diff options
| -rw-r--r-- | arch/x86_64/kernel/io_apic.c | 26 |
1 files changed, 23 insertions, 3 deletions
diff --git a/arch/x86_64/kernel/io_apic.c b/arch/x86_64/kernel/io_apic.c index 96e02d84571..3b8f9c68ad3 100644 --- a/arch/x86_64/kernel/io_apic.c +++ b/arch/x86_64/kernel/io_apic.c @@ -172,12 +172,34 @@ static struct IO_APIC_route_entry ioapic_read_entry(int apic, int pin) return eu.entry; } +/* + * When we write a new IO APIC routing entry, we need to write the high + * word first! If the mask bit in the low word is clear, we will enable + * the interrupt, and we need to make sure the entry is fully populated + * before that happens. + */ static void ioapic_write_entry(int apic, int pin, struct IO_APIC_route_entry e) { unsigned long flags; union entry_union eu; eu.entry = e; spin_lock_irqsave(&ioapic_lock, flags); + io_apic_write(apic, 0x11 + 2*pin, eu.w2); + io_apic_write(apic, 0x10 + 2*pin, eu.w1); + spin_unlock_irqrestore(&ioapic_lock, flags); +} + +/* + * When we mask an IO APIC routing entry, we need to write the low + * word first, in order to set the mask bit before we change the + * high bits! + */ +static void ioapic_mask_entry(int apic, int pin) +{ + unsigned long flags; + union entry_union eu = { .entry.mask = 1 }; + + spin_lock_irqsave(&ioapic_lock, flags); io_apic_write(apic, 0x10 + 2*pin, eu.w1); io_apic_write(apic, 0x11 + 2*pin, eu.w2); spin_unlock_irqrestore(&ioapic_lock, flags); @@ -302,9 +324,7 @@ static void clear_IO_APIC_pin(unsigned int apic, unsigned int pin) /* * Disable it in the IO-APIC irq-routing table: */ - memset(&entry, 0, sizeof(entry)); - entry.mask = 1; - ioapic_write_entry(apic, pin, entry); + ioapic_mask_entry(apic, pin); } static void clear_IO_APIC (void) |