Commit Graph

11 Commits

Author SHA1 Message Date
Dmitry Osipenko
bdb1ffdad3 cpuidle: tegra: Check whether PMC is ready
Check whether PMC is ready before proceeding with the cpuidle registration.
This fixes racing with the PMC driver probe order, which results in a
disabled deepest CC6 idling state if cpuidle driver is probed before the
PMC.

Acked-by: Daniel Lezcano <daniel.lezcano@linaro.org>
Signed-off-by: Dmitry Osipenko <digetx@gmail.com>
Signed-off-by: Thierry Reding <treding@nvidia.com>
2021-10-05 19:11:40 +02:00
Dmitry Osipenko
2dabed4777 cpuidle: tegra: Remove do_idle firmware call
The do_idle firmware call is unused by all Tegra SoCs, hence remove it in
order to keep driver's code clean.

Tested-by: Anton Bambura <jenneron@protonmail.com> # TF701 T114
Tested-by: Matt Merhar <mattmerhar@protonmail.com> # Ouya T30
Tested-by: Peter Geis <pgwipeout@gmail.com> # Ouya T30
Signed-off-by: Dmitry Osipenko <digetx@gmail.com>
Reviewed-by: Daniel Lezcano <daniel.lezcano@linaro.org>
Signed-off-by: Daniel Lezcano <daniel.lezcano@linaro.org>
Link: https://lore.kernel.org/r/20210302095405.28453-2-digetx@gmail.com
2021-04-08 19:54:14 +02:00
Dmitry Osipenko
32c8c34d81 cpuidle: tegra: Fix C7 idling state on Tegra114
Trusted Foundation firmware doesn't implement the do_idle call and in
this case suspending should fall back to the common suspend path. In order
to fix this issue we will unconditionally set the NOFLUSH_L2 mode via
firmware call, which is a NO-OP on Tegra30/124, and then proceed to the
C7 idling, like it was done by the older Tegra114 cpuidle driver.

Fixes: 14e086baca ("cpuidle: tegra: Squash Tegra114 driver into the common driver")
Cc: stable@vger.kernel.org # 5.7+
Reported-by: Anton Bambura <jenneron@protonmail.com> # TF701 T114
Tested-by: Anton Bambura <jenneron@protonmail.com> # TF701 T114
Tested-by: Matt Merhar <mattmerhar@protonmail.com> # Ouya T30
Tested-by: Peter Geis <pgwipeout@gmail.com> # Ouya T30
Signed-off-by: Dmitry Osipenko <digetx@gmail.com>
Reviewed-by: Daniel Lezcano <daniel.lezcano@linaro.org>
Signed-off-by: Daniel Lezcano <daniel.lezcano@linaro.org>
Link: https://lore.kernel.org/r/20210302095405.28453-1-digetx@gmail.com
2021-04-08 19:54:14 +02:00
Dmitry Osipenko
c39de538a0 cpuidle: tegra: Annotate tegra_pm_set_cpu_in_lp2() with RCU_NONIDLE
Annotate tegra_pm_set[clear]_cpu_in_lp2() with RCU_NONIDLE in order to
fix lockdep warning about suspicious RCU usage of a spinlock during late
idling phase.

 WARNING: suspicious RCU usage
 ...
 include/trace/events/lock.h:13 suspicious rcu_dereference_check() usage!
 ...
  (dump_stack) from (lock_acquire)
  (lock_acquire) from (_raw_spin_lock)
  (_raw_spin_lock) from (tegra_pm_set_cpu_in_lp2)
  (tegra_pm_set_cpu_in_lp2) from (tegra_cpuidle_enter)
  (tegra_cpuidle_enter) from (cpuidle_enter_state)
  (cpuidle_enter_state) from (cpuidle_enter_state_coupled)
  (cpuidle_enter_state_coupled) from (cpuidle_enter)
  (cpuidle_enter) from (do_idle)
 ...

Tested-by: Peter Geis <pgwipeout@gmail.com>
Reported-by: Peter Geis <pgwipeout@gmail.com>
Signed-off-by: Dmitry Osipenko <digetx@gmail.com>
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
2020-11-16 13:24:32 +01:00
Dmitry Osipenko
1170433e66 cpuidle: tegra: Correctly handle result of arm_cpuidle_simple_enter()
The enter() callback of CPUIDLE drivers returns index of the entered idle
state on success or a negative value on failure. The negative value could
any negative value, i.e. it doesn't necessarily needs to be a error code.
That's because CPUIDLE core only cares about the fact of failure and not
about the reason of the enter() failure.

Like every other enter() callback, the arm_cpuidle_simple_enter() returns
the entered idle-index on success. Unlike some of other drivers, it never
fails. It happened that TEGRA_C1=index=err=0 in the code of cpuidle-tegra
driver, and thus, there is no problem for the cpuidle-tegra driver created
by the typo in the code which assumes that the arm_cpuidle_simple_enter()
returns a error code.

The arm_cpuidle_simple_enter() also may return a -ENODEV error if CPU_IDLE
is disabled in a kernel's config, but all CPUIDLE drivers are disabled if
CPU_IDLE is disabled, including the cpuidle-tegra driver. So we can't ever
see the error code from arm_cpuidle_simple_enter() today.

Of course the code may get some changes in the future and then the
typo may transform into a real bug, so let's correct the typo! The
tegra_cpuidle_state_enter() is now changed to make it return the entered
idle-index on success and negative error code on fail, which puts it on
par with the arm_cpuidle_simple_enter(), making code consistent in regards
to the error handling.

This patch fixes a minor typo in the code, it doesn't fix any bugs.

Signed-off-by: Dmitry Osipenko <digetx@gmail.com>
Reviewed-by: Jon Hunter <jonathanh@nvidia.com>
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
2020-09-21 17:44:54 +02:00
Neal Liu
efe9711214 cpuidle: change enter_s2idle() prototype
Control Flow Integrity(CFI) is a security mechanism that disallows
changes to the original control flow graph of a compiled binary,
making it significantly harder to perform such attacks.

init_state_node() assign same function callback to different
function pointer declarations.

static int init_state_node(struct cpuidle_state *idle_state,
                           const struct of_device_id *matches,
                           struct device_node *state_node) { ...
        idle_state->enter = match_id->data; ...
        idle_state->enter_s2idle = match_id->data; }

Function declarations:

struct cpuidle_state { ...
        int (*enter) (struct cpuidle_device *dev,
                      struct cpuidle_driver *drv,
                      int index);

        void (*enter_s2idle) (struct cpuidle_device *dev,
                              struct cpuidle_driver *drv,
                              int index); };

In this case, either enter() or enter_s2idle() would cause CFI check
failed since they use same callee.

Align function prototype of enter() since it needs return value for
some use cases. The return value of enter_s2idle() is no
need currently.

Signed-off-by: Neal Liu <neal.liu@mediatek.com>
Reviewed-by: Sami Tolvanen <samitolvanen@google.com>
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
2020-07-29 18:38:30 +02:00
Dmitry Osipenko
fafd62e768 cpuidle: tegra: Support CPU cluster power-down state on Tegra30
The new Tegra CPU Idle driver now has a unified code path for the coupled
CC6 (LP2) state, this allows to enable the deepest idling state on Tegra30
SoC where the whole CPU cluster is power-gated.

Tested-by: Michał Mirosław <mirq-linux@rere.qmqm.pl>
Tested-by: Jasper Korten <jja2000@gmail.com>
Tested-by: David Heidelberg <david@ixit.cz>
Tested-by: Peter Geis <pgwipeout@gmail.com>
Signed-off-by: Dmitry Osipenko <digetx@gmail.com>
Signed-off-by: Thierry Reding <treding@nvidia.com>
2020-05-06 18:42:55 +02:00
Dmitry Osipenko
382ac8e22b cpuidle: tegra: Disable CC6 state if LP2 unavailable
LP2 suspending could be unavailable, for example if it is disabled in a
device-tree. CC6 cpuidle state won't work in that case.

Acked-by: Peter De Schrijver <pdeschrijver@nvidia.com>
Acked-by: Daniel Lezcano <daniel.lezcano@linaro.org>
Signed-off-by: Dmitry Osipenko <digetx@gmail.com>
Signed-off-by: Thierry Reding <treding@nvidia.com>
2020-03-13 11:32:01 +01:00
Dmitry Osipenko
14e086baca cpuidle: tegra: Squash Tegra114 driver into the common driver
Tegra20/30/114/124 SoCs have common idling states, thus there is no much
point in having separate drivers for a similar hardware. This patch moves
Tegra114/124 arch/ drivers into the common driver without any functional
changes. The CC6 state is kept disabled on Tegra114/124 because the core
Tegra PM code needs some more work in order to support that state.

Acked-by: Peter De Schrijver <pdeschrijver@nvidia.com>
Signed-off-by: Dmitry Osipenko <digetx@gmail.com>
Acked-by: Daniel Lezcano <daniel.lezcano@linaro.org>
Signed-off-by: Thierry Reding <treding@nvidia.com>
2020-03-13 11:32:01 +01:00
Dmitry Osipenko
19461a499c cpuidle: tegra: Squash Tegra30 driver into the common driver
Tegra20 and Terga30 SoCs have common C1 and CC6 idling states and thus
share the same code paths, there is no point in having separate drivers
for a similar hardware. This patch merely moves functionality of the old
driver into the new, although the CC6 state is kept disabled for now since
old driver had a rudimentary support for this state (allowing to enter
into CC6 only when secondary CPUs are put offline), while new driver can
provide a full-featured support. The new feature will be enabled by
another patch.

Acked-by: Peter De Schrijver <pdeschrijver@nvidia.com>
Tested-by: Peter Geis <pgwipeout@gmail.com>
Tested-by: Jasper Korten <jja2000@gmail.com>
Tested-by: David Heidelberg <david@ixit.cz>
Tested-by: Nicolas Chauvet <kwizart@gmail.com>
Acked-by: Daniel Lezcano <daniel.lezcano@linaro.org>
Signed-off-by: Dmitry Osipenko <digetx@gmail.com>
Signed-off-by: Thierry Reding <treding@nvidia.com>
2020-03-13 11:32:01 +01:00
Dmitry Osipenko
860fbde438 cpuidle: Refactor and move out NVIDIA Tegra20 driver into drivers/cpuidle
The driver's code is refactored in a way that will make it easy to
support Tegra30/114/124 SoCs by this unified driver later on. The
current functionality is equal to the old Tegra20 driver, only the
code's structure changed a tad. This is also a proper platform driver
now.

Acked-by: Peter De Schrijver <pdeschrijver@nvidia.com>
Signed-off-by: Dmitry Osipenko <digetx@gmail.com>
Acked-by: Daniel Lezcano <daniel.lezcano@linaro.org>
Signed-off-by: Thierry Reding <treding@nvidia.com>
2020-03-13 11:31:58 +01:00