4 files changed, 63 insertions, 10 deletions

diff --git a/arch/arm/include/asm/assembler.h b/arch/arm/include/asm/assembler.h
index 6e8f05c8a1c8..062b58c029ab 100644
--- a/arch/arm/include/asm/assembler.h
+++ b/arch/arm/include/asm/assembler.h
@@ -154,16 +154,39 @@
         .long   9999b,9001f;                    \
         .popsection
 
+#ifdef CONFIG_SMP
+#define ALT_SMP(instr...)                                       \
+9998:   instr
+#define ALT_UP(instr...)                                        \
+        .pushsection ".alt.smp.init", "a"                       ;\
+        .long   9998b                                           ;\
+        instr                                                   ;\
+        .popsection
+#define ALT_UP_B(label)                                 \
+        .equ    up_b_offset, label - 9998b                      ;\
+        .pushsection ".alt.smp.init", "a"                       ;\
+        .long   9998b                                           ;\
+        b       . + up_b_offset                                 ;\
+        .popsection
+#else
+#define ALT_SMP(instr...)
+#define ALT_UP(instr...) instr
+#define ALT_UP_B(label) b label
+#endif
+
 /*
  * SMP data memory barrier
  */
         .macro  smp_dmb
 #ifdef CONFIG_SMP
 #if __LINUX_ARM_ARCH__ >= 7
-        dmb
+        ALT_SMP(dmb)
 #elif __LINUX_ARM_ARCH__ == 6
-        mcr     p15, 0, r0, c7, c10, 5  @ dmb
+        ALT_SMP(mcr     p15, 0, r0, c7, c10, 5) @ dmb
+#else
+#error Incompatible SMP platform
 #endif
+        ALT_UP(nop)
 #endif
         .endm
 
diff --git a/arch/arm/include/asm/smp_mpidr.h b/arch/arm/include/asm/smp_mpidr.h
index 7da7105e83e5..6a9307d64900 100644
--- a/arch/arm/include/asm/smp_mpidr.h
+++ b/arch/arm/include/asm/smp_mpidr.h
@@ -4,7 +4,12 @@
 #define hard_smp_processor_id()                                         \
         ({                                                              \
                 unsigned int cpunum;                                    \
-                __asm__("mrc p15, 0, %0, c0, c0, 5\n"                   \
+                __asm__("\n"                                            \
+                        "1:     mrc p15, 0, %0, c0, c0, 5\n"            \
+                        "       .pushsection \".alt.smp.init\", \"a\"\n"\
+                        "       .long   1b\n"                           \
+                        "       mov     %0, #0\n"                       \
+                        "       .popsection"                            \
                         : "=r" (cpunum));                               \
                 cpunum &= 0x0F;                                         \
         })
diff --git a/arch/arm/include/asm/smp_plat.h b/arch/arm/include/asm/smp_plat.h
index e6215305544a..7de5aa56c18b 100644
--- a/arch/arm/include/asm/smp_plat.h
+++ b/arch/arm/include/asm/smp_plat.h
@@ -18,4 +18,19 @@ static inline int cache_ops_need_broadcast(void)
         return ((read_cpuid_ext(CPUID_EXT_MMFR3) >> 12) & 0xf) < 1;
 }
 
+/*
+ * Return true if we are running on a SMP platform
+ */
+static inline bool is_smp(void)
+{
+#ifndef CONFIG_SMP
+        return false;
+#elif defined(CONFIG_SMP_ON_UP)
+        extern unsigned int smp_on_up;
+        return !!smp_on_up;
+#else
+        return true;
+#endif
+}
+
 #endif
diff --git a/arch/arm/include/asm/tlbflush.h b/arch/arm/include/asm/tlbflush.h
index 33b546ae72d4..cf2f018492e0 100644
--- a/arch/arm/include/asm/tlbflush.h
+++ b/arch/arm/include/asm/tlbflush.h
@@ -70,6 +70,10 @@
 #undef _TLB
 #undef MULTI_TLB
 
+#ifdef CONFIG_SMP_ON_UP
+#define MULTI_TLB 1
+#endif
+
 #define v3_tlb_flags    (TLB_V3_FULL | TLB_V3_PAGE)
 
 #ifdef CONFIG_CPU_TLB_V3
@@ -185,17 +189,23 @@
 # define v6wbi_always_flags     (-1UL)
 #endif
 
-#ifdef CONFIG_SMP
-#define v7wbi_tlb_flags (TLB_WB | TLB_DCLEAN | TLB_V7_IS_BTB | \
+#define v7wbi_tlb_flags_smp     (TLB_WB | TLB_DCLEAN | TLB_V7_IS_BTB | \
                          TLB_V7_UIS_FULL | TLB_V7_UIS_PAGE | TLB_V7_UIS_ASID)
-#else
-#define v7wbi_tlb_flags (TLB_WB | TLB_DCLEAN | TLB_BTB | \
+#define v7wbi_tlb_flags_up      (TLB_WB | TLB_DCLEAN | TLB_BTB | \
                          TLB_V6_U_FULL | TLB_V6_U_PAGE | TLB_V6_U_ASID)
-#endif
 
 #ifdef CONFIG_CPU_TLB_V7
-# define v7wbi_possible_flags   v7wbi_tlb_flags
-# define v7wbi_always_flags     v7wbi_tlb_flags
+
+# ifdef CONFIG_SMP_ON_UP
+#  define v7wbi_possible_flags  (v7wbi_tlb_flags_smp | v7wbi_tlb_flags_up)
+#  define v7wbi_always_flags    (v7wbi_tlb_flags_smp & v7wbi_tlb_flags_up)
+# elif defined(CONFIG_SMP)
+#  define v7wbi_possible_flags  v7wbi_tlb_flags_smp
+#  define v7wbi_always_flags    v7wbi_tlb_flags_smp
+# else
+#  define v7wbi_possible_flags  v7wbi_tlb_flags_up
+#  define v7wbi_always_flags    v7wbi_tlb_flags_up
+# endif
 # ifdef _TLB
 #  define MULTI_TLB 1
 # else