From patchwork Fri Aug 16 11:16:00 2019 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Christophe Leroy X-Patchwork-Id: 1148155 Return-Path: X-Original-To: patchwork-incoming@ozlabs.org Delivered-To: patchwork-incoming@ozlabs.org Received: from lists.ozlabs.org (lists.ozlabs.org [IPv6:2401:3900:2:1::3]) (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 46918D2RLVz9sML for ; Fri, 16 Aug 2019 21:20:28 +1000 (AEST) Authentication-Results: ozlabs.org; dmarc=none (p=none dis=none) header.from=c-s.fr Authentication-Results: ozlabs.org; dkim=fail reason="signature verification failed" (1024-bit key; unprotected) header.d=c-s.fr header.i=@c-s.fr header.b="iyGheMYs"; dkim-atps=neutral Received: from bilbo.ozlabs.org (lists.ozlabs.org [IPv6:2401:3900:2:1::3]) by lists.ozlabs.org (Postfix) with ESMTP id 46918D1N2WzDrNG for ; Fri, 16 Aug 2019 21:20:28 +1000 (AEST) 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=c-s.fr (client-ip=93.17.236.30; helo=pegase1.c-s.fr; envelope-from=christophe.leroy@c-s.fr; receiver=) Authentication-Results: lists.ozlabs.org; dmarc=none (p=none dis=none) header.from=c-s.fr Authentication-Results: lists.ozlabs.org; dkim=pass (1024-bit key; unprotected) header.d=c-s.fr header.i=@c-s.fr header.b="iyGheMYs"; dkim-atps=neutral Received: from pegase1.c-s.fr (pegase1.c-s.fr [93.17.236.30]) (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 4691392BN8zDrNG for ; Fri, 16 Aug 2019 21:16:05 +1000 (AEST) Received: from localhost (mailhub1-int [192.168.12.234]) by localhost (Postfix) with ESMTP id 4691333mTlz9tyXs; Fri, 16 Aug 2019 13:15:59 +0200 (CEST) Authentication-Results: localhost; dkim=pass reason="1024-bit key; insecure key" header.d=c-s.fr header.i=@c-s.fr header.b=iyGheMYs; dkim-adsp=pass; dkim-atps=neutral X-Virus-Scanned: Debian amavisd-new at c-s.fr Received: from pegase1.c-s.fr ([192.168.12.234]) by localhost (pegase1.c-s.fr [192.168.12.234]) (amavisd-new, port 10024) with ESMTP id Ll52ruOpJIhH; Fri, 16 Aug 2019 13:15:59 +0200 (CEST) Received: from messagerie.si.c-s.fr (messagerie.si.c-s.fr [192.168.25.192]) by pegase1.c-s.fr (Postfix) with ESMTP id 4691332WGcz9tyXr; Fri, 16 Aug 2019 13:15:59 +0200 (CEST) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=c-s.fr; s=mail; t=1565954159; bh=AZa/Vbvz2vvSVzzKeKFOlBKQpBBPn8tg+lwWM3PrWDc=; h=From:Subject:To:Cc:Date:From; b=iyGheMYsJGzG/1XCaE5L9KFLNeNn8MMnG5pDhiaMiUrKrHaRafvaCnhBGvBEOk3/h FV2uv5wOH5ODcEgqywBVQxlG+fDBZNULNMrlbm6Eoao5jGAUvt+IONp52E5r31qm8i 6dTfluEIu4RWdZi24lCbXOkS3z9KABK1NTpKHODQ= Received: from localhost (localhost [127.0.0.1]) by messagerie.si.c-s.fr (Postfix) with ESMTP id BDC338B776; Fri, 16 Aug 2019 13:16:00 +0200 (CEST) X-Virus-Scanned: amavisd-new at c-s.fr Received: from messagerie.si.c-s.fr ([127.0.0.1]) by localhost (messagerie.si.c-s.fr [127.0.0.1]) (amavisd-new, port 10023) with ESMTP id UoPRWb9ooZBL; Fri, 16 Aug 2019 13:16:00 +0200 (CEST) Received: from pc17473vm.idsi0.si.c-s.fr (po15451.idsi0.si.c-s.fr [172.25.230.101]) by messagerie.si.c-s.fr (Postfix) with ESMTP id 97C768B754; Fri, 16 Aug 2019 13:16:00 +0200 (CEST) Received: by pc17473vm.idsi0.si.c-s.fr (Postfix, from userid 0) id 987C5698B9; Fri, 16 Aug 2019 11:16:00 +0000 (UTC) Message-Id: From: Christophe Leroy Subject: [PATCH v2] powerpc/32: Add VDSO version of getcpu To: Benjamin Herrenschmidt , Paul Mackerras , Michael Ellerman Date: Fri, 16 Aug 2019 11:16:00 +0000 (UTC) X-BeenThere: linuxppc-dev@lists.ozlabs.org X-Mailman-Version: 2.1.29 Precedence: list List-Id: Linux on PowerPC Developers Mail List List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Cc: linuxppc-dev@lists.ozlabs.org, linux-kernel@vger.kernel.org Errors-To: linuxppc-dev-bounces+patchwork-incoming=ozlabs.org@lists.ozlabs.org Sender: "Linuxppc-dev" Commit 18ad51dd342a ("powerpc: Add VDSO version of getcpu") added getcpu() for PPC64 only, by making use of a user readable general purpose SPR. PPC32 doesn't have any such SPR, a full system call can still be avoided by implementing a fast system call which reads the CPU id in the task struct and returns immediately without going back in virtual mode. Before the patch, vdsotest reported: getcpu: syscall: 1572 nsec/call getcpu: libc: 1787 nsec/call getcpu: vdso: not tested Now, vdsotest reports: getcpu: syscall: 1582 nsec/call getcpu: libc: 667 nsec/call getcpu: vdso: 368 nsec/call For non SMP, just return CPU id 0 from the VDSO directly. PPC32 doesn't support CONFIG_NUMA so NUMA node is always 0. Signed-off-by: Christophe Leroy --- v2: fixed build error in getcpu.S --- arch/powerpc/include/asm/vdso.h | 2 ++ arch/powerpc/kernel/head_32.h | 13 +++++++++++++ arch/powerpc/kernel/head_booke.h | 11 +++++++++++ arch/powerpc/kernel/vdso32/Makefile | 4 +--- arch/powerpc/kernel/vdso32/getcpu.S | 7 +++++++ arch/powerpc/kernel/vdso32/vdso32.lds.S | 2 -- 6 files changed, 34 insertions(+), 5 deletions(-) diff --git a/arch/powerpc/include/asm/vdso.h b/arch/powerpc/include/asm/vdso.h index b5e1f8f8a05c..adb54782df5f 100644 --- a/arch/powerpc/include/asm/vdso.h +++ b/arch/powerpc/include/asm/vdso.h @@ -16,6 +16,8 @@ /* Define if 64 bits VDSO has procedure descriptors */ #undef VDS64_HAS_DESCRIPTORS +#define NR_MAGIC_FAST_VDSO_SYSCALL 0x789a + #ifndef __ASSEMBLY__ /* Offsets relative to thread->vdso_base */ diff --git a/arch/powerpc/kernel/head_32.h b/arch/powerpc/kernel/head_32.h index 4a692553651f..a2e38b59785a 100644 --- a/arch/powerpc/kernel/head_32.h +++ b/arch/powerpc/kernel/head_32.h @@ -3,6 +3,8 @@ #define __HEAD_32_H__ #include /* for STACK_FRAME_REGS_MARKER */ +#include +#include /* * MSR_KERNEL is > 0x8000 on 4xx/Book-E since it include MSR_CE. @@ -74,7 +76,13 @@ .endm .macro SYSCALL_ENTRY trapno +#ifdef CONFIG_SMP + cmplwi cr0, r0, NR_MAGIC_FAST_VDSO_SYSCALL +#endif mfspr r12,SPRN_SPRG_THREAD +#ifdef CONFIG_SMP + beq- 1f +#endif mfcr r10 lwz r11,TASK_STACK-THREAD(r12) mflr r9 @@ -152,6 +160,11 @@ mtspr SPRN_SRR0,r11 SYNC RFI /* jump to handler, enable MMU */ +#ifdef CONFIG_SMP +1: + lwz r5, TASK_CPU - THREAD(r12) + RFI +#endif .endm /* diff --git a/arch/powerpc/kernel/head_booke.h b/arch/powerpc/kernel/head_booke.h index 2ae635df9026..c534e87cac84 100644 --- a/arch/powerpc/kernel/head_booke.h +++ b/arch/powerpc/kernel/head_booke.h @@ -3,6 +3,8 @@ #define __HEAD_BOOKE_H__ #include /* for STACK_FRAME_REGS_MARKER */ +#include +#include #include #include @@ -104,6 +106,10 @@ FTR_SECTION_ELSE #ifdef CONFIG_KVM_BOOKE_HV ALT_FTR_SECTION_END_IFSET(CPU_FTR_EMB_HV) #endif +#ifdef CONFIG_SMP + cmplwi cr0, r0, NR_MAGIC_FAST_VDSO_SYSCALL + beq- 1f +#endif BOOKE_CLEAR_BTB(r11) lwz r11, TASK_STACK - THREAD(r10) rlwinm r12,r12,0,4,2 /* Clear SO bit in CR */ @@ -176,6 +182,11 @@ ALT_FTR_SECTION_END_IFSET(CPU_FTR_EMB_HV) mtspr SPRN_SRR0,r11 SYNC RFI /* jump to handler, enable MMU */ +#ifdef CONFIG_SMP +1: + lwz r5, TASK_CPU - THREAD(r10) + RFI +#endif .endm /* To handle the additional exception priority levels on 40x and Book-E diff --git a/arch/powerpc/kernel/vdso32/Makefile b/arch/powerpc/kernel/vdso32/Makefile index 06f54d947057..e147bbdc12cd 100644 --- a/arch/powerpc/kernel/vdso32/Makefile +++ b/arch/powerpc/kernel/vdso32/Makefile @@ -2,9 +2,7 @@ # List of files in the vdso, has to be asm only for now -obj-vdso32-$(CONFIG_PPC64) = getcpu.o -obj-vdso32 = sigtramp.o gettimeofday.o datapage.o cacheflush.o note.o \ - $(obj-vdso32-y) +obj-vdso32 = sigtramp.o gettimeofday.o datapage.o cacheflush.o note.o getcpu.o # Build rules diff --git a/arch/powerpc/kernel/vdso32/getcpu.S b/arch/powerpc/kernel/vdso32/getcpu.S index 63e914539e1a..bde226ad904d 100644 --- a/arch/powerpc/kernel/vdso32/getcpu.S +++ b/arch/powerpc/kernel/vdso32/getcpu.S @@ -17,7 +17,14 @@ */ V_FUNCTION_BEGIN(__kernel_getcpu) .cfi_startproc +#if defined(CONFIG_PPC64) mfspr r5,SPRN_SPRG_VDSO_READ +#elif defined(CONFIG_SMP) + li r0, NR_MAGIC_FAST_VDSO_SYSCALL + sc /* returns cpuid in r5, clobbers cr0 and r10-r13 */ +#else + li r5, 0 +#endif cmpwi cr0,r3,0 cmpwi cr1,r4,0 clrlwi r6,r5,16 diff --git a/arch/powerpc/kernel/vdso32/vdso32.lds.S b/arch/powerpc/kernel/vdso32/vdso32.lds.S index 099a6db14e67..663880671e20 100644 --- a/arch/powerpc/kernel/vdso32/vdso32.lds.S +++ b/arch/powerpc/kernel/vdso32/vdso32.lds.S @@ -152,9 +152,7 @@ VERSION __kernel_sync_dicache_p5; __kernel_sigtramp32; __kernel_sigtramp_rt32; -#ifdef CONFIG_PPC64 __kernel_getcpu; -#endif __kernel_time; local: *;