[PATCH v5 4/7] r8169: Coalesce mac ocp write and modify for 8168ep start to reduce spinlock contention

From: Mirsad Goran Todorovac
Date: Sun Oct 29 2023 - 14:43:35 EST


Repeated calls to r8168_mac_ocp_write() and r8168_mac_ocp_modify() in
the startup of RTL8168ep involve implicit spin_lock_irqsave() and
spin_unlock_irqrestore() on each invocation.

Coalesced with the corresponding helpers into r8168_mac_ocp_write_seq() and
r8168_mac_ocp_modify_seq() with a sinqle paired spin_lock_irqsave() and
spin_unlock_irqrestore(), these calls help reduce overall spinlock contention.

Fixes: ef712ede3541d ("r8169: add helper r8168_mac_ocp_modify")
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>
---
v5:
added unlocked primitives to allow mac ocs modify grouping
applied coalescing of mac ocp writes/modifies for 8168ep and 8117
some formatting fixes to please checkpatch.pl

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 29ee93b8b702..27016aaeb6a0 100644
--- a/drivers/net/ethernet/realtek/r8169_main.c
+++ b/drivers/net/ethernet/realtek/r8169_main.c
@@ -3326,6 +3326,12 @@ static void rtl_hw_start_8168ep_3(struct rtl8169_private *tp)
{ 0x1e, 0x0000, 0x2000 },
};

+ static const struct e_info_regmaskset e_info_8168ep_3_mod_1[] = {
+ { 0xd3e2, 0x0fff, 0x0271 },
+ { 0xd3e4, 0x00ff, 0x0000 },
+ { 0xe860, 0x0000, 0x0080 },
+ };
+
rtl_ephy_init(tp, e_info_8168ep_3);

rtl_hw_start_8168ep(tp);
@@ -3333,9 +3339,7 @@ static void rtl_hw_start_8168ep_3(struct rtl8169_private *tp)
RTL_W8(tp, DLLPR, RTL_R8(tp, DLLPR) & ~PFM_EN);
RTL_W8(tp, MISC_1, RTL_R8(tp, MISC_1) & ~PFM_D3COLD_EN);

- r8168_mac_ocp_modify(tp, 0xd3e2, 0x0fff, 0x0271);
- r8168_mac_ocp_modify(tp, 0xd3e4, 0x00ff, 0x0000);
- r8168_mac_ocp_modify(tp, 0xe860, 0x0000, 0x0080);
+ r8168_mac_ocp_modify_seq(tp, e_info_8168ep_3_mod_1);
}

static void rtl_hw_start_8117(struct rtl8169_private *tp)
--
2.34.1