[PATCH] i386: Allow to use GENERICARCH for UP kernels
There are some machines around (large xSeries or Unisys ES7000) that
need physical IO-APIC destination mode to access all of their IO
devices. This currently doesn't work in UP kernels as used in
distribution installers.
This patch allows to compile even UP kernels as GENERICARCH which
allows to use physical or clustered APIC mode.
Signed-off-by: Andi Kleen <ak@suse.de>
diff --git a/include/asm-i386/mach-summit/mach_apic.h b/include/asm-i386/mach-summit/mach_apic.h
index 9fd0732..a81b059 100644
--- a/include/asm-i386/mach-summit/mach_apic.h
+++ b/include/asm-i386/mach-summit/mach_apic.h
@@ -46,10 +46,12 @@
static inline void init_apic_ldr(void)
{
unsigned long val, id;
- int i, count;
- u8 lid;
+ int count = 0;
u8 my_id = (u8)hard_smp_processor_id();
u8 my_cluster = (u8)apicid_cluster(my_id);
+#ifdef CONFIG_SMP
+ u8 lid;
+ int i;
/* Create logical APIC IDs by counting CPUs already in cluster. */
for (count = 0, i = NR_CPUS; --i >= 0; ) {
@@ -57,6 +59,7 @@
if (lid != BAD_APICID && apicid_cluster(lid) == my_cluster)
++count;
}
+#endif
/* We only have a 4 wide bitmap in cluster mode. If a deranged
* BIOS puts 5 CPUs in one APIC cluster, we're hosed. */
BUG_ON(count >= XAPIC_DEST_CPUS_SHIFT);
@@ -91,9 +94,13 @@
/* Mapping from cpu number to logical apicid */
static inline int cpu_to_logical_apicid(int cpu)
{
+#ifdef CONFIG_SMP
if (cpu >= NR_CPUS)
return BAD_APICID;
return (int)cpu_2_logical_apicid[cpu];
+#else
+ return logical_smp_processor_id();
+#endif
}
static inline int cpu_present_to_apicid(int mps_cpu)