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path: root/drivers/base/power/opp/cpu.c
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2017-10-03PM / OPP: Move the OPP directory out of power/Viresh Kumar
The drivers/base/power/ directory is special and contains code related to power management core like system suspend/resume, hibernation, etc. It was fine to keep the OPP code inside it when we had just one file for it, but it is growing now and already has a directory for itself. Lets move it directly under drivers/ directory, just like cpufreq and cpuidle. Signed-off-by: Viresh Kumar <viresh.kumar@linaro.org> Acked-by: Stephen Boyd <sboyd@codeaurora.org> Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
2017-01-30PM / OPP: Move away from RCU lockingViresh Kumar
The RCU locking isn't well suited for the OPP core. The RCU locking fits better for reader heavy stuff, while the OPP core have at max one or two readers only at a time. Over that, it was getting very confusing the way RCU locking was used with the OPP core. The individual OPPs are mostly well handled, i.e. for an update a new structure was created and then that replaced the older one. But the OPP tables were updated directly all the time from various parts of the core. Though they were mostly used from within RCU locked region, they didn't had much to do with RCU and were governed by the mutex instead. And that mixed with the 'opp_table_lock' has made the core even more confusing. Now that we are already managing the OPPs and the OPP tables with kernel reference infrastructure, we can get rid of RCU locking completely and simplify the code a lot. Remove all RCU references from code and comments. Acquire opp_table->lock while parsing the list of OPPs though. Signed-off-by: Viresh Kumar <viresh.kumar@linaro.org> Reviewed-by: Stephen Boyd <sboyd@codeaurora.org> Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
2017-01-30PM / OPP: Take kref from _find_opp_table()Viresh Kumar
Take reference of the OPP table from within _find_opp_table(). Also update the callers of _find_opp_table() to call dev_pm_opp_put_opp_table() after they have used the OPP table. Note that _find_opp_table() increments the reference under the opp_table_lock. Now that the OPP table wouldn't get freed until the callers of _find_opp_table() call dev_pm_opp_put_opp_table(), there is no need to take the opp_table_lock or rcu_read_lock() around it. Drop them. Signed-off-by: Viresh Kumar <viresh.kumar@linaro.org> Reviewed-by: Stephen Boyd <sboyd@codeaurora.org> Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
2017-01-30PM / OPP: Update OPP users to put referenceViresh Kumar
This patch updates dev_pm_opp_find_freq_*() routines to get a reference to the OPPs returned by them. Also updates the users of dev_pm_opp_find_freq_*() routines to call dev_pm_opp_put() after they are done using the OPPs. As it is guaranteed the that OPPs wouldn't get freed while being used, the RCU read side locking present with the users isn't required anymore. Drop it as well. This patch also updates all users of devfreq_recommended_opp() which was returning an OPP received from the OPP core. Note that some of the OPP core routines have gained rcu_read_{lock|unlock}() calls, as those still use RCU specific APIs within them. Signed-off-by: Viresh Kumar <viresh.kumar@linaro.org> Reviewed-by: Chanwoo Choi <cw00.choi@samsung.com> [Devfreq] Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
2016-06-16PM / OPP: Add 'UNKNOWN' status for shared_opp in struct opp_tableViresh Kumar
dev_pm_opp_get_sharing_cpus() returns 0 even in the case when the OPP core doesn't know whether or not the table is shared. It works on the majority of platforms, where the OPP table is never created before invoking the function and then -ENODEV is returned by it. But in the case of one platform (Jetson TK1) at least, the situation is a bit different. The OPP table has been created (somehow) before dev_pm_opp_get_sharing_cpus() is called and it returns 0. Its caller treats that as 'the CPUs don't share OPPs' and that leads to degraded performance. Fix this by converting 'shared_opp' in struct opp_table to an enum and making dev_pm_opp_get_sharing_cpus() return -EINVAL in case when the value of that field is "access unknown", so that the caller can handle it accordingly (cpufreq-dt considers that as 'all CPUs share the table', for example). Fixes: 6f707daa3833 "PM / OPP: Add dev_pm_opp_get_sharing_cpus()" Reported-and-tested-by: Alexandre Courbot <acourbot@nvidia.com> Signed-off-by: Viresh Kumar <viresh.kumar@linaro.org> [ rjw : Subject & changelog ] Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
2016-05-06PM / OPP: Move CONFIG_OF dependent code in a separate fileViresh Kumar
Recently, a few issues were noticed in the code where CONFIG_OF wasn't consistently used for many routines. The core file is big enough now and ifdef hackery makes it less readable. Move OF-specific code to another file and compile that only if CONFIG_OF is enabled. Compile-tested: - For ARM (exynos) with CONFIG_OF enabled - For X86 with CONFIG_OF disabled (have to enable CONFIG_PM_OPP separately) No functional changes. Signed-off-by: Viresh Kumar <viresh.kumar@linaro.org> Tested-by: Sudeep Holla <sudeep.holla@arm.com> Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
2016-05-05PM / OPP: add non-OF versions of dev_pm_opp_{cpumask_, }remove_tableSudeep Holla
Functions dev_pm_opp_of_{cpumask_,}remove_table removes/frees all the static OPP entries associated with the device and/or all cpus(in case of cpumask) that are created from DT. However the OPP entries are populated reading from the firmware or some different method using dev_pm_opp_add are marked dynamic and can't be removed using above functions. This patch adds non DT/OF versions of dev_pm_opp_{cpumask_,}remove_table to support the above mentioned usecase. This is in preparation to make use of the same in scpi-cpufreq.c Signed-off-by: Sudeep Holla <sudeep.holla@arm.com> Acked-by: Viresh Kumar <viresh.kumar@linaro.org> Reviewed-by: Stephen Boyd <sboyd@codeaurora.org> Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
2016-05-05PM / OPP: pass cpumask by referenceArnd Bergmann
The new use of dev_pm_opp_set_sharing_cpus resulted in a harmless compiler warning with CONFIG_CPUMASK_OFFSTACK=y: drivers/cpufreq/mvebu-cpufreq.c: In function 'armada_xp_pmsu_cpufreq_init': include/linux/cpumask.h:550:25: error: passing argument 2 of 'dev_pm_opp_set_sharing_cpus' discards 'const' qualifier from pointer target type [-Werror=discarded-qualifiers] The problem here is that cpumask_var_t gets passed by reference, but by declaring a 'const cpumask_var_t' argument, only the pointer is constant, not the actual mask. This is harmless because the function does not actually modify the mask. This patch changes the function prototypes for all of the related functions to pass a 'struct cpumask *' instead of 'cpumask_var_t', matching what most other such functions do in the kernel. This lets us mark all the other similar functions as taking a 'const' mask where possible, and it avoids the warning without any change in object code. Signed-off-by: Arnd Bergmann <arnd@arndb.de> Fixes: 947bd567f7a5 (mvebu: Use dev_pm_opp_set_sharing_cpus() to mark OPP tables as shared) Acked-by: Pavel Machek <pavel@ucw.cz> Acked-by: Viresh Kumar <viresh.kumar@linaro.org> Reviewed-by: Stephen Boyd <sboyd@codeaurora.org> Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
2016-04-28PM / OPP: Add dev_pm_opp_get_sharing_cpus()Viresh Kumar
OPP core allows a platform to mark OPP table as shared, when the platform isn't using operating-points-v2 bindings. And, so there should be a non DT way of finding out if the OPP table is shared or not. This patch adds dev_pm_opp_get_sharing_cpus(), which first tries to get OPP sharing information from the opp-table (in case it is already marked as shared), otherwise it uses the existing DT way of finding sharing information. Signed-off-by: Viresh Kumar <viresh.kumar@linaro.org> Acked-by: Arnd Bergmann <arnd@arndb.de> Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
2016-04-28PM / OPP: Mark cpumask as const in dev_pm_opp_set_sharing_cpus()Viresh Kumar
dev_pm_opp_set_sharing_cpus() isn't supposed to update the cpumask passed as its parameter, and so it should always have been marked 'const'. Do it now. Signed-off-by: Viresh Kumar <viresh.kumar@linaro.org> Acked-by: Arnd Bergmann <arnd@arndb.de> Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
2016-04-25PM / OPP: Mark shared-opp for non-dt caseViresh Kumar
opp core allows OPPs to be explicitly marked as shared from platform code, in case of operating-point v1 bindings. Though we do everything fine in that case, we don't set the flag in the opp-table to indicate that the OPPs are shared. It works fine today as the flag isn't used anywhere else in the core, but we should be doing the right thing by marking it set. Signed-off-by: Viresh Kumar <viresh.kumar@linaro.org> Reviewed-by: Stephen Boyd <sboyd@codeaurora.org> Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
2016-04-25PM / OPP: Relocate dev_pm_opp_set_sharing_cpus()Viresh Kumar
Move dev_pm_opp_set_sharing_cpus() towards the end of the file. This is required for better readability after the next patch is applied, which adds dev_pm_opp_get_sharing_cpus(). Signed-off-by: Viresh Kumar <viresh.kumar@linaro.org> Reviewed-by: Stephen Boyd <sboyd@codeaurora.org> Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
2016-04-25PM / OPP: Add missing doc style commentsViresh Kumar
Few of the routines in cpu.c were missing these, add them. Signed-off-by: Viresh Kumar <viresh.kumar@linaro.org> Reviewed-by: Stephen Boyd <sboyd@codeaurora.org> Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
2016-04-25PM / OPP: Propagate the error returned by _find_opp_table()Viresh Kumar
Don't send -EINVAL and propagate what's received from _find_opp_table(). Signed-off-by: Viresh Kumar <viresh.kumar@linaro.org> Reviewed-by: Stephen Boyd <sboyd@codeaurora.org> Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
2016-02-21PM / OPP: Rename structures for clarityViresh Kumar
Stephen pointed out recently, that few structures always confuse him as they aren't named properly. And this patch tries to address that: Names are updated as: - device_opp or dev_opp -> opp_table - dev_opp_list -> opp_tables - dev_opp_list_lock -> opp_table_lock - device_list_opp -> opp_device (it was never a list, but a structure) - list_dev -> opp_dev - And similar changes in comments and function names as well. This also fixes checkpatch warnings that were generated with this patch. No functional changes. Suggested-by: Stephen Boyd <sboyd@codeaurora.org> Signed-off-by: Viresh Kumar <viresh.kumar@linaro.org> Reviewed-by: Stephen Boyd <sboyd@codeaurora.org> Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
2016-01-02PM / OPP: Set cpu_dev->id in cpumask firstPi-Cheng Chen
Set cpu_dev->id in cpumask first when setting up cpumask for CPUs that share the same OPP table. This might be helpful when handling cpumask without the original CPU bitfield set. Signed-off-by: Pi-Cheng Chen <pi-cheng.chen@linaro.org> Acked-by: Viresh Kumar <viresh.kumar@linaro.org> Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
2015-11-06PM / OPP: Protect updates to list_dev with mutexViresh Kumar
dev_opp_list_lock is used everywhere to protect device and OPP lists, but dev_pm_opp_set_sharing_cpus() is missed somehow. And instead we used rcu-lock, which wouldn't help here as we are adding a new list_dev. This also fixes a problem where we have called kzalloc(..., GFP_KERNEL) from within rcu-lock, which isn't allowed as kzalloc can sleep when called with GFP_KERNEL. With CONFIG_DEBUG_ATOMIC_SLEEP set, we get following lockdep-splat: include/linux/rcupdate.h:578 Illegal context switch in RCU read-side critical section! other info that might help us debug this: rcu_scheduler_active = 1, debug_locks = 0 5 locks held by swapper/0/1: #0: (&dev->mutex){......}, at: [<c02f68f4>] __driver_attach+0x48/0x98 #1: (&dev->mutex){......}, at: [<c02f6904>] __driver_attach+0x58/0x98 #2: (cpu_hotplug.lock){++++++}, at: [<c00249d0>] get_online_cpus+0x40/0xb0 #3: (subsys mutex#5){+.+.+.}, at: [<c02f4f8c>] subsys_interface_register+0x44/0xdc #4: (rcu_read_lock){......}, at: [<c0305c80>] dev_pm_opp_set_sharing_cpus+0x0/0x1e4 stack backtrace: CPU: 1 PID: 1 Comm: swapper/0 Tainted: G W 4.3.0-rc7-00047-g81f5932958a8 #59 Hardware name: SAMSUNG EXYNOS (Flattened Device Tree) [<c0016874>] (unwind_backtrace) from [<c001355c>] (show_stack+0x10/0x14) [<c001355c>] (show_stack) from [<c022553c>] (dump_stack+0x94/0xbc) [<c022553c>] (dump_stack) from [<c004904c>] (___might_sleep+0x24c/0x298) [<c004904c>] (___might_sleep) from [<c00f07e4>] (kmem_cache_alloc+0xe8/0x164) [<c00f07e4>] (kmem_cache_alloc) from [<c0305354>] (_add_list_dev+0x30/0x58) [<c0305354>] (_add_list_dev) from [<c0305d50>] (dev_pm_opp_set_sharing_cpus+0xd0/0x1e4) [<c0305d50>] (dev_pm_opp_set_sharing_cpus) from [<c040eda4>] (cpufreq_init+0x4cc/0x62c) [<c040eda4>] (cpufreq_init) from [<c040a964>] (cpufreq_online+0xbc/0x73c) [<c040a964>] (cpufreq_online) from [<c02f4fe0>] (subsys_interface_register+0x98/0xdc) [<c02f4fe0>] (subsys_interface_register) from [<c040a640>] (cpufreq_register_driver+0x110/0x17c) [<c040a640>] (cpufreq_register_driver) from [<c040ef64>] (dt_cpufreq_probe+0x60/0x8c) [<c040ef64>] (dt_cpufreq_probe) from [<c02f8084>] (platform_drv_probe+0x44/0xa4) [<c02f8084>] (platform_drv_probe) from [<c02f67c0>] (driver_probe_device+0x208/0x2f4) [<c02f67c0>] (driver_probe_device) from [<c02f6940>] (__driver_attach+0x94/0x98) [<c02f6940>] (__driver_attach) from [<c02f4c1c>] (bus_for_each_dev+0x68/0x9c) Reported-by: Michael Turquette <mturquette@baylibre.com> Reviewed-by: Stephen Boyd <sboyd@codeaurora.org> Signed-off-by: Viresh Kumar <viresh.kumar@linaro.org> Cc: 4.3 <stable@vger.kernel.org> # 4.3 Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
2015-11-06PM / OPP: Propagate error properly from dev_pm_opp_set_sharing_cpus()Viresh Kumar
We are returning 0 even in case of errors, fix it. Fixes: 8d4d4e98acd6 ("PM / OPP: Add helpers for initializing CPU OPPs") Reported-by: Dan Carpenter <dan.carpenter@oracle.com> Reviewed-by: Stephen Boyd <sboyd@codeaurora.org> Signed-off-by: Viresh Kumar <viresh.kumar@linaro.org> Cc: 4.3 <stable@vger.kernel.org> # 4.3 Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
2015-11-02PM / OPP: Improve print messages with pr_fmtViresh Kumar
To identify OPP core's print messages easily, prefix them with KBUILD_MODNAME. Signed-off-by: Viresh Kumar <viresh.kumar@linaro.org> Reviewed-by: Stephen Boyd <sboyd@codeaurora.org> Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
2015-10-09PM / OPP: passing NULL to PTR_ERR()Dan Carpenter
The code was using PTR_ERR(NULL) which causes a static checker warning. I have fixed up the printks and changed the return to -ENOENT. Signed-off-by: Dan Carpenter <dan.carpenter@oracle.com> Acked-by: Viresh Kumar <viresh.kumar@linaro.org> Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
2015-09-15PM / OPP: Move cpu specific code to opp/cpu.cViresh Kumar
Move cpu device specific code out of generic opp library, and add it to cpu.c. Along with that, create a core-internal opp.h header, which will be used to share structures and function prototypes within opp core. Reviewed-by: Stephen Boyd <sboyd@codeaurora.org> Signed-off-by: Viresh Kumar <viresh.kumar@linaro.org> Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
2015-09-15PM / OPP: Move opp core to its own directoryViresh Kumar
OPP code is expanding and is already present in multiple directories (cpufreq and power). Lets move it to its own directory, to manage it better. This also moves/renames the cpufreq_opp file to cpu.c, as it will contain helpers for cpu device. Its not just about cpufreq, other frameworks can use OPPs as well. Reviewed-by: Stephen Boyd <sboyd@codeaurora.org> Signed-off-by: Viresh Kumar <viresh.kumar@linaro.org> Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>