diff options
| author | Arthur Heymans <arthur@aheymans.xyz> | 2022-12-08 14:25:11 +0100 |
|---|---|---|
| committer | Lean Sheng Tan <sheng.tan@9elements.com> | 2023-05-14 13:00:25 +0000 |
| commit | d1c61a8e70422d746c3096821bb479b2014248f0 (patch) | |
| tree | 1e719c6adf7172bdf607aa35cdd35701e7703c15 /src | |
| parent | 0e1f08d1fbb09eb0a14b23f231f1a62697af9ccd (diff) | |
arch/x86/ioapic.c: Increase the number of bits for ioapic ID
In practice hardware can use larger numbers.
Change-Id: I6e9ddd1ebd396c37e25eb3019f981d45d9c5e062
Signed-off-by: Arthur Heymans <arthur@aheymans.xyz>
Reviewed-on: https://review.coreboot.org/c/coreboot/+/70499
Tested-by: build bot (Jenkins) <no-reply@coreboot.org>
Reviewed-by: Naresh Solanki <naresh.solanki.2011@gmail.com>
Reviewed-by: Kyösti Mälkki <kyosti.malkki@gmail.com>
Diffstat (limited to 'src')
| -rw-r--r-- | src/arch/x86/ioapic.c | 7 |
1 files changed, 6 insertions, 1 deletions
diff --git a/src/arch/x86/ioapic.c b/src/arch/x86/ioapic.c index 84a4c7f7bc..04c852b4c2 100644 --- a/src/arch/x86/ioapic.c +++ b/src/arch/x86/ioapic.c @@ -147,7 +147,12 @@ static void set_ioapic_id(void *ioapic_base, u8 ioapic_id) u8 get_ioapic_id(void *ioapic_base) { - return (io_apic_read(ioapic_base, 0x00) >> 24) & 0x0f; + /* + * According to 82093AA I/O ADVANCED PROGRAMMABLE INTERRUPT CONTROLLER (IOAPIC) + * only 4 bits (24:27) are used for the ID. In practice the upper bits are either + * always 0 or used for larger IDs. + */ + return (io_apic_read(ioapic_base, 0x00) >> 24) & 0xff; } u8 get_ioapic_version(void *ioapic_base) |