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[2001:4830:134:3::11]) by mx.google.com with ESMTPS id e7si3183621qkc.73.2018.04.17.13.42.01 for (version=TLS1 cipher=AES128-SHA bits=128/128); Tue, 17 Apr 2018 13:42:01 -0700 (PDT) Received-SPF: pass (google.com: domain of qemu-arm-bounces+alex.bennee=linaro.org@nongnu.org designates 2001:4830:134:3::11 as permitted sender) client-ip=2001:4830:134:3::11; Authentication-Results: mx.google.com; dkim=fail header.i=@codeaurora.org header.s=default header.b=lf68Hf9I; dkim=fail header.i=@codeaurora.org header.s=default header.b=ENMDr/kJ; spf=pass (google.com: domain of qemu-arm-bounces+alex.bennee=linaro.org@nongnu.org designates 2001:4830:134:3::11 as permitted sender) smtp.mailfrom=qemu-arm-bounces+alex.bennee=linaro.org@nongnu.org Received: from localhost ([::1]:33316 helo=lists.gnu.org) by lists.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1f8XQP-0005LN-4T for alex.bennee@linaro.org; Tue, 17 Apr 2018 16:42:01 -0400 Received: from eggs.gnu.org ([2001:4830:134:3::10]:50413) by lists.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1f8XNO-0002mm-2D for qemu-arm@nongnu.org; Tue, 17 Apr 2018 16:38:57 -0400 Received: from Debian-exim by eggs.gnu.org with spam-scanned (Exim 4.71) (envelope-from ) id 1f8XNL-0004Pg-Gm for qemu-arm@nongnu.org; Tue, 17 Apr 2018 16:38:53 -0400 Received: from smtp.codeaurora.org ([198.145.29.96]:39284) by eggs.gnu.org with esmtps (TLS1.0:DHE_RSA_AES_256_CBC_SHA1:32) (Exim 4.71) (envelope-from ) id 1f8XNL-0004Gw-6V; Tue, 17 Apr 2018 16:38:51 -0400 Received: by smtp.codeaurora.org (Postfix, from userid 1000) id 44C1B60F8E; Tue, 17 Apr 2018 20:38:50 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=codeaurora.org; s=default; t=1523997530; bh=0edjnVVvLJ8khr8Ny4HvhkS9SZgXmu9zNR/5y/fdxBw=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=lf68Hf9Ivc/in+CXg0jXycW4DQe9JJ3++1JA3wDJZTGhsJuL/5bOFLNlTCPIMZnww FdIrvrhdbhArdo8KbSS/uNr4/QM0Ox45/5okt81Ojez4Gj5vfAnAzDm+OIpMYVf53P QGE3xIj6/St9ugD3OnHAgUXvHHMVrNtDNKsjBeJs= 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 438DE606AC; Tue, 17 Apr 2018 20:38:48 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=codeaurora.org; s=default; t=1523997529; bh=0edjnVVvLJ8khr8Ny4HvhkS9SZgXmu9zNR/5y/fdxBw=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=ENMDr/kJI/c2JONxMsRFcU6IckEtabm6oRQEq/eO6gW991XvAn9Ag3S2qPkB7qGtq Y01vniVOgfOrDR0b8BHsfDoBwGAV8T6fAztd14TQfP6H3vxFlujMSlIDIBtSuLr9E5 OjSJ9M+p9AJsyMScCGQ1phtWldxFZsIEaLbeu+I8= DMARC-Filter: OpenDMARC Filter v1.3.2 smtp.codeaurora.org 438DE606AC 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: Tue, 17 Apr 2018 16:37:47 -0400 Message-Id: <1523997485-1905-4-git-send-email-alindsay@codeaurora.org> X-Mailer: git-send-email 1.9.1 In-Reply-To: <1523997485-1905-1-git-send-email-alindsay@codeaurora.org> References: <1523997485-1905-1-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-arm] [PATCH v4 03/21] target/arm: Reorganize PMCCNTR accesses X-BeenThere: qemu-arm@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-arm-bounces+alex.bennee=linaro.org@nongnu.org Sender: "Qemu-arm" X-TUID: i0eb3YQyZaxB 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 19a0c03..04041db 100644 --- a/target/arm/cpu.h +++ b/target/arm/cpu.h @@ -454,10 +454,20 @@ 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 */ @@ -890,15 +900,17 @@ 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 83ea8f4..f6269a2 100644 --- a/target/arm/helper.c +++ b/target/arm/helper.c @@ -1000,28 +1000,53 @@ 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 */ @@ -1032,26 +1057,16 @@ 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, @@ -1068,22 +1083,9 @@ 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, @@ -1096,7 +1098,11 @@ 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) { } @@ -1105,9 +1111,9 @@ 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 & 0x7E000000; - pmccntr_sync(env); + pmccntr_op_finish(env); } static void pmcntenset_write(CPUARMState *env, const ARMCPRegInfo *ri, -- Qualcomm Datacenter Technologies as an affiliate of Qualcomm Technologies, Inc. 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