diff --git a/arch/mips/boot/dts/img/boston.dts b/arch/mips/boot/dts/img/boston.dts
index 1bd105428f61421eec2f5df8e470e7e056fb8598..65af3f6ba81c3a6515e4e9a199916c9eff131d87 100644
--- a/arch/mips/boot/dts/img/boston.dts
+++ b/arch/mips/boot/dts/img/boston.dts
@@ -51,6 +51,8 @@ pci0: pci@10000000 {
 		ranges = <0x02000000 0 0x40000000
 			  0x40000000 0 0x40000000>;
 
+		bus-range = <0x00 0xff>;
+
 		interrupt-map-mask = <0 0 0 7>;
 		interrupt-map = <0 0 0 1 &pci0_intc 1>,
 				<0 0 0 2 &pci0_intc 2>,
@@ -79,6 +81,8 @@ pci1: pci@12000000 {
 		ranges = <0x02000000 0 0x20000000
 			  0x20000000 0 0x20000000>;
 
+		bus-range = <0x00 0xff>;
+
 		interrupt-map-mask = <0 0 0 7>;
 		interrupt-map = <0 0 0 1 &pci1_intc 1>,
 				<0 0 0 2 &pci1_intc 2>,
@@ -107,6 +111,8 @@ pci2: pci@14000000 {
 		ranges = <0x02000000 0 0x16000000
 			  0x16000000 0 0x100000>;
 
+		bus-range = <0x00 0xff>;
+
 		interrupt-map-mask = <0 0 0 7>;
 		interrupt-map = <0 0 0 1 &pci2_intc 1>,
 				<0 0 0 2 &pci2_intc 2>,
diff --git a/arch/mips/include/asm/io.h b/arch/mips/include/asm/io.h
index 0cbf3af37ecad9d195847c49ddffb15a6165fc4d..a7d0b836f2f7dd9c8bf7897759aed6b9f59ade39 100644
--- a/arch/mips/include/asm/io.h
+++ b/arch/mips/include/asm/io.h
@@ -307,7 +307,7 @@ static inline void iounmap(const volatile void __iomem *addr)
 #if defined(CONFIG_CPU_CAVIUM_OCTEON) || defined(CONFIG_LOONGSON3_ENHANCEMENT)
 #define war_io_reorder_wmb()		wmb()
 #else
-#define war_io_reorder_wmb()		do { } while (0)
+#define war_io_reorder_wmb()		barrier()
 #endif
 
 #define __BUILD_MEMORY_SINGLE(pfx, bwlq, type, irq)			\
@@ -377,6 +377,8 @@ static inline type pfx##read##bwlq(const volatile void __iomem *mem)	\
 		BUG();							\
 	}								\
 									\
+	/* prevent prefetching of coherent DMA data prematurely */	\
+	rmb();								\
 	return pfx##ioswab##bwlq(__mem, __val);				\
 }
 
diff --git a/arch/mips/include/asm/uaccess.h b/arch/mips/include/asm/uaccess.h
index b713069472903c26f21c11424113765a5156d955..06629011a4342f490bf4bcabd9e4fe06ed0952ac 100644
--- a/arch/mips/include/asm/uaccess.h
+++ b/arch/mips/include/asm/uaccess.h
@@ -654,6 +654,13 @@ __clear_user(void __user *addr, __kernel_size_t size)
 {
 	__kernel_size_t res;
 
+#ifdef CONFIG_CPU_MICROMIPS
+/* micromips memset / bzero also clobbers t7 & t8 */
+#define bzero_clobbers "$4", "$5", "$6", __UA_t0, __UA_t1, "$15", "$24", "$31"
+#else
+#define bzero_clobbers "$4", "$5", "$6", __UA_t0, __UA_t1, "$31"
+#endif /* CONFIG_CPU_MICROMIPS */
+
 	if (eva_kernel_access()) {
 		__asm__ __volatile__(
 			"move\t$4, %1\n\t"
@@ -663,7 +670,7 @@ __clear_user(void __user *addr, __kernel_size_t size)
 			"move\t%0, $6"
 			: "=r" (res)
 			: "r" (addr), "r" (size)
-			: "$4", "$5", "$6", __UA_t0, __UA_t1, "$31");
+			: bzero_clobbers);
 	} else {
 		might_fault();
 		__asm__ __volatile__(
@@ -674,7 +681,7 @@ __clear_user(void __user *addr, __kernel_size_t size)
 			"move\t%0, $6"
 			: "=r" (res)
 			: "r" (addr), "r" (size)
-			: "$4", "$5", "$6", __UA_t0, __UA_t1, "$31");
+			: bzero_clobbers);
 	}
 
 	return res;
diff --git a/arch/mips/lib/memset.S b/arch/mips/lib/memset.S
index a1456664d6c28c9ccc8f837e341fe1a760b3c2d6..f7327979a8f8e163547dafe4302d12caab809fbd 100644
--- a/arch/mips/lib/memset.S
+++ b/arch/mips/lib/memset.S
@@ -219,7 +219,7 @@
 1:	PTR_ADDIU	a0, 1			/* fill bytewise */
 	R10KCBARRIER(0(ra))
 	bne		t1, a0, 1b
-	sb		a1, -1(a0)
+	 EX(sb, a1, -1(a0), .Lsmall_fixup\@)
 
 2:	jr		ra			/* done */
 	move		a2, zero
@@ -252,13 +252,18 @@
 	PTR_L		t0, TI_TASK($28)
 	andi		a2, STORMASK
 	LONG_L		t0, THREAD_BUADDR(t0)
-	LONG_ADDU	a2, t1
+	LONG_ADDU	a2, a0
 	jr		ra
 	LONG_SUBU	a2, t0
 
 .Llast_fixup\@:
 	jr		ra
-	andi		v1, a2, STORMASK
+	 nop
+
+.Lsmall_fixup\@:
+	PTR_SUBU	a2, t1, a0
+	jr		ra
+	 PTR_ADDIU	a2, 1
 
 	.endm