ARM: v6k: select clear exclusive code seqences according to V6 variants

If CONFIG_CPU_V6 is enabled, then the kernel must support ARMv6 CPUs
which don't have the V6K extensions implemented.  Always use the
dummy store-exclusive method to ensure that the exclusive monitors are
cleared.

If CONFIG_CPU_V6 is not set, but CONFIG_CPU_32v6K is enabled, then we
have the K extensions available on all CPUs we're building support for,
so we can use the new clear-exclusive instruction.

Acked-by: Tony Lindgren <tony@atomide.com>
Tested-by: Sourav Poddar <sourav.poddar@ti.com>
Tested-by: Will Deacon <will.deacon@arm.com>
Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>

1 files changed, 7 insertions, 7 deletions

diff --git a/arch/arm/kernel/entry-header.S b/arch/arm/kernel/entry-header.S
index ae9464900168..051166c2a932 100644
--- a/arch/arm/kernel/entry-header.S
+++ b/arch/arm/kernel/entry-header.S
@@ -76,13 +76,13 @@
 #ifndef CONFIG_THUMB2_KERNEL
         .macro  svc_exit, rpsr
         msr     spsr_cxsf, \rpsr
-#if defined(CONFIG_CPU_32v6K)
-        clrex                                   @ clear the exclusive monitor
-        ldmia   sp, {r0 - pc}^                  @ load r0 - pc, cpsr
-#elif defined (CONFIG_CPU_V6)
+#if defined(CONFIG_CPU_V6)
         ldr     r0, [sp]
         strex   r1, r2, [sp]                    @ clear the exclusive monitor
         ldmib   sp, {r1 - pc}^                  @ load r1 - pc, cpsr
+#elif defined(CONFIG_CPU_32v6K)
+        clrex                                   @ clear the exclusive monitor
+        ldmia   sp, {r0 - pc}^                  @ load r0 - pc, cpsr
 #else
         ldmia   sp, {r0 - pc}^                  @ load r0 - pc, cpsr
 #endif
@@ -92,10 +92,10 @@
         ldr     r1, [sp, #\offset + S_PSR]      @ get calling cpsr
         ldr     lr, [sp, #\offset + S_PC]!      @ get pc
         msr     spsr_cxsf, r1                   @ save in spsr_svc
-#if defined(CONFIG_CPU_32v6K)
-        clrex                                   @ clear the exclusive monitor
-#elif defined (CONFIG_CPU_V6)
+#if defined(CONFIG_CPU_V6)
         strex   r1, r2, [sp]                    @ clear the exclusive monitor
+#elif defined(CONFIG_CPU_32v6K)
+        clrex                                   @ clear the exclusive monitor
 #endif
         .if     \fast
         ldmdb   sp, {r1 - lr}^                  @ get calling r1 - lr