ARM: OMAP5: Switch to THUMB mode if needed on secondary CPU

On my DRA7 system, when the kernel is built in Thumb-2 mode, the secondary CPU
(Cortex A15) fails to come up causing SMP boot on second CPU to timeout. This
seems to be because the CPU is in ARM mode once the ROM hands over control to
the kernel.  Switch to Thumb-2 mode if required once the kernel is control of
secondary CPU. On OMAP4 on the other hand, it appears to be in Thumb-2 mode on
entry so this is not required and SMP boot works as is.

Also corrected a spurious '+' and updated copyright information.

Cc: Santosh Shilimkar <santosh.shilimkar@ti.com>
Cc: Russell King <linux@arm.linux.org.uk>
Cc: Nishanth Menon <nm@ti.com>
Tested-by: Nishanth Menon <nm@ti.com>
Acked-by: Santosh Shilimkar <santosh.shilimkar@ti.com>
Signed-off-by: Joel Fernandes <joelf@ti.com>
Signed-off-by: Tony Lindgren <tony@atomide.com>

diff --git a/arch/arm/mach-omap2/omap-headsmp.S b/arch/arm/mach-omap2/omap-headsmp.S
index 75e92952c18efe3e597791e6798c2ee2ce5969a1..40c5d5f1451cd34b19ebed5e2d58f150f6f4a29d 100644 (file)
--- a/arch/arm/mach-omap2/omap-headsmp.S
+++ b/arch/arm/mach-omap2/omap-headsmp.S
@@ -1,7 +1,7 @@
 /*
  * Secondary CPU startup routine source file.
  *
- * Copyright (C) 2009 Texas Instruments, Inc.
+ * Copyright (C) 2009-2014 Texas Instruments, Inc.
  *
  * Author:
  *      Santosh Shilimkar <santosh.shilimkar@ti.com>
@@ -28,9 +28,13 @@
  * code.  This routine also provides a holding flag into which
  * secondary core is held until we're ready for it to initialise.
  * The primary core will update this flag using a hardware
-+ * register AuxCoreBoot0.
+ * register AuxCoreBoot0.
  */
 ENTRY(omap5_secondary_startup)
+.arm
+THUMB( adr     r9, BSYM(wait)  )       @ CPU may be entered in ARM mode.
+THUMB( bx      r9              )       @ If this is a Thumb-2 kernel,
+THUMB( .thumb                  )       @ switch to Thumb now.
 wait:  ldr     r2, =AUX_CORE_BOOT0_PA  @ read from AuxCoreBoot0
        ldr     r0, [r2]
        mov     r0, r0, lsr #5