i386: introduce "used_vectors" bitmap which can be used to reserve vectors.
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).
[ tglx: arch/x86 adaptation ]
Signed-off-by: Rusty Russell <rusty@rustcorp.com.au>
Signed-off-by: Andi Kleen <ak@suse.de>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
diff --git a/arch/x86/kernel/i8259_32.c b/arch/x86/kernel/i8259_32.c
index d34a10c..f634fc7 100644
--- a/arch/x86/kernel/i8259_32.c
+++ b/arch/x86/kernel/i8259_32.c
@@ -403,7 +403,8 @@
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]);
}
diff --git a/arch/x86/kernel/io_apic_32.c b/arch/x86/kernel/io_apic_32.c
index 5f10c71..0c55e9d 100644
--- 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 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 @@
}
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;
@@ -2295,6 +2292,12 @@
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)
diff --git a/arch/x86/kernel/traps_32.c b/arch/x86/kernel/traps_32.c
index 3f02e0f..47e6d10 100644
--- a/arch/x86/kernel/traps_32.c
+++ b/arch/x86/kernel/traps_32.c
@@ -63,6 +63,9 @@
int panic_on_unrecovered_nmi;
+DECLARE_BITMAP(used_vectors, NR_VECTORS);
+EXPORT_SYMBOL_GPL(used_vectors);
+
asmlinkage int system_call(void);
/* Do we ignore FPU interrupts ? */
@@ -1120,6 +1123,8 @@
void __init trap_init(void)
{
+ int i;
+
#ifdef CONFIG_EISA
void __iomem *p = ioremap(0x0FFFD9, 4);
if (readl(p) == 'E'+('I'<<8)+('S'<<16)+('A'<<24)) {
@@ -1179,6 +1184,11 @@
set_system_gate(SYSCALL_VECTOR,&system_call);
+ /* Reserve all the builtin and the syscall vector. */
+ for (i = 0; i < FIRST_EXTERNAL_VECTOR; i++)
+ set_bit(i, used_vectors);
+ set_bit(SYSCALL_VECTOR, used_vectors);
+
/*
* Should be a barrier for any external CPU state.
*/