5 files changed, 21 insertions, 37 deletions

diff --git a/arch/x86/machine/cpu.c b/arch/x86/machine/cpu.c
index 0f362527..7e729d72 100644
--- a/arch/x86/machine/cpu.c
+++ b/arch/x86/machine/cpu.c
@@ -495,31 +495,6 @@ cpu_info(const struct cpu *cpu)
 }
 
 void __init
-cpu_fixup_bsp_percpu_area(void)
-{
-    struct cpu_pseudo_desc gdtr;
-    struct cpu *cpu;
-    void *pcpu_area;
-
-    /*
-     * It's important to use the percpu interface here, and not the cpu_local
-     * accessors : this function updates the GDTR (and the GDT on i386), as a
-     * result it must reference the future version of the GDT from the newly
-     * allocated percpu area.
-     */
-    cpu = percpu_ptr(cpu_desc, 0);
-    pcpu_area = percpu_area(0);
-
-#ifndef __LP64__
-    cpu_seg_set_data(cpu->gdt, CPU_GDT_SEL_PERCPU, (unsigned long)pcpu_area);
-#endif /* __LP64__ */
-
-    cpu_init_gdtr(&gdtr, cpu);
-    cpu_load_gdt(&gdtr);
-    cpu_set_percpu_area(cpu, pcpu_area);
-}
-
-void __init
 cpu_mp_register_lapic(unsigned int apic_id, int is_bsp)
 {
     struct cpu *cpu;
diff --git a/arch/x86/machine/cpu.h b/arch/x86/machine/cpu.h
index 52a2af03..9b6b028e 100644
--- a/arch/x86/machine/cpu.h
+++ b/arch/x86/machine/cpu.h
@@ -593,12 +593,6 @@ void cpu_check(const struct cpu *cpu);
 void cpu_info(const struct cpu *cpu);
 
 /*
- * Notify the cpu module that the true percpu area for the BSP has been
- * created.
- */
-void cpu_fixup_bsp_percpu_area(void);
-
-/*
  * Register the presence of a local APIC.
  */
 void cpu_mp_register_lapic(unsigned int apic_id, int is_bsp);
diff --git a/kern/kernel.c b/kern/kernel.c
index e5469079..069649de 100644
--- a/kern/kernel.c
+++ b/kern/kernel.c
@@ -19,6 +19,7 @@
 #include <kern/init.h>
 #include <kern/kernel.h>
 #include <kern/llsync.h>
+#include <kern/percpu.h>
 #include <kern/task.h>
 #include <kern/thread.h>
 #include <kern/work.h>
@@ -34,6 +35,7 @@ kernel_main(void)
 {
     assert(!cpu_intr_enabled());
 
+    percpu_cleanup();
     cpumap_setup();
     task_setup();
     thread_setup();
diff --git a/kern/percpu.c b/kern/percpu.c
index aab9d064..9a0bdf31 100644
--- a/kern/percpu.c
+++ b/kern/percpu.c
@@ -30,6 +30,7 @@
 
 void *percpu_areas[MAX_CPUS] __read_mostly;
 
+static void *percpu_area_content __initdata;
 static size_t percpu_size __initdata;
 static int percpu_skip_warning __initdata;
 
@@ -55,11 +56,10 @@ percpu_setup(void)
     va = vm_kmem_alloc(percpu_size);
 
     if (va == 0)
-        panic("percpu: unable to allocate percpu area for BSP");
+        panic("percpu: unable to allocate memory for percpu area content");
 
-    percpu_areas[0] = (void *)va;
-    memcpy(percpu_area(0), &_percpu, percpu_size);
-    cpu_fixup_bsp_percpu_area();
+    percpu_area_content = (void *)va;
+    memcpy(percpu_area_content, &_percpu, percpu_size);
 }
 
 int __init
@@ -93,8 +93,14 @@ percpu_add(unsigned int cpu)
     }
 
     percpu_areas[cpu] = (void *)va;
-    memcpy(percpu_area(cpu), &_percpu, percpu_size);
+    memcpy(percpu_area(cpu), percpu_area_content, percpu_size);
 
 out:
     return 0;
 }
+
+void
+percpu_cleanup(void)
+{
+    vm_kmem_free((unsigned long)percpu_area_content, percpu_size);
+}
diff --git a/kern/percpu.h b/kern/percpu.h
index 3492c6d8..46d33ed7 100644
--- a/kern/percpu.h
+++ b/kern/percpu.h
@@ -101,7 +101,9 @@ void percpu_bootstrap(void);
 /*
  * Complete initialization of the percpu module.
  *
- * Stop using the percpu section as the percpu area of the BSP.
+ * The BSP keeps using the percpu section, but its content is copied to a
+ * dedicated block of memory used as a template for subsequently added
+ * processors.
  */
 void percpu_setup(void);
 
@@ -114,4 +116,9 @@ void percpu_setup(void);
  */
 int percpu_add(unsigned int cpu);
 
+/*
+ * Release init data allocated for setup.
+ */
+void percpu_cleanup(void);
+
 #endif /* _KERN_PERCPU_H */