On 8/6/21 12:17 PM, David Gibson wrote:

On Tue, Jul 27, 2021 at 03:33:11PM +0530, Aneesh Kumar K.V wrote:

quoted

Currently, we duplicate parsing code for ibm,associativity and
ibm,associativity-lookup-arrays in the kernel. The associativity array provided
by these device tree properties are very similar and hence can use
a helper to parse the node id and numa distance details.

Oh... sorry.. comments on the earlier patch were from before I read
and saw you adjusted things here.

quoted

Signed-off-by: Aneesh Kumar K.V <redacted>
---
  arch/powerpc/mm/numa.c | 83 ++++++++++++++++++++++++++----------------
  1 file changed, 51 insertions(+), 32 deletions(-)

diff --git a/arch/powerpc/mm/numa.c b/arch/powerpc/mm/numa.c
index fffb3c40f595..7506251e17f2 100644
--- a/arch/powerpc/mm/numa.c
+++ b/arch/powerpc/mm/numa.c

@@ -171,19 +171,19 @@ static void unmap_cpu_from_node(unsigned long cpu)
  }
  #endif /* CONFIG_HOTPLUG_CPU || CONFIG_PPC_SPLPAR */
  
-/*
- * Returns nid in the range [0..nr_node_ids], or -1 if no useful NUMA
- * info is found.
- */
-static int associativity_to_nid(const __be32 *associativity)
+static int __associativity_to_nid(const __be32 *associativity,
+				  int max_array_sz)
  {
  	int nid = NUMA_NO_NODE;
+	/*
+	 * primary_domain_index is 1 based array index.
+	 */
+	int index = primary_domain_index  - 1;
  
-	if (!numa_enabled)
+	if (!numa_enabled || index >= max_array_sz)
  		goto out;

You don't need a goto, you can just return NUMA_NO_NODE.

updated

quoted

  
-	if (of_read_number(associativity, 1) >= primary_domain_index)
-		nid = of_read_number(&associativity[primary_domain_index], 1);
+	nid = of_read_number(&associativity[index], 1);
  
  	/* POWER4 LPAR uses 0xffff as invalid node */
  	if (nid == 0xffff || nid >= nr_node_ids)

@@ -191,6 +191,17 @@ static int associativity_to_nid(const __be32 *associativity)
  out:
  	return nid;
  }
+/*
+ * Returns nid in the range [0..nr_node_ids], or -1 if no useful NUMA
+ * info is found.
+ */
+static int associativity_to_nid(const __be32 *associativity)
+{
+	int array_sz = of_read_number(associativity, 1);
+
+	/* Skip the first element in the associativity array */
+	return __associativity_to_nid((associativity + 1), array_sz);
+}
  
  static int __cpu_form2_relative_distance(__be32 *cpu1_assoc, __be32 *cpu2_assoc)
  {

@@ -295,24 +306,41 @@ int of_node_to_nid(struct device_node *device)
  }
  EXPORT_SYMBOL(of_node_to_nid);
  
-static void __initialize_form1_numa_distance(const __be32 *associativity)
+static void ___initialize_form1_numa_distance(const __be32 *associativity,
+					     int max_array_sz)
  {
  	int i, nid;
  
  	if (affinity_form != FORM1_AFFINITY)
  		return;
  
-	nid = associativity_to_nid(associativity);
+	nid = __associativity_to_nid(associativity, max_array_sz);
  	if (nid != NUMA_NO_NODE) {
  		for (i = 0; i < distance_ref_points_depth; i++) {
  			const __be32 *entry;
+			int index = be32_to_cpu(distance_ref_points[i]) - 1;
+
+			/*
+			 * broken hierarchy, return with broken distance table

WARN_ON, maybe?

updated

quoted

+			 */
+			if (index >= max_array_sz)
+				return;
  
-			entry = &associativity[be32_to_cpu(distance_ref_points[i])];
+			entry = &associativity[index];
  			distance_lookup_table[nid][i] = of_read_number(entry, 1);
  		}
  	}
  }
  
+static void __initialize_form1_numa_distance(const __be32 *associativity)

Do you actually use this in-between wrapper?

yes used in

static void initialize_form1_numa_distance(struct device_node *node)
{
	const __be32 *associativity;

	associativity = of_get_associativity(node);
	if (!associativity)
		return;

	__initialize_form1_numa_distance(associativity);
}

quoted

+{
+	int array_sz;
+
+	array_sz = of_read_number(associativity, 1);
+	/* Skip the first element in the associativity array */
+	___initialize_form1_numa_distance(associativity + 1, array_sz);
+}
+
  static void initialize_form1_numa_distance(struct device_node *node)
  {
  	const __be32 *associativity;

@@ -586,27 +614,18 @@ static int get_nid_and_numa_distance(struct drmem_lmb *lmb)
  
  	if (primary_domain_index <= aa.array_sz &&
  	    !(lmb->flags & DRCONF_MEM_AI_INVALID) && lmb->aa_index < aa.n_arrays) {
-		index = lmb->aa_index * aa.array_sz + primary_domain_index - 1;
-		nid = of_read_number(&aa.arrays[index], 1);
+		const __be32 *associativity;
  
-		if (nid == 0xffff || nid >= nr_node_ids)
-			nid = default_nid;
+		index = lmb->aa_index * aa.array_sz;
+		associativity = &aa.arrays[index];
+		nid = __associativity_to_nid(associativity, aa.array_sz);
  		if (nid > 0 && affinity_form == FORM1_AFFINITY) {
-			int i;
-			const __be32 *associativity;
-
-			index = lmb->aa_index * aa.array_sz;
-			associativity = &aa.arrays[index];
  			/*
-			 * lookup array associativity entries have different format
-			 * There is no length of the array as the first element.
+			 * lookup array associativity entries have
+			 * no length of the array as the first element.
  			 */
-			for (i = 0; i < distance_ref_points_depth; i++) {
-				const __be32 *entry;
-
-				entry = &associativity[be32_to_cpu(distance_ref_points[i]) - 1];
-				distance_lookup_table[nid][i] = of_read_number(entry, 1);
-			}
+			___initialize_form1_numa_distance(associativity,
+							  aa.array_sz);

Better, thanks.

quoted

  		}
  	}
  	return nid;

@@ -632,11 +651,11 @@ int of_drconf_to_nid_single(struct drmem_lmb *lmb)
  
  	if (primary_domain_index <= aa.array_sz &&
  	    !(lmb->flags & DRCONF_MEM_AI_INVALID) && lmb->aa_index < aa.n_arrays) {
-		index = lmb->aa_index * aa.array_sz + primary_domain_index - 1;
-		nid = of_read_number(&aa.arrays[index], 1);
+		const __be32 *associativity;
  
-		if (nid == 0xffff || nid >= nr_node_ids)
-			nid = default_nid;
+		index = lmb->aa_index * aa.array_sz;
+		associativity = &aa.arrays[index];
+		nid = __associativity_to_nid(associativity, aa.array_sz);
  	}
  	return nid;
  }

-aneesh