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From:   Mirsad Goran Todorovac <mirsad.todorovac@alu.unizg.hr>
To:     Jason Gunthorpe <jgg@ziepe.ca>, Joerg Roedel <jroedel@suse.de>,
        Lu Baolu <baolu.lu@linux.intel.com>, iommu@lists.linux.dev,
        linux-kernel@vger.kernel.org, netdev@vger.kernel.org
Cc:     Joerg Roedel <joro@8bytes.org>, Will Deacon <will@kernel.org>,
        Robin Murphy <robin.murphy@arm.com>,
        Heiner Kallweit <hkallweit1@gmail.com>, nic_swsd@realtek.com,
        "David S. Miller" <davem@davemloft.net>,
        Eric Dumazet <edumazet@google.com>,
        Jakub Kicinski <kuba@kernel.org>,
        Paolo Abeni <pabeni@redhat.com>,
        Mirsad Goran Todorovac <mirsad.todorovac@alu.unizg.hr>,
        Marco Elver <elver@google.com>
Subject: [PATCH v5 7/7] r8169: Coalesce mac ocp write and modify for rtl_hw_init_8125 to reduce spinlock contention
Date:   Sun, 29 Oct 2023 19:36:07 +0100
Message-Id: <20231029183600.451694-7-mirsad.todorovac@alu.unizg.hr>
In-Reply-To: <20231029183600.451694-1-mirsad.todorovac@alu.unizg.hr>
References: <20231029183600.451694-1-mirsad.todorovac@alu.unizg.hr>
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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
pair of spin_lock_irqsave() and spin_unlock_irqrestore(), these calls
reduce overall lock contention.

Fixes: f1bce4ad2f1ce ("r8169: add support for RTL8125")
Cc: Heiner Kallweit <hkallweit1@gmail.com>
Cc: Marco Elver <elver@google.com>
Cc: nic_swsd@realtek.com
Cc: "David S. Miller" <davem@davemloft.net>
Cc: Eric Dumazet <edumazet@google.com>
Cc: Jakub Kicinski <kuba@kernel.org>
Cc: Paolo Abeni <pabeni@redhat.com>
Cc: netdev@vger.kernel.org
Cc: linux-kernel@vger.kernel.org
Link: https://lore.kernel.org/lkml/20231028005153.2180411-1-mirsad.todorovac@alu.unizg.hr/
Link: https://lore.kernel.org/lkml/20231028110459.2644926-1-mirsad.todorovac@alu.unizg.hr/
Signed-off-by: Mirsad Goran Todorovac <mirsad.todorovac@alu.unizg.hr>
---
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 0778cd0ba2e0..76f0f1e13909 100644
--- a/drivers/net/ethernet/realtek/r8169_main.c
+++ b/drivers/net/ethernet/realtek/r8169_main.c
@@ -5089,6 +5089,12 @@ 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));
@@ -5098,9 +5104,7 @@ 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