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From:   Nicholas Piggin <npiggin@gmail.com>
To:     linux-kernel@vger.kernel.org
Cc:     Nicholas Piggin <npiggin@gmail.com>, linux-arch@vger.kernel.org,
        Peter Zijlstra <peterz@infradead.org>,
        Rik van Riel <riel@surriel.com>,
        Thomas Gleixner <tglx@linutronix.de>,
        Frederic Weisbecker <fweisbec@gmail.com>,
        Sven Schnelle <svens@linux.ibm.com>,
        Arnd Bergmann <arnd@arndb.de>, linuxppc-dev@lists.ozlabs.org,
        linux-s390@vger.kernel.org
Subject: [PATCH] cputime: remove cputime_to_nsecs fallback
Date:   Tue, 20 Dec 2022 17:07:05 +1000
Message-Id: <20221220070705.2958959-1-npiggin@gmail.com>
MIME-Version: 1.0
Content-Transfer-Encoding: 8bit
Precedence: bulk

The archs that use cputime_to_nsecs() internally provide their own
definition and don't need the fallback. cputime_to_usecs() unused except
in this fallback, and is not defined anywhere.

This removes the final remnant of the cputime_t code from the kernel.

Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Rik van Riel <riel@surriel.com>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Frederic Weisbecker <fweisbec@gmail.com>
Cc: Sven Schnelle <svens@linux.ibm.com>
Cc: Arnd Bergmann <arnd@arndb.de>
Cc: linuxppc-dev@lists.ozlabs.org
Cc: linux-s390@vger.kernel.org
Signed-off-by: Nicholas Piggin <npiggin@gmail.com>
---
This required a couple of tweaks to s390 includes so we're not pulling
asm/cputime.h into the core header unnecessarily. In that case maybe
this can go via s390 tree because the patch should be otherwise quite
trivial. Could it get an ack or two from a core maintainer to support
that?

Thanks,
Nick

 arch/s390/kernel/idle.c       | 2 +-
 arch/s390/kernel/vtime.c      | 2 +-
 include/linux/sched/cputime.h | 9 ---------
 kernel/sched/cputime.c        | 4 ++++
 4 files changed, 6 insertions(+), 11 deletions(-)

diff --git a/arch/s390/kernel/idle.c b/arch/s390/kernel/idle.c
index 4bf1ee293f2b..a6bbceaf7616 100644
--- a/arch/s390/kernel/idle.c
+++ b/arch/s390/kernel/idle.c
@@ -12,9 +12,9 @@
 #include <linux/notifier.h>
 #include <linux/init.h>
 #include <linux/cpu.h>
-#include <linux/sched/cputime.h>
 #include <trace/events/power.h>
 #include <asm/cpu_mf.h>
+#include <asm/cputime.h>
 #include <asm/nmi.h>
 #include <asm/smp.h>
 #include "entry.h"
diff --git a/arch/s390/kernel/vtime.c b/arch/s390/kernel/vtime.c
index 9436f3053b88..e0a88dcaf5cb 100644
--- a/arch/s390/kernel/vtime.c
+++ b/arch/s390/kernel/vtime.c
@@ -7,13 +7,13 @@
  */
 
 #include <linux/kernel_stat.h>
-#include <linux/sched/cputime.h>
 #include <linux/export.h>
 #include <linux/kernel.h>
 #include <linux/timex.h>
 #include <linux/types.h>
 #include <linux/time.h>
 #include <asm/alternative.h>
+#include <asm/cputime.h>
 #include <asm/vtimer.h>
 #include <asm/vtime.h>
 #include <asm/cpu_mf.h>
diff --git a/include/linux/sched/cputime.h b/include/linux/sched/cputime.h
index ce3c58286062..5f8fd5b24a2e 100644
--- a/include/linux/sched/cputime.h
+++ b/include/linux/sched/cputime.h
@@ -8,15 +8,6 @@
  * cputime accounting APIs:
  */
 
-#ifdef CONFIG_VIRT_CPU_ACCOUNTING_NATIVE
-#include <asm/cputime.h>
-
-#ifndef cputime_to_nsecs
-# define cputime_to_nsecs(__ct)	\
-	(cputime_to_usecs(__ct) * NSEC_PER_USEC)
-#endif
-#endif /* CONFIG_VIRT_CPU_ACCOUNTING_NATIVE */
-
 #ifdef CONFIG_VIRT_CPU_ACCOUNTING_GEN
 extern bool task_cputime(struct task_struct *t,
 			 u64 *utime, u64 *stime);
diff --git a/kernel/sched/cputime.c b/kernel/sched/cputime.c
index 95fc77853743..af7952f12e6c 100644
--- a/kernel/sched/cputime.c
+++ b/kernel/sched/cputime.c
@@ -3,6 +3,10 @@
  * Simple CPU accounting cgroup controller
  */
 
+#ifdef CONFIG_VIRT_CPU_ACCOUNTING_NATIVE
+ #include <asm/cputime.h>
+#endif
+
 #ifdef CONFIG_IRQ_TIME_ACCOUNTING
 
 /*
-- 
2.37.2