diff --git a/Documentation/kernel-parameters.txt b/Documentation/kernel-parameters.txt
index 82b42c958d1c..738bae4a5958 100644
--- a/Documentation/kernel-parameters.txt
+++ b/Documentation/kernel-parameters.txt
@@ -920,6 +920,12 @@ bytes respectively. Such letter suffixes can also be entirely omitted.
 	dhash_entries=	[KNL]
 			Set number of hash buckets for dentry cache.
 
+	disable_1tb_segments [PPC]
+			Disables the use of 1TB hash page table segments. This
+			causes the kernel to fall back to 256MB segments which
+			can be useful when debugging issues that require an SLB
+			miss to occur.
+
 	disable=	[IPV6]
 			See Documentation/networking/ipv6.txt.
 
diff --git a/arch/powerpc/mm/hash_utils_64.c b/arch/powerpc/mm/hash_utils_64.c
index b2740c67e172..fab46dbe68b3 100644
--- a/arch/powerpc/mm/hash_utils_64.c
+++ b/arch/powerpc/mm/hash_utils_64.c
@@ -317,6 +317,15 @@ int htab_remove_mapping(unsigned long vstart, unsigned long vend,
 	return ret;
 }
 
+static bool disable_1tb_segments = false;
+
+static int __init parse_disable_1tb_segments(char *p)
+{
+	disable_1tb_segments = true;
+	return 0;
+}
+early_param("disable_1tb_segments", parse_disable_1tb_segments);
+
 static int __init htab_dt_scan_seg_sizes(unsigned long node,
 					 const char *uname, int depth,
 					 void *data)
@@ -335,6 +344,12 @@ static int __init htab_dt_scan_seg_sizes(unsigned long node,
 	for (; size >= 4; size -= 4, ++prop) {
 		if (be32_to_cpu(prop[0]) == 40) {
 			DBG("1T segment support detected\n");
+
+			if (disable_1tb_segments) {
+				DBG("1T segments disabled by command line\n");
+				break;
+			}
+
 			cur_cpu_spec->mmu_features |= MMU_FTR_1T_SEGMENT;
 			return 1;
 		}