cpumask: allow disabling obsolete cpumask functions on x86

It currently depends on CONFIG_BROKEN; change to CONFIG_X86 (the
only platform which offers CPUMASK_OFFSTACK, so the only place
where it's really important).

We also complete it: the header shouldn't refer to the deprected
CPU_MASK_LAST_WORD, and the implementations are removed.

Signed-off-by: Rusty Russell <rusty@rustcorp.com.au>
---
 include/linux/cpumask.h |    4 ++--
 include/linux/sched.h   |    2 +-
 lib/Kconfig             |    4 +++-
 lib/cpumask.c           |    2 ++
 4 files changed, 8 insertions(+), 4 deletions(-)

diff --git a/include/linux/cpumask.h b/include/linux/cpumask.h
--- a/include/linux/cpumask.h
+++ b/include/linux/cpumask.h
@@ -700,7 +700,7 @@ static inline const struct cpumask *get_
 #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 */
@@ -708,7 +708,7 @@ static inline const struct cpumask *get_
 #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/include/linux/sched.h b/include/linux/sched.h
--- a/include/linux/sched.h
+++ b/include/linux/sched.h
@@ -1823,7 +1823,7 @@ static inline int set_cpus_allowed_ptr(s
 }
 #endif
 
-#ifndef CONFIG_CPUMASK_OFFSTACK
+#if !defined(CONFIG_CPUMASK_OFFSTACK) && !defined(CONFIG_DISABLE_OBSOLETE_CPUMASK_FUNCTIONS)
 static inline int set_cpus_allowed(struct task_struct *p, cpumask_t new_mask)
 {
 	return set_cpus_allowed_ptr(p, &new_mask);
diff --git a/lib/Kconfig b/lib/Kconfig
--- a/lib/Kconfig
+++ b/lib/Kconfig
@@ -186,7 +186,9 @@ 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.
 
 #
 # Netlink attribute parsing support is select'ed if needed
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