bcma: make bcma_core_pci_{up,down}() callable from atomic context

This patch removes the bcma_core_pci_power_save() call from
the bcma_core_pci_{up,down}() functions as it tries to schedule
thus requiring to call them from non-atomic context. The function
bcma_core_pci_power_save() is now exported so the calling module
can explicitly use it in non-atomic context. This fixes the
'scheduling while atomic' issue reported by Tod Jackson and
Joe Perches.

[ 13.210710] BUG: scheduling while atomic: dhcpcd/1800/0x00000202
[ 13.210718] Modules linked in: brcmsmac nouveau coretemp kvm_intel kvm cordic brcmutil bcma dell_wmi atl1c ttm mxm_wmi wmi
[ 13.210756] CPU: 2 PID: 1800 Comm: dhcpcd Not tainted 3.11.0-wl #1
[ 13.210762] Hardware name: Alienware M11x R2/M11x R2, BIOS A04 11/23/2010
[ 13.210767] ffff880177c92c40 ffff880170fd1948 ffffffff8169af5b 0000000000000007
[ 13.210777] ffff880170fd1ab0 ffff880170fd1958 ffffffff81697ee2 ffff880170fd19d8
[ 13.210785] ffffffff816a19f5 00000000000f4240 000000000000d080 ffff880170fd1fd8
[ 13.210794] Call Trace:
[ 13.210813] [<ffffffff8169af5b>] dump_stack+0x4f/0x84
[ 13.210826] [<ffffffff81697ee2>] __schedule_bug+0x43/0x51
[ 13.210837] [<ffffffff816a19f5>] __schedule+0x6e5/0x810
[ 13.210845] [<ffffffff816a1c34>] schedule+0x24/0x70
[ 13.210855] [<ffffffff816a04fc>] schedule_hrtimeout_range_clock+0x10c/0x150
[ 13.210867] [<ffffffff810684e0>] ? update_rmtp+0x60/0x60
[ 13.210877] [<ffffffff8106915f>] ? hrtimer_start_range_ns+0xf/0x20
[ 13.210887] [<ffffffff816a054e>] schedule_hrtimeout_range+0xe/0x10
[ 13.210897] [<ffffffff8104f6fb>] usleep_range+0x3b/0x40
[ 13.210910] [<ffffffffa00371af>] bcma_pcie_mdio_set_phy.isra.3+0x4f/0x80 [bcma]
[ 13.210921] [<ffffffffa003729f>] bcma_pcie_mdio_write.isra.4+0xbf/0xd0 [bcma]
[ 13.210932] [<ffffffffa0037498>] bcma_pcie_mdio_writeread.isra.6.constprop.13+0x18/0x30 [bcma]
[ 13.210942] [<ffffffffa00374ee>] bcma_core_pci_power_save+0x3e/0x80 [bcma]
[ 13.210953] [<ffffffffa003765d>] bcma_core_pci_up+0x2d/0x60 [bcma]
[ 13.210975] [<ffffffffa03dc17c>] brcms_c_up+0xfc/0x430 [brcmsmac]
[ 13.210989] [<ffffffffa03d1a7d>] brcms_up+0x1d/0x20 [brcmsmac]
[ 13.211003] [<ffffffffa03d2498>] brcms_ops_start+0x298/0x340 [brcmsmac]
[ 13.211020] [<ffffffff81600a12>] ? cfg80211_netdev_notifier_call+0xd2/0x5f0
[ 13.211030] [<ffffffff815fa53d>] ? packet_notifier+0xad/0x1d0
[ 13.211064] [<ffffffff81656e75>] ieee80211_do_open+0x325/0xf80
[ 13.211076] [<ffffffff8106ac09>] ? __raw_notifier_call_chain+0x9/0x10
[ 13.211086] [<ffffffff81657b41>] ieee80211_open+0x71/0x80
[ 13.211101] [<ffffffff81526267>] __dev_open+0x87/0xe0
[ 13.211109] [<ffffffff8152650c>] __dev_change_flags+0x9c/0x180
[ 13.211117] [<ffffffff815266a3>] dev_change_flags+0x23/0x70
[ 13.211127] [<ffffffff8158cd68>] devinet_ioctl+0x5b8/0x6a0
[ 13.211136] [<ffffffff8158d5c5>] inet_ioctl+0x75/0x90
[ 13.211147] [<ffffffff8150b38b>] sock_do_ioctl+0x2b/0x70
[ 13.211155] [<ffffffff8150b681>] sock_ioctl+0x71/0x2a0
[ 13.211169] [<ffffffff8114ed47>] do_vfs_ioctl+0x87/0x520
[ 13.211180] [<ffffffff8113f159>] ? ____fput+0x9/0x10
[ 13.211198] [<ffffffff8106228c>] ? task_work_run+0x9c/0xd0
[ 13.211202] [<ffffffff8114f271>] SyS_ioctl+0x91/0xb0
[ 13.211208] [<ffffffff816aa252>] system_call_fastpath+0x16/0x1b
[ 13.211217] NOHZ: local_softirq_pending 202

The issue was introduced in v3.11 kernel by following commit:

commit aa51e598d04c6acf5477934cd6383f5a17ce9029
Author: Hauke Mehrtens <[e-mail]>
Date: Sat Aug 24 00:32:31 2013 +0200

brcmsmac: use bcma PCIe up and down functions

replace the calls to bcma_core_pci_extend_L1timer() by calls to the
newly introduced bcma_core_pci_ip() and bcma_core_pci_down()

Signed-off-by: Hauke Mehrtens <[e-mail]>
Cc: Arend van Spriel <[e-mail]>
Signed-off-by: John W. Linville <[e-mail]>

This fix has been discussed with Hauke Mehrtens [1] selection
option 3) and is intended for v3.12.

Ref:
[1] http://mid.gmane.org/[e-mail]

Cc: <[e-mail]> # 3.11.x
Cc: Tod Jackson <[e-mail]>
Cc: Joe Perches <[e-mail]>
Cc: Rafal Milecki <[e-mail]>
Cc: Hauke Mehrtens <[e-mail]>
Reviewed-by: Hante Meuleman <[e-mail]>
Signed-off-by: Arend van Spriel <[e-mail]>
Signed-off-by: John W. Linville <[e-mail]>

drivers/bcma/driver_pci.c

···
 	}
 }
 
-static void bcma_core_pci_power_save(struct bcma_drv_pci *pc, bool up)
-{
-	u16 data;
-
-	if (pc->core->id.rev >= 15 && pc->core->id.rev <= 20) {
-		data = up ? 0x74 : 0x7C;
-		bcma_pcie_mdio_writeread(pc, BCMA_CORE_PCI_MDIO_BLK1,
-					 BCMA_CORE_PCI_MDIO_BLK1_MGMT1, 0x7F64);
-		bcma_pcie_mdio_writeread(pc, BCMA_CORE_PCI_MDIO_BLK1,
-					 BCMA_CORE_PCI_MDIO_BLK1_MGMT3, data);
-	} else if (pc->core->id.rev >= 21 && pc->core->id.rev <= 22) {
-		data = up ? 0x75 : 0x7D;
-		bcma_pcie_mdio_writeread(pc, BCMA_CORE_PCI_MDIO_BLK1,
-					 BCMA_CORE_PCI_MDIO_BLK1_MGMT1, 0x7E65);
-		bcma_pcie_mdio_writeread(pc, BCMA_CORE_PCI_MDIO_BLK1,
-					 BCMA_CORE_PCI_MDIO_BLK1_MGMT3, data);
-	}
-}
-
 /**************************************************
  * Init.
  **************************************************/
···
 	if (!pc->hostmode)
 		bcma_core_pci_clientmode_init(pc);
 }
+
+void bcma_core_pci_power_save(struct bcma_bus *bus, bool up)
+{
+	struct bcma_drv_pci *pc;
+	u16 data;
+
+	if (bus->hosttype != BCMA_HOSTTYPE_PCI)
+		return;
+
+	pc = &bus->drv_pci[0];
+
+	if (pc->core->id.rev >= 15 && pc->core->id.rev <= 20) {
+		data = up ? 0x74 : 0x7C;
+		bcma_pcie_mdio_writeread(pc, BCMA_CORE_PCI_MDIO_BLK1,
+					 BCMA_CORE_PCI_MDIO_BLK1_MGMT1, 0x7F64);
+		bcma_pcie_mdio_writeread(pc, BCMA_CORE_PCI_MDIO_BLK1,
+					 BCMA_CORE_PCI_MDIO_BLK1_MGMT3, data);
+	} else if (pc->core->id.rev >= 21 && pc->core->id.rev <= 22) {
+		data = up ? 0x75 : 0x7D;
+		bcma_pcie_mdio_writeread(pc, BCMA_CORE_PCI_MDIO_BLK1,
+					 BCMA_CORE_PCI_MDIO_BLK1_MGMT1, 0x7E65);
+		bcma_pcie_mdio_writeread(pc, BCMA_CORE_PCI_MDIO_BLK1,
+					 BCMA_CORE_PCI_MDIO_BLK1_MGMT3, data);
+	}
+}
+EXPORT_SYMBOL_GPL(bcma_core_pci_power_save);
 
 int bcma_core_pci_irq_ctl(struct bcma_drv_pci *pc, struct bcma_device *core,
 			  bool enable)
···
 
 	pc = &bus->drv_pci[0];
 
-	bcma_core_pci_power_save(pc, true);
-
 	bcma_core_pci_extend_L1timer(pc, true);
 }
 EXPORT_SYMBOL_GPL(bcma_core_pci_up);
···
 	pc = &bus->drv_pci[0];
 
 	bcma_core_pci_extend_L1timer(pc, false);
-
-	bcma_core_pci_power_save(pc, false);
 }
 EXPORT_SYMBOL_GPL(bcma_core_pci_down);

include/linux/bcma/bcma_driver_pci.h

···
 				 struct bcma_device *core, bool enable);
 extern void bcma_core_pci_up(struct bcma_bus *bus);
 extern void bcma_core_pci_down(struct bcma_bus *bus);
+extern void bcma_core_pci_power_save(struct bcma_bus *bus, bool up);
 
 extern int bcma_core_pci_pcibios_map_irq(const struct pci_dev *dev);
 extern int bcma_core_pci_plat_dev_init(struct pci_dev *dev);