From nobody Mon Apr 6 23:07:02 2026 Received: from mx0a-001b2d01.pphosted.com (mx0a-001b2d01.pphosted.com [148.163.156.1]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by smtp.subspace.kernel.org (Postfix) with ESMTPS id 43EEE2D780C; Tue, 17 Mar 2026 19:54:52 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=148.163.156.1 ARC-Seal: i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1773777293; cv=none; b=CEreiH6Hs3zUp9C0PTuuTEaQn7oaEz8fk1Dn4IuVSsIe+ls19lEIbbR7Bs3ptBf0EW9Ncr4MfivFwszckA3Xv0U07ZS/RACL4+CUOF1CTWOo3sZje5XLe7CgL5P4UKP6plEBtbhHZD10yaStse79MdseQkW2/oFmTYHV9f+2E/4= ARC-Message-Signature: i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1773777293; c=relaxed/simple; bh=3gl86jo+8bIc3OfiiGsNB4ocleZ/BnIClnxir6Y4Ldk=; h=From:To:Cc:Subject:Date:Message-ID:In-Reply-To:References: MIME-Version; b=qpvFZR1JGuXUIoGydNgM+OCv45/kqOjFIC30EUDVUPjE+OQ+f49inJu4JPOTgWrSGX64fh2wM/thw7eRjPLrw9EaEBvP5460r9GZo/jsahW2Iu+SlPq53qkaKEjTBKNmaa8vpSiA6BsOnpIRbrr9+yvOHgSpdahfmBgx2PGaB2I= ARC-Authentication-Results: i=1; smtp.subspace.kernel.org; dmarc=pass (p=none dis=none) header.from=linux.ibm.com; spf=pass smtp.mailfrom=linux.ibm.com; dkim=pass (2048-bit key) header.d=ibm.com header.i=@ibm.com header.b=j6WB2TVI; arc=none smtp.client-ip=148.163.156.1 Authentication-Results: smtp.subspace.kernel.org; dmarc=pass (p=none dis=none) header.from=linux.ibm.com Authentication-Results: smtp.subspace.kernel.org; spf=pass smtp.mailfrom=linux.ibm.com Authentication-Results: smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=ibm.com header.i=@ibm.com header.b="j6WB2TVI" Received: from pps.filterd (m0353729.ppops.net [127.0.0.1]) by mx0a-001b2d01.pphosted.com (8.18.1.11/8.18.1.11) with ESMTP id 62HJeIwf949953; Tue, 17 Mar 2026 19:54:44 GMT DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=ibm.com; h=cc :content-transfer-encoding:date:from:in-reply-to:message-id :mime-version:references:subject:to; s=pp1; bh=iNCx15pa7MH7X5LzS pxKLgGYfzmW3lUEW/2ZCCL1/kE=; b=j6WB2TVIWdO5S0P/74GY2dOZeTrA4Fyqr lw5LzHVsoilF5VYK7jZGpVnBtWbUICowrhSNNwUz0XyTYZD0Ddqa+Xiz54d8nyT0 3iX7tKl35MxHDb2UGg2Yim/NKFjGsqM5lLSJGwIwyuccb5wnM1NPlD/r15babRBn 7dWgQ6QF0b8sUh0PTQ/x9mrcaFL504XSrTpeZzdHV00yNpUALoviTT6cloytyTvF 1HQrL4fMQgoIK6NmFcNBhh6ktL42KoH1D59wTWZET/7/p+6J7nQjrPgnfAWYSMFd 2q6iUYe4bCgQt0WWR9B5vIB3jQc/LR//UfhP4hJ/scohJ8+rxmlBQ== Received: from ppma21.wdc07v.mail.ibm.com (5b.69.3da9.ip4.static.sl-reverse.com [169.61.105.91]) by mx0a-001b2d01.pphosted.com (PPS) with ESMTPS id 4cvybs6m85-1 (version=TLSv1.2 cipher=ECDHE-RSA-AES256-GCM-SHA384 bits=256 verify=NOT); Tue, 17 Mar 2026 19:54:43 +0000 (GMT) Received: from pps.filterd (ppma21.wdc07v.mail.ibm.com [127.0.0.1]) by ppma21.wdc07v.mail.ibm.com (8.18.1.2/8.18.1.2) with ESMTP id 62HJjO3v015676; Tue, 17 Mar 2026 19:54:42 GMT Received: from smtprelay03.fra02v.mail.ibm.com ([9.218.2.224]) by ppma21.wdc07v.mail.ibm.com (PPS) with ESMTPS id 4cwk0nasq0-1 (version=TLSv1.2 cipher=ECDHE-RSA-AES256-GCM-SHA384 bits=256 verify=NOT); Tue, 17 Mar 2026 19:54:42 +0000 Received: from smtpav01.fra02v.mail.ibm.com (smtpav01.fra02v.mail.ibm.com [10.20.54.100]) by smtprelay03.fra02v.mail.ibm.com (8.14.9/8.14.9/NCO v10.0) with ESMTP id 62HJscLe50987490 (version=TLSv1/SSLv3 cipher=DHE-RSA-AES256-GCM-SHA384 bits=256 verify=OK); Tue, 17 Mar 2026 19:54:38 GMT Received: from smtpav01.fra02v.mail.ibm.com (unknown [127.0.0.1]) by IMSVA (Postfix) with ESMTP id 0DAA52004B; Tue, 17 Mar 2026 19:54:38 +0000 (GMT) Received: from smtpav01.fra02v.mail.ibm.com (unknown [127.0.0.1]) by IMSVA (Postfix) with ESMTP id DA61F2004D; Tue, 17 Mar 2026 19:54:37 +0000 (GMT) Received: from tuxmaker.boeblingen.de.ibm.com (unknown [9.87.85.9]) by smtpav01.fra02v.mail.ibm.com (Postfix) with ESMTP; Tue, 17 Mar 2026 19:54:37 +0000 (GMT) From: Heiko Carstens To: Peter Zijlstra , Alexander Gordeev , Sven Schnelle , Vasily Gorbik , Christian Borntraeger , Juergen Christ Cc: linux-kernel@vger.kernel.org, linux-s390@vger.kernel.org Subject: [PATCH 4/9] s390/percpu: Use new percpu code section for arch_this_cpu_add() Date: Tue, 17 Mar 2026 20:54:31 +0100 Message-ID: <20260317195436.2276810-5-hca@linux.ibm.com> X-Mailer: git-send-email 2.51.0 In-Reply-To: <20260317195436.2276810-1-hca@linux.ibm.com> References: <20260317195436.2276810-1-hca@linux.ibm.com> Precedence: bulk X-Mailing-List: linux-kernel@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Transfer-Encoding: quoted-printable X-TM-AS-GCONF: 00 X-Authority-Analysis: v=2.4 cv=MMttWcZl c=1 sm=1 tr=0 ts=69b9b183 cx=c_pps a=GFwsV6G8L6GxiO2Y/PsHdQ==:117 a=GFwsV6G8L6GxiO2Y/PsHdQ==:17 a=Yq5XynenixoA:10 a=VkNPw1HP01LnGYTKEx00:22 a=RnoormkPH1_aCDwRdu11:22 a=uAbxVGIbfxUO_5tXvNgY:22 a=VnNF1IyMAAAA:8 a=SujZmW7ZfIunUtho7CIA:9 X-Proofpoint-ORIG-GUID: T5ZNf9kT-SlQ1bw49jZC965DXJ2AEaUL X-Proofpoint-Spam-Details-Enc: AW1haW4tMjYwMzE3MDE3NCBTYWx0ZWRfX5mPInKBvsUkp UR5N+l5zSr92h+zISTvrPOlOVHaFkFTXcATCt51x1Fj3aFkxNFgvxnWQhUxoZztFdOJCbjC209O od8QST2M18+fZCsn34dyfRIeZcH7fQn3qqzNryQki2A2PWOFkSRuhJ/uuVkrzVOL39JW1bC1s0O cRORDiVIK0bg2gqANAcWnmhJZTe7BuNP3Yp2HtQPzal70KBXa9MflEiCmyGHfyAq5cjVxhpDNl9 rhhqL4jBqk4iaLQY6UOZRcADRR46aG79VCeyDaApxSx8PeDvbFLxbUyo/54JZ0kTqtArPe82Ixi 2ABgUoFST9AewHT2aQh1+dpJLaD6eu1d2n6OL+ib5eM5ThDMHl5c/RG4nvByl89tAma2b61/MVZ dxZdrr0q6UGvhOQ1aLSCT7hgKJhDitPLVrGGQt3TmFiXfZwngUElb6FnBde1tl0lMa79yCz7MM9 0tceivmIB/WGxpiV+Jw== X-Proofpoint-GUID: T5ZNf9kT-SlQ1bw49jZC965DXJ2AEaUL X-Proofpoint-Virus-Version: vendor=baseguard engine=ICAP:2.0.293,Aquarius:18.0.1143,Hydra:6.1.51,FMLib:17.12.100.49 definitions=2026-03-17_04,2026-03-17_02,2025-10-01_01 X-Proofpoint-Spam-Details: rule=outbound_notspam policy=outbound score=0 suspectscore=0 lowpriorityscore=0 malwarescore=0 spamscore=0 priorityscore=1501 impostorscore=0 adultscore=0 phishscore=0 clxscore=1015 bulkscore=0 classifier=typeunknown authscore=0 authtc= authcc= route=outbound adjust=0 reason=mlx scancount=1 engine=8.22.0-2603050001 definitions=main-2603170174 Content-Type: text/plain; charset="utf-8" Convert arch_this_cpu_add() to make use of the new percpu code section infrastructure. With this the text size of the kernel image is reduced by ~76kb (defconfig). Also more than 5300 generated preempt_schedule_notrace() function calls within the kernel image (modules not counted) are removed. With: DEFINE_PER_CPU(long, foo); void bar(long a) { this_cpu_add(foo, a); } Old arch_this_cpu_add() looks like this: 00000000000000c0 : c0: c0 04 00 00 00 00 jgnop c0 c6: eb 01 03 a8 00 6a asi 936,1 cc: c4 18 00 00 00 00 lgrl %r1,cc ce: R_390_GOTENT foo+0x2 d2: e3 10 03 b8 00 08 ag %r1,952 d8: eb 22 10 00 00 e8 laag %r2,%r2,0(%r1) de: eb ff 03 a8 00 6e alsi 936,-1 e4: a7 a4 00 05 jhe ee e8: c0 f4 00 00 00 00 jg e8 ea: R_390_PC32DBL __s390_indirect_jump_r14+0x2 ee: c0 f4 00 00 00 00 jg ee f0: R_390_PLT32DBL preempt_schedule_notrace+0x2 New arch_this_cpu_add() looks like this: 00000000000000c0 : c0: c0 04 00 00 00 00 jgnop c0 c6: c4 38 00 00 00 00 lgrl %r3,c6 c8: R_390_GOTENT foo+0x2 cc: b9 04 00 43 lgr %r4,%r3 d0: eb 00 43 c0 00 52 mviy 960(%r4),0 d6: e3 40 03 b8 00 08 ag %r4,952 dc: eb 52 40 00 00 e8 laag %r5,%r2,0(%r4) e2: eb 00 03 c0 00 52 mviy 960,0 e8: c0 f4 00 00 00 00 jg e8 ea: R_390_PC32DBL __s390_indirect_jump_r14+0x2 Note that the conditional function call is removed. Signed-off-by: Heiko Carstens --- arch/s390/include/asm/percpu.h | 65 ++++++++++++++++++++++------------ 1 file changed, 43 insertions(+), 22 deletions(-) diff --git a/arch/s390/include/asm/percpu.h b/arch/s390/include/asm/percpu.h index 05eb91428b42..c92b41efbc47 100644 --- a/arch/s390/include/asm/percpu.h +++ b/arch/s390/include/asm/percpu.h @@ -127,28 +127,49 @@ =20 #else /* MARCH_HAS_Z196_FEATURES */ =20 -#define arch_this_cpu_add(pcp, val, op1, op2, szcast) \ -{ \ - typedef typeof(pcp) pcp_op_T__; \ - pcp_op_T__ val__ =3D (val); \ - pcp_op_T__ old__, *ptr__; \ - preempt_disable_notrace(); \ - ptr__ =3D raw_cpu_ptr(&(pcp)); \ - if (__builtin_constant_p(val__) && \ - ((szcast)val__ > -129) && ((szcast)val__ < 128)) { \ - asm volatile( \ - op2 " %[ptr__],%[val__]" \ - : [ptr__] "+Q" (*ptr__) \ - : [val__] "i" ((szcast)val__) \ - : "cc"); \ - } else { \ - asm volatile( \ - op1 " %[old__],%[val__],%[ptr__]" \ - : [old__] "=3Dd" (old__), [ptr__] "+Q" (*ptr__) \ - : [val__] "d" (val__) \ - : "cc"); \ - } \ - preempt_enable_notrace(); \ +#define arch_this_cpu_add(pcp, val, op1, op2, szcast) \ +{ \ + unsigned long lc_pcpr, lc_pcpo; \ + typedef typeof(pcp) pcp_op_T__; \ + pcp_op_T__ val__ =3D (val); \ + pcp_op_T__ old__, *ptr__; \ + \ + lc_pcpr =3D offsetof(struct lowcore, percpu_register); \ + lc_pcpo =3D offsetof(struct lowcore, percpu_offset); \ + ptr__ =3D &(pcp); \ + if (__builtin_constant_p(val__) && \ + ((szcast)val__ > -129) && ((szcast)val__ < 128)) { \ + asm volatile( \ + MVIY_PERCPU("%[disppcpr]", "%[dispaltpcpr]", "%[ptr__]")\ + AG_ALT("%[disppcpo]", "%[dispaltpcpo]", "%[ptr__]") \ + op2 " 0(%[ptr__]),%[val__]\n" \ + MVIY_ALT("%[disppcpr]", "%[dispaltpcpr]", "%%r0") \ + : [ptr__] "+&a" (ptr__), "+m" (*ptr__), \ + "=3Dm" (((struct lowcore *)0)->percpu_register) \ + : [val__] "i" ((szcast)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"); \ + } else { \ + asm volatile( \ + MVIY_PERCPU("%[disppcpr]", "%[dispaltpcpr]", "%[ptr__]")\ + AG_ALT("%[disppcpo]", "%[dispaltpcpo]", "%[ptr__]") \ + op1 " %[old__],%[val__],0(%[ptr__])\n" \ + MVIY_ALT("%[disppcpr]", "%[dispaltpcpr]", "%%r0") \ + : [old__] "=3D&d" (old__), \ + [ptr__] "+&a" (ptr__), "+m" (*ptr__), \ + "=3Dm" (((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"); \ + } \ } =20 #define this_cpu_add_4(pcp, val) arch_this_cpu_add(pcp, val, "laa", "asi",= int) --=20 2.51.0