introduce and use nr_cpu_ids and nr_cpumask_bits

The former is the runtime equivalent of NR_CPUS (and users of NR_CPUS,
where necessary, get adjusted accordingly), while the latter is for the
sole use of determining the allocation size when dynamically allocating
CPU masks (done later in this series).

Adjust accessors to use either of the two to bound their bitmap
operations - which one gets used depends on whether accessing the bits
in the gap between nr_cpu_ids and nr_cpumask_bits is benign but more
efficient.

Signed-off-by: Jan Beulich <jbeulich@suse.com>
Acked-by: Keir Fraser <keir@xen.org>

1 files changed, 2 insertions, 0 deletions

diff --git a/xen/include/asm-x86/setup.h b/xen/include/asm-x86/setup.h
index f7d6345eab..874b1a323e 100644
--- a/xen/include/asm-x86/setup.h
+++ b/xen/include/asm-x86/setup.h
@@ -20,6 +20,8 @@ int nsc_init_cpu(void);
 int centaur_init_cpu(void);
 int transmeta_init_cpu(void);
 
+void set_nr_cpu_ids(unsigned int max_cpus);
+
 void numa_initmem_init(unsigned long start_pfn, unsigned long end_pfn);
 void arch_init_memory(void);
 void subarch_init_memory(void);