From patchwork Mon Apr 21 13:00:05 2014 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Anup Patel X-Patchwork-Id: 4024901 Return-Path: X-Original-To: patchwork-linux-arm@patchwork.kernel.org Delivered-To: patchwork-parsemail@patchwork2.web.kernel.org Received: from mail.kernel.org (mail.kernel.org [198.145.19.201]) by patchwork2.web.kernel.org (Postfix) with ESMTP id 985FFBFF02 for ; Mon, 21 Apr 2014 13:09:43 +0000 (UTC) Received: from mail.kernel.org (localhost [127.0.0.1]) by mail.kernel.org (Postfix) with ESMTP id B512D20375 for ; Mon, 21 Apr 2014 13:09:42 +0000 (UTC) Received: from bombadil.infradead.org (bombadil.infradead.org [198.137.202.9]) (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 CC24A202EB for ; Mon, 21 Apr 2014 13:09:41 +0000 (UTC) Received: from localhost ([127.0.0.1] helo=bombadil.infradead.org) by bombadil.infradead.org with esmtp (Exim 4.80.1 #2 (Red Hat Linux)) id 1WcDrk-0008BK-8L; Mon, 21 Apr 2014 13:02:32 +0000 Received: from mail-pb0-f41.google.com ([209.85.160.41]) by bombadil.infradead.org with esmtps (Exim 4.80.1 #2 (Red Hat Linux)) id 1WcDrU-0007gG-8X for linux-arm-kernel@lists.infradead.org; Mon, 21 Apr 2014 13:02:17 +0000 Received: by mail-pb0-f41.google.com with SMTP id jt11so3711673pbb.14 for ; Mon, 21 Apr 2014 06:01:55 -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=2cRL9rH+ePy4DA9Dho22Rc2nh94Gf6f88f5s2NVBUd0=; b=QqpNP0niNO68gpOGVPAyBipqgZwLhy8Rz/l5y4wAv5mIAZqC2+WgN5I6VQaiDq+xgi /9g/nxR31FMpUVPTZFmQ1CnpwtYs7Mj+ECA1Wf/Fh3aYWoIpRsN13yTWlqeXOOBiEwCA dWSPfCRpsJsawoBO5vYF40tRDk4keaXtYaKRMjTKKOw2KoEiMw1GFlK/Vvsb2ITuuu74 RsyUnpNH1f3ne4V43zHnsmRDBLwheepQ1Uwlnoph0owmmV/1iW9+ktIPncptX/sJpC90 lNGRKdEKcpvjoKk0ma5Fo6C7meid4sLLM0ZiHdw/NL5dqilgZmqfDk07YK+8J4gbCwMV qoVg== X-Gm-Message-State: ALoCoQlNZknwGNTevxikvulSsN5afoGXC89CS5u23w8scNh8sS8VhQJdW04skrdAsSEdWCCcK4DH X-Received: by 10.68.233.99 with SMTP id tv3mr1779615pbc.163.1398085315729; Mon, 21 Apr 2014 06:01:55 -0700 (PDT) Received: from pnqlab006.amcc.com ([182.73.239.130]) by mx.google.com with ESMTPSA id iq10sm78049235pbc.14.2014.04.21.06.01.50 for (version=TLSv1.1 cipher=ECDHE-RSA-RC4-SHA bits=128/128); Mon, 21 Apr 2014 06:01:54 -0700 (PDT) From: Anup Patel To: kvmarm@lists.cs.columbia.edu Subject: [PATCH v10 11/12] ARM/ARM64: KVM: Emulate PSCI v0.2 CPU_SUSPEND Date: Mon, 21 Apr 2014 18:30:05 +0530 Message-Id: <1398085206-30555-12-git-send-email-anup.patel@linaro.org> X-Mailer: git-send-email 1.7.9.5 In-Reply-To: <1398085206-30555-1-git-send-email-anup.patel@linaro.org> References: <1398085206-30555-1-git-send-email-anup.patel@linaro.org> X-CRM114-Version: 20100106-BlameMichelson ( TRE 0.8.0 (BSD) ) MR-646709E3 X-CRM114-CacheID: sfid-20140421_060216_399212_0AEC26D6 X-CRM114-Status: GOOD ( 15.16 ) X-Spam-Score: -0.7 (/) Cc: Rob Herring , linaro-kernel@lists.linaro.org, Anup Patel , kvm@vger.kernel.org, Marc Zyngier , patches@apm.com, Ashwin Chaugule , 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=-2.5 required=5.0 tests=BAYES_00,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 we only 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/) For simplicity, we implement CPU_SUSPEND emulation similar to WFI (Wait-for-interrupt) emulation and we also treat power-down request to be same as stand-by request. This is consistent with section 5.4.1 and section 5.4.2 of PSCI v0.2 specification. Signed-off-by: Anup Patel Signed-off-by: Pranavkumar Sawargaonkar Acked-by: Christoffer Dall Acked-by: Marc Zyngier --- arch/arm/kvm/psci.c | 28 ++++++++++++++++++++++++---- 1 file changed, 24 insertions(+), 4 deletions(-) diff --git a/arch/arm/kvm/psci.c b/arch/arm/kvm/psci.c index b582e99..757e506 100644 --- a/arch/arm/kvm/psci.c +++ b/arch/arm/kvm/psci.c @@ -37,6 +37,26 @@ static unsigned long psci_affinity_mask(unsigned long affinity_level) return 0; } +static unsigned long kvm_psci_vcpu_suspend(struct kvm_vcpu *vcpu) +{ + /* + * NOTE: For simplicity, we make VCPU suspend emulation to be + * same-as WFI (Wait-for-interrupt) emulation. + * + * This means for KVM the wakeup events are interrupts and + * this is consistent with intended use of StateID as described + * in section 5.4.1 of PSCI v0.2 specification (ARM DEN 0022A). + * + * Further, we also treat power-down request to be same as + * stand-by request as-per section 5.4.2 clause 3 of PSCI v0.2 + * specification (ARM DEN 0022A). This means all suspend states + * for KVM will preserve the register state. + */ + kvm_vcpu_block(vcpu); + + return PSCI_RET_SUCCESS; +} + static void kvm_psci_vcpu_off(struct kvm_vcpu *vcpu) { vcpu->arch.pause = true; @@ -183,6 +203,10 @@ 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; @@ -221,10 +245,6 @@ static int kvm_psci_0_2_call(struct kvm_vcpu *vcpu) val = PSCI_RET_INTERNAL_FAILURE; 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; }