Revert "arm64: preempt: Fix big-endian when checking preempt count in assembly"

debian/changelog

@@ -77,7 +77,6 @@ linux (4.19.88-1) UNRELEASED; urgency=medium
     - platform/x86: mlx-platform: Fix LED configuration
     - ARM: OMAP1: fix USB configuration for device-only setups
     - RDMA/hns: Fix the bug while use multi-hop of pbl
-    - arm64: preempt: Fix big-endian when checking preempt count in assembly
     - RDMA/vmw_pvrdma: Use atomic memory allocation in create AH
     - PM / AVS: SmartReflex: NULL check before some freeing functions is not needed
     - xfs: zero length symlinks are not valid

debian/patches/debian/Revert-arm64-preempt-Fix-big-endian-when-checking-pr.patch

@@ -0,0 +1,57 @@
+From: Salvatore Bonaccorso <carnil@debian.org>
+Date: Tue, 17 Dec 2019 15:18:10 +0100
+Subject: Revert "arm64: preempt: Fix big-endian when checking preempt count in
+ assembly"
+Bug: https://lore.kernel.org/stable/20191214021403.GA1357@home.goodmis.org/
+
+As reported[1] by Steven Rostedt while updating 4.19-rt, the change
+breaks without having as well 396244692232f ("arm64: preempt: Provide
+our own implementation of asm/preempt.h").
+
+ [1]: <https://lore.kernel.org/stable/20191214021403.GA1357@home.goodmis.org/>
+
+Signed-off-by: Salvatore Bonaccorso <carnil@debian.org>
+---
+ arch/arm64/include/asm/assembler.h | 8 +++++---
+ arch/arm64/kernel/entry.S          | 6 ++++--
+ 2 files changed, 9 insertions(+), 5 deletions(-)
+
+diff --git a/arch/arm64/include/asm/assembler.h b/arch/arm64/include/asm/assembler.h
+index 0c100506a29a..5a97ac853168 100644
+--- a/arch/arm64/include/asm/assembler.h
++++ b/arch/arm64/include/asm/assembler.h
+@@ -683,9 +683,11 @@ USER(\label, ic	ivau, \tmp2)			// invalidate I line PoU
+ 	.macro		if_will_cond_yield_neon
+ #ifdef CONFIG_PREEMPT
+ 	get_thread_info	x0
+-	ldr		x0, [x0, #TSK_TI_PREEMPT]
+-	sub		x0, x0, #PREEMPT_DISABLE_OFFSET
+-	cbz		x0, .Lyield_\@
++	ldr		w1, [x0, #TSK_TI_PREEMPT]
++	ldr		x0, [x0, #TSK_TI_FLAGS]
++	cmp		w1, #PREEMPT_DISABLE_OFFSET
++	csel		x0, x0, xzr, eq
++	tbnz		x0, #TIF_NEED_RESCHED, .Lyield_\@	// needs rescheduling?
+ 	/* fall through to endif_yield_neon */
+ 	.subsection	1
+ .Lyield_\@ :
+diff --git a/arch/arm64/kernel/entry.S b/arch/arm64/kernel/entry.S
+index bb6832353045..5f800384cb9a 100644
+--- a/arch/arm64/kernel/entry.S
++++ b/arch/arm64/kernel/entry.S
+@@ -622,8 +622,10 @@ el1_irq:
+ 	irq_handler
+ 
+ #ifdef CONFIG_PREEMPT
+-	ldr	x24, [tsk, #TSK_TI_PREEMPT]	// get preempt count
+-	cbnz	x24, 1f				// preempt count != 0
++	ldr	w24, [tsk, #TSK_TI_PREEMPT]	// get preempt count
++	cbnz	w24, 1f				// preempt count != 0
++	ldr	x0, [tsk, #TSK_TI_FLAGS]	// get flags
++	tbz	x0, #TIF_NEED_RESCHED, 1f	// needs rescheduling?
+ 	bl	el1_preempt
+ 1:
+ #endif
+-- 
+2.24.1
+

debian/patches/series

@@ -101,6 +101,7 @@ bugfix/all/kbuild-include-addtree-remove-quotes-before-matching-path.patch
 debian/revert-objtool-fix-config_stack_validation-y-warning.patch
 bugfix/all/mt76-use-the-correct-hweight8-function.patch
 bugfix/all/rtc-s35390a-set-uie_unsupported.patch
+debian/Revert-arm64-preempt-Fix-big-endian-when-checking-pr.patch
 
 # Miscellaneous features