This simplifies the io_apic.c __assign_irq_vector() logic and removes

the explicit SYSCALL_VECTOR check, and also allows for vectors to be

reserved by other mechanisms (ie. lguest).
Signed-off-by: Rusty Russell <rusty@rustcorp.com.au>

Signed-off-by: Andi Kleen <ak@suse.de>

---

 arch/x86/kernel/i8259_32.c   |    3 ++-

 arch/x86/kernel/io_apic_32.c |   13 ++++++++-----

 arch/x86/kernel/traps_32.c   |   10 ++++++++++

 include/asm-x86/irq_32.h     |    3 +++

 4 files changed, 23 insertions(+), 6 deletions(-)
===================================================================

--- a/arch/x86/kernel/i8259_32.c

+++ b/arch/x86/kernel/i8259_32.c

@@ -400,7 +400,8 @@ void __init native_init_IRQ(void)

 		int vector = FIRST_EXTERNAL_VECTOR + i;

 		if (i >= NR_IRQS)

 			break;

-		if (vector != SYSCALL_VECTOR)

+		/* SYSCALL_VECTOR was reserved in trap_init. */

+		if (!test_bit(vector, used_vectors))

 			set_intr_gate(vector, interrupt[i]);

 	}
===================================================================

--- a/arch/x86/kernel/io_apic_32.c

+++ b/arch/x86/kernel/io_apic_32.c

@@ -1198,7 +1198,7 @@ static int __assign_irq_vector(int irq)

 static int __assign_irq_vector(int irq)

 {

 	static int current_vector = FIRST_DEVICE_VECTOR, current_offset = 0;

-	int vector, offset, i;

+	int vector, offset;
 	BUG_ON((unsigned)irq >= NR_IRQ_VECTORS);
@@ -1215,11 +1215,8 @@ next:

 	}

 	if (vector == current_vector)

 		return -ENOSPC;

-	if (vector == SYSCALL_VECTOR)

+	if (test_and_set_bit(vector, used_vectors))

 		goto next;

-	for (i = 0; i < NR_IRQ_VECTORS; i++)

-		if (irq_vector[i] == vector)

-			goto next;
 	current_vector = vector;

 	current_offset = offset;

@@ -2290,6 +2287,12 @@ static inline void __init check_timer(vo
 void __init setup_IO_APIC(void)

 {

+	int i;

+

+	/* Reserve all the system vectors. */

+	for (i = FIRST_SYSTEM_VECTOR; i < NR_VECTORS; i++)

+		set_bit(i, used_vectors);

+

 	enable_IO_APIC();
 	if (acpi_ioapic)

========...
[ message continues ]

On Wed, 17 Oct 2007 20:56:04 +1000
I already have this one as

x86_64-mm-introduce-used_vectors-bitmap-which-can-be-used-to-reserve-vectors.patch

- part of the firstfloor tree.
Thomas is going through those patches and is getting them merged up - a large

batch went through today.
So I assume he'll me merging this patch via that route, unless he has

decided to skip it for some reason.
Either way, I guess I'll hang onto the firstfloor.org leftovers until each

one has some sort of definite disposition.
-

It's in the "needs review" batch and I push out a git branch with the

ones in our backlog when I'm done with picking up stuff here and there.
     tglx
-