Merge tag 'pm+acpi-3.16-rc2' of git://git.kernel.org/pub/scm/linux/kernel/git/rafael/linux-pm
Pull ACPI and power management fixes from Rafael Wysocki:
"These are fixes mostly (ia64 regression related to the ACPI
enumeration of devices, cpufreq regressions, fix for I2C controllers
included in Intel SoCs, mvebu cpuidle driver fix related to sysfs)
plus additional kernel command line arguments from Kees to make it
possible to build kernel images with hibernation and the kernel
address space randomization included simultaneously, a new ACPI
battery driver quirk for a system with a broken BIOS and a couple of
ACPI core cleanups.
Specifics:
- Fix for an ia64 regression introduced during the 3.11 cycle by a
commit that modified the hardware initialization ordering and made
device discovery fail on some systems.
- Fix for a build problem on systems where the cpufreq-cpu0 driver is
built-in and the cpu-thermal driver is modular from Arnd Bergmann.
- Fix for a recently introduced computational mistake in the
intel_pstate driver that leads to excessive rounding errors from
Doug Smythies.
- Fix for a failure code path in cpufreq_update_policy() that fails
to unlock the locks acquired previously from Aaron Plattner.
- Fix for the cpuidle mvebu driver to use shorter state names which
will prevent the sysfs interface from returning mangled strings.
From Gregory Clement.
- ACPI LPSS driver fix to make sure that the I2C controllers included
in BayTrail SoCs are not held in the reset state while they are
being probed from Mika Westerberg.
- New kernel command line arguments making it possible to build
kernel images with hibernation and kASLR included at the same time
and to select which of them will be used via the command line (they
are still functionally mutually exclusive, though). From Kees
Cook.
- ACPI battery driver quirk for Acer Aspire V5-573G that fails to
send battery status change notifications timely from Alexander
Mezin.
- Two ACPI core cleanups from Christoph Jaeger and Fabian Frederick"
* tag 'pm+acpi-3.16-rc2' of git://git.kernel.org/pub/scm/linux/kernel/git/rafael/linux-pm:
cpuidle: mvebu: Fix the name of the states
cpufreq: unlock when failing cpufreq_update_policy()
intel_pstate: Correct rounding in busy calculation
ACPI: use kstrto*() instead of simple_strto*()
ACPI / processor replace __attribute__((packed)) by __packed
ACPI / battery: add quirk for Acer Aspire V5-573G
ACPI / battery: use callback for setting up quirks
ACPI / LPSS: Take I2C host controllers out of reset
x86, kaslr: boot-time selectable with hibernation
PM / hibernate: introduce "nohibernate" boot parameter
cpufreq: cpufreq-cpu0: fix CPU_THERMAL dependency
ACPI / ia64 / sba_iommu: Restore the working initialization ordering
diff --git a/Documentation/kernel-parameters.txt b/Documentation/kernel-parameters.txt
index 6eaa9cd..8849049 100644
--- a/Documentation/kernel-parameters.txt
+++ b/Documentation/kernel-parameters.txt
@@ -1474,6 +1474,13 @@
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 @@
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 @@
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 @@
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 1a871b7..344387a 100644
--- a/arch/ia64/hp/common/sba_iommu.c
+++ b/arch/ia64/hp/common/sba_iommu.c
@@ -242,7 +242,7 @@
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 @@
{ 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 @@
"%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 @@
#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 @@
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 @@
{"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 @@
#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 fcefdda..a8f749e 100644
--- a/arch/x86/Kconfig
+++ b/arch/x86/Kconfig
@@ -1672,7 +1672,6 @@
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 4dbf967..fc6091a 100644
--- a/arch/x86/boot/compressed/aslr.c
+++ b/arch/x86/boot/compressed/aslr.c
@@ -289,10 +289,17 @@
unsigned long choice = (unsigned long)output;
unsigned long random;
- if (cmdline_find_option_bool("nokaslr")) {
- debug_putstr("KASLR disabled...\n");
+#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 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 63407d2..9cb65b0 100644
--- a/drivers/acpi/acpi_lpss.c
+++ b/drivers/acpi/acpi_lpss.c
@@ -34,6 +34,9 @@
/* 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 @@
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 @@
.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 e48fc98..0d7116f 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_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 @@
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 @@
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 @@
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 @@
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 3f2bdc8..bad25b0 100644
--- a/drivers/acpi/osl.c
+++ b/drivers/acpi/osl.c
@@ -235,7 +235,8 @@
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 05550ba..6d5a6cd 100644
--- a/drivers/acpi/tables.c
+++ b/drivers/acpi/tables.c
@@ -360,7 +360,8 @@
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 e473d65..ffe350f 100644
--- a/drivers/cpufreq/Kconfig
+++ b/drivers/cpufreq/Kconfig
@@ -186,6 +186,8 @@
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 aed2b0c..62259d2 100644
--- a/drivers/cpufreq/cpufreq.c
+++ b/drivers/cpufreq/cpufreq.c
@@ -2242,10 +2242,8 @@
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 @@
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 @@
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 4e7f492..924bb2d 100644
--- a/drivers/cpufreq/intel_pstate.c
+++ b/drivers/cpufreq/intel_pstate.c
@@ -196,10 +196,7 @@
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 28587d0..a5fba02 100644
--- a/drivers/cpuidle/cpuidle-armada-370-xp.c
+++ b/drivers/cpuidle/cpuidle-armada-370-xp.c
@@ -55,7 +55,7 @@
.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 @@
.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 6eb1d3c..9b9b6f2 100644
--- a/include/acpi/processor.h
+++ b/include/acpi/processor.h
@@ -53,7 +53,7 @@
u8 bit_offset;
u8 access_size;
u64 address;
-} __attribute__ ((packed));
+} __packed;
struct acpi_processor_cx {
u8 valid;
@@ -83,7 +83,7 @@
u64 domain;
u64 coord_type;
u64 num_processors;
-} __attribute__ ((packed));
+} __packed;
struct acpi_pct_register {
u8 descriptor;
@@ -93,7 +93,7 @@
u8 bit_offset;
u8 reserved;
u64 address;
-} __attribute__ ((packed));
+} __packed;
struct acpi_processor_px {
u64 core_frequency; /* megahertz */
@@ -124,7 +124,7 @@
u64 domain;
u64 coord_type;
u64 num_processors;
-} __attribute__ ((packed));
+} __packed;
struct acpi_ptc_register {
u8 descriptor;
@@ -134,7 +134,7 @@
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 f76994b..519064e 100644
--- a/include/linux/suspend.h
+++ b/include/linux/suspend.h
@@ -327,6 +327,7 @@
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 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 49e0a20..fcc2611 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 @@
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 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 @@
/*
* If the user said "noresume".. bail out early.
*/
- if (noresume)
+ if (noresume || !hibernation_available())
return 0;
/*
@@ -900,6 +911,9 @@
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 @@
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 @@
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 @@
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 573410d..8e90f33 100644
--- a/kernel/power/main.c
+++ b/kernel/power/main.c
@@ -300,13 +300,11 @@
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 98d3575..526e891 100644
--- a/kernel/power/user.c
+++ b/kernel/power/user.c
@@ -49,6 +49,9 @@
struct snapshot_data *data;
int error;
+ if (!hibernation_available())
+ return -EPERM;
+
lock_system_sleep();
if (!atomic_add_unless(&snapshot_device_available, -1, 0)) {
