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0274f9551e
linux/arch/x86/kernel
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Grzegorz Andrejczuk 0274f9551e x86/elf: Add HWCAP2 to expose ring 3 MONITOR/MWAIT 
Introduce ELF_HWCAP2 variable for x86 and reserve its bit 0 to expose the
ring 3 MONITOR/MWAIT.

HWCAP variables contain bitmasks which can be used by userspace
applications to detect which instruction sets are supported by CPU.  On x86
architecture information about CPU capabilities can be checked via CPUID
instructions, unfortunately presence of ring 3 MONITOR/MWAIT feature cannot
be checked this way. ELF_HWCAP cannot be used as well, because on x86 it is
set to CPUID[1].EDX which means that all bits are reserved there.

HWCAP2 approach was chosen because it reuses existing solution present
in other architectures, so only minor modifications are required to the
kernel and userspace applications. When ELF_HWCAP2 is defined
kernel maps it to AT_HWCAP2 during the start of the application.
This way the ring 3 MONITOR/MWAIT feature can be detected using getauxval()
API in a simple and fast manner. ELF_HWCAP2 type is u32 to be consistent
with x86 ELF_HWCAP type.

Signed-off-by: Grzegorz Andrejczuk <grzegorz.andrejczuk@intel.com>
Cc: Piotr.Luc@intel.com
Cc: dave.hansen@linux.intel.com
Link: http://lkml.kernel.org/r/1484918557-15481-3-git-send-email-grzegorz.andrejczuk@intel.com
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
2017-02-04 08:51:09 +01:00
..
acpi x86/init: Add i8042 state to the platform data 2016-12-19 11:34:15 +01:00
apic cpu/hotplug: Cleanup state names 2016-12-25 10:47:44 +01:00
cpu x86/elf: Add HWCAP2 to expose ring 3 MONITOR/MWAIT 2017-02-04 08:51:09 +01:00
fpu x86/cpufeature: Add AVX512_VPOPCNTDQ feature 2017-01-16 20:40:53 +01:00
kprobes Replace <asm/uaccess.h> with <linux/uaccess.h> globally 2016-12-24 11:46:01 -08:00
.gitignore
alternative.c x86/alternatives: Do not use sync_core() to serialize I$ 2016-12-20 09:36:42 +01:00
amd_gart_64.c dma-mapping: use unsigned long for dma_attrs 2016-08-04 08:50:07 -04:00
amd_nb.c x86/amd_nb: Add SMN and Indirect Data Fabric access for AMD Fam17h 2016-11-16 20:46:38 +01:00
apb_timer.c Merge branch 'timers-urgent-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip 2016-12-25 14:30:04 -08:00
aperture_64.c param: convert some "on"/"off" users to strtobool 2016-03-17 15:09:34 -07:00
apm_32.c Replace <asm/uaccess.h> with <linux/uaccess.h> globally 2016-12-24 11:46:01 -08:00
asm-offsets_32.c sched/x86: Rewrite the switch_to() code 2016-08-24 12:31:41 +02:00
asm-offsets_64.c sched/x86: Rewrite the switch_to() code 2016-08-24 12:31:41 +02:00
asm-offsets.c x86: Move thread_info into task_struct 2016-09-15 08:25:13 +02:00
audit_64.c
bootflag.c
check.c
cpuid.c Merge branch 'smp-hotplug-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip 2016-12-12 19:25:04 -08:00
crash_dump_32.c Replace <asm/uaccess.h> with <linux/uaccess.h> globally 2016-12-24 11:46:01 -08:00
crash_dump_64.c
crash.c kexec_file: Change kexec_add_buffer to take kexec_buf as argument. 2016-11-30 23:14:59 +11:00
devicetree.c x86/cpufeature: Replace cpu_has_apic with boot_cpu_has() usage 2016-04-13 11:37:41 +02:00
doublefault.c Replace <asm/uaccess.h> with <linux/uaccess.h> globally 2016-12-24 11:46:01 -08:00
dumpstack_32.c x86/dumpstack: Make stack name tags more comprehensible 2016-11-21 13:00:42 +01:00
dumpstack_64.c x86/dumpstack: Make stack name tags more comprehensible 2016-11-21 13:00:42 +01:00
dumpstack.c Merge branch 'x86-asm-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip 2016-12-12 13:49:57 -08:00
e820.c x86/e820: Don't merge consecutive E820_PRAM ranges 2016-10-16 11:16:48 +02:00
early_printk.c x86: Fix misspellings in comments 2016-02-24 08:44:58 +01:00
early-quirks.c Merge tag 'drm-for-v4.9' of git://people.freedesktop.org/~airlied/linux 2016-10-11 18:12:22 -07:00
ebda.c x86/boot: Simplify EBDA-vs-BIOS reservation logic 2016-07-22 11:46:01 +02:00
espfix_64.c x86: get rid of superfluous __GFP_REPEAT 2016-06-24 17:23:52 -07:00
ftrace.c ftrace/x86: Implement HAVE_FUNCTION_GRAPH_RET_ADDR_PTR 2016-08-24 12:15:15 +02:00
head32.c x86/boot: Run reserve_bios_regions() after we initialize the memory map 2016-08-11 11:14:59 +02:00
head64.c x86/boot: Run reserve_bios_regions() after we initialize the memory map 2016-08-11 11:14:59 +02:00
head_32.S Merge branch 'x86-asm-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip 2016-12-12 13:49:57 -08:00
head_64.S x86/boot/64: Push correct start_cpu() return address 2016-12-14 08:48:05 +01:00
hpet.c Merge branch 'timers-urgent-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip 2016-12-25 14:30:04 -08:00
hw_breakpoint.c x86/kernel: Audit and remove any unnecessary uses of module.h 2016-07-14 15:06:41 +02:00
i8237.c
i8253.c x86/kernel: Audit and remove any unnecessary uses of module.h 2016-07-14 15:06:41 +02:00
i8259.c x86/irq: Probe for PIC presence before allocating descs for legacy IRQs 2015-11-07 10:37:37 +01:00
io_delay.c x86/kernel: Audit and remove any unnecessary uses of module.h 2016-07-14 15:06:41 +02:00
ioport.c x86/iopl: Fix iopl capability check on Xen PV 2016-03-17 09:49:27 +01:00
irq_32.c x86/kernel: Audit and remove any unnecessary uses of module.h 2016-07-14 15:06:41 +02:00
irq_64.c x86: Remove empty idle.h header 2016-12-09 21:23:22 +01:00
irq_work.c treewide: Remove old email address 2015-11-23 09:44:58 +01:00
irq.c x86: Remove empty idle.h header 2016-12-09 21:23:22 +01:00
irqinit.c
itmt.c x86/sched: Use #include <linux/mutex.h> instead of #include <asm/mutex.h> 2016-11-28 09:43:49 +01:00
jump_label.c x86/asm: Stop depending on ptrace.h in alternative.h 2016-04-29 11:56:40 +02:00
kdebugfs.c x86/kernel: Audit and remove any unnecessary uses of module.h 2016-07-14 15:06:41 +02:00
kexec-bzimage64.c kexec_file: Change kexec_add_buffer to take kexec_buf as argument. 2016-11-30 23:14:59 +11:00
kgdb.c sched/x86: Add 'struct inactive_task_frame' to better document the sleeping task stack frame 2016-08-24 12:27:41 +02:00
ksysfs.c x86: Apply more __ro_after_init and const 2016-08-10 14:55:05 +02:00
kvm.c Merge branch 'x86-idle-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip 2016-12-12 14:55:04 -08:00
kvmclock.c clocksource: Use a plain u64 instead of cycle_t 2016-12-25 11:04:12 +01:00
ldt.c Merge branch 'akpm' (patches from Andrew) 2016-12-12 20:50:02 -08:00
livepatch.c livepatch/x86: apply alternatives and paravirt patches after relocations 2016-08-18 23:41:55 +02:00
machine_kexec_32.c
machine_kexec_64.c kexec: export the value of phys_base instead of symbol address 2016-12-14 16:04:07 -08:00
Makefile Merge branch 'x86-timers-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip 2016-12-18 13:59:10 -08:00
mcount_64.S x86: Fix export for mcount and __fentry__ 2016-10-26 12:38:17 +02:00
mmconf-fam10h_64.c
module.c x86/asm: Stop depending on ptrace.h in alternative.h 2016-04-29 11:56:40 +02:00
mpparse.c x86/mm/numa: Open code function early_get_boot_cpu_id() 2016-08-15 08:51:54 +02:00
msr.c x86/msr: Remove bogus cleanup from the error path 2016-12-25 10:47:41 +01:00
nmi_selftest.c
nmi.c x86: include linux/ratelimit.h in nmi.c 2016-06-06 17:10:15 +02:00
paravirt_patch_32.c x86/paravirt: Mark unused patch_default label 2016-12-22 17:43:35 +01:00
paravirt_patch_64.c x86/paravirt: Mark unused patch_default label 2016-12-22 17:43:35 +01:00
paravirt-spinlocks.c x86/paravirt: Optimize native pv_lock_ops.vcpu_is_preempted() 2016-11-22 12:48:11 +01:00
paravirt.c x86/fpu: Remove clts() 2016-11-01 07:47:55 +01:00
pci-calgary_64.c dma-mapping: use unsigned long for dma_attrs 2016-08-04 08:50:07 -04:00
pci-dma.c dma-mapping: use unsigned long for dma_attrs 2016-08-04 08:50:07 -04:00
pci-iommu_table.c x86: Fix non-static inlines 2016-04-16 13:21:40 +02:00
pci-nommu.c dma-mapping: use unsigned long for dma_attrs 2016-08-04 08:50:07 -04:00
pci-swiotlb.c swiotlb: Convert swiotlb_force from int to enum 2016-12-19 09:05:20 -05:00
pcspeaker.c
perf_regs.c
platform-quirks.c x86/init: Add i8042 state to the platform data 2016-12-19 11:34:15 +01:00
pmem.c x86/kernel: Audit and remove any unnecessary uses of module.h 2016-07-14 15:06:41 +02:00
probe_roms.c
process_32.c Merge branch 'x86-cache-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip 2016-12-22 09:25:45 -08:00
process_64.c Merge branch 'x86-cache-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip 2016-12-22 09:25:45 -08:00
process.c Replace <asm/uaccess.h> with <linux/uaccess.h> globally 2016-12-24 11:46:01 -08:00
ptrace.c Replace <asm/uaccess.h> with <linux/uaccess.h> globally 2016-12-24 11:46:01 -08:00
pvclock.c clocksource: Use a plain u64 instead of cycle_t 2016-12-25 11:04:12 +01:00
quirks.c x86/quirks: Hide maybe-uninitialized warning 2016-10-25 11:45:13 +02:00
reboot_fixups_32.c
reboot.c x86: Apply more __ro_after_init and const 2016-08-10 14:55:05 +02:00
relocate_kernel_32.S
relocate_kernel_64.S
resource.c x86/e820: Prepare e280 code for switch to dynamic storage 2016-09-21 15:02:12 +02:00
rtc.c timekeeping: Ignore the bogus sleep time if pm_trace is enabled 2016-11-29 18:02:58 +01:00
setup_percpu.c x86/percpu: Remove unnecessary include of module.h, add asm/desc.h 2016-11-15 07:26:37 +01:00
setup.c mm: remove x86-only restriction of movable_node 2016-12-12 18:55:07 -08:00
signal_compat.c x86/signal: Remove bogus user_64bit_mode() check from sigaction_compat_abi() 2016-10-20 13:05:15 +02:00
signal.c Merge branch 'x86-vdso-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip 2016-10-03 17:29:01 -07:00
smp.c x86/apic: Prevent tracing on apic_msr_write_eoi() 2016-11-09 22:03:14 +01:00
smpboot.c x86/smpboot: Prevent false positive out of bounds cpumask access warning 2016-12-15 11:32:31 +01:00
stacktrace.c x86/stacktrace: Convert save_stack_trace_*() to use the new unwinder 2016-09-20 08:29:33 +02:00
step.c mm: replace access_process_vm() write parameter with gup_flags 2016-10-19 08:31:25 -07:00
sys_x86_64.c x86: use simpler API for random address requests 2016-10-11 15:06:32 -07:00
sysfb_efi.c Merge branch 'linus' into efi/core, to pick up fixes 2016-05-07 07:00:07 +02:00
sysfb_simplefb.c x86/sysfb: Fix lfb_size calculation 2016-11-16 09:38:23 +01:00
sysfb.c
tboot.c cpu/hotplug: Cleanup state names 2016-12-25 10:47:44 +01:00
tce_64.c x86/cpufeature: Remove cpu_has_clflush 2016-03-31 13:35:09 +02:00
test_nx.c Replace <asm/uaccess.h> with <linux/uaccess.h> globally 2016-12-24 11:46:01 -08:00
test_rodata.c x86: Don't use module.h just for AUTHOR / LICENSE tags 2016-07-14 13:04:20 +02:00
time.c
tls.c Replace <asm/uaccess.h> with <linux/uaccess.h> globally 2016-12-24 11:46:01 -08:00
tls.h
topology.c
trace_clock.c
tracepoint.c tracing: Have the reg function allow to fail 2016-12-09 09:13:30 -05:00
traps.c x86/fpu: Handle #NM without FPU emulation as an error 2016-11-01 07:47:54 +01:00
tsc_msr.c x86/tsc: Set TSC_KNOWN_FREQ and TSC_RELIABLE flags on Intel Atom SoCs 2016-11-18 10:58:31 +01:00
tsc_sync.c x86/tsc: Limit the adjust value further 2016-12-18 16:37:04 +01:00
tsc.c x86/tsc: Add the Intel Denverton Processor to native_calibrate_tsc() 2017-01-14 09:30:37 +01:00
unwind_frame.c x86/unwind: Disable KASAN checks for non-current tasks 2017-01-12 09:28:27 +01:00
unwind_guess.c x86/unwind: Fix guess-unwinder regression 2016-11-28 07:47:54 +01:00
uprobes.c uprobes/x86: Fix RIP-relative handling of EVEX-encoded instructions 2016-08-12 08:29:24 +02:00
verify_cpu.S x86/cpufeature: Carve out X86_FEATURE_* 2016-01-30 11:22:17 +01:00
vm86_32.c Replace <asm/uaccess.h> with <linux/uaccess.h> globally 2016-12-24 11:46:01 -08:00
vmlinux.lds.S x86/boot: Move the _stext marker to before the boot code 2016-10-20 09:15:24 +02:00
vsmp_64.c
x86_init.c x86/init: Remove i8042_detect() from platform ops 2016-12-19 11:34:15 +01:00