt_tx_ring_info { struct bnxt_tx_ring_info {
struct bnxt_napi *bnapi;
u16 tx_prod; u16 tx_prod;
u16 tx_cons; u16 tx_cons;
void __iomem *tx_doorbell; void __iomem *tx_doorbell;
...@@ -558,6 +559,7 @@ struct bnxt_tpa_info { ...@@ -558,6 +559,7 @@ struct bnxt_tpa_info {
}; };
struct bnxt_rx_ring_info { struct bnxt_rx_ring_info {
struct bnxt_napi *bnapi;
u16 rx_prod; u16 rx_prod;
u16 rx_agg_prod; u16 rx_agg_prod;
u16 rx_sw_agg_prod; u16 rx_sw_agg_prod;
...@@ -604,8 +606,8 @@ struct bnxt_napi { ...@@ -604,8 +606,8 @@ struct bnxt_napi {
int index; int index;
struct bnxt_cp_ring_info cp_ring; struct bnxt_cp_ring_info cp_ring;
struct bnxt_rx_ring_info rx_ring; struct bnxt_rx_ring_info *rx_ring;
struct bnxt_tx_ring_info tx_ring; struct bnxt_tx_ring_info *tx_ring;
#ifdef CONFIG_NET_RX_BUSY_POLL #ifdef CONFIG_NET_RX_BUSY_POLL
atomic_t poll_state; atomic_t poll_state;
...@@ -884,6 +886,9 @@ struct bnxt { ...@@ -884,6 +886,9 @@ struct bnxt {
struct bnxt_napi **bnapi; struct bnxt_napi **bnapi;
struct bnxt_rx_ring_info *rx_ring;
struct bnxt_tx_ring_info *tx_ring;
u32 rx_buf_size; u32 rx_buf_size;
u32 rx_buf_use_size; /* useable size */ u32 rx_buf_use_size; /* useable size */
u32 rx_ring_size; u32 rx_ring_size;
......
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