ARM: 8034/1: Disable preemption in iwmmxt_task_enable()

This patch is in preparation for calling the iwmmxt_task_enable()
function with interrupts enabled.

Signed-off-by: Catalin Marinas <catalin.marinas@arm.com>
Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>

1 files changed, 11 insertions, 3 deletions

diff --git a/arch/arm/kernel/iwmmxt.S b/arch/arm/kernel/iwmmxt.S
index a08783823b32..fcb33a70a35f 100644
--- a/arch/arm/kernel/iwmmxt.S
+++ b/arch/arm/kernel/iwmmxt.S
@@ -18,6 +18,7 @@
 #include <asm/ptrace.h>
 #include <asm/thread_info.h>
 #include <asm/asm-offsets.h>
+#include <asm/assembler.h>
 
 #if defined(CONFIG_CPU_PJ4)
 #define PJ4(code...)            code
@@ -65,13 +66,14 @@
  */
 
 ENTRY(iwmmxt_task_enable)
+        inc_preempt_count r10, r3
 
         XSC(mrc p15, 0, r2, c15, c1, 0)
         PJ4(mrc p15, 0, r2, c1, c0, 2)
         @ CP0 and CP1 accessible?
         XSC(tst r2, #0x3)
         PJ4(tst r2, #0xf)
-        movne   pc, lr                          @ if so no business here
+        bne     4f                              @ if so no business here
         @ enable access to CP0 and CP1
         XSC(orr r2, r2, #0x3)
         XSC(mcr p15, 0, r2, c15, c1, 0)
@@ -132,7 +134,7 @@ concan_dump:
         wstrd   wR15, [r1, #MMX_WR15]
 
 2:      teq     r0, #0                          @ anything to load?
-        moveq   pc, lr
+        beq     3f
 
 concan_load:
 
@@ -165,8 +167,14 @@ concan_load:
         @ clear CUP/MUP (only if r1 != 0)
         teq     r1, #0
         mov     r2, #0
-        moveq   pc, lr
+        beq     3f
         tmcr    wCon, r2
+
+3:
+#ifdef CONFIG_PREEMPT_COUNT
+        get_thread_info r10
+#endif
+4:      dec_preempt_count r10, r3
         mov     pc, lr
 
 /*