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>

diff --git a/arch/arm/kernel/entry-header.S b/arch/arm/kernel/entry-header.S
index ae946490016863a131f3b77b1552795d3e931c0f..051166c2a932cfed1620bb3a5612383ffff12149 100644 (file)
--- 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

diff --git a/arch/arm/mm/abort-ev6.S b/arch/arm/mm/abort-ev6.S
index f332df7f0d37be504eb1d2af35efae5edc4a579c..1478aa5221449af05fddbae38440f1858afa8299 100644 (file)
--- a/arch/arm/mm/abort-ev6.S
+++ b/arch/arm/mm/abort-ev6.S
@@ -20,11 +20,11 @@
  */
        .align  5
 ENTRY(v6_early_abort)
-#ifdef CONFIG_CPU_32v6K
-       clrex
-#else
+#ifdef CONFIG_CPU_V6
        sub     r1, sp, #4                      @ Get unused stack location
        strex   r0, r1, [r1]                    @ Clear the exclusive monitor
+#elif defined(CONFIG_CPU_32v6K)
+       clrex
 #endif
        mrc     p15, 0, r1, c5, c0, 0           @ get FSR
        mrc     p15, 0, r0, c6, c0, 0           @ get FAR