From patchwork Mon Mar 31 10:46:12 2014 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Anup Patel X-Patchwork-Id: 3913511 Return-Path: X-Original-To: patchwork-linux-arm@patchwork.kernel.org Delivered-To: patchwork-parsemail@patchwork1.web.kernel.org Received: from mail.kernel.org (mail.kernel.org [198.145.19.201]) by patchwork1.web.kernel.org (Postfix) with ESMTP id 71C149F357 for ; Mon, 31 Mar 2014 11:36:57 +0000 (UTC) Received: from mail.kernel.org (localhost [127.0.0.1]) by mail.kernel.org (Postfix) with ESMTP id 87E09203AD for ; Mon, 31 Mar 2014 11:36:56 +0000 (UTC) Received: from casper.infradead.org (casper.infradead.org [85.118.1.10]) (using TLSv1.2 with cipher DHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by mail.kernel.org (Postfix) with ESMTPS id 521D120386 for ; Mon, 31 Mar 2014 11:36:54 +0000 (UTC) Received: from merlin.infradead.org ([2001:4978:20e::2]) by casper.infradead.org with esmtps (Exim 4.80.1 #2 (Red Hat Linux)) id 1WUZni-0007bY-2a; Mon, 31 Mar 2014 10:50:46 +0000 Received: from localhost ([::1] helo=merlin.infradead.org) by merlin.infradead.org with esmtp (Exim 4.80.1 #2 (Red Hat Linux)) id 1WUZmx-0004tP-MD; Mon, 31 Mar 2014 10:49:59 +0000 Received: from mail-pd0-f182.google.com ([209.85.192.182]) by merlin.infradead.org with esmtps (Exim 4.80.1 #2 (Red Hat Linux)) id 1WUZl9-0004hb-8g for linux-arm-kernel@lists.infradead.org; Mon, 31 Mar 2014 10:48:08 +0000 Received: by mail-pd0-f182.google.com with SMTP id y10so7766763pdj.41 for ; Mon, 31 Mar 2014 03:47:45 -0700 (PDT) X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20130820; h=x-gm-message-state:from:to:cc:subject:date:message-id:in-reply-to :references; bh=1b53nSVwMk55jB+HqdImY8MHzhI+O9XewKXkurXFgvg=; b=GgDjb2o4lZY+WMe4QyS7kapQB3t+lrXWfx26Wu0Odj9DlZiXEZe8qjyUCzy3RrEz4m 3qIIdyGWjb9eY2Xx8qf5mSlNCCyBQmFursY1SjnDLNmWrMgnjweBeO+lZ6Et/cUCaw1f xzou6sXz/KoWQ/AN7/Tz2M++yEE9ROi2/FFT66xxJ2TDymoKBHGBtg0CZa4EkDHadAit 1qcEPATZhwm8tpPp3FnLtS89Cv6x8HPq6S+JhL+SG8/2O2V8BpgS7w4jtfF6AKUfh/b5 ZiNJtH2qVN+0pmQcfalKGaT8tieei1JMPGLSkVVBHmmf5mFX1oDaqygSMOPAWzOS9Wpy gbaA== X-Gm-Message-State: ALoCoQmom71mxvyCIFfcY7nO2TeVweMdge3PlM982RLwX55qWQtVMzn+WMzuZTij+Z6p/OyrxWdO X-Received: by 10.66.27.202 with SMTP id v10mr5802812pag.127.1396262865748; Mon, 31 Mar 2014 03:47:45 -0700 (PDT) Received: from pnqlab006.amcc.com ([182.73.239.130]) by mx.google.com with ESMTPSA id oa3sm42582874pbb.15.2014.03.31.03.47.40 for (version=TLSv1.1 cipher=ECDHE-RSA-RC4-SHA bits=128/128); Mon, 31 Mar 2014 03:47:44 -0700 (PDT) From: Anup Patel To: kvmarm@lists.cs.columbia.edu Subject: [PATCH v6 11/12] ARM/ARM64: KVM: Emulate PSCI v0.2 CPU_SUSPEND Date: Mon, 31 Mar 2014 16:16:12 +0530 Message-Id: <1396262773-7723-12-git-send-email-anup.patel@linaro.org> X-Mailer: git-send-email 1.7.9.5 In-Reply-To: <1396262773-7723-1-git-send-email-anup.patel@linaro.org> References: <1396262773-7723-1-git-send-email-anup.patel@linaro.org> X-CRM114-Version: 20100106-BlameMichelson ( TRE 0.8.0 (BSD) ) MR-646709E3 X-CRM114-CacheID: sfid-20140331_064807_427878_6BB95CCC X-CRM114-Status: GOOD ( 12.66 ) X-Spam-Score: -1.9 (-) Cc: Mark Rutland , Rob Herring , linaro-kernel@lists.linaro.org, Anup Patel , Marc Zyngier , patches@apm.com, linux-arm-kernel@lists.infradead.org, Christoffer Dall , Pranavkumar Sawargaonkar X-BeenThere: linux-arm-kernel@lists.infradead.org X-Mailman-Version: 2.1.15 Precedence: list List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , MIME-Version: 1.0 Sender: "linux-arm-kernel" Errors-To: linux-arm-kernel-bounces+patchwork-linux-arm=patchwork.kernel.org@lists.infradead.org X-Spam-Status: No, score=-4.8 required=5.0 tests=BAYES_00, RCVD_IN_DNSWL_MED, RP_MATCHES_RCVD, UNPARSEABLE_RELAY autolearn=unavailable version=3.3.1 X-Spam-Checker-Version: SpamAssassin 3.3.1 (2010-03-16) on mail.kernel.org X-Virus-Scanned: ClamAV using ClamSMTP This patch adds emulation of PSCI v0.2 CPU_SUSPEND function call for KVM ARM/ARM64. This is a CPU-level function call which can suspend current CPU or current CPU cluster. We don't have VCPU clusters in KVM so for KVM we simply suspend the current VCPU. The CPU_SUSPEND emulation is not tested much because currently there is no CPUIDLE driver in Linux kernel that uses PSCI CPU_SUSPEND. The PSCI CPU_SUSPEND implementation in ARM64 kernel was tested using a Simple CPUIDLE driver which is not published due to unstable DT-bindings for PSCI. (For more info, http://lwn.net/Articles/574950/) Even if we had stable DT-bindings for PSCI and CPUIDLE driver that uses PSCI CPU_SUSPEND then still we need to define SUSPEND states and WAKEUP events for KVM ARM/ARM64. Due to this, we implement CPU_SUSPEND emulation similar to WFI (Wait-for-interrupt) emulation. Signed-off-by: Anup Patel Signed-off-by: Pranavkumar Sawargaonkar --- arch/arm/kvm/psci.c | 29 +++++++++++++++++++++++++---- 1 file changed, 25 insertions(+), 4 deletions(-) diff --git a/arch/arm/kvm/psci.c b/arch/arm/kvm/psci.c index 85bf896..f414fd3 100644 --- a/arch/arm/kvm/psci.c +++ b/arch/arm/kvm/psci.c @@ -52,6 +52,27 @@ static unsigned long psci_affinity_mask(unsigned long affinity_level) return affinity_mask; } +static unsigned long kvm_psci_vcpu_suspend(struct kvm_vcpu *vcpu) +{ + /* + * NOTE: Currently, we don't have any wakeup events for KVM + * so for simplicity we make VCPU suspend emulation same-as + * WFI (Wait-for-interrupt) emulation. + * + * To do this we simply update VCPU registers as-per state + * info provided via r1 - r3 (or x1 - x3) and block the + * VCPU for irqs. + */ + if (*vcpu_reg(vcpu, 1) & (0x1UL << 16)) { + /* Update return pc and r0 for power-down state. */ + *vcpu_pc(vcpu) = *vcpu_reg(vcpu, 2); + *vcpu_reg(vcpu, 0) = *vcpu_reg(vcpu, 3); + } + kvm_vcpu_block(vcpu); + + return PSCI_RET_SUCCESS; +} + static void kvm_psci_vcpu_off(struct kvm_vcpu *vcpu) { vcpu->arch.pause = true; @@ -195,6 +216,10 @@ static int kvm_psci_0_2_call(struct kvm_vcpu *vcpu) */ val = 2; break; + case PSCI_0_2_FN_CPU_SUSPEND: + case PSCI_0_2_FN64_CPU_SUSPEND: + val = kvm_psci_vcpu_suspend(vcpu); + break; case PSCI_0_2_FN_CPU_OFF: kvm_psci_vcpu_off(vcpu); val = PSCI_RET_SUCCESS; @@ -232,10 +257,6 @@ static int kvm_psci_0_2_call(struct kvm_vcpu *vcpu) val = PSCI_RET_SUCCESS; ret = 0; break; - case PSCI_0_2_FN_CPU_SUSPEND: - case PSCI_0_2_FN64_CPU_SUSPEND: - val = PSCI_RET_NOT_SUPPORTED; - break; default: return -EINVAL; }