From patchwork Wed Mar 13 03:42:06 2019 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 8bit X-Patchwork-Submitter: Alastair D'Silva X-Patchwork-Id: 1055875 Return-Path: X-Original-To: patchwork-incoming@ozlabs.org Delivered-To: patchwork-incoming@ozlabs.org Received: from lists.ozlabs.org (lists.ozlabs.org [203.11.71.2]) (using TLSv1.3 with cipher TLS_AES_256_GCM_SHA384 (256/256 bits) key-exchange X25519 server-signature RSA-PSS (4096 bits)) (No client certificate requested) by ozlabs.org (Postfix) with ESMTPS id 44JyQL3C2Bz9s4V for ; Wed, 13 Mar 2019 14:44:42 +1100 (AEDT) Authentication-Results: ozlabs.org; dmarc=none (p=none dis=none) header.from=au1.ibm.com Received: from lists.ozlabs.org (lists.ozlabs.org [IPv6:2401:3900:2:1::3]) by lists.ozlabs.org (Postfix) with ESMTP id 44JyQL1wQkzDqKW for ; Wed, 13 Mar 2019 14:44:42 +1100 (AEDT) X-Original-To: linuxppc-dev@lists.ozlabs.org Delivered-To: linuxppc-dev@lists.ozlabs.org Authentication-Results: lists.ozlabs.org; spf=pass (mailfrom) smtp.mailfrom=au1.ibm.com (client-ip=148.163.158.5; helo=mx0a-001b2d01.pphosted.com; envelope-from=alastair@au1.ibm.com; receiver=) Authentication-Results: lists.ozlabs.org; dmarc=none (p=none dis=none) header.from=au1.ibm.com Received: from mx0a-001b2d01.pphosted.com (mx0b-001b2d01.pphosted.com [148.163.158.5]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by lists.ozlabs.org (Postfix) with ESMTPS id 44JyMv26LrzDqHZ for ; Wed, 13 Mar 2019 14:42:35 +1100 (AEDT) Received: from pps.filterd (m0098420.ppops.net [127.0.0.1]) by mx0b-001b2d01.pphosted.com (8.16.0.27/8.16.0.27) with SMTP id x2D3eOWD128302 for ; Tue, 12 Mar 2019 23:42:32 -0400 Received: from e06smtp07.uk.ibm.com (e06smtp07.uk.ibm.com [195.75.94.103]) by mx0b-001b2d01.pphosted.com with ESMTP id 2r6ndc2sr9-1 (version=TLSv1.2 cipher=AES256-GCM-SHA384 bits=256 verify=NOT) for ; Tue, 12 Mar 2019 23:42:32 -0400 Received: from localhost by e06smtp07.uk.ibm.com with IBM ESMTP SMTP Gateway: Authorized Use Only! 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Rao" , linuxppc-dev@lists.ozlabs.org, Andrew Morton Errors-To: linuxppc-dev-bounces+patchwork-incoming=ozlabs.org@lists.ozlabs.org Sender: "Linuxppc-dev" From: Alastair D'Silva When building an LTO kernel, the existing code generates warnings: ./arch/powerpc/include/asm/paca.h:37:30: warning: register of ‘local_paca’ used for multiple global register variables register struct paca_struct *local_paca asm("r13"); ^ ./arch/powerpc/include/asm/paca.h:37:30: note: conflicts with ‘local_paca’ This patch reworks local_paca into an inline getter & setter function, which addresses the warning. Generated ASM from this patch is broadly similar (addresses have changed and the compiler uses different GPRs in some places). Signed-off-by: Alastair D'Silva --- arch/powerpc/include/asm/paca.h | 44 +++++++++++++++++++++++---------- arch/powerpc/kernel/paca.c | 2 +- 2 files changed, 32 insertions(+), 14 deletions(-) diff --git a/arch/powerpc/include/asm/paca.h b/arch/powerpc/include/asm/paca.h index e843bc5d1a0f..9c9e2dea0f9b 100644 --- a/arch/powerpc/include/asm/paca.h +++ b/arch/powerpc/include/asm/paca.h @@ -34,19 +34,6 @@ #include #include -register struct paca_struct *local_paca asm("r13"); - -#if defined(CONFIG_DEBUG_PREEMPT) && defined(CONFIG_SMP) -extern unsigned int debug_smp_processor_id(void); /* from linux/smp.h */ -/* - * Add standard checks that preemption cannot occur when using get_paca(): - * otherwise the paca_struct it points to may be the wrong one just after. - */ -#define get_paca() ((void) debug_smp_processor_id(), local_paca) -#else -#define get_paca() local_paca -#endif - #ifdef CONFIG_PPC_PSERIES #define get_lppaca() (get_paca()->lppaca_ptr) #endif @@ -266,6 +253,37 @@ struct paca_struct { #endif } ____cacheline_aligned; +#if defined(CONFIG_DEBUG_PREEMPT) && defined(CONFIG_SMP) +extern unsigned int debug_smp_processor_id(void); /* from linux/smp.h */ +#endif + +static inline struct paca_struct *get_paca_no_preempt_check(void) +{ + register struct paca_struct *paca asm("r13"); + return paca; +} + +static inline struct paca_struct *get_paca(void) +{ +#if defined(CONFIG_DEBUG_PREEMPT) && defined(CONFIG_SMP) + /* + * Add standard checks that preemption cannot occur when using get_paca(): + * otherwise the paca_struct it points to may be the wrong one just after. + */ + debug_smp_processor_id(); +#endif + return get_paca_no_preempt_check(); +} + +#define local_paca get_paca_no_preempt_check() + +static inline void set_paca(struct paca_struct *new) +{ + register struct paca_struct *paca asm("r13"); + paca = new; +} + + extern void copy_mm_to_paca(struct mm_struct *mm); extern struct paca_struct **paca_ptrs; extern void initialise_paca(struct paca_struct *new_paca, int cpu); diff --git a/arch/powerpc/kernel/paca.c b/arch/powerpc/kernel/paca.c index 913bfca09c4f..ae5c243f9d5a 100644 --- a/arch/powerpc/kernel/paca.c +++ b/arch/powerpc/kernel/paca.c @@ -172,7 +172,7 @@ void __init initialise_paca(struct paca_struct *new_paca, int cpu) void setup_paca(struct paca_struct *new_paca) { /* Setup r13 */ - local_paca = new_paca; + set_paca(new_paca); #ifdef CONFIG_PPC_BOOK3E /* On Book3E, initialize the TLB miss exception frames */