From patchwork Sat Oct 19 17:15:47 2024 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: David Woodhouse X-Patchwork-Id: 13842851 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org Received: from bombadil.infradead.org (bombadil.infradead.org [198.137.202.133]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by smtp.lore.kernel.org (Postfix) with ESMTPS id CB545D3C923 for ; Sat, 19 Oct 2024 17:29:49 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; q=dns/txt; c=relaxed/relaxed; d=lists.infradead.org; s=bombadil.20210309; h=Sender:List-Subscribe:List-Help :List-Post:List-Archive:List-Unsubscribe:List-Id:Content-Transfer-Encoding: MIME-Version:References:In-Reply-To:Message-ID:Date:Subject:To:From:Reply-To: Cc:Content-Type:Content-ID:Content-Description:Resent-Date:Resent-From: Resent-Sender:Resent-To:Resent-Cc:Resent-Message-ID:List-Owner; bh=T/6p2P3AuQICDZdTmCqeIRHYUbD9P11W996yxXSWcPU=; b=NTRkun6dmrg6PEXec4hgM8r3VY 63HhyQBgy6O/u7Mx5c4Pge0+xob0KZKc0M5Ihf4sjPsSgMaBs2UPKgrPXJgs95SgaHrPIbl4fE5YD Plj8FdCw/4hYtNmwam0J637m0f3xMaz2s/yagLKGgy0zIPJzv1CK4Cnt+/LKKuOTjPfXzCye0nYIg AzaqkQpQGJxBfJkEBdwfHQi650VimM/y1IYsczV9Vv+v21IVzcFAe9dXaNFH54BTUeEOuBLyYbSwt ZCskHR1FDkl/EUL6NoOEaoJOhdg1F17Oa5t4nNJT/lAqEggQbKC9UR+JdYJkxysiivZr3q16ugdZz npSAHrtQ==; Received: from localhost ([::1] helo=bombadil.infradead.org) by bombadil.infradead.org with esmtp (Exim 4.98 #2 (Red Hat Linux)) id 1t2DGm-00000003gjt-1UfS; Sat, 19 Oct 2024 17:29:40 +0000 Received: from casper.infradead.org ([2001:8b0:10b:1236::1]) by bombadil.infradead.org with esmtps (Exim 4.98 #2 (Red Hat Linux)) id 1t2DCP-00000003fcb-3Byz for linux-arm-kernel@bombadil.infradead.org; Sat, 19 Oct 2024 17:25:09 +0000 DKIM-Signature: v=1; a=rsa-sha256; q=dns/txt; c=relaxed/relaxed; d=infradead.org; s=casper.20170209; h=Sender:Content-Transfer-Encoding: MIME-Version:References:In-Reply-To:Message-ID:Date:Subject:To:From:Reply-To: Cc:Content-Type:Content-ID:Content-Description; bh=T/6p2P3AuQICDZdTmCqeIRHYUbD9P11W996yxXSWcPU=; b=aJMdKFy7DJvlTP1XnRcUjL6xbY Q5EoK5K3U51yRlgxxEb40YRiBgw/w7hBzAWytf0A1aXUXARRqTR8mw4PqxNKx+HwUEscYrVaMJ6UG liArW3tl3xOmGMt4Dpt5nfhKf9vp8d8pBn8fEF0P4V48jTe19emOfLUMSKevdrre9oaVr0tzxPX68 KfkJ/EsRHkgLLB5dH7lDB4jVFjJfjpSy7Y5Mw2LDmiGnt1LIQ4CxfZRhtcrH3zNvWAd2AAUQHcieH OM3tssMkLM/axWzt9O7aiyFjtlV312lwVSI0HPBT/9ylp6SB+/poGIBPaux2rtzL8LJBP7GtVHMPr /yWn6Ahw==; Received: from [2001:8b0:10b:1::ebe] (helo=i7.infradead.org) by casper.infradead.org with esmtpsa (Exim 4.98 #2 (Red Hat Linux)) id 1t2DCK-0000000EUiq-3cTV; Sat, 19 Oct 2024 17:25:07 +0000 Received: from dwoodhou by i7.infradead.org with local (Exim 4.97.1 #2 (Red Hat Linux)) id 1t2DCI-00000009TKv-3xjU; Sat, 19 Oct 2024 18:25:02 +0100 From: David Woodhouse To: Paolo Bonzini , Jonathan Corbet , Marc Zyngier , Oliver Upton , James Morse , Suzuki K Poulose , Zenghui Yu , Catalin Marinas , Will Deacon , Mark Rutland , Lorenzo Pieralisi , "Rafael J. Wysocki" , Pavel Machek , Len Brown , Shuah Khan , David Woodhouse , kvm@vger.kernel.org, linux-doc@vger.kernel.org, linux-kernel@vger.kernel.org, linux-arm-kernel@lists.infradead.org, kvmarm@lists.linux.dev, linux-pm@vger.kernel.org, linux-kselftest@vger.kernel.org, Francesco Lavra , Miguel Luis Subject: [PATCH v6 6/6] arm64: Use SYSTEM_OFF2 PSCI call to power off for hibernate Date: Sat, 19 Oct 2024 18:15:47 +0100 Message-ID: <20241019172459.2241939-7-dwmw2@infradead.org> X-Mailer: git-send-email 2.44.0 In-Reply-To: <20241019172459.2241939-1-dwmw2@infradead.org> References: <20241019172459.2241939-1-dwmw2@infradead.org> MIME-Version: 1.0 X-SRS-Rewrite: SMTP reverse-path rewritten from by casper.infradead.org. See http://www.infradead.org/rpr.html X-BeenThere: linux-arm-kernel@lists.infradead.org X-Mailman-Version: 2.1.34 Precedence: list List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Sender: "linux-arm-kernel" Errors-To: linux-arm-kernel-bounces+linux-arm-kernel=archiver.kernel.org@lists.infradead.org From: David Woodhouse The PSCI v1.3 specification adds support for a SYSTEM_OFF2 function which is analogous to ACPI S4 state. This will allow hosting environments to determine that a guest is hibernated rather than just powered off, and handle that state appropriately on subsequent launches. Since commit 60c0d45a7f7a ("efi/arm64: use UEFI for system reset and poweroff") the EFI shutdown method is deliberately preferred over PSCI or other methods. So register a SYS_OFF_MODE_POWER_OFF handler which *only* handles the hibernation, leaving the original PSCI SYSTEM_OFF as a last resort via the legacy pm_power_off function pointer. The hibernation code already exports a system_entering_hibernation() function which is be used by the higher-priority handler to check for hibernation. That existing function just returns the value of a static boolean variable from hibernate.c, which was previously only set in the hibernation_platform_enter() code path. Set the same flag in the simpler code path around the call to kernel_power_off() too. An alternative way to hook SYSTEM_OFF2 into the hibernation code would be to register a platform_hibernation_ops structure with an ->enter() method which makes the new SYSTEM_OFF2 call. But that would have the unwanted side-effect of making hibernation take a completely different code path in hibernation_platform_enter(), invoking a lot of special dpm callbacks. Another option might be to add a new SYS_OFF_MODE_HIBERNATE mode, with fallback to SYS_OFF_MODE_POWER_OFF. Or to use the sys_off_data to indicate whether the power off is for hibernation. But this version works and is relatively simple. Signed-off-by: David Woodhouse Acked-by: Rafael J. Wysocki Acked-by: Catalin Marinas --- drivers/firmware/psci/psci.c | 42 ++++++++++++++++++++++++++++++++++++ kernel/power/hibernate.c | 5 ++++- 2 files changed, 46 insertions(+), 1 deletion(-) diff --git a/drivers/firmware/psci/psci.c b/drivers/firmware/psci/psci.c index 2328ca58bba6..8809455a61a6 100644 --- a/drivers/firmware/psci/psci.c +++ b/drivers/firmware/psci/psci.c @@ -78,6 +78,7 @@ struct psci_0_1_function_ids get_psci_0_1_function_ids(void) static u32 psci_cpu_suspend_feature; static bool psci_system_reset2_supported; +static bool psci_system_off2_hibernate_supported; static inline bool psci_has_ext_power_state(void) { @@ -333,6 +334,33 @@ static void psci_sys_poweroff(void) invoke_psci_fn(PSCI_0_2_FN_SYSTEM_OFF, 0, 0, 0); } +#ifdef CONFIG_HIBERNATION +static int psci_sys_hibernate(struct sys_off_data *data) +{ + /* + * Zero is an acceptable alternative to PSCI_1_3_OFF_TYPE_HIBERNATE_OFF + * and is supported by hypervisors implementing an earlier version + * of the pSCI v1.3 spec. + */ + if (system_entering_hibernation()) + invoke_psci_fn(PSCI_FN_NATIVE(1_3, SYSTEM_OFF2), + 0 /*PSCI_1_3_OFF_TYPE_HIBERNATE_OFF*/, 0, 0); + return NOTIFY_DONE; +} + +static int __init psci_hibernate_init(void) +{ + if (psci_system_off2_hibernate_supported) { + /* Higher priority than EFI shutdown, but only for hibernate */ + register_sys_off_handler(SYS_OFF_MODE_POWER_OFF, + SYS_OFF_PRIO_FIRMWARE + 2, + psci_sys_hibernate, NULL); + } + return 0; +} +subsys_initcall(psci_hibernate_init); +#endif + static int psci_features(u32 psci_func_id) { return invoke_psci_fn(PSCI_1_0_FN_PSCI_FEATURES, @@ -364,6 +392,7 @@ static const struct { PSCI_ID_NATIVE(1_1, SYSTEM_RESET2), PSCI_ID(1_1, MEM_PROTECT), PSCI_ID_NATIVE(1_1, MEM_PROTECT_CHECK_RANGE), + PSCI_ID_NATIVE(1_3, SYSTEM_OFF2), }; static int psci_debugfs_read(struct seq_file *s, void *data) @@ -525,6 +554,18 @@ static void __init psci_init_system_reset2(void) psci_system_reset2_supported = true; } +static void __init psci_init_system_off2(void) +{ + int ret; + + ret = psci_features(PSCI_FN_NATIVE(1_3, SYSTEM_OFF2)); + if (ret < 0) + return; + + if (ret & PSCI_1_3_OFF_TYPE_HIBERNATE_OFF) + psci_system_off2_hibernate_supported = true; +} + static void __init psci_init_system_suspend(void) { int ret; @@ -655,6 +696,7 @@ static int __init psci_probe(void) psci_init_cpu_suspend(); psci_init_system_suspend(); psci_init_system_reset2(); + psci_init_system_off2(); kvm_init_hyp_services(); } diff --git a/kernel/power/hibernate.c b/kernel/power/hibernate.c index e35829d36039..1f87aa01ba44 100644 --- a/kernel/power/hibernate.c +++ b/kernel/power/hibernate.c @@ -685,8 +685,11 @@ static void power_down(void) } fallthrough; case HIBERNATION_SHUTDOWN: - if (kernel_can_power_off()) + if (kernel_can_power_off()) { + entering_platform_hibernation = true; kernel_power_off(); + entering_platform_hibernation = false; + } break; } kernel_halt();