MIPS: pci-rt2880: remove unneeded locks

Mirror pci-rt3883 fix from commit e5067c718b3a ("MIPS: pci-rt3883:
Remove odd locking in PCI config space access code"). pci-rt2880 shares
the driver layout with pci-rt3883 and the same reasons apply.

Caller (generic PCI code) already does proper locking, so no need to add
another one here. Local PCI read/write functions are never called
simultaneously, also they do not require synchronization with the PCI
controller ops, since they are used before the controller registration.

Suggested-by: Sergey Ryazanov <[e-mail]>
Signed-off-by: Ilya Lipnitskiy <[e-mail]>
Reviewed-by: Sergey Ryazanov <[e-mail]>
Signed-off-by: Thomas Bogendoerfer <[e-mail]>

arch/mips/pci/pci-rt2880.c

···
 #define RT2880_PCI_REG_ARBCTL		0x80
 
 static void __iomem *rt2880_pci_base;
-static DEFINE_SPINLOCK(rt2880_pci_lock);
 
 static u32 rt2880_pci_reg_read(u32 reg)
 {
···
 static int rt2880_pci_config_read(struct pci_bus *bus, unsigned int devfn,
 				  int where, int size, u32 *val)
 {
-	unsigned long flags;
 	u32 address;
 	u32 data;
 
 	address = rt2880_pci_get_cfgaddr(bus->number, PCI_SLOT(devfn),
 					 PCI_FUNC(devfn), where);
 
-	spin_lock_irqsave(&rt2880_pci_lock, flags);
 	rt2880_pci_reg_write(address, RT2880_PCI_REG_CONFIG_ADDR);
 	data = rt2880_pci_reg_read(RT2880_PCI_REG_CONFIG_DATA);
-	spin_unlock_irqrestore(&rt2880_pci_lock, flags);
 
 	switch (size) {
 	case 1:
···
 static int rt2880_pci_config_write(struct pci_bus *bus, unsigned int devfn,
 				   int where, int size, u32 val)
 {
-	unsigned long flags;
 	u32 address;
 	u32 data;
 
 	address = rt2880_pci_get_cfgaddr(bus->number, PCI_SLOT(devfn),
 					 PCI_FUNC(devfn), where);
 
-	spin_lock_irqsave(&rt2880_pci_lock, flags);
 	rt2880_pci_reg_write(address, RT2880_PCI_REG_CONFIG_ADDR);
 	data = rt2880_pci_reg_read(RT2880_PCI_REG_CONFIG_DATA);
 
···
 	}
 
 	rt2880_pci_reg_write(data, RT2880_PCI_REG_CONFIG_DATA);
-	spin_unlock_irqrestore(&rt2880_pci_lock, flags);
 
 	return PCIBIOS_SUCCESSFUL;
 }
···
 
 static inline u32 rt2880_pci_read_u32(unsigned long reg)
 {
-	unsigned long flags;
 	u32 address;
 	u32 ret;
 
 	address = rt2880_pci_get_cfgaddr(0, 0, 0, reg);
 
-	spin_lock_irqsave(&rt2880_pci_lock, flags);
 	rt2880_pci_reg_write(address, RT2880_PCI_REG_CONFIG_ADDR);
 	ret = rt2880_pci_reg_read(RT2880_PCI_REG_CONFIG_DATA);
-	spin_unlock_irqrestore(&rt2880_pci_lock, flags);
 
 	return ret;
 }
 
 static inline void rt2880_pci_write_u32(unsigned long reg, u32 val)
 {
-	unsigned long flags;
 	u32 address;
 
 	address = rt2880_pci_get_cfgaddr(0, 0, 0, reg);
 
-	spin_lock_irqsave(&rt2880_pci_lock, flags);
 	rt2880_pci_reg_write(address, RT2880_PCI_REG_CONFIG_ADDR);
 	rt2880_pci_reg_write(val, RT2880_PCI_REG_CONFIG_DATA);
-	spin_unlock_irqrestore(&rt2880_pci_lock, flags);
 }
 
 int pcibios_map_irq(const struct pci_dev *dev, u8 slot, u8 pin)