From: David Woodhouse <dwmw2@infradead.org> To: linux-arm-kernel@lists.infradead.org, kvm@vger.kernel.org Cc: Paolo Bonzini <pbonzini@redhat.com>, Jonathan Corbet <corbet@lwn.net>, Marc Zyngier <maz@kernel.org>, Oliver Upton <oliver.upton@linux.dev>, James Morse <james.morse@arm.com>, Suzuki K Poulose <suzuki.poulose@arm.com>, Zenghui Yu <yuzenghui@huawei.com>, Catalin Marinas <catalin.marinas@arm.com>, Will Deacon <will@kernel.org>, Mark Rutland <mark.rutland@arm.com>, Lorenzo Pieralisi <lpieralisi@kernel.org>, "Rafael J. Wysocki" <rafael@kernel.org>, Len Brown <len.brown@intel.com>, Pavel Machek <pavel@ucw.cz>, David Woodhouse <dwmw@amazon.co.uk>, Mostafa Saleh <smostafa@google.com>, Jean-Philippe Brucker <jean-philippe@linaro.org>, linux-doc@vger.kernel.org, linux-kernel@vger.kernel.org, kvmarm@lists.linux.dev, linux-pm@vger.kernel.org Subject: [RFC PATCH 2/2] arm64: Use SYSTEM_OFF2 PSCI call to power off for hibernate Date: Tue, 12 Mar 2024 13:51:29 +0000 [thread overview] Message-ID: <20240312135958.727765-3-dwmw2@infradead.org> (raw) In-Reply-To: <20240312135958.727765-1-dwmw2@infradead.org> From: David Woodhouse <dwmw@amazon.co.uk> The PSCI v1.3 specification (alpha) 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 <dwmw@amazon.co.uk> --- drivers/firmware/psci/psci.c | 35 +++++++++++++++++++++++++++++++++++ kernel/power/hibernate.c | 5 ++++- 2 files changed, 39 insertions(+), 1 deletion(-) diff --git a/drivers/firmware/psci/psci.c b/drivers/firmware/psci/psci.c index d9629ff87861..69d2f6969438 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_supported; static inline bool psci_has_ext_power_state(void) { @@ -333,6 +334,28 @@ 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) +{ + if (system_entering_hibernation()) + invoke_psci_fn(PSCI_FN_NATIVE(1_3, SYSTEM_OFF2), + PSCI_1_3_HIBERNATE_TYPE_OFF, 0, 0); + return NOTIFY_DONE; +} + +static int __init psci_hibernate_init(void) +{ + if (psci_system_off2_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 +387,7 @@ 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) @@ -523,6 +547,16 @@ 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 != PSCI_RET_NOT_SUPPORTED) + psci_system_off2_supported = true; +} + static void __init psci_init_system_suspend(void) { int ret; @@ -653,6 +687,7 @@ 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 4b0b7cf2e019..ac87b3cb670c 100644 --- a/kernel/power/hibernate.c +++ b/kernel/power/hibernate.c @@ -676,8 +676,11 @@ 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(); -- 2.44.0
WARNING: multiple messages have this Message-ID (diff)
From: David Woodhouse <dwmw2@infradead.org> To: linux-arm-kernel@lists.infradead.org, kvm@vger.kernel.org Cc: Paolo Bonzini <pbonzini@redhat.com>, Jonathan Corbet <corbet@lwn.net>, Marc Zyngier <maz@kernel.org>, Oliver Upton <oliver.upton@linux.dev>, James Morse <james.morse@arm.com>, Suzuki K Poulose <suzuki.poulose@arm.com>, Zenghui Yu <yuzenghui@huawei.com>, Catalin Marinas <catalin.marinas@arm.com>, Will Deacon <will@kernel.org>, Mark Rutland <mark.rutland@arm.com>, Lorenzo Pieralisi <lpieralisi@kernel.org>, "Rafael J. Wysocki" <rafael@kernel.org>, Len Brown <len.brown@intel.com>, Pavel Machek <pavel@ucw.cz>, David Woodhouse <dwmw@amazon.co.uk>, Mostafa Saleh <smostafa@google.com>, Jean-Philippe Brucker <jean-philippe@linaro.org>, linux-doc@vger.kernel.org, linux-kernel@vger.kernel.org, kvmarm@lists.linux.dev, linux-pm@vger.kernel.org Subject: [RFC PATCH 2/2] arm64: Use SYSTEM_OFF2 PSCI call to power off for hibernate Date: Tue, 12 Mar 2024 13:51:29 +0000 [thread overview] Message-ID: <20240312135958.727765-3-dwmw2@infradead.org> (raw) In-Reply-To: <20240312135958.727765-1-dwmw2@infradead.org> From: David Woodhouse <dwmw@amazon.co.uk> The PSCI v1.3 specification (alpha) 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 <dwmw@amazon.co.uk> --- drivers/firmware/psci/psci.c | 35 +++++++++++++++++++++++++++++++++++ kernel/power/hibernate.c | 5 ++++- 2 files changed, 39 insertions(+), 1 deletion(-) diff --git a/drivers/firmware/psci/psci.c b/drivers/firmware/psci/psci.c index d9629ff87861..69d2f6969438 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_supported; static inline bool psci_has_ext_power_state(void) { @@ -333,6 +334,28 @@ 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) +{ + if (system_entering_hibernation()) + invoke_psci_fn(PSCI_FN_NATIVE(1_3, SYSTEM_OFF2), + PSCI_1_3_HIBERNATE_TYPE_OFF, 0, 0); + return NOTIFY_DONE; +} + +static int __init psci_hibernate_init(void) +{ + if (psci_system_off2_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 +387,7 @@ 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) @@ -523,6 +547,16 @@ 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 != PSCI_RET_NOT_SUPPORTED) + psci_system_off2_supported = true; +} + static void __init psci_init_system_suspend(void) { int ret; @@ -653,6 +687,7 @@ 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 4b0b7cf2e019..ac87b3cb670c 100644 --- a/kernel/power/hibernate.c +++ b/kernel/power/hibernate.c @@ -676,8 +676,11 @@ 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(); -- 2.44.0 _______________________________________________ linux-arm-kernel mailing list linux-arm-kernel@lists.infradead.org http://lists.infradead.org/mailman/listinfo/linux-arm-kernel
next prev parent reply other threads:[~2024-03-12 14:00 UTC|newest] Thread overview: 32+ messages / expand[flat|nested] mbox.gz Atom feed top 2024-03-12 13:51 [RFC PATCH 0/2] Add PSCI v1.3 SYSTEM_OFF2 support for hibernation David Woodhouse 2024-03-12 13:51 ` David Woodhouse 2024-03-12 13:51 ` [RFC PATCH 1/2] KVM: arm64: Add PSCI SYSTEM_OFF2 function " David Woodhouse 2024-03-12 13:51 ` David Woodhouse 2024-03-12 15:36 ` Marc Zyngier 2024-03-12 15:36 ` Marc Zyngier 2024-03-12 17:06 ` David Woodhouse 2024-03-12 17:06 ` David Woodhouse 2024-03-12 15:47 ` Oliver Upton 2024-03-12 15:47 ` Oliver Upton 2024-03-13 12:53 ` David Woodhouse 2024-03-13 12:53 ` David Woodhouse 2024-03-13 19:42 ` Oliver Upton 2024-03-13 19:42 ` Oliver Upton 2024-03-13 23:01 ` David Woodhouse 2024-03-13 23:01 ` David Woodhouse 2024-03-12 13:51 ` David Woodhouse [this message] 2024-03-12 13:51 ` [RFC PATCH 2/2] arm64: Use SYSTEM_OFF2 PSCI call to power off for hibernate David Woodhouse 2024-03-12 15:57 ` Sudeep Holla 2024-03-12 15:57 ` Sudeep Holla 2024-03-12 16:36 ` David Woodhouse 2024-03-12 16:36 ` David Woodhouse 2024-03-13 15:34 ` Sudeep Holla 2024-03-13 15:34 ` Sudeep Holla 2024-03-14 11:09 ` Sudeep Holla 2024-03-14 11:09 ` Sudeep Holla 2024-03-14 11:27 ` David Woodhouse 2024-03-14 11:27 ` David Woodhouse 2024-03-12 15:24 ` [RFC PATCH 0/2] Add PSCI v1.3 SYSTEM_OFF2 support for hibernation Marc Zyngier 2024-03-12 15:24 ` Marc Zyngier 2024-03-12 17:01 ` David Woodhouse 2024-03-12 17:01 ` David Woodhouse
Reply instructions: You may reply publicly to this message via plain-text email using any one of the following methods: * Save the following mbox file, import it into your mail client, and reply-to-all from there: mbox Avoid top-posting and favor interleaved quoting: https://en.wikipedia.org/wiki/Posting_style#Interleaved_style * Reply using the --to, --cc, and --in-reply-to switches of git-send-email(1): git send-email \ --in-reply-to=20240312135958.727765-3-dwmw2@infradead.org \ --to=dwmw2@infradead.org \ --cc=catalin.marinas@arm.com \ --cc=corbet@lwn.net \ --cc=dwmw@amazon.co.uk \ --cc=james.morse@arm.com \ --cc=jean-philippe@linaro.org \ --cc=kvm@vger.kernel.org \ --cc=kvmarm@lists.linux.dev \ --cc=len.brown@intel.com \ --cc=linux-arm-kernel@lists.infradead.org \ --cc=linux-doc@vger.kernel.org \ --cc=linux-kernel@vger.kernel.org \ --cc=linux-pm@vger.kernel.org \ --cc=lpieralisi@kernel.org \ --cc=mark.rutland@arm.com \ --cc=maz@kernel.org \ --cc=oliver.upton@linux.dev \ --cc=pavel@ucw.cz \ --cc=pbonzini@redhat.com \ --cc=rafael@kernel.org \ --cc=smostafa@google.com \ --cc=suzuki.poulose@arm.com \ --cc=will@kernel.org \ --cc=yuzenghui@huawei.com \ /path/to/YOUR_REPLY https://kernel.org/pub/software/scm/git/docs/git-send-email.html * If your mail client supports setting the In-Reply-To header via mailto: links, try the mailto: linkBe sure your reply has a Subject: header at the top and a blank line before the message body.
This is an external index of several public inboxes, see mirroring instructions on how to clone and mirror all data and code used by this external index.