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>
diff --git a/arch/x86/kernel/smpboot.c b/arch/x86/kernel/smpboot.c
index 34c3117..b13b9d5 100644
--- a/arch/x86/kernel/smpboot.c
+++ b/arch/x86/kernel/smpboot.c
@@ -3,6 +3,7 @@
#include <linux/module.h>
#include <linux/sched.h>
#include <linux/percpu.h>
+#include <linux/bootmem.h>
#include <asm/nmi.h>
#include <asm/irq.h>
@@ -38,6 +39,9 @@
DEFINE_PER_CPU_SHARED_ALIGNED(struct cpuinfo_x86, cpu_info);
EXPORT_PER_CPU_SYMBOL(cpu_info);
+/* ready for x86_64, no harm for x86, since it will overwrite after alloc */
+unsigned char *trampoline_base = __va(SMP_TRAMPOLINE_BASE);
+
/* representing cpus for which sibling maps can be computed */
static cpumask_t cpu_sibling_setup_map;
@@ -117,6 +121,35 @@
return c->llc_shared_map;
}
+/*
+ * Currently trivial. Write the real->protected mode
+ * bootstrap into the page concerned. The caller
+ * has made sure it's suitably aligned.
+ */
+
+unsigned long __cpuinit setup_trampoline(void)
+{
+ memcpy(trampoline_base, trampoline_data,
+ trampoline_end - trampoline_data);
+ return virt_to_phys(trampoline_base);
+}
+
+#ifdef CONFIG_X86_32
+/*
+ * We are called very early to get the low memory for the
+ * SMP bootup trampoline page.
+ */
+void __init smp_alloc_memory(void)
+{
+ trampoline_base = alloc_bootmem_low_pages(PAGE_SIZE);
+ /*
+ * Has to be in very low memory so we can execute
+ * real-mode AP code.
+ */
+ if (__pa(trampoline_base) >= 0x9F000)
+ BUG();
+}
+#endif
#ifdef CONFIG_HOTPLUG_CPU
void remove_siblinginfo(int cpu)