diff --git a/arch/powerpc/kernel/prom_init.c b/arch/powerpc/kernel/prom_init.c
index 53503937de0e..055cb5f2d37f 100644
--- a/arch/powerpc/kernel/prom_init.c
+++ b/arch/powerpc/kernel/prom_init.c
@@ -86,6 +86,12 @@
  */
 #define ADDR(x)		(u32)(unsigned long)(x)
 
+/*
+ * Current Power system firmware caps the PVR list array size at 16 entries
+ * during CAS (Client Architecture Support) negotiation.
+ */
+#define CAS_MAX_PVR_ENTRIES	16
+
 #ifdef CONFIG_PPC64
 #define OF_WORKAROUNDS	0
 #else
@@ -979,6 +985,10 @@ static const struct ibm_arch_vec ibm_architecture_vec_template __initconst = {
 			.mask = cpu_to_be32(0xfffe0000), /* POWER5/POWER5+ */
 			.val  = cpu_to_be32(0x003a0000),
 		},
+		{
+			.mask = cpu_to_be32(0xffffffff), /* all 2.04-compliant and earlier */
+			.val  = cpu_to_be32(0x0f000001),
+		},
 		{
 			.mask = cpu_to_be32(0xffff0000), /* POWER6 */
 			.val  = cpu_to_be32(0x003e0000),
@@ -1032,13 +1042,9 @@ static const struct ibm_arch_vec ibm_architecture_vec_template __initconst = {
 			.val  = cpu_to_be32(0x0f000003),
 		},
 		{
-			.mask = cpu_to_be32(0xffffffff), /* all 2.05-compliant */
+			.mask = cpu_to_be32(0xfffffffd), /* all 2.05-compliant */
 			.val  = cpu_to_be32(0x0f000002),
 		},
-		{
-			.mask = cpu_to_be32(0xfffffffe), /* all 2.04-compliant and earlier */
-			.val  = cpu_to_be32(0x0f000001),
-		},
 	},
 
 	.num_vectors = NUM_VECTORS(6),
@@ -1403,6 +1409,22 @@ static void __init prom_send_capabilities(void)
 	ihandle root;
 	prom_arg_t ret;
 	u32 cores;
+	int start_index = 0;
+
+	/*
+	 * Ensure that when running on Power11 or below hardware, the number
+	 * of PVR entries passed during CAS negotiation does not exceed the
+	 * firmware-imposed limit of 16.
+	 *
+	 * Compute the start_index to skip the oldest leading pvrs[] entries
+	 * when running on Power11 or below hardware, so that the pointer
+	 * passed to ibm,client-architecture-support points to
+	 * ibm_architecture_vec.pvrs[start_index], presenting exactly 16
+	 * entries to firmware.
+	 */
+	if ((ARRAY_SIZE(ibm_architecture_vec_template.pvrs) > CAS_MAX_PVR_ENTRIES) &&
+	    (PVR_VER(mfspr(SPRN_PVR)) <= PVR_POWER11))
+		start_index = ARRAY_SIZE(ibm_architecture_vec_template.pvrs) - CAS_MAX_PVR_ENTRIES;
 
 	/* Check ibm,arch-vec-5-platform-support and fixup vec5 if required */
 	prom_check_platform_support();
@@ -1427,7 +1449,7 @@ static void __init prom_send_capabilities(void)
 		if (call_prom_ret("call-method", 3, 2, &ret,
 				  ADDR("ibm,client-architecture-support"),
 				  root,
-				  ADDR(&ibm_architecture_vec)) == 0) {
+				  ADDR(&ibm_architecture_vec.pvrs[start_index])) == 0) {
 			/* the call exists... */
 			if (ret)
 				prom_printf("\nWARNING: ibm,client-architecture"