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Merge android-4.4-p.202 (a4d443b7) into msm-4.4
[sagit-ice-cold/kernel_xiaomi_msm8998.git] / Documentation / kernel-parameters.txt
index cb582b2..d170c8f 100644 (file)
@@ -549,6 +549,10 @@ bytes respectively. Such letter suffixes can also be entirely omitted.
                        embedded devices based on command line input.
                        See Documentation/block/cmdline-partition.txt
 
+       boot_cpus=      [SMP]
+                       Rather than attempting to online all possible CPUs at
+                       boot time, only online the specified set of CPUs.
+
        boot_delay=     Milliseconds to delay each printk during boot.
                        Values larger than 10 seconds (10000) are changed to
                        no delay (0).
@@ -746,6 +750,12 @@ bytes respectively. Such letter suffixes can also be entirely omitted.
                        seconds. Defaults to 10*60 = 10mins. A value of 0
                        disables the blank timer.
 
+       core_ctl_disable_cpumask= [SMP]
+                       Exempt the CPUs from being managed by core_ctl.
+                       core_ctl operates on a cluster basis. So all the
+                       CPUs in a given cluster must be specified to disable
+                       core_ctl for that cluster.
+
        coredump_filter=
                        [KNL] Change the default value for
                        /proc/<pid>/coredump_filter.
@@ -938,7 +948,7 @@ bytes respectively. Such letter suffixes can also be entirely omitted.
                        The filter can be disabled or changed to another
                        driver later using sysfs.
 
-       drm_kms_helper.edid_firmware=[<connector>:]<file>[,[<connector>:]<file>]
+       drm.edid_firmware=[<connector>:]<file>[,[<connector>:]<file>]
                        Broken monitors, graphic adapters, KVMs and EDIDless
                        panels may send no or incorrect EDID data sets.
                        This parameter allows to specify an EDID data sets
@@ -2230,6 +2240,7 @@ bytes respectively. Such letter suffixes can also be entirely omitted.
                                               spectre_v2_user=off [X86]
                                               spec_store_bypass_disable=off [X86]
                                               mds=off [X86]
+                                              tsx_async_abort=off [X86]
 
                        auto (default)
                                Mitigate all CPU vulnerabilities, but leave SMT
@@ -2797,6 +2808,11 @@ bytes respectively. Such letter suffixes can also be entirely omitted.
                        we can turn it on.
                        on: enable the feature
 
+       page_poison=    [KNL] Boot-time parameter changing the state of
+                       poisoning on the buddy allocator.
+                       off: turn off poisoning
+                       on: turn on poisoning
+
        panic=          [KNL] Kernel behaviour on panic: delay <timeout>
                        timeout > 0: seconds before rebooting
                        timeout = 0: wait forever
@@ -4116,6 +4132,67 @@ bytes respectively. Such letter suffixes can also be entirely omitted.
                        platforms where RDTSC is slow and this accounting
                        can add overhead.
 
+       tsx=            [X86] Control Transactional Synchronization
+                       Extensions (TSX) feature in Intel processors that
+                       support TSX control.
+
+                       This parameter controls the TSX feature. The options are:
+
+                       on      - Enable TSX on the system. Although there are
+                               mitigations for all known security vulnerabilities,
+                               TSX has been known to be an accelerator for
+                               several previous speculation-related CVEs, and
+                               so there may be unknown security risks associated
+                               with leaving it enabled.
+
+                       off     - Disable TSX on the system. (Note that this
+                               option takes effect only on newer CPUs which are
+                               not vulnerable to MDS, i.e., have
+                               MSR_IA32_ARCH_CAPABILITIES.MDS_NO=1 and which get
+                               the new IA32_TSX_CTRL MSR through a microcode
+                               update. This new MSR allows for the reliable
+                               deactivation of the TSX functionality.)
+
+                       auto    - Disable TSX if X86_BUG_TAA is present,
+                                 otherwise enable TSX on the system.
+
+                       Not specifying this option is equivalent to tsx=off.
+
+                       See Documentation/hw-vuln/tsx_async_abort.rst
+                       for more details.
+
+       tsx_async_abort= [X86,INTEL] Control mitigation for the TSX Async
+                       Abort (TAA) vulnerability.
+
+                       Similar to Micro-architectural Data Sampling (MDS)
+                       certain CPUs that support Transactional
+                       Synchronization Extensions (TSX) are vulnerable to an
+                       exploit against CPU internal buffers which can forward
+                       information to a disclosure gadget under certain
+                       conditions.
+
+                       In vulnerable processors, the speculatively forwarded
+                       data can be used in a cache side channel attack, to
+                       access data to which the attacker does not have direct
+                       access.
+
+                       This parameter controls the TAA mitigation.  The
+                       options are:
+
+                       full       - Enable TAA mitigation on vulnerable CPUs
+                                    if TSX is enabled.
+
+                       off        - Unconditionally disable TAA mitigation
+
+                       Not specifying this option is equivalent to
+                       tsx_async_abort=full.  On CPUs which are MDS affected
+                       and deploy MDS mitigation, TAA mitigation is not
+                       required and doesn't provide any additional
+                       mitigation.
+
+                       For details see:
+                       Documentation/hw-vuln/tsx_async_abort.rst
+
        turbografx.map[2|3]=    [HW,JOY]
                        TurboGraFX parallel port interface
                        Format:
@@ -4398,6 +4475,15 @@ bytes respectively. Such letter suffixes can also be entirely omitted.
                        or other driver-specific files in the
                        Documentation/watchdog/ directory.
 
+       workqueue.watchdog_thresh=
+                       If CONFIG_WQ_WATCHDOG is configured, workqueue can
+                       warn stall conditions and dump internal state to
+                       help debugging.  0 disables workqueue stall
+                       detection; otherwise, it's the stall threshold
+                       duration in seconds.  The default value is 30 and
+                       it can be updated at runtime by writing to the
+                       corresponding sysfs file.
+
        workqueue.disable_numa
                        By default, all work items queued to unbound
                        workqueues are affine to the NUMA nodes they're