linux/arch/x86
Kyung Min Park cec5f268cd x86/delay: Introduce TPAUSE delay
TPAUSE instructs the processor to enter an implementation-dependent
optimized state. The instruction execution wakes up when the time-stamp
counter reaches or exceeds the implicit EDX:EAX 64-bit input value.
The instruction execution also wakes up due to the expiration of
the operating system time-limit or by an external interrupt
or exceptions such as a debug exception or a machine check exception.

TPAUSE offers a choice of two lower power states:
 1. Light-weight power/performance optimized state C0.1
 2. Improved power/performance optimized state C0.2

This way, it can save power with low wake-up latency in comparison to
spinloop based delay. The selection between the two is governed by the
input register.

TPAUSE is available on processors with X86_FEATURE_WAITPKG.

Co-developed-by: Fenghua Yu <fenghua.yu@intel.com>
Signed-off-by: Fenghua Yu <fenghua.yu@intel.com>
Signed-off-by: Kyung Min Park <kyung.min.park@intel.com>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Reviewed-by: Tony Luck <tony.luck@intel.com>
Link: https://lkml.kernel.org/r/1587757076-30337-4-git-send-email-kyung.min.park@intel.com
2020-05-07 16:06:20 +02:00
..
boot SPDX patches for 5.7-rc1. 2020-04-03 13:12:26 -07:00
configs compiler: remove CONFIG_OPTIMIZE_INLINING entirely 2020-04-07 10:43:42 -07:00
crypto crypto: arch/nhpoly1305 - process in explicit 4k chunks 2020-04-30 15:16:59 +10:00
entry sparc,x86: vdso: remove meaningless undefining CONFIG_OPTIMIZE_INLINING 2020-04-07 10:43:42 -07:00
events perf/x86/cstate: Add Jasper Lake CPU support 2020-04-22 21:43:12 +02:00
hyperv x86/hyperv: Suspend/resume the VP assist page for hibernation 2020-04-21 10:03:19 +01:00
ia32 Merge branch 'x86-cleanups-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip 2020-03-31 11:04:05 -07:00
include x86/delay: Introduce TPAUSE delay 2020-05-07 16:06:20 +02:00
kernel x86/delay: Introduce TPAUSE delay 2020-05-07 16:06:20 +02:00
kvm KVM: s390: Fix for 5.7 and maintainer update 2020-04-21 09:37:13 -04:00
lib x86/delay: Introduce TPAUSE delay 2020-05-07 16:06:20 +02:00
math-emu
mm mm/memory_hotplug: add pgprot_t to mhp_params 2020-04-10 15:36:21 -07:00
net bpf, x86_32: Fix logic error in BPF_LDX zero-extension 2020-04-24 17:23:01 -07:00
oprofile
pci
platform efi/x86: Don't remap text<->rodata gap read-only for mixed mode 2020-04-14 08:32:17 +02:00
power
purgatory
ras
realmode SPDX patches for 5.7-rc1. 2020-04-03 13:12:26 -07:00
tools
um mm/vma: define a default value for VM_DATA_DEFAULT_FLAGS 2020-04-10 15:36:21 -07:00
video
xen xen: branch for v5.7-rc1b 2020-04-10 17:20:06 -07:00
.gitignore
Kbuild
Kconfig mm/userfaultfd: disable userfaultfd-wp on x86_32 2020-04-21 11:11:55 -07:00
Kconfig.assembler x86/delay: Introduce TPAUSE delay 2020-05-07 16:06:20 +02:00
Kconfig.cpu
Kconfig.debug
Makefile x86: probe assembler capabilities via kconfig instead of makefile 2020-04-09 00:01:59 +09:00
Makefile.um
Makefile_32.cpu