intel drivers: repair missing flush operations

after review of all intel drivers, found several instances where
drivers had the incorrect pattern of:
memory mapped write();
delay();

which should always be:
memory mapped write();
write flush(); /* aka memory mapped read */
delay();

explanation:
The reason for including the flush is that writes can be held
(posted) in PCI/PCIe bridges, but the read always has to complete
synchronously and therefore has to flush all pending writes to a
device.  If a write is held and followed by a delay, the delay
means nothing because the write may not have reached hardware
(maybe even not until the next read)

Signed-off-by: Jesse Brandeburg <jesse.brandeburg@intel.com>
Tested-by:  Aaron Brown <aaron.f.brown@intel.com>
Signed-off-by: Jeff Kirsher <jeffrey.t.kirsher@intel.com>

5 files changed, 18 insertions, 0 deletions

diff --git a/drivers/net/e1000e/es2lan.c b/drivers/net/e1000e/es2lan.c
index c0ecb2d9fdb..e4f42257c24 100644
--- a/drivers/net/e1000e/es2lan.c
+++ b/drivers/net/e1000e/es2lan.c
@@ -1313,6 +1313,7 @@ static s32 e1000_read_kmrn_reg_80003es2lan(struct e1000_hw *hw, u32 offset,
 	kmrnctrlsta = ((offset << E1000_KMRNCTRLSTA_OFFSET_SHIFT) &
 	               E1000_KMRNCTRLSTA_OFFSET) | E1000_KMRNCTRLSTA_REN;
 	ew32(KMRNCTRLSTA, kmrnctrlsta);
+	e1e_flush();
 
 	udelay(2);
 
@@ -1347,6 +1348,7 @@ static s32 e1000_write_kmrn_reg_80003es2lan(struct e1000_hw *hw, u32 offset,
 	kmrnctrlsta = ((offset << E1000_KMRNCTRLSTA_OFFSET_SHIFT) &
 	               E1000_KMRNCTRLSTA_OFFSET) | data;
 	ew32(KMRNCTRLSTA, kmrnctrlsta);
+	e1e_flush();
 
 	udelay(2);
 
diff --git a/drivers/net/e1000e/ethtool.c b/drivers/net/e1000e/ethtool.c
index cb1a3623253..72756e4e644 100644
--- a/drivers/net/e1000e/ethtool.c
+++ b/drivers/net/e1000e/ethtool.c
@@ -964,6 +964,7 @@ static int e1000_intr_test(struct e1000_adapter *adapter, u64 *data)
 
 	/* Disable all the interrupts */
 	ew32(IMC, 0xFFFFFFFF);
+	e1e_flush();
 	usleep_range(10000, 20000);
 
 	/* Test each interrupt */
@@ -996,6 +997,7 @@ static int e1000_intr_test(struct e1000_adapter *adapter, u64 *data)
 			adapter->test_icr = 0;
 			ew32(IMC, mask);
 			ew32(ICS, mask);
+			e1e_flush();
 			usleep_range(10000, 20000);
 
 			if (adapter->test_icr & mask) {
@@ -1014,6 +1016,7 @@ static int e1000_intr_test(struct e1000_adapter *adapter, u64 *data)
 		adapter->test_icr = 0;
 		ew32(IMS, mask);
 		ew32(ICS, mask);
+		e1e_flush();
 		usleep_range(10000, 20000);
 
 		if (!(adapter->test_icr & mask)) {
@@ -1032,6 +1035,7 @@ static int e1000_intr_test(struct e1000_adapter *adapter, u64 *data)
 			adapter->test_icr = 0;
 			ew32(IMC, ~mask & 0x00007FFF);
 			ew32(ICS, ~mask & 0x00007FFF);
+			e1e_flush();
 			usleep_range(10000, 20000);
 
 			if (adapter->test_icr) {
@@ -1043,6 +1047,7 @@ static int e1000_intr_test(struct e1000_adapter *adapter, u64 *data)
 
 	/* Disable all the interrupts */
 	ew32(IMC, 0xFFFFFFFF);
+	e1e_flush();
 	usleep_range(10000, 20000);
 
 	/* Unhook test interrupt handler */
@@ -1276,6 +1281,7 @@ static int e1000_integrated_phy_loopback(struct e1000_adapter *adapter)
 			     E1000_CTRL_FD);	 /* Force Duplex to FULL */
 
 		ew32(CTRL, ctrl_reg);
+		e1e_flush();
 		udelay(500);
 
 		return 0;
@@ -1418,6 +1424,7 @@ static int e1000_set_82571_fiber_loopback(struct e1000_adapter *adapter)
 	 */
 #define E1000_SERDES_LB_ON 0x410
 	ew32(SCTL, E1000_SERDES_LB_ON);
+	e1e_flush();
 	usleep_range(10000, 20000);
 
 	return 0;
@@ -1513,6 +1520,7 @@ static void e1000_loopback_cleanup(struct e1000_adapter *adapter)
 		    hw->phy.media_type == e1000_media_type_internal_serdes) {
 #define E1000_SERDES_LB_OFF 0x400
 			ew32(SCTL, E1000_SERDES_LB_OFF);
+			e1e_flush();
 			usleep_range(10000, 20000);
 			break;
 		}
@@ -1592,6 +1600,7 @@ static int e1000_run_loopback_test(struct e1000_adapter *adapter)
 				k = 0;
 		}
 		ew32(TDT, k);
+		e1e_flush();
 		msleep(200);
 		time = jiffies; /* set the start time for the receive */
 		good_cnt = 0;
diff --git a/drivers/net/e1000e/ich8lan.c b/drivers/net/e1000e/ich8lan.c
index c1752124f3c..f7a75c1531a 100644
--- a/drivers/net/e1000e/ich8lan.c
+++ b/drivers/net/e1000e/ich8lan.c
@@ -283,6 +283,7 @@ static void e1000_toggle_lanphypc_value_ich8lan(struct e1000_hw *hw)
 	ctrl |= E1000_CTRL_LANPHYPC_OVERRIDE;
 	ctrl &= ~E1000_CTRL_LANPHYPC_VALUE;
 	ew32(CTRL, ctrl);
+	e1e_flush();
 	udelay(10);
 	ctrl &= ~E1000_CTRL_LANPHYPC_OVERRIDE;
 	ew32(CTRL, ctrl);
@@ -1230,9 +1231,11 @@ s32 e1000_configure_k1_ich8lan(struct e1000_hw *hw, bool k1_enable)
 	ew32(CTRL, reg);
 
 	ew32(CTRL_EXT, ctrl_ext | E1000_CTRL_EXT_SPD_BYPS);
+	e1e_flush();
 	udelay(20);
 	ew32(CTRL, ctrl_reg);
 	ew32(CTRL_EXT, ctrl_ext);
+	e1e_flush();
 	udelay(20);
 
 out:
@@ -3090,6 +3093,7 @@ static s32 e1000_reset_hw_ich8lan(struct e1000_hw *hw)
 	ret_val = e1000_acquire_swflag_ich8lan(hw);
 	e_dbg("Issuing a global reset to ich8lan\n");
 	ew32(CTRL, (ctrl | E1000_CTRL_RST));
+	/* cannot issue a flush here because it hangs the hardware */
 	msleep(20);
 
 	if (!ret_val)
diff --git a/drivers/net/e1000e/lib.c b/drivers/net/e1000e/lib.c
index 65580b40594..7898a67d650 100644
--- a/drivers/net/e1000e/lib.c
+++ b/drivers/net/e1000e/lib.c
@@ -1986,6 +1986,7 @@ static s32 e1000_ready_nvm_eeprom(struct e1000_hw *hw)
 		/* Clear SK and CS */
 		eecd &= ~(E1000_EECD_CS | E1000_EECD_SK);
 		ew32(EECD, eecd);
+		e1e_flush();
 		udelay(1);
 
 		/*
diff --git a/drivers/net/e1000e/phy.c b/drivers/net/e1000e/phy.c
index 2a6ee13285b..8666476cb9b 100644
--- a/drivers/net/e1000e/phy.c
+++ b/drivers/net/e1000e/phy.c
@@ -537,6 +537,7 @@ static s32 __e1000_read_kmrn_reg(struct e1000_hw *hw, u32 offset, u16 *data,
 	kmrnctrlsta = ((offset << E1000_KMRNCTRLSTA_OFFSET_SHIFT) &
 		       E1000_KMRNCTRLSTA_OFFSET) | E1000_KMRNCTRLSTA_REN;
 	ew32(KMRNCTRLSTA, kmrnctrlsta);
+	e1e_flush();
 
 	udelay(2);
 
@@ -609,6 +610,7 @@ static s32 __e1000_write_kmrn_reg(struct e1000_hw *hw, u32 offset, u16 data,
 	kmrnctrlsta = ((offset << E1000_KMRNCTRLSTA_OFFSET_SHIFT) &
 		       E1000_KMRNCTRLSTA_OFFSET) | data;
 	ew32(KMRNCTRLSTA, kmrnctrlsta);
+	e1e_flush();
 
 	udelay(2);