[PATCH v2 08/17] 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.

Signed-off-by: Wei Chen <wei.chen@xxxxxxx>
---
v1->v2:
1. Move numa_disabled check to fdt_parse_numa_memory_node.
2. Use numa_bad to replace bad_srat.
3. Replace tabs by spaces.
4. Align parameters.
5. return ENODATA for a normal dtb without numa info.
6. Un-addressed comment:
   "Why not parse numa-node-id and call fdt_numa_memory_affinity_init
   from xen/arch/arm/bootfdt.c:device_tree_get_meminfo. Is it because
   device_tree_get_meminfo is called too early?"
   I checked the device_tree_get_meminfo code and I think the answer
   is similar as I reply in RFC. I prefer a unify numa initialization
   entry. Don't want to make numa parse code in different places.
7. Use node id as dummy PXM for numa_update_node_memblks.
---
 xen/arch/arm/numa_device_tree.c | 89 +++++++++++++++++++++++++++++++++
 1 file changed, 89 insertions(+)

diff --git a/xen/arch/arm/numa_device_tree.c b/xen/arch/arm/numa_device_tree.c
index c031053d24..793a410fd4 100644
--- a/xen/arch/arm/numa_device_tree.c
+++ b/xen/arch/arm/numa_device_tree.c
@@ -34,6 +34,26 @@ static int __init fdt_numa_processor_affinity_init(nodeid_t 
node)
     return 0;
 }
 
+/* Callback for parsing of the memory regions affinity */
+static int __init fdt_numa_memory_affinity_init(nodeid_t node,
+                                                paddr_t start, paddr_t size)
+{
+    if ( !numa_memblks_available() )
+    {
+        dprintk(XENLOG_WARNING,
+                "Too many numa entry, try bigger NR_NODE_MEMBLKS\n");
+        return -EINVAL;
+    }
+
+    numa_fw_nid_name = "numa-node-id";
+    if ( !numa_update_node_memblks(node, node, start, size, false) )
+        return -EINVAL;
+
+    device_tree_numa = DT_NUMA_ON;
+
+    return 0;
+}
+
 /* Parse CPU NUMA node info */
 static int __init fdt_parse_numa_cpu_node(const void *fdt, int node)
 {
@@ -62,3 +82,72 @@ static int __init fdt_parse_numa_cpu_node(const void *fdt, 
int node)
 
     return fdt_numa_processor_affinity_init(nid);
 }
+
+/* Parse memory node NUMA info */
+static int __init fdt_parse_numa_memory_node(const void *fdt, int node,
+                                             const char *name,
+                                             unsigned int addr_cells,
+                                             unsigned int size_cells)
+{
+    unsigned int nid;
+    int ret = 0, len;
+    paddr_t addr, size;
+    const struct fdt_property *prop;
+    unsigned int idx, ranges;
+    const __be32 *addresses;
+
+    if ( numa_disabled() )
+        return -EINVAL;
+
+    /*
+     * device_tree_get_u32 will return NUMA_NO_NODE when this memory
+     * DT node doesn't have numa-node-id. This can help us to
+     * distinguish a bad DTB and a normal DTB without NUMA info.
+     */
+    nid = device_tree_get_u32(fdt, node, "numa-node-id", NUMA_NO_NODE);
+    if ( node == NUMA_NO_NODE )
+    {
+        numa_fw_bad();
+        return -ENODATA;
+    }
+    else if ( nid >= MAX_NUMNODES )
+    {
+        printk(XENLOG_WARNING "Node id %u exceeds maximum value\n", nid);
+        goto invalid_data;
+    }
+
+    prop = fdt_get_property(fdt, node, "reg", &len);
+    if ( !prop )
+    {
+        printk(XENLOG_WARNING
+               "fdt: node `%s': missing `reg' property\n", name);
+        goto invalid_data;
+    }
+
+    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 = fdt_numa_memory_affinity_init(nid, addr, size);
+        if ( ret )
+            goto invalid_data;
+    }
+
+    if ( idx == 0 )
+    {
+        printk(XENLOG_ERR
+               "bad property in memory node, idx=%d ret=%d\n", idx, ret);
+        goto invalid_data;
+    }
+
+    return 0;
+
+invalid_data:
+    numa_fw_bad();
+    return -EINVAL;
+}
-- 
2.25.1