[PATCH v3 net 0/2] net: ixgbe: Use new flag to disable Relaxed Ordering

From: Mao Wenan <redacted>

The new flag PCI_DEV_FLAGS_NO_RELAXED_ORDERING has been added
to indicate that Relaxed Ordering Attributes (RO) should not
be used for Transaction Layer Packets (TLP) targeted toward
these affected Root Port, it will clear the bit4 in the PCIe
Device Control register, so the PCIe device drivers could
query PCIe configuration space to determine if it can send
TLPs to Root Port with the Relaxed Ordering Attributes set.

The ixgbe driver could use this flag to determine if it can
send TLPs to Root Port with the Relaxed Ordering Attributes set.

v2: Simplify the original program according Alex's suggestion,
    remove the new ixgbe flag2 and only check the bit4 in the
    PCIe Device Control register. 

v3: Remove the code that clears the bits in DCA_T/RXCTRL, relaxed
    ordering should be enabled by the HW when the bus allow it.

Ding Tianhong (2):
  Revert commit 1a8b6d76dc5b ("net:add one common config...")
  net: ixgbe: Use new IXGBE_FLAG2_ROOT_NO_RELAXED_ORDERING flag

 arch/Kconfig                                    |  3 --
 arch/sparc/Kconfig                              |  1 -
 drivers/net/ethernet/intel/ixgbe/ixgbe_82598.c  | 37 ++++++++++++-------------
 drivers/net/ethernet/intel/ixgbe/ixgbe_common.c | 32 +++++++++++----------
 4 files changed, 35 insertions(+), 38 deletions(-)

-- 
1.8.3.1

The new flag PCI_DEV_FLAGS_NO_RELAXED_ORDERING has been added
to indicate that Relaxed Ordering Attributes (RO) should not
be used for Transaction Layer Packets (TLP) targeted toward
these affected Root Port, it will clear the bit4 in the PCIe
Device Control register, so the PCIe device drivers could
query PCIe configuration space to determine if it can send
TLPs to Root Port with the Relaxed Ordering Attributes set.

With this new flag  we don't need the config ARCH_WANT_RELAX_ORDER
to control the Relaxed Ordering Attributes for the ixgbe drivers
just like the commit 1a8b6d76dc5b ("net:add one common config...") did,
so revert this commit.

Signed-off-by: Ding Tianhong <redacted>
---
 arch/Kconfig                                    | 3 ---
 arch/sparc/Kconfig                              | 1 -
 drivers/net/ethernet/intel/ixgbe/ixgbe_common.c | 2 +-
 3 files changed, 1 insertion(+), 5 deletions(-)

diff --git a/arch/Kconfig b/arch/Kconfig
index 21d0089..00cfc63 100644
--- a/arch/Kconfig
+++ b/arch/Kconfig

@@ -928,9 +928,6 @@ config STRICT_MODULE_RWX
 	  and non-text memory will be made non-executable. This provides
 	  protection against certain security exploits (e.g. writing to text)
 
-config ARCH_WANT_RELAX_ORDER
-	bool
-
 config REFCOUNT_FULL
 	bool "Perform full reference count validation at the expense of speed"
 	help

diff --git a/arch/sparc/Kconfig b/arch/sparc/Kconfig
index a4a6261..987a575 100644
--- a/arch/sparc/Kconfig
+++ b/arch/sparc/Kconfig

@@ -44,7 +44,6 @@ config SPARC
 	select ARCH_HAS_SG_CHAIN
 	select CPU_NO_EFFICIENT_FFS
 	select LOCKDEP_SMALL if LOCKDEP
-	select ARCH_WANT_RELAX_ORDER
 
 config SPARC32
 	def_bool !64BIT

diff --git a/drivers/net/ethernet/intel/ixgbe/ixgbe_common.c b/drivers/net/ethernet/intel/ixgbe/ixgbe_common.c
index 4e35e70..d4933d2 100644
--- a/drivers/net/ethernet/intel/ixgbe/ixgbe_common.c
+++ b/drivers/net/ethernet/intel/ixgbe/ixgbe_common.c

@@ -350,7 +350,7 @@ s32 ixgbe_start_hw_gen2(struct ixgbe_hw *hw)
 	}
 	IXGBE_WRITE_FLUSH(hw);
 
-#ifndef CONFIG_ARCH_WANT_RELAX_ORDER
+#ifndef CONFIG_SPARC
 	/* Disable relaxed ordering */
 	for (i = 0; i < hw->mac.max_tx_queues; i++) {
 		u32 regval;

-- 
1.8.3.1

The ixgbe driver use the compile check to determine if it can
send TLPs to Root Port with the Relaxed Ordering Attribute set,
this is too inconvenient, now the new flag PCI_DEV_FLAGS_NO_RELAXED_ORDERING
has been added to the kernel and we could check the bit4 in the PCIe
Device Control register to determine whether we should use the Relaxed
Ordering Attributes or not, so use this new way in the ixgbe driver.

Signed-off-by: Ding Tianhong <redacted>
---
 drivers/net/ethernet/intel/ixgbe/ixgbe_82598.c  | 22 ----------------------
 drivers/net/ethernet/intel/ixgbe/ixgbe_common.c | 19 -------------------
 2 files changed, 41 deletions(-)

diff --git a/drivers/net/ethernet/intel/ixgbe/ixgbe_82598.c b/drivers/net/ethernet/intel/ixgbe/ixgbe_82598.c
index 523f9d0..8a32eb7 100644
--- a/drivers/net/ethernet/intel/ixgbe/ixgbe_82598.c
+++ b/drivers/net/ethernet/intel/ixgbe/ixgbe_82598.c

@@ -175,31 +175,9 @@ static s32 ixgbe_init_phy_ops_82598(struct ixgbe_hw *hw)
  **/
 static s32 ixgbe_start_hw_82598(struct ixgbe_hw *hw)
 {
-#ifndef CONFIG_SPARC
-	u32 regval;
-	u32 i;
-#endif
 	s32 ret_val;
 
 	ret_val = ixgbe_start_hw_generic(hw);
-
-#ifndef CONFIG_SPARC
-	/* Disable relaxed ordering */
-	for (i = 0; ((i < hw->mac.max_tx_queues) &&
-	     (i < IXGBE_DCA_MAX_QUEUES_82598)); i++) {
-		regval = IXGBE_READ_REG(hw, IXGBE_DCA_TXCTRL(i));
-		regval &= ~IXGBE_DCA_TXCTRL_DESC_WRO_EN;
-		IXGBE_WRITE_REG(hw, IXGBE_DCA_TXCTRL(i), regval);
-	}
-
-	for (i = 0; ((i < hw->mac.max_rx_queues) &&
-	     (i < IXGBE_DCA_MAX_QUEUES_82598)); i++) {
-		regval = IXGBE_READ_REG(hw, IXGBE_DCA_RXCTRL(i));
-		regval &= ~(IXGBE_DCA_RXCTRL_DATA_WRO_EN |
-			    IXGBE_DCA_RXCTRL_HEAD_WRO_EN);
-		IXGBE_WRITE_REG(hw, IXGBE_DCA_RXCTRL(i), regval);
-	}
-#endif
 	if (ret_val)
 		return ret_val;
 

diff --git a/drivers/net/ethernet/intel/ixgbe/ixgbe_common.c b/drivers/net/ethernet/intel/ixgbe/ixgbe_common.c
index d4933d2..96c324f 100644
--- a/drivers/net/ethernet/intel/ixgbe/ixgbe_common.c
+++ b/drivers/net/ethernet/intel/ixgbe/ixgbe_common.c

@@ -350,25 +350,6 @@ s32 ixgbe_start_hw_gen2(struct ixgbe_hw *hw)
 	}
 	IXGBE_WRITE_FLUSH(hw);
 
-#ifndef CONFIG_SPARC
-	/* Disable relaxed ordering */
-	for (i = 0; i < hw->mac.max_tx_queues; i++) {
-		u32 regval;
-
-		regval = IXGBE_READ_REG(hw, IXGBE_DCA_TXCTRL_82599(i));
-		regval &= ~IXGBE_DCA_TXCTRL_DESC_WRO_EN;
-		IXGBE_WRITE_REG(hw, IXGBE_DCA_TXCTRL_82599(i), regval);
-	}
-
-	for (i = 0; i < hw->mac.max_rx_queues; i++) {
-		u32 regval;
-
-		regval = IXGBE_READ_REG(hw, IXGBE_DCA_RXCTRL(i));
-		regval &= ~(IXGBE_DCA_RXCTRL_DATA_WRO_EN |
-			    IXGBE_DCA_RXCTRL_HEAD_WRO_EN);
-		IXGBE_WRITE_REG(hw, IXGBE_DCA_RXCTRL(i), regval);
-	}
-#endif
 	return 0;
 }
 

-- 
1.8.3.1

-----Original Message-----
From: linux-kernel-owner@vger.kernel.org [mailto:linux-kernel-
owner@vger.kernel.org] On Behalf Of Ding Tianhong
Sent: Thursday, August 17, 2017 11:21 PM
To: davem@davemloft.net; Kirsher, Jeffrey T <redacted>;
keescook@chromium.org; linux-kernel@vger.kernel.org;
sparclinux@vger.kernel.org; intel-wired-lan@lists.osuosl.org;
alexander.duyck@gmail.com; netdev@vger.kernel.org; linuxarm@huawei.com
Cc: Ding Tianhong <redacted>
Subject: [PATCH v3 net 2/2] net: ixgbe: Use new
PCI_DEV_FLAGS_NO_RELAXED_ORDERING flag

The ixgbe driver use the compile check to determine if it can
send TLPs to Root Port with the Relaxed Ordering Attribute set,
this is too inconvenient, now the new flag
PCI_DEV_FLAGS_NO_RELAXED_ORDERING
has been added to the kernel and we could check the bit4 in the PCIe
Device Control register to determine whether we should use the Relaxed
Ordering Attributes or not, so use this new way in the ixgbe driver.

Signed-off-by: Ding Tianhong <redacted>
---
drivers/net/ethernet/intel/ixgbe/ixgbe_82598.c  | 22 ---------------------
-
drivers/net/ethernet/intel/ixgbe/ixgbe_common.c | 19 -------------------
2 files changed, 41 deletions(-)

This change looks good to me for ixgbe.

Acked-by: Emil Tantilov <redacted>

Thanks,
Emil