x86: unify setup_trampoline

setup_trampoline() looks very similar between architectures, and this
patch unifies them. The i386 version allocates bootmem memory, while
the x86_64 version uses a fixed address.

In this patch, we initialize the global trampoline_base to the x86_64 version,
and i386 allocation can later override it.

Signed-off-by: Glauber Costa <gcosta@redhat.com>
Signed-off-by: Ingo Molnar <mingo@elte.hu>

2 files changed, 4 insertions, 2 deletions

diff --git a/include/asm-x86/smp.h b/include/asm-x86/smp.h
index b2a1697e4700..513c8571a4a0 100644
--- a/include/asm-x86/smp.h
+++ b/include/asm-x86/smp.h
@@ -14,6 +14,7 @@ extern unsigned int num_processors;
  */
 extern const unsigned char trampoline_data [];
 extern const unsigned char trampoline_end  [];
+extern unsigned char *trampoline_base;
 
 struct smp_ops {
         void (*smp_prepare_boot_cpu)(void);
@@ -81,6 +82,9 @@ extern void __cpu_die(unsigned int cpu);
 
 extern unsigned disabled_cpus;
 extern void prefill_possible_map(void);
+
+#define SMP_TRAMPOLINE_BASE 0x6000
+extern unsigned long setup_trampoline(void);
 #endif
 
 #ifdef CONFIG_X86_32
diff --git a/include/asm-x86/smp_64.h b/include/asm-x86/smp_64.h
index d554d7d57327..394c78524331 100644
--- a/include/asm-x86/smp_64.h
+++ b/include/asm-x86/smp_64.h
@@ -40,8 +40,6 @@ static inline int cpu_present_to_apicid(int mps_cpu)
 
 #ifdef CONFIG_SMP
 
-#define SMP_TRAMPOLINE_BASE 0x6000
-
 #define raw_smp_processor_id()  read_pda(cpunumber)
 #define cpu_physical_id(cpu)    per_cpu(x86_cpu_to_apicid, cpu)