ia64: on UP percpu variables are not small memory model
Tony says:
| The CONFIG_SMP=n path in ia64 makes quite radical changes ... rather
| than putting all the per-cpu stuff into the top 64K of address space
| and providing a per-cpu TLB mapping for that range to a different
| physical address ... it just makes all the per-cpu stuff link as ordinary
| variables in .data.
the new generic percpu code got confused about this as PER_CPU_ATTRIBUTES
was defined even on UP, so it picked up that small memory model - which
was not possible to get linked. The right fix is to only define that
on SMP. This resolved the build failures in my cross-compiling environment.
also link these variables into the .percpu section even on UP - some
assembly code has offset dependencies. (such as GET_IA64_MCA_DATA() in
arch/ia64/kernel/mca_asm.S)
Signed-off-by: Ingo Molnar <mingo@elte.hu>
Acked-by: Tony Luck <tony.luck@intel.com>
diff --git a/include/asm-ia64/percpu.h b/include/asm-ia64/percpu.h
index 26404b7..77f30b6 100644
--- a/include/asm-ia64/percpu.h
+++ b/include/asm-ia64/percpu.h
@@ -15,18 +15,20 @@
#include <linux/threads.h>
+#ifdef CONFIG_SMP
+
#ifdef HAVE_MODEL_SMALL_ATTRIBUTE
# define PER_CPU_ATTRIBUTES __attribute__((__model__ (__small__)))
#endif
-#ifdef CONFIG_SMP
-
#define __my_cpu_offset __ia64_per_cpu_var(local_per_cpu_offset)
extern void *per_cpu_init(void);
#else /* ! SMP */
+#define PER_CPU_ATTRIBUTES __attribute__((__section__(".data.percpu")))
+
#define per_cpu_init() (__phys_per_cpu_start)
#endif /* SMP */