Merge branch 'in_interrupt-cleanup-part-2'

Sebastian Andrzej Siewior says:

====================
in_interrupt() cleanup, part 2

in the discussion about preempt count consistency across kernel configurations:

  https://lore.kernel.org/r/20200914204209.256266093@linutronix.de/

Linus clearly requested that code in drivers and libraries which changes
behaviour based on execution context should either be split up so that
e.g. task context invocations and BH invocations have different interfaces
or if that's not possible the context information has to be provided by the
caller which knows in which context it is executing.

This includes conditional locking, allocation mode (GFP_*) decisions and
avoidance of code paths which might sleep.

In the long run, usage of 'preemptible, in_*irq etc.' should be banned from
driver code completely.

This is part two addressing remaining drivers except for orinoco-usb.
====================

Cherry picking only Ethernet changes.

Link: https://lore.kernel.org/r/20201027225454.3492351-1-bigeasy@linutronix.de
Signed-off-by: Jakub Kicinski <kuba@kernel.org>

4 files changed, 83 insertions, 66 deletions

diff --git a/drivers/net/ethernet/neterion/s2io.c b/drivers/net/ethernet/neterion/s2io.c
index d13d92bf7447..8f2f091bce89 100644
--- a/drivers/net/ethernet/neterion/s2io.c
+++ b/drivers/net/ethernet/neterion/s2io.c
@@ -1106,7 +1106,7 @@ static int s2io_print_pci_mode(struct s2io_nic *nic)
  *  '-1' on failure
  */
 
-static int init_tti(struct s2io_nic *nic, int link)
+static int init_tti(struct s2io_nic *nic, int link, bool may_sleep)
 {
 	struct XENA_dev_config __iomem *bar0 = nic->bar0;
 	register u64 val64 = 0;
@@ -1166,7 +1166,7 @@ static int init_tti(struct s2io_nic *nic, int link)
 
 		if (wait_for_cmd_complete(&bar0->tti_command_mem,
 					  TTI_CMD_MEM_STROBE_NEW_CMD,
-					  S2IO_BIT_RESET) != SUCCESS)
+					  S2IO_BIT_RESET, may_sleep) != SUCCESS)
 			return FAILURE;
 	}
 
@@ -1659,7 +1659,7 @@ static int init_nic(struct s2io_nic *nic)
 	 */
 
 	/* Initialize TTI */
-	if (SUCCESS != init_tti(nic, nic->last_link_state))
+	if (SUCCESS != init_tti(nic, nic->last_link_state, true))
 		return -ENODEV;
 
 	/* RTI Initialization */
@@ -3331,7 +3331,7 @@ static void s2io_updt_xpak_counter(struct net_device *dev)
  */
 
 static int wait_for_cmd_complete(void __iomem *addr, u64 busy_bit,
-				 int bit_state)
+				 int bit_state, bool may_sleep)
 {
 	int ret = FAILURE, cnt = 0, delay = 1;
 	u64 val64;
@@ -3353,7 +3353,7 @@ static int wait_for_cmd_complete(void __iomem *addr, u64 busy_bit,
 			}
 		}
 
-		if (in_interrupt())
+		if (!may_sleep)
 			mdelay(delay);
 		else
 			msleep(delay);
@@ -4877,8 +4877,7 @@ static struct net_device_stats *s2io_get_stats(struct net_device *dev)
  *  Return value:
  *  void.
  */
-
-static void s2io_set_multicast(struct net_device *dev)
+static void s2io_set_multicast(struct net_device *dev, bool may_sleep)
 {
 	int i, j, prev_cnt;
 	struct netdev_hw_addr *ha;
@@ -4903,7 +4902,7 @@ static void s2io_set_multicast(struct net_device *dev)
 		/* Wait till command completes */
 		wait_for_cmd_complete(&bar0->rmac_addr_cmd_mem,
 				      RMAC_ADDR_CMD_MEM_STROBE_CMD_EXECUTING,
-				      S2IO_BIT_RESET);
+				      S2IO_BIT_RESET, may_sleep);
 
 		sp->m_cast_flg = 1;
 		sp->all_multi_pos = config->max_mc_addr - 1;
@@ -4920,7 +4919,7 @@ static void s2io_set_multicast(struct net_device *dev)
 		/* Wait till command completes */
 		wait_for_cmd_complete(&bar0->rmac_addr_cmd_mem,
 				      RMAC_ADDR_CMD_MEM_STROBE_CMD_EXECUTING,
-				      S2IO_BIT_RESET);
+				      S2IO_BIT_RESET, may_sleep);
 
 		sp->m_cast_flg = 0;
 		sp->all_multi_pos = 0;
@@ -5000,7 +4999,7 @@ static void s2io_set_multicast(struct net_device *dev)
 			/* Wait for command completes */
 			if (wait_for_cmd_complete(&bar0->rmac_addr_cmd_mem,
 						  RMAC_ADDR_CMD_MEM_STROBE_CMD_EXECUTING,
-						  S2IO_BIT_RESET)) {
+						  S2IO_BIT_RESET, may_sleep)) {
 				DBG_PRINT(ERR_DBG,
 					  "%s: Adding Multicasts failed\n",
 					  dev->name);
@@ -5030,7 +5029,7 @@ static void s2io_set_multicast(struct net_device *dev)
 			/* Wait for command completes */
 			if (wait_for_cmd_complete(&bar0->rmac_addr_cmd_mem,
 						  RMAC_ADDR_CMD_MEM_STROBE_CMD_EXECUTING,
-						  S2IO_BIT_RESET)) {
+						  S2IO_BIT_RESET, may_sleep)) {
 				DBG_PRINT(ERR_DBG,
 					  "%s: Adding Multicasts failed\n",
 					  dev->name);
@@ -5041,6 +5040,12 @@ static void s2io_set_multicast(struct net_device *dev)
 	}
 }
 
+/* NDO wrapper for s2io_set_multicast */
+static void s2io_ndo_set_multicast(struct net_device *dev)
+{
+	s2io_set_multicast(dev, false);
+}
+
 /* read from CAM unicast & multicast addresses and store it in
  * def_mac_addr structure
  */
@@ -5127,7 +5132,7 @@ static int do_s2io_add_mac(struct s2io_nic *sp, u64 addr, int off)
 	/* Wait till command completes */
 	if (wait_for_cmd_complete(&bar0->rmac_addr_cmd_mem,
 				  RMAC_ADDR_CMD_MEM_STROBE_CMD_EXECUTING,
-				  S2IO_BIT_RESET)) {
+				  S2IO_BIT_RESET, true)) {
 		DBG_PRINT(INFO_DBG, "do_s2io_add_mac failed\n");
 		return FAILURE;
 	}
@@ -5171,7 +5176,7 @@ static u64 do_s2io_read_unicast_mc(struct s2io_nic *sp, int offset)
 	/* Wait till command completes */
 	if (wait_for_cmd_complete(&bar0->rmac_addr_cmd_mem,
 				  RMAC_ADDR_CMD_MEM_STROBE_CMD_EXECUTING,
-				  S2IO_BIT_RESET)) {
+				  S2IO_BIT_RESET, true)) {
 		DBG_PRINT(INFO_DBG, "do_s2io_read_unicast_mc failed\n");
 		return FAILURE;
 	}
@@ -7141,7 +7146,7 @@ static int s2io_card_up(struct s2io_nic *sp)
 	}
 
 	/* Setting its receive mode */
-	s2io_set_multicast(dev);
+	s2io_set_multicast(dev, true);
 
 	if (dev->features & NETIF_F_LRO) {
 		/* Initialize max aggregatable pkts per session based on MTU */
@@ -7447,7 +7452,7 @@ static void s2io_link(struct s2io_nic *sp, int link)
 	struct swStat *swstats = &sp->mac_control.stats_info->sw_stat;
 
 	if (link != sp->last_link_state) {
-		init_tti(sp, link);
+		init_tti(sp, link, false);
 		if (link == LINK_DOWN) {
 			DBG_PRINT(ERR_DBG, "%s: Link down\n", dev->name);
 			s2io_stop_all_tx_queue(sp);
@@ -7604,7 +7609,7 @@ static int rts_ds_steer(struct s2io_nic *nic, u8 ds_codepoint, u8 ring)
 
 	return wait_for_cmd_complete(&bar0->rts_ds_mem_ctrl,
 				     RTS_DS_MEM_CTRL_STROBE_CMD_BEING_EXECUTED,
-				     S2IO_BIT_RESET);
+				     S2IO_BIT_RESET, true);
 }
 
 static const struct net_device_ops s2io_netdev_ops = {
@@ -7613,7 +7618,7 @@ static const struct net_device_ops s2io_netdev_ops = {
 	.ndo_get_stats	        = s2io_get_stats,
 	.ndo_start_xmit    	= s2io_xmit,
 	.ndo_validate_addr	= eth_validate_addr,
-	.ndo_set_rx_mode	= s2io_set_multicast,
+	.ndo_set_rx_mode	= s2io_ndo_set_multicast,
 	.ndo_do_ioctl	   	= s2io_ioctl,
 	.ndo_set_mac_address    = s2io_set_mac_addr,
 	.ndo_change_mtu	   	= s2io_change_mtu,
@@ -7929,7 +7934,7 @@ s2io_init_nic(struct pci_dev *pdev, const struct pci_device_id *pre)
 	writeq(val64, &bar0->rmac_addr_cmd_mem);
 	wait_for_cmd_complete(&bar0->rmac_addr_cmd_mem,
 			      RMAC_ADDR_CMD_MEM_STROBE_CMD_EXECUTING,
-			      S2IO_BIT_RESET);
+			      S2IO_BIT_RESET, true);
 	tmp64 = readq(&bar0->rmac_addr_data0_mem);
 	mac_down = (u32)tmp64;
 	mac_up = (u32) (tmp64 >> 32);
diff --git a/drivers/net/ethernet/neterion/s2io.h b/drivers/net/ethernet/neterion/s2io.h
index 6fa3159a977f..5a6032212c19 100644
--- a/drivers/net/ethernet/neterion/s2io.h
+++ b/drivers/net/ethernet/neterion/s2io.h
@@ -1066,7 +1066,7 @@ static void tx_intr_handler(struct fifo_info *fifo_data);
 static void s2io_handle_errors(void * dev_id);
 
 static void s2io_tx_watchdog(struct net_device *dev, unsigned int txqueue);
-static void s2io_set_multicast(struct net_device *dev);
+static void s2io_set_multicast(struct net_device *dev, bool may_sleep);
 static int rx_osm_handler(struct ring_info *ring_data, struct RxD_t * rxdp);
 static void s2io_link(struct s2io_nic * sp, int link);
 static void s2io_reset(struct s2io_nic * sp);
@@ -1087,7 +1087,7 @@ static int s2io_set_swapper(struct s2io_nic * sp);
 static void s2io_card_down(struct s2io_nic *nic);
 static int s2io_card_up(struct s2io_nic *nic);
 static int wait_for_cmd_complete(void __iomem *addr, u64 busy_bit,
-					int bit_state);
+				 int bit_state, bool may_sleep);
 static int s2io_add_isr(struct s2io_nic * sp);
 static void s2io_rem_isr(struct s2io_nic * sp);
 
diff --git a/drivers/net/ethernet/nvidia/forcedeth.c b/drivers/net/ethernet/nvidia/forcedeth.c
index 2fc10a36afa4..7e85cf943be1 100644
--- a/drivers/net/ethernet/nvidia/forcedeth.c
+++ b/drivers/net/ethernet/nvidia/forcedeth.c
@@ -1666,11 +1666,7 @@ static void nv_update_stats(struct net_device *dev)
 	struct fe_priv *np = netdev_priv(dev);
 	u8 __iomem *base = get_hwbase(dev);
 
-	/* If it happens that this is run in top-half context, then
-	 * replace the spin_lock of hwstats_lock with
-	 * spin_lock_irqsave() in calling functions. */
-	WARN_ONCE(in_irq(), "forcedeth: estats spin_lock(_bh) from top-half");
-	assert_spin_locked(&np->hwstats_lock);
+	lockdep_assert_held(&np->hwstats_lock);
 
 	/* query hardware */
 	np->estats.tx_bytes += readl(base + NvRegTxCnt);
diff --git a/drivers/net/ethernet/ti/tlan.c b/drivers/net/ethernet/ti/tlan.c
index 267c080ee084..0b2ce4bdc2c3 100644
--- a/drivers/net/ethernet/ti/tlan.c
+++ b/drivers/net/ethernet/ti/tlan.c
@@ -186,6 +186,7 @@ static void	tlan_reset_adapter(struct net_device *);
 static void	tlan_finish_reset(struct net_device *);
 static void	tlan_set_mac(struct net_device *, int areg, char *mac);
 
+static void	__tlan_phy_print(struct net_device *);
 static void	tlan_phy_print(struct net_device *);
 static void	tlan_phy_detect(struct net_device *);
 static void	tlan_phy_power_down(struct net_device *);
@@ -201,9 +202,11 @@ static void	tlan_phy_finish_auto_neg(struct net_device *);
   static int	tlan_phy_dp83840a_check(struct net_device *);
 */
 
-static bool	tlan_mii_read_reg(struct net_device *, u16, u16, u16 *);
+static bool	__tlan_mii_read_reg(struct net_device *, u16, u16, u16 *);
+static void	tlan_mii_read_reg(struct net_device *, u16, u16, u16 *);
 static void	tlan_mii_send_data(u16, u32, unsigned);
 static void	tlan_mii_sync(u16);
+static void	__tlan_mii_write_reg(struct net_device *, u16, u16, u16);
 static void	tlan_mii_write_reg(struct net_device *, u16, u16, u16);
 
 static void	tlan_ee_send_start(u16);
@@ -242,23 +245,20 @@ static u32
 	tlan_handle_rx_eoc
 };
 
-static inline void
+static void
 tlan_set_timer(struct net_device *dev, u32 ticks, u32 type)
 {
 	struct tlan_priv *priv = netdev_priv(dev);
 	unsigned long flags = 0;
 
-	if (!in_irq())
-		spin_lock_irqsave(&priv->lock, flags);
+	spin_lock_irqsave(&priv->lock, flags);
 	if (priv->timer.function != NULL &&
 	    priv->timer_type != TLAN_TIMER_ACTIVITY) {
-		if (!in_irq())
-			spin_unlock_irqrestore(&priv->lock, flags);
+		spin_unlock_irqrestore(&priv->lock, flags);
 		return;
 	}
 	priv->timer.function = tlan_timer;
-	if (!in_irq())
-		spin_unlock_irqrestore(&priv->lock, flags);
+	spin_unlock_irqrestore(&priv->lock, flags);
 
 	priv->timer_set_at = jiffies;
 	priv->timer_type = type;
@@ -1703,22 +1703,22 @@ static u32 tlan_handle_status_check(struct net_device *dev, u16 host_int)
 				 dev->name, (unsigned) net_sts);
 		}
 		if ((net_sts & TLAN_NET_STS_MIRQ) &&  (priv->phy_num == 0)) {
-			tlan_mii_read_reg(dev, phy, TLAN_TLPHY_STS, &tlphy_sts);
-			tlan_mii_read_reg(dev, phy, TLAN_TLPHY_CTL, &tlphy_ctl);
+			__tlan_mii_read_reg(dev, phy, TLAN_TLPHY_STS, &tlphy_sts);
+			__tlan_mii_read_reg(dev, phy, TLAN_TLPHY_CTL, &tlphy_ctl);
 			if (!(tlphy_sts & TLAN_TS_POLOK) &&
 			    !(tlphy_ctl & TLAN_TC_SWAPOL)) {
 				tlphy_ctl |= TLAN_TC_SWAPOL;
-				tlan_mii_write_reg(dev, phy, TLAN_TLPHY_CTL,
-						   tlphy_ctl);
+				__tlan_mii_write_reg(dev, phy, TLAN_TLPHY_CTL,
+						     tlphy_ctl);
 			} else if ((tlphy_sts & TLAN_TS_POLOK) &&
 				   (tlphy_ctl & TLAN_TC_SWAPOL)) {
 				tlphy_ctl &= ~TLAN_TC_SWAPOL;
-				tlan_mii_write_reg(dev, phy, TLAN_TLPHY_CTL,
-						   tlphy_ctl);
+				__tlan_mii_write_reg(dev, phy, TLAN_TLPHY_CTL,
+						     tlphy_ctl);
 			}
 
 			if (debug)
-				tlan_phy_print(dev);
+				__tlan_phy_print(dev);
 		}
 	}
 
@@ -2379,7 +2379,7 @@ ThunderLAN driver PHY layer routines
 
 
 /*********************************************************************
- *	tlan_phy_print
+ *	__tlan_phy_print
  *
  *	Returns:
  *		Nothing
@@ -2391,11 +2391,13 @@ ThunderLAN driver PHY layer routines
  *
  ********************************************************************/
 
-static void tlan_phy_print(struct net_device *dev)
+static void __tlan_phy_print(struct net_device *dev)
 {
 	struct tlan_priv *priv = netdev_priv(dev);
 	u16 i, data0, data1, data2, data3, phy;
 
+	lockdep_assert_held(&priv->lock);
+
 	phy = priv->phy[priv->phy_num];
 
 	if (priv->adapter->flags & TLAN_ADAPTER_UNMANAGED_PHY) {
@@ -2404,10 +2406,10 @@ static void tlan_phy_print(struct net_device *dev)
 		netdev_info(dev, "PHY 0x%02x\n", phy);
 		pr_info("   Off.  +0     +1     +2     +3\n");
 		for (i = 0; i < 0x20; i += 4) {
-			tlan_mii_read_reg(dev, phy, i, &data0);
-			tlan_mii_read_reg(dev, phy, i + 1, &data1);
-			tlan_mii_read_reg(dev, phy, i + 2, &data2);
-			tlan_mii_read_reg(dev, phy, i + 3, &data3);
+			__tlan_mii_read_reg(dev, phy, i, &data0);
+			__tlan_mii_read_reg(dev, phy, i + 1, &data1);
+			__tlan_mii_read_reg(dev, phy, i + 2, &data2);
+			__tlan_mii_read_reg(dev, phy, i + 3, &data3);
 			pr_info("   0x%02x 0x%04hx 0x%04hx 0x%04hx 0x%04hx\n",
 				i, data0, data1, data2, data3);
 		}
@@ -2417,7 +2419,15 @@ static void tlan_phy_print(struct net_device *dev)
 
 }
 
+static void tlan_phy_print(struct net_device *dev)
+{
+	struct tlan_priv *priv = netdev_priv(dev);
+	unsigned long flags;
 
+	spin_lock_irqsave(&priv->lock, flags);
+	__tlan_phy_print(dev);
+	spin_unlock_irqrestore(&priv->lock, flags);
+}
 
 
 /*********************************************************************
@@ -2795,7 +2805,7 @@ these routines are based on the information in chap. 2 of the
 
 
 /***************************************************************
- *	tlan_mii_read_reg
+ *	__tlan_mii_read_reg
  *
  *	Returns:
  *		false	if ack received ok
@@ -2819,7 +2829,7 @@ these routines are based on the information in chap. 2 of the
  **************************************************************/
 
 static bool
-tlan_mii_read_reg(struct net_device *dev, u16 phy, u16 reg, u16 *val)
+__tlan_mii_read_reg(struct net_device *dev, u16 phy, u16 reg, u16 *val)
 {
 	u8	nack;
 	u16	sio, tmp;
@@ -2827,15 +2837,13 @@ tlan_mii_read_reg(struct net_device *dev, u16 phy, u16 reg, u16 *val)
 	bool	err;
 	int	minten;
 	struct tlan_priv *priv = netdev_priv(dev);
-	unsigned long flags = 0;
+
+	lockdep_assert_held(&priv->lock);
 
 	err = false;
 	outw(TLAN_NET_SIO, dev->base_addr + TLAN_DIO_ADR);
 	sio = dev->base_addr + TLAN_DIO_DATA + TLAN_NET_SIO;
 
-	if (!in_irq())
-		spin_lock_irqsave(&priv->lock, flags);
-
 	tlan_mii_sync(dev->base_addr);
 
 	minten = tlan_get_bit(TLAN_NET_SIO_MINTEN, sio);
@@ -2881,15 +2889,19 @@ tlan_mii_read_reg(struct net_device *dev, u16 phy, u16 reg, u16 *val)
 
 	*val = tmp;
 
-	if (!in_irq())
-		spin_unlock_irqrestore(&priv->lock, flags);
-
 	return err;
-
 }
 
+static void tlan_mii_read_reg(struct net_device *dev, u16 phy, u16 reg,
+			      u16 *val)
+{
+	struct tlan_priv *priv = netdev_priv(dev);
+	unsigned long flags;
 
-
+	spin_lock_irqsave(&priv->lock, flags);
+	__tlan_mii_read_reg(dev, phy, reg, val);
+	spin_unlock_irqrestore(&priv->lock, flags);
+}
 
 /***************************************************************
  *	tlan_mii_send_data
@@ -2971,7 +2983,7 @@ static void tlan_mii_sync(u16 base_port)
 
 
 /***************************************************************
- *	tlan_mii_write_reg
+ *	__tlan_mii_write_reg
  *
  *	Returns:
  *		Nothing
@@ -2991,19 +3003,17 @@ static void tlan_mii_sync(u16 base_port)
  **************************************************************/
 
 static void
-tlan_mii_write_reg(struct net_device *dev, u16 phy, u16 reg, u16 val)
+__tlan_mii_write_reg(struct net_device *dev, u16 phy, u16 reg, u16 val)
 {
 	u16	sio;
 	int	minten;
-	unsigned long flags = 0;
 	struct tlan_priv *priv = netdev_priv(dev);
 
+	lockdep_assert_held(&priv->lock);
+
 	outw(TLAN_NET_SIO, dev->base_addr + TLAN_DIO_ADR);
 	sio = dev->base_addr + TLAN_DIO_DATA + TLAN_NET_SIO;
 
-	if (!in_irq())
-		spin_lock_irqsave(&priv->lock, flags);
-
 	tlan_mii_sync(dev->base_addr);
 
 	minten = tlan_get_bit(TLAN_NET_SIO_MINTEN, sio);
@@ -3024,12 +3034,18 @@ tlan_mii_write_reg(struct net_device *dev, u16 phy, u16 reg, u16 val)
 	if (minten)
 		tlan_set_bit(TLAN_NET_SIO_MINTEN, sio);
 
-	if (!in_irq())
-		spin_unlock_irqrestore(&priv->lock, flags);
-
 }
 
+static void
+tlan_mii_write_reg(struct net_device *dev, u16 phy, u16 reg, u16 val)
+{
+	struct tlan_priv *priv = netdev_priv(dev);
+	unsigned long flags;
 
+	spin_lock_irqsave(&priv->lock, flags);
+	__tlan_mii_write_reg(dev, phy, reg, val);
+	spin_unlock_irqrestore(&priv->lock, flags);
+}
 
 
 /*****************************************************************************