[RFC PATCH 8/8] ARM: rely on core code to keep thread_info::cpu updated
Ard Biesheuvel
ardb at kernel.org
Tue Sep 14 05:10:36 PDT 2021
Now that the core code switched back to using thread_info::cpu to keep
a task's CPU number, we no longer need to keep it in sync explicitly. So
just drop the code that does this.
Signed-off-by: Ard Biesheuvel <ardb at kernel.org>
---
This patch applies onto [0], which we hope to get merged for v5.16
[0] https://git.kernel.org/pub/scm/linux/kernel/git/ardb/linux.git/log/?h=arm32-ti-in-task-v5
arch/arm/include/asm/switch_to.h | 14 --------------
arch/arm/kernel/smp.c | 3 ---
2 files changed, 17 deletions(-)
diff --git a/arch/arm/include/asm/switch_to.h b/arch/arm/include/asm/switch_to.h
index db2be1f6550d..61e4a3c4ca6e 100644
--- a/arch/arm/include/asm/switch_to.h
+++ b/arch/arm/include/asm/switch_to.h
@@ -23,23 +23,9 @@
*/
extern struct task_struct *__switch_to(struct task_struct *, struct thread_info *, struct thread_info *);
-static inline void set_ti_cpu(struct task_struct *p)
-{
-#ifdef CONFIG_THREAD_INFO_IN_TASK
- /*
- * The core code no longer maintains the thread_info::cpu field once
- * CONFIG_THREAD_INFO_IN_TASK is in effect, but we rely on it for
- * raw_smp_processor_id(), which cannot access struct task_struct*
- * directly for reasons of circular #inclusion hell.
- */
- task_thread_info(p)->cpu = p->cpu;
-#endif
-}
-
#define switch_to(prev,next,last) \
do { \
__complete_pending_tlbi(); \
- set_ti_cpu(next); \
if (IS_ENABLED(CONFIG_CURRENT_POINTER_IN_TPIDRURO)) \
__this_cpu_write(__entry_task, next); \
last = __switch_to(prev,task_thread_info(prev), task_thread_info(next)); \
diff --git a/arch/arm/kernel/smp.c b/arch/arm/kernel/smp.c
index cde5b6d8bac5..97ee6b1567e9 100644
--- a/arch/arm/kernel/smp.c
+++ b/arch/arm/kernel/smp.c
@@ -154,9 +154,6 @@ int __cpu_up(unsigned int cpu, struct task_struct *idle)
secondary_data.swapper_pg_dir = get_arch_pgd(swapper_pg_dir);
#endif
secondary_data.task = idle;
- if (IS_ENABLED(CONFIG_THREAD_INFO_IN_TASK))
- task_thread_info(idle)->cpu = cpu;
-
sync_cache_w(&secondary_data);
/*
--
2.30.2
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