ARM/PCI: Replace panic with WARN messages on failures

In the ARM PCI bios32 layer, failures to dynamically allocate pci_sys_data
for a PCI bus, or a PCI bus scan failure have to be considered serious
warnings but they should not trigger a system panic so that at least the
system is given a chance to be debugged.

This patch replaces the panic statements with WARN() messages to improve
error reporting in the ARM PCI bios32 layer.

Signed-off-by: Lorenzo Pieralisi <lorenzo.pieralisi@arm.com>
Signed-off-by: Bjorn Helgaas <bhelgaas@google.com>
Reviewed-by: Jingoo Han <jingoohan1@gmail.com>
Acked-by: Marc Zyngier <marc.zyngier@arm.com>
CC: Russell King <linux@arm.linux.org.uk>
CC: Marc Zyngier <marc.zyngier@arm.com>

arch/arm/kernel/bios32.c

@@ -459,8 +459,8 @@ static void pcibios_init_hw(struct device *parent, struct hw_pci *hw,
 
 	for (nr = busnr = 0; nr < hw->nr_controllers; nr++) {
 		sys = kzalloc(sizeof(struct pci_sys_data), GFP_KERNEL);
-		if (!sys)
-			panic("PCI: unable to allocate sys data!");
+		if (WARN(!sys, "PCI: unable to allocate sys data!"))
+			break;
 
 #ifdef CONFIG_PCI_MSI
 		sys->msi_ctrl = hw->msi_ctrl;
@@ -489,8 +489,10 @@ static void pcibios_init_hw(struct device *parent, struct hw_pci *hw,
 				sys->bus = pci_scan_root_bus(parent, sys->busnr,
 						hw->ops, sys, &sys->resources);
 
-			if (!sys->bus)
-				panic("PCI: unable to scan bus!");
+			if (WARN(!sys->bus, "PCI: unable to scan bus!")) {
+				kfree(sys);
+				break;
+			}
 
 			busnr = sys->bus->busn_res.end + 1;