[PATCH 3/3] xen/sched: Make cpu_nr_siblings() architecture-specific

[Hirokazu Takahashi <taka@xxxxxxxxxxxxx>]

Make cpu_nr_siblings() an architecture-specific function.
This patch provides the implementation for x86 and a common
version for Device Tree-based architectures.

Signed-off-by: Hirokazu Takahashi <taka@xxxxxxxxxxxxx>
---
 xen/arch/x86/include/asm/processor.h |  1 +
 xen/common/sched/credit2.c           | 23 +++++------------------
 xen/include/xen/cpu-topology.h       |  2 ++
 3 files changed, 8 insertions(+), 18 deletions(-)

diff --git a/xen/arch/x86/include/asm/processor.h 
b/xen/arch/x86/include/asm/processor.h
index 8ca6799a81..9758060129 100644
--- a/xen/arch/x86/include/asm/processor.h
+++ b/xen/arch/x86/include/asm/processor.h
@@ -106,6 +106,7 @@ extern void intel_init_arat(void);
 
 #define cpu_to_core(_cpu)   (cpu_data[_cpu].cpu_core_id)
 #define cpu_to_socket(_cpu) (cpu_data[_cpu].phys_proc_id)
+#define cpu_nr_siblings(_cpu) (cpu_data[_cpu].x86_num_siblings)
 
 unsigned int apicid_to_socket(unsigned int apicid);
 
diff --git a/xen/common/sched/credit2.c b/xen/common/sched/credit2.c
index dcce1e361f..2d93944824 100644
--- a/xen/common/sched/credit2.c
+++ b/xen/common/sched/credit2.c
@@ -29,22 +29,6 @@
 /* #define d2printk printk */
 #define d2printk(x...)
 
-/*
- * TODO: Abstract this properly, and figure out what Credit2 wants to do with
- *       the fact that x86_num_siblings doesn't even have the same meaning
- *       between x86 vendors.
- */
-static unsigned int cpu_nr_siblings(unsigned int cpu)
-{
-#ifdef CONFIG_X86
-    return cpu_data[cpu].x86_num_siblings;
-#elif CONFIG_DT_CPU_TOPOLOGY
-    return cpu_topology[cpu].num_siblings;
-#else
-    return 1;
-#endif
-}
-
 /*
  * Credit2 tracing events ("only" 512 available!). Check
  * include/public/trace.h for more details.
@@ -884,8 +868,11 @@ cpu_runqueue_match(const struct csched2_runqueue_data 
*rqd, unsigned int cpu)
  * Additional checks, to avoid separating siblings in different runqueues.
  * This deals with both Intel's HTs and AMD's CUs. An arch that does not have
  * any similar concept will just have cpu_nr_siblings() always return 1, and
- * setup the cpu_sibling_mask-s acordingly (as currently does ARM), and things
- * will just work as well.
+ * setup the cpu_sibling_mask-s acordingly, and things will just work as well.
+ *
+ * TODO: Abstract cpu_nr_siblings properly, and figure out what Credit2 wants
+ *       to do with the fact that x86_num_siblings doesn't even have the same
+ *       meaning between x86 vendors.
  */
 static bool
 cpu_runqueue_siblings_match(const struct csched2_runqueue_data *rqd,
diff --git a/xen/include/xen/cpu-topology.h b/xen/include/xen/cpu-topology.h
index f268069449..ea5518bb16 100644
--- a/xen/include/xen/cpu-topology.h
+++ b/xen/include/xen/cpu-topology.h
@@ -25,6 +25,7 @@ void dt_init_cpu_topology(void);
 
 #define cpu_to_core(_cpu)   (cpu_topology[_cpu].phys_core_id)
 #define cpu_to_socket(_cpu)   (cpu_topology[_cpu].phys_socket_id)
+#define cpu_nr_siblings(_cpu) (cpu_topology[_cpu].num_siblings)
 
 #elif CONFIG_DEVICE_TREE_PARSE
 
@@ -33,6 +34,7 @@ static inline void dt_init_cpu_topology(void) {}
 
 #define cpu_to_core(_cpu)   (0)
 #define cpu_to_socket(_cpu) (0)
+#define cpu_nr_siblings(_cpu) (1)
 
 #endif /* CONFIG_DEVICE_TREE_PARSE */
 
-- 
2.43.0