[PATCH v8 2/9] powerpc: Only use task_struct 'cpu' field on SMP

From: Christophe Leroy
Date: Tue Oct 16 2018 - 01:06:59 EST


When moving to CONFIG_THREAD_INFO_IN_TASK, the thread_info 'cpu' field
gets moved into task_struct and only defined when CONFIG_SMP is set.

This patch ensures that TI_CPU is only used when CONFIG_SMP is set and
that task_struct 'cpu' field is not used directly out of SMP code.

Signed-off-by: Christophe Leroy <christophe.leroy@xxxxxx>
Reviewed-by: Nicholas Piggin <npiggin@xxxxxxxxx>
---
arch/powerpc/kernel/head_fsl_booke.S | 2 ++
arch/powerpc/kernel/misc_32.S | 4 ++++
arch/powerpc/xmon/xmon.c | 2 +-
3 files changed, 7 insertions(+), 1 deletion(-)

diff --git a/arch/powerpc/kernel/head_fsl_booke.S b/arch/powerpc/kernel/head_fsl_booke.S
index e2750b856c8f..05b574f416b3 100644
--- a/arch/powerpc/kernel/head_fsl_booke.S
+++ b/arch/powerpc/kernel/head_fsl_booke.S
@@ -243,8 +243,10 @@ set_ivor:
li r0,0
stwu r0,THREAD_SIZE-STACK_FRAME_OVERHEAD(r1)

+#ifdef CONFIG_SMP
CURRENT_THREAD_INFO(r22, r1)
stw r24, TI_CPU(r22)
+#endif

bl early_init

diff --git a/arch/powerpc/kernel/misc_32.S b/arch/powerpc/kernel/misc_32.S
index 695b24a2d954..2f0fe8bfc078 100644
--- a/arch/powerpc/kernel/misc_32.S
+++ b/arch/powerpc/kernel/misc_32.S
@@ -183,10 +183,14 @@ _GLOBAL(low_choose_750fx_pll)
or r4,r4,r5
mtspr SPRN_HID1,r4

+#ifdef CONFIG_SMP
/* Store new HID1 image */
CURRENT_THREAD_INFO(r6, r1)
lwz r6,TI_CPU(r6)
slwi r6,r6,2
+#else
+ li r6, 0
+#endif
addis r6,r6,nap_save_hid1@ha
stw r4,nap_save_hid1@l(r6)

diff --git a/arch/powerpc/xmon/xmon.c b/arch/powerpc/xmon/xmon.c
index 58e67b67a97c..7fb265cca4fb 100644
--- a/arch/powerpc/xmon/xmon.c
+++ b/arch/powerpc/xmon/xmon.c
@@ -2991,7 +2991,7 @@ static void show_task(struct task_struct *tsk)
printf("%px %016lx %6d %6d %c %2d %s\n", tsk,
tsk->thread.ksp,
tsk->pid, tsk->parent->pid,
- state, task_thread_info(tsk)->cpu,
+ state, task_cpu(tsk),
tsk->comm);
}

--
2.13.3