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

This reverts commit 64694b276d74c653051637caa4bfa5e8c27b30ad which is
commit 7faa313f05cad184e8b17750f0cbe5216ac6debb upstream.

Turns out one of the pre-requsite patches wasn't in 4.19.y, so this
patch didn't make sense.  So let's revert it.

Reported-by: Steven Rostedt <rostedt@goodmis.org>
Reported-by: Will Deacon <will@kernel.org>
Cc: Ard Biesheuvel <ard.biesheuvel@linaro.org>
Cc: Kevin Hilman <khilman@baylibre.com>
Cc: Sasha Levin <sashal@kernel.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

diff --git a/arch/arm64/include/asm/assembler.h b/arch/arm64/include/asm/assembler.h
index 0c100506a29aa403b9997f4691db9a5cad5da06c..5a97ac853168222a0525f3a3d5b75aa02d5bb0cf 100644 (file)
--- 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 bb6832353045882738b0e3c292a5f8e0a5bbe64a..5f800384cb9a8c141f97e55b6d3b15a56f31494a 100644 (file)
--- 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