cpufreq_init_policy() can fail, and we don't do anything except a call
to ->exit() on that. The policy should be freed if this happens.

Do it properly.
Reported-and-tested-by: N"Jon Medhurst (Tixy)" <tixy@linaro.org>
Signed-off-by: NViresh Kumar <viresh.kumar@linaro.org>
Signed-off-by: NRafael J. Wysocki <rafael.j.wysocki@intel.com>

These labels are are named in two ways normally:
 - Based on what caused to jump to such labels
 - Based on what we do under such labels

We follow the first naming convention today and that leads to multiple
labels for doing the same work. Fix it by switching to the second way of
naming them.
Signed-off-by: NViresh Kumar <viresh.kumar@linaro.org>
Signed-off-by: NRafael J. Wysocki <rafael.j.wysocki@intel.com>

Drivers can store their internal per-policy information in
policy->driver_data, lets use it.

we have benefits after this replacing.
1) memory saving.
2) policy is shared by several cpus, per_cpu seems not correct. using
*driver_data* is more reasonable.
3) fix a memory leak in acpi_cpufreq_cpu_exit. as policy->cpu might
change during cpu hotplug. So sometimes we cant't free *data*, use
*driver_data* to fix it.
4) fix a zero return value of get_cur_freq_on_cpu. Only per_cpu of
policy->cpu is set to *data*, if we try to get cpufreq on other cpus, we
get zero instead of correct values. Use *driver_data* to fix it.
Signed-off-by: NPan Xinhui <xinhuix.pan@intel.com>
Acked-by: NViresh Kumar <viresh.kumar@linaro.org>
Signed-off-by: NRafael J. Wysocki <rafael.j.wysocki@intel.com>

Users of freq table may want to access it for any CPU from
policy->related_cpus mask. One such user is cpu-cooling layer. It gets a
list of 'clip_cpus' (equivalent to policy->related_cpus) during
registration and tries to get freq_table for the first CPU of this mask.

If the CPU, for which it tries to fetch freq_table, is offline,
cpufreq_frequency_get_table() fails. This happens because it relies on
cpufreq_cpu_get_raw() for its functioning which returns policy only for
online CPUs.

The fix is to access the policy data structure for the given CPU
directly (which also returns a valid policy for offline CPUs), but the
policy itself has to be active (meaning that at least one CPU using it
is online) for the frequency table to be returned.

Because we will be using 'cpufreq_cpu_data' now, which is internal to
the cpufreq core, move cpufreq_frequency_get_table() to cpufreq.c.
Reported-and-tested-by: NPi-Cheng Chen <pi-cheng.chen@linaro.org>
Signed-off-by: NViresh Kumar <viresh.kumar@linaro.org>
Signed-off-by: NRafael J. Wysocki <rafael.j.wysocki@intel.com>

When all CPUs of a policy are hot-unplugged, we EXIT the governor but
don't mark policy->governor as NULL. This was done in order to keep last
used governor's information intact in sysfs, while the CPUs are offline.

But we also need to clear policy->governor when restoring the policy.

Because policy->governor still points to the last governor while policy
is restored, following sequence of event happens:
 - cpufreq_init_policy() called while restoring policy
 - find_governor() matches last_governor string for present governors and
   returns last used governor's pointer, say ondemand. policy->governor
   already has the same address, unless the governor was removed in
   between.
 - cpufreq_set_policy() is called with both old/new policies governor set
   as ondemand.
 - Because governors matched, we skip governor initialization and return
   after calling __cpufreq_governor(CPUFREQ_GOV_LIMITS). Because the
   governor wasn't initialized for this policy, it returned -EBUSY.
 - cpufreq_init_policy() exits the policy on this error, but doesn't
   destroy it properly (should be fixed separately).
 - And so we enter a scenario where the policy isn't completely
   initialized but used.

Fix this by setting policy->governor to NULL while restoring the policy.
Reported-and-tested-by: NPi-Cheng Chen <pi-cheng.chen@linaro.org>
Reported-and-tested-by: N"Jon Medhurst (Tixy)" <tixy@linaro.org>
Reported-and-tested-by: NSteven Rostedt <rostedt@goodmis.org>
Fixes: 18bf3a12 (cpufreq: Mark policy->governor = NULL for inactive policies)
Signed-off-by: NViresh Kumar <viresh.kumar@linaro.org>
Signed-off-by: NRafael J. Wysocki <rafael.j.wysocki@intel.com>

Currently, code of Loongson-2/3 is under loongson directory and code of
Loongson-1 is under loongson1 directory. Besides, there are Kconfig
options such as MACH_LOONGSON and MACH_LOONGSON1. This naming style is
very ugly and confusing. Since Loongson-2/3 are both 64-bit general-
purpose CPU while Loongson-1 is 32-bit SoC, we rename both file names
and Kconfig symbols from loongson/loongson1 to loongson64/loongson32.

[ralf@linux-mips.org: Resolve a number of simple conflicts.]
Signed-off-by: NHuacai Chen <chenhc@lemote.com>
Cc: Steven J. Hill <Steven.Hill@imgtec.com>
Cc: linux-mips@linux-mips.org
Cc: Fuxin Zhang <zhangfx@lemote.com>
Cc: Zhangjin Wu <wuzhangjin@gmail.com>
Cc: Kelvin Cheung <keguang.zhang@gmail.com>
Patchwork: https://patchwork.linux-mips.org/patch/9790/Signed-off-by: NRalf Baechle <ralf@linux-mips.org>

Exynos4210 based platforms have switched over to use generic
cpufreq driver for cpufreq functionality. So the Exynos
specific cpufreq support for these platforms can be removed.

Changes by Bartlomiej:
- dropped Exynos5250 support removal for now
- updated exynos-cpufreq.[c,h]

Cc: Javier Martinez Canillas <javier.martinez@collabora.co.uk>
Acked-by: NViresh Kumar <viresh.kumar@linaro.org>
Signed-off-by: NThomas Abraham <thomas.ab@samsung.com>
Signed-off-by: NBartlomiej Zolnierkiewicz <b.zolnierkie@samsung.com>
Signed-off-by: NMichael Turquette <mturquette@baylibre.com>

by adding the missing MODULE_ALIAS(), cpufreq-dt
can be autoloaded by udev/systemd.
Signed-off-by: NFelipe Balbi <balbi@ti.com>
Acked-by: NNishanth Menon <nm@ti.com>
Acked-by: NViresh Kumar <viresh.kumar@linaro.org>
Signed-off-by: NRafael J. Wysocki <rafael.j.wysocki@intel.com>

The kernel may delay interrupts for a long time which can result in timers
being delayed. If this occurs the intel_pstate driver will crash with a
divide by zero error:

divide error: 0000 [#1] SMP
Modules linked in: btrfs zlib_deflate raid6_pq xor msdos ext4 mbcache jbd2 binfmt_misc arc4 md4 nls_utf8 cifs dns_resolver tcp_lp bnep bluetooth rfkill fuse dm_service_time iscsi_tcp libiscsi_tcp libiscsi scsi_transport_iscsi nf_conntrack_netbios_ns nf_conntrack_broadcast nf_conntrack_ftp ip6t_rpfilter ip6t_REJECT ipt_REJECT xt_conntrack ebtable_nat ebtable_broute bridge stp llc ebtable_filter ebtables ip6table_nat nf_conntrack_ipv6 nf_defrag_ipv6 nf_nat_ipv6 ip6table_mangle ip6table_security ip6table_raw ip6table_filter ip6_tables iptable_nat nf_conntrack_ipv4 nf_defrag_ipv4 nf_nat_ipv4 nf_nat nf_conntrack iptable_mangle iptable_security iptable_raw iptable_filter ip_tables intel_powerclamp coretemp vfat fat kvm_intel iTCO_wdt iTCO_vendor_support ipmi_devintf sr_mod kvm crct10dif_pclmul
 crc32_pclmul crc32c_intel ghash_clmulni_intel aesni_intel cdc_ether lrw usbnet cdrom mii gf128mul glue_helper ablk_helper cryptd lpc_ich mfd_core pcspkr sb_edac edac_core ipmi_si ipmi_msghandler ioatdma wmi shpchp acpi_pad nfsd auth_rpcgss nfs_acl lockd uinput dm_multipath sunrpc xfs libcrc32c usb_storage sd_mod crc_t10dif crct10dif_common ixgbe mgag200 syscopyarea sysfillrect sysimgblt mdio drm_kms_helper ttm igb drm ptp pps_core dca i2c_algo_bit megaraid_sas i2c_core dm_mirror dm_region_hash dm_log dm_mod
CPU: 113 PID: 0 Comm: swapper/113 Tainted: G        W   --------------   3.10.0-229.1.2.el7.x86_64 #1
Hardware name: IBM x3950 X6 -[3837AC2]-/00FN827, BIOS -[A8E112BUS-1.00]- 08/27/2014
task: ffff880fe8abe660 ti: ffff880fe8ae4000 task.ti: ffff880fe8ae4000
RIP: 0010:[<ffffffff814a9279>]  [<ffffffff814a9279>] intel_pstate_timer_func+0x179/0x3d0
RSP: 0018:ffff883fff4e3db8  EFLAGS: 00010206
RAX: 0000000027100000 RBX: ffff883fe6965100 RCX: 0000000000000000
RDX: 0000000000000000 RSI: 0000000000000010 RDI: 000000002e53632d
RBP: ffff883fff4e3e20 R08: 000e6f69a5a125c0 R09: ffff883fe84ec001
R10: 0000000000000002 R11: 0000000000000005 R12: 00000000000049f5
R13: 0000000000271000 R14: 00000000000049f5 R15: 0000000000000246
FS:  0000000000000000(0000) GS:ffff883fff4e0000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 00007f7668601000 CR3: 000000000190a000 CR4: 00000000001407e0
DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
DR3: 0000000000000000 DR6: 00000000ffff0ff0 DR7: 0000000000000400
Stack:
 ffff883fff4e3e58 ffffffff81099dc1 0000000000000086 0000000000000071
 ffff883fff4f3680 0000000000000071 fbdc8a965e33afee ffffffff810b69dd
 ffff883fe84ec000 ffff883fe6965108 0000000000000100 ffffffff814a9100
Call Trace:
 <IRQ>

 [<ffffffff81099dc1>] ? run_posix_cpu_timers+0x51/0x840
 [<ffffffff810b69dd>] ? trigger_load_balance+0x5d/0x200
 [<ffffffff814a9100>] ? pid_param_set+0x130/0x130
 [<ffffffff8107df56>] call_timer_fn+0x36/0x110
 [<ffffffff814a9100>] ? pid_param_set+0x130/0x130
 [<ffffffff8107fdcf>] run_timer_softirq+0x21f/0x320
 [<ffffffff81077b2f>] __do_softirq+0xef/0x280
 [<ffffffff816156dc>] call_softirq+0x1c/0x30
 [<ffffffff81015d95>] do_softirq+0x65/0xa0
 [<ffffffff81077ec5>] irq_exit+0x115/0x120
 [<ffffffff81616355>] smp_apic_timer_interrupt+0x45/0x60
 [<ffffffff81614a1d>] apic_timer_interrupt+0x6d/0x80
 <EOI>

 [<ffffffff814a9c32>] ? cpuidle_enter_state+0x52/0xc0
 [<ffffffff814a9c28>] ? cpuidle_enter_state+0x48/0xc0
 [<ffffffff814a9d65>] cpuidle_idle_call+0xc5/0x200
 [<ffffffff8101d14e>] arch_cpu_idle+0xe/0x30
 [<ffffffff810c67c1>] cpu_startup_entry+0xf1/0x290
 [<ffffffff8104228a>] start_secondary+0x1ba/0x230
Code: 42 0f 00 45 89 e6 48 01 c2 43 8d 44 6d 00 39 d0 73 26 49 c1 e5 08 89 d2 4d 63 f4 49 63 c5 48 c1 e2 08 48 c1 e0 08 48 63 ca 48 99 <48> f7 f9 48 98 4c 0f af f0 49 c1 ee 08 8b 43 78 c1 e0 08 44 29
RIP  [<ffffffff814a9279>] intel_pstate_timer_func+0x179/0x3d0
 RSP <ffff883fff4e3db8>

The kernel values for cpudata for CPU 113 were:

struct cpudata {
  cpu = 113,
  timer = {
    entry = {
      next = 0x0,
      prev = 0xdead000000200200
    },
    expires = 8357799745,
    base = 0xffff883fe84ec001,
    function = 0xffffffff814a9100 <intel_pstate_timer_func>,
    data = 18446612406765768960,
<snip>
    i_gain = 0,
    d_gain = 0,
    deadband = 0,
    last_err = 22489
  },
  last_sample_time = {
    tv64 = 4063132438017305
  },
  prev_aperf = 287326796397463,
  prev_mperf = 251427432090198,
  sample = {
    core_pct_busy = 23081,
    aperf = 2937407,
    mperf = 3257884,
    freq = 2524484,
    time = {
      tv64 = 4063149215234118
    }
  }
}

which results in the time between samples = last_sample_time - sample.time
= 4063149215234118 - 4063132438017305 = 16777216813 which is 16.777 seconds.

The duration between reads of the APERF and MPERF registers overflowed a s32
sized integer in intel_pstate_get_scaled_busy()'s call to div_fp().  The result
is that int_tofp(duration_us) == 0, and the kernel attempts to divide by 0.

While the kernel shouldn't be delaying for a long time, it can and does
happen and the intel_pstate driver should not panic in this situation.  This
patch changes the div_fp() function to use div64_s64() to allow for "long"
division.  This will avoid the overflow condition on long delays.

[v2]: use div64_s64() in div_fp()
Signed-off-by: NPrarit Bhargava <prarit@redhat.com>
Signed-off-by: NRafael J. Wysocki <rafael.j.wysocki@intel.com>

This file depends on a Kconfig option which is a bool, so
we use the appropriate registration function, which avoids us
relying on an implicit inclusion of <module.h> which we are
doing currently.

While this currently works, we really don't want to be including
the module.h header in non-modular code, which we'd be forced
to do, pending some upcoming code relocation from init.h into
module.h.  So we fix it now by using the non-modular equivalent.

Cc: "Rafael J. Wysocki" <rjw@rjwysocki.net>
Cc: Viresh Kumar <viresh.kumar@linaro.org>
Acked-by: NViresh Kumar <viresh.kumar@linaro.org>
Cc: Kukjin Kim <kgene@kernel.org>
Cc: linux-pm@vger.kernel.org
Cc: linux-arm-kernel@lists.infradead.org
Signed-off-by: NPaul Gortmaker <paul.gortmaker@windriver.com>

This file is built off of a tristate Kconfig option ("ARM_EXYNOS_CPUFREQ")
and also contains modular function calls so it should explicitly include
module.h to avoid compile breakage during pending header shuffles.

Cc: "Rafael J. Wysocki" <rjw@rjwysocki.net>
Cc: Viresh Kumar <viresh.kumar@linaro.org>
Acked-by: NViresh Kumar <viresh.kumar@linaro.org>
Cc: Kukjin Kim <kgene@kernel.org>
Cc: Krzysztof Kozlowski <k.kozlowski@samsung.com>
Acked-by: NKrzysztof Kozlowski <k.kozlowski@samsung.com>
Cc: linux-pm@vger.kernel.org
Cc: linux-arm-kernel@lists.infradead.org
Cc: linux-samsung-soc@vger.kernel.org
Signed-off-by: NPaul Gortmaker <paul.gortmaker@windriver.com>

Each time the CPU switches its frequency, the clock nodes in
DTS are walked through to find proper clock source. This is
very time-consuming, for example, it is up to 500+ us on T4240.
Besides, switching time varies from clock to clock.
To optimize this, each input clock of CPU is buffered, so that
it can be picked up instantly when needed.

Since for each CPU each input clock is stored in a pointer
which takes 4 or 8 bytes memory and normally there are several
input clocks per CPU, that will not take much memory as well.
Signed-off-by: NTang Yuantian <Yuantian.Tang@freescale.com>
Acked-by: NViresh Kumar <viresh.kumar@linaro.org>
Signed-off-by: NRafael J. Wysocki <rafael.j.wysocki@intel.com>

Signed-off-by: NShailendra Verma <shailendra.capricorn@gmail.com>
Acked-by: NViresh Kumar <viresh.kumar@linaro.org>
Signed-off-by: NRafael J. Wysocki <rafael.j.wysocki@intel.com>

Signed-off-by: NShailendra Verma <shailendra.capricorn@gmail.com>
Acked-by: NViresh Kumar <viresh.kumar@linaro.org>
Signed-off-by: NRafael J. Wysocki <rafael.j.wysocki@intel.com>

There are several races reported in cpufreq core around governors (only
ondemand and conservative) by different people.

There are at least two race scenarios present in governor code:
 (a) Concurrent access/updates of governor internal structures.

 It is possible that fields such as 'dbs_data->usage_count', etc.  are
 accessed simultaneously for different policies using same governor
 structure (i.e. CPUFREQ_HAVE_GOVERNOR_PER_POLICY flag unset). And
 because of this we can dereference bad pointers.

 For example consider a system with two CPUs with separate 'struct
 cpufreq_policy' instances. CPU0 governor: ondemand and CPU1: powersave.
 CPU0 switching to powersave and CPU1 to ondemand:
	CPU0				CPU1

	store*				store*

	cpufreq_governor_exit()		cpufreq_governor_init()
					dbs_data = cdata->gdbs_data;

	if (!--dbs_data->usage_count)
		kfree(dbs_data);

					dbs_data->usage_count++;
					*Bad pointer dereference*

 There are other races possible between EXIT and START/STOP/LIMIT as
 well. Its really complicated.

 (b) Switching governor state in bad sequence:

 For example trying to switch a governor to START state, when the
 governor is in EXIT state. There are some checks present in
 __cpufreq_governor() but they aren't sufficient as they compare events
 against 'policy->governor_enabled', where as we need to take governor's
 state into account, which can be used by multiple policies.

These two issues need to be solved separately and the responsibility
should be properly divided between cpufreq and governor core.

The first problem is more about the governor core, as it needs to
protect its structures properly. And the second problem should be fixed
in cpufreq core instead of governor, as its all about sequence of
events.

This patch is trying to solve only the first problem.

There are two types of data we need to protect,
- 'struct common_dbs_data': No matter what, there is going to be a
  single copy of this per governor.
- 'struct dbs_data': With CPUFREQ_HAVE_GOVERNOR_PER_POLICY flag set, we
  will have per-policy copy of this data, otherwise a single copy.

Because of such complexities, the mutex present in 'struct dbs_data' is
insufficient to solve our problem. For example we need to protect
fetching of 'dbs_data' from different structures at the beginning of
cpufreq_governor_dbs(), to make sure it isn't currently being updated.

This can be fixed if we can guarantee serialization of event parsing
code for an individual governor. This is best solved with a mutex per
governor, and the placeholder for that is 'struct common_dbs_data'.

And so this patch moves the mutex from 'struct dbs_data' to 'struct
common_dbs_data' and takes it at the beginning and drops it at the end
of cpufreq_governor_dbs().

Tested with and without following configuration options:

CONFIG_LOCKDEP_SUPPORT=y
CONFIG_DEBUG_RT_MUTEXES=y
CONFIG_DEBUG_PI_LIST=y
CONFIG_DEBUG_SPINLOCK=y
CONFIG_DEBUG_MUTEXES=y
CONFIG_DEBUG_LOCK_ALLOC=y
CONFIG_PROVE_LOCKING=y
CONFIG_LOCKDEP=y
CONFIG_DEBUG_ATOMIC_SLEEP=y
Signed-off-by: NViresh Kumar <viresh.kumar@linaro.org>
Reviewed-by: NPreeti U Murthy <preeti@linux.vnet.ibm.com>
Signed-off-by: NRafael J. Wysocki <rafael.j.wysocki@intel.com>

cpufreq_governor_dbs() is hardly readable, it is just too big and
complicated. Lets make it more readable by splitting out event specific
routines.

Order of statements is changed at few places, but that shouldn't bring
any functional change.
Signed-off-by: NViresh Kumar <viresh.kumar@linaro.org>
Reviewed-by: NPreeti U Murthy <preeti@linux.vnet.ibm.com>
Signed-off-by: NRafael J. Wysocki <rafael.j.wysocki@intel.com>

Notifiers are required only for conservative governor and the common
governor code is unnecessarily polluted with that. Handle that from
cs_init/exit() instead of cpufreq_governor_dbs().
Signed-off-by: NViresh Kumar <viresh.kumar@linaro.org>
Reviewed-by: NPreeti U Murthy <preeti@linux.vnet.ibm.com>
Signed-off-by: NRafael J. Wysocki <rafael.j.wysocki@intel.com>

cpufreq_update_policy() was kept as a separate routine earlier as it was
handling migration of sysfs directories, which isn't the case anymore.
It is only updating policy->cpu now and is called by a single caller.

The WARN_ON() isn't really required anymore, as we are just updating the
cpu now, not moving the sysfs directories.
Signed-off-by: NViresh Kumar <viresh.kumar@linaro.org>
Signed-off-by: NRafael J. Wysocki <rafael.j.wysocki@intel.com>

__cpufreq_remove_dev_finish() is doing two things today:
- Restarts the governor if some CPUs from concerned policy are still
  online.
- Frees the policy if all CPUs are offline.

The first task of restarting the governor can be moved to
__cpufreq_remove_dev_prepare() to restart the governor early. There is
no race between _prepare() and _finish() as they would be handling
completely different cases. _finish() will only be required if we are
going to free the policy and that has nothing to do with restarting the
governor.
Original-by: NSaravana Kannan <skannan@codeaurora.org>
Signed-off-by: NViresh Kumar <viresh.kumar@linaro.org>
Signed-off-by: NRafael J. Wysocki <rafael.j.wysocki@intel.com>

cpufreq_policy_put_kobj() is actually part of freeing the policy and can
be called from cpufreq_policy_free() directly instead of a separate
call.
Signed-off-by: NViresh Kumar <viresh.kumar@linaro.org>
Signed-off-by: NRafael J. Wysocki <rafael.j.wysocki@intel.com>

policy->kobj is required to be initialized once in the lifetime of a
policy.  Currently we are initializing it from __cpufreq_add_dev() and
that doesn't look to be the best place for doing so as we have to do
this on special cases (like: !recover_policy).

We can initialize it from a more obvious place cpufreq_policy_alloc()
and that will make code look cleaner, specially the error handling part.

The error handling part of __cpufreq_add_dev() was doing almost the same
thing while recover_policy is true or false. Fix that as well by always
calling cpufreq_policy_put_kobj() with an additional parameter to skip
notification part of it.
Signed-off-by: NViresh Kumar <viresh.kumar@linaro.org>
Signed-off-by: NRafael J. Wysocki <rafael.j.wysocki@intel.com>

When we hot-unplug a cpu, we remove its sysfs cpufreq directory and if
the outgoing cpu was the owner of policy->kobj earlier then we migrate
the sysfs directory to under another online cpu.

There are few disadvantages this brings:
- Code Complexity
- Slower hotplug/suspend/resume
- sysfs file permissions are reset after all policy->cpus are offlined
- CPUFreq stats history lost after all policy->cpus are offlined
- Special management of sysfs stuff during suspend/resume

To overcome these, this patch modifies the way sysfs directories are
managed:
- Select sysfs kobjects owner while initializing policy and don't change
  it during hotplugs. Track it with kobj_cpu created earlier.

- Create symlinks for all related CPUs (can be offline) instead of
  affected CPUs on policy initialization and remove them only when the
  policy is freed.

- Free policy structure only on the removal of cpufreq-driver and not
  during hotplug/suspend/resume, detected by checking 'struct
  subsys_interface *' (Valid only when called from
  subsys_interface_unregister() while unregistering driver).

Apart from this, special care is taken to handle physical hoplug of CPUs
as we wouldn't remove sysfs links or remove policies on logical
hotplugs. Physical hotplug happens in the following sequence.

Hot removal:
- CPU is offlined first, ~ 'echo 0 >
  /sys/devices/system/cpu/cpuX/online'
- Then its device is removed along with all sysfs files, cpufreq core
  notified with cpufreq_remove_dev() callback from subsys-interface..

Hot addition:
- First the device along with its sysfs files is added, cpufreq core
  notified with cpufreq_add_dev() callback from subsys-interface..
- CPU is onlined, ~ 'echo 1 > /sys/devices/system/cpu/cpuX/online'

We call the same routines with both hotplug and subsys callbacks, and we
sense physical hotplug with cpu_offline() check in subsys callback. We
can handle most of the stuff with regular hotplug callback paths and
add/remove cpufreq sysfs links or free policy from subsys callbacks.
Original-by: NSaravana Kannan <skannan@codeaurora.org>
Signed-off-by: NViresh Kumar <viresh.kumar@linaro.org>
Signed-off-by: NRafael J. Wysocki <rafael.j.wysocki@intel.com>

Later commits would change the way policies are managed today. Policies
wouldn't be freed on cpu hotplug (currently they aren't freed only for
suspend), and while the CPU is offline, the sysfs cpufreq files would
still be present.

User may accidentally try to update the sysfs files in following
directory: '/sys/devices/system/cpu/cpuX/cpufreq/'. And that would
result in undefined behavior as policy wouldn't be active then.

Apart from updating the store() routine, we also update __cpufreq_get()
which can call cpufreq_out_of_sync(). The later routine tries to update
policy->cur and starts notifying kernel about it.
Signed-off-by: NViresh Kumar <viresh.kumar@linaro.org>
Acked-by: NSaravana Kannan <skannan@codeaurora.org>
Signed-off-by: NRafael J. Wysocki <rafael.j.wysocki@intel.com>

During initialization and exit it is possible that the target pstate
might not actually be set. Furthermore, the result can be that the
driver and the processor are out of synch and, under some conditions,
the driver might never send the processor the proper target pstate.

This patch adds a bypass or do_checks flag to the call to
intel_pstate_set_pstate. If bypass, then specifically bypass clamp
checks and the do not send if it is the same as last time check. If
do_checks, then, and as before, do the current policy clamp checks,
and do not do actual send if the new target is the same as the old.
Signed-off-by: NDoug Smythies <dsmythies@telus.net>
Reported-by: NMarien Zwart <marien.zwart@gmail.com>
Reported-by: NAlex Lochmann <alexander.lochmann@tu-dortmund.de>
Reported-by: NPiotr Ko?aczkowski <pkolaczk@gmail.com>
Reported-by: NClemens Eisserer <linuxhippy@gmail.com>
Tested-by: NMarien Zwart <marien.zwart@gmail.com>
Tested-by: NDoug Smythies <dsmythies@telus.net>
[ rjw: Dropped pointless symbol definitions, rebased ]
Signed-off-by: NRafael J. Wysocki <rafael.j.wysocki@intel.com>

Commit ce717613 (intel_pstate: Turn per cpu printk into pr_debug)
turned per cpu printk into pr_debug.  However, only half of the change
was done, introducing an inconsistency between entry and exit from
driver pstate control.  This patch changes the exit message to pr_debug
also.

The various messages are inconsistent with respect to any identifier
text that can be used to help isolate the desired information from a
huge log.  This patch makes a consistent identifier portion of the
string.

Amends: ce717613 (intel_pstate: Turn per cpu printk into pr_debug)
Signed-off-by: NDoug Smythies <dsmythies@telus.net>
Signed-off-by: NRafael J. Wysocki <rafael.j.wysocki@intel.com>

Nothing in <asm/io.h> uses anything from <linux/vmalloc.h>, so
remove it from there and fix up the resulting build problems
triggered on x86 {64|32}-bit {def|allmod|allno}configs.

The breakages were triggering in places where x86 builds relied
on vmalloc() facilities but did not include <linux/vmalloc.h>
explicitly and relied on the implicit inclusion via <asm/io.h>.

Also add:

  - <linux/init.h> to <linux/io.h>
  - <asm/pgtable_types> to <asm/io.h>

... which were two other implicit header file dependencies.
Suggested-by: NDavid Miller <davem@davemloft.net>
Signed-off-by: NStephen Rothwell <sfr@canb.auug.org.au>
[ Tidied up the changelog. ]
Acked-by: NDavid Miller <davem@davemloft.net>
Acked-by: NTakashi Iwai <tiwai@suse.de>
Acked-by: NViresh Kumar <viresh.kumar@linaro.org>
Acked-by: NVinod Koul <vinod.koul@intel.com>
Cc: Andrew Morton <akpm@linux-foundation.org>
Cc: Anton Vorontsov <anton@enomsg.org>
Cc: Boris Ostrovsky <boris.ostrovsky@oracle.com>
Cc: Colin Cross <ccross@android.com>
Cc: David Vrabel <david.vrabel@citrix.com>
Cc: H. Peter Anvin <hpa@zytor.com>
Cc: Haiyang Zhang <haiyangz@microsoft.com>
Cc: James E.J. Bottomley <JBottomley@odin.com>
Cc: Jaroslav Kysela <perex@perex.cz>
Cc: K. Y. Srinivasan <kys@microsoft.com>
Cc: Kees Cook <keescook@chromium.org>
Cc: Konrad Rzeszutek Wilk <konrad.wilk@oracle.com>
Cc: Kristen Carlson Accardi <kristen@linux.intel.com>
Cc: Len Brown <lenb@kernel.org>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Rafael J. Wysocki <rjw@rjwysocki.net>
Cc: Suma Ramars <sramars@cisco.com>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Tony Luck <tony.luck@intel.com>
Signed-off-by: NIngo Molnar <mingo@kernel.org>

The former duplicates the functionality of the latter but is
neither documented nor arch-independent.
Signed-off-by: NBartosz Golaszewski <bgolaszewski@baylibre.com>
Acked-by: NViresh Kumar <viresh.kumar@linaro.org>
Acked-by: NRafael J. Wysocki <rjw@rjwysocki.net>
Cc: Benoit Cousson <bcousson@baylibre.com>
Cc: Catalin Marinas <catalin.marinas@arm.com>
Cc: Fenghua Yu <fenghua.yu@intel.com>
Cc: Guenter Roeck <linux@roeck-us.net>
Cc: Jean Delvare <jdelvare@suse.de>
Cc: Jonathan Corbet <corbet@lwn.net>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Oleg Drokin <oleg.drokin@intel.com>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Russell King <linux@arm.linux.org.uk>
Cc: Thomas Gleixner <tglx@linutronix.de>
Link: http://lkml.kernel.org/r/1432645896-12588-8-git-send-email-bgolaszewski@baylibre.comSigned-off-by: NIngo Molnar <mingo@kernel.org>

The former duplicate the functionalities of the latter but are
neither documented nor arch-independent.
Signed-off-by: NBartosz Golaszewski <bgolaszewski@baylibre.com>
Acked-by: NViresh Kumar <viresh.kumar@linaro.org>
Acked-by: NRafael J. Wysocki <rjw@rjwysocki.net>
Cc: Benoit Cousson <bcousson@baylibre.com>
Cc: Catalin Marinas <catalin.marinas@arm.com>
Cc: Fenghua Yu <fenghua.yu@intel.com>
Cc: Guenter Roeck <linux@roeck-us.net>
Cc: Jean Delvare <jdelvare@suse.de>
Cc: Jonathan Corbet <corbet@lwn.net>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Oleg Drokin <oleg.drokin@intel.com>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Russell King <linux@arm.linux.org.uk>
Cc: Thomas Gleixner <tglx@linutronix.de>
Link: http://lkml.kernel.org/r/1432645896-12588-7-git-send-email-bgolaszewski@baylibre.comSigned-off-by: NIngo Molnar <mingo@kernel.org>

The former duplicates the functionality of the latter but is
neither documented nor arch-independent.
Signed-off-by: NBartosz Golaszewski <bgolaszewski@baylibre.com>
Acked-by: NViresh Kumar <viresh.kumar@linaro.org>
Acked-by: NRafael J. Wysocki <rjw@rjwysocki.net>
Cc: Benoit Cousson <bcousson@baylibre.com>
Cc: Catalin Marinas <catalin.marinas@arm.com>
Cc: Fenghua Yu <fenghua.yu@intel.com>
Cc: Guenter Roeck <linux@roeck-us.net>
Cc: Jean Delvare <jdelvare@suse.de>
Cc: Jonathan Corbet <corbet@lwn.net>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Oleg Drokin <oleg.drokin@intel.com>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Russell King <linux@arm.linux.org.uk>
Cc: Thomas Gleixner <tglx@linutronix.de>
Link: http://lkml.kernel.org/r/1432645896-12588-6-git-send-email-bgolaszewski@baylibre.comSigned-off-by: NIngo Molnar <mingo@kernel.org>

The former duplicates the functionality of the latter but is
neither documented nor arch-independent.
Signed-off-by: NBartosz Golaszewski <bgolaszewski@baylibre.com>
Acked-by: NViresh Kumar <viresh.kumar@linaro.org>
Acked-by: NRafael J. Wysocki <rjw@rjwysocki.net>
Cc: Benoit Cousson <bcousson@baylibre.com>
Cc: Catalin Marinas <catalin.marinas@arm.com>
Cc: Fenghua Yu <fenghua.yu@intel.com>
Cc: Guenter Roeck <linux@roeck-us.net>
Cc: Jean Delvare <jdelvare@suse.de>
Cc: Jonathan Corbet <corbet@lwn.net>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Oleg Drokin <oleg.drokin@intel.com>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Russell King <linux@arm.linux.org.uk>
Cc: Thomas Gleixner <tglx@linutronix.de>
Link: http://lkml.kernel.org/r/1432645896-12588-5-git-send-email-bgolaszewski@baylibre.comSigned-off-by: NIngo Molnar <mingo@kernel.org>

In order to prepare for the next few commits, that will stop migrating
sysfs files on cpu hotplug, this patch starts managing sysfs-cpu
separately.

The behavior is still the same as we are still migrating sysfs files on
hotplug, later commits would change that.
Signed-off-by: NSaravana Kannan <skannan@codeaurora.org>
Signed-off-by: NViresh Kumar <viresh.kumar@linaro.org>
Signed-off-by: NRafael J. Wysocki <rafael.j.wysocki@intel.com>

Signed-off-by: NShailendra Verma <shailendra.capricorn@gmail.com>
Signed-off-by: NRafael J. Wysocki <rafael.j.wysocki@intel.com>

Later commits would change the way policies are managed today. Policies
wouldn't be freed on cpu hotplug (currently they aren't freed on
suspend), and while the CPU is offline, the sysfs cpufreq files would
still be present.

Because we don't mark policy->governor as NULL, it still contains
pointer of the last used governor. And if the governor is removed, while
all the CPUs of a policy are hotplugged out, this pointer wouldn't be
valid anymore. And if we try to read the 'scaling_governor', etc.  from
sysfs, it will result in kernel OOPs.

To prevent this, mark policy->governor as NULL for all inactive policies
while the governor is removed from kernel.
Signed-off-by: NViresh Kumar <viresh.kumar@linaro.org>
Signed-off-by: NRafael J. Wysocki <rafael.j.wysocki@intel.com>

History of which governor was used last is common to all CPUs within a
policy and maintaining it per-cpu isn't the best approach for sure.

Apart from wasting memory, this also increases the complexity of
managing this data structure as it has to be updated for all CPUs.

To make that somewhat simpler, lets store this information in a new
field 'last_governor' in struct cpufreq_policy and update it on removal
of last cpu of a policy.

As a side-effect it also solves an old problem, consider a system with
two clusters 0 & 1. And there is one policy per cluster.

Cluster 0: CPU0 and 1.
Cluster 1: CPU2 and 3.

 - CPU2 is first brought online, and governor is set to performance
   (default as cpufreq_cpu_governor wasn't set).
 - Governor is changed to ondemand.
 - CPU2 is taken offline and cpufreq_cpu_governor is updated for CPU2.
 - CPU3 is brought online.
 - Because cpufreq_cpu_governor wasn't set for CPU3, the default governor
   performance is picked for CPU3.

This patch fixes the bug as we now have a single variable to update for
policy.
Signed-off-by: NViresh Kumar <viresh.kumar@linaro.org>
Signed-off-by: NRafael J. Wysocki <rafael.j.wysocki@intel.com>

We reach here while adding policy for a CPU and enter into the 'if'
block only if a policy already exists for the CPU.

As cpufreq_cpu_data is set for all policy->related_cpus now, when the
policy is first added, we can use that to find the CPU's policy instead
of traversing the list of all active policies.
Acked-by: NSaravana Kannan <skannan@codeaurora.org>
Signed-off-by: NViresh Kumar <viresh.kumar@linaro.org>
Signed-off-by: NRafael J. Wysocki <rafael.j.wysocki@intel.com>

We can extract the same information from cpufreq_cpu_data as it is also
available for inactive policies now. And so don't need
cpufreq_cpu_data_fallback anymore.

Also add a WARN_ON() for the case where we try to restore from an active
policy.
Acked-by: NSaravana Kannan <skannan@codeaurora.org>
Signed-off-by: NViresh Kumar <viresh.kumar@linaro.org>
Signed-off-by: NRafael J. Wysocki <rafael.j.wysocki@intel.com>

Now that we can check policy->cpus to find if policy is active or not,
we don't need to clean cpufreq_cpu_data and delete policy from the list
on light weight tear down of policies (like in suspend).

To make it consistent and clean, set cpufreq_cpu_data for all related
CPUs when the policy is first created and clean it only while it is
freed.

Also update cpufreq_cpu_get_raw() to check if cpu is part of
policy->cpus mask, so that we don't end up getting policies for offline
CPUs.

In order to make sure that no users of 'policy' are using an inactive
policy, use cpufreq_cpu_get_raw() instead of directly accessing
cpufreq_cpu_data.
Signed-off-by: NViresh Kumar <viresh.kumar@linaro.org>
Signed-off-by: NRafael J. Wysocki <rafael.j.wysocki@intel.com>

policy->cpus is cleared unconditionally now on hotplug-out of a CPU and
it can be checked to know if a policy is active or not. Create helper
routines to iterate over all active/inactive policies, based on
policy->cpus field.

Replace all instances of for_each_policy() with for_each_active_policy()
to make them iterate only for active policies. (We haven't made changes
yet to keep inactive policies in the same list, but that will be
followed in a later patch).
Signed-off-by: NViresh Kumar <viresh.kumar@linaro.org>
Signed-off-by: NRafael J. Wysocki <rafael.j.wysocki@intel.com>

With the addition of switcher code, there's compile-time dependency on
BIG_LITTLE to get arm_big_little driver compiling on ARM64. Since ARM64
will never add support for bL switcher, it's better to remove the
dependency so that the driver can be reused on ARM64 platforms.

This patch adds stubs to remove BIG_LITTLE dependency in the driver.
Signed-off-by: NSudeep Holla <sudeep.holla@arm.com>
Acked-by: NViresh Kumar <viresh.kumar@linaro.org>
Signed-off-by: NRafael J. Wysocki <rafael.j.wysocki@intel.com>

Commit 007bea09 (intel_pstate: Add setting voltage value for
baytrail P states.) introduced byt_set_pstate() with the assumption that
it would always be run by the CPU whose MSR is to be written by it.  It
turns out, however, that is not always the case in practice, so modify
byt_set_pstate() to enforce the MSR write done by it to always happen on
the right CPU.

Fixes: 007bea09 (intel_pstate: Add setting voltage value for baytrail P states.)
Signed-off-by: NJoe Konno <joe.konno@intel.com>
Acked-by: NKristen Carlson Accardi <kristen@linux.intel.com>
Cc: 3.14+ <stable@vger.kernel.org> # 3.14+
Signed-off-by: NRafael J. Wysocki <rafael.j.wysocki@intel.com>