diff options
Diffstat (limited to 'payloads/libpayload/arch/x86/apic.c')
| -rw-r--r-- | payloads/libpayload/arch/x86/apic.c | 23 |
1 files changed, 21 insertions, 2 deletions
diff --git a/payloads/libpayload/arch/x86/apic.c b/payloads/libpayload/arch/x86/apic.c index 048cc66fb8..3b294cbb94 100644 --- a/payloads/libpayload/arch/x86/apic.c +++ b/payloads/libpayload/arch/x86/apic.c @@ -58,6 +58,8 @@ #define APIC_TIMER_INIT_COUNT 0x380 #define APIC_TIMER_CUR_COUNT 0x390 #define APIC_TIMER_DIV_CFG 0x3E0 +#define APIC_ISR_0 0x100 +#define APIC_ISR_OFFSET 0x010 #define APIC_LVT_SIZE 0x010 @@ -141,11 +143,28 @@ static void timer_interrupt_handler(u8 vector) timer_waiting = 0; } -void apic_eoi(void) +void apic_eoi(uint8_t vector) { die_if(!apic_bar, "APIC is not initialized"); - apic_write32(APIC_EOI, 0); + /* + * Local and I/O APICs support 240 vectors (in the range of 16 to 255) + * as valid interrupts. + */ + if (vector <= 15) + return; + + /* Each bank handles 32 vectors */ + uint8_t bank = vector / 32; + + uint32_t offset = APIC_ISR_0 + bank * APIC_ISR_OFFSET; + + uint32_t mask = apic_read32(offset); + + uint8_t shift = vector % 32; + + if (mask & (1 << shift)) + apic_write32(APIC_EOI, 0); } static enum APIC_CAPABILITY apic_capabilities(void) |