Patch "MIPS: CPS: Stop dangling delay slot from has_mt." has been added to the 4.2-stable tree

Patch "MIPS: CPS: Stop dangling delay slot from has_mt." has been added to the 4.2-stable tree

[gregkh]

This is a note to let you know that I've just added the patch titled

    MIPS: CPS: Stop dangling delay slot from has_mt.

to the 4.2-stable tree which can be found at:
    http://www.kernel.org/git/?p=linux/kernel/git/stable/stable-queue.git;a=summary

The filename of the patch is:
     mips-cps-stop-dangling-delay-slot-from-has_mt.patch
and it can be found in the queue-4.2 subdirectory.

If you, or anyone else, feels it should not be added to the stable tree,
please let <stable@vger.kernel.org> know about it.


>From 1e5fb282f8eda889776ee83f9214d5df9edaa26d Mon Sep 17 00:00:00 2001
From: Paul Burton <paul.burton@imgtec.com>
Date: Wed, 5 Aug 2015 15:42:36 -0700
Subject: MIPS: CPS: Stop dangling delay slot from has_mt.

From: Paul Burton <paul.burton@imgtec.com>

commit 1e5fb282f8eda889776ee83f9214d5df9edaa26d upstream.

The has_mt macro ended with a branch, leaving its callers with a delay
slot that would be executed if Config3.MT is not set. However it would
not be executed if Config3 (or earlier Config registers) don't exist
which makes it somewhat inconsistent at best. Fill the delay slot in the
macro & fix the mips_cps_boot_vpes caller appropriately.

Signed-off-by: Paul Burton <paul.burton@imgtec.com>
Cc: Markos Chandras <markos.chandras@imgtec.com>
Cc: James Hogan <james.hogan@imgtec.com>
Cc: linux-mips@linux-mips.org
Cc: linux-kernel@vger.kernel.org
Patchwork: https://patchwork.linux-mips.org/patch/10865/
Signed-off-by: Ralf Baechle <ralf@linux-mips.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

---
 arch/mips/kernel/cps-vec.S |    4 ++--
 1 file changed, 2 insertions(+), 2 deletions(-)

--- a/arch/mips/kernel/cps-vec.S
+++ b/arch/mips/kernel/cps-vec.S
@@ -39,6 +39,7 @@
 	 mfc0	\dest, CP0_CONFIG, 3
 	andi	\dest, \dest, MIPS_CONF3_MT
 	beqz	\dest, \nomt
+	 nop
 	.endm
 
 .section .text.cps-vec
@@ -226,7 +227,6 @@ LEAF(mips_cps_core_init)
 #ifdef CONFIG_MIPS_MT
 	/* Check that the core implements the MT ASE */
 	has_mt	t0, 3f
-	 nop
 
 	.set	push
 	.set	mips64r2
@@ -310,8 +310,8 @@ LEAF(mips_cps_boot_vpes)
 	PTR_ADDU t0, t0, t1
 
 	/* Calculate this VPEs ID. If the core doesn't support MT use 0 */
+	li	t9, 0
 	has_mt	ta2, 1f
-	 li	t9, 0
 
 	/* Find the number of VPEs present in the core */
 	mfc0	t1, CP0_MVPCONF0


Patches currently in stable-queue which might be from paul.burton@imgtec.com are

queue-4.2/mips-cps-don-t-include-mt-code-in-non-mt-kernels.patch
queue-4.2/mips-cps-ifdef-on-config_mips_mt_smp-rather-than-config_mips_mt.patch
queue-4.2/mips-cps-stop-dangling-delay-slot-from-has_mt.patch