x86: change FIRST_SYSTEM_VECTOR to a variable

The SGI UV system needs several more system vectors than a vanilla
x86_64 system.  Rather than burden the other archs with extra system
vectors that they don't use, change FIRST_SYSTEM_VECTOR to a variable,
so that it can be dynamic.

Signed-off-by: Alan Mayer <ajm@sgi.com>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>

1 files changed, 6 insertions, 2 deletions

diff --git a/arch/x86/kernel/io_apic_32.c b/arch/x86/kernel/io_apic_32.c
index a40d54fc1fdd..0ae4a9d00ce8 100644
--- a/arch/x86/kernel/io_apic_32.c
+++ b/arch/x86/kernel/io_apic_32.c
@@ -83,6 +83,10 @@ int mp_irq_entries;
 
 static int disable_timer_pin_1 __initdata;
 
+int first_system_vector = 0xfe;
+
+char system_vectors[NR_VECTORS] = { [0 ... NR_VECTORS-1] = SYS_VECTOR_FREE};
+
 /*
  * Rough estimation of how many shared IRQs there are, can
  * be changed anytime.
@@ -1176,7 +1180,7 @@ static int __assign_irq_vector(int irq)
         offset = current_offset;
 next:
         vector += 8;
-        if (vector >= FIRST_SYSTEM_VECTOR) {
+        if (vector >= first_system_vector) {
                 offset = (offset + 1) % 8;
                 vector = FIRST_DEVICE_VECTOR + offset;
         }
@@ -2269,7 +2273,7 @@ void __init setup_IO_APIC(void)
         int i;
 
         /* Reserve all the system vectors. */
-        for (i = FIRST_SYSTEM_VECTOR; i < NR_VECTORS; i++)
+        for (i = first_system_vector; i < NR_VECTORS; i++)
                 set_bit(i, used_vectors);
 
         enable_IO_APIC();