cpumask: make cpumask_of_cpu_map generic

If an arch doesn't define cpumask_of_cpu_map, create a generic
statically-initialized one for them.  This allows removal of the buggy
cpumask_of_cpu() macro (&cpumask_of_cpu() gives address of
out-of-scope var).

An arch with NR_CPUS of 4096 probably wants to allocate this itself
based on the actual number of CPUs, since otherwise they're using 2MB
of rodata (1024 cpus means 128k).  That's what
CONFIG_HAVE_CPUMASK_OF_CPU_MAP is for (only x86/64 does so at the
moment).

In future as we support more CPUs, we'll need to resort to a
get_cpu_map()/put_cpu_map() allocation scheme.

Signed-off-by: Mike Travis <travis@sgi.com>
Signed-off-by: Rusty Russell <rusty@rustcorp.com.au>
Cc: Andrew Morton <akpm@linux-foundation.org>
Cc: Jack Steiner <steiner@sgi.com>
Signed-off-by: Ingo Molnar <mingo@elte.hu>

1 files changed, 3 insertions, 38 deletions

diff --git a/include/linux/cpumask.h b/include/linux/cpumask.h
index 1b5c98e7fef7..8fa3b6d4a320 100644
--- a/include/linux/cpumask.h
+++ b/include/linux/cpumask.h
@@ -62,15 +62,7 @@
  * int next_cpu_nr(cpu, mask)           Next cpu past 'cpu', or nr_cpu_ids
  *
  * cpumask_t cpumask_of_cpu(cpu)        Return cpumask with bit 'cpu' set
- *ifdef CONFIG_HAS_CPUMASK_OF_CPU
- * cpumask_of_cpu_ptr_declare(v)        Declares cpumask_t *v
- * cpumask_of_cpu_ptr_next(v, cpu)      Sets v = &cpumask_of_cpu_map[cpu]
- * cpumask_of_cpu_ptr(v, cpu)           Combines above two operations
- *else
- * cpumask_of_cpu_ptr_declare(v)        Declares cpumask_t _v and *v = &_v
- * cpumask_of_cpu_ptr_next(v, cpu)      Sets _v = cpumask_of_cpu(cpu)
- * cpumask_of_cpu_ptr(v, cpu)           Combines above two operations
- *endif
+ *                                      (can be used as an lvalue)
  * CPU_MASK_ALL                         Initializer - all bits set
  * CPU_MASK_NONE                        Initializer - no bits set
  * unsigned long *cpus_addr(mask)       Array of unsigned long's in mask
@@ -274,36 +266,9 @@ static inline void __cpus_shift_left(cpumask_t *dstp,
 }
 
 
-#ifdef CONFIG_HAVE_CPUMASK_OF_CPU_MAP
-extern cpumask_t *cpumask_of_cpu_map;
+/* cpumask_of_cpu_map[] is in kernel/cpu.c */
+extern const cpumask_t *cpumask_of_cpu_map;
 #define cpumask_of_cpu(cpu)     (cpumask_of_cpu_map[cpu])
-#define cpumask_of_cpu_ptr(v, cpu)                                      \
-                const cpumask_t *v = &cpumask_of_cpu(cpu)
-#define cpumask_of_cpu_ptr_declare(v)                                   \
-                const cpumask_t *v
-#define cpumask_of_cpu_ptr_next(v, cpu)                                 \
-                                        v = &cpumask_of_cpu(cpu)
-#else
-#define cpumask_of_cpu(cpu)                                             \
-({                                                                      \
-        typeof(_unused_cpumask_arg_) m;                                 \
-        if (sizeof(m) == sizeof(unsigned long)) {                       \
-                m.bits[0] = 1UL<<(cpu);                                 \
-        } else {                                                        \
-                cpus_clear(m);                                          \
-                cpu_set((cpu), m);                                      \
-        }                                                               \
-        m;                                                              \
-})
-#define cpumask_of_cpu_ptr(v, cpu)                                      \
-                cpumask_t _##v = cpumask_of_cpu(cpu);                   \
-                const cpumask_t *v = &_##v
-#define cpumask_of_cpu_ptr_declare(v)                                   \
-                cpumask_t _##v;                                         \
-                const cpumask_t *v = &_##v
-#define cpumask_of_cpu_ptr_next(v, cpu)                                 \
-                                        _##v = cpumask_of_cpu(cpu)
-#endif
 
 #define CPU_MASK_LAST_WORD BITMAP_LAST_WORD_MASK(NR_CPUS)