Commit Graph

1237 Commits

Author SHA1 Message Date
Linus Torvalds b3345d7c57 ARM: SoC platform changes for 3.17
This is the bulk of new SoC enablement and other platform changes for 3.17:
 
 * Samsung S5PV210 has been converted to DT and multiplatform
 * Clock drivers and bindings for some of the lower-end i.MX 1/2 platforms
 * Kirkwood, one of the popular Marvell platforms, is folded into the
   mvebu platform code, removing mach-kirkwood.
 * Hwmod data for TI AM43xx and DRA7 platforms.
 * More additions of Renesas shmobile platform support
 * Removal of plat-samsung contents that can be removed with S5PV210 being
   multiplatform/DT-enabled and the other two old platforms being removed.
 
 New platforms (most with only basic support right now):
 
 * Hisilicon X5HD2 settop box chipset is introduced
 * Mediatek MT6589 (mobile chipset) is introduced
 * Broadcom BCM7xxx settop box chipset is introduced
 
 + as usual a lot other pieces all over the platform code.
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Merge tag 'soc-for-3.17' of git://git.kernel.org/pub/scm/linux/kernel/git/arm/arm-soc

Pull ARM SoC platform changes from Olof Johansson:
 "This is the bulk of new SoC enablement and other platform changes for
  3.17:

   - Samsung S5PV210 has been converted to DT and multiplatform
   - Clock drivers and bindings for some of the lower-end i.MX 1/2
     platforms
   - Kirkwood, one of the popular Marvell platforms, is folded into the
     mvebu platform code, removing mach-kirkwood
   - Hwmod data for TI AM43xx and DRA7 platforms
   - More additions of Renesas shmobile platform support
   - Removal of plat-samsung contents that can be removed with S5PV210
     being multiplatform/DT-enabled and the other two old platforms
     being removed

  New platforms (most with only basic support right now):

   - Hisilicon X5HD2 settop box chipset is introduced
   - Mediatek MT6589 (mobile chipset) is introduced
   - Broadcom BCM7xxx settop box chipset is introduced

  + as usual a lot other pieces all over the platform code"

* tag 'soc-for-3.17' of git://git.kernel.org/pub/scm/linux/kernel/git/arm/arm-soc: (240 commits)
  ARM: hisi: remove smp from machine descriptor
  power: reset: move hisilicon reboot code
  ARM: dts: Add hix5hd2-dkb dts file.
  ARM: debug: Rename Hi3716 to HIX5HD2
  ARM: hisi: enable hix5hd2 SoC
  ARM: hisi: add ARCH_HISI
  MAINTAINERS: add entry for Broadcom ARM STB architecture
  ARM: brcmstb: select GISB arbiter and interrupt drivers
  ARM: brcmstb: add infrastructure for ARM-based Broadcom STB SoCs
  ARM: configs: enable SMP in bcm_defconfig
  ARM: add SMP support for Broadcom mobile SoCs
  Documentation: arm: misc updates to Marvell EBU SoC status
  Documentation: arm: add URLs to public datasheets for the Marvell Armada XP SoC
  ARM: mvebu: fix build without platforms selected
  ARM: mvebu: add cpuidle support for Armada 38x
  ARM: mvebu: add cpuidle support for Armada 370
  cpuidle: mvebu: add Armada 38x support
  cpuidle: mvebu: add Armada 370 support
  cpuidle: mvebu: rename the driver from armada-370-xp to mvebu-v7
  ARM: mvebu: export the SCU address
  ...
2014-08-08 11:14:29 -07:00
Linus Torvalds f536b3cae8 Merge branch 'next' of git://git.kernel.org/pub/scm/linux/kernel/git/benh/powerpc
Pull powerpc updates from Ben Herrenschmidt:
 "This is the powerpc new goodies for 3.17.  The short story:

  The biggest bit is Michael removing all of pre-POWER4 processor
  support from the 64-bit kernel.  POWER3 and rs64.  This gets rid of a
  ton of old cruft that has been bitrotting in a long while.  It was
  broken for quite a few versions already and nobody noticed.  Nobody
  uses those machines anymore.  While at it, he cleaned up a bunch of
  old dusty cabinets, getting rid of a skeletton or two.

  Then, we have some base VFIO support for KVM, which allows assigning
  of PCI devices to KVM guests, support for large 64-bit BARs on
  "powernv" platforms, support for HMI (Hardware Management Interrupts)
  on those same platforms, some sparse-vmemmap improvements (for memory
  hotplug),

  There is the usual batch of Freescale embedded updates (summary in the
  merge commit) and fixes here or there, I think that's it for the
  highlights"

* 'next' of git://git.kernel.org/pub/scm/linux/kernel/git/benh/powerpc: (102 commits)
  powerpc/eeh: Export eeh_iommu_group_to_pe()
  powerpc/eeh: Add missing #ifdef CONFIG_IOMMU_API
  powerpc: Reduce scariness of interrupt frames in stack traces
  powerpc: start loop at section start of start in vmemmap_populated()
  powerpc: implement vmemmap_free()
  powerpc: implement vmemmap_remove_mapping() for BOOK3S
  powerpc: implement vmemmap_list_free()
  powerpc: Fail remap_4k_pfn() if PFN doesn't fit inside PTE
  powerpc/book3s: Fix endianess issue for HMI handling on napping cpus.
  powerpc/book3s: handle HMIs for cpus in nap mode.
  powerpc/powernv: Invoke opal call to handle hmi.
  powerpc/book3s: Add basic infrastructure to handle HMI in Linux.
  powerpc/iommu: Fix comments with it_page_shift
  powerpc/powernv: Handle compound PE in config accessors
  powerpc/powernv: Handle compound PE for EEH
  powerpc/powernv: Handle compound PE
  powerpc/powernv: Split ioda_eeh_get_state()
  powerpc/powernv: Allow to freeze PE
  powerpc/powernv: Enable M64 aperatus for PHB3
  powerpc/eeh: Aux PE data for error log
  ...
2014-08-07 08:50:34 -07:00
Linus Torvalds e669830526 Merge branch 'upstream' of git://git.linux-mips.org/pub/scm/ralf/upstream-linus
Pull MIPS updates from Ralf Baechle:
 "This is the main pull request for 3.17.  It contains:

   - misc Cavium Octeon, BCM47xx, BCM63xx and Alchemy  updates
   - MIPS ptrace updates and cleanups
   - various fixes that will also go to -stable
   - a number of cleanups and small non-critical fixes.
   - NUMA support for the Loongson 3.
   - more support for MSA
   - support for MAAR
   - various FP enhancements and fixes"

* 'upstream' of git://git.linux-mips.org/pub/scm/ralf/upstream-linus: (139 commits)
  MIPS: jz4740: remove unnecessary null test before debugfs_remove
  MIPS: Octeon: remove unnecessary null test before debugfs_remove_recursive
  MIPS: ZBOOT: implement stack protector in compressed boot phase
  MIPS: mipsreg: remove duplicate MIPS_CONF4_FTLBSETS_SHIFT
  MIPS: Bonito64: remove a duplicate define
  MIPS: Malta: initialise MAARs
  MIPS: Initialise MAARs
  MIPS: detect presence of MAARs
  MIPS: define MAAR register accessors & bits
  MIPS: mark MSA experimental
  MIPS: Don't build MSA support unless it can be used
  MIPS: consistently clear MSA flags when starting & copying threads
  MIPS: 16 byte align MSA vector context
  MIPS: disable preemption whilst initialising MSA
  MIPS: ensure MSA gets disabled during boot
  MIPS: fix read_msa_* & write_msa_* functions on non-MSA toolchains
  MIPS: fix MSA context for tasks which don't use FP first
  MIPS: init upper 64b of vector registers when MSA is first used
  MIPS: save/disable MSA in lose_fpu
  MIPS: preserve scalar FP CSR when switching vector context
  ...
2014-08-07 08:47:00 -07:00
Vaidyanathan Srinivasan 6174bac8c7 powerpc/cpufreq: Add pr_warn() on OPAL firmware failures
Cpufreq depends on platform firmware to implement PStates.  In case of
platform firmware failure, cpufreq should not panic host kernel with
BUG_ON().  Less severe pr_warn() will suffice.

Add firmware_has_feature(FW_FEATURE_OPALv3) check to
skip probing for device-tree on non-powernv platforms.

Signed-off-by: Vaidyanathan Srinivasan <svaidy@linux.vnet.ibm.com>
Acked-by: Gautham R. Shenoy <ego@linux.vnet.ibm.com>
CC: <stable@vger.kernel.org>
Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
2014-08-05 15:40:41 +10:00
Huacai Chen 140e39c1e3 MIPS: Loongson: Modify ChipConfig register definition
This patch is prepared for Multi-chip interconnection. Since each chip
has a ChipConfig register, LOONGSON_CHIPCFG should be an array.

Signed-off-by: Huacai Chen <chenhc@lemote.com>
Cc: John Crispin <john@phrozen.org>
Cc: Steven J. Hill <Steven.Hill@imgtec.com>
Cc: Aurelien Jarno <aurelien@aurel32.net>
Cc: linux-mips@linux-mips.org
Cc: Fuxin Zhang <zhangfx@lemote.com>
Cc: Zhangjin Wu <wuzhangjin@gmail.com>
Patchwork: https://patchwork.linux-mips.org/patch/7185/
Signed-off-by: Ralf Baechle <ralf@linux-mips.org>
2014-07-30 21:46:00 +02:00
Arnd Bergmann 96bda115ec Samsung S5PV210 DT support for v3.17
- support common clock framework for s5pv210 clock
 - add generic PHY driver on s5pv210 to support it via DT
 - add dt support for s5pv210-goni, smdkc110, smdkv210 and torbreck boards
 - remove board files from mach-s5pv210 and unused codes
 - enable multiplatform for s5pv210
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Merge tag 's5pv210-dt' of git://git.kernel.org/pub/scm/linux/kernel/git/kgene/linux-samsung into next/soc

Merge "Samsung S5PV210 DT support for v3.17" from Kukjin Kim:

- support common clock framework for s5pv210 clock
- add generic PHY driver on s5pv210 to support it via DT
- add dt support for s5pv210-goni, smdkc110, smdkv210 and torbreck boards
- remove board files from mach-s5pv210 and unused codes
- enable multiplatform for s5pv210

* tag 's5pv210-dt' of git://git.kernel.org/pub/scm/linux/kernel/git/kgene/linux-samsung:
  clk: samsung: s5pv210: Remove legacy board support
  ARM: SAMSUNG: Remove remaining legacy code
  gpio: samsung: Remove legacy support of S5PV210
  ARM: S5PV210: Enable multi-platform build support
  cpufreq: s5pv210: Make the driver multiplatform aware
  ARM: S5PV210: Register cpufreq platform device
  ARM: S5PV210: move debug-macro.S into the common space
  ARM: S5PV210: Untie PM support from legacy code
  ARM: S5PV210: Remove support for board files
  ARM: dts: Add Device tree for s5pc110/s5pv210 boards
  ARM: dts: Add Device tree for s5pv210 SoC
  ARM: S5PV210: Add board file for boot using Device Tree
  phy: Add support for S5PV210 to the Exynos USB 2.0 PHY driver
  clk: samsung: Add S5PV210 Audio Subsystem clock driver
  ARM: SAMSUNG: Remove legacy clock code
  serial: samsung: Remove support for legacy clock code
  cpufreq: s3c24xx: Remove some dead code
  ARM: S5PV210: Migrate clock handling to Common Clock Framework
  clk: samsung: Add clock driver for S5PV210 and compatible SoCs

Signed-off-by: Arnd Bergmann <arnd@arndb.de>
2014-07-26 12:01:27 +02:00
Viresh Kumar 1bfb425b3b cpufreq: move policy kobj to update_policy_cpu()
We are calling kobject_move() from two separate places currently and both these
places share another routine update_policy_cpu() which is handling everything
around updating policy->cpu. Moving ownership of policy->kobj also lies under
the role of update_policy_cpu() routine and must be handled from there.

So, Lets move kobject_move() to update_policy_cpu() and get rid of
cpufreq_nominate_new_policy_cpu() as it doesn't have anything significant left.

Signed-off-by: Viresh Kumar <viresh.kumar@linaro.org>
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
2014-07-21 13:43:20 +02:00
Viresh Kumar 41dfd908fc cpufreq: propagate error returned by kobject_move()
We are returning -EINVAL instead of the error returned from kobject_move() when
it fails. Propagate the actual error number.

Also add a meaningful print when sysfs_create_link() fails.

Signed-off-by: Viresh Kumar <viresh.kumar@linaro.org>
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
2014-07-21 13:43:20 +02:00
Viresh Kumar 1461dc7d1c cpufreq: don't restore policy->cpus on failure to move kobj
While hot-unplugging policy->cpu, we call cpufreq_nominate_new_policy_cpu() to
nominate next owner of policy, i.e. policy->cpu. If we fail to move policy
kobject under the new policy->cpu, we try to update policy->cpus with the old
policy->cpu.

This would have been required in case old-CPU is removed from policy->cpus in
the first place. But its not done before calling
cpufreq_nominate_new_policy_cpu(), but during the POST_DEAD notification which
happens quite late in the hot-unplugging path.

So, this is just some useless code hanging around, get rid of it.

Signed-off-by: Viresh Kumar <viresh.kumar@linaro.org>
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
2014-07-21 13:43:20 +02:00
Mikulas Patocka 853aa05aad powernow-k6: support 350MHz CPU
There exists 350MHz K6-2E+ CPU, so add it to the usual frequency table.

Signed-off-by: Mikulas Patocka <mpatocka@redhat.com>
Acked-by: Viresh Kumar <viresh.kumar@linaro.org>
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
2014-07-21 13:43:19 +02:00
Stratos Karafotis 6393d6a102 cpufreq: ondemand: Eliminate the deadband effect
Currently, ondemand calculates the target frequency proportional to load
using the formula:
	Target frequency = C * load
	where C = policy->cpuinfo.max_freq / 100

Though, in many cases, the minimum available frequency is pretty high and
the above calculation introduces a dead band from load 0 to
100 * policy->cpuinfo.min_freq / policy->cpuinfo.max_freq where the target
frequency is always calculated to less than policy->cpuinfo.min_freq and
the minimum frequency is selected.

For example: on Intel i7-3770 @ 3.4GHz the policy->cpuinfo.min_freq = 1600000
and the policy->cpuinfo.max_freq = 3400000 (without turbo). Thus, the CPU
starts to scale up at a load above 47.
On quad core 1500MHz Krait the policy->cpuinfo.min_freq = 384000
and the policy->cpuinfo.max_freq = 1512000. Thus, the CPU starts to scale
at load above 25.

Change the calculation of target frequency to eliminate the above effect using
the formula:

	Target frequency = A + B * load
	where A = policy->cpuinfo.min_freq and
	      B = (policy->cpuinfo.max_freq - policy->cpuinfo->min_freq) / 100

This will map load values 0 to 100 linearly to cpuinfo.min_freq to
cpuinfo.max_freq.

Also, use the CPUFREQ_RELATION_C in __cpufreq_driver_target to select the
closest frequency in frequency_table. This is necessary to avoid selection
of minimum frequency only when load equals to 0. It will also help for selection
of frequencies using a more 'fair' criterion.

Tables below show the difference in selected frequency for specific values
of load without and with this patch. On Intel i7-3770 @ 3.40GHz:
	Without			With
Load	Target	Selected	Target	Selected
0	0	1600000		1600000	1600000
5	170050	1600000		1690050	1700000
10	340100	1600000		1780100	1700000
15	510150	1600000		1870150	1900000
20	680200	1600000		1960200	2000000
25	850250	1600000		2050250	2100000
30	1020300	1600000		2140300	2100000
35	1190350	1600000		2230350	2200000
40	1360400	1600000		2320400	2400000
45	1530450	1600000		2410450	2400000
50	1700500	1900000		2500500	2500000
55	1870550	1900000		2590550	2600000
60	2040600	2100000		2680600	2600000
65	2210650	2400000		2770650	2800000
70	2380700	2400000		2860700	2800000
75	2550750	2600000		2950750	3000000
80	2720800	2800000		3040800	3000000
85	2890850	2900000		3130850	3100000
90	3060900	3100000		3220900	3300000
95	3230950	3300000		3310950	3300000
100	3401000	3401000		3401000	3401000

On ARM quad core 1500MHz Krait:
	Without			With
Load	Target	Selected	Target	Selected
0	0	384000		384000	384000
5	75600	384000		440400	486000
10	151200	384000		496800	486000
15	226800	384000		553200	594000
20	302400	384000		609600	594000
25	378000	384000		666000	702000
30	453600	486000		722400	702000
35	529200	594000		778800	810000
40	604800	702000		835200	810000
45	680400	702000		891600	918000
50	756000	810000		948000	918000
55	831600	918000		1004400	1026000
60	907200	918000		1060800	1026000
65	982800	1026000		1117200	1134000
70	1058400	1134000		1173600	1134000
75	1134000	1134000		1230000	1242000
80	1209600	1242000		1286400	1242000
85	1285200	1350000		1342800	1350000
90	1360800	1458000		1399200	1350000
95	1436400	1458000		1455600	1458000
100	1512000	1512000		1512000	1512000

Tested on Intel i7-3770 CPU @ 3.40GHz and on ARM quad core 1500MHz Krait
(Android smartphone).
Benchmarks on Intel i7 shows a performance improvement on low and medium
work loads with lower power consumption. Specifics:

Phoronix Linux Kernel Compilation 3.1:
Time: -0.40%, energy: -0.07%
Phoronix Apache:
Time: -4.98%, energy: -2.35%
Phoronix FFMPEG:
Time: -6.29%, energy: -4.02%

Also, running mp3 decoding (very low load) shows no differences with and
without this patch.

Signed-off-by: Stratos Karafotis <stratosk@semaphore.gr>
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
2014-07-21 13:43:19 +02:00
Stratos Karafotis 5b0c0b16d4 cpufreq: Introduce new relation for freq selection
Introduce CPUFREQ_RELATION_C for frequency selection.
It selects the frequency with the minimum euclidean distance to target.
In case of equal distance between 2 frequencies, it will select the
greater frequency.

Signed-off-by: Stratos Karafotis <stratosk@semaphore.gr>
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
2014-07-21 13:43:19 +02:00
Anson Huang 22d0628a22 cpufreq: imx6: remove pu regulator dependency for SOCs with no PU regulator
PU regulator is not a necessary regulator for cpufreq, not all
i.MX6 SoCs have PU regulator, only if SOC has PU regulator, then its
voltage must be equal to SOC regulator, so remove the dependency
to support i.MX6SX which has no PU regulator.

Signed-off-by: Anson Huang <b20788@freescale.com>
Acked-by: Viresh Kumar <viresh.kumar@linaro.org>
Acked-by: Shawn Guo <shawn.guo@freescale.com>
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
2014-07-21 13:43:19 +02:00
Stratos Karafotis 78e2708691 cpufreq: intel_pstate: Remove core_pct rounding
The specific rounding adds conditionally only 1/256 to fractional
part of core_pct.

We can safely remove it without any noticeable impact in
calculations.

Use div64_u64 instead of div_u64 to avoid possible overflow of
sample->mperf as divisor

Signed-off-by: Stratos Karafotis <stratosk@semaphore.gr>
Signed-off-by: Dirk Brandewie <dirk.j.brandewie@intel.com>
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
2014-07-21 13:43:19 +02:00
Stratos Karafotis 4b707c893d cpufreq: intel_pstate: Simplify P state adjustment logic.
Simplify the code by removing the inline functions pstate_increase and
pstate_decrease and use directly the intel_pstate_set_pstate.

Signed-off-by: Stratos Karafotis <stratosk@semaphore.gr>
Acked-by: Dirk Brandewie <dirk.j.brandewie@intel.com>
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
2014-07-21 13:43:19 +02:00
Stratos Karafotis ac658131d7 cpufreq: intel_pstate: Keep values in aperf/mperf in full precision
Currently we shift right aperf and mperf variables by FRAC_BITS
to prevent overflow when we convert them to fix point numbers
(shift left by FRAC_BITS).

But this is not necessary, because we actually use delta aperf and mperf
which are much less than APERF and MPERF values.

So, use the unmodified APERF and MPERF values in calculation.
This also adds 8 bits in precision, although the gain is insignificant.

Signed-off-by: Stratos Karafotis <stratosk@semaphore.gr>
Signed-off-by: Dirk Brandewie <dirk.j.brandewie@intel.com>
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
2014-07-21 13:43:18 +02:00
Stratos Karafotis 4ab60c3f32 cpufreq: intel_pstate: Disable interrupts during MSRs reading
According to Intel 64 and IA-32 Architectures SDM, Volume 3,
Chapter 14.2, "Software needs to exercise care to avoid delays
between the two RDMSRs (for example interrupts)".

So, disable interrupts during reading MSRs IA32_APERF and IA32_MPERF.
This should increase the accuracy of the calculations.

Signed-off-by: Stratos Karafotis <stratosk@semaphore.gr>
Signed-off-by: Dirk Brandewie <dirk.j.brandewie@intel.com>
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
2014-07-21 13:43:18 +02:00
Stratos Karafotis c410833a3c cpufreq: intel_pstate: Align multiple lines to open parenthesis
Suppress checkpatch.pl --strict warnings:
CHECK: Alignment should match open parenthesis

Signed-off-by: Stratos Karafotis <stratosk@semaphore.gr>
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
2014-07-21 13:43:18 +02:00
Stratos Karafotis abf013bffe cpufreq: intel_pstate: Remove unnecessary intermediate variable sample_time
Remove the unnecessary intermediate assignment and use directly the
pid_params.sample_rate_ms variable.

Signed-off-by: Stratos Karafotis <stratosk@semaphore.gr>
Signed-off-by: Dirk Brandewie <dirk.j.brandewie@intel.com>
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
2014-07-21 13:43:18 +02:00
Stratos Karafotis 285cb99091 cpufreq: intel_pstate: Cleanup parentheses
Remove unnecessary parentheses.
Also, add parentheses in one case for better readability.

Signed-off-by: Stratos Karafotis <stratosk@semaphore.gr>
Signed-off-by: Dirk Brandewie <dirk.j.brandewie@intel.com>
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
2014-07-21 13:43:18 +02:00
Stratos Karafotis 2d8d1f18ed cpufreq: intel_pstate: Fit code in a single line where possible
We can fit these lines in a single one, under the 80 characters
limit.

Signed-off-by: Stratos Karafotis <stratosk@semaphore.gr>
Signed-off-by: Dirk Brandewie <dirk.j.brandewie@intel.com>
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
2014-07-21 13:43:18 +02:00
Stratos Karafotis 845c1cbef0 cpufreq: intel_pstate: Add missing blank lines after declarations
Also, remove unnecessary blank lines.

Signed-off-by: Stratos Karafotis <stratosk@semaphore.gr>
Signed-off-by: Dirk Brandewie <dirk.j.brandewie@intel.com>
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
2014-07-21 13:43:18 +02:00
Stratos Karafotis fa30dff9a8 cpufreq: intel_pstate: Remove unnecessary type casting in div_s64() call
div_s64() accepts the divisor parameter as s32. Helper div_fp()
also accepts divisor as int32_t.

So, remove the unnecessary int64_t type casting.

Signed-off-by: Stratos Karafotis <stratosk@semaphore.gr>
Signed-off-by: Dirk Brandewie <dirk.j.brandewie@intel.com>
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
2014-07-21 13:43:17 +02:00
Stratos Karafotis 317dd50e80 cpufreq: intel_pstate: Make intel_pstate_kobject and debugfs_parent locals
Since we never remove sysfs entry and debugfs files, we can make
the intel_pstate_kobject and debugfs_parent locals.

Also, annotate with __init intel_pstate_sysfs_expose_params()
and intel_pstate_debug_expose_params() in order to be freed
after bootstrap.

Signed-off-by: Stratos Karafotis <stratosk@semaphore.gr>
Signed-off-by: Dirk Brandewie <dirk.j.brandewie@intel.com>
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
2014-07-21 13:43:17 +02:00
Tomasz Figa 6d4ed0f46a cpufreq: s5pv210: Make the driver multiplatform aware
Signed-off-by: Tomasz Figa <t.figa@samsung.com>
Signed-off-by: Kukjin Kim <kgene.kim@samsung.com>
2014-07-19 04:32:15 +09:00
Tomasz Figa 56e9e367ee cpufreq: s3c24xx: Remove some dead code
There is no use for the .resume_clocks() callback now and in fact all
the provided functions are empty, so this patch just removes it in
preparation for further patches.

Reported-by: Arnd Bergmann <arnd@arndb.de>
Signed-off-by: Tomasz Figa <t.figa@samsung.com>
Signed-off-by: Kukjin Kim <kgene.kim@samsung.com>
2014-07-19 04:24:59 +09:00
Viresh Kumar 92c14bd947 cpufreq: move policy kobj to policy->cpu at resume
This is only relevant to implementations with multiple clusters, where clusters
have separate clock lines but all CPUs within a cluster share it.

Consider a dual cluster platform with 2 cores per cluster. During suspend we
start hot unplugging CPUs in order 1 to 3. When CPU2 is removed, policy->kobj
would be moved to CPU3 and when CPU3 goes down we wouldn't free policy or its
kobj as we want to retain permissions/values/etc.

Now on resume, we will get CPU2 before CPU3 and will call __cpufreq_add_dev().
We will recover the old policy and update policy->cpu from 3 to 2 from
update_policy_cpu().

But the kobj is still tied to CPU3 and isn't moved to CPU2. We wouldn't create a
link for CPU2, but would try that for CPU3 while bringing it online. Which will
report errors as CPU3 already has kobj assigned to it.

This bug got introduced with commit 42f921a, which overlooked this scenario.

To fix this, lets move kobj to the new policy->cpu while bringing first CPU of a
cluster back. Also do a WARN_ON() if kobject_move failed, as we would reach here
only for the first CPU of a non-boot cluster. And we can't recover from this
situation, if kobject_move() fails.

Fixes: 42f921a6f1 (cpufreq: remove sysfs files for CPUs which failed to come back after resume)
Cc:  3.13+ <stable@vger.kernel.org> # 3.13+
Reported-and-tested-by: Bu Yitian <ybu@qti.qualcomm.com>
Reported-by: Saravana Kannan <skannan@codeaurora.org>
Reviewed-by: Srivatsa S. Bhat <srivatsa@mit.edu>
Signed-off-by: Viresh Kumar <viresh.kumar@linaro.org>
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
2014-07-17 14:23:22 +02:00
Viresh Kumar 1bf8cc3d01 cpufreq: cpu0: OPPs can be populated at runtime
OPPs can be populated statically, via DT, or added at run time with
dev_pm_opp_add().

While this driver handles the first case correctly, it would fail to populate
OPPs added at runtime. Because call to of_init_opp_table() would fail as there
are no OPPs in DT and probe will return early.

To fix this, remove error checking and call dev_pm_opp_init_cpufreq_table()
unconditionally.

Update bindings as well.

Suggested-by: Stephen Boyd <sboyd@codeaurora.org>
Tested-by: Stephen Boyd <sboyd@codeaurora.org>
Signed-off-by: Viresh Kumar <viresh.kumar@linaro.org>
Acked-by: Santosh Shilimkar <santosh.shilimkar@ti.com>
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
2014-07-16 15:12:52 +02:00
Quentin Armitage 2fa1adc070 cpufreq: kirkwood: Reinstate cpufreq driver for ARCH_KIRKWOOD
Commit ff1f0018cf ("drivers: Enable
building of Kirkwood drivers for mach-mvebu") added Kirkwood into
mach-mvebu, adding MACH_KIRKWOOD to ARCH_KIRKWOOD in the KConfig files.

The change for ARM_KIRKWOOD_CPUFREQ replaced ARCH_KIRKWOOD with
MACH_KIRKWOOD, whereas all the other changes were ARCH_KIRKWOOD ||
MACH_KIRKWOOD.

As a consequence of this change, the cpufreq driver is no longer enabled
for ARCH_KIRKWOOD. This patch reinstates ARM_KIRKWOOD_CPUFREQ for
ARCH_KIRKWOOD.

Signed-off-by: Quentin Armitage <quentin@armitage.org.uk>
Acked-by: Andrew Lunn <andrew@lunn.ch>
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
2014-07-16 15:12:03 +02:00
Nicolas Del Piano 7e02168711 cpufreq: imx6q: Select PM_OPP
PM_OPP is a library used by several of the existing cpufreq drivers.
ARM IMX6Q cpufreq driver uses this library for its functionality.
Thus, it should be selected in Kconfig.

Reported-by: Ezequiel Garcia <ezequiel@vanguardiasur.com.ar>
Signed-off-by: Nicolas Del Piano <ndel314@gmail.com>
Acked-by: Viresh Kumar <viresh.kumar@linaro.org>
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
2014-07-16 14:45:37 +02:00
Linus Walleij 97d496bf1a cpufreq: sa1110: set memory type for h3600
The Compaq iPAQ h3600 also has the K4S281632b-1H memory type.
Verified by prying apart a broken board.

Signed-off-by: Linus Walleij <linus.walleij@linaro.org>
Acked-by: Viresh Kumar <viresh.kumar@linaro.org>
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
2014-07-16 14:30:17 +02:00
Prabhakar Lad 5a90af67c2 cpufreq: Makefile: fix compilation for davinci platform
Since commtit 8a7b1227e3 (cpufreq: davinci: move cpufreq driver to
drivers/cpufreq) this added dependancy only for CONFIG_ARCH_DAVINCI_DA850
where as davinci_cpufreq_init() call is used by all davinci platform.

This patch fixes following build error:

arch/arm/mach-davinci/built-in.o: In function `davinci_init_late':
:(.init.text+0x928): undefined reference to `davinci_cpufreq_init'
make: *** [vmlinux] Error 1

Fixes: 8a7b1227e3 (cpufreq: davinci: move cpufreq driver to drivers/cpufreq)
Signed-off-by: Lad, Prabhakar <prabhakar.csengg@gmail.com>
Acked-by: Viresh Kumar <viresh.kumar@linaro.org>
Cc: 3.10+ <stable@vger.kernel.org> # 3.10+
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
2014-07-09 02:54:15 +02:00
Vincent Minet 179e847167 intel_pstate: Set CPU number before accessing MSRs
Ensure that cpu->cpu is set before writing MSR_IA32_PERF_CTL during CPU
initialization. Otherwise only cpu0 has its P-state set and all other
cores are left with their values unchanged.

In most cases, this is not too serious because the P-states will be set
correctly when the timer function is run.  But when the default governor
is set to performance, the per-CPU current_pstate stays the same forever
and no attempts are made to write the MSRs again.

Signed-off-by: Vincent Minet <vincent@vincent-minet.net>
Cc: All applicable <stable@vger.kernel.org>
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
2014-07-07 01:24:24 +02:00
Dirk Brandewie dd5fbf70f9 intel_pstate: don't touch turbo bit if turbo disabled or unavailable.
If turbo is disabled in the BIOS bit 38 should be set in
MSR_IA32_MISC_ENABLE register per section 14.3.2.1 of the SDM Vol 3
document 325384-050US Feb 2014.  If this bit is set do *not* attempt
to disable trubo via the MSR_IA32_PERF_CTL register.  On some systems
trying to disable turbo via MSR_IA32_PERF_CTL will cause subsequent
writes to MSR_IA32_PERF_CTL not take affect, in fact reading
MSR_IA32_PERF_CTL will not show the IDA/Turbo DISENGAGE bit(32) as
set. A write of bit 32 to zero returns to normal operation.

Also deal with the case where the processor does not support
turbo and the BIOS does not report the fact in MSR_IA32_MISC_ENABLE
but does report the max and turbo P states as the same value.

Link: https://bugzilla.kernel.org/show_bug.cgi?id=64251
Cc: 3.13+ <stable@vger.kernel.org>  # 3.13+
Signed-off-by: Dirk Brandewie <dirk.j.brandewie@intel.com>
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
2014-07-07 01:22:19 +02:00
Dirk Brandewie c16ed06024 intel_pstate: Fix setting VID
Commit 21855ff5 (intel_pstate: Set turbo VID for BayTrail) introduced
setting the turbo VID which is required to prevent a machine check on
some Baytrail SKUs under heavy graphics based workloads.  The
docmumentation update that brought the requirement to light also
changed the bit mask used for enumerating P state and VID values from
0x7f to 0x3f.

This change returns the mask value to 0x7f.

Tested with the Intel NUC DN2820FYK,
BIOS version FYBYT10H.86A.0034.2014.0513.1413 with v3.16-rc1 and
v3.14.8 kernel versions.

Fixes: 21855ff5 (intel_pstate: Set turbo VID for BayTrail)
Link: https://bugzilla.kernel.org/show_bug.cgi?id=77951
Reported-and-tested-by: Rune Reterson <rune@megahurts.dk>
Reported-and-tested-by: Eric Eickmeyer <erich@ericheickmeyer.com>
Cc: 3.13+ <stable@vger.kernel.org>  # 3.13+
Signed-off-by: Dirk Brandewie <dirk.j.brandewie@intel.com>
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
2014-07-07 01:22:19 +02:00
Aaron Plattner fefa8ff810 cpufreq: unlock when failing cpufreq_update_policy()
Commit bd0fa9bb45 introduced a failure path to cpufreq_update_policy() if
cpufreq_driver->get(cpu) returns NULL.  However, it jumps to the 'no_policy'
label, which exits without unlocking any of the locks the function acquired
earlier.  This causes later calls into cpufreq to hang.

Fix this by creating a new 'unlock' label and jumping to that instead.

Fixes: bd0fa9bb45 ("cpufreq: Return error if ->get() failed in cpufreq_update_policy()")
Link: https://devtalk.nvidia.com/default/topic/751903/kernel-3-15-and-nv-drivers-337-340-failed-to-initialize-the-nvidia-kernel-module-gtx-550-ti-/
Signed-off-by: Aaron Plattner <aplattner@nvidia.com>
Cc: 3.15+ <stable@vger.kernel.org> # 3.15+
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
2014-06-18 21:52:20 +02:00
Doug Smythies 51d211e9c3 intel_pstate: Correct rounding in busy calculation
There was a mistake in the actual rounding portion this previous patch:
f0fe3cd7e1 (intel_pstate: Correct rounding in busy calculation) such that
the rounding was asymetric and incorrect.

Severity: Not very serious, but can increase target pstate by one extra value.
For real world work flows the issue should self correct (but I have no proof).
It is the equivalent of different PID gains for positive and negative numbers.

Examples:
 -3.000000 used to round to -4, rounds to -3 with this patch.
 -3.503906 used to round to -5, rounds to -4 with this patch.

Fixes: f0fe3cd7e1 (intel_pstate: Correct rounding in busy calculation)
Signed-off-by: Doug Smythies <dsmythies@telus.net>
Cc: 3.14+ <stable@vger.kernel.org> # 3.14+
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
2014-06-17 22:57:40 +02:00
Arnd Bergmann 217886d3f3 cpufreq: cpufreq-cpu0: fix CPU_THERMAL dependency
5fbfbcd3e8 ("cpufreq: cpufreq-cpu0: remove dependency on THERMAL and
REGULATOR") was a little too quick in completely removing the dependency
on the THERMAL driver.

The problem is that while there are inline wrappers to turn the thermal
API calls into empty functions, those do not help if the cpu-thermal
driver is a loadable module and cpufreq-cpu0 is builtin.

Since CONFIG_CPU_THERMAL is a bool option that decides whether the cpu
code is built into the thermal module or not, we have to use a dependency
on the thermal driver itself. However, if CPU_THERMAL is disabled, we
don't need the dependency, hence the strange '!CPU_THERMAL || THERMAL'
construct.

Fixes: 5fbfbcd3e8 ("cpufreq: cpufreq-cpu0: remove dependency on THERMAL and REGULATOR")
Signed-off-by: Arnd Bergmann <arnd@arndb.de>
Tested-by: Viresh Kumar <viresh.kumar@linaro.org>
Acked-by: Viresh Kumar <viresh.kumar@linaro.org>
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
2014-06-16 22:33:38 +02:00
Rafael J. Wysocki 589e18a973 Merge branch 'pm-cpufreq'
* pm-cpufreq:
  cpufreq: cpufreq-cpu0: remove dependency on THERMAL and REGULATOR
  cpufreq: tegra: update comment for clarity
  cpufreq: intel_pstate: Remove duplicate CPU ID check
  cpufreq: Mark CPU0 driver with CPUFREQ_NEED_INITIAL_FREQ_CHECK flag
  cpufreq: governor: remove copy_prev_load from 'struct cpu_dbs_common_info'
  cpufreq: governor: Be friendly towards latency-sensitive bursty workloads
  cpufreq: ppc-corenet-cpu-freq: do_div use quotient
  Revert "cpufreq: Enable big.LITTLE cpufreq driver on arm64"
  cpufreq: Tegra: implement intermediate frequency callbacks
  cpufreq: add support for intermediate (stable) frequencies
2014-06-12 13:43:02 +02:00
Viresh Kumar 5fbfbcd3e8 cpufreq: cpufreq-cpu0: remove dependency on THERMAL and REGULATOR
cpufreq-cpu0 uses thermal framework to register a cooling device, but doesn't
depend on it as there are dummy calls provided by thermal layer when
CONFIG_THERMAL=n. And when these calls fail, the driver is still usable.

Similar explanation is valid for regulators as well. We do have dummy calls
available for regulator APIs and the driver can work even when those calls
fail.

So, we don't really need to mention thermal and regulators as a dependency for
cpufreq-cpu0 in Kconfig as platforms without support for thermal/regulator can
also use this driver. Remove this dependency.

Signed-off-by: Viresh Kumar <viresh.kumar@linaro.org>
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
2014-06-10 22:52:35 +02:00
Viresh Kumar 40cc549013 cpufreq: tegra: update comment for clarity
Tegra's driver got updated a bit (00917dd cpufreq: Tegra: implement intermediate
frequency callbacks) and implements new 'intermediate freq' infrastructure of
core. Above commit updated comments about when to call
clk_prepare_enable(pll_x_clk) and Doug wasn't satisfied with those comments and
said this:

> The "Though when target-freq is intermediate freq, we don't need to
> take this reference." makes me think that this function is actually
> called when target-freq is intermediate freq.  I don't think it is,
> right?

For better clarity just make that comment more explicit about when we call
tegra_target_intermediate().

Reviewed-by: Stephen Warren <swarren@nvidia.com>
Reported-and-reviewed-by: Doug Anderson <dianders@chromium.org>
Signed-off-by: Viresh Kumar <viresh.kumar@linaro.org>
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
2014-06-10 22:50:50 +02:00
Stratos Karafotis 830bcac4e4 cpufreq: intel_pstate: Remove duplicate CPU ID check
We check the CPU ID during driver init. There is no need
to do it again per logical CPU initialization.

So, remove the duplicate check.

Signed-off-by: Stratos Karafotis <stratosk@semaphore.gr>
Acked-by: Viresh Kumar <viresh.kumar@linaro.org>
Acked-by: Dirk Brandewie <dirk.j.brandewie@intel.com>
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
2014-06-10 22:49:41 +02:00
Viresh Kumar 93575b7578 cpufreq: Mark CPU0 driver with CPUFREQ_NEED_INITIAL_FREQ_CHECK flag
Sometimes boot loaders set CPU frequency to a value outside of frequency table
present with cpufreq core. In such cases CPU might be unstable if it has to run
on that frequency for long duration of time and so its better to set it to a
frequency which is specified in frequency table.

Sachin recently found this problem with cpufreq-cpu0 driver when he was testing
it for Exynos.

Set this flag for cpufreq-cpu0 driver.

Reported-and-tested-by: Sachin Kamat <sachin.kamat@linaro.org>
Signed-off-by: Viresh Kumar <viresh.kumar@linaro.org>
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
2014-06-09 22:55:48 +02:00
Viresh Kumar c8ae481b9a cpufreq: governor: remove copy_prev_load from 'struct cpu_dbs_common_info'
'copy_prev_load' was recently added by commit: 18b46ab (cpufreq: governor: Be
friendly towards latency-sensitive bursty workloads).

It actually is a bit redundant as we also have 'prev_load' which can store any
integer value and can be used instead of 'copy_prev_load' by setting it zero.

True load can also turn out to be zero during long idle intervals (and hence the
actual value of 'prev_load' and the overloaded value can clash). However this is
not a problem because, if the true load was really zero in the previous
interval, it makes sense to evaluate the load afresh for the current interval
rather than copying the previous load.

So, drop 'copy_prev_load' and use 'prev_load' instead.

Update comments as well to make it more clear.

There is another change here which was probably missed by Srivatsa during the
last version of updates he made. The unlikely in the 'if' statement was covering
only half of the condition and the whole line should actually come under it.

Also checkpatch is made more silent as it was reporting this (--strict option):

CHECK: Alignment should match open parenthesis
+		if (unlikely(wall_time > (2 * sampling_rate) &&
+						j_cdbs->prev_load)) {

Signed-off-by: Viresh Kumar <viresh.kumar@linaro.org>
Reviewed-by: Srivatsa S. Bhat <srivatsa.bhat@linux.vnet.ibm.com>
Acked-by: Pavel Machek <pavel@ucw.cz>
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
2014-06-09 12:58:21 +02:00
Srivatsa S. Bhat 18b46abd00 cpufreq: governor: Be friendly towards latency-sensitive bursty workloads
Cpufreq governors like the ondemand governor calculate the load on the CPU
periodically by employing deferrable timers. A deferrable timer won't fire
if the CPU is completely idle (and there are no other timers to be run), in
order to avoid unnecessary wakeups and thus save CPU power.

However, the load calculation logic is agnostic to all this, and this can
lead to the problem described below.

Time (ms)               CPU 1

100                Task-A running

110                Governor's timer fires, finds load as 100% in the last
                   10ms interval and increases the CPU frequency.

110.5              Task-A running

120		   Governor's timer fires, finds load as 100% in the last
		   10ms interval and increases the CPU frequency.

125		   Task-A went to sleep. With nothing else to do, CPU 1
		   went completely idle.

200		   Task-A woke up and started running again.

200.5		   Governor's deferred timer (which was originally programmed
		   to fire at time 130) fires now. It calculates load for the
		   time period 120 to 200.5, and finds the load is almost zero.
		   Hence it decreases the CPU frequency to the minimum.

210		   Governor's timer fires, finds load as 100% in the last
		   10ms interval and increases the CPU frequency.

So, after the workload woke up and started running, the frequency was suddenly
dropped to absolute minimum, and after that, there was an unnecessary delay of
10ms (sampling period) to increase the CPU frequency back to a reasonable value.
And this pattern repeats for every wake-up-from-cpu-idle for that workload.
This can be quite undesirable for latency- or response-time sensitive bursty
workloads. So we need to fix the governor's logic to detect such wake-up-from-
cpu-idle scenarios and start the workload at a reasonably high CPU frequency.

One extreme solution would be to fake a load of 100% in such scenarios. But
that might lead to undesirable side-effects such as frequency spikes (which
might also need voltage changes) especially if the previous frequency happened
to be very low.

We just want to avoid the stupidity of dropping down the frequency to a minimum
and then enduring a needless (and long) delay before ramping it up back again.
So, let us simply carry forward the previous load - that is, let us just pretend
that the 'load' for the current time-window is the same as the load for the
previous window. That way, the frequency and voltage will continue to be set
to whatever values they were set at previously. This means that bursty workloads
will get a chance to influence the CPU frequency at which they wake up from
cpu-idle, based on their past execution history. Thus, they might be able to
avoid suffering from slow wakeups and long response-times.

However, we should take care not to over-do this. For example, such a "copy
previous load" logic will benefit cases like this: (where # represents busy
and . represents idle)

##########.........#########.........###########...........##########........

but it will be detrimental in cases like the one shown below, because it will
retain the high frequency (copied from the previous interval) even in a mostly
idle system:

##########.........#.................#.....................#...............

(i.e., the workload finished and the remaining tasks are such that their busy
periods are smaller than the sampling interval, which causes the timer to
always get deferred. So, this will make the copy-previous-load logic copy
the initial high load to subsequent idle periods over and over again, thus
keeping the frequency high unnecessarily).

So, we modify this copy-previous-load logic such that it is used only once
upon every wakeup-from-idle. Thus if we have 2 consecutive idle periods, the
previous load won't get blindly copied over; cpufreq will freshly evaluate the
load in the second idle interval, thus ensuring that the system comes back to
its normal state.

[ The right way to solve this whole problem is to teach the CPU frequency
governors to also track load on a per-task basis, not just a per-CPU basis,
and then use both the data sources intelligently to set the appropriate
frequency on the CPUs. But that involves redesigning the cpufreq subsystem,
so this patch should make the situation bearable until then. ]

Experimental results:
+-------------------+

I ran a modified version of ebizzy (called 'sleeping-ebizzy') that sleeps in
between its execution such that its total utilization can be a user-defined
value, say 10% or 20% (higher the utilization specified, lesser the amount of
sleeps injected). This ebizzy was run with a single-thread, tied to CPU 8.

Behavior observed with tracing (sample taken from 40% utilization runs):
------------------------------------------------------------------------

Without patch:
~~~~~~~~~~~~~~
kworker/8:2-12137  416.335742: cpu_frequency: state=2061000 cpu_id=8
kworker/8:2-12137  416.335744: sched_switch: prev_comm=kworker/8:2 ==> next_comm=ebizzy
      <...>-40753  416.345741: sched_switch: prev_comm=ebizzy ==> next_comm=kworker/8:2
kworker/8:2-12137  416.345744: cpu_frequency: state=4123000 cpu_id=8
kworker/8:2-12137  416.345746: sched_switch: prev_comm=kworker/8:2 ==> next_comm=ebizzy
      <...>-40753  416.355738: sched_switch: prev_comm=ebizzy ==> next_comm=kworker/8:2
<snip>  ---------------------------------------------------------------------  <snip>
      <...>-40753  416.402202: sched_switch: prev_comm=ebizzy ==> next_comm=swapper/8
     <idle>-0      416.502130: sched_switch: prev_comm=swapper/8 ==> next_comm=ebizzy
      <...>-40753  416.505738: sched_switch: prev_comm=ebizzy ==> next_comm=kworker/8:2
kworker/8:2-12137  416.505739: cpu_frequency: state=2061000 cpu_id=8
kworker/8:2-12137  416.505741: sched_switch: prev_comm=kworker/8:2 ==> next_comm=ebizzy
      <...>-40753  416.515739: sched_switch: prev_comm=ebizzy ==> next_comm=kworker/8:2
kworker/8:2-12137  416.515742: cpu_frequency: state=4123000 cpu_id=8
kworker/8:2-12137  416.515744: sched_switch: prev_comm=kworker/8:2 ==> next_comm=ebizzy

Observation: Ebizzy went idle at 416.402202, and started running again at
416.502130. But cpufreq noticed the long idle period, and dropped the frequency
at 416.505739, only to increase it back again at 416.515742, realizing that the
workload is in-fact CPU bound. Thus ebizzy needlessly ran at the lowest frequency
for almost 13 milliseconds (almost 1 full sample period), and this pattern
repeats on every sleep-wakeup. This could hurt latency-sensitive workloads quite
a lot.

With patch:
~~~~~~~~~~~

kworker/8:2-29802  464.832535: cpu_frequency: state=2061000 cpu_id=8
<snip>  ---------------------------------------------------------------------  <snip>
kworker/8:2-29802  464.962538: sched_switch: prev_comm=kworker/8:2 ==> next_comm=ebizzy
      <...>-40738  464.972533: sched_switch: prev_comm=ebizzy ==> next_comm=kworker/8:2
kworker/8:2-29802  464.972536: cpu_frequency: state=4123000 cpu_id=8
kworker/8:2-29802  464.972538: sched_switch: prev_comm=kworker/8:2 ==> next_comm=ebizzy
      <...>-40738  464.982531: sched_switch: prev_comm=ebizzy ==> next_comm=kworker/8:2
<snip>  ---------------------------------------------------------------------  <snip>
kworker/8:2-29802  465.022533: sched_switch: prev_comm=kworker/8:2 ==> next_comm=ebizzy
      <...>-40738  465.032531: sched_switch: prev_comm=ebizzy ==> next_comm=kworker/8:2
kworker/8:2-29802  465.032532: sched_switch: prev_comm=kworker/8:2 ==> next_comm=ebizzy
      <...>-40738  465.035797: sched_switch: prev_comm=ebizzy ==> next_comm=swapper/8
     <idle>-0      465.240178: sched_switch: prev_comm=swapper/8 ==> next_comm=ebizzy
      <...>-40738  465.242533: sched_switch: prev_comm=ebizzy ==> next_comm=kworker/8:2
kworker/8:2-29802  465.242535: sched_switch: prev_comm=kworker/8:2 ==> next_comm=ebizzy
      <...>-40738  465.252531: sched_switch: prev_comm=ebizzy ==> next_comm=kworker/8:2

Observation: Ebizzy went idle at 465.035797, and started running again at
465.240178. Since ebizzy was the only real workload running on this CPU,
cpufreq retained the frequency at 4.1Ghz throughout the run of ebizzy, no
matter how many times ebizzy slept and woke-up in-between. Thus, ebizzy
got the 10ms worth of 4.1 Ghz benefit during every sleep-wakeup (as compared
to the run without the patch) and this boost gave a modest improvement in total
throughput, as shown below.

Sleeping-ebizzy records-per-second:
-----------------------------------

Utilization  Without patch  With patch  Difference (Absolute and % values)
    10%         274767        277046        +  2279 (+0.829%)
    20%         543429        553484        + 10055 (+1.850%)
    40%        1090744       1107959        + 17215 (+1.578%)
    60%        1634908       1662018        + 27110 (+1.658%)

A rudimentary and somewhat approximately latency-sensitive workload such as
sleeping-ebizzy itself showed a consistent, noticeable performance improvement
with this patch. Hence, workloads that are truly latency-sensitive will benefit
quite a bit from this change. Moreover, this is an overall win-win since this
patch does not hurt power-savings at all (because, this patch does not reduce
the idle time or idle residency; and the high frequency of the CPU when it goes
to cpu-idle does not affect/hurt the power-savings of deep idle states).

Signed-off-by: Srivatsa S. Bhat <srivatsa.bhat@linux.vnet.ibm.com>
Reviewed-by: Gautham R. Shenoy <ego@linux.vnet.ibm.com>
Acked-by: Viresh Kumar <viresh.kumar@linaro.org>
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
2014-06-07 22:53:51 +02:00
Ed Swarthout 906fe03314 cpufreq: ppc-corenet-cpu-freq: do_div use quotient
Commit 6712d29319 (cpufreq: ppc-corenet-cpufreq: Fix __udivdi3 modpost
error) used the remainder from do_div instead of the quotient.  Fix that
and add one to ensure minimum is met.

Fixes: 6712d29319 (cpufreq: ppc-corenet-cpufreq: Fix __udivdi3 modpost error)
Signed-off-by: Ed Swarthout <Ed.Swarthout@freescale.com>
Cc: 3.15+ <stable@vger.kernel.org> # 3.15+
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
2014-06-06 22:50:43 +02:00
Rafael J. Wysocki 57aa5ea0ee Revert "cpufreq: Enable big.LITTLE cpufreq driver on arm64"
This reverts commit 4920ab8497 (cpufreq: Enable big.LITTLE cpufreq
driver on arm64) that breaks build on arm64.

Fixes: 4920ab8497 (cpufreq: Enable big.LITTLE cpufreq driver on arm64)
Reported-by: Catalin Marinas <catalin.marinas@arm.com>
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
2014-06-06 22:50:18 +02:00
Viresh Kumar 00917ddc7c cpufreq: Tegra: implement intermediate frequency callbacks
Tegra has been switching to intermediate frequency (pll_p_clk) forever.
CPUFreq core has better support for handling notifications for these
frequencies and so we can adapt Tegra's driver to it.

Also do a WARN() if clk_set_parent() fails while moving back to pll_x
as we should have atleast restored to earlier frequency on error.

Tested-by: Stephen Warren <swarren@nvidia.com>
Signed-off-by: Viresh Kumar <viresh.kumar@linaro.org>
Reviewed-by: Doug Anderson <dianders@chromium.org>
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
2014-06-05 23:34:07 +02:00
Viresh Kumar 1c03a2d04d cpufreq: add support for intermediate (stable) frequencies
Douglas Anderson, recently pointed out an interesting problem due to which
udelay() was expiring earlier than it should.

While transitioning between frequencies few platforms may temporarily switch to
a stable frequency, waiting for the main PLL to stabilize.

For example: When we transition between very low frequencies on exynos, like
between 200MHz and 300MHz, we may temporarily switch to a PLL running at 800MHz.
No CPUFREQ notification is sent for that. That means there's a period of time
when we're running at 800MHz but loops_per_jiffy is calibrated at between 200MHz
and 300MHz. And so udelay behaves badly.

To get this fixed in a generic way, introduce another set of callbacks
get_intermediate() and target_intermediate(), only for drivers with
target_index() and CPUFREQ_ASYNC_NOTIFICATION unset.

get_intermediate() should return a stable intermediate frequency platform wants
to switch to, and target_intermediate() should set CPU to that frequency,
before jumping to the frequency corresponding to 'index'. Core will take care of
sending notifications and driver doesn't have to handle them in
target_intermediate() or target_index().

NOTE: ->target_index() should restore to policy->restore_freq in case of
failures as core would send notifications for that.

Tested-by: Stephen Warren <swarren@nvidia.com>
Signed-off-by: Viresh Kumar <viresh.kumar@linaro.org>
Reviewed-by: Doug Anderson <dianders@chromium.org>
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
2014-06-05 23:32:29 +02:00
Linus Torvalds 4dc4226f99 ACPI and power management updates for 3.16-rc1
- ACPICA update to upstream version 20140424.  That includes a
    number of fixes and improvements related to things like GPE
    handling, table loading, headers, memory mapping and unmapping,
    DSDT/SSDT overriding, and the Unload() operator.  The acpidump
    utility from upstream ACPICA is included too.  From Bob Moore,
    Lv Zheng, David Box, David Binderman, and Colin Ian King.
 
  - Fixes and cleanups related to ACPI video and backlight interfaces
    from Hans de Goede.  That includes blacklist entries for some new
    machines and using native backlight by default.
 
  - ACPI device enumeration changes to create platform devices
    rather than PNP devices for ACPI device objects with _HID by
    default.  PNP devices will still be created for the ACPI device
    object with device IDs corresponding to real PNP devices, so
    that change should not break things left and right, and we're
    expecting to see more and more ACPI-enumerated platform devices
    in the future.  From Zhang Rui and Rafael J Wysocki.
 
  - Updates for the ACPI LPSS (Low-Power Subsystem) driver allowing
    it to handle system suspend/resume on Asus T100 correctly.
    From Heikki Krogerus and Rafael J Wysocki.
 
  - PM core update introducing a mechanism to allow runtime-suspended
    devices to stay suspended over system suspend/resume transitions
    if certain additional conditions related to coordination within
    device hierarchy are met.  Related PM documentation update and
    ACPI PM domain support for the new feature.  From Rafael J Wysocki.
 
  - Fixes and improvements related to the "freeze" sleep state. They
    affect several places including cpuidle, PM core, ACPI core, and
    the ACPI battery driver.  From Rafael J Wysocki and Zhang Rui.
 
  - Miscellaneous fixes and updates of the ACPI core from Aaron Lu,
    Bjørn Mork, Hanjun Guo, Lan Tianyu, and Rafael J Wysocki.
 
  - Fixes and cleanups for the ACPI processor and ACPI PAD (Processor
    Aggregator Device) drivers from Baoquan He, Manuel Schölling,
    Tony Camuso, and Toshi Kani.
 
  - System suspend/resume optimization in the ACPI battery driver from
    Lan Tianyu.
 
  - OPP (Operating Performance Points) subsystem updates from
    Chander Kashyap, Mark Brown, and Nishanth Menon.
 
  - cpufreq core fixes, updates and cleanups from Srivatsa S Bhat,
    Stratos Karafotis, and Viresh Kumar.
 
  - Updates, fixes and cleanups for the Tegra, powernow-k8, imx6q,
    s5pv210, nforce2, and powernv cpufreq drivers from Brian Norris,
    Jingoo Han, Paul Bolle, Philipp Zabel, Stratos Karafotis, and
    Viresh Kumar.
 
  - intel_pstate driver fixes and cleanups from Dirk Brandewie,
    Doug Smythies, and Stratos Karafotis.
 
  - Enabling the big.LITTLE cpufreq driver on arm64 from Mark Brown.
 
  - Fix for the cpuidle menu governor from Chander Kashyap.
 
  - New ARM clps711x cpuidle driver from Alexander Shiyan.
 
  - Hibernate core fixes and cleanups from Chen Gang, Dan Carpenter,
    Fabian Frederick, Pali Rohár, and Sebastian Capella.
 
  - Intel RAPL (Running Average Power Limit) driver updates from
    Jacob Pan.
 
  - PNP subsystem updates from Bjorn Helgaas and Fabian Frederick.
 
  - devfreq core updates from Chanwoo Choi and Paul Bolle.
 
  - devfreq updates for exynos4 and exynos5 from Chanwoo Choi and
    Bartlomiej Zolnierkiewicz.
 
  - turbostat tool fix from Jean Delvare.
 
  - cpupower tool updates from Prarit Bhargava, Ramkumar Ramachandra
    and Thomas Renninger.
 
  - New ACPI ec_access.c tool for poking at the EC in a safe way
    from Thomas Renninger.
 
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Merge tag 'pm+acpi-3.16-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/rafael/linux-pm into next

Pull ACPI and power management updates from Rafael Wysocki:
 "ACPICA is the leader this time (63 commits), followed by cpufreq (28
  commits), devfreq (15 commits), system suspend/hibernation (12
  commits), ACPI video and ACPI device enumeration (10 commits each).

  We have no major new features this time, but there are a few
  significant changes of how things work.  The most visible one will
  probably be that we are now going to create platform devices rather
  than PNP devices by default for ACPI device objects with _HID.  That
  was long overdue and will be really necessary to be able to use the
  same drivers for the same hardware blocks on ACPI and DT-based systems
  going forward.  We're not expecting fallout from this one (as usual),
  but it's something to watch nevertheless.

  The second change having a chance to be visible is that ACPI video
  will now default to using native backlight rather than the ACPI
  backlight interface which should generally help systems with broken
  Win8 BIOSes.  We're hoping that all problems with the native backlight
  handling that we had previously have been addressed and we are in a
  good enough shape to flip the default, but this change should be easy
  enough to revert if need be.

  In addition to that, the system suspend core has a new mechanism to
  allow runtime-suspended devices to stay suspended throughout system
  suspend/resume transitions if some extra conditions are met
  (generally, they are related to coordination within device hierarchy).
  However, enabling this feature requires cooperation from the bus type
  layer and for now it has only been implemented for the ACPI PM domain
  (used by ACPI-enumerated platform devices mostly today).

  Also, the acpidump utility that was previously shipped as a separate
  tool will now be provided by the upstream ACPICA along with the rest
  of ACPICA code, which will allow it to be more up to date and better
  supported, and we have one new cpuidle driver (ARM clps711x).

  The rest is improvements related to certain specific use cases,
  cleanups and fixes all over the place.

  Specifics:

   - ACPICA update to upstream version 20140424.  That includes a number
     of fixes and improvements related to things like GPE handling,
     table loading, headers, memory mapping and unmapping, DSDT/SSDT
     overriding, and the Unload() operator.  The acpidump utility from
     upstream ACPICA is included too.  From Bob Moore, Lv Zheng, David
     Box, David Binderman, and Colin Ian King.

   - Fixes and cleanups related to ACPI video and backlight interfaces
     from Hans de Goede.  That includes blacklist entries for some new
     machines and using native backlight by default.

   - ACPI device enumeration changes to create platform devices rather
     than PNP devices for ACPI device objects with _HID by default.  PNP
     devices will still be created for the ACPI device object with
     device IDs corresponding to real PNP devices, so that change should
     not break things left and right, and we're expecting to see more
     and more ACPI-enumerated platform devices in the future.  From
     Zhang Rui and Rafael J Wysocki.

   - Updates for the ACPI LPSS (Low-Power Subsystem) driver allowing it
     to handle system suspend/resume on Asus T100 correctly.  From
     Heikki Krogerus and Rafael J Wysocki.

   - PM core update introducing a mechanism to allow runtime-suspended
     devices to stay suspended over system suspend/resume transitions if
     certain additional conditions related to coordination within device
     hierarchy are met.  Related PM documentation update and ACPI PM
     domain support for the new feature.  From Rafael J Wysocki.

   - Fixes and improvements related to the "freeze" sleep state.  They
     affect several places including cpuidle, PM core, ACPI core, and
     the ACPI battery driver.  From Rafael J Wysocki and Zhang Rui.

   - Miscellaneous fixes and updates of the ACPI core from Aaron Lu,
     Bjørn Mork, Hanjun Guo, Lan Tianyu, and Rafael J Wysocki.

   - Fixes and cleanups for the ACPI processor and ACPI PAD (Processor
     Aggregator Device) drivers from Baoquan He, Manuel Schölling, Tony
     Camuso, and Toshi Kani.

   - System suspend/resume optimization in the ACPI battery driver from
     Lan Tianyu.

   - OPP (Operating Performance Points) subsystem updates from Chander
     Kashyap, Mark Brown, and Nishanth Menon.

   - cpufreq core fixes, updates and cleanups from Srivatsa S Bhat,
     Stratos Karafotis, and Viresh Kumar.

   - Updates, fixes and cleanups for the Tegra, powernow-k8, imx6q,
     s5pv210, nforce2, and powernv cpufreq drivers from Brian Norris,
     Jingoo Han, Paul Bolle, Philipp Zabel, Stratos Karafotis, and
     Viresh Kumar.

   - intel_pstate driver fixes and cleanups from Dirk Brandewie, Doug
     Smythies, and Stratos Karafotis.

   - Enabling the big.LITTLE cpufreq driver on arm64 from Mark Brown.

   - Fix for the cpuidle menu governor from Chander Kashyap.

   - New ARM clps711x cpuidle driver from Alexander Shiyan.

   - Hibernate core fixes and cleanups from Chen Gang, Dan Carpenter,
     Fabian Frederick, Pali Rohár, and Sebastian Capella.

   - Intel RAPL (Running Average Power Limit) driver updates from Jacob
     Pan.

   - PNP subsystem updates from Bjorn Helgaas and Fabian Frederick.

   - devfreq core updates from Chanwoo Choi and Paul Bolle.

   - devfreq updates for exynos4 and exynos5 from Chanwoo Choi and
     Bartlomiej Zolnierkiewicz.

   - turbostat tool fix from Jean Delvare.

   - cpupower tool updates from Prarit Bhargava, Ramkumar Ramachandra
     and Thomas Renninger.

   - New ACPI ec_access.c tool for poking at the EC in a safe way from
     Thomas Renninger"

* tag 'pm+acpi-3.16-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/rafael/linux-pm: (187 commits)
  ACPICA: Namespace: Remove _PRP method support.
  intel_pstate: Improve initial busy calculation
  intel_pstate: add sample time scaling
  intel_pstate: Correct rounding in busy calculation
  intel_pstate: Remove C0 tracking
  PM / hibernate: fixed typo in comment
  ACPI: Fix x86 regression related to early mapping size limitation
  ACPICA: Tables: Add mechanism to control early table checksum verification.
  ACPI / scan: use platform bus type by default for _HID enumeration
  ACPI / scan: always register ACPI LPSS scan handler
  ACPI / scan: always register memory hotplug scan handler
  ACPI / scan: always register container scan handler
  ACPI / scan: Change the meaning of missing .attach() in scan handlers
  ACPI / scan: introduce platform_id device PNP type flag
  ACPI / scan: drop unsupported serial IDs from PNP ACPI scan handler ID list
  ACPI / scan: drop IDs that do not comply with the ACPI PNP ID rule
  ACPI / PNP: use device ID list for PNPACPI device enumeration
  ACPI / scan: .match() callback for ACPI scan handlers
  ACPI / battery: wakeup the system only when necessary
  power_supply: allow power supply devices registered w/o wakeup source
  ...
2014-06-04 08:57:16 -07:00