[XEN RFC PATCH 23/40] xen/arm: introduce a helper to parse device tree memory node

[Wei Chen <wei.chen@xxxxxxx>]

Memory blocks' NUMA ID information is stored in device tree's
memory nodes as "numa-node-id". We need a new helper to parse
and verify this ID from memory nodes.

In order to support memory affinity in later use, the valid
memory ranges and NUMA ID will be saved to tables.

Signed-off-by: Wei Chen <wei.chen@xxxxxxx>
---
 xen/arch/arm/numa_device_tree.c | 130 ++++++++++++++++++++++++++++++++
 1 file changed, 130 insertions(+)

diff --git a/xen/arch/arm/numa_device_tree.c b/xen/arch/arm/numa_device_tree.c
index 37cc56acf3..bbe081dcd1 100644
--- a/xen/arch/arm/numa_device_tree.c
+++ b/xen/arch/arm/numa_device_tree.c
@@ -20,11 +20,13 @@
 #include <xen/init.h>
 #include <xen/nodemask.h>
 #include <xen/numa.h>
+#include <xen/libfdt/libfdt.h>
 #include <xen/device_tree.h>
 #include <asm/setup.h>
 
 s8 device_tree_numa = 0;
 static nodemask_t processor_nodes_parsed __initdata;
+static nodemask_t memory_nodes_parsed __initdata;
 
 static int srat_disabled(void)
 {
@@ -55,6 +57,79 @@ static int __init dtb_numa_processor_affinity_init(nodeid_t 
node)
     return 0;
 }
 
+/* Callback for parsing of the memory regions affinity */
+static int __init dtb_numa_memory_affinity_init(nodeid_t node,
+                                paddr_t start, paddr_t size)
+{
+    struct node *nd;
+    paddr_t end;
+    int i;
+
+    if ( srat_disabled() )
+        return -EINVAL;
+
+    end = start + size;
+    if ( num_node_memblks >= NR_NODE_MEMBLKS )
+    {
+        dprintk(XENLOG_WARNING,
+                "Too many numa entry, try bigger NR_NODE_MEMBLKS \n");
+        bad_srat();
+        return -EINVAL;
+    }
+
+    /* It is fine to add this area to the nodes data it will be used later */
+    i = conflicting_memblks(start, end);
+    /* No conflicting memory block, we can save it for later usage */;
+    if ( i < 0 )
+        goto save_memblk;
+
+    if ( memblk_nodeid[i] == node ) {
+        /*
+         * Overlaps with other memblk in the same node, warning here.
+         * This memblk will be merged with conflicted memblk later.
+         */
+        printk(XENLOG_WARNING
+               "DT: NUMA NODE %u (%"PRIx64
+               "-%"PRIx64") overlaps with itself (%"PRIx64"-%"PRIx64")\n",
+               node, start, end,
+               node_memblk_range[i].start, node_memblk_range[i].end);
+    } else {
+        /*
+         * Conflict with memblk in other node, this is an error.
+         * The NUMA information is invalid, NUMA will be turn off.
+         */
+        printk(XENLOG_ERR
+               "DT: NUMA NODE %u (%"PRIx64"-%"
+               PRIx64") overlaps with NODE %u (%"PRIx64"-%"PRIx64")\n",
+               node, start, end, memblk_nodeid[i],
+               node_memblk_range[i].start, node_memblk_range[i].end);
+        bad_srat();
+        return -EINVAL;
+    }
+
+save_memblk:
+    nd = &nodes[node];
+    if ( !node_test_and_set(node, memory_nodes_parsed) ) {
+        nd->start = start;
+        nd->end = end;
+    } else {
+        if ( start < nd->start )
+            nd->start = start;
+        if ( nd->end < end )
+            nd->end = end;
+    }
+
+    printk(XENLOG_INFO "DT: NUMA node %u %"PRIx64"-%"PRIx64"\n",
+           node, start, end);
+
+    node_memblk_range[num_node_memblks].start = start;
+    node_memblk_range[num_node_memblks].end = end;
+    memblk_nodeid[num_node_memblks] = node;
+    num_node_memblks++;
+
+    return 0;
+}
+
 /* Parse CPU NUMA node info */
 int __init device_tree_parse_numa_cpu_node(const void *fdt, int node)
 {
@@ -70,3 +145,58 @@ int __init device_tree_parse_numa_cpu_node(const void *fdt, 
int node)
 
     return dtb_numa_processor_affinity_init(nid);
 }
+
+/* Parse memory node NUMA info */
+int __init
+device_tree_parse_numa_memory_node(const void *fdt, int node,
+    const char *name, uint32_t addr_cells, uint32_t size_cells)
+{
+    uint32_t nid;
+    int ret = 0, len;
+    paddr_t addr, size;
+    const struct fdt_property *prop;
+    uint32_t idx, ranges;
+    const __be32 *addresses;
+
+    nid = device_tree_get_u32(fdt, node, "numa-node-id", MAX_NUMNODES);
+    if ( nid >= MAX_NUMNODES )
+    {
+        printk(XENLOG_WARNING "Node id %u exceeds maximum value\n", nid);
+        return -EINVAL;
+    }
+
+    prop = fdt_get_property(fdt, node, "reg", &len);
+    if ( !prop )
+    {
+        printk(XENLOG_WARNING
+               "fdt: node `%s': missing `reg' property\n", name);
+        return -EINVAL;
+    }
+
+    addresses = (const __be32 *)prop->data;
+    ranges = len / (sizeof(__be32)* (addr_cells + size_cells));
+    for ( idx = 0; idx < ranges; idx++ )
+    {
+        device_tree_get_reg(&addresses, addr_cells, size_cells, &addr, &size);
+        /* Skip zero size ranges */
+        if ( !size )
+            continue;
+
+        ret = dtb_numa_memory_affinity_init(nid, addr, size);
+        if ( ret ) {
+            printk(XENLOG_WARNING
+                   "NUMA: process range#%d addr = %lx size=%lx failed!\n",
+                   idx, addr, size);
+            return -EINVAL;
+        }
+    }
+
+    if ( idx == 0 )
+    {
+        printk(XENLOG_ERR
+               "bad property in memory node, idx=%d ret=%d\n", idx, ret);
+        return -EINVAL;
+    }
+
+    return 0;
+}
-- 
2.25.1