x86: use specialized routine for setup per-cpu area

We use the same routing as x86_64, moved now to setup.c.
Just with a few ifdefs inside.
Note that this routing uses prefill_possible_map().
It has the very nice side effect of allowing hotplugging of
cpus that are marked as present but disabled by acpi bios.

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

5 files changed, 107 insertions, 79 deletions

diff --git a/arch/x86/Kconfig b/arch/x86/Kconfig
index dbdd3142215c..fd27048087b8 100644
--- a/arch/x86/Kconfig
+++ b/arch/x86/Kconfig
@@ -117,7 +117,7 @@ config ARCH_HAS_CPU_RELAX
         def_bool y
 
 config HAVE_SETUP_PER_CPU_AREA
-        def_bool X86_64
+        def_bool X86_64 || (X86_SMP && !X86_VOYAGER)
 
 config ARCH_HIBERNATION_POSSIBLE
         def_bool y
diff --git a/arch/x86/kernel/Makefile b/arch/x86/kernel/Makefile
index c436e747f502..5d33509fd1c1 100644
--- a/arch/x86/kernel/Makefile
+++ b/arch/x86/kernel/Makefile
@@ -18,7 +18,7 @@ CFLAGS_tsc_64.o		:= $(nostackp)
 obj-y                   := process_$(BITS).o signal_$(BITS).o entry_$(BITS).o
 obj-y                   += traps_$(BITS).o irq_$(BITS).o
 obj-y                   += time_$(BITS).o ioport.o ldt.o
-obj-y                   += setup_$(BITS).o i8259_$(BITS).o
+obj-y                   += setup_$(BITS).o i8259_$(BITS).o setup.o
 obj-$(CONFIG_X86_32)    += sys_i386_32.o i386_ksyms_32.o
 obj-$(CONFIG_X86_64)    += sys_x86_64.o x8664_ksyms_64.o
 obj-$(CONFIG_X86_64)    += syscall_64.o vsyscall_64.o setup64.o
diff --git a/arch/x86/kernel/setup.c b/arch/x86/kernel/setup.c
new file mode 100644
index 000000000000..1179aa06cdbf
--- /dev/null
+++ b/arch/x86/kernel/setup.c
@@ -0,0 +1,103 @@
+#include <linux/kernel.h>
+#include <linux/module.h>
+#include <linux/init.h>
+#include <linux/bootmem.h>
+#include <linux/percpu.h>
+#include <asm/smp.h>
+#include <asm/percpu.h>
+#include <asm/sections.h>
+#include <asm/processor.h>
+#include <asm/setup.h>
+#include <asm/topology.h>
+
+#ifdef CONFIG_HAVE_SETUP_PER_CPU_AREA
+/*
+ * Copy data used in early init routines from the initial arrays to the
+ * per cpu data areas.  These arrays then become expendable and the
+ * *_early_ptr's are zeroed indicating that the static arrays are gone.
+ */
+static void __init setup_per_cpu_maps(void)
+{
+        int cpu;
+
+        for_each_possible_cpu(cpu) {
+#ifdef CONFIG_SMP
+                if (per_cpu_offset(cpu)) {
+#endif
+                        per_cpu(x86_cpu_to_apicid, cpu) =
+                                                x86_cpu_to_apicid_init[cpu];
+                        per_cpu(x86_bios_cpu_apicid, cpu) =
+                                                x86_bios_cpu_apicid_init[cpu];
+#ifdef CONFIG_NUMA
+                        per_cpu(x86_cpu_to_node_map, cpu) =
+                                                x86_cpu_to_node_map_init[cpu];
+#endif
+#ifdef CONFIG_SMP
+                } else
+                        printk(KERN_NOTICE "per_cpu_offset zero for cpu %d\n",
+                                                                        cpu);
+#endif
+        }
+
+        /* indicate the early static arrays will soon be gone */
+        x86_cpu_to_apicid_early_ptr = NULL;
+        x86_bios_cpu_apicid_early_ptr = NULL;
+#ifdef CONFIG_NUMA
+        x86_cpu_to_node_map_early_ptr = NULL;
+#endif
+}
+
+#ifdef CONFIG_X86_32
+/*
+ * Great future not-so-futuristic plan: make i386 and x86_64 do it
+ * the same way
+ */
+unsigned long __per_cpu_offset[NR_CPUS] __read_mostly;
+EXPORT_SYMBOL(__per_cpu_offset);
+#endif
+
+/*
+ * Great future plan:
+ * Declare PDA itself and support (irqstack,tss,pgd) as per cpu data.
+ * Always point %gs to its beginning
+ */
+void __init setup_per_cpu_areas(void)
+{
+        int i;
+        unsigned long size;
+
+#ifdef CONFIG_HOTPLUG_CPU
+        prefill_possible_map();
+#endif
+
+        /* Copy section for each CPU (we discard the original) */
+        size = PERCPU_ENOUGH_ROOM;
+
+        printk(KERN_INFO "PERCPU: Allocating %lu bytes of per cpu data\n",
+                          size);
+        for_each_cpu_mask(i, cpu_possible_map) {
+                char *ptr;
+#ifndef CONFIG_NEED_MULTIPLE_NODES
+                ptr = alloc_bootmem_pages(size);
+#else
+                int node = early_cpu_to_node(i);
+                if (!node_online(node) || !NODE_DATA(node))
+                        ptr = alloc_bootmem_pages(size);
+                else
+                        ptr = alloc_bootmem_pages_node(NODE_DATA(node), size);
+#endif
+                if (!ptr)
+                        panic("Cannot allocate cpu data for CPU %d\n", i);
+#ifdef CONFIG_X86_64
+                cpu_pda(i)->data_offset = ptr - __per_cpu_start;
+#else
+                __per_cpu_offset[i] = ptr - __per_cpu_start;
+#endif
+                memcpy(ptr, __per_cpu_start, __per_cpu_end - __per_cpu_start);
+        }
+
+        /* setup percpu data maps early */
+        setup_per_cpu_maps();
+}
+
+#endif
diff --git a/arch/x86/kernel/setup64.c b/arch/x86/kernel/setup64.c
index e24c45677094..6b4e3262e8cb 100644
--- a/arch/x86/kernel/setup64.c
+++ b/arch/x86/kernel/setup64.c
@@ -85,83 +85,6 @@ static int __init nonx32_setup(char *str)
 }
 __setup("noexec32=", nonx32_setup);
 
-/*
- * Copy data used in early init routines from the initial arrays to the
- * per cpu data areas.  These arrays then become expendable and the
- * *_early_ptr's are zeroed indicating that the static arrays are gone.
- */
-static void __init setup_per_cpu_maps(void)
-{
-        int cpu;
-
-        for_each_possible_cpu(cpu) {
-#ifdef CONFIG_SMP
-                if (per_cpu_offset(cpu)) {
-#endif
-                        per_cpu(x86_cpu_to_apicid, cpu) =
-                                                x86_cpu_to_apicid_init[cpu];
-                        per_cpu(x86_bios_cpu_apicid, cpu) =
-                                                x86_bios_cpu_apicid_init[cpu];
-#ifdef CONFIG_NUMA
-                        per_cpu(x86_cpu_to_node_map, cpu) =
-                                                x86_cpu_to_node_map_init[cpu];
-#endif
-#ifdef CONFIG_SMP
-                }
-                else
-                        printk(KERN_NOTICE "per_cpu_offset zero for cpu %d\n",
-                                                                        cpu);
-#endif
-        }
-
-        /* indicate the early static arrays will soon be gone */
-        x86_cpu_to_apicid_early_ptr = NULL;
-        x86_bios_cpu_apicid_early_ptr = NULL;
-#ifdef CONFIG_NUMA
-        x86_cpu_to_node_map_early_ptr = NULL;
-#endif
-}
-
-/*
- * Great future plan:
- * Declare PDA itself and support (irqstack,tss,pgd) as per cpu data.
- * Always point %gs to its beginning
- */
-void __init setup_per_cpu_areas(void)
-{ 
-        int i;
-        unsigned long size;
-
-#ifdef CONFIG_HOTPLUG_CPU
-        prefill_possible_map();
-#endif
-
-        /* Copy section for each CPU (we discard the original) */
-        size = PERCPU_ENOUGH_ROOM;
-
-        printk(KERN_INFO "PERCPU: Allocating %lu bytes of per cpu data\n", size);
-        for_each_cpu_mask (i, cpu_possible_map) {
-                char *ptr;
-#ifndef CONFIG_NEED_MULTIPLE_NODES
-                ptr = alloc_bootmem_pages(size);
-#else
-                int node = early_cpu_to_node(i);
-
-                if (!node_online(node) || !NODE_DATA(node))
-                        ptr = alloc_bootmem_pages(size);
-                else
-                        ptr = alloc_bootmem_pages_node(NODE_DATA(node), size);
-#endif
-                if (!ptr)
-                        panic("Cannot allocate cpu data for CPU %d\n", i);
-                cpu_pda(i)->data_offset = ptr - __per_cpu_start;
-                memcpy(ptr, __per_cpu_start, __per_cpu_end - __per_cpu_start);
-        }
-
-        /* setup percpu data maps early */
-        setup_per_cpu_maps();
-} 
-
 void pda_init(int cpu)
 { 
         struct x8664_pda *pda = cpu_pda(cpu);
diff --git a/arch/x86/kernel/smpboot_32.c b/arch/x86/kernel/smpboot_32.c
index 92a5df6190b5..bf5c9e9f26c1 100644
--- a/arch/x86/kernel/smpboot_32.c
+++ b/arch/x86/kernel/smpboot_32.c
@@ -665,6 +665,7 @@ static int __cpuinit do_boot_cpu(int apicid, int cpu)
                 unmap_cpu_to_logical_apicid(cpu);
                 cpu_clear(cpu, cpu_callout_map); /* was set here (do_boot_cpu()) */
                 cpu_clear(cpu, cpu_initialized); /* was set by cpu_init() */
+                cpu_clear(cpu, cpu_possible_map);
                 cpucount--;
         } else {
                 per_cpu(x86_cpu_to_apicid, cpu) = apicid;
@@ -743,6 +744,7 @@ EXPORT_SYMBOL(xquad_portio);
 
 static void __init disable_smp(void)
 {
+        cpu_possible_map = cpumask_of_cpu(0);
         smpboot_clear_io_apic_irqs();
         phys_cpu_present_map = physid_mask_of_physid(0);
         map_cpu_to_logical_apicid();