Merge branch 'from-linus'

[sfrench/cifs-2.6.git] / arch / arm / kernel / entry-armv.S

diff --git a/arch/arm/kernel/entry-armv.S b/arch/arm/kernel/entry-armv.S
index 874e6bb7940578fd86878e69ae9ddc7b91eee03f..ec48d70c6d8b92d83db16b0f3ce9360944021c54 100644 (file)
--- a/arch/arm/kernel/entry-armv.S
+++ b/arch/arm/kernel/entry-armv.S
@@ -333,9 +333,13 @@ __pabt_svc:
                                        @ from the exception stack
 
 #if __LINUX_ARM_ARCH__ < 6 && !defined(CONFIG_NEEDS_SYSCALL_FOR_CMPXCHG)
+#ifndef CONFIG_MMU
+#warning "NPTL on non MMU needs fixing"
+#else
        @ make sure our user space atomic helper is aborted
        cmp     r2, #TASK_SIZE
        bichs   r3, r3, #PSR_Z_BIT
+#endif
 #endif
 
        @
@@ -562,7 +566,7 @@ ENTRY(__switch_to)
        ldr     r6, [r2, #TI_CPU_DOMAIN]!
 #endif
 #if __LINUX_ARM_ARCH__ >= 6
-#ifdef CONFIG_CPU_MPCORE
+#ifdef CONFIG_CPU_32v6K
        clrex
 #else
        strex   r5, r4, [ip]                    @ Clear exclusive monitor
@@ -705,7 +709,12 @@ __kuser_memory_barrier:                            @ 0xffff0fa0
  * The C flag is also set if *ptr was changed to allow for assembly
  * optimization in the calling code.
  *
- * Note: this routine already includes memory barriers as needed.
+ * Notes:
+ *
+ *    - This routine already includes memory barriers as needed.
+ *
+ *    - A failure might be transient, i.e. it is possible, although unlikely,
+ *      that "failure" be returned even if *ptr == oldval.
  *
  * For example, a user space atomic_add implementation could look like this:
  *
@@ -735,8 +744,11 @@ __kuser_cmpxchg:                           @ 0xffff0fc0
         * The kernel itself must perform the operation.
         * A special ghost syscall is used for that (see traps.c).
         */
+       stmfd   sp!, {r7, lr}
+       mov     r7, #0xff00             @ 0xfff0 into r7 for EABI
+       orr     r7, r7, #0xf0
        swi     #0x9ffff0
-       mov     pc, lr
+       ldmfd   sp!, {r7, pc}
 
 #elif __LINUX_ARM_ARCH__ < 6
 
@@ -753,12 +765,18 @@ __kuser_cmpxchg:                          @ 0xffff0fc0
         * exception happening just after the str instruction which would
         * clear the Z flag although the exchange was done.
         */
+#ifdef CONFIG_MMU
        teq     ip, ip                  @ set Z flag
        ldr     ip, [r2]                @ load current val
        add     r3, r2, #1              @ prepare store ptr
        teqeq   ip, r0                  @ compare with oldval if still allowed
        streq   r1, [r3, #-1]!          @ store newval if still allowed
        subs    r0, r2, r3              @ if r2 == r3 the str occured
+#else
+#warning "NPTL on non MMU needs fixing"
+       mov     r0, #-1
+       adds    r0, r0, #0
+#endif
        mov     pc, lr
 
 #else