cpumask: centralize cpu_online_map and cpu_possible_map
Impact: cleanup
Each SMP arch defines these themselves. Move them to a central
location.
Twists:
1) Some archs (m32, parisc, s390) set possible_map to all 1, so we add a
CONFIG_INIT_ALL_POSSIBLE for this rather than break them.
2) mips and sparc32 '#define cpu_possible_map phys_cpu_present_map'.
Those archs simply have phys_cpu_present_map replaced everywhere.
3) Alpha defined cpu_possible_map to cpu_present_map; this is tricky
so I just manipulate them both in sync.
4) IA64, cris and m32r have gratuitous 'extern cpumask_t cpu_possible_map'
declarations.
Signed-off-by: Rusty Russell <rusty@rustcorp.com.au>
Reviewed-by: Grant Grundler <grundler@parisc-linux.org>
Tested-by: Tony Luck <tony.luck@intel.com>
Acked-by: Ingo Molnar <mingo@elte.hu>
Cc: Mike Travis <travis@sgi.com>
Cc: ink@jurassic.park.msu.ru
Cc: rmk@arm.linux.org.uk
Cc: starvik@axis.com
Cc: tony.luck@intel.com
Cc: takata@linux-m32r.org
Cc: ralf@linux-mips.org
Cc: grundler@parisc-linux.org
Cc: paulus@samba.org
Cc: schwidefsky@de.ibm.com
Cc: lethal@linux-sh.org
Cc: wli@holomorphy.com
Cc: davem@davemloft.net
Cc: jdike@addtoit.com
Cc: mingo@redhat.com
diff --git a/arch/alpha/include/asm/smp.h b/arch/alpha/include/asm/smp.h
index 544c69a..547e909 100644
--- a/arch/alpha/include/asm/smp.h
+++ b/arch/alpha/include/asm/smp.h
@@ -45,7 +45,6 @@
#define raw_smp_processor_id() (current_thread_info()->cpu)
extern int smp_num_cpus;
-#define cpu_possible_map cpu_present_map
extern void arch_send_call_function_single_ipi(int cpu);
extern void arch_send_call_function_ipi(cpumask_t mask);
diff --git a/arch/alpha/kernel/process.c b/arch/alpha/kernel/process.c
index 351407e..f238370 100644
--- a/arch/alpha/kernel/process.c
+++ b/arch/alpha/kernel/process.c
@@ -94,6 +94,7 @@
flags |= 0x00040000UL; /* "remain halted" */
*pflags = flags;
cpu_clear(cpuid, cpu_present_map);
+ cpu_clear(cpuid, cpu_possible_map);
halt();
}
#endif
@@ -120,6 +121,7 @@
#ifdef CONFIG_SMP
/* Wait for the secondaries to halt. */
cpu_clear(boot_cpuid, cpu_present_map);
+ cpu_clear(boot_cpuid, cpu_possible_map);
while (cpus_weight(cpu_present_map))
barrier();
#endif
diff --git a/arch/alpha/kernel/smp.c b/arch/alpha/kernel/smp.c
index cf7da10..d953e51 100644
--- a/arch/alpha/kernel/smp.c
+++ b/arch/alpha/kernel/smp.c
@@ -70,11 +70,6 @@
/* Set to a secondary's cpuid when it comes online. */
static int smp_secondary_alive __devinitdata = 0;
-/* Which cpus ids came online. */
-cpumask_t cpu_online_map;
-
-EXPORT_SYMBOL(cpu_online_map);
-
int smp_num_probed; /* Internal processor count */
int smp_num_cpus = 1; /* Number that came online. */
EXPORT_SYMBOL(smp_num_cpus);
@@ -440,6 +435,7 @@
((char *)cpubase + i*hwrpb->processor_size);
if ((cpu->flags & 0x1cc) == 0x1cc) {
smp_num_probed++;
+ cpu_set(i, cpu_possible_map);
cpu_set(i, cpu_present_map);
cpu->pal_revision = boot_cpu_palrev;
}
@@ -473,6 +469,7 @@
/* Nothing to do on a UP box, or when told not to. */
if (smp_num_probed == 1 || max_cpus == 0) {
+ cpu_possible_map = cpumask_of_cpu(boot_cpuid);
cpu_present_map = cpumask_of_cpu(boot_cpuid);
printk(KERN_INFO "SMP mode deactivated.\n");
return;
diff --git a/arch/arm/kernel/smp.c b/arch/arm/kernel/smp.c
index e42a749..bd905c0 100644
--- a/arch/arm/kernel/smp.c
+++ b/arch/arm/kernel/smp.c
@@ -34,16 +34,6 @@
#include <asm/ptrace.h>
/*
- * bitmask of present and online CPUs.
- * The present bitmask indicates that the CPU is physically present.
- * The online bitmask indicates that the CPU is up and running.
- */
-cpumask_t cpu_possible_map;
-EXPORT_SYMBOL(cpu_possible_map);
-cpumask_t cpu_online_map;
-EXPORT_SYMBOL(cpu_online_map);
-
-/*
* as from 2.5, kernels no longer have an init_tasks structure
* so we need some other way of telling a new secondary core
* where to place its SVC stack
diff --git a/arch/cris/arch-v32/kernel/smp.c b/arch/cris/arch-v32/kernel/smp.c
index 52e16c6..9dac173 100644
--- a/arch/cris/arch-v32/kernel/smp.c
+++ b/arch/cris/arch-v32/kernel/smp.c
@@ -29,11 +29,7 @@
spinlock_t cris_atomic_locks[] = { [0 ... LOCK_COUNT - 1] = SPIN_LOCK_UNLOCKED};
/* CPU masks */
-cpumask_t cpu_online_map = CPU_MASK_NONE;
-EXPORT_SYMBOL(cpu_online_map);
cpumask_t phys_cpu_present_map = CPU_MASK_NONE;
-cpumask_t cpu_possible_map;
-EXPORT_SYMBOL(cpu_possible_map);
EXPORT_SYMBOL(phys_cpu_present_map);
/* Variables used during SMP boot */
diff --git a/arch/cris/include/asm/smp.h b/arch/cris/include/asm/smp.h
index dba33ab..c615a06 100644
--- a/arch/cris/include/asm/smp.h
+++ b/arch/cris/include/asm/smp.h
@@ -4,7 +4,6 @@
#include <linux/cpumask.h>
extern cpumask_t phys_cpu_present_map;
-extern cpumask_t cpu_possible_map;
#define raw_smp_processor_id() (current_thread_info()->cpu)
diff --git a/arch/ia64/include/asm/smp.h b/arch/ia64/include/asm/smp.h
index 12d96e0..21c4023 100644
--- a/arch/ia64/include/asm/smp.h
+++ b/arch/ia64/include/asm/smp.h
@@ -57,7 +57,6 @@
extern char no_int_routing __devinitdata;
-extern cpumask_t cpu_online_map;
extern cpumask_t cpu_core_map[NR_CPUS];
DECLARE_PER_CPU(cpumask_t, cpu_sibling_map);
extern int smp_num_siblings;
diff --git a/arch/ia64/kernel/smpboot.c b/arch/ia64/kernel/smpboot.c
index 1dcbb85..4ede6e5 100644
--- a/arch/ia64/kernel/smpboot.c
+++ b/arch/ia64/kernel/smpboot.c
@@ -131,12 +131,6 @@
*/
DEFINE_PER_CPU(int, cpu_state);
-/* Bitmasks of currently online, and possible CPUs */
-cpumask_t cpu_online_map;
-EXPORT_SYMBOL(cpu_online_map);
-cpumask_t cpu_possible_map = CPU_MASK_NONE;
-EXPORT_SYMBOL(cpu_possible_map);
-
cpumask_t cpu_core_map[NR_CPUS] __cacheline_aligned;
EXPORT_SYMBOL(cpu_core_map);
DEFINE_PER_CPU_SHARED_ALIGNED(cpumask_t, cpu_sibling_map);
diff --git a/arch/m32r/Kconfig b/arch/m32r/Kconfig
index dbaed4a..17a6dab 100644
--- a/arch/m32r/Kconfig
+++ b/arch/m32r/Kconfig
@@ -10,6 +10,7 @@
default y
select HAVE_IDE
select HAVE_OPROFILE
+ select INIT_ALL_POSSIBLE
config SBUS
bool
diff --git a/arch/m32r/kernel/smpboot.c b/arch/m32r/kernel/smpboot.c
index 39cb6da..0f06b37 100644
--- a/arch/m32r/kernel/smpboot.c
+++ b/arch/m32r/kernel/smpboot.c
@@ -73,17 +73,11 @@
/* Bitmask of physically existing CPUs */
physid_mask_t phys_cpu_present_map;
-/* Bitmask of currently online CPUs */
-cpumask_t cpu_online_map;
-EXPORT_SYMBOL(cpu_online_map);
-
cpumask_t cpu_bootout_map;
cpumask_t cpu_bootin_map;
static cpumask_t cpu_callin_map;
cpumask_t cpu_callout_map;
EXPORT_SYMBOL(cpu_callout_map);
-cpumask_t cpu_possible_map = CPU_MASK_ALL;
-EXPORT_SYMBOL(cpu_possible_map);
/* Per CPU bogomips and other parameters */
struct cpuinfo_m32r cpu_data[NR_CPUS] __cacheline_aligned;
diff --git a/arch/mips/include/asm/smp.h b/arch/mips/include/asm/smp.h
index 0ff5b52..86557b5 100644
--- a/arch/mips/include/asm/smp.h
+++ b/arch/mips/include/asm/smp.h
@@ -38,9 +38,6 @@
#define SMP_RESCHEDULE_YOURSELF 0x1 /* XXX braindead */
#define SMP_CALL_FUNCTION 0x2
-extern cpumask_t phys_cpu_present_map;
-#define cpu_possible_map phys_cpu_present_map
-
extern void asmlinkage smp_bootstrap(void);
/*
diff --git a/arch/mips/kernel/smp-cmp.c b/arch/mips/kernel/smp-cmp.c
index ca476c4..6789c1a 100644
--- a/arch/mips/kernel/smp-cmp.c
+++ b/arch/mips/kernel/smp-cmp.c
@@ -226,7 +226,7 @@
for (i = 1; i < NR_CPUS; i++) {
if (amon_cpu_avail(i)) {
- cpu_set(i, phys_cpu_present_map);
+ cpu_set(i, cpu_possible_map);
__cpu_number_map[i] = ++ncpu;
__cpu_logical_map[ncpu] = i;
}
diff --git a/arch/mips/kernel/smp-mt.c b/arch/mips/kernel/smp-mt.c
index 87a1816..6f7ee5a 100644
--- a/arch/mips/kernel/smp-mt.c
+++ b/arch/mips/kernel/smp-mt.c
@@ -70,7 +70,7 @@
write_vpe_c0_vpeconf0(tmp);
/* Record this as available CPU */
- cpu_set(tc, phys_cpu_present_map);
+ cpu_set(tc, cpu_possible_map);
__cpu_number_map[tc] = ++ncpu;
__cpu_logical_map[ncpu] = tc;
}
diff --git a/arch/mips/kernel/smp.c b/arch/mips/kernel/smp.c
index 8bf88faf..3da9470 100644
--- a/arch/mips/kernel/smp.c
+++ b/arch/mips/kernel/smp.c
@@ -44,15 +44,10 @@
#include <asm/mipsmtregs.h>
#endif /* CONFIG_MIPS_MT_SMTC */
-cpumask_t phys_cpu_present_map; /* Bitmask of available CPUs */
volatile cpumask_t cpu_callin_map; /* Bitmask of started secondaries */
-cpumask_t cpu_online_map; /* Bitmask of currently online CPUs */
int __cpu_number_map[NR_CPUS]; /* Map physical to logical */
int __cpu_logical_map[NR_CPUS]; /* Map logical to physical */
-EXPORT_SYMBOL(phys_cpu_present_map);
-EXPORT_SYMBOL(cpu_online_map);
-
extern void cpu_idle(void);
/* Number of TCs (or siblings in Intel speak) per CPU core */
@@ -195,7 +190,7 @@
/* preload SMP state for boot cpu */
void __devinit smp_prepare_boot_cpu(void)
{
- cpu_set(0, phys_cpu_present_map);
+ cpu_set(0, cpu_possible_map);
cpu_set(0, cpu_online_map);
cpu_set(0, cpu_callin_map);
}
diff --git a/arch/mips/kernel/smtc.c b/arch/mips/kernel/smtc.c
index 897fb2b..b6cca01 100644
--- a/arch/mips/kernel/smtc.c
+++ b/arch/mips/kernel/smtc.c
@@ -290,7 +290,7 @@
* possibly leave some TCs/VPEs as "slave" processors.
*
* Use c0_MVPConf0 to find out how many TCs are available, setting up
- * phys_cpu_present_map and the logical/physical mappings.
+ * cpu_possible_map and the logical/physical mappings.
*/
int __init smtc_build_cpu_map(int start_cpu_slot)
@@ -304,7 +304,7 @@
*/
ntcs = ((read_c0_mvpconf0() & MVPCONF0_PTC) >> MVPCONF0_PTC_SHIFT) + 1;
for (i=start_cpu_slot; i<NR_CPUS && i<ntcs; i++) {
- cpu_set(i, phys_cpu_present_map);
+ cpu_set(i, cpu_possible_map);
__cpu_number_map[i] = i;
__cpu_logical_map[i] = i;
}
@@ -521,7 +521,7 @@
* Pull any physically present but unused TCs out of circulation.
*/
while (tc < (((val & MVPCONF0_PTC) >> MVPCONF0_PTC_SHIFT) + 1)) {
- cpu_clear(tc, phys_cpu_present_map);
+ cpu_clear(tc, cpu_possible_map);
cpu_clear(tc, cpu_present_map);
tc++;
}
diff --git a/arch/mips/pmc-sierra/yosemite/smp.c b/arch/mips/pmc-sierra/yosemite/smp.c
index 3a7df64..f78c29b 100644
--- a/arch/mips/pmc-sierra/yosemite/smp.c
+++ b/arch/mips/pmc-sierra/yosemite/smp.c
@@ -141,7 +141,7 @@
}
/*
- * Detect available CPUs, populate phys_cpu_present_map before smp_init
+ * Detect available CPUs, populate cpu_possible_map before smp_init
*
* We don't want to start the secondary CPU yet nor do we have a nice probing
* feature in PMON so we just assume presence of the secondary core.
@@ -150,10 +150,10 @@
{
int i;
- cpus_clear(phys_cpu_present_map);
+ cpus_clear(cpu_possible_map);
for (i = 0; i < 2; i++) {
- cpu_set(i, phys_cpu_present_map);
+ cpu_set(i, cpu_possible_map);
__cpu_number_map[i] = i;
__cpu_logical_map[i] = i;
}
diff --git a/arch/mips/sgi-ip27/ip27-smp.c b/arch/mips/sgi-ip27/ip27-smp.c
index ba5cdeb..5b47d6b 100644
--- a/arch/mips/sgi-ip27/ip27-smp.c
+++ b/arch/mips/sgi-ip27/ip27-smp.c
@@ -76,7 +76,7 @@
/* Only let it join in if it's marked enabled */
if ((acpu->cpu_info.flags & KLINFO_ENABLE) &&
(tot_cpus_found != NR_CPUS)) {
- cpu_set(cpuid, phys_cpu_present_map);
+ cpu_set(cpuid, cpu_possible_map);
alloc_cpupda(cpuid, tot_cpus_found);
cpus_found++;
tot_cpus_found++;
diff --git a/arch/mips/sibyte/bcm1480/smp.c b/arch/mips/sibyte/bcm1480/smp.c
index bd9eeb4..dddfda8 100644
--- a/arch/mips/sibyte/bcm1480/smp.c
+++ b/arch/mips/sibyte/bcm1480/smp.c
@@ -136,7 +136,7 @@
/*
* Use CFE to find out how many CPUs are available, setting up
- * phys_cpu_present_map and the logical/physical mappings.
+ * cpu_possible_map and the logical/physical mappings.
* XXXKW will the boot CPU ever not be physical 0?
*
* Common setup before any secondaries are started
@@ -145,14 +145,14 @@
{
int i, num;
- cpus_clear(phys_cpu_present_map);
- cpu_set(0, phys_cpu_present_map);
+ cpus_clear(cpu_possible_map);
+ cpu_set(0, cpu_possible_map);
__cpu_number_map[0] = 0;
__cpu_logical_map[0] = 0;
for (i = 1, num = 0; i < NR_CPUS; i++) {
if (cfe_cpu_stop(i) == 0) {
- cpu_set(i, phys_cpu_present_map);
+ cpu_set(i, cpu_possible_map);
__cpu_number_map[i] = ++num;
__cpu_logical_map[num] = i;
}
diff --git a/arch/mips/sibyte/sb1250/smp.c b/arch/mips/sibyte/sb1250/smp.c
index 0734b93..5950a28 100644
--- a/arch/mips/sibyte/sb1250/smp.c
+++ b/arch/mips/sibyte/sb1250/smp.c
@@ -124,7 +124,7 @@
/*
* Use CFE to find out how many CPUs are available, setting up
- * phys_cpu_present_map and the logical/physical mappings.
+ * cpu_possible_map and the logical/physical mappings.
* XXXKW will the boot CPU ever not be physical 0?
*
* Common setup before any secondaries are started
@@ -133,14 +133,14 @@
{
int i, num;
- cpus_clear(phys_cpu_present_map);
- cpu_set(0, phys_cpu_present_map);
+ cpus_clear(cpu_possible_map);
+ cpu_set(0, cpu_possible_map);
__cpu_number_map[0] = 0;
__cpu_logical_map[0] = 0;
for (i = 1, num = 0; i < NR_CPUS; i++) {
if (cfe_cpu_stop(i) == 0) {
- cpu_set(i, phys_cpu_present_map);
+ cpu_set(i, cpu_possible_map);
__cpu_number_map[i] = ++num;
__cpu_logical_map[num] = i;
}
diff --git a/arch/parisc/Kconfig b/arch/parisc/Kconfig
index 644a70b..aacf11d 100644
--- a/arch/parisc/Kconfig
+++ b/arch/parisc/Kconfig
@@ -11,6 +11,7 @@
select HAVE_OPROFILE
select RTC_CLASS
select RTC_DRV_PARISC
+ select INIT_ALL_POSSIBLE
help
The PA-RISC microprocessor is designed by Hewlett-Packard and used
in many of their workstations & servers (HP9000 700 and 800 series,
diff --git a/arch/parisc/kernel/smp.c b/arch/parisc/kernel/smp.c
index d47f397..80bc000 100644
--- a/arch/parisc/kernel/smp.c
+++ b/arch/parisc/kernel/smp.c
@@ -67,21 +67,6 @@
static int parisc_max_cpus __read_mostly = 1;
-/* online cpus are ones that we've managed to bring up completely
- * possible cpus are all valid cpu
- * present cpus are all detected cpu
- *
- * On startup we bring up the "possible" cpus. Since we discover
- * CPUs later, we add them as hotplug, so the possible cpu mask is
- * empty in the beginning.
- */
-
-cpumask_t cpu_online_map __read_mostly = CPU_MASK_NONE; /* Bitmap of online CPUs */
-cpumask_t cpu_possible_map __read_mostly = CPU_MASK_ALL; /* Bitmap of Present CPUs */
-
-EXPORT_SYMBOL(cpu_online_map);
-EXPORT_SYMBOL(cpu_possible_map);
-
DEFINE_PER_CPU(spinlock_t, ipi_lock) = SPIN_LOCK_UNLOCKED;
enum ipi_message_type {
diff --git a/arch/powerpc/kernel/smp.c b/arch/powerpc/kernel/smp.c
index ff9f701..d116556 100644
--- a/arch/powerpc/kernel/smp.c
+++ b/arch/powerpc/kernel/smp.c
@@ -60,13 +60,9 @@
int smp_hw_index[NR_CPUS];
struct thread_info *secondary_ti;
-cpumask_t cpu_possible_map = CPU_MASK_NONE;
-cpumask_t cpu_online_map = CPU_MASK_NONE;
DEFINE_PER_CPU(cpumask_t, cpu_sibling_map) = CPU_MASK_NONE;
DEFINE_PER_CPU(cpumask_t, cpu_core_map) = CPU_MASK_NONE;
-EXPORT_SYMBOL(cpu_online_map);
-EXPORT_SYMBOL(cpu_possible_map);
EXPORT_PER_CPU_SYMBOL(cpu_sibling_map);
EXPORT_PER_CPU_SYMBOL(cpu_core_map);
diff --git a/arch/s390/Kconfig b/arch/s390/Kconfig
index 8116a33..b4aa586 100644
--- a/arch/s390/Kconfig
+++ b/arch/s390/Kconfig
@@ -75,6 +75,7 @@
select HAVE_KRETPROBES
select HAVE_KVM if 64BIT
select HAVE_ARCH_TRACEHOOK
+ select INIT_ALL_POSSIBLE
source "init/Kconfig"
diff --git a/arch/s390/kernel/smp.c b/arch/s390/kernel/smp.c
index b559568..f03914b 100644
--- a/arch/s390/kernel/smp.c
+++ b/arch/s390/kernel/smp.c
@@ -52,12 +52,6 @@
struct _lowcore *lowcore_ptr[NR_CPUS];
EXPORT_SYMBOL(lowcore_ptr);
-cpumask_t cpu_online_map = CPU_MASK_NONE;
-EXPORT_SYMBOL(cpu_online_map);
-
-cpumask_t cpu_possible_map = CPU_MASK_ALL;
-EXPORT_SYMBOL(cpu_possible_map);
-
static struct task_struct *current_set[NR_CPUS];
static u8 smp_cpu_type;
diff --git a/arch/sh/kernel/smp.c b/arch/sh/kernel/smp.c
index 3c5ad16..593937d 100644
--- a/arch/sh/kernel/smp.c
+++ b/arch/sh/kernel/smp.c
@@ -31,12 +31,6 @@
int __cpu_number_map[NR_CPUS]; /* Map physical to logical */
int __cpu_logical_map[NR_CPUS]; /* Map logical to physical */
-cpumask_t cpu_possible_map;
-EXPORT_SYMBOL(cpu_possible_map);
-
-cpumask_t cpu_online_map;
-EXPORT_SYMBOL(cpu_online_map);
-
static inline void __init smp_store_cpu_info(unsigned int cpu)
{
struct sh_cpuinfo *c = cpu_data + cpu;
diff --git a/arch/sparc/include/asm/smp_32.h b/arch/sparc/include/asm/smp_32.h
index a8180e5..8408d9d 100644
--- a/arch/sparc/include/asm/smp_32.h
+++ b/arch/sparc/include/asm/smp_32.h
@@ -29,8 +29,6 @@
*/
extern unsigned char boot_cpu_id;
-extern cpumask_t phys_cpu_present_map;
-#define cpu_possible_map phys_cpu_present_map
typedef void (*smpfunc_t)(unsigned long, unsigned long, unsigned long,
unsigned long, unsigned long);
diff --git a/arch/sparc/kernel/smp.c b/arch/sparc/kernel/smp.c
index e396c1f..1e5ac4e 100644
--- a/arch/sparc/kernel/smp.c
+++ b/arch/sparc/kernel/smp.c
@@ -39,8 +39,6 @@
unsigned char boot_cpu_id = 0;
unsigned char boot_cpu_id4 = 0; /* boot_cpu_id << 2 */
-cpumask_t cpu_online_map = CPU_MASK_NONE;
-cpumask_t phys_cpu_present_map = CPU_MASK_NONE;
cpumask_t smp_commenced_mask = CPU_MASK_NONE;
/* The only guaranteed locking primitive available on all Sparc
@@ -334,7 +332,7 @@
instance = 0;
while (!cpu_find_by_instance(instance, NULL, &mid)) {
if (mid < NR_CPUS) {
- cpu_set(mid, phys_cpu_present_map);
+ cpu_set(mid, cpu_possible_map);
cpu_set(mid, cpu_present_map);
}
instance++;
@@ -354,7 +352,7 @@
current_thread_info()->cpu = cpuid;
cpu_set(cpuid, cpu_online_map);
- cpu_set(cpuid, phys_cpu_present_map);
+ cpu_set(cpuid, cpu_possible_map);
}
int __cpuinit __cpu_up(unsigned int cpu)
diff --git a/arch/sparc/kernel/sparc_ksyms.c b/arch/sparc/kernel/sparc_ksyms.c
index b0dfff8..32d11a5 100644
--- a/arch/sparc/kernel/sparc_ksyms.c
+++ b/arch/sparc/kernel/sparc_ksyms.c
@@ -113,10 +113,6 @@
#ifdef CONFIG_SMP
/* IRQ implementation. */
EXPORT_SYMBOL(synchronize_irq);
-
-/* CPU online map and active count. */
-EXPORT_SYMBOL(cpu_online_map);
-EXPORT_SYMBOL(phys_cpu_present_map);
#endif
EXPORT_SYMBOL(__udelay);
diff --git a/arch/sparc64/kernel/smp.c b/arch/sparc64/kernel/smp.c
index f500b06..a97b882 100644
--- a/arch/sparc64/kernel/smp.c
+++ b/arch/sparc64/kernel/smp.c
@@ -49,14 +49,10 @@
int sparc64_multi_core __read_mostly;
-cpumask_t cpu_possible_map __read_mostly = CPU_MASK_NONE;
-cpumask_t cpu_online_map __read_mostly = CPU_MASK_NONE;
DEFINE_PER_CPU(cpumask_t, cpu_sibling_map) = CPU_MASK_NONE;
cpumask_t cpu_core_map[NR_CPUS] __read_mostly =
{ [0 ... NR_CPUS-1] = CPU_MASK_NONE };
-EXPORT_SYMBOL(cpu_possible_map);
-EXPORT_SYMBOL(cpu_online_map);
EXPORT_PER_CPU_SYMBOL(cpu_sibling_map);
EXPORT_SYMBOL(cpu_core_map);
diff --git a/arch/um/kernel/smp.c b/arch/um/kernel/smp.c
index 0457721..98351c7 100644
--- a/arch/um/kernel/smp.c
+++ b/arch/um/kernel/smp.c
@@ -25,13 +25,6 @@
#include "irq_user.h"
#include "os.h"
-/* CPU online map, set by smp_boot_cpus */
-cpumask_t cpu_online_map = CPU_MASK_NONE;
-cpumask_t cpu_possible_map = CPU_MASK_NONE;
-
-EXPORT_SYMBOL(cpu_online_map);
-EXPORT_SYMBOL(cpu_possible_map);
-
/* Per CPU bogomips and other parameters
* The only piece used here is the ipi pipe, which is set before SMP is
* started and never changed.
diff --git a/arch/x86/kernel/smpboot.c b/arch/x86/kernel/smpboot.c
index 7b10933..468c2f9 100644
--- a/arch/x86/kernel/smpboot.c
+++ b/arch/x86/kernel/smpboot.c
@@ -101,14 +101,8 @@
/* Last level cache ID of each logical CPU */
DEFINE_PER_CPU(u16, cpu_llc_id) = BAD_APICID;
-/* bitmap of online cpus */
-cpumask_t cpu_online_map __read_mostly;
-EXPORT_SYMBOL(cpu_online_map);
-
cpumask_t cpu_callin_map;
cpumask_t cpu_callout_map;
-cpumask_t cpu_possible_map;
-EXPORT_SYMBOL(cpu_possible_map);
/* representing HT siblings of each logical CPU */
DEFINE_PER_CPU(cpumask_t, cpu_sibling_map);
diff --git a/arch/x86/mach-voyager/voyager_smp.c b/arch/x86/mach-voyager/voyager_smp.c
index 5214500..9c99018 100644
--- a/arch/x86/mach-voyager/voyager_smp.c
+++ b/arch/x86/mach-voyager/voyager_smp.c
@@ -63,11 +63,6 @@
/* Used for the invalidate map that's also checked in the spinlock */
static volatile unsigned long smp_invalidate_needed;
-/* Bitmask of currently online CPUs - used by setup.c for
- /proc/cpuinfo, visible externally but still physical */
-cpumask_t cpu_online_map = CPU_MASK_NONE;
-EXPORT_SYMBOL(cpu_online_map);
-
/* Bitmask of CPUs present in the system - exported by i386_syms.c, used
* by scheduler but indexed physically */
cpumask_t phys_cpu_present_map = CPU_MASK_NONE;
@@ -218,8 +213,6 @@
/* This is for the new dynamic CPU boot code */
cpumask_t cpu_callin_map = CPU_MASK_NONE;
cpumask_t cpu_callout_map = CPU_MASK_NONE;
-cpumask_t cpu_possible_map = CPU_MASK_NONE;
-EXPORT_SYMBOL(cpu_possible_map);
/* The per processor IRQ masks (these are usually kept in sync) */
static __u16 vic_irq_mask[NR_CPUS] __cacheline_aligned;
diff --git a/include/asm-m32r/smp.h b/include/asm-m32r/smp.h
index c5dd669..b96a6d2 100644
--- a/include/asm-m32r/smp.h
+++ b/include/asm-m32r/smp.h
@@ -63,8 +63,6 @@
#define raw_smp_processor_id() (current_thread_info()->cpu)
extern cpumask_t cpu_callout_map;
-extern cpumask_t cpu_possible_map;
-extern cpumask_t cpu_present_map;
static __inline__ int hard_smp_processor_id(void)
{
diff --git a/init/Kconfig b/init/Kconfig
index f763762..7656623 100644
--- a/init/Kconfig
+++ b/init/Kconfig
@@ -916,6 +916,15 @@
endif # MODULES
+config INIT_ALL_POSSIBLE
+ bool
+ help
+ Back when each arch used to define their own cpu_online_map and
+ cpu_possible_map, some of them chose to initialize cpu_possible_map
+ with all 1s, and others with all 0s. When they were centralised,
+ it was better to provide this option than to break all the archs
+ and have several arch maintainers persuing me down dark alleys.
+
config STOP_MACHINE
bool
default y
diff --git a/kernel/cpu.c b/kernel/cpu.c
index 8ea32e8..bae131a 100644
--- a/kernel/cpu.c
+++ b/kernel/cpu.c
@@ -24,19 +24,20 @@
cpumask_t cpu_present_map __read_mostly;
EXPORT_SYMBOL(cpu_present_map);
-#ifndef CONFIG_SMP
-
/*
* Represents all cpu's that are currently online.
*/
-cpumask_t cpu_online_map __read_mostly = CPU_MASK_ALL;
+cpumask_t cpu_online_map __read_mostly;
EXPORT_SYMBOL(cpu_online_map);
+#ifdef CONFIG_INIT_ALL_POSSIBLE
cpumask_t cpu_possible_map __read_mostly = CPU_MASK_ALL;
+#else
+cpumask_t cpu_possible_map __read_mostly;
+#endif
EXPORT_SYMBOL(cpu_possible_map);
-#else /* CONFIG_SMP */
-
+#ifdef CONFIG_SMP
/* Serializes the updates to cpu_online_map, cpu_present_map */
static DEFINE_MUTEX(cpu_add_remove_lock);
