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

1 files changed, 9 insertions, 0 deletions

diff --git a/init/Kconfig b/init/Kconfig
index f763762d544..7656623f500 100644
--- a/init/Kconfig
+++ b/init/Kconfig
@@ -916,6 +916,15 @@ config KMOD
 
 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