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path: root/drivers/base/cpu.c
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2023-04-05tick/nohz: Fix cpu_is_hotpluggable() by checking with nohz subsystemJoel Fernandes (Google)1-1/+2
For CONFIG_NO_HZ_FULL systems, the tick_do_timer_cpu cannot be offlined. However, cpu_is_hotpluggable() still returns true for those CPUs. This causes torture tests that do offlining to end up trying to offline this CPU causing test failures. Such failure happens on all architectures. Fix the repeated error messages thrown by this (even if the hotplug errors are harmless) by asking the opinion of the nohz subsystem on whether the CPU can be hotplugged. [ Apply Frederic Weisbecker feedback on refactoring tick_nohz_cpu_down(). ] For drivers/base/ portion: Acked-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org> Acked-by: Frederic Weisbecker <frederic@kernel.org> Cc: Frederic Weisbecker <frederic@kernel.org> Cc: "Paul E. McKenney" <paulmck@kernel.org> Cc: Zhouyi Zhou <zhouzhouyi@gmail.com> Cc: Will Deacon <will@kernel.org> Cc: Marc Zyngier <maz@kernel.org> Cc: rcu <rcu@vger.kernel.org> Cc: stable@vger.kernel.org Fixes: 2987557f52b9 ("driver-core/cpu: Expose hotpluggability to the rest of the kernel") Signed-off-by: Paul E. McKenney <paulmck@kernel.org> Signed-off-by: Joel Fernandes (Google) <joel@joelfernandes.org>
2023-02-11driver core: cpu: don't hand-override the uevent bus_type callback.Greg Kroah-Hartman1-14/+14
Instead of having to change the uevent bus_type callback by hand at runtime, set it at build time based on the build configuration options, making this much simpler to maintain and understand (and allow to make the structure constant.) Cc: "Rafael J. Wysocki" <rafael@kernel.org> Link: https://lore.kernel.org/r/20230210102408.1083177-1-gregkh@linuxfoundation.org Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2023-02-10driver core: bus: add bus_get_dev_root() functionGreg Kroah-Hartman1-3/+7
Instead of poking around in the struct bus_type directly for the dev_root pointer, provide a function to return it properly reference counted, if it is present in the bus. This will be needed to move the pointer out of struct bus_type in the future. Use the function in the driver core code at the same time it is introduced to verify that it works properly. Cc: "Rafael J. Wysocki" <rafael@kernel.org> Link: https://lore.kernel.org/r/20230209093556.19132-1-gregkh@linuxfoundation.org Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2023-01-27driver core: make struct bus_type.uevent() take a const *Greg Kroah-Hartman1-1/+1
The uevent() callback in struct bus_type should not be modifying the device that is passed into it, so mark it as a const * and propagate the function signature changes out into all relevant subsystems that use this callback. Acked-by: Rafael J. Wysocki <rafael@kernel.org> Acked-by: Hans de Goede <hdegoede@redhat.com> Link: https://lore.kernel.org/r/20230111113018.459199-16-gregkh@linuxfoundation.org Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2022-06-27x86/bugs: Report AMD retbleed vulnerabilityAlexandre Chartre1-0/+8
Report that AMD x86 CPUs are vulnerable to the RETBleed (Arbitrary Speculative Code Execution with Return Instructions) attack. [peterz: add hygon] [kim: invert parity; fam15h] Co-developed-by: Kim Phillips <kim.phillips@amd.com> Signed-off-by: Kim Phillips <kim.phillips@amd.com> Signed-off-by: Alexandre Chartre <alexandre.chartre@oracle.com> Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org> Signed-off-by: Borislav Petkov <bp@suse.de> Reviewed-by: Josh Poimboeuf <jpoimboe@kernel.org> Signed-off-by: Borislav Petkov <bp@suse.de>
2022-05-21x86/speculation/mmio: Add sysfs reporting for Processor MMIO Stale DataPawan Gupta1-0/+8
Add the sysfs reporting file for Processor MMIO Stale Data vulnerability. It exposes the vulnerability and mitigation state similar to the existing files for the other hardware vulnerabilities. Signed-off-by: Pawan Gupta <pawan.kumar.gupta@linux.intel.com> Signed-off-by: Borislav Petkov <bp@suse.de>
2022-02-16sched/isolation: Use single feature type while referring to housekeeping cpumaskFrederic Weisbecker1-1/+1
Refer to housekeeping APIs using single feature types instead of flags. This prevents from passing multiple isolation features at once to housekeeping interfaces, which soon won't be possible anymore as each isolation features will have their own cpumask. Signed-off-by: Frederic Weisbecker <frederic@kernel.org> Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org> Reviewed-by: Juri Lelli <juri.lelli@redhat.com> Reviewed-by: Phil Auld <pauld@redhat.com> Link: https://lore.kernel.org/r/20220207155910.527133-5-frederic@kernel.org
2021-07-21driver: base: Prefer unsigned int to bare use of unsignedJinchao Wang1-2/+2
Fix checkpatch warnings: WARNING: Prefer 'unsigned int' to bare use of 'unsigned' Signed-off-by: Jinchao Wang <wjc@cdjrlc.com> Link: https://lore.kernel.org/r/20210628171907.63646-2-wjc@cdjrlc.com Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2021-06-04drivers/base: Constify static attribute_group structsRikard Falkeborn1-2/+2
These are only used by putting their address in an array of pointers to const struct attribute_group (either directly or via the __ATTRIBUTE_GROUP macro). Make them const to allow the compiler to place them in read-only memory. Signed-off-by: Rikard Falkeborn <rikard.falkeborn@gmail.com> Link: https://lore.kernel.org/r/20210528213408.20067-1-rikard.falkeborn@gmail.com Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2021-03-23drivers/base/cpu: remove redundant assignment of variable retvalColin Ian King1-4/+2
The variable retval is being initialized with a value that is never read and it is being updated later with a new value. Clean this up by initializing retval to -ENOMEM and remove the assignment to retval on the !dev failure path. Kudos to Rafael for the improved fix suggestion. Reviewed-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com> Signed-off-by: Colin Ian King <colin.king@canonical.com> Link: https://lore.kernel.org/r/20210218202837.516231-1-colin.king@canonical.com Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2020-10-02drivers core: Miscellaneous changes for sysfs_emitJoe Perches1-32/+30
Change additional instances that could use sysfs_emit and sysfs_emit_at that the coccinelle script could not convert. o macros creating show functions with ## concatenation o unbound sprintf uses with buf+len for start of output to sysfs_emit_at o returns with ?: tests and sprintf to sysfs_emit o sysfs output with struct class * not struct device * arguments Miscellanea: o remove unnecessary initializations around these changes o consistently use int len for return length of show functions o use octal permissions and not S_<FOO> o rename a few show function names so DEVICE_ATTR_<FOO> can be used o use DEVICE_ATTR_ADMIN_RO where appropriate o consistently use const char *output for strings o checkpatch/style neatening Signed-off-by: Joe Perches <joe@perches.com> Link: https://lore.kernel.org/r/8bc24444fe2049a9b2de6127389b57edfdfe324d.1600285923.git.joe@perches.com Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2020-10-02drivers core: Use sysfs_emit and sysfs_emit_at for show(device *...) functionsJoe Perches1-16/+16
Convert the various sprintf fmaily calls in sysfs device show functions to sysfs_emit and sysfs_emit_at for PAGE_SIZE buffer safety. Done with: $ spatch -sp-file sysfs_emit_dev.cocci --in-place --max-width=80 . And cocci script: $ cat sysfs_emit_dev.cocci @@ identifier d_show; identifier dev, attr, buf; @@ ssize_t d_show(struct device *dev, struct device_attribute *attr, char *buf) { <... return - sprintf(buf, + sysfs_emit(buf, ...); ...> } @@ identifier d_show; identifier dev, attr, buf; @@ ssize_t d_show(struct device *dev, struct device_attribute *attr, char *buf) { <... return - snprintf(buf, PAGE_SIZE, + sysfs_emit(buf, ...); ...> } @@ identifier d_show; identifier dev, attr, buf; @@ ssize_t d_show(struct device *dev, struct device_attribute *attr, char *buf) { <... return - scnprintf(buf, PAGE_SIZE, + sysfs_emit(buf, ...); ...> } @@ identifier d_show; identifier dev, attr, buf; expression chr; @@ ssize_t d_show(struct device *dev, struct device_attribute *attr, char *buf) { <... return - strcpy(buf, chr); + sysfs_emit(buf, chr); ...> } @@ identifier d_show; identifier dev, attr, buf; identifier len; @@ ssize_t d_show(struct device *dev, struct device_attribute *attr, char *buf) { <... len = - sprintf(buf, + sysfs_emit(buf, ...); ...> return len; } @@ identifier d_show; identifier dev, attr, buf; identifier len; @@ ssize_t d_show(struct device *dev, struct device_attribute *attr, char *buf) { <... len = - snprintf(buf, PAGE_SIZE, + sysfs_emit(buf, ...); ...> return len; } @@ identifier d_show; identifier dev, attr, buf; identifier len; @@ ssize_t d_show(struct device *dev, struct device_attribute *attr, char *buf) { <... len = - scnprintf(buf, PAGE_SIZE, + sysfs_emit(buf, ...); ...> return len; } @@ identifier d_show; identifier dev, attr, buf; identifier len; @@ ssize_t d_show(struct device *dev, struct device_attribute *attr, char *buf) { <... - len += scnprintf(buf + len, PAGE_SIZE - len, + len += sysfs_emit_at(buf, len, ...); ...> return len; } @@ identifier d_show; identifier dev, attr, buf; expression chr; @@ ssize_t d_show(struct device *dev, struct device_attribute *attr, char *buf) { ... - strcpy(buf, chr); - return strlen(buf); + return sysfs_emit(buf, chr); } Signed-off-by: Joe Perches <joe@perches.com> Link: https://lore.kernel.org/r/3d033c33056d88bbe34d4ddb62afd05ee166ab9a.1600285923.git.joe@perches.com Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2020-04-20x86/speculation: Add Special Register Buffer Data Sampling (SRBDS) mitigationMark Gross1-0/+8
SRBDS is an MDS-like speculative side channel that can leak bits from the random number generator (RNG) across cores and threads. New microcode serializes the processor access during the execution of RDRAND and RDSEED. This ensures that the shared buffer is overwritten before it is released for reuse. While it is present on all affected CPU models, the microcode mitigation is not needed on models that enumerate ARCH_CAPABILITIES[MDS_NO] in the cases where TSX is not supported or has been disabled with TSX_CTRL. The mitigation is activated by default on affected processors and it increases latency for RDRAND and RDSEED instructions. Among other effects this will reduce throughput from /dev/urandom. * Enable administrator to configure the mitigation off when desired using either mitigations=off or srbds=off. * Export vulnerability status via sysfs * Rename file-scoped macros to apply for non-whitelist table initializations. [ bp: Massage, - s/VULNBL_INTEL_STEPPING/VULNBL_INTEL_STEPPINGS/g, - do not read arch cap MSR a second time in tsx_fused_off() - just pass it in, - flip check in cpu_set_bug_bits() to save an indentation level, - reflow comments. jpoimboe: s/Mitigated/Mitigation/ in user-visible strings tglx: Dropped the fused off magic for now ] Signed-off-by: Mark Gross <mgross@linux.intel.com> Signed-off-by: Borislav Petkov <bp@suse.de> Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Reviewed-by: Tony Luck <tony.luck@intel.com> Reviewed-by: Pawan Gupta <pawan.kumar.gupta@linux.intel.com> Reviewed-by: Josh Poimboeuf <jpoimboe@redhat.com> Tested-by: Neelima Krishnan <neelima.krishnan@intel.com>
2020-03-31Merge tag 'smp-core-2020-03-30' of ↵Linus Torvalds1-2/+2
git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip Pull core SMP updates from Thomas Gleixner: "CPU (hotplug) updates: - Support for locked CSD objects in smp_call_function_single_async() which allows to simplify callsites in the scheduler core and MIPS - Treewide consolidation of CPU hotplug functions which ensures the consistency between the sysfs interface and kernel state. The low level functions cpu_up/down() are now confined to the core code and not longer accessible from random code" * tag 'smp-core-2020-03-30' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip: (22 commits) cpu/hotplug: Ignore pm_wakeup_pending() for disable_nonboot_cpus() cpu/hotplug: Hide cpu_up/down() cpu/hotplug: Move bringup of secondary CPUs out of smp_init() torture: Replace cpu_up/down() with add/remove_cpu() firmware: psci: Replace cpu_up/down() with add/remove_cpu() xen/cpuhotplug: Replace cpu_up/down() with device_online/offline() parisc: Replace cpu_up/down() with add/remove_cpu() sparc: Replace cpu_up/down() with add/remove_cpu() powerpc: Replace cpu_up/down() with add/remove_cpu() x86/smp: Replace cpu_up/down() with add/remove_cpu() arm64: hibernate: Use bringup_hibernate_cpu() cpu/hotplug: Provide bringup_hibernate_cpu() arm64: Use reboot_cpu instead of hardconding it to 0 arm64: Don't use disable_nonboot_cpus() ARM: Use reboot_cpu instead of hardcoding it to 0 ARM: Don't use disable_nonboot_cpus() ia64: Replace cpu_down() with smp_shutdown_nonboot_cpus() cpu/hotplug: Create a new function to shutdown nonboot cpus cpu/hotplug: Add new {add,remove}_cpu() functions sched/core: Remove rq.hrtick_csd_pending ...
2020-03-25cpu/hotplug: Hide cpu_up/down()Qais Yousef1-2/+2
Use separate functions for the device core to bring a CPU up and down. Users outside the device core must use add/remove_cpu() which will take care of extra housekeeping work like keeping sysfs in sync. Make cpu_up/down() static and replace the extra layer of indirection. [ tglx: Removed the extra wrapper functions and adjusted function names ] Signed-off-by: Qais Yousef <qais.yousef@arm.com> Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Link: https://lkml.kernel.org/r/20200323135110.30522-18-qais.yousef@arm.com
2020-03-11drivers/base/cpu: Simplify s*nprintf() usagesTakashi Iwai1-9/+4
Use the simpler sprintf() instead of snprintf() or scnprintf() in a single-shot sysfs output callbacks where you are very sure that it won't go over PAGE_SIZE buffer limit. Signed-off-by: Takashi Iwai <tiwai@suse.de> Link: https://lore.kernel.org/r/20200311080207.12046-3-tiwai@suse.de Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2020-03-11drivers/base/cpu: Use scnprintf() for avoiding potential buffer overflowTakashi Iwai1-3/+3
Since snprintf() returns the would-be-output size instead of the actual output size, the succeeding calls may go beyond the given buffer limit. Fix it by replacing with scnprintf(). Signed-off-by: Takashi Iwai <tiwai@suse.de> Link: https://lore.kernel.org/r/20200311080207.12046-2-tiwai@suse.de Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2019-11-04x86/bugs: Add ITLB_MULTIHIT bug infrastructureVineela Tummalapalli1-0/+8
Some processors may incur a machine check error possibly resulting in an unrecoverable CPU lockup when an instruction fetch encounters a TLB multi-hit in the instruction TLB. This can occur when the page size is changed along with either the physical address or cache type. The relevant erratum can be found here: https://bugzilla.kernel.org/show_bug.cgi?id=205195 There are other processors affected for which the erratum does not fully disclose the impact. This issue affects both bare-metal x86 page tables and EPT. It can be mitigated by either eliminating the use of large pages or by using careful TLB invalidations when changing the page size in the page tables. Just like Spectre, Meltdown, L1TF and MDS, a new bit has been allocated in MSR_IA32_ARCH_CAPABILITIES (PSCHANGE_MC_NO) and will be set on CPUs which are mitigated against this issue. Signed-off-by: Vineela Tummalapalli <vineela.tummalapalli@intel.com> Co-developed-by: Pawan Gupta <pawan.kumar.gupta@linux.intel.com> Signed-off-by: Pawan Gupta <pawan.kumar.gupta@linux.intel.com> Signed-off-by: Paolo Bonzini <pbonzini@redhat.com> Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
2019-10-28x86/speculation/taa: Add sysfs reporting for TSX Async AbortPawan Gupta1-0/+9
Add the sysfs reporting file for TSX Async Abort. It exposes the vulnerability and the mitigation state similar to the existing files for the other hardware vulnerabilities. Sysfs file path is: /sys/devices/system/cpu/vulnerabilities/tsx_async_abort Signed-off-by: Pawan Gupta <pawan.kumar.gupta@linux.intel.com> Signed-off-by: Borislav Petkov <bp@suse.de> Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Tested-by: Neelima Krishnan <neelima.krishnan@intel.com> Reviewed-by: Mark Gross <mgross@linux.intel.com> Reviewed-by: Tony Luck <tony.luck@intel.com> Reviewed-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org> Reviewed-by: Josh Poimboeuf <jpoimboe@redhat.com>
2019-05-14Merge branch 'x86-mds-for-linus' of ↵Linus Torvalds1-0/+8
git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip Pull x86 MDS mitigations from Thomas Gleixner: "Microarchitectural Data Sampling (MDS) is a hardware vulnerability which allows unprivileged speculative access to data which is available in various CPU internal buffers. This new set of misfeatures has the following CVEs assigned: CVE-2018-12126 MSBDS Microarchitectural Store Buffer Data Sampling CVE-2018-12130 MFBDS Microarchitectural Fill Buffer Data Sampling CVE-2018-12127 MLPDS Microarchitectural Load Port Data Sampling CVE-2019-11091 MDSUM Microarchitectural Data Sampling Uncacheable Memory MDS attacks target microarchitectural buffers which speculatively forward data under certain conditions. Disclosure gadgets can expose this data via cache side channels. Contrary to other speculation based vulnerabilities the MDS vulnerability does not allow the attacker to control the memory target address. As a consequence the attacks are purely sampling based, but as demonstrated with the TLBleed attack samples can be postprocessed successfully. The mitigation is to flush the microarchitectural buffers on return to user space and before entering a VM. It's bolted on the VERW instruction and requires a microcode update. As some of the attacks exploit data structures shared between hyperthreads, full protection requires to disable hyperthreading. The kernel does not do that by default to avoid breaking unattended updates. The mitigation set comes with documentation for administrators and a deeper technical view" * 'x86-mds-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip: (23 commits) x86/speculation/mds: Fix documentation typo Documentation: Correct the possible MDS sysfs values x86/mds: Add MDSUM variant to the MDS documentation x86/speculation/mds: Add 'mitigations=' support for MDS x86/speculation/mds: Print SMT vulnerable on MSBDS with mitigations off x86/speculation/mds: Fix comment x86/speculation/mds: Add SMT warning message x86/speculation: Move arch_smt_update() call to after mitigation decisions x86/speculation/mds: Add mds=full,nosmt cmdline option Documentation: Add MDS vulnerability documentation Documentation: Move L1TF to separate directory x86/speculation/mds: Add mitigation mode VMWERV x86/speculation/mds: Add sysfs reporting for MDS x86/speculation/mds: Add mitigation control for MDS x86/speculation/mds: Conditionally clear CPU buffers on idle entry x86/kvm/vmx: Add MDS protection when L1D Flush is not active x86/speculation/mds: Clear CPU buffers on exit to user x86/speculation/mds: Add mds_clear_cpu_buffers() x86/kvm: Expose X86_FEATURE_MD_CLEAR to guests x86/speculation/mds: Add BUG_MSBDS_ONLY ...
2019-03-07Merge tag 'driver-core-5.1-rc1' of ↵Linus Torvalds1-0/+1
git://git.kernel.org/pub/scm/linux/kernel/git/gregkh/driver-core Pull driver core updates from Greg KH: "Here is the big driver core patchset for 5.1-rc1 More patches than "normal" here this merge window, due to some work in the driver core by Alexander Duyck to rework the async probe functionality to work better for a number of devices, and independant work from Rafael for the device link functionality to make it work "correctly". Also in here is: - lots of BUS_ATTR() removals, the macro is about to go away - firmware test fixups - ihex fixups and simplification - component additions (also includes i915 patches) - lots of minor coding style fixups and cleanups. All of these have been in linux-next for a while with no reported issues" * tag 'driver-core-5.1-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/gregkh/driver-core: (65 commits) driver core: platform: remove misleading err_alloc label platform: set of_node in platform_device_register_full() firmware: hardcode the debug message for -ENOENT driver core: Add missing description of new struct device_link field driver core: Fix PM-runtime for links added during consumer probe drivers/component: kerneldoc polish async: Add cmdline option to specify drivers to be async probed driver core: Fix possible supplier PM-usage counter imbalance PM-runtime: Fix __pm_runtime_set_status() race with runtime resume driver: platform: Support parsing GpioInt 0 in platform_get_irq() selftests: firmware: fix verify_reqs() return value Revert "selftests: firmware: remove use of non-standard diff -Z option" Revert "selftests: firmware: add CONFIG_FW_LOADER_USER_HELPER_FALLBACK to config" device: Fix comment for driver_data in struct device kernfs: Allocating memory for kernfs_iattrs with kmem_cache. sysfs: remove unused include of kernfs-internal.h driver core: Postpone DMA tear-down until after devres release driver core: Document limitation related to DL_FLAG_RPM_ACTIVE PM-runtime: Take suppliers into account in __pm_runtime_set_status() device.h: Add __cold to dev_<level> logging functions ...
2019-03-06x86/speculation/mds: Add sysfs reporting for MDSThomas Gleixner1-0/+8
Add the sysfs reporting file for MDS. It exposes the vulnerability and mitigation state similar to the existing files for the other speculative hardware vulnerabilities. Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Reviewed-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org> Reviewed-by: Borislav Petkov <bp@suse.de> Reviewed-by: Jon Masters <jcm@redhat.com> Tested-by: Jon Masters <jcm@redhat.com>
2019-02-19PM / core: Add support to skip power management in device/driver modelSudeep Holla1-0/+1
All device objects in the driver model contain fields that control the handling of various power management activities. However, it's not always useful. There are few instances where pseudo devices are added to the model just to take advantage of many other features like kobjects, udev events, and so on. One such example is cpu devices and their caches. The sysfs for the cpu caches are managed by adding devices with cpu as the parent in cpu_device_create() when secondary cpu is brought online. Generally when the secondary CPUs are hotplugged back in as part of resume from suspend-to-ram, we call cpu_device_create() from the cpu hotplug state machine while the cpu device associated with that CPU is not yet ready to be resumed as the device_resume() call happens bit later. It's not really needed to set the flag is_prepared for cpu devices as they are mostly pseudo device and hotplug framework deals with state machine and not managed through the cpu device. This often results in annoying warning when resuming: Enabling non-boot CPUs ... CPU1: Booted secondary processor cache: parent cpu1 should not be sleeping CPU1 is up CPU2: Booted secondary processor cache: parent cpu2 should not be sleeping CPU2 is up .... and so on. So in order to fix these kind of errors, we could just completely avoid doing any power management related initialisations and operations if they are not used by these devices. Add no_pm flags to indicate that the device doesn't require any sort of PM activities and all of them can be completely skipped. We can use the same flag to also avoid adding not used *power* sysfs entries for these devices. For now, lets use this for cpu cache devices. Reviewed-by: Ulf Hansson <ulf.hansson@linaro.org> Signed-off-by: Sudeep Holla <sudeep.holla@arm.com> Tested-by: Eugeniu Rosca <erosca@de.adit-jv.com> Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
2019-01-31drivers: base: Use __printf markup to silence compilerMathieu Malaterre1-0/+1
Silence warnings (triggered at W=1) by adding relevant __printf attributes. drivers/base/cpu.c:432:2: warning: function '__cpu_device_create' might be a candidate for 'gnu_printf' format attribute [-Wsuggest-attribute=format] Signed-off-by: Mathieu Malaterre <malat@debian.org> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2018-06-20x86/speculation/l1tf: Add sysfs reporting for l1tfAndi Kleen1-0/+8
L1TF core kernel workarounds are cheap and normally always enabled, However they still should be reported in sysfs if the system is vulnerable or mitigated. Add the necessary CPU feature/bug bits. - Extend the existing checks for Meltdowns to determine if the system is vulnerable. All CPUs which are not vulnerable to Meltdown are also not vulnerable to L1TF - Check for 32bit non PAE and emit a warning as there is no practical way for mitigation due to the limited physical address bits - If the system has more than MAX_PA/2 physical memory the invert page workarounds don't protect the system against the L1TF attack anymore, because an inverted physical address will also point to valid memory. Print a warning in this case and report that the system is vulnerable. Add a function which returns the PFN limit for the L1TF mitigation, which will be used in follow up patches for sanity and range checks. [ tglx: Renamed the CPU feature bit to L1TF_PTEINV ] Signed-off-by: Andi Kleen <ak@linux.intel.com> Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Reviewed-by: Josh Poimboeuf <jpoimboe@redhat.com> Acked-by: Dave Hansen <dave.hansen@intel.com>
2018-05-03x86/bugs: Expose /sys/../spec_store_bypassKonrad Rzeszutek Wilk1-0/+8
Add the sysfs file for the new vulerability. It does not do much except show the words 'Vulnerable' for recent x86 cores. Intel cores prior to family 6 are known not to be vulnerable, and so are some Atoms and some Xeon Phi. It assumes that older Cyrix, Centaur, etc. cores are immune. Signed-off-by: Konrad Rzeszutek Wilk <konrad.wilk@oracle.com> Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Reviewed-by: Borislav Petkov <bp@suse.de> Reviewed-by: Ingo Molnar <mingo@kernel.org>
2018-03-15driver core: cpu: use put_device() if device_register failArvind Yadav1-1/+3
if device_register() returned an error! Always use put_device() to give up the reference initialized. Signed-off-by: Arvind Yadav <arvind.yadav.cs@gmail.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2018-02-01Merge tag 'driver-core-4.16-rc1' of ↵Linus Torvalds1-0/+1
git://git.kernel.org/pub/scm/linux/kernel/git/gregkh/driver-core Pull driver core updates from Greg KH: "Here is the set of "big" driver core patches for 4.16-rc1. The majority of the work here is in the firmware subsystem, with reworks to try to attempt to make the code easier to handle in the long run, but no functional change. There's also some tree-wide sysfs attribute fixups with lots of acks from the various subsystem maintainers, as well as a handful of other normal fixes and changes. And finally, some license cleanups for the driver core and sysfs code. All have been in linux-next for a while with no reported issues" * tag 'driver-core-4.16-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/gregkh/driver-core: (48 commits) device property: Define type of PROPERTY_ENRTY_*() macros device property: Reuse property_entry_free_data() device property: Move property_entry_free_data() upper firmware: Fix up docs referring to FIRMWARE_IN_KERNEL firmware: Drop FIRMWARE_IN_KERNEL Kconfig option USB: serial: keyspan: Drop firmware Kconfig options sysfs: remove DEBUG defines sysfs: use SPDX identifiers drivers: base: add coredump driver ops sysfs: add attribute specification for /sysfs/devices/.../coredump test_firmware: fix missing unlock on error in config_num_requests_store() test_firmware: make local symbol test_fw_config static sysfs: turn WARN() into pr_warn() firmware: Fix a typo in fallback-mechanisms.rst treewide: Use DEVICE_ATTR_WO treewide: Use DEVICE_ATTR_RO treewide: Use DEVICE_ATTR_RW sysfs.h: Use octal permissions component: add debugfs support bus: simple-pm-bus: convert bool SIMPLE_PM_BUS to tristate ...
2018-01-14Merge branch 'x86-pti-for-linus' of ↵Linus Torvalds1-0/+48
git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip Pull x86 pti updates from Thomas Gleixner: "This contains: - a PTI bugfix to avoid setting reserved CR3 bits when PCID is disabled. This seems to cause issues on a virtual machine at least and is incorrect according to the AMD manual. - a PTI bugfix which disables the perf BTS facility if PTI is enabled. The BTS AUX buffer is not globally visible and causes the CPU to fault when the mapping disappears on switching CR3 to user space. A full fix which restores BTS on PTI is non trivial and will be worked on. - PTI bugfixes for EFI and trusted boot which make sure that the user space visible page table entries have the NX bit cleared - removal of dead code in the PTI pagetable setup functions - add PTI documentation - add a selftest for vsyscall to verify that the kernel actually implements what it advertises. - a sysfs interface to expose vulnerability and mitigation information so there is a coherent way for users to retrieve the status. - the initial spectre_v2 mitigations, aka retpoline: + The necessary ASM thunk and compiler support + The ASM variants of retpoline and the conversion of affected ASM code + Make LFENCE serializing on AMD so it can be used as speculation trap + The RSB fill after vmexit - initial objtool support for retpoline As I said in the status mail this is the most of the set of patches which should go into 4.15 except two straight forward patches still on hold: - the retpoline add on of LFENCE which waits for ACKs - the RSB fill after context switch Both should be ready to go early next week and with that we'll have covered the major holes of spectre_v2 and go back to normality" * 'x86-pti-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip: (28 commits) x86,perf: Disable intel_bts when PTI security/Kconfig: Correct the Documentation reference for PTI x86/pti: Fix !PCID and sanitize defines selftests/x86: Add test_vsyscall x86/retpoline: Fill return stack buffer on vmexit x86/retpoline/irq32: Convert assembler indirect jumps x86/retpoline/checksum32: Convert assembler indirect jumps x86/retpoline/xen: Convert Xen hypercall indirect jumps x86/retpoline/hyperv: Convert assembler indirect jumps x86/retpoline/ftrace: Convert ftrace assembler indirect jumps x86/retpoline/entry: Convert entry assembler indirect jumps x86/retpoline/crypto: Convert crypto assembler indirect jumps x86/spectre: Add boot time option to select Spectre v2 mitigation x86/retpoline: Add initial retpoline support objtool: Allow alternatives to be ignored objtool: Detect jumps to retpoline thunks x86/pti: Make unpoison of pgd for trusted boot work for real x86/alternatives: Fix optimize_nops() checking sysfs/cpu: Fix typos in vulnerability documentation x86/cpu/AMD: Use LFENCE_RDTSC in preference to MFENCE_RDTSC ...
2018-01-08sysfs/cpu: Add vulnerability folderThomas Gleixner1-0/+48
As the meltdown/spectre problem affects several CPU architectures, it makes sense to have common way to express whether a system is affected by a particular vulnerability or not. If affected the way to express the mitigation should be common as well. Create /sys/devices/system/cpu/vulnerabilities folder and files for meltdown, spectre_v1 and spectre_v2. Allow architectures to override the show function. Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Reviewed-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org> Reviewed-by: Konrad Rzeszutek Wilk <konrad.wilk@oracle.com> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Will Deacon <will.deacon@arm.com> Cc: Dave Hansen <dave.hansen@intel.com> Cc: Linus Torvalds <torvalds@linuxfoundation.org> Cc: Borislav Petkov <bp@alien8.de> Cc: David Woodhouse <dwmw@amazon.co.uk> Link: https://lkml.kernel.org/r/20180107214913.096657732@linutronix.de
2017-12-07driver core: add SPDX identifiers to all driver core filesGreg Kroah-Hartman1-0/+1
It's good to have SPDX identifiers in all files to make it easier to audit the kernel tree for correct licenses. Update the driver core files files with the correct SPDX license identifier based on the license text in the file itself. The SPDX identifier is a legally binding shorthand, which can be used instead of the full boiler plate text. This work is based on a script and data from Thomas Gleixner, Philippe Ombredanne, and Kate Stewart. Cc: Johannes Berg <johannes@sipsolutions.net> Cc: "Luis R. Rodriguez" <mcgrof@kernel.org> Cc: William Breathitt Gray <vilhelm.gray@gmail.com> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: Kate Stewart <kstewart@linuxfoundation.org> Cc: Philippe Ombredanne <pombredanne@nexb.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2017-11-14Merge tag 'pm-4.15-rc1' of ↵Linus Torvalds1-1/+2
git://git.kernel.org/pub/scm/linux/kernel/git/rafael/linux-pm Pull power management updates from Rafael Wysocki: "There are no real big ticket items here this time. The most noticeable change is probably the relocation of the OPP (Operating Performance Points) framework to its own directory under drivers/ as it has grown big enough for that. Also Viresh is now going to maintain it and send pull requests for it to me, so you will see this change in the git history going forward (but still not right now). Another noticeable set of changes is the modifications of the PM core, the PCI subsystem and the ACPI PM domain to allow of more integration between system-wide suspend/resume and runtime PM. For now it's just a way to avoid resuming devices from runtime suspend unnecessarily during system suspend (if the driver sets a flag to indicate its readiness for that) and in the works is an analogous mechanism to allow devices to stay suspended after system resume. In addition to that, we have some changes related to supporting frequency-invariant CPU utilization metrics in the scheduler and in the schedutil cpufreq governor on ARM and changes to add support for device performance states to the generic power domains (genpd) framework. The rest is mostly fixes and cleanups of various sorts. Specifics: - Relocate the OPP (Operating Performance Points) framework to its own directory under drivers/ and add support for power domain performance states to it (Viresh Kumar). - Modify the PM core, the PCI bus type and the ACPI PM domain to support power management driver flags allowing device drivers to specify their capabilities and preferences regarding the handling of devices with enabled runtime PM during system suspend/resume and clean up that code somewhat (Rafael Wysocki, Ulf Hansson). - Add frequency-invariant accounting support to the task scheduler on ARM and ARM64 (Dietmar Eggemann). - Fix PM QoS device resume latency framework to prevent "no restriction" requests from overriding requests with specific requirements and drop the confusing PM_QOS_FLAG_REMOTE_WAKEUP device PM QoS flag (Rafael Wysocki). - Drop legacy class suspend/resume operations from the PM core and drop legacy bus type suspend and resume callbacks from ARM/locomo (Rafael Wysocki). - Add min/max frequency support to devfreq and clean it up somewhat (Chanwoo Choi). - Rework wakeup support in the generic power domains (genpd) framework and update some of its users accordingly (Geert Uytterhoeven). - Convert timers in the PM core to use timer_setup() (Kees Cook). - Add support for exposing the SLP_S0 (Low Power S0 Idle) residency counter based on the LPIT ACPI table on Intel platforms (Srinivas Pandruvada). - Add per-CPU PM QoS resume latency support to the ladder cpuidle governor (Ramesh Thomas). - Fix a deadlock between the wakeup notify handler and the notifier removal in the ACPI core (Ville Syrjälä). - Fix a cpufreq schedutil governor issue causing it to use stale cached frequency values sometimes (Viresh Kumar). - Fix an issue in the system suspend core support code causing wakeup events detection to fail in some cases (Rajat Jain). - Fix the generic power domains (genpd) framework to prevent the PM core from using the direct-complete optimization with it as that is guaranteed to fail (Ulf Hansson). - Fix a minor issue in the cpuidle core and clean it up a bit (Gaurav Jindal, Nicholas Piggin). - Fix and clean up the intel_idle and ARM cpuidle drivers (Jason Baron, Len Brown, Leo Yan). - Fix a couple of minor issues in the OPP framework and clean it up (Arvind Yadav, Fabio Estevam, Sudeep Holla, Tobias Jordan). - Fix and clean up some cpufreq drivers and fix a minor issue in the cpufreq statistics code (Arvind Yadav, Bhumika Goyal, Fabio Estevam, Gautham Shenoy, Gustavo Silva, Marek Szyprowski, Masahiro Yamada, Robert Jarzmik, Zumeng Chen). - Fix minor issues in the system suspend and hibernation core, in power management documentation and in the AVS (Adaptive Voltage Scaling) framework (Helge Deller, Himanshu Jha, Joe Perches, Rafael Wysocki). - Fix some issues in the cpupower utility and document that Shuah Khan is going to maintain it going forward (Prarit Bhargava, Shuah Khan)" * tag 'pm-4.15-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/rafael/linux-pm: (88 commits) tools/power/cpupower: add libcpupower.so.0.0.1 to .gitignore tools/power/cpupower: Add 64 bit library detection intel_idle: Graceful probe failure when MWAIT is disabled cpufreq: schedutil: Reset cached_raw_freq when not in sync with next_freq freezer: Fix typo in freezable_schedule_timeout() comment PM / s2idle: Clear the events_check_enabled flag cpufreq: stats: Handle the case when trans_table goes beyond PAGE_SIZE cpufreq: arm_big_little: make cpufreq_arm_bL_ops structures const cpufreq: arm_big_little: make function arguments and structure pointer const cpuidle: Avoid assignment in if () argument cpuidle: Clean up cpuidle_enable_device() error handling a bit ACPI / PM: Fix acpi_pm_notifier_lock vs flush_workqueue() deadlock PM / Domains: Fix genpd to deal with drivers returning 1 from ->prepare() cpuidle: ladder: Add per CPU PM QoS resume latency support PM / QoS: Fix device resume latency framework PM / domains: Rework governor code to be more consistent PM / Domains: Remove gpd_dev_ops.active_wakeup() callback soc: rockchip: power-domain: Use GENPD_FLAG_ACTIVE_WAKEUP soc: mediatek: Use GENPD_FLAG_ACTIVE_WAKEUP ARM: shmobile: pm-rmobile: Use GENPD_FLAG_ACTIVE_WAKEUP ...
2017-11-08PM / QoS: Fix device resume latency frameworkRafael J. Wysocki1-1/+2
The special value of 0 for device resume latency PM QoS means "no restriction", but there are two problems with that. First, device resume latency PM QoS requests with 0 as the value are always put in front of requests with positive values in the priority lists used internally by the PM QoS framework, causing 0 to be chosen as an effective constraint value. However, that 0 is then interpreted as "no restriction" effectively overriding the other requests with specific restrictions which is incorrect. Second, the users of device resume latency PM QoS have no way to specify that *any* resume latency at all should be avoided, which is an artificial limitation in general. To address these issues, modify device resume latency PM QoS to use S32_MAX as the "no constraint" value and 0 as the "no latency at all" one and rework its users (the cpuidle menu governor, the genpd QoS governor and the runtime PM framework) to follow these changes. Also add a special "n/a" value to the corresponding user space I/F to allow user space to indicate that it cannot accept any resume latencies at all for the given device. Fixes: 85dc0b8a4019 (PM / QoS: Make it possible to expose PM QoS latency constraints) Link: https://bugzilla.kernel.org/show_bug.cgi?id=197323 Reported-by: Reinette Chatre <reinette.chatre@intel.com> Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com> Tested-by: Reinette Chatre <reinette.chatre@intel.com> Tested-by: Geert Uytterhoeven <geert+renesas@glider.be> Tested-by: Tero Kristo <t-kristo@ti.com> Reviewed-by: Ramesh Thomas <ramesh.thomas@intel.com>
2017-10-31Revert "PM / QoS: Fix device resume latency PM QoS"Rafael J. Wysocki1-2/+1
This reverts commit 0cc2b4e5a020 (PM / QoS: Fix device resume latency PM QoS) as it introduced regressions on multiple systems and the fix-up in commit 2a9a86d5c813 (PM / QoS: Fix default runtime_pm device resume latency) does not address all of them. The original problem that commit 0cc2b4e5a020 was attempting to fix will be addressed later. Fixes: 0cc2b4e5a020 (PM / QoS: Fix device resume latency PM QoS) Reported-by: Geert Uytterhoeven <geert@linux-m68k.org> Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
2017-10-27sched/isolation: Move isolcpus= handling to the housekeeping codeFrederic Weisbecker1-1/+10
We want to centralize the isolation features, to be done by the housekeeping subsystem and scheduler domain isolation is a significant part of it. No intended behaviour change, we just reuse the housekeeping cpumask and core code. Signed-off-by: Frederic Weisbecker <frederic@kernel.org> Acked-by: Thomas Gleixner <tglx@linutronix.de> Cc: Chris Metcalf <cmetcalf@mellanox.com> Cc: Christoph Lameter <cl@linux.com> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Luiz Capitulino <lcapitulino@redhat.com> Cc: Mike Galbraith <efault@gmx.de> Cc: Paul E. McKenney <paulmck@linux.vnet.ibm.com> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Rik van Riel <riel@redhat.com> Cc: Wanpeng Li <kernellwp@gmail.com> Link: http://lkml.kernel.org/r/1509072159-31808-11-git-send-email-frederic@kernel.org Signed-off-by: Ingo Molnar <mingo@kernel.org>
2017-10-24PM / QoS: Fix device resume latency PM QoSRafael J. Wysocki1-1/+2
The special value of 0 for device resume latency PM QoS means "no restriction", but there are two problems with that. First, device resume latency PM QoS requests with 0 as the value are always put in front of requests with positive values in the priority lists used internally by the PM QoS framework, causing 0 to be chosen as an effective constraint value. However, that 0 is then interpreted as "no restriction" effectively overriding the other requests with specific restrictions which is incorrect. Second, the users of device resume latency PM QoS have no way to specify that *any* resume latency at all should be avoided, which is an artificial limitation in general. To address these issues, modify device resume latency PM QoS to use S32_MAX as the "no constraint" value and 0 as the "no latency at all" one and rework its users (the cpuidle menu governor, the genpd QoS governor and the runtime PM framework) to follow these changes. Also add a special "n/a" value to the corresponding user space I/F to allow user space to indicate that it cannot accept any resume latencies at all for the given device. Fixes: 85dc0b8a4019 (PM / QoS: Make it possible to expose PM QoS latency constraints) Link: https://bugzilla.kernel.org/show_bug.cgi?id=197323 Reported-by: Reinette Chatre <reinette.chatre@intel.com> Tested-by: Reinette Chatre <reinette.chatre@intel.com> Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com> Acked-by: Alex Shi <alex.shi@linaro.org> Cc: All applicable <stable@vger.kernel.org>
2017-09-09treewide: make "nr_cpu_ids" unsignedAlexey Dobriyan1-2/+2
First, number of CPUs can't be negative number. Second, different signnnedness leads to suboptimal code in the following cases: 1) kmalloc(nr_cpu_ids * sizeof(X)); "int" has to be sign extended to size_t. 2) while (loff_t *pos < nr_cpu_ids) MOVSXD is 1 byte longed than the same MOV. Other cases exist as well. Basically compiler is told that nr_cpu_ids can't be negative which can't be deduced if it is "int". Code savings on allyesconfig kernel: -3KB add/remove: 0/0 grow/shrink: 25/264 up/down: 261/-3631 (-3370) function old new delta coretemp_cpu_online 450 512 +62 rcu_init_one 1234 1272 +38 pci_device_probe 374 399 +25 ... pgdat_reclaimable_pages 628 556 -72 select_fallback_rq 446 369 -77 task_numa_find_cpu 1923 1807 -116 Link: http://lkml.kernel.org/r/20170819114959.GA30580@avx2 Signed-off-by: Alexey Dobriyan <adobriyan@gmail.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2017-01-30CPU / PM: expose pm_qos_resume_latency for CPUsAlex Shi1-0/+2
The cpu-dma PM QoS constraint impacts all the cpus in the system. There is no way to let the user to choose a PM QoS constraint per cpu. The following patch exposes to the userspace a per cpu based sysfs file in order to let the userspace to change the value of the PM QoS latency constraint. This change is inoperative in its form and the cpuidle governors have to take into account the per cpu latency constraint in addition to the global cpu-dma latency constraint in order to operate properly. BTW The pm_qos_resume_latency usage defined in Documentation/ABI/testing/sysfs-devices-power The /sys/devices/.../power/pm_qos_resume_latency_us attribute contains the PM QoS resume latency limit for the given device, which is the maximum allowed time it can take to resume the device, after it has been suspended at run time, from a resume request to the moment the device will be ready to process I/O, in microseconds. If it is equal to 0, however, this means that the PM QoS resume latency may be arbitrary. Signed-off-by: Alex Shi <alex.shi@linaro.org> Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
2016-08-31cpu: clean up register_cpu funcAlex Shi1-5/+6
This patch could reduce one branch in this function. Also make the code more readble. Signed-off-by: Alex Shi <alex.shi@linaro.org> Acked-by: Daniel Lezcano <daniel.lezcano@linaro.org> To: linux-kernel@vger.kernel.org To: Greg Kroah-Hartman <gregkh@linuxfoundation.org> Cc: linux-pm@vger.kernel.org Cc: Ulf Hansson <ulf.hansson@linaro.org> Cc: Daniel Lezcano <daniel.lezcano@linaro.org> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2016-01-21drivers/base/cpu.c: use __cpu_*_mask directlyRasmus Villemoes1-5/+5
The only user of the lvalue-ness of the cpu_*_mask variables is in drivers/base/cpu.c, and that is mostly a work-around for the fact that not even const variables can be used in static initialization. Now that the underlying struct cpumasks are exposed we can take their address. Signed-off-by: Rasmus Villemoes <linux@rasmusvillemoes.dk> Acked-by: Rusty Russell <rusty@rustcorp.com.au> Acked-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org> Cc: Michael Ellerman <mpe@ellerman.id.au> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2015-08-06cpu: Remove bogus __ref annotation of cpu_subsys_online()Mathias Krause1-1/+1
In commit 0db0628d9012 ("kernel: delete __cpuinit usage from all core kernel files") cpu_up() lost its __cpuinit annotation, vanishing the need for cpu_subsys_online() to have a __ref annotation. Just drop it to be able to catch real section mismatches in the future. Signed-off-by: Mathias Krause <minipli@googlemail.com> Cc: Paul Gortmaker <paul.gortmaker@windriver.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2015-05-20show nohz_full cpus in sysfsRik van Riel1-0/+17
Currently there is no way to query which CPUs are in nohz_full mode from userspace. Export the CPU list running in nohz_full mode in sysfs, specifically in the file /sys/devices/system/cpu/nohz_full This can be used by system management tools like libvirt, openstack, and others to ensure proper task placement. Signed-off-by: Rik van Riel <riel@redhat.com> Acked-by: Mike Galbraith <umgwanakikbuti@gmail.com> Acked-by: Chris Metcalf <cmetcalf@ezchip.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2015-05-20show isolated cpus in sysfsRik van Riel1-0/+12
After system bootup, there is no totally reliable way to see which CPUs are isolated, because the kernel may modify the CPUs specified on the isolcpus= kernel command line option. Export the CPU list that actually got isolated in sysfs, specifically in the file /sys/devices/system/cpu/isolated This can be used by system management tools like libvirt, openstack, and others to ensure proper placement of tasks. Suggested-by: Li Zefan <lizefan@huawei.com> Signed-off-by: Rik van Riel <riel@redhat.com> Acked-by: Mike Galbraith <umgwanakikbuti@gmail.com> Acked-by: Chris Metcalf <cmetcalf@ezchip.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2015-02-14drivers/base: use %*pb[l] to print bitmaps including cpumasks and nodemasksTejun Heo1-1/+1
printk and friends can now format bitmaps using '%*pb[l]'. cpumask and nodemask also provide cpumask_pr_args() and nodemask_pr_args() respectively which can be used to generate the two printf arguments necessary to format the specified cpu/nodemask. * Line termination only requires one extra space at the end of the buffer. Use PAGE_SIZE - 1 instead of PAGE_SIZE - 2 when formatting. Signed-off-by: Tejun Heo <tj@kernel.org> Acked-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2014-11-07drivers: base: add cpu_device_create to support per-cpu devicesSudeep Holla1-0/+54
This patch adds a new function to create per-cpu devices. This helps in: 1. reusing the device infrastructure to create any cpu related attributes and corresponding sysfs instead of creating and dealing with raw kobjects directly 2. retaining the legacy path(/sys/devices/system/cpu/..) to support existing sysfs ABI 3. avoiding to create links in the bus directory pointing to the device as there would be per-cpu instance of these devices with the same name since dev->bus is not populated to cpu_sysbus on purpose Signed-off-by: Sudeep Holla <sudeep.holla@arm.com> Tested-by: Stephen Boyd <sboyd@codeaurora.org> Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org> Cc: David Herrmann <dh.herrmann@gmail.com> Cc: Kay Sievers <kay@vrfy.org> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2014-11-07cpumask: factor out show_cpumap into separate helper functionSudeep Holla1-4/+1
Many sysfs *_show function use cpu{list,mask}_scnprintf to copy cpumap to the buffer aligned to PAGE_SIZE, append '\n' and '\0' to return null terminated buffer with newline. This patch creates a new helper function cpumap_print_to_pagebuf in cpumask.h using newly added bitmap_print_to_pagebuf and consolidates most of those sysfs functions using the new helper function. Signed-off-by: Sudeep Holla <sudeep.holla@arm.com> Suggested-by: Stephen Boyd <sboyd@codeaurora.org> Tested-by: Stephen Boyd <sboyd@codeaurora.org> Acked-by: "Rafael J. Wysocki" <rjw@rjwysocki.net> Acked-by: Bjorn Helgaas <bhelgaas@google.com> Acked-by: Peter Zijlstra (Intel) <peterz@infradead.org> Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org> Cc: x86@kernel.org Cc: linux-acpi@vger.kernel.org Cc: linux-pci@vger.kernel.org Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2014-02-19x86: align x86 arch with generic CPU modalias handlingArd Biesheuvel1-7/+3
The x86 CPU feature modalias handling existed before it was reimplemented generically. This patch aligns the x86 handling so that it (a) reuses some more code that is now generic; (b) uses the generic format for the modalias module metadata entry, i.e., it now uses 'cpu:type:x86,venVVVVfamFFFFmodMMMM:feature:,XXXX,YYYY' instead of the 'x86cpu:vendor:VVVV:family:FFFF:model:MMMM:feature:,XXXX,YYYY' that was used before. Signed-off-by: Ard Biesheuvel <ard.biesheuvel@linaro.org> Acked-by: H. Peter Anvin <hpa@linux.intel.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2014-02-19cpu: add generic support for CPU feature based module autoloadingArd Biesheuvel1-5/+45
This patch adds support for advertising optional CPU features over udev using the modalias, and for declaring compatibility with/dependency upon such a feature in a module. The mapping between feature numbers and actual features should be provided by the architecture in a file called <asm/cpufeature.h> which exports the following functions/macros: - cpu_feature(FEAT), a preprocessor macro that maps token FEAT to a numeric index; - bool cpu_have_feature(n), returning whether this CPU has support for feature #n; - MAX_CPU_FEATURES, an upper bound for 'n' in the previous function. The feature can then be enabled by setting CONFIG_GENERIC_CPU_AUTOPROBE for the architecture. For instance, a module that registers its module init function using module_cpu_feature_match(FEAT_X, module_init_function) will be probed automatically when the CPU's support for the 'FEAT_X' feature is advertised over udev, and will only allow the module to be loaded by hand if the 'FEAT_X' feature is supported. Signed-off-by: Ard Biesheuvel <ard.biesheuvel@linaro.org> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2013-09-30hotplug, powerpc, x86: Remove cpu_hotplug_driver_lock()Toshi Kani1-12/+3
cpu_hotplug_driver_lock() serializes CPU online/offline operations when ARCH_CPU_PROBE_RELEASE is set. This lock interface is no longer necessary with the following reason: - lock_device_hotplug() now protects CPU online/offline operations, including the probe & release interfaces enabled by ARCH_CPU_PROBE_RELEASE. The use of cpu_hotplug_driver_lock() is redundant. - cpu_hotplug_driver_lock() is only valid when ARCH_CPU_PROBE_RELEASE is defined, which is misleading and is only enabled on powerpc. This patch removes the cpu_hotplug_driver_lock() interface. As a result, ARCH_CPU_PROBE_RELEASE only enables / disables the cpu probe & release interface as intended. There is no functional change in this patch. Signed-off-by: Toshi Kani <toshi.kani@hp.com> Reviewed-by: Nathan Fontenot <nfont@linux.vnet.ibm.com> Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
2013-09-25hotplug / x86: Add hotplug lock to missing placesToshi Kani1-2/+22
lock_device_hotplug[_sysfs]() serializes CPU & Memory online/offline and hotplug operations. However, this lock is not held in the debug interfaces below that initiate CPU online/offline operations. - _debug_hotplug_cpu(), cpu0 hotplug test interface enabled by CONFIG_DEBUG_HOTPLUG_CPU0. - cpu_probe_store() and cpu_release_store(), cpu hotplug test interface enabled by CONFIG_ARCH_CPU_PROBE_RELEASE. This patch changes the above interfaces to hold lock_device_hotplug(). Signed-off-by: Toshi Kani <toshi.kani@hp.com> Acked-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org> Acked-by: Yasuaki Ishimatsu <isimatu.yasuaki@jp.fujitsu.com> Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>