From patchwork Fri Jun 22 20:32:15 2018 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Aaron Lindsay X-Patchwork-Id: 10482997 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 AE4C160383 for ; Fri, 22 Jun 2018 20:34:58 +0000 (UTC) Received: from mail.wl.linuxfoundation.org (localhost [127.0.0.1]) by mail.wl.linuxfoundation.org (Postfix) with ESMTP id A236428F51 for ; Fri, 22 Jun 2018 20:34:58 +0000 (UTC) Received: by mail.wl.linuxfoundation.org (Postfix, from userid 486) id 970C52900E; Fri, 22 Jun 2018 20:34:58 +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=-7.8 required=2.0 tests=BAYES_00,DKIM_SIGNED, MAILING_LIST_MULTI, RCVD_IN_DNSWL_HI, T_DKIM_INVALID autolearn=ham version=3.3.1 Received: from lists.gnu.org (lists.gnu.org [208.118.235.17]) (using TLSv1 with cipher AES256-SHA (256/256 bits)) (No client certificate requested) by mail.wl.linuxfoundation.org (Postfix) with ESMTPS id E035E28F51 for ; Fri, 22 Jun 2018 20:34:57 +0000 (UTC) Received: from localhost ([::1]:36076 helo=lists.gnu.org) by lists.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1fWSll-0003nA-4S for patchwork-qemu-devel@patchwork.kernel.org; Fri, 22 Jun 2018 16:34:57 -0400 Received: from eggs.gnu.org ([2001:4830:134:3::10]:54259) by lists.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1fWSjb-00026f-82 for qemu-devel@nongnu.org; Fri, 22 Jun 2018 16:32:44 -0400 Received: from Debian-exim by eggs.gnu.org with spam-scanned (Exim 4.71) (envelope-from ) id 1fWSjZ-0005QJ-MJ for qemu-devel@nongnu.org; Fri, 22 Jun 2018 16:32:43 -0400 Received: from smtp.codeaurora.org ([198.145.29.96]:45100) by eggs.gnu.org with esmtps (TLS1.0:DHE_RSA_AES_256_CBC_SHA1:32) (Exim 4.71) (envelope-from ) id 1fWSjV-0005Ou-0V; Fri, 22 Jun 2018 16:32:37 -0400 Received: by smtp.codeaurora.org (Postfix, from userid 1000) id 1B31060B13; Fri, 22 Jun 2018 20:32:36 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=codeaurora.org; s=default; t=1529699556; bh=InCWDuIij7WtZxZkLbiWmWFvCgJSfZZgl3ZVKcb3qpg=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=JH5uLBgxPclpcqCdK+u869EGUZOlDNtOUGlbVdiTZptDf3Wa6XcrWQLX4kq8Pc6Iv deodsSPbs7DObckvCT0aToq4/fruWN/et68/8LjvQeQTG7qimdpYxRKMITuyFIVux5 PYRpQjfSu8AW0wbNRhsz2YF5vDvyJGAxHm7CpnqE= Received: from mossypile.qualcomm.com (global_nat1_iad_fw.qualcomm.com [129.46.232.65]) (using TLSv1.2 with cipher ECDHE-RSA-AES128-SHA256 (128/128 bits)) (No client certificate requested) (Authenticated sender: alindsay@smtp.codeaurora.org) by smtp.codeaurora.org (Postfix) with ESMTPSA id A16F76063F; Fri, 22 Jun 2018 20:32:34 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=codeaurora.org; s=default; t=1529699555; bh=InCWDuIij7WtZxZkLbiWmWFvCgJSfZZgl3ZVKcb3qpg=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=NqBY7AZf/vaRlo4E6mGxdz3vcrtwrb3FgE8XctZGxfKVNHbCA02NKJEspVAiNALMz oiGK7GtjSVWyRlXrMolTXYl7DVRO9RfRUkL+Y7adV3gnqiqbi3bTGcEaAfUdR3kpr4 e4ssbzpIAYa5PwKwWK/2SsIDyMoY3ltA9MbQUdgE= DMARC-Filter: OpenDMARC Filter v1.3.2 smtp.codeaurora.org A16F76063F Authentication-Results: pdx-caf-mail.web.codeaurora.org; dmarc=none (p=none dis=none) header.from=codeaurora.org Authentication-Results: pdx-caf-mail.web.codeaurora.org; spf=none smtp.mailfrom=alindsay@codeaurora.org From: Aaron Lindsay To: qemu-arm@nongnu.org, Peter Maydell , Alistair Francis , Wei Huang , Peter Crosthwaite Date: Fri, 22 Jun 2018 16:32:15 -0400 Message-Id: <1529699547-17044-2-git-send-email-alindsay@codeaurora.org> X-Mailer: git-send-email 1.9.1 In-Reply-To: <1529699547-17044-1-git-send-email-alindsay@codeaurora.org> References: <1529699547-17044-1-git-send-email-alindsay@codeaurora.org> X-detected-operating-system: by eggs.gnu.org: GNU/Linux 2.2.x-3.x [generic] [fuzzy] X-Received-From: 198.145.29.96 Subject: [Qemu-devel] [PATCH v5 01/13] target/arm: Reorganize PMCCNTR accesses X-BeenThere: qemu-devel@nongnu.org X-Mailman-Version: 2.1.21 Precedence: list List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Cc: Aaron Lindsay , Michael Spradling , qemu-devel@nongnu.org, Digant Desai Errors-To: qemu-devel-bounces+patchwork-qemu-devel=patchwork.kernel.org@nongnu.org Sender: "Qemu-devel" X-Virus-Scanned: ClamAV using ClamSMTP pmccntr_read and pmccntr_write contained duplicate code that was already being handled by pmccntr_sync. Consolidate the duplicated code into two functions: pmccntr_op_start and pmccntr_op_finish. Add a companion to c15_ccnt in CPUARMState so that we can simultaneously save both the architectural register value and the last underlying cycle count - this ensure time isn't lost and will also allow us to access the 'old' architectural register value in order to detect overflows in later patches. Signed-off-by: Aaron Lindsay --- target/arm/cpu.h | 28 ++++++++++----- target/arm/helper.c | 100 ++++++++++++++++++++++++++++------------------------ 2 files changed, 73 insertions(+), 55 deletions(-) diff --git a/target/arm/cpu.h b/target/arm/cpu.h index 8488273..ba2c876 100644 --- a/target/arm/cpu.h +++ b/target/arm/cpu.h @@ -467,10 +467,20 @@ typedef struct CPUARMState { uint64_t oslsr_el1; /* OS Lock Status */ uint64_t mdcr_el2; uint64_t mdcr_el3; - /* If the counter is enabled, this stores the last time the counter - * was reset. Otherwise it stores the counter value + /* Stores the architectural value of the counter *the last time it was + * updated* by pmccntr_op_start. Accesses should always be surrounded + * by pmccntr_op_start/pmccntr_op_finish to guarantee the latest + * architecturally-corect value is being read/set. */ uint64_t c15_ccnt; + /* Stores the delta between the architectural value and the underlying + * cycle count during normal operation. It is used to update c15_ccnt + * to be the correct architectural value before accesses. During + * accesses, c15_ccnt_delta contains the underlying count being used + * for the access, after which it reverts to the delta value in + * pmccntr_op_finish. + */ + uint64_t c15_ccnt_delta; uint64_t pmccfiltr_el0; /* Performance Monitor Filter Register */ uint64_t vpidr_el2; /* Virtualization Processor ID Register */ uint64_t vmpidr_el2; /* Virtualization Multiprocessor ID Register */ @@ -924,15 +934,17 @@ int cpu_arm_signal_handler(int host_signum, void *pinfo, void *puc); /** - * pmccntr_sync + * pmccntr_op_start/finish * @env: CPUARMState * - * Synchronises the counter in the PMCCNTR. This must always be called twice, - * once before any action that might affect the timer and again afterwards. - * The function is used to swap the state of the register if required. - * This only happens when not in user mode (!CONFIG_USER_ONLY) + * Convert the counter in the PMCCNTR between its delta form (the typical mode + * when it's enabled) and the guest-visible value. These two calls must always + * surround any action which might affect the counter, and the return value + * from pmccntr_op_start must be supplied as the second argument to + * pmccntr_op_finish. */ -void pmccntr_sync(CPUARMState *env); +void pmccntr_op_start(CPUARMState *env); +void pmccntr_op_finish(CPUARMState *env); /* SCTLR bit meanings. Several bits have been reused in newer * versions of the architecture; in that case we define constants diff --git a/target/arm/helper.c b/target/arm/helper.c index 1248d84..23b3a16 100644 --- a/target/arm/helper.c +++ b/target/arm/helper.c @@ -1044,28 +1044,53 @@ static inline bool arm_ccnt_enabled(CPUARMState *env) return true; } - -void pmccntr_sync(CPUARMState *env) +/* + * Ensure c15_ccnt is the guest-visible count so that operations such as + * enabling/disabling the counter or filtering, modifying the count itself, + * etc. can be done logically. This is essentially a no-op if the counter is + * not enabled at the time of the call. + */ +void pmccntr_op_start(CPUARMState *env) { - uint64_t temp_ticks; - - temp_ticks = muldiv64(qemu_clock_get_ns(QEMU_CLOCK_VIRTUAL), + uint64_t cycles = 0; + cycles = muldiv64(qemu_clock_get_ns(QEMU_CLOCK_VIRTUAL), ARM_CPU_FREQ, NANOSECONDS_PER_SECOND); - if (env->cp15.c9_pmcr & PMCRD) { - /* Increment once every 64 processor clock cycles */ - temp_ticks /= 64; - } - if (arm_ccnt_enabled(env)) { - env->cp15.c15_ccnt = temp_ticks - env->cp15.c15_ccnt; + uint64_t eff_cycles = cycles; + if (env->cp15.c9_pmcr & PMCRD) { + /* Increment once every 64 processor clock cycles */ + eff_cycles /= 64; + } + + env->cp15.c15_ccnt = eff_cycles - env->cp15.c15_ccnt_delta; + } + env->cp15.c15_ccnt_delta = cycles; +} + +/* + * If PMCCNTR is enabled, recalculate the delta between the clock and the + * guest-visible count. A call to pmccntr_op_finish should follow every call to + * pmccntr_op_start. + */ +void pmccntr_op_finish(CPUARMState *env) +{ + if (arm_ccnt_enabled(env)) { + uint64_t prev_cycles = env->cp15.c15_ccnt_delta; + + if (env->cp15.c9_pmcr & PMCRD) { + /* Increment once every 64 processor clock cycles */ + prev_cycles /= 64; + } + + env->cp15.c15_ccnt_delta = prev_cycles - env->cp15.c15_ccnt; } } static void pmcr_write(CPUARMState *env, const ARMCPRegInfo *ri, uint64_t value) { - pmccntr_sync(env); + pmccntr_op_start(env); if (value & PMCRC) { /* The counter has been reset */ @@ -1076,26 +1101,16 @@ static void pmcr_write(CPUARMState *env, const ARMCPRegInfo *ri, env->cp15.c9_pmcr &= ~0x39; env->cp15.c9_pmcr |= (value & 0x39); - pmccntr_sync(env); + pmccntr_op_finish(env); } static uint64_t pmccntr_read(CPUARMState *env, const ARMCPRegInfo *ri) { - uint64_t total_ticks; - - if (!arm_ccnt_enabled(env)) { - /* Counter is disabled, do not change value */ - return env->cp15.c15_ccnt; - } - - total_ticks = muldiv64(qemu_clock_get_ns(QEMU_CLOCK_VIRTUAL), - ARM_CPU_FREQ, NANOSECONDS_PER_SECOND); - - if (env->cp15.c9_pmcr & PMCRD) { - /* Increment once every 64 processor clock cycles */ - total_ticks /= 64; - } - return total_ticks - env->cp15.c15_ccnt; + uint64_t ret; + pmccntr_op_start(env); + ret = env->cp15.c15_ccnt; + pmccntr_op_finish(env); + return ret; } static void pmselr_write(CPUARMState *env, const ARMCPRegInfo *ri, @@ -1112,22 +1127,9 @@ static void pmselr_write(CPUARMState *env, const ARMCPRegInfo *ri, static void pmccntr_write(CPUARMState *env, const ARMCPRegInfo *ri, uint64_t value) { - uint64_t total_ticks; - - if (!arm_ccnt_enabled(env)) { - /* Counter is disabled, set the absolute value */ - env->cp15.c15_ccnt = value; - return; - } - - total_ticks = muldiv64(qemu_clock_get_ns(QEMU_CLOCK_VIRTUAL), - ARM_CPU_FREQ, NANOSECONDS_PER_SECOND); - - if (env->cp15.c9_pmcr & PMCRD) { - /* Increment once every 64 processor clock cycles */ - total_ticks /= 64; - } - env->cp15.c15_ccnt = total_ticks - value; + pmccntr_op_start(env); + env->cp15.c15_ccnt = value; + pmccntr_op_finish(env); } static void pmccntr_write32(CPUARMState *env, const ARMCPRegInfo *ri, @@ -1140,7 +1142,11 @@ static void pmccntr_write32(CPUARMState *env, const ARMCPRegInfo *ri, #else /* CONFIG_USER_ONLY */ -void pmccntr_sync(CPUARMState *env) +void pmccntr_op_start(CPUARMState *env) +{ +} + +void pmccntr_op_finish(CPUARMState *env) { } @@ -1149,9 +1155,9 @@ void pmccntr_sync(CPUARMState *env) static void pmccfiltr_write(CPUARMState *env, const ARMCPRegInfo *ri, uint64_t value) { - pmccntr_sync(env); + pmccntr_op_start(env); env->cp15.pmccfiltr_el0 = value & 0xfc000000; - pmccntr_sync(env); + pmccntr_op_finish(env); } static void pmcntenset_write(CPUARMState *env, const ARMCPRegInfo *ri,