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e2f74f355e
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Thomas Renninger e2f74f355e [ACPI/CPUFREQ] Introduce bios_limit per cpu cpufreq sysfs interface 
This interface is mainly intended (and implemented) for ACPI _PPC BIOS
frequency limitations, but other cpufreq drivers can also use it for
similar use-cases.

Why is this needed:

Currently it's not obvious why cpufreq got limited.
People see cpufreq/scaling_max_freq reduced, but this could have
happened by:
  - any userspace prog writing to scaling_max_freq
  - thermal limitations
  - hardware (_PPC in ACPI case) limitiations

Therefore export bios_limit (in kHz) to:
  - Point the user that it's the BIOS (broken or intended) which limits
    frequency
  - Export it as a sysfs interface for userspace progs.
    While this was a rarely used feature on laptops, there will appear
    more and more server implemenations providing "Green IT" features like
    allowing the service processor to limit the frequency. People want
    to know about HW/BIOS frequency limitations.

All ACPI P-state driven cpufreq drivers are covered with this patch:
  - powernow-k8
  - powernow-k7
  - acpi-cpufreq

Tested with a patched DSDT which limits the first two cores (_PPC returns 1)
via _PPC, exposed by bios_limit:
# echo 2200000 >cpu2/cpufreq/scaling_max_freq
# cat cpu*/cpufreq/scaling_max_freq
2600000
2600000
2200000
2200000
# #scaling_max_freq shows general user/thermal/BIOS limitations

# cat cpu*/cpufreq/bios_limit
2600000
2600000
2800000
2800000
# #bios_limit only shows the HW/BIOS limitation

CC: Pallipadi Venkatesh <venkatesh.pallipadi@intel.com>
CC: Len Brown <lenb@kernel.org>
CC: davej@codemonkey.org.uk
CC: linux@dominikbrodowski.net

Signed-off-by: Thomas Renninger <trenn@suse.de>
Signed-off-by: Dave Jones <davej@redhat.com>
2009-11-24 13:33:34 -05:00
..
acpi [CPUFREQ] Enable ACPI PDC handshake for VIA/Centaur CPUs 2009-11-24 13:33:32 -05:00
apic x86, UV: Fix information in __uv_hub_info structure 2009-10-16 08:18:34 +02:00
cpu [ACPI/CPUFREQ] Introduce bios_limit per cpu cpufreq sysfs interface 2009-11-24 13:33:34 -05:00
.gitignore
alternative.c Merge branch 'x86-cpu-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/linux-2.6-tip 2009-09-14 07:57:32 -07:00
amd_iommu_init.c Merge branches 'amd-iommu/fixes' and 'dma-debug/fixes' into iommu/fixes 2009-11-03 12:05:40 +01:00
amd_iommu.c Merge branches 'amd-iommu/fixes' and 'dma-debug/fixes' into iommu/fixes 2009-11-03 12:05:40 +01:00
aperture_64.c kmemleak: Ignore the aperture memory hole on x86_64 2009-09-01 11:12:32 +01:00
apm_32.c Merge commit 'origin/x86/urgent' into x86/asm 2009-08-25 15:40:29 -07:00
asm-offsets_32.c lguest: optimize by coding restore_flags and irq_enable in assembler. 2009-06-12 22:27:03 +09:30
asm-offsets_64.c tracing: Define NR_syscalls for x86_64 2009-08-26 21:29:58 +02:00
asm-offsets.c
audit_64.c
bios_uv.c x86, UV: system table in bios accessed after unmap 2009-04-03 19:25:57 +02:00
bootflag.c
check.c x86: fix 64k corruption-check 2009-03-15 07:03:15 +01:00
cpuid.c Driver-Core: extend devnode callbacks to provide permissions 2009-09-19 12:50:38 -07:00
crash_dump_32.c x86: crash_dump: Fix non-pae kdump kernel memory accesses 2009-10-26 12:38:59 +01:00
crash_dump_64.c
crash.c x86: disable IOMMUs on kernel crash 2009-06-15 15:20:40 +02:00
doublefault_32.c x86: Use get_desc_base() 2009-07-19 18:27:51 +02:00
ds_selftest.c x86, ds: fix buffer alignment in debug store selftest 2009-04-24 10:18:51 +02:00
ds_selftest.h x86, bts: cleanups 2009-03-13 11:57:22 +01:00
ds.c x86: ds.c fix invalid assignment 2009-06-20 17:53:13 +02:00
dumpstack_32.c headers: utsname.h redux 2009-09-23 18:13:10 -07:00
dumpstack_64.c headers: utsname.h redux 2009-09-23 18:13:10 -07:00
dumpstack.c x86: Remove duplicated #include 2009-07-11 10:17:08 +02:00
dumpstack.h x86: avoid multiple declaration of kstack_depth_to_print 2009-04-14 11:45:33 +02:00
e820.c pci: increase alignment to make more space for hidden code 2009-10-11 14:43:36 -07:00
early_printk.c x86: earlyprintk: Fix regression to handle serial,ttySn as 1 arg 2009-10-01 10:34:16 +02:00
early-quirks.c x86 early quirks: eliminate unused function 2009-04-08 14:16:32 +02:00
efi_32.c
efi_64.c x86: Make 64-bit efi_ioremap use ioremap on MMIO regions 2009-08-03 13:34:25 -07:00
efi_stub_32.S Merge branch 'x86/asm' into x86/mm 2009-02-25 08:27:46 +01:00
efi_stub_64.S x86: efi_stub_32,64 - add missing ENDPROCs 2009-02-24 18:08:40 +01:00
efi.c x86: Make EFI RTC function depend on 32bit again 2009-10-27 12:35:48 +01:00
entry_32.S Merge branch 'tracing-fixes-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/linux-2.6-tip 2009-06-20 10:56:46 -07:00
entry_64.S x86: ptrace: sysret path should reach syscall_trace_leave 2009-09-22 20:33:42 -07:00
ftrace.c tracing: Convert event tracing code to use NR_syscalls 2009-08-26 21:30:02 +02:00
geode_32.c
head32.c x86: Add Moorestown early detection 2009-08-31 11:09:40 +02:00
head64.c x86: Add early platform detection 2009-08-31 11:09:40 +02:00
head_32.S Merge branch 'x86-fixes-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/linux-2.6-tip 2009-09-26 10:13:35 -07:00
head_64.S Merge branch 'x86-fixes-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/linux-2.6-tip 2009-09-26 10:13:35 -07:00
head.c
hpet.c x86: hpet: Mark per cpu interrupts IRQF_TIMER to prevent resume failure 2009-06-14 18:24:29 +02:00
i386_ksyms_32.c x86: Don't generate cmpxchg8b_emu if CONFIG_X86_CMPXCHG64=y 2009-10-01 08:42:24 +02:00
i387.c x86, math-emu: fix init_fpu for task != current 2009-03-04 20:33:16 +01:00
i8237.c
i8253.c x86: Do not unregister PIT clocksource on PIT oneshot setup/shutdown 2009-08-21 21:13:37 +02:00
i8259.c x86: refactor x86_quirks support 2009-02-23 00:08:11 +01:00
init_task.c Use new __init_task_data macro in arch init_task.c files. 2009-09-21 06:27:08 +02:00
io_delay.c x86: io_delay.c cleanup 2009-03-21 16:57:04 +05:30
ioport.c x86-32: use non-lazy io bitmap context switching 2009-03-02 12:07:48 +01:00
irq_32.c x86: Use printk_once() 2009-08-09 22:28:34 +02:00
irq_64.c
irq.c Merge branch 'linus' into x86/urgent 2009-10-15 08:07:30 +02:00
irqinit.c perf: Do the big rename: Performance Counters -> Performance Events 2009-09-21 14:28:04 +02:00
k8.c
kdebugfs.c x86: kdebugfs.c cleanup 2009-03-21 16:55:45 +05:30
kgdb.c Merge branch 'x86-asm-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/linux-2.6-tip 2009-06-10 15:49:10 -07:00
kprobes.c Merge branch 'tracing/core-v2' into tracing-for-linus 2009-04-02 00:49:02 +02:00
kvm.c KVM guest: do not batch pte updates from interrupt context 2009-09-10 18:10:50 +03:00
kvmclock.c Merge branch 'x86-platform-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/linux-2.6-tip 2009-09-18 14:05:47 -07:00
ldt.c cpumask: use mm_cpumask() wrapper: x86 2009-09-24 09:34:52 +09:30
machine_kexec_32.c x86, kexec: fix crashdump panic with CONFIG_KEXEC_JUMP 2009-05-07 22:01:05 -07:00
machine_kexec_64.c x86, kexec: fix crashdump panic with CONFIG_KEXEC_JUMP 2009-05-07 22:01:05 -07:00
Makefile Merge branch 'linus' into sfi-release 2009-09-19 00:11:26 -04:00
mca_32.c x86: refactor x86_quirks support 2009-02-23 00:08:11 +01:00
mfgpt_32.c x86: geode: Mark mfgpt irq IRQF_TIMER to prevent resume failure 2009-07-24 08:42:52 +02:00
microcode_amd.c x86, amd-ucode: Check UCODE_MAGIC before loading the container file 2009-11-10 05:46:09 +01:00
microcode_core.c mm: replace various uses of num_physpages by totalram_pages 2009-09-22 07:17:38 -07:00
microcode_intel.c x86: microcode: use smp_call_function_single instead of set_cpus_allowed, cleanup of synchronization logic 2009-05-12 10:36:44 +02:00
mmconf-fam10h_64.c x86: move various CPU initialization objects into .cpuinit.rodata 2009-03-12 13:13:07 +01:00
module.c module: cleanup FIXME comments about trimming exception table entries. 2009-06-12 21:47:05 +09:30
mpparse.c Merge branch 'x86-platform-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/linux-2.6-tip 2009-09-18 14:05:47 -07:00
mrst.c x86: Add Moorestown early detection 2009-08-31 11:09:40 +02:00
msr.c Driver-Core: extend devnode callbacks to provide permissions 2009-09-19 12:50:38 -07:00
olpc.c x86, olpc: fix model detection without OFW 2009-02-14 23:05:25 +01:00
paravirt_patch_32.c
paravirt_patch_64.c
paravirt-spinlocks.c
paravirt.c Merge branch 'x86-platform-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/linux-2.6-tip 2009-09-18 14:05:47 -07:00
pci-calgary_64.c x86: calgary: remove IOMMU_DEBUG 2009-04-14 13:03:36 +02:00
pci-dma.c x86/PCI: Adjust GFP mask handling for coherent allocations 2009-11-08 07:44:30 -08:00
pci-gart_64.c headers: remove sched.h from interrupt.h 2009-10-11 11:20:58 -07:00
pci-nommu.c dma-ops: Remove flush_write_buffers() in dma-mapping-common.h 2009-08-10 09:34:57 +02:00
pci-swiotlb.c Merge git://git.infradead.org/iommu-2.6 2009-09-23 10:06:10 -07:00
pcspeaker.c
pmtimer_64.c
probe_roms_32.c
process_32.c Merge branch 'x86-percpu-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/linux-2.6-tip 2009-09-14 08:01:28 -07:00
process_64.c x86, fs: Fix x86 procfs stack information for threads on 64-bit 2009-11-04 13:25:03 +01:00
process.c cpumask: use zalloc_cpumask_var() where possible 2009-09-24 09:34:24 +09:30
ptrace.c x86: ptrace: set TS_COMPAT when 32-bit ptrace sets orig_eax>=0 2009-09-22 22:49:24 -07:00
pvclock.c x86: Fix warning in pvclock.c 2009-07-14 16:25:05 +02:00
quirks.c x86/PCI: pci quirks, fix pci refcounting 2009-09-09 14:11:02 -07:00
reboot_fixups_32.c
reboot.c x86: Add reboot quirk for 3 series Mac mini 2009-11-02 15:46:17 +01:00
relocate_kernel_32.S x86, kexec: fix kexec x86 coding style 2009-03-10 18:13:25 -07:00
relocate_kernel_64.S x86, kexec: x86_64: add kexec jump support for x86_64 2009-03-10 18:13:25 -07:00
rtc.c Merge branch 'x86-platform-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/linux-2.6-tip 2009-09-18 14:05:47 -07:00
scx200_32.c
setup_percpu.c x86,percpu: use embedding for 64bit NUMA and page for 32bit NUMA 2009-08-14 15:00:52 +09:00
setup.c x86: Add Phoenix/MSC BIOSes to lowmem corruption list 2009-11-06 14:49:39 -08:00
sfi.c SFI: remove unneeded includes 2009-09-15 15:08:40 -04:00
signal.c Merge branch 'x86-mce-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/linux-2.6-tip 2009-09-17 21:07:08 -07:00
smp.c Revert "x86, timers: Check for pending timers after (device) interrupts" 2009-10-09 15:58:20 +02:00
smpboot.c cpumask: use zalloc_cpumask_var() where possible 2009-09-24 09:34:24 +09:30
stacktrace.c x86: add save_stack_trace_bp() for tracing from a specific stack frame 2009-06-12 23:01:05 +02:00
step.c x86: Use get_desc_base() 2009-07-19 18:27:51 +02:00
sys_i386_32.c
sys_x86_64.c tracing: Convert x86_64 mmap and uname to use DEFINE_SYSCALL 2009-08-11 20:35:29 +02:00
syscall_64.c
syscall_table_32.S perf: Do the big rename: Performance Counters -> Performance Events 2009-09-21 14:28:04 +02:00
tboot.c x86, intel_txt: clean up the impact on generic code, unbreak non-x86 2009-09-01 18:25:07 -07:00
tce_64.c
test_nx.c
test_rodata.c
time.c x86: fix kernel panic on 32 bits when profiling 2009-10-12 11:53:51 -07:00
tlb_uv.c x86, UV: Fix and clean up bau code to use uv_gpa_to_pnode() 2009-10-16 14:51:53 +02:00
tls.c
tls.h
topology.c x86: topology.c cleanup 2009-03-21 16:55:24 +05:30
trampoline_32.S x86: cpuinit-annotate SMP boot trampolines properly 2009-09-20 20:23:37 +02:00
trampoline_64.S x86: Fix Suspend to RAM freeze on Acer Aspire 1511Lmi laptop 2009-10-12 18:06:48 +02:00
trampoline.c x86: Fix Suspend to RAM freeze on Acer Aspire 1511Lmi laptop 2009-10-12 18:06:48 +02:00
traps.c Merge branch 'x86-fixes-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/linux-2.6-tip 2009-09-26 10:13:35 -07:00
tsc_sync.c x86: Reduce verbosity of "TSC is reliable" message 2009-09-24 11:35:19 +02:00
tsc.c Merge branch 'linus' into x86/urgent 2009-09-20 20:25:03 +02:00
uv_irq.c x86, apic: remove genapic.h 2009-02-17 17:52:44 +01:00
uv_sysfs.c x86: prevent /sys/firmware/sgi_uv from being created on non-uv systems 2009-04-08 14:58:10 +02:00
uv_time.c uv_time: add parameter to uv_read_rtc() 2009-04-22 17:41:25 +02:00
verify_cpu_64.S
visws_quirks.c x86: Add timer_init to x86_init_ops 2009-08-31 09:35:46 +02:00
vm86_32.c Merge branch 'x86-urgent-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/linux-2.6-tip 2009-06-10 16:15:14 -07:00
vmi_32.c x86, vmi: Mark VMI deprecated and schedule it for removal 2009-10-08 22:27:55 +02:00
vmiclock_32.c x86: Move tsc_calibration to x86_init_ops 2009-08-31 09:35:47 +02:00
vmlinux.lds.S x86: Document linker script ASSERT() quirk 2009-10-16 07:18:46 +02:00
vsmp_64.c Revert "x86: don't compile vsmp_64 for 32bit" 2009-03-25 21:34:28 +01:00
vsyscall_64.c sysctl: remove "struct file *" argument of ->proc_handler 2009-09-24 07:21:04 -07:00
x86_init.c x86: Move get/set_wallclock to x86_platform_ops 2009-09-16 14:34:50 +02:00
x8664_ksyms_64.c
xsave.c x86-64: fix FPU corruption with signals and preemption 2009-04-20 14:33:00 -07:00