[PATCH 26/37] xen/arm: build NUMA cpu_to_node map in dt_smp_init_cpus

[Wei Chen]

NUMA implementation has a cpu_to_node array to store CPU to NODE
map. Xen is using CPU logical ID in runtime components, so we
use CPU logical ID as CPU index in cpu_to_node.

In device tree case, cpu_logical_map is created in dt_smp_init_cpus.
So, when NUMA is enabled, dt_smp_init_cpus will fetch CPU NUMA id
at the same time for cpu_to_node.

Signed-off-by: Wei Chen <wei.c...@arm.com>
---
 xen/arch/arm/smpboot.c     | 37 ++++++++++++++++++++++++++++++++++++-
 xen/include/asm-arm/numa.h |  5 +++++
 2 files changed, 41 insertions(+), 1 deletion(-)

diff --git a/xen/arch/arm/smpboot.c b/xen/arch/arm/smpboot.c
index 60c0e82fc5..6e3cc8d3cc 100644
--- a/xen/arch/arm/smpboot.c
+++ b/xen/arch/arm/smpboot.c
@@ -121,7 +121,12 @@ static void __init dt_smp_init_cpus(void)
     {
         [0 ... NR_CPUS - 1] = MPIDR_INVALID
     };
+    static nodeid_t node_map[NR_CPUS] __initdata =
+    {
+        [0 ... NR_CPUS - 1] = NUMA_NO_NODE
+    };
     bool bootcpu_valid = false;
+    uint32_t nid = 0;
     int rc;
 
     mpidr = system_cpuinfo.mpidr.bits & MPIDR_HWID_MASK;
@@ -172,6 +177,28 @@ static void __init dt_smp_init_cpus(void)
             continue;
         }
 
+        if ( IS_ENABLED(CONFIG_NUMA) )
+        {
+            /*
+             * When CONFIG_NUMA is set, try to fetch numa infomation
+             * from CPU dts node, otherwise the nid is always 0.
+             */
+            if ( !dt_property_read_u32(cpu, "numa-node-id", &nid) )
+            {
+                printk(XENLOG_WARNING
+                       "cpu[%d] dts path: %s: doesn't have numa 
information!\n",
+                       cpuidx, dt_node_full_name(cpu));
+                /*
+                 * During the early stage of NUMA initialization, when Xen
+                 * found any CPU dts node doesn't have numa-node-id info, the
+                 * NUMA will be treated as off, all CPU will be set to a FAKE
+                 * node 0. So if we get numa-node-id failed here, we should
+                 * set nid to 0.
+                 */
+                nid = 0;
+            }
+        }
+
         /*
          * 8 MSBs must be set to 0 in the DT since the reg property
          * defines the MPIDR[23:0]
@@ -231,9 +258,12 @@ static void __init dt_smp_init_cpus(void)
         {
             printk("cpu%d init failed (hwid %"PRIregister"): %d\n", i, hwid, 
rc);
             tmp_map[i] = MPIDR_INVALID;
+            node_map[i] = NUMA_NO_NODE;
         }
-        else
+        else {
             tmp_map[i] = hwid;
+            node_map[i] = nid;
+        }
     }
 
     if ( !bootcpu_valid )
@@ -249,6 +279,11 @@ static void __init dt_smp_init_cpus(void)
             continue;
         cpumask_set_cpu(i, &cpu_possible_map);
         cpu_logical_map(i) = tmp_map[i];
+
+        nid = node_map[i];
+        if ( nid >= MAX_NUMNODES )
+            nid = 0;
+        numa_set_node(i, nid);
     }
 }
 
diff --git a/xen/include/asm-arm/numa.h b/xen/include/asm-arm/numa.h
index 758eafeb05..8a4ad379e0 100644
--- a/xen/include/asm-arm/numa.h
+++ b/xen/include/asm-arm/numa.h
@@ -46,6 +46,11 @@ extern mfn_t first_valid_mfn;
 #define node_start_pfn(nid) (mfn_x(first_valid_mfn))
 #define __node_distance(a, b) (20)
 
+static inline void numa_set_node(int cpu, nodeid_t node)
+{
+
+}
+
 #endif
 
 static inline unsigned int arch_have_default_dmazone(void)
-- 
2.25.1