From: Heiko Carstens <hca@linux.ibm.com>
To: Peter Zijlstra <peterz@infradead.org>,
Alexander Gordeev <agordeev@linux.ibm.com>,
Sven Schnelle <svens@linux.ibm.com>,
Vasily Gorbik <gor@linux.ibm.com>,
Christian Borntraeger <borntraeger@linux.ibm.com>,
Juergen Christ <jchrist@linux.ibm.com>
Cc: linux-kernel@vger.kernel.org, linux-s390@vger.kernel.org
Subject: [PATCH 6/9] s390/percpu: Use new percpu code section for arch_this_cpu_[and|or]()
Date: Tue, 17 Mar 2026 20:54:33 +0100 [thread overview]
Message-ID: <20260317195436.2276810-7-hca@linux.ibm.com> (raw)
In-Reply-To: <20260317195436.2276810-1-hca@linux.ibm.com>
Convert arch_this_cpu_[and|or]() to make use of the new percpu code
section infrastructure.
There is no user of this_cpu_and() and only one user of this_cpu_or()
within the kernel. Therefore this conversion has hardly any effect,
and also removes only preempt_schedule_notrace() function call.
Signed-off-by: Heiko Carstens <hca@linux.ibm.com>
---
arch/s390/include/asm/percpu.h | 26 +++++++++++++++++++-------
1 file changed, 19 insertions(+), 7 deletions(-)
diff --git a/arch/s390/include/asm/percpu.h b/arch/s390/include/asm/percpu.h
index 6e932f45f128..f26f03b0889c 100644
--- a/arch/s390/include/asm/percpu.h
+++ b/arch/s390/include/asm/percpu.h
@@ -208,17 +208,29 @@
#define arch_this_cpu_to_op(pcp, val, op) \
{ \
+ unsigned long lc_pcpr, lc_pcpo; \
typedef typeof(pcp) pcp_op_T__; \
pcp_op_T__ val__ = (val); \
pcp_op_T__ old__, *ptr__; \
- preempt_disable_notrace(); \
- ptr__ = raw_cpu_ptr(&(pcp)); \
- asm volatile( \
- op " %[old__],%[val__],%[ptr__]" \
- : [old__] "=d" (old__), [ptr__] "+Q" (*ptr__) \
- : [val__] "d" (val__) \
+ \
+ lc_pcpr = offsetof(struct lowcore, percpu_register); \
+ lc_pcpo = offsetof(struct lowcore, percpu_offset); \
+ ptr__ = &(pcp); \
+ asm_inline volatile( \
+ MVIY_PERCPU("%[disppcpr]", "%[dispaltpcpr]", "%[ptr__]")\
+ AG_ALT("%[disppcpo]", "%[dispaltpcpo]", "%[ptr__]") \
+ op " %[old__],%[val__],0(%[ptr__])\n" \
+ MVIY_ALT("%[disppcpr]", "%[dispaltpcpr]", "%%r0") \
+ : [old__] "=&d" (old__), \
+ [ptr__] "+&a" (ptr__), "+m" (*ptr__), \
+ "=m" (((struct lowcore *)0)->percpu_register) \
+ : [val__] "d" (val__), \
+ [disppcpr] "i" (lc_pcpr), \
+ [disppcpo] "i" (lc_pcpo), \
+ [dispaltpcpr] "i" (lc_pcpr + LOWCORE_ALT_ADDRESS), \
+ [dispaltpcpo] "i" (lc_pcpo + LOWCORE_ALT_ADDRESS), \
+ "m" (((struct lowcore *)0)->percpu_offset) \
: "cc"); \
- preempt_enable_notrace(); \
}
#define this_cpu_and_4(pcp, val) arch_this_cpu_to_op(pcp, val, "lan")
--
2.51.0
next prev parent reply other threads:[~2026-03-17 19:54 UTC|newest]
Thread overview: 12+ messages / expand[flat|nested] mbox.gz Atom feed top
2026-03-17 19:54 [PATCH 0/9] s390: Improve this_cpu operations Heiko Carstens
2026-03-17 19:54 ` [PATCH 1/9] s390/percpu: Provide arch_raw_cpu_ptr() Heiko Carstens
2026-03-17 19:54 ` [PATCH 2/9] s390/alternatives: Add new ALT_TYPE_PERCPU type Heiko Carstens
2026-03-17 19:54 ` [PATCH 3/9] s390/percpu: Infrastructure for more efficient this_cpu operations Heiko Carstens
2026-03-17 19:54 ` [PATCH 4/9] s390/percpu: Use new percpu code section for arch_this_cpu_add() Heiko Carstens
2026-03-17 19:54 ` [PATCH 5/9] s390/percpu: Use new percpu code section for arch_this_cpu_add_return() Heiko Carstens
2026-03-17 19:54 ` Heiko Carstens [this message]
2026-03-17 19:54 ` [PATCH 7/9] s390/percpu: Provide arch_this_cpu_read() implementation Heiko Carstens
2026-03-17 19:54 ` [PATCH 8/9] s390/percpu: Provide arch_this_cpu_write() implementation Heiko Carstens
2026-03-17 19:54 ` [PATCH 9/9] s390/percpu: Remove one and two byte this_cpu operation implementation Heiko Carstens
2026-03-17 21:08 ` [PATCH 0/9] s390: Improve this_cpu operations Peter Zijlstra
2026-03-23 10:26 ` Juergen Christ
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