From patchwork Wed Apr 2 10:42:26 2014 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Anup Patel X-Patchwork-Id: 3928141 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 E1AACBF540 for ; Wed, 2 Apr 2014 11:05:08 +0000 (UTC) Received: from mail.kernel.org (localhost [127.0.0.1]) by mail.kernel.org (Postfix) with ESMTP id 1D2222025B for ; Wed, 2 Apr 2014 11:05:08 +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 D0E092025A for ; Wed, 2 Apr 2014 11:05:06 +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 1WVIfd-0008KU-C1; Wed, 02 Apr 2014 10:45:27 +0000 Received: from localhost ([::1] helo=merlin.infradead.org) by merlin.infradead.org with esmtp (Exim 4.80.1 #2 (Red Hat Linux)) id 1WVIem-0007gW-2b; Wed, 02 Apr 2014 10:44:32 +0000 Received: from mail-pb0-f42.google.com ([209.85.160.42]) by merlin.infradead.org with esmtps (Exim 4.80.1 #2 (Red Hat Linux)) id 1WVIeh-0007cx-K2 for linux-arm-kernel@lists.infradead.org; Wed, 02 Apr 2014 10:44:29 +0000 Received: by mail-pb0-f42.google.com with SMTP id rr13so11328817pbb.15 for ; Wed, 02 Apr 2014 03:44:06 -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=4i8yf3miZtBf1lGh+Idd3eM1qEPGRtgVdEAIX/NI15Y=; b=R1uhgns2CSo6eRvQoM5wX5iFYWQuaXrERV6uegYEZ7aQ1Y01+FmFsOJFf8xbViigHH +5X+vo04VHB14fdMxPBubtNdcc3/E7Rs2bMcc7bUCwrnXXPvsTadLAZbpfz/WfQdpJLS LZZ2ZfMetD6hSQjBqYreeQeyqyhv9mmcUcfsXPi/oDZuxydNXu3C/9tTfhhJZ8UPLcUo co6KqCMCTvlylOGDfq5LDfWWhCkE9BPo7w2zhoEd0yCltf5IuBWhllk/IevwtbeBO5oH ZSIQRoNHWqcw3s+BTayMbNT+SHwyfDdtdg4YB+eLrKVhOcJNI4qdWAcWcmXI47nmOcXC YL3A== X-Gm-Message-State: ALoCoQlJkqYlYUVFxsf++mmcsn7IHiQou3vB4Ser+Z2oDxM0Nc+ydaNycG2otDaeB6V8nHYW2b/o X-Received: by 10.66.227.104 with SMTP id rz8mr37375190pac.74.1396435446303; Wed, 02 Apr 2014 03:44:06 -0700 (PDT) Received: from pnqlab006.amcc.com ([182.73.239.130]) by mx.google.com with ESMTPSA id tk5sm3573403pbc.63.2014.04.02.03.44.01 for (version=TLSv1.1 cipher=ECDHE-RSA-RC4-SHA bits=128/128); Wed, 02 Apr 2014 03:44:05 -0700 (PDT) From: Anup Patel To: kvmarm@lists.cs.columbia.edu Subject: [PATCH v7 11/12] ARM/ARM64: KVM: Emulate PSCI v0.2 CPU_SUSPEND Date: Wed, 2 Apr 2014 16:12:26 +0530 Message-Id: <1396435347-20056-12-git-send-email-anup.patel@linaro.org> X-Mailer: git-send-email 1.7.9.5 In-Reply-To: <1396435347-20056-1-git-send-email-anup.patel@linaro.org> References: <1396435347-20056-1-git-send-email-anup.patel@linaro.org> X-CRM114-Version: 20100106-BlameMichelson ( TRE 0.8.0 (BSD) ) MR-646709E3 X-CRM114-CacheID: sfid-20140402_064427_808342_523CFE25 X-CRM114-Status: GOOD ( 13.09 ) X-Spam-Score: -2.6 (--) Cc: Mark Rutland , Rob Herring , linaro-kernel@lists.linaro.org, Anup Patel , 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=-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 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/) 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 above, 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 also 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 --- arch/arm/kvm/psci.c | 27 +++++++++++++++++++++++---- 1 file changed, 23 insertions(+), 4 deletions(-) diff --git a/arch/arm/kvm/psci.c b/arch/arm/kvm/psci.c index fdbd829..74fa4ad 100644 --- a/arch/arm/kvm/psci.c +++ b/arch/arm/kvm/psci.c @@ -52,6 +52,25 @@ 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 to be + * same-as WFI (Wait-for-interrupt) emulation. This is also + * 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 PSCI emulation 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; @@ -195,6 +214,10 @@ 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 +255,6 @@ 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; }