From patchwork Thu Jul 7 07:46:12 2016 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Crystal Wood X-Patchwork-Id: 9217995 Return-Path: Received: from mail.wl.linuxfoundation.org (pdx-wl-mail.web.codeaurora.org [172.30.200.125]) by pdx-korg-patchwork.web.codeaurora.org (Postfix) with ESMTP id 547C7607D9 for ; Thu, 7 Jul 2016 07:48:17 +0000 (UTC) Received: from mail.wl.linuxfoundation.org (localhost [127.0.0.1]) by mail.wl.linuxfoundation.org (Postfix) with ESMTP id 49A2F28786 for ; Thu, 7 Jul 2016 07:48:17 +0000 (UTC) Received: by mail.wl.linuxfoundation.org (Postfix, from userid 486) id 3E39728788; Thu, 7 Jul 2016 07:48:17 +0000 (UTC) X-Spam-Checker-Version: SpamAssassin 3.3.1 (2010-03-16) on pdx-wl-mail.web.codeaurora.org X-Spam-Level: X-Spam-Status: No, score=-4.2 required=2.0 tests=BAYES_00, RCVD_IN_DNSWL_MED autolearn=ham version=3.3.1 Received: from bombadil.infradead.org (bombadil.infradead.org [198.137.202.9]) (using TLSv1.2 with cipher AES128-GCM-SHA256 (128/128 bits)) (No client certificate requested) by mail.wl.linuxfoundation.org (Postfix) with ESMTPS id 9630C28786 for ; Thu, 7 Jul 2016 07:48:16 +0000 (UTC) Received: from localhost ([127.0.0.1] helo=bombadil.infradead.org) by bombadil.infradead.org with esmtp (Exim 4.85_2 #1 (Red Hat Linux)) id 1bL41U-0003gZ-DI; Thu, 07 Jul 2016 07:47:00 +0000 Received: from host.buserror.net ([209.198.135.123]) by bombadil.infradead.org with esmtps (Exim 4.85_2 #1 (Red Hat Linux)) id 1bL419-0003Sd-Os for linux-arm-kernel@lists.infradead.org; Thu, 07 Jul 2016 07:46:40 +0000 Received: from c-75-72-173-242.hsd1.mn.comcast.net ([75.72.173.242] helo=snotra.am.freescale.net) by host.buserror.net with esmtpsa (TLS1.2:ECDHE_RSA_AES_128_CBC_SHA256:128) (Exim 4.84_2) (envelope-from ) id 1bL40o-0001RB-5K; Thu, 07 Jul 2016 02:46:18 -0500 From: Scott Wood To: Catalin Marinas , Will Deacon , Marc Zyngier Date: Thu, 7 Jul 2016 02:46:12 -0500 Message-Id: <1467877572-10817-4-git-send-email-oss@buserror.net> X-Mailer: git-send-email 2.7.4 In-Reply-To: <1467877572-10817-1-git-send-email-oss@buserror.net> References: <1467877572-10817-1-git-send-email-oss@buserror.net> X-SA-Exim-Connect-IP: 75.72.173.242 X-SA-Exim-Mail-From: oss@buserror.net Subject: [PATCH v4 4/4] arm/arm64: arch_timer: Use archdata to indicate vdso suitability X-SA-Exim-Version: 4.2.1 (built Mon, 26 Dec 2011 16:57:07 +0000) X-SA-Exim-Scanned: Yes (on host.buserror.net) X-CRM114-Version: 20100106-BlameMichelson ( TRE 0.8.0 (BSD) ) MR-646709E3 X-CRM114-CacheID: sfid-20160707_004639_940314_84CBA6BF X-CRM114-Status: GOOD ( 16.56 ) X-BeenThere: linux-arm-kernel@lists.infradead.org X-Mailman-Version: 2.1.20 Precedence: list List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Cc: Scott Wood , devicetree@vger.kernel.org, stuart.yoder@nxp.com, linux-arm-kernel@lists.infradead.org, Russell King MIME-Version: 1.0 Sender: "linux-arm-kernel" Errors-To: linux-arm-kernel-bounces+patchwork-linux-arm=patchwork.kernel.org@lists.infradead.org X-Virus-Scanned: ClamAV using ClamSMTP Instead of comparing the name to a magic string, use archdata to explicitly communicate whether the arch timer is suitable for direct vdso access. Signed-off-by: Scott Wood Acked-by: Will Deacon --- v4: new patch I'm putting this after the other patches, in the hopes that if there are issues with this patch, it doesn't hold up the others. arch/arm/Kconfig | 1 + arch/arm/include/asm/clocksource.h | 8 ++++++++ arch/arm/kernel/vdso.c | 2 +- arch/arm64/Kconfig | 1 + arch/arm64/include/asm/clocksource.h | 8 ++++++++ arch/arm64/kernel/vdso.c | 2 +- drivers/clocksource/arm_arch_timer.c | 11 +++-------- 7 files changed, 23 insertions(+), 10 deletions(-) create mode 100644 arch/arm/include/asm/clocksource.h create mode 100644 arch/arm64/include/asm/clocksource.h diff --git a/arch/arm/Kconfig b/arch/arm/Kconfig index 90542db..dcdcd78 100644 --- a/arch/arm/Kconfig +++ b/arch/arm/Kconfig @@ -1,6 +1,7 @@ config ARM bool default y + select ARCH_CLOCKSOURCE_DATA select ARCH_HAS_ATOMIC64_DEC_IF_POSITIVE select ARCH_HAS_DEVMEM_IS_ALLOWED select ARCH_HAS_ELF_RANDOMIZE diff --git a/arch/arm/include/asm/clocksource.h b/arch/arm/include/asm/clocksource.h new file mode 100644 index 0000000..0b350a7 --- /dev/null +++ b/arch/arm/include/asm/clocksource.h @@ -0,0 +1,8 @@ +#ifndef _ASM_CLOCKSOURCE_H +#define _ASM_CLOCKSOURCE_H + +struct arch_clocksource_data { + bool vdso_direct; /* Usable for direct VDSO access? */ +}; + +#endif diff --git a/arch/arm/kernel/vdso.c b/arch/arm/kernel/vdso.c index 994e971..a0affd1 100644 --- a/arch/arm/kernel/vdso.c +++ b/arch/arm/kernel/vdso.c @@ -270,7 +270,7 @@ static bool tk_is_cntvct(const struct timekeeper *tk) if (!IS_ENABLED(CONFIG_ARM_ARCH_TIMER)) return false; - if (strcmp(tk->tkr_mono.clock->name, "arch_sys_counter") != 0) + if (!tk->tkr_mono.clock->archdata.vdso_direct) return false; return true; diff --git a/arch/arm64/Kconfig b/arch/arm64/Kconfig index 5a0a691..24c4b2c 100644 --- a/arch/arm64/Kconfig +++ b/arch/arm64/Kconfig @@ -3,6 +3,7 @@ config ARM64 select ACPI_CCA_REQUIRED if ACPI select ACPI_GENERIC_GSI if ACPI select ACPI_REDUCED_HARDWARE_ONLY if ACPI + select ARCH_CLOCKSOURCE_DATA select ARCH_HAS_DEVMEM_IS_ALLOWED select ARCH_HAS_ATOMIC64_DEC_IF_POSITIVE select ARCH_HAS_ELF_RANDOMIZE diff --git a/arch/arm64/include/asm/clocksource.h b/arch/arm64/include/asm/clocksource.h new file mode 100644 index 0000000..0b350a7 --- /dev/null +++ b/arch/arm64/include/asm/clocksource.h @@ -0,0 +1,8 @@ +#ifndef _ASM_CLOCKSOURCE_H +#define _ASM_CLOCKSOURCE_H + +struct arch_clocksource_data { + bool vdso_direct; /* Usable for direct VDSO access? */ +}; + +#endif diff --git a/arch/arm64/kernel/vdso.c b/arch/arm64/kernel/vdso.c index 9fefb00..ee107f2 100644 --- a/arch/arm64/kernel/vdso.c +++ b/arch/arm64/kernel/vdso.c @@ -201,7 +201,7 @@ up_fail: */ void update_vsyscall(struct timekeeper *tk) { - u32 use_syscall = strcmp(tk->tkr_mono.clock->name, "arch_sys_counter"); + u32 use_syscall = !tk->tkr_mono.clock->archdata.vdso_direct; ++vdso_data->tb_seq_count; smp_wmb(); diff --git a/drivers/clocksource/arm_arch_timer.c b/drivers/clocksource/arm_arch_timer.c index b857027..a5654a4 100644 --- a/drivers/clocksource/arm_arch_timer.c +++ b/drivers/clocksource/arm_arch_timer.c @@ -575,23 +575,18 @@ static void __init arch_counter_register(unsigned type) else arch_timer_read_counter = arch_counter_get_cntpct; + clocksource_counter.archdata.vdso_direct = true; + #ifdef CONFIG_FSL_ERRATUM_A008585 /* * Don't use the vdso fastpath if errata require using * the out-of-line counter accessor. */ if (static_branch_unlikely(&arch_timer_read_ool_enabled)) - clocksource_counter.name = "arch_sys_counter_ool"; + clocksource_counter.archdata.vdso_direct = false; #endif } else { arch_timer_read_counter = arch_counter_get_cntvct_mem; - - /* If the clocksource name is "arch_sys_counter" the - * VDSO will attempt to read the CP15-based counter. - * Ensure this does not happen when CP15-based - * counter is not available. - */ - clocksource_counter.name = "arch_mem_counter"; } start_count = arch_timer_read_counter();