From nobody Tue Nov 26 10:34:48 2024 Received: from casper.infradead.org (casper.infradead.org [90.155.50.34]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by smtp.subspace.kernel.org (Postfix) with ESMTPS id BA3011917E6; Sat, 19 Oct 2024 17:25:16 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=90.155.50.34 ARC-Seal: i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1729358718; cv=none; b=Nyj+fFX5rqgMdSbd44wnqr4fGli56antfK0IbL7byuXCJm7wjQIYzu0f9LO9YgZbVB1NuN9Y4K3nMKepQzyn34VfcYNjoyt0dfCLthsdgaIOjzT4SRzqwoJOJmtkN4lOqui9Q7z3ne+f157bUp7LISZjQSI7Xtc/SsZpd3IlH/s= ARC-Message-Signature: i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1729358718; c=relaxed/simple; bh=K2m8obFhWuwPQuikGUdYpspkIHuhwoUO0TZOETINH7I=; h=From:To:Subject:Date:Message-ID:In-Reply-To:References: MIME-Version; b=hlQYFIk3KVTck5f0rCeCAhufN/+fiWco35JUyL98adgJxXZf1GKax9x36k3pin2+gW3OqqPESYrzyudICGHlSc7z05Krc8nJeivwM8HN6tH/nW7bIbsQ/XSbR4Kq+rqa7K4kOo6ChpZ6Usy8xB4OAm/hgZI3qAgkl0jpfVsZUbA= ARC-Authentication-Results: i=1; smtp.subspace.kernel.org; dmarc=none (p=none dis=none) header.from=infradead.org; spf=none smtp.mailfrom=casper.srs.infradead.org; dkim=pass (2048-bit key) header.d=infradead.org header.i=@infradead.org header.b=aJMdKFy7; arc=none smtp.client-ip=90.155.50.34 Authentication-Results: smtp.subspace.kernel.org; dmarc=none (p=none dis=none) header.from=infradead.org Authentication-Results: smtp.subspace.kernel.org; spf=none smtp.mailfrom=casper.srs.infradead.org Authentication-Results: smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=infradead.org header.i=@infradead.org header.b="aJMdKFy7" 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> Precedence: bulk X-Mailing-List: linux-kernel@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Transfer-Encoding: quoted-printable Sender: David Woodhouse X-SRS-Rewrite: SMTP reverse-path rewritten from by casper.infradead.org. See http://www.infradead.org/rpr.html Content-Type: text/plain; charset="utf-8" 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(vo= id) =20 static u32 psci_cpu_suspend_feature; static bool psci_system_reset2_supported; +static bool psci_system_off2_hibernate_supported; =20 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); } =20 +#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), }; =20 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 =3D true; } =20 +static void __init psci_init_system_off2(void) +{ + int ret; + + ret =3D 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 =3D 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(); } =20 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 =3D true; kernel_power_off(); + entering_platform_hibernation =3D false; + } break; } kernel_halt(); --=20 2.44.0