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 <[email protected]>
Signed-off-by: Ilya Lipnitskiy <[email protected]>
---
arch/mips/pci/pci-rt2880.c | 13 -------------
1 file changed, 13 deletions(-)
diff --git a/arch/mips/pci/pci-rt2880.c b/arch/mips/pci/pci-rt2880.c
index f1538d2be89e..e9dd01431f21 100644
--- a/arch/mips/pci/pci-rt2880.c
+++ b/arch/mips/pci/pci-rt2880.c
@@ -41,7 +41,6 @@
#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)
{
@@ -63,17 +62,14 @@ static inline u32 rt2880_pci_get_cfgaddr(unsigned int bus, unsigned int slot,
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:
@@ -93,14 +89,12 @@ static int rt2880_pci_config_read(struct pci_bus *bus, unsigned int devfn,
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);
@@ -119,7 +113,6 @@ static int rt2880_pci_config_write(struct pci_bus *bus, unsigned int devfn,
}
rt2880_pci_reg_write(data, RT2880_PCI_REG_CONFIG_DATA);
- spin_unlock_irqrestore(&rt2880_pci_lock, flags);
return PCIBIOS_SUCCESSFUL;
}
@@ -151,31 +144,25 @@ static struct pci_controller rt2880_pci_controller = {
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)
--
2.31.1
On Wed, Apr 14, 2021 at 6:12 AM Ilya Lipnitskiy
<[email protected]> wrote:
> 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 <[email protected]>
> Signed-off-by: Ilya Lipnitskiy <[email protected]>
Reviewed-by: Sergey Ryazanov <[email protected]>
--
Sergey