diff options
| -rw-r--r-- | Documentation/kernel-parameters.txt | 14 | ||||
| -rw-r--r-- | arch/ia64/hp/common/sba_iommu.c | 64 | ||||
| -rw-r--r-- | arch/x86/Kconfig | 1 | ||||
| -rw-r--r-- | arch/x86/boot/compressed/aslr.c | 9 | ||||
| -rw-r--r-- | drivers/acpi/acpi_lpss.c | 15 | ||||
| -rw-r--r-- | drivers/acpi/battery.c | 39 | ||||
| -rw-r--r-- | drivers/acpi/osl.c | 3 | ||||
| -rw-r--r-- | drivers/acpi/tables.c | 3 | ||||
| -rw-r--r-- | drivers/cpufreq/Kconfig | 2 | ||||
| -rw-r--r-- | drivers/cpufreq/cpufreq.c | 10 | ||||
| -rw-r--r-- | drivers/cpufreq/intel_pstate.c | 5 | ||||
| -rw-r--r-- | drivers/cpuidle/cpuidle-armada-370-xp.c | 4 | ||||
| -rw-r--r-- | include/acpi/processor.h | 10 | ||||
| -rw-r--r-- | include/linux/suspend.h | 2 | ||||
| -rw-r--r-- | kernel/power/hibernate.c | 37 | ||||
| -rw-r--r-- | kernel/power/main.c | 6 | ||||
| -rw-r--r-- | kernel/power/user.c | 3 |
17 files changed, 167 insertions, 60 deletions
diff --git a/Documentation/kernel-parameters.txt b/Documentation/kernel-parameters.txt index 6eaa9cdb7094..884904975d0b 100644 --- a/Documentation/kernel-parameters.txt +++ b/Documentation/kernel-parameters.txt @@ -1474,6 +1474,13 @@ bytes respectively. Such letter suffixes can also be entirely omitted. js= [HW,JOY] Analog joystick See Documentation/input/joystick.txt. + kaslr/nokaslr [X86] + Enable/disable kernel and module base offset ASLR + (Address Space Layout Randomization) if built into + the kernel. When CONFIG_HIBERNATION is selected, + kASLR is disabled by default. When kASLR is enabled, + hibernation will be disabled. + keepinitrd [HW,ARM] kernelcore=nn[KMG] [KNL,X86,IA-64,PPC] This parameter @@ -2110,10 +2117,6 @@ bytes respectively. Such letter suffixes can also be entirely omitted. noapic [SMP,APIC] Tells the kernel to not make use of any IOAPICs that may be present in the system. - nokaslr [X86] - Disable kernel and module base offset ASLR (Address - Space Layout Randomization) if built into the kernel. - noautogroup Disable scheduler automatic task group creation. nobats [PPC] Do not use BATs for mapping kernel lowmem @@ -2184,6 +2187,8 @@ bytes respectively. Such letter suffixes can also be entirely omitted. in certain environments such as networked servers or real-time systems. + nohibernate [HIBERNATION] Disable hibernation and resume. + nohz= [KNL] Boottime enable/disable dynamic ticks Valid arguments: on, off Default: on @@ -2980,6 +2985,7 @@ bytes respectively. Such letter suffixes can also be entirely omitted. noresume Don't check if there's a hibernation image present during boot. nocompress Don't compress/decompress hibernation images. + no Disable hibernation and resume. retain_initrd [RAM] Keep initrd memory after extraction diff --git a/arch/ia64/hp/common/sba_iommu.c b/arch/ia64/hp/common/sba_iommu.c index 1a871b78e570..344387a55406 100644 --- a/arch/ia64/hp/common/sba_iommu.c +++ b/arch/ia64/hp/common/sba_iommu.c @@ -242,7 +242,7 @@ struct ioc { struct pci_dev *sac_only_dev; }; -static struct ioc *ioc_list; +static struct ioc *ioc_list, *ioc_found; static int reserve_sba_gart = 1; static SBA_INLINE void sba_mark_invalid(struct ioc *, dma_addr_t, size_t); @@ -1809,20 +1809,13 @@ static struct ioc_iommu ioc_iommu_info[] __initdata = { { SX2000_IOC_ID, "sx2000", NULL }, }; -static struct ioc * -ioc_init(unsigned long hpa, void *handle) +static void ioc_init(unsigned long hpa, struct ioc *ioc) { - struct ioc *ioc; struct ioc_iommu *info; - ioc = kzalloc(sizeof(*ioc), GFP_KERNEL); - if (!ioc) - return NULL; - ioc->next = ioc_list; ioc_list = ioc; - ioc->handle = handle; ioc->ioc_hpa = ioremap(hpa, 0x1000); ioc->func_id = READ_REG(ioc->ioc_hpa + IOC_FUNC_ID); @@ -1863,8 +1856,6 @@ ioc_init(unsigned long hpa, void *handle) "%s %d.%d HPA 0x%lx IOVA space %dMb at 0x%lx\n", ioc->name, (ioc->rev >> 4) & 0xF, ioc->rev & 0xF, hpa, ioc->iov_size >> 20, ioc->ibase); - - return ioc; } @@ -2031,22 +2022,21 @@ sba_map_ioc_to_node(struct ioc *ioc, acpi_handle handle) #endif } -static int -acpi_sba_ioc_add(struct acpi_device *device, - const struct acpi_device_id *not_used) +static void acpi_sba_ioc_add(struct ioc *ioc) { - struct ioc *ioc; + acpi_handle handle = ioc->handle; acpi_status status; u64 hpa, length; struct acpi_device_info *adi; - status = hp_acpi_csr_space(device->handle, &hpa, &length); + ioc_found = ioc->next; + status = hp_acpi_csr_space(handle, &hpa, &length); if (ACPI_FAILURE(status)) - return 1; + goto err; - status = acpi_get_object_info(device->handle, &adi); + status = acpi_get_object_info(handle, &adi); if (ACPI_FAILURE(status)) - return 1; + goto err; /* * For HWP0001, only SBA appears in ACPI namespace. It encloses the PCI @@ -2067,13 +2057,13 @@ acpi_sba_ioc_add(struct acpi_device *device, if (!iovp_shift) iovp_shift = 12; - ioc = ioc_init(hpa, device->handle); - if (!ioc) - return 1; - + ioc_init(hpa, ioc); /* setup NUMA node association */ - sba_map_ioc_to_node(ioc, device->handle); - return 0; + sba_map_ioc_to_node(ioc, handle); + return; + + err: + kfree(ioc); } static const struct acpi_device_id hp_ioc_iommu_device_ids[] = { @@ -2081,9 +2071,26 @@ static const struct acpi_device_id hp_ioc_iommu_device_ids[] = { {"HWP0004", 0}, {"", 0}, }; + +static int acpi_sba_ioc_attach(struct acpi_device *device, + const struct acpi_device_id *not_used) +{ + struct ioc *ioc; + + ioc = kzalloc(sizeof(*ioc), GFP_KERNEL); + if (!ioc) + return -ENOMEM; + + ioc->next = ioc_found; + ioc_found = ioc; + ioc->handle = device->handle; + return 1; +} + + static struct acpi_scan_handler acpi_sba_ioc_handler = { .ids = hp_ioc_iommu_device_ids, - .attach = acpi_sba_ioc_add, + .attach = acpi_sba_ioc_attach, }; static int __init acpi_sba_ioc_init_acpi(void) @@ -2118,9 +2125,12 @@ sba_init(void) #endif /* - * ioc_list should be populated by the acpi_sba_ioc_handler's .attach() + * ioc_found should be populated by the acpi_sba_ioc_handler's .attach() * routine, but that only happens if acpi_scan_init() has already run. */ + while (ioc_found) + acpi_sba_ioc_add(ioc_found); + if (!ioc_list) { #ifdef CONFIG_IA64_GENERIC /* diff --git a/arch/x86/Kconfig b/arch/x86/Kconfig index fcefdda5136d..a8f749ef0fdc 100644 --- a/arch/x86/Kconfig +++ b/arch/x86/Kconfig @@ -1672,7 +1672,6 @@ config RELOCATABLE config RANDOMIZE_BASE bool "Randomize the address of the kernel image" depends on RELOCATABLE - depends on !HIBERNATION default n ---help--- Randomizes the physical and virtual address at which the diff --git a/arch/x86/boot/compressed/aslr.c b/arch/x86/boot/compressed/aslr.c index 4dbf967da50d..fc6091abedb7 100644 --- a/arch/x86/boot/compressed/aslr.c +++ b/arch/x86/boot/compressed/aslr.c @@ -289,10 +289,17 @@ unsigned char *choose_kernel_location(unsigned char *input, unsigned long choice = (unsigned long)output; unsigned long random; +#ifdef CONFIG_HIBERNATION + if (!cmdline_find_option_bool("kaslr")) { + debug_putstr("KASLR disabled by default...\n"); + goto out; + } +#else if (cmdline_find_option_bool("nokaslr")) { - debug_putstr("KASLR disabled...\n"); + debug_putstr("KASLR disabled by cmdline...\n"); goto out; } +#endif /* Record the various known unsafe memory ranges. */ mem_avoid_init((unsigned long)input, input_size, diff --git a/drivers/acpi/acpi_lpss.c b/drivers/acpi/acpi_lpss.c index 63407d264885..9cb65b0e7597 100644 --- a/drivers/acpi/acpi_lpss.c +++ b/drivers/acpi/acpi_lpss.c @@ -34,6 +34,9 @@ ACPI_MODULE_NAME("acpi_lpss"); /* Offsets relative to LPSS_PRIVATE_OFFSET */ #define LPSS_CLK_DIVIDER_DEF_MASK (BIT(1) | BIT(16)) +#define LPSS_RESETS 0x04 +#define LPSS_RESETS_RESET_FUNC BIT(0) +#define LPSS_RESETS_RESET_APB BIT(1) #define LPSS_GENERAL 0x08 #define LPSS_GENERAL_LTR_MODE_SW BIT(2) #define LPSS_GENERAL_UART_RTS_OVRD BIT(3) @@ -99,6 +102,17 @@ static void lpss_uart_setup(struct lpss_private_data *pdata) writel(reg | LPSS_GENERAL_UART_RTS_OVRD, pdata->mmio_base + offset); } +static void lpss_i2c_setup(struct lpss_private_data *pdata) +{ + unsigned int offset; + u32 val; + + offset = pdata->dev_desc->prv_offset + LPSS_RESETS; + val = readl(pdata->mmio_base + offset); + val |= LPSS_RESETS_RESET_APB | LPSS_RESETS_RESET_FUNC; + writel(val, pdata->mmio_base + offset); +} + static struct lpss_device_desc lpt_dev_desc = { .clk_required = true, .prv_offset = 0x800, @@ -171,6 +185,7 @@ static struct lpss_device_desc byt_i2c_dev_desc = { .prv_offset = 0x800, .save_ctx = true, .shared_clock = &i2c_clock, + .setup = lpss_i2c_setup, }; #else diff --git a/drivers/acpi/battery.c b/drivers/acpi/battery.c index e48fc98e71c4..0d7116f34b95 100644 --- a/drivers/acpi/battery.c +++ b/drivers/acpi/battery.c @@ -32,6 +32,7 @@ #include <linux/jiffies.h> #include <linux/async.h> #include <linux/dmi.h> +#include <linux/delay.h> #include <linux/slab.h> #include <linux/suspend.h> #include <asm/unaligned.h> @@ -70,6 +71,7 @@ MODULE_DESCRIPTION("ACPI Battery Driver"); MODULE_LICENSE("GPL"); static int battery_bix_broken_package; +static int battery_notification_delay_ms; static unsigned int cache_time = 1000; module_param(cache_time, uint, 0644); MODULE_PARM_DESC(cache_time, "cache time in milliseconds"); @@ -930,7 +932,10 @@ static ssize_t acpi_battery_write_alarm(struct file *file, goto end; } alarm_string[count] = '\0'; - battery->alarm = simple_strtol(alarm_string, NULL, 0); + if (kstrtoint(alarm_string, 0, &battery->alarm)) { + result = -EINVAL; + goto end; + } result = acpi_battery_set_alarm(battery); end: if (!result) @@ -1062,6 +1067,14 @@ static void acpi_battery_notify(struct acpi_device *device, u32 event) if (!battery) return; old = battery->bat.dev; + /* + * On Acer Aspire V5-573G notifications are sometimes triggered too + * early. For example, when AC is unplugged and notification is + * triggered, battery state is still reported as "Full", and changes to + * "Discharging" only after short delay, without any notification. + */ + if (battery_notification_delay_ms > 0) + msleep(battery_notification_delay_ms); if (event == ACPI_BATTERY_NOTIFY_INFO) acpi_battery_refresh(battery); acpi_battery_update(battery, false); @@ -1106,14 +1119,35 @@ static int battery_notify(struct notifier_block *nb, return 0; } +static int battery_bix_broken_package_quirk(const struct dmi_system_id *d) +{ + battery_bix_broken_package = 1; + return 0; +} + +static int battery_notification_delay_quirk(const struct dmi_system_id *d) +{ + battery_notification_delay_ms = 1000; + return 0; +} + static struct dmi_system_id bat_dmi_table[] = { { + .callback = battery_bix_broken_package_quirk, .ident = "NEC LZ750/LS", .matches = { DMI_MATCH(DMI_SYS_VENDOR, "NEC"), DMI_MATCH(DMI_PRODUCT_NAME, "PC-LZ750LS"), }, }, + { + .callback = battery_notification_delay_quirk, + .ident = "Acer Aspire V5-573G", + .matches = { + DMI_MATCH(DMI_SYS_VENDOR, "Acer"), + DMI_MATCH(DMI_PRODUCT_NAME, "Aspire V5-573G"), + }, + }, {}, }; @@ -1227,8 +1261,7 @@ static void __init acpi_battery_init_async(void *unused, async_cookie_t cookie) if (acpi_disabled) return; - if (dmi_check_system(bat_dmi_table)) - battery_bix_broken_package = 1; + dmi_check_system(bat_dmi_table); #ifdef CONFIG_ACPI_PROCFS_POWER acpi_battery_dir = acpi_lock_battery_dir(); diff --git a/drivers/acpi/osl.c b/drivers/acpi/osl.c index 3f2bdc812d23..bad25b070fe0 100644 --- a/drivers/acpi/osl.c +++ b/drivers/acpi/osl.c @@ -235,7 +235,8 @@ void acpi_os_vprintf(const char *fmt, va_list args) static unsigned long acpi_rsdp; static int __init setup_acpi_rsdp(char *arg) { - acpi_rsdp = simple_strtoul(arg, NULL, 16); + if (kstrtoul(arg, 16, &acpi_rsdp)) + return -EINVAL; return 0; } early_param("acpi_rsdp", setup_acpi_rsdp); diff --git a/drivers/acpi/tables.c b/drivers/acpi/tables.c index 05550ba44d32..6d5a6cda0734 100644 --- a/drivers/acpi/tables.c +++ b/drivers/acpi/tables.c @@ -360,7 +360,8 @@ static int __init acpi_parse_apic_instance(char *str) if (!str) return -EINVAL; - acpi_apic_instance = simple_strtoul(str, NULL, 0); + if (kstrtoint(str, 0, &acpi_apic_instance)) + return -EINVAL; pr_notice("Shall use APIC/MADT table %d\n", acpi_apic_instance); diff --git a/drivers/cpufreq/Kconfig b/drivers/cpufreq/Kconfig index e473d6555f96..ffe350f86bca 100644 --- a/drivers/cpufreq/Kconfig +++ b/drivers/cpufreq/Kconfig @@ -186,6 +186,8 @@ config CPU_FREQ_GOV_CONSERVATIVE config GENERIC_CPUFREQ_CPU0 tristate "Generic CPU0 cpufreq driver" depends on HAVE_CLK && OF + # if CPU_THERMAL is on and THERMAL=m, CPU0 cannot be =y: + depends on !CPU_THERMAL || THERMAL select PM_OPP help This adds a generic cpufreq driver for CPU0 frequency management. diff --git a/drivers/cpufreq/cpufreq.c b/drivers/cpufreq/cpufreq.c index aed2b0cb83dc..62259d27f03e 100644 --- a/drivers/cpufreq/cpufreq.c +++ b/drivers/cpufreq/cpufreq.c @@ -2242,10 +2242,8 @@ int cpufreq_update_policy(unsigned int cpu) struct cpufreq_policy new_policy; int ret; - if (!policy) { - ret = -ENODEV; - goto no_policy; - } + if (!policy) + return -ENODEV; down_write(&policy->rwsem); @@ -2264,7 +2262,7 @@ int cpufreq_update_policy(unsigned int cpu) new_policy.cur = cpufreq_driver->get(cpu); if (WARN_ON(!new_policy.cur)) { ret = -EIO; - goto no_policy; + goto unlock; } if (!policy->cur) { @@ -2279,10 +2277,10 @@ int cpufreq_update_policy(unsigned int cpu) ret = cpufreq_set_policy(policy, &new_policy); +unlock: up_write(&policy->rwsem); cpufreq_cpu_put(policy); -no_policy: return ret; } EXPORT_SYMBOL(cpufreq_update_policy); diff --git a/drivers/cpufreq/intel_pstate.c b/drivers/cpufreq/intel_pstate.c index 4e7f492ad583..924bb2d42b1c 100644 --- a/drivers/cpufreq/intel_pstate.c +++ b/drivers/cpufreq/intel_pstate.c @@ -196,10 +196,7 @@ static signed int pid_calc(struct _pid *pid, int32_t busy) pid->last_err = fp_error; result = pterm + mul_fp(pid->integral, pid->i_gain) + dterm; - if (result >= 0) - result = result + (1 << (FRAC_BITS-1)); - else - result = result - (1 << (FRAC_BITS-1)); + result = result + (1 << (FRAC_BITS-1)); return (signed int)fp_toint(result); } diff --git a/drivers/cpuidle/cpuidle-armada-370-xp.c b/drivers/cpuidle/cpuidle-armada-370-xp.c index 28587d0f3947..a5fba0287bfb 100644 --- a/drivers/cpuidle/cpuidle-armada-370-xp.c +++ b/drivers/cpuidle/cpuidle-armada-370-xp.c @@ -55,7 +55,7 @@ static struct cpuidle_driver armada_370_xp_idle_driver = { .power_usage = 50, .target_residency = 100, .flags = CPUIDLE_FLAG_TIME_VALID, - .name = "MV CPU IDLE", + .name = "Idle", .desc = "CPU power down", }, .states[2] = { @@ -65,7 +65,7 @@ static struct cpuidle_driver armada_370_xp_idle_driver = { .target_residency = 1000, .flags = CPUIDLE_FLAG_TIME_VALID | ARMADA_370_XP_FLAG_DEEP_IDLE, - .name = "MV CPU DEEP IDLE", + .name = "Deep idle", .desc = "CPU and L2 Fabric power down", }, .state_count = ARMADA_370_XP_MAX_STATES, diff --git a/include/acpi/processor.h b/include/acpi/processor.h index 6eb1d3cb5104..9b9b6f29bbf3 100644 --- a/include/acpi/processor.h +++ b/include/acpi/processor.h @@ -53,7 +53,7 @@ struct acpi_power_register { u8 bit_offset; u8 access_size; u64 address; -} __attribute__ ((packed)); +} __packed; struct acpi_processor_cx { u8 valid; @@ -83,7 +83,7 @@ struct acpi_psd_package { u64 domain; u64 coord_type; u64 num_processors; -} __attribute__ ((packed)); +} __packed; struct acpi_pct_register { u8 descriptor; @@ -93,7 +93,7 @@ struct acpi_pct_register { u8 bit_offset; u8 reserved; u64 address; -} __attribute__ ((packed)); +} __packed; struct acpi_processor_px { u64 core_frequency; /* megahertz */ @@ -124,7 +124,7 @@ struct acpi_tsd_package { u64 domain; u64 coord_type; u64 num_processors; -} __attribute__ ((packed)); +} __packed; struct acpi_ptc_register { u8 descriptor; @@ -134,7 +134,7 @@ struct acpi_ptc_register { u8 bit_offset; u8 reserved; u64 address; -} __attribute__ ((packed)); +} __packed; struct acpi_processor_tx_tss { u64 freqpercentage; /* */ diff --git a/include/linux/suspend.h b/include/linux/suspend.h index f76994b9396c..519064e0c943 100644 --- a/include/linux/suspend.h +++ b/include/linux/suspend.h @@ -327,6 +327,7 @@ extern unsigned long get_safe_page(gfp_t gfp_mask); extern void hibernation_set_ops(const struct platform_hibernation_ops *ops); extern int hibernate(void); extern bool system_entering_hibernation(void); +extern bool hibernation_available(void); asmlinkage int swsusp_save(void); extern struct pbe *restore_pblist; #else /* CONFIG_HIBERNATION */ @@ -339,6 +340,7 @@ static inline void swsusp_unset_page_free(struct page *p) {} static inline void hibernation_set_ops(const struct platform_hibernation_ops *ops) {} static inline int hibernate(void) { return -ENOSYS; } static inline bool system_entering_hibernation(void) { return false; } +static inline bool hibernation_available(void) { return false; } #endif /* CONFIG_HIBERNATION */ /* Hibernation and suspend events */ diff --git a/kernel/power/hibernate.c b/kernel/power/hibernate.c index 49e0a20fd010..fcc2611d3f14 100644 --- a/kernel/power/hibernate.c +++ b/kernel/power/hibernate.c @@ -35,6 +35,7 @@ static int nocompress; static int noresume; +static int nohibernate; static int resume_wait; static unsigned int resume_delay; static char resume_file[256] = CONFIG_PM_STD_PARTITION; @@ -62,6 +63,11 @@ bool freezer_test_done; static const struct platform_hibernation_ops *hibernation_ops; +bool hibernation_available(void) +{ + return (nohibernate == 0); +} + /** * hibernation_set_ops - Set the global hibernate operations. * @ops: Hibernation operations to use in subsequent hibernation transitions. @@ -642,6 +648,11 @@ int hibernate(void) { int error; + if (!hibernation_available()) { + pr_debug("PM: Hibernation not available.\n"); + return -EPERM; + } + lock_system_sleep(); /* The snapshot device should not be opened while we're running */ if (!atomic_add_unless(&snapshot_device_available, -1, 0)) { @@ -734,7 +745,7 @@ static int software_resume(void) /* * If the user said "noresume".. bail out early. */ - if (noresume) + if (noresume || !hibernation_available()) return 0; /* @@ -900,6 +911,9 @@ static ssize_t disk_show(struct kobject *kobj, struct kobj_attribute *attr, int i; char *start = buf; + if (!hibernation_available()) + return sprintf(buf, "[disabled]\n"); + for (i = HIBERNATION_FIRST; i <= HIBERNATION_MAX; i++) { if (!hibernation_modes[i]) continue; @@ -934,6 +948,9 @@ static ssize_t disk_store(struct kobject *kobj, struct kobj_attribute *attr, char *p; int mode = HIBERNATION_INVALID; + if (!hibernation_available()) + return -EPERM; + p = memchr(buf, '\n', n); len = p ? p - buf : n; @@ -1101,6 +1118,10 @@ static int __init hibernate_setup(char *str) noresume = 1; else if (!strncmp(str, "nocompress", 10)) nocompress = 1; + else if (!strncmp(str, "no", 2)) { + noresume = 1; + nohibernate = 1; + } return 1; } @@ -1125,9 +1146,23 @@ static int __init resumedelay_setup(char *str) return 1; } +static int __init nohibernate_setup(char *str) +{ + noresume = 1; + nohibernate = 1; + return 1; +} + +static int __init kaslr_nohibernate_setup(char *str) +{ + return nohibernate_setup(str); +} + __setup("noresume", noresume_setup); __setup("resume_offset=", resume_offset_setup); __setup("resume=", resume_setup); __setup("hibernate=", hibernate_setup); __setup("resumewait", resumewait_setup); __setup("resumedelay=", resumedelay_setup); +__setup("nohibernate", nohibernate_setup); +__setup("kaslr", kaslr_nohibernate_setup); diff --git a/kernel/power/main.c b/kernel/power/main.c index 573410d6647e..8e90f330f139 100644 --- a/kernel/power/main.c +++ b/kernel/power/main.c @@ -300,13 +300,11 @@ static ssize_t state_show(struct kobject *kobj, struct kobj_attribute *attr, s += sprintf(s,"%s ", pm_states[i].label); #endif -#ifdef CONFIG_HIBERNATION - s += sprintf(s, "%s\n", "disk"); -#else + if (hibernation_available()) + s += sprintf(s, "disk "); if (s != buf) /* convert the last space to a newline */ *(s-1) = '\n'; -#endif return (s - buf); } diff --git a/kernel/power/user.c b/kernel/power/user.c index 98d357584cd6..526e8911460a 100644 --- a/kernel/power/user.c +++ b/kernel/power/user.c @@ -49,6 +49,9 @@ static int snapshot_open(struct inode *inode, struct file *filp) struct snapshot_data *data; int error; + if (!hibernation_available()) + return -EPERM; + lock_system_sleep(); if (!atomic_add_unless(&snapshot_device_available, -1, 0)) { |