[PATCH v4 5/5] r8169: Coalesce mac ocp commands for rtl_hw_init_8125 to reduce spinlocks

From: Mirsad Goran Todorovac
Date: Sun Oct 29 2023 - 07:14:20 EST


Repeated calls to r8168_mac_ocp_write() and r8168_mac_ocp_modify() in
the init sequence of the 8125 involve implicit spin_lock_irqsave() and
spin_unlock_irqrestore() on each invocation.

Coalesced with the corresponding helpers r8168_mac_ocp_write_seq() and
r8168_mac_ocp_modify_seq() into sequential write or modidy with a sinqle lock/unlock,
these calls reduce overall lock contention.

Fixes: f1bce4ad2f1ce ("r8169: add support for RTL8125")
Cc: Heiner Kallweit <hkallweit1@xxxxxxxxx>
Cc: Marco Elver <elver@xxxxxxxxxx>
Cc: nic_swsd@xxxxxxxxxxx
Cc: "David S. Miller" <davem@xxxxxxxxxxxxx>
Cc: Eric Dumazet <edumazet@xxxxxxxxxx>
Cc: Jakub Kicinski <kuba@xxxxxxxxxx>
Cc: Paolo Abeni <pabeni@xxxxxxxxxx>
Cc: netdev@xxxxxxxxxxxxxxx
Cc: linux-kernel@xxxxxxxxxxxxxxx
Link: https://lore.kernel.org/lkml/20231028005153.2180411-1-mirsad.todorovac@xxxxxxxxxxxx/
Link: https://lore.kernel.org/lkml/20231028110459.2644926-1-mirsad.todorovac@xxxxxxxxxxxx/
Signed-off-by: Mirsad Goran Todorovac <mirsad.todorovac@xxxxxxxxxxxx>
---
v4:
fixed complaints as advised by Heiner and checkpatch.pl.
split the patch into five sections to be more easily manipulated and reviewed
introduced r8168_mac_ocp_write_seq()
applied coalescing of mac ocp writes/modifies for 8168H, 8125 and 8125B

v3:
removed register/mask pair array sentinels, so using ARRAY_SIZE().
avoided duplication of RTL_W32() call code as advised by Heiner.

drivers/net/ethernet/realtek/r8169_main.c | 10 +++++++---
1 file changed, 7 insertions(+), 3 deletions(-)

diff --git a/drivers/net/ethernet/realtek/r8169_main.c b/drivers/net/ethernet/realtek/r8169_main.c
index dd65e0384ab3..8dce08d90367 100644
--- a/drivers/net/ethernet/realtek/r8169_main.c
+++ b/drivers/net/ethernet/realtek/r8169_main.c
@@ -5070,6 +5070,12 @@ static void rtl_hw_init_8168g(struct rtl8169_private *tp)

static void rtl_hw_init_8125(struct rtl8169_private *tp)
{
+ static const struct e_info_regdata hw_init_8125_1[] = {
+ { 0xc0aa, 0x07d0 },
+ { 0xc0a6, 0x0150 },
+ { 0xc01e, 0x5555 },
+ };
+
rtl_enable_rxdvgate(tp);

RTL_W8(tp, ChipCmd, RTL_R8(tp, ChipCmd) & ~(CmdTxEnb | CmdRxEnb));
@@ -5079,9 +5085,7 @@ static void rtl_hw_init_8125(struct rtl8169_private *tp)
r8168_mac_ocp_modify(tp, 0xe8de, BIT(14), 0);
r8168g_wait_ll_share_fifo_ready(tp);

- r8168_mac_ocp_write(tp, 0xc0aa, 0x07d0);
- r8168_mac_ocp_write(tp, 0xc0a6, 0x0150);
- r8168_mac_ocp_write(tp, 0xc01e, 0x5555);
+ r8168_mac_ocp_write_seq(tp, hw_init_8125_1);
r8168g_wait_ll_share_fifo_ready(tp);
}

--
2.34.1