The branch main has been updated by olce: URL: https://cgit.FreeBSD.org/src/commit/?id=fc6d7a7520d00943ab167544b145f404c10b406a
commit fc6d7a7520d00943ab167544b145f404c10b406a Author: Olivier Certner <[email protected]> AuthorDate: 2026-06-02 16:04:55 +0000 Commit: Olivier Certner <[email protected]> CommitDate: 2026-06-22 13:50:03 +0000 acpi: Forbid requesting S4 when S4BIOS is not supported Pending the OS-supported hibernate functionality, prevent requesting S4 when S4BIOS is not supported. To this end, make sure that acpi_supported_stypes[] indicates that POWER_STYPE_FW_HIBERNATE is not supported if 'acpi_s4bios_supported' is false, even if S4 is supported by the platform (which is only a power-down-like state, without any support to save the system image by itself). This will cause requests to enter S4, which are translated to POWER_STYPE_FW_HIBERNATE before reaching acpi_ReqSleepState()/acpi_EnterSleepState(), to fail in this case. Retire the 'hw.acpi.s4bios' sysctl knob, as having it to 0 by default (S4BIOS not supported) or setting it to 0 (default is 1 when S4BIOS is supported) could only lead, on a S4 request, to a power down without any possibility to restore the system (and, since a recent commit, it has not been possible anymore to force it to 1 when S4BIOS is not announced supported in the FACS table, which would cause a failure or a crash). When OS-supported hibernate is introduced, it will become the default hibernate method over S4BIOS, as we have not heard of any semi-recent hardware platform implementing it (and when it is, it usually needs a sufficiently large dedicated slice/partition, and does not use FreeBSD swap slices/partitions). Then, for people still wanting to use S4BIOS on older platforms that support it, the tentative plans are to modify acpiconf(8) to accept '4BIOS' as an argument to '-s', or modify zzz(8) so that one can pass a specific suspension method. Reviewed by: obiwac Event: Halifax Hackathon 202606 Sponsored by: The FreeBSD Foundation Differential Revision: https://reviews.freebsd.org/D57414 --- sys/amd64/acpica/acpi_wakeup.c | 8 ++++++-- sys/dev/acpica/acpi.c | 34 ++++++++-------------------------- sys/dev/acpica/acpivar.h | 8 -------- sys/i386/acpica/acpi_wakeup.c | 8 ++++++-- 4 files changed, 20 insertions(+), 38 deletions(-) diff --git a/sys/amd64/acpica/acpi_wakeup.c b/sys/amd64/acpica/acpi_wakeup.c index 0dd670300da9..3e64e449dbd9 100644 --- a/sys/amd64/acpica/acpi_wakeup.c +++ b/sys/amd64/acpica/acpi_wakeup.c @@ -227,8 +227,12 @@ acpi_sleep_machdep(struct acpi_softc *sc, int state) WAKECODE_FIXUP(wakeup_gdt, uint16_t, pcb->pcb_gdt.rd_limit); WAKECODE_FIXUP(wakeup_gdt + 2, uint64_t, pcb->pcb_gdt.rd_base); - /* Call ACPICA to enter the desired sleep state */ - if (state == ACPI_STATE_S4 && acpi_should_do_s4bios(sc)) + /* + * Call ACPICA to enter the desired sleep state. Currently, + * reaching this code with 'state' being ACPI_STATE_S4 implies + * a S4BIOS request. + */ + if (state == ACPI_STATE_S4) status = AcpiEnterSleepStateS4bios(); else status = AcpiEnterSleepState(state); diff --git a/sys/dev/acpica/acpi.c b/sys/dev/acpica/acpi.c index 9a85a0844de6..7103eea16053 100644 --- a/sys/dev/acpica/acpi.c +++ b/sys/dev/acpica/acpi.c @@ -189,7 +189,6 @@ static void acpi_system_eventhandler_sleep(void *arg, enum power_stype stype); static void acpi_system_eventhandler_wakeup(void *arg, enum power_stype stype); -static int acpi_s4bios_sysctl(SYSCTL_HANDLER_ARGS); static enum power_stype acpi_sstate_to_stype(int sstate); static int acpi_sname_to_sstate(const char *sname); static const char *acpi_sstate_to_sname(int sstate); @@ -626,8 +625,8 @@ acpi_attach(device_t dev) * Mark whether S4BIOS is available according to the FACS, and if it is, * enable it by default. */ - if (AcpiGbl_FACS != NULL && AcpiGbl_FACS->Flags & ACPI_FACS_S4_BIOS_PRESENT) - sc->acpi_s4bios = sc->acpi_s4bios_supported = true; + sc->acpi_s4bios_supported = AcpiGbl_FACS != NULL && + (AcpiGbl_FACS->Flags & ACPI_FACS_S4_BIOS_PRESENT) != 0; /* * Probe all supported ACPI sleep states. Awake (S0) is always supported, @@ -646,6 +645,12 @@ acpi_attach(device_t dev) sc->acpi_supported_stypes[acpi_sstate_to_stype(state)] = true; } } + /* + * Prevent users from requesting firmware-supported image saving if firmware + * does not indicate it as supported. + */ + if (!sc->acpi_s4bios_supported) + sc->acpi_supported_stypes[POWER_STYPE_FW_HIBERNATE] = false; /* * Dispatch the default sleep type to devices. The lid switch is set @@ -758,10 +763,6 @@ acpi_attach(device_t dev) SYSCTL_ADD_INT(&sc->acpi_sysctl_ctx, SYSCTL_CHILDREN(sc->acpi_sysctl_tree), OID_AUTO, "sleep_delay", CTLFLAG_RW, &sc->acpi_sleep_delay, 0, "sleep delay in seconds"); - SYSCTL_ADD_PROC(&sc->acpi_sysctl_ctx, SYSCTL_CHILDREN(sc->acpi_sysctl_tree), - OID_AUTO, "s4bios", CTLTYPE_U8 | CTLFLAG_RW | CTLFLAG_MPSAFE, - sc, 0, acpi_s4bios_sysctl, "CU", - "On hibernate, have the firmware save/restore the machine state (S4BIOS)."); SYSCTL_ADD_BOOL(&sc->acpi_sysctl_ctx, SYSCTL_CHILDREN(sc->acpi_sysctl_tree), OID_AUTO, "s4bios_supported", CTLFLAG_RD, &sc->acpi_s4bios_supported, 0, "Whether firmware supports saving/restoring the machine state (S4BIOS)."); @@ -4488,25 +4489,6 @@ acpiioctl(struct cdev *dev, u_long cmd, caddr_t addr, int flag, struct thread *t return (error); } -static int -acpi_s4bios_sysctl(SYSCTL_HANDLER_ARGS) -{ - struct acpi_softc *const sc = arg1; - bool val; - int error; - - val = sc->acpi_s4bios; - error = sysctl_handle_bool(oidp, &val, 0, req); - if (error != 0 || req->newptr == NULL) - return (error); - - if (val && !sc->acpi_s4bios_supported) - return (EOPNOTSUPP); - sc->acpi_s4bios = val; - - return (0); -} - static int acpi_sname_to_sstate(const char *sname) { diff --git a/sys/dev/acpica/acpivar.h b/sys/dev/acpica/acpivar.h index 476170f5743b..01e7ddcd74cd 100644 --- a/sys/dev/acpica/acpivar.h +++ b/sys/dev/acpica/acpivar.h @@ -68,7 +68,6 @@ struct acpi_softc { enum power_stype acpi_lid_switch_stype; int acpi_standby_sx; - bool acpi_s4bios; bool acpi_s4bios_supported; int acpi_sleep_delay; @@ -517,13 +516,6 @@ acpi_d_state_to_str(int state) return (strs[state]); } -static __inline bool -acpi_should_do_s4bios(struct acpi_softc *sc) -{ - MPASS(!sc->acpi_s4bios || sc->acpi_s4bios_supported); - return (sc->acpi_s4bios); -} - char *acpi_name(ACPI_HANDLE handle); int acpi_avoid(ACPI_HANDLE handle); int acpi_disabled(char *subsys); diff --git a/sys/i386/acpica/acpi_wakeup.c b/sys/i386/acpica/acpi_wakeup.c index b5390f3cd659..f49464e6efb8 100644 --- a/sys/i386/acpica/acpi_wakeup.c +++ b/sys/i386/acpica/acpi_wakeup.c @@ -239,8 +239,12 @@ acpi_sleep_machdep(struct acpi_softc *sc, int state) */ pmap_remap_lowptdi(true); - /* Call ACPICA to enter the desired sleep state */ - if (state == ACPI_STATE_S4 && acpi_should_do_s4bios(sc)) + /* + * Call ACPICA to enter the desired sleep state. Currently, + * reaching this code with 'state' being ACPI_STATE_S4 implies + * a S4BIOS request. + */ + if (state == ACPI_STATE_S4) status = AcpiEnterSleepStateS4bios(); else status = AcpiEnterSleepState(state);
