Remove redundant 'AND' with cpu_online_mask as the policy->cpus always
contains only the currently online CPUs.
Suggested-by: Viresh Kumar <viresh.kumar@linaro.org>
Link: https://lore.kernel.org/lkml/20231003050019.a6mcchw2o2z2wkrh@vireshk-i7/
Signed-off-by: Sumit Gupta <sumitg@nvidia.com>
[ Viresh: Fix rebase conflict ]
Signed-off-by: Viresh Kumar <viresh.kumar@linaro.org>
Use reference clock count based loop instead of "udelay()" for
sampling of counters to improve the accuracy of re-generated CPU
frequency. "udelay()" internally calls "WFE" which stops the
counters and results in bigger delta between the last set freq
and the re-generated value from counters. The counter sampling
window used in loop is the minimum number of reference clock
cycles which is known to give a stable value of CPU frequency.
The change also helps to reduce the sampling window from "500us"
to "<50us".
Suggested-by: Antti Miettinen <amiettinen@nvidia.com>
Signed-off-by: Sumit Gupta <sumitg@nvidia.com>
Signed-off-by: Viresh Kumar <viresh.kumar@linaro.org>
Currently, we make SMP call on every frequency set request to get the
physical 'CPU ID' and 'CLUSTER ID' for the target CPU. This change
optimizes the repeated calls by storing the physical IDs and the per
core frequency register offset for all CPUs during boot. Later this
info is used directly when required to set the frequency or read it
from ACTMON counters.
Signed-off-by: Sumit Gupta <sumitg@nvidia.com>
Signed-off-by: Viresh Kumar <viresh.kumar@linaro.org>
Add exit hook and remove OPP table when the device gets unregistered.
This will fix the error messages when the CPU FREQ driver module is
removed and then re-inserted. It also fixes these messages while
onlining the first CPU from a policy whose all CPU's were previously
offlined.
debugfs: File 'cpu5' in directory 'opp' already present!
debugfs: File 'cpu6' in directory 'opp' already present!
debugfs: File 'cpu7' in directory 'opp' already present!
Fixes: f41e1442ac ("cpufreq: tegra194: add OPP support and set bandwidth")
Signed-off-by: Sumit Gupta <sumitg@nvidia.com>
[ Viresh: Dropped irrelevant change from it ]
Signed-off-by: Viresh Kumar <viresh.kumar@linaro.org>
Implement the light-weight tear down and bring up helpers to reduce the
amount of work to do on CPU offline/online operation.
This change helps to make the hotplugging paths much faster.
Suggested-by: Viresh Kumar <viresh.kumar@linaro.org>
Signed-off-by: Sumit Gupta <sumitg@nvidia.com>
Link: https://lore.kernel.org/lkml/20230816033402.3abmugb5goypvllm@vireshk-i7/
[ Viresh: Fixed rebase conflict ]
Signed-off-by: Viresh Kumar <viresh.kumar@linaro.org>
The .remove() callback for a platform driver returns an int which makes
many driver authors wrongly assume it's possible to do error handling by
returning an error code. However the value returned is (mostly) ignored
and this typically results in resource leaks. To improve here there is a
quest to make the remove callback return void. In the first step of this
quest all drivers are converted to .remove_new() which already returns
void.
Trivially convert this driver from always returning zero in the remove
callback to the void returning variant.
Cc: Uwe Kleine-König <u.kleine-koenig@pengutronix.de>
Signed-off-by: Yangtao Li <frank.li@vivo.com>
Signed-off-by: Viresh Kumar <viresh.kumar@linaro.org>
If the probe needs to be deferred, some resources still need to be
released. So branch to the error handling path instead of returning
directly.
Fixes: f41e1442ac ("cpufreq: tegra194: add OPP support and set bandwidth")
Signed-off-by: Christophe JAILLET <christophe.jaillet@wanadoo.fr>
Reviewed-by: Sumit Gupta <sumitg@nvidia.com>
Acked-by: Thierry Reding <treding@nvidia.com>
Signed-off-by: Viresh Kumar <viresh.kumar@linaro.org>
Add support to use OPP table from DT in Tegra194 cpufreq driver.
Tegra SoC's receive the frequency lookup table (LUT) from BPMP-FW.
Cross check the OPP's present in DT against the LUT from BPMP-FW
and enable only those DT OPP's which are present in LUT also.
The OPP table in DT has CPU Frequency to bandwidth mapping where
the bandwidth value is per MC channel. DRAM bandwidth depends on the
number of MC channels which can vary as per the boot configuration.
This per channel bandwidth from OPP table will be later converted by
MC driver to final bandwidth value by multiplying with number of
channels before sending the request to BPMP-FW.
If OPP table is not present in DT, then use the LUT from BPMP-FW
directy as the CPU frequency table and not do the DRAM frequency
scaling which is same as the current behavior.
Now, as the CPU Frequency table is being controlling through OPP
table in DT. Keeping fewer entries in the table will create less
frequency steps and can help to scale fast to high frequencies
when required.
Signed-off-by: Sumit Gupta <sumitg@nvidia.com>
Signed-off-by: Viresh Kumar <viresh.kumar@linaro.org>
Populate the flag CPUFREQ_IS_COOLING_DEV for the Tegra194 CPUFREQ driver
to register it as a cooling device. This enables CPU frequency
throttling for CPUs when the passive trip points are crossed.
Signed-off-by: Yi-Wei Wang <yiweiw@nvidia.com>
Signed-off-by: Jon Hunter <jonathanh@nvidia.com>
Signed-off-by: Viresh Kumar <viresh.kumar@linaro.org>
When the Tegra194 CPUFREQ driver is built as a module it is not
automatically loaded as expected on Tegra194 devices. Populate the
MODULE_DEVICE_TABLE to fix this.
Cc: v5.9+ <stable@vger.kernel.org> # v5.9+
Fixes: df320f8935 ("cpufreq: Add Tegra194 cpufreq driver")
Signed-off-by: Jon Hunter <jonathanh@nvidia.com>
Signed-off-by: Viresh Kumar <viresh.kumar@linaro.org>
tegra239_cpufreq_soc is only used in tegra194-cpufreq.c now, change it
to static.
Fixes: 6768860107 ("cpufreq: tegra194: Add support for Tegra239")
Signed-off-by: Yang Yingliang <yangyingliang@huawei.com>
Signed-off-by: Viresh Kumar <viresh.kumar@linaro.org>
Adding support for Tegra239 SoC which has eight cores in
a single cluster. Also, moving num_clusters to SoC data
to avoid over allocating memory for four clusters always.
Signed-off-by: Sumit Gupta <sumitg@nvidia.com>
Acked-by: Thierry Reding <treding@nvidia.com>
Signed-off-by: Viresh Kumar <viresh.kumar@linaro.org>
Return the value returned by smp_call_function_single() directly instead
of storing it in another redundant variable.
Reported-by: Zeal Robot <zealci@zte.com.cn>
Signed-off-by: ye xingchen <ye.xingchen@zte.com.cn>
[ Viresh: Minor update to commit log ]
Signed-off-by: Viresh Kumar <viresh.kumar@linaro.org>
This patch adds driver support for Tegra234 cpufreq.
Tegra234 has per core MMIO registers instead of system registers for
cpu frequency requests and to read the counters for re-constructing
the cpu frequency. Also, MPIDR affinity info in Tegra234 is different
from Tegra194.
Added ops hooks and soc data for Tegra234. This will help to easily
add variants of Tegra234 and future SoC's which use similar logic to
{get|set} the cpu frequency.
Signed-off-by: Sumit Gupta <sumitg@nvidia.com>
Signed-off-by: Viresh Kumar <viresh.kumar@linaro.org>
Adding SoC data and ops to support multiple SoC's in same driver.
Signed-off-by: Sumit Gupta <sumitg@nvidia.com>
Signed-off-by: Viresh Kumar <viresh.kumar@linaro.org>
The return value from tegra_bpmp_transfer indicates the success or
failure of the IPC transaction with BPMP. If the transaction
succeeded, we also need to check the actual command's result code.
Add code to do this.
While at it, explicitly handle missing CPU clusters, which can
occur on floorswept chips. This worked before as well, but
possibly only by accident.
Signed-off-by: Mikko Perttunen <mperttunen@nvidia.com>
Signed-off-by: Viresh Kumar <viresh.kumar@linaro.org>
During cpufreq driver's registration, if the ->init() callback for all
the CPUs fail then there is not much point in keeping the driver around
as it will only account for more of unnecessary noise, for example
cpufreq core will try to suspend/resume the driver which never got
registered properly.
The removal of such a driver is avoided if the driver carries the
CPUFREQ_STICKY flag. This was added way back [1] in 2004 and perhaps no
one should ever need it now. A lot of drivers do set this flag, probably
because they just copied it from other drivers.
This was added earlier for some platforms [2] because their cpufreq
drivers were getting registered before the CPUs were registered with
subsys framework. And hence they used to fail.
The same isn't true anymore though. The current code flow in the kernel
is:
start_kernel()
-> kernel_init()
-> kernel_init_freeable()
-> do_basic_setup()
-> driver_init()
-> cpu_dev_init()
-> subsys_system_register() //For CPUs
-> do_initcalls()
-> cpufreq_register_driver()
Clearly, the CPUs will always get registered with subsys framework
before any cpufreq driver can get probed. Remove the flag and update the
relevant drivers.
Link: https://git.kernel.org/pub/scm/linux/kernel/git/tglx/history.git/commit/include/linux/cpufreq.h?id=7cc9f0d9a1ab04cedc60d64fd8dcf7df224a3b4d # [1]
Link: https://git.kernel.org/pub/scm/linux/kernel/git/tglx/history.git/commit/arch/arm/mach-sa1100/cpu-sa1100.c?id=f59d3bbe35f6268d729f51be82af8325d62f20f5 # [2]
Signed-off-by: Viresh Kumar <viresh.kumar@linaro.org>
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
The function tegra194_get_speed_common() uses hardware timers to
calculate the current CPUFREQ and so rename this function to be
tegra194_calculate_speed() to reflect what it does.
Signed-off-by: Jon Hunter <jonathanh@nvidia.com>
Signed-off-by: Viresh Kumar <viresh.kumar@linaro.org>
The Tegra194 CPUFREQ driver sets the CPUFREQ_NEED_INITIAL_FREQ_CHECK
flag which means that the CPUFREQ framework will call the 'get' callback
on boot to determine the current frequency of the CPUs. Therefore, it is
not necessary for the Tegra194 CPUFREQ driver to internally call the
tegra194_get_speed_common() during initialisation to query the current
frequency as well. Fix this by removing the call to the
tegra194_get_speed_common() during initialisation and simplify the code.
Signed-off-by: Jon Hunter <jonathanh@nvidia.com>
Signed-off-by: Viresh Kumar <viresh.kumar@linaro.org>
Frequency returned by 'cpuinfo_cur_freq' using counters is not fixed
and keeps changing slightly. This change returns a consistent value
from freq_table. If the reconstructed frequency has acceptable delta
from the last written value, then return the frequency corresponding
to the last written ndiv value from freq_table. Otherwise, print a
warning and return the reconstructed freq.
Signed-off-by: Sumit Gupta <sumitg@nvidia.com>
Signed-off-by: Viresh Kumar <viresh.kumar@linaro.org>
Commit eaecca9e77 ("arm64: Fix __cpu_logical_map undefined issue")
fixes the issue with building tegra194 cpufreq driver as module. But
the fix might cause problem while supporting physical CPU hotplug[1].
This patch fixes the original problem by avoiding use of cpu_logical_map().
Instead calling read_cpuid_mpidr() to get MPIDR on target CPU.
[1] https://lore.kernel.org/linux-arm-kernel/20200724131059.GB6521@bogus/
Fixes: df320f8935 ("cpufreq: Add Tegra194 cpufreq driver")
Reviewed-by: Sudeep Holla <sudeep.holla@arm.com>
Signed-off-by: Sumit Gupta <sumitg@nvidia.com>
Acked-by: Viresh Kumar <viresh.kumar@linaro.org>
[ rjw: Subject & changelog edits ]
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
Add support for CPU frequency scaling on Tegra194. The frequency
of each core can be adjusted by writing a clock divisor value to
a MSR on the core. The range of valid divisors is queried from
the BPMP.
Signed-off-by: Mikko Perttunen <mperttunen@nvidia.com>
Signed-off-by: Sumit Gupta <sumitg@nvidia.com>
Signed-off-by: Viresh Kumar <viresh.kumar@linaro.org>
