cpumask: allow disabling obsolete cpumask functions on x86

Since they only matter if you're relying on CPUMASK_OFFSTACK, and
only x86 supports that for now, make it depend on x86.

Turning it on is a nice way to check you converted them all.

Also, remove reference to CPU_MASK_LAST_WORD in cpumask.h, and
deprecated function definitions from cpumask.c.

Signed-off-by: Rusty Russell <rusty@rustcorp.com.au>
---
 include/linux/cpumask.h |    4 ++--
 lib/Kconfig             |    4 +++-
 lib/cpumask.c           |    2 ++
 3 files changed, 7 insertions(+), 3 deletions(-)

diff --git a/include/linux/cpumask.h b/include/linux/cpumask.h
--- a/include/linux/cpumask.h
+++ b/include/linux/cpumask.h
@@ -524,7 +524,7 @@ extern unsigned long __cpu_active_bits[]
 #if NR_CPUS <= BITS_PER_LONG
 #define CPU_BITS_ALL						\
 {								\
-	[BITS_TO_LONGS(NR_CPUS)-1] = CPU_MASK_LAST_WORD	\
+	[BITS_TO_LONGS(NR_CPUS)-1] = BITMAP_LAST_WORD_MASK(NR_CPUS)	\
 }
 
 #else /* NR_CPUS > BITS_PER_LONG */
@@ -532,7 +532,7 @@ extern unsigned long __cpu_active_bits[]
 #define CPU_BITS_ALL						\
 {								\
 	[0 ... BITS_TO_LONGS(NR_CPUS)-2] = ~0UL,		\
-	[BITS_TO_LONGS(NR_CPUS)-1] = CPU_MASK_LAST_WORD		\
+	[BITS_TO_LONGS(NR_CPUS)-1] = BITMAP_LAST_WORD_MASK(NR_CPUS)	\
 }
 #endif /* NR_CPUS > BITS_PER_LONG */
 
diff --git a/lib/Kconfig b/lib/Kconfig
--- a/lib/Kconfig
+++ b/lib/Kconfig
@@ -172,6 +172,8 @@ config CPUMASK_OFFSTACK
 
 config DISABLE_OBSOLETE_CPUMASK_FUNCTIONS
        bool "Disable obsolete cpumask functions" if DEBUG_PER_CPU_MAPS
-       depends on EXPERIMENTAL && BROKEN
+       depends on EXPERIMENTAL && X86
+       help
+	 Only x86 has been cleaned of obsolescent cpumask functions.
 
 endmenu
diff --git a/lib/cpumask.c b/lib/cpumask.c
--- a/lib/cpumask.c
+++ b/lib/cpumask.c
@@ -4,6 +4,7 @@
 #include <linux/module.h>
 #include <linux/bootmem.h>
 
+#ifndef CONFIG_DISABLE_OBSOLETE_CPUMASK_FUNCTIONS
 int __first_cpu(const cpumask_t *srcp)
 {
 	return min_t(int, NR_CPUS, find_first_bit(srcp->bits, NR_CPUS));
@@ -36,6 +37,7 @@ int __any_online_cpu(const cpumask_t *ma
 	return cpu;
 }
 EXPORT_SYMBOL(__any_online_cpu);
+#endif /* CONFIG_DISABLE_OBSOLETE_CPUMASK_FUNCTIONS */
 
 /**
  * cpumask_next_and - get the next cpu in *src1p & *src2p