diff options
| author | Suresh Siddha <suresh.b.siddha@intel.com> | 2010-01-13 16:19:11 -0800 |
|---|---|---|
| committer | H. Peter Anvin <hpa@zytor.com> | 2010-01-18 10:59:59 -0800 |
| commit | 6579b474572fd54c583ac074e8e7aaae926c62ef (patch) | |
| tree | d84740df8c254be8d8875c8caaedf2da3124076a /arch/x86/kernel | |
| parent | 722b3654852e48b93367a63f8ada9ee1cd43f2d3 (diff) | |
| download | blackbird-op-linux-6579b474572fd54c583ac074e8e7aaae926c62ef.tar.gz blackbird-op-linux-6579b474572fd54c583ac074e8e7aaae926c62ef.zip | |
x86, irq: Use 0x20 for the IRQ_MOVE_CLEANUP_VECTOR instead of 0x1f
After talking to some more folks inside intel (Peter Anvin, Asit Mallick),
the safest option (for future compatibility etc) seen was to use vector 0x20
for IRQ_MOVE_CLEANUP_VECTOR instead of using vector 0x1f (which is documented as
reserved vector in the Intel IA32 manuals).
Also we don't need to reserve the entire privilege level (all 16 vectors in
the priority bucket that IRQ_MOVE_CLEANUP_VECTOR falls into), as the
x86 architecture (section 10.9.3 in SDM Vol3a) specifies that with in the
priority level, the higher the vector number the higher the priority.
And hence we don't need to reserve the complete priority level 0x20-0x2f for
the IRQ migration cleanup logic.
So change the IRQ_MOVE_CLEANUP_VECTOR to 0x20 and allow 0x21-0x2f to be used
for device interrupts. 0x30-0x3f will be used for ISA interrupts (these
also can be migrated in the context of IOAPIC and hence need to be at a higher
priority level than IRQ_MOVE_CLEANUP_VECTOR).
Signed-off-by: Suresh Siddha <suresh.b.siddha@intel.com>
LKML-Reference: <20100114002118.521826763@sbs-t61.sc.intel.com>
Cc: Yinghai Lu <yinghai@kernel.org>
Cc: Eric W. Biederman <ebiederm@xmission.com>
Cc: Maciej W. Rozycki <macro@linux-mips.org>
Signed-off-by: H. Peter Anvin <hpa@zytor.com>
Diffstat (limited to 'arch/x86/kernel')
| -rw-r--r-- | arch/x86/kernel/apic/io_apic.c | 4 |
1 files changed, 2 insertions, 2 deletions
diff --git a/arch/x86/kernel/apic/io_apic.c b/arch/x86/kernel/apic/io_apic.c index e9ba0903e9d5..409f4943dc1a 100644 --- a/arch/x86/kernel/apic/io_apic.c +++ b/arch/x86/kernel/apic/io_apic.c @@ -1162,7 +1162,7 @@ __assign_irq_vector(int irq, struct irq_cfg *cfg, const struct cpumask *mask) * Also, we've got to be careful not to trash gate * 0x80, because int 0x80 is hm, kind of importantish. ;) */ - static int current_vector = FIRST_DEVICE_VECTOR + VECTOR_OFFSET_START; + static int current_vector = FIRST_EXTERNAL_VECTOR + VECTOR_OFFSET_START; static int current_offset = VECTOR_OFFSET_START % 8; unsigned int old_vector; int cpu, err; @@ -1199,7 +1199,7 @@ next: if (vector >= first_system_vector) { /* If out of vectors on large boxen, must share them. */ offset = (offset + 1) % 8; - vector = FIRST_DEVICE_VECTOR + offset; + vector = FIRST_EXTERNAL_VECTOR + offset; } if (unlikely(current_vector == vector)) continue; |
