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 d34a10cc13a7dbe4eba3b456ed5eeca83e7be526..f634fc715c99b455d3973645d4d16c3a80e13361 100644 (file)
--- a/arch/x86/kernel/i8259_32.c
+++ b/arch/x86/kernel/i8259_32.c
@@ -403,7 +403,8 @@ 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]);
        }
 

diff --git a/arch/x86/kernel/io_apic_32.c b/arch/x86/kernel/io_apic_32.c
index 5f10c7189534807fa2c6eddd2ef838e06c85d09f..0c55e9d86f6999854adec3452e3004c39eafd920 100644 (file)
--- a/arch/x86/kernel/io_apic_32.c
+++ b/arch/x86/kernel/io_apic_32.c
@@ -1198,7 +1198,7 @@ static u8 irq_vector[NR_IRQ_VECTORS] __read_mostly = { FIRST_DEVICE_VECTOR , 0 }
 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;
@@ -2295,6 +2292,12 @@ static inline void __init check_timer(void)
 
 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 3f02e0f42e6ac453eb745df77e0a96add680c545..47e6d10902fe88c031f3fbfbe786af363896aa49 100644 (file)
--- 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 @@ static void __init set_task_gate(unsigned int n, unsigned int gdt_entry)
 
 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 @@ void __init trap_init(void)
 
        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.
         */

diff --git a/include/asm-x86/irq_32.h b/include/asm-x86/irq_32.h
index 36f310632c49a8bdc174f04a70c92841f7276f79..aca9c96e8e6b04308fcf10ecd817a046b853de39 100644 (file)
--- a/include/asm-x86/irq_32.h
+++ b/include/asm-x86/irq_32.h
@@ -45,4 +45,7 @@ unsigned int do_IRQ(struct pt_regs *regs);
 void init_IRQ(void);
 void __init native_init_IRQ(void);
 
+/* Interrupt vector management */
+extern DECLARE_BITMAP(used_vectors, NR_VECTORS);
+
 #endif /* _ASM_IRQ_H */