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| author | Wu Zhangjin <wuzhangjin@gmail.com> | 2010-03-10 21:52:07 +0800 |
|---|---|---|
| committer | Wu Zhangjin <wuzhangjin@gmail.com> | 2010-03-11 19:54:28 +0800 |
| commit | a6310a884cd9bb469c6267554c3913ad8300b55c (patch) | |
| tree | ec6fe9919fccc4e24a08cf625e3b5a75d6c43928 | |
| parent | 6329865ed6774b1d1cb3ab585bce263b2babfcd4 (diff) | |
| download | lwn-a6310a884cd9bb469c6267554c3913ad8300b55c.tar.gz lwn-a6310a884cd9bb469c6267554c3913ad8300b55c.zip | |
Loongson: make _rdmsr, _wrmsr be atomic
The _rdmsr, _wrdmsr operation must be atomic to ensure accessing the
right msr address we want.
Signed-off-by: Wu Zhangjin <wuzhangjin@gmail.com>
| -rw-r--r-- | arch/mips/pci/ops-loongson2.c | 11 |
1 files changed, 11 insertions, 0 deletions
diff --git a/arch/mips/pci/ops-loongson2.c b/arch/mips/pci/ops-loongson2.c index aa5d3da27212..98aa2f31d822 100644 --- a/arch/mips/pci/ops-loongson2.c +++ b/arch/mips/pci/ops-loongson2.c @@ -182,15 +182,22 @@ struct pci_ops loongson_pci_ops = { }; #ifdef CONFIG_CS5536 + +DEFINE_RAW_SPINLOCK(msr_lock); + void _rdmsr(u32 msr, u32 *hi, u32 *lo) { struct pci_bus bus = { .number = PCI_BUS_CS5536 }; u32 devfn = PCI_DEVFN(PCI_IDSEL_CS5536, 0); + unsigned long flags; + + raw_spin_lock_irqsave(&msr_lock, flags); loongson_pcibios_write(&bus, devfn, PCI_MSR_ADDR, 4, msr); loongson_pcibios_read(&bus, devfn, PCI_MSR_DATA_LO, 4, lo); loongson_pcibios_read(&bus, devfn, PCI_MSR_DATA_HI, 4, hi); + raw_spin_unlock_irqrestore(&msr_lock, flags); } EXPORT_SYMBOL(_rdmsr); @@ -200,9 +207,13 @@ void _wrmsr(u32 msr, u32 hi, u32 lo) .number = PCI_BUS_CS5536 }; u32 devfn = PCI_DEVFN(PCI_IDSEL_CS5536, 0); + unsigned long flags; + + raw_spin_lock_irqsave(&msr_lock, flags); loongson_pcibios_write(&bus, devfn, PCI_MSR_ADDR, 4, msr); loongson_pcibios_write(&bus, devfn, PCI_MSR_DATA_LO, 4, lo); loongson_pcibios_write(&bus, devfn, PCI_MSR_DATA_HI, 4, hi); + raw_spin_unlock_irqrestore(&msr_lock, flags); } EXPORT_SYMBOL(_wrmsr); #endif |