acpi= [HW,ACPI,X86,ARM64,RISCV64,EARLY]
Advanced Configuration and Power Interface
Format: { force | on | off | strict | noirq | rsdt |
- copy_dsdt }
+ copy_dsdt | nospcr }
force -- enable ACPI if default was off
on -- enable ACPI but allow fallback to DT [arm64,riscv64]
off -- disable ACPI if default was on
strictly ACPI specification compliant.
rsdt -- prefer RSDT over (default) XSDT
copy_dsdt -- copy DSDT to memory
- For ARM64 and RISCV64, ONLY "acpi=off", "acpi=on" or
- "acpi=force" are available
+ nospcr -- disable console in ACPI SPCR table as
+ default _serial_ console on ARM64
+ For ARM64, ONLY "acpi=off", "acpi=on", "acpi=force" or
+ "acpi=nospcr" are available
+ For RISCV64, ONLY "acpi=off", "acpi=on" or "acpi=force"
+ are available
See also Documentation/power/runtime_pm.rst, pci=noacpi
Documentation/networking/netconsole.rst for an
alternative.
- <DEVNAME>:<n>.<n>[,options]
- Use the specified serial port on the serial core bus.
- The addressing uses DEVNAME of the physical serial port
- device, followed by the serial core controller instance,
- and the serial port instance. The options are the same
- as documented for the ttyS addressing above.
-
- The mapping of the serial ports to the tty instances
- can be viewed with:
-
- $ ls -d /sys/bus/serial-base/devices/*:*.*/tty/*
- /sys/bus/serial-base/devices/00:04:0.0/tty/ttyS0
-
- In the above example, the console can be addressed with
- console=00:04:0.0. Note that a console addressed this
- way will only get added when the related device driver
- is ready. The use of an earlycon parameter in addition to
- the console may be desired for console output early on.
-
uart[8250],io,<addr>[,options]
uart[8250],mmio,<addr>[,options]
uart[8250],mmio16,<addr>[,options]
Format: 0 | 1
Default set by CONFIG_INIT_ON_FREE_DEFAULT_ON.
- init_mlocked_on_free= [MM] Fill freed userspace memory with zeroes if
- it was mlock'ed and not explicitly munlock'ed
- afterwards.
- Format: 0 | 1
- Default set by CONFIG_INIT_MLOCKED_ON_FREE_DEFAULT_ON
-
init_pkru= [X86] Specify the default memory protection keys rights
register contents for all processes. 0x55555554 by
default (disallow access to all but pkey 0). Can
the ->nocb_bypass queue. The definition of "too
many" is supplied by this kernel boot parameter.
+ rcutree.nohz_full_patience_delay= [KNL]
+ On callback-offloaded (rcu_nocbs) CPUs, avoid
+ disturbing RCU unless the grace period has
+ reached the specified age in milliseconds.
+ Defaults to zero. Large values will be capped
+ at five seconds. All values will be rounded down
+ to the nearest value representable by jiffies.
+
rcutree.qhimark= [KNL]
Set threshold of queued RCU callbacks beyond which
batch limiting is disabled.
select ACPI_CCA_REQUIRED if ACPI
select ACPI_GENERIC_GSI if ACPI
select ACPI_GTDT if ACPI
+ select ACPI_HOTPLUG_CPU if ACPI_PROCESSOR && HOTPLUG_CPU
select ACPI_IORT if ACPI
select ACPI_REDUCED_HARDWARE_ONLY if ACPI
select ACPI_MCFG if (ACPI && PCI)
config BUILTIN_RETURN_ADDRESS_STRIPS_PAC
bool
- # Clang's __builtin_return_adddress() strips the PAC since 12.0.0
+ # Clang's __builtin_return_address() strips the PAC since 12.0.0
# https://github.com/llvm/llvm-project/commit/2a96f47c5ffca84cd774ad402cacd137f4bf45e2
default y if CC_IS_CLANG
# GCC's __builtin_return_address() strips the PAC since 11.1.0,
If unsure, say Y.
- config ARM64_WORKAROUND_SPECULATIVE_SSBS
- bool
-
config ARM64_ERRATUM_3194386
- bool "Cortex-X4: 3194386: workaround for MSR SSBS not self-synchronizing"
- select ARM64_WORKAROUND_SPECULATIVE_SSBS
- default y
- help
- This option adds the workaround for ARM Cortex-X4 erratum 3194386.
-
- On affected cores "MSR SSBS, #0" instructions may not affect
- subsequent speculative instructions, which may permit unexepected
- speculative store bypassing.
-
- Work around this problem by placing a speculation barrier after
- kernel changes to SSBS. The presence of the SSBS special-purpose
- register is hidden from hwcaps and EL0 reads of ID_AA64PFR1_EL1, such
- that userspace will use the PR_SPEC_STORE_BYPASS prctl to change
- SSBS.
-
- If unsure, say Y.
-
- config ARM64_ERRATUM_3312417
- bool "Neoverse-V3: 3312417: workaround for MSR SSBS not self-synchronizing"
- select ARM64_WORKAROUND_SPECULATIVE_SSBS
+ bool "Cortex-{A720,X4,X925}/Neoverse-V3: workaround for MSR SSBS not self-synchronizing"
default y
help
- This option adds the workaround for ARM Neoverse-V3 erratum 3312417.
+ This option adds the workaround for the following errata:
+
+ * ARM Cortex-A710 erratam 3324338
+ * ARM Cortex-A720 erratum 3456091
+ * ARM Cortex-X2 erratum 3324338
+ * ARM Cortex-X3 erratum 3324335
+ * ARM Cortex-X4 erratum 3194386
+ * ARM Cortex-X925 erratum 3324334
+ * ARM Neoverse N2 erratum 3324339
+ * ARM Neoverse V2 erratum 3324336
+ * ARM Neoverse-V3 erratum 3312417
On affected cores "MSR SSBS, #0" instructions may not affect
subsequent speculative instructions, which may permit unexepected
If unsure, say Y.
-
config CAVIUM_ERRATUM_22375
bool "Cavium erratum 22375, 24313"
default y
config ARM64_SW_TTBR0_PAN
bool "Emulate Privileged Access Never using TTBR0_EL1 switching"
+ depends on !KCSAN
help
Enabling this option prevents the kernel from accessing
user-space memory directly by pointing TTBR0_EL1 to a reserved
void __init bringup_nonboot_cpus(unsigned int max_cpus)
{
+ if (!max_cpus)
+ return;
+
/* Try parallel bringup optimization if enabled */
if (cpuhp_bringup_cpus_parallel(max_cpus))
return;
cpumask_clear(frozen_cpus);
pr_info("Disabling non-boot CPUs ...\n");
- for_each_online_cpu(cpu) {
- if (cpu == primary)
+ for (cpu = nr_cpu_ids - 1; cpu >= 0; cpu--) {
+ if (!cpu_online(cpu) || cpu == primary)
continue;
if (pm_wakeup_pending()) {
* The caller needs to hold cpus read locked while calling this function.
* Return:
* On success:
- * Positive state number if @state is CPUHP_AP_ONLINE_DYN;
+ * Positive state number if @state is CPUHP_AP_ONLINE_DYN or CPUHP_BP_PREPARE_DYN;
* 0 for all other states
* On failure: proper (negative) error code
*/
ret = cpuhp_store_callbacks(state, name, startup, teardown,
multi_instance);
- dynstate = state == CPUHP_AP_ONLINE_DYN;
+ dynstate = state == CPUHP_AP_ONLINE_DYN || state == CPUHP_BP_PREPARE_DYN;
if (ret > 0 && dynstate) {
state = ret;
ret = 0;
out:
mutex_unlock(&cpuhp_state_mutex);
/*
- * If the requested state is CPUHP_AP_ONLINE_DYN, return the
- * dynamically allocated state in case of success.
+ * If the requested state is CPUHP_AP_ONLINE_DYN or CPUHP_BP_PREPARE_DYN,
+ * return the dynamically allocated state in case of success.
*/
if (!ret && dynstate)
return state;
struct cpumask __cpu_online_mask __read_mostly;
EXPORT_SYMBOL(__cpu_online_mask);
+ struct cpumask __cpu_enabled_mask __read_mostly;
+ EXPORT_SYMBOL(__cpu_enabled_mask);
+
struct cpumask __cpu_present_mask __read_mostly;
EXPORT_SYMBOL(__cpu_present_mask);