diff --git a/arch/mips/lib/memset.S b/arch/mips/lib/memset.S
index fac26ce64b2f..3a6f34ef5ffc 100644
--- a/arch/mips/lib/memset.S
+++ b/arch/mips/lib/memset.S
@@ -232,16 +232,25 @@
 
 #ifdef CONFIG_CPU_MIPSR6
 .Lbyte_fixup\@:
+	/*
+	 * unset_bytes = (#bytes - (#unaligned bytes)) - (-#unaligned bytes remaining + 1) + 1
+	 *      a2     =             a2                -              t0                   + 1
+	 */
 	PTR_SUBU	a2, t0
 	jr		ra
 	 PTR_ADDIU	a2, 1
 #endif /* CONFIG_CPU_MIPSR6 */
 
 .Lfirst_fixup\@:
+	/* unset_bytes already in a2 */
 	jr	ra
 	 nop
 
 .Lfwd_fixup\@:
+	/*
+	 * unset_bytes = partial_start_addr +  #bytes   -     fault_addr
+	 *      a2     =         t1         + (a2 & 3f) - $28->task->BUADDR
+	 */
 	PTR_L		t0, TI_TASK($28)
 	andi		a2, 0x3f
 	LONG_L		t0, THREAD_BUADDR(t0)
@@ -250,6 +259,10 @@
 	 LONG_SUBU	a2, t0
 
 .Lpartial_fixup\@:
+	/*
+	 * unset_bytes = partial_end_addr +      #bytes     -     fault_addr
+	 *      a2     =       a0         + (a2 & STORMASK) - $28->task->BUADDR
+	 */
 	PTR_L		t0, TI_TASK($28)
 	andi		a2, STORMASK
 	LONG_L		t0, THREAD_BUADDR(t0)
@@ -258,10 +271,15 @@
 	 LONG_SUBU	a2, t0
 
 .Llast_fixup\@:
+	/* unset_bytes already in a2 */
 	jr		ra
 	 nop
 
 .Lsmall_fixup\@:
+	/*
+	 * unset_bytes = end_addr - current_addr + 1
+	 *      a2     =    t1    -      a0      + 1
+	 */
 	PTR_SUBU	a2, t1, a0
 	jr		ra
 	 PTR_ADDIU	a2, 1