Make it possible to retrieve a copy of the psci_0_1_function_ids struct.
This is useful for KVM if it is configured to intercept host's PSCI SMCs.

Signed-off-by: David Brazdil <dbrazdil@google.com>
Signed-off-by: Marc Zyngier <maz@kernel.org>
Acked-by: Mark Rutland <mark.rutland@arm.com>
Link: https://lore.kernel.org/r/20201202184122.26046-7-dbrazdil@google.com

Small refactor that replaces array of v0.1 function IDs indexed by an
enum of function-name constants with a struct of function IDs "indexed"
by field names. This is done in preparation for exposing the IDs to
other parts of the kernel. Exposing a struct avoids the need for
bounds checking.

Signed-off-by: David Brazdil <dbrazdil@google.com>
Signed-off-by: Marc Zyngier <maz@kernel.org>
Acked-by: Mark Rutland <mark.rutland@arm.com>
Link: https://lore.kernel.org/r/20201202184122.26046-6-dbrazdil@google.com

Refactor implementation of v0.1+ functions (CPU_SUSPEND, CPU_OFF,
CPU_ON, MIGRATE) to have two functions psci_0_1_foo / psci_0_2_foo that
select the function ID and call a common helper __psci_foo.

This is a small cleanup so that the function ID array is only used for
v0.1 configurations.

Signed-off-by: David Brazdil <dbrazdil@google.com>
Signed-off-by: Marc Zyngier <maz@kernel.org>
Acked-by: Mark Rutland <mark.rutland@arm.com>
Link: https://lore.kernel.org/r/20201202184122.26046-5-dbrazdil@google.com

KVM's host PSCI SMC filter needs to be aware of the PSCI version of the
system but currently it is impossible to distinguish between v0.1 and
PSCI disabled because both have get_version == NULL.

Populate get_version for v0.1 with a function that returns a constant.

psci_opt.get_version is currently unused so this has no effect on
existing functionality.

Signed-off-by: David Brazdil <dbrazdil@google.com>
Signed-off-by: Marc Zyngier <maz@kernel.org>
Acked-by: Mark Rutland <mark.rutland@arm.com>
Link: https://lore.kernel.org/r/20201202184122.26046-4-dbrazdil@google.com

The current user (cpuidle-psci) of psci_set_osi_mode() only needs to enable
the PSCI OSI mode. Although, as subsequent changes shows, there is a need
to be able to reset back into the PSCI PC mode.

Therefore, let's extend psci_set_osi_mode() to take a bool as in-parameter,
to let the user indicate whether to enable OSI or to switch back to PC
mode.

Reviewed-by: Sudeep Holla <sudeep.holla@arm.com>
Signed-off-by: Ulf Hansson <ulf.hansson@linaro.org>
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>

Pull sched/fifo updates from Ingo Molnar:
 "This adds the sched_set_fifo*() encapsulation APIs to remove static
  priority level knowledge from non-scheduler code.

  The three APIs for non-scheduler code to set SCHED_FIFO are:

   - sched_set_fifo()
   - sched_set_fifo_low()
   - sched_set_normal()

  These are two FIFO priority levels: default (high), and a 'low'
  priority level, plus sched_set_normal() to set the policy back to
  non-SCHED_FIFO.

  Since the changes affect a lot of non-scheduler code, we kept this in
  a separate tree"

* tag 'sched-fifo-2020-08-04' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip: (24 commits)
  sched,tracing: Convert to sched_set_fifo()
  sched: Remove sched_set_*() return value
  sched: Remove sched_setscheduler*() EXPORTs
  sched,psi: Convert to sched_set_fifo_low()
  sched,rcutorture: Convert to sched_set_fifo_low()
  sched,rcuperf: Convert to sched_set_fifo_low()
  sched,locktorture: Convert to sched_set_fifo()
  sched,irq: Convert to sched_set_fifo()
  sched,watchdog: Convert to sched_set_fifo()
  sched,serial: Convert to sched_set_fifo()
  sched,powerclamp: Convert to sched_set_fifo()
  sched,ion: Convert to sched_set_normal()
  sched,powercap: Convert to sched_set_fifo*()
  sched,spi: Convert to sched_set_fifo*()
  sched,mmc: Convert to sched_set_fifo*()
  sched,ivtv: Convert to sched_set_fifo*()
  sched,drm/scheduler: Convert to sched_set_fifo*()
  sched,msm: Convert to sched_set_fifo*()
  sched,psci: Convert to sched_set_fifo*()
  sched,drbd: Convert to sched_set_fifo*()
  ...

The return value of down_and_up_cpus() can be assigned to @err directly.
With that, the useless assignment to @err with zero can be dropped.

Signed-off-by: Gavin Shan <gshan@redhat.com>
Reviewed-by: Sudeep Holla <sudeep.holla@arm.com>
Link: https://lore.kernel.org/r/20200630075943.203954-1-gshan@redhat.com
Signed-off-by: Will Deacon <will@kernel.org>

The CPU mask (@tmp) should be released on failing to allocate
@cpu_groups or any of its elements. Otherwise, it leads to memory
leakage because the CPU mask variable is dynamically allocated
when CONFIG_CPUMASK_OFFSTACK is enabled.

Signed-off-by: Gavin Shan <gshan@redhat.com>
Reviewed-by: Sudeep Holla <sudeep.holla@arm.com>
Link: https://lore.kernel.org/r/20200630075227.199624-1-gshan@redhat.com
Signed-off-by: Will Deacon <will@kernel.org>

Ingo suggested that since the new sched_set_*() functions are
implemented using the 'nocheck' variants, they really shouldn't ever
fail, so remove the return value.

Cc: axboe@kernel.dk
Cc: daniel.lezcano@linaro.org
Cc: sudeep.holla@arm.com
Cc: airlied@redhat.com
Cc: broonie@kernel.org
Cc: paulmck@kernel.org
Suggested-by: Ingo Molnar <mingo@kernel.org>
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Reviewed-by: Ingo Molnar <mingo@kernel.org>

Because SCHED_FIFO is a broken scheduler model (see previous patches)
take away the priority field, the kernel can't possibly make an
informed decision.

Effectively changes prio from 99 to 50.

XXX this thing is horrific, it basically open-codes a stop-machine and
idle.

Cc: daniel.lezcano@linaro.org
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Reviewed-by: Ingo Molnar <mingo@kernel.org>
Acked-by: Valentin Schneider <valentin.schneider@arm.com>
Tested-by: Sudeep Holla <sudeep.holla@arm.com>