The PSCI v1.3 specification adds support for a SYSTEM_OFF2 function
which is analogous to ACPI S4 state. This will allow hosting
environments to determine that a guest is hibernated rather than just
powered off, and handle that state appropriately on subsequent launches.

Since commit 60c0d45a7f7a ("efi/arm64: use UEFI for system reset and
poweroff") the EFI shutdown method is deliberately preferred over PSCI
or other methods. So register a SYS_OFF_MODE_POWER_OFF handler which
*only* handles the hibernation, leaving the original PSCI SYSTEM_OFF as
a last resort via the legacy pm_power_off function pointer.

The hibernation code already exports a system_entering_hibernation()
function which is be used by the higher-priority handler to check for
hibernation. That existing function just returns the value of a static
boolean variable from hibernate.c, which was previously only set in the
hibernation_platform_enter() code path. Set the same flag in the simpler
code path around the call to kernel_power_off() too.

An alternative way to hook SYSTEM_OFF2 into the hibernation code would
be to register a platform_hibernation_ops structure with an ->enter()
method which makes the new SYSTEM_OFF2 call. But that would have the
unwanted side-effect of making hibernation take a completely different
code path in hibernation_platform_enter(), invoking a lot of special dpm
callbacks.

Another option might be to add a new SYS_OFF_MODE_HIBERNATE mode, with
fallback to SYS_OFF_MODE_POWER_OFF. Or to use the sys_off_data to
indicate whether the power off is for hibernation.

But this version works and is relatively simple.

Signed-off-by: David Woodhouse <dwmw@amazon.co.uk>
Acked-by: Rafael J. Wysocki <rafael@kernel.org>
Acked-by: Catalin Marinas <catalin.marinas@arm.com>
Link: https://lore.kernel.org/r/20241019172459.2241939-7-dwmw2@infradead.org
Signed-off-by: Oliver Upton <oliver.upton@linux.dev>

Currently we return the value from invoke_psci_fn() directly as return
value from psci_system_suspend(). It is wrong to send the PSCI interface
return value directly. psci_to_linux_errno() provide the mapping from
PSCI return value to the one that can be returned to the callers within
the kernel.

Use psci_to_linux_errno() to convert and return the correct value from
psci_system_suspend().

Fixes: faf7ec4a92c0 ("drivers: firmware: psci: add system suspend support")
Acked-by: Mark Rutland <mark.rutland@arm.com>
Signed-off-by: Sudeep Holla <sudeep.holla@arm.com>
Link: https://lore.kernel.org/r/20240515095528.1949992-1-sudeep.holla@arm.com
Signed-off-by: Arnd Bergmann <arnd@arndb.de>

On some Qualcomm platforms, like SC8280XP, the attempt to set PC mode
during boot fails with PSCI_RET_DENIED and since commit 998fcd001feb
("firmware/psci: Print a warning if PSCI doesn't accept PC mode") this
is now logged at warning level:

	psci: failed to set PC mode: -3

As there is nothing users can do about the firmware behaving this way,
demote the warning to info level and clearly mark it as a firmware bug:

	psci: [Firmware Bug]: failed to set PC mode: -3

Reviewed-by: Ulf Hansson <ulf.hansson@linaro.org>
Acked-by: Mark Rutland <mark.rutland@arm.com>
Acked-by: Sudeep Holla <sudeep.holla@arm.com>
Signed-off-by: Johan Hovold <johan+linaro@kernel.org>
Acked-by: Dmitry Baryshkov <dmitry.baryshkov@linaro.org>
Signed-off-by: Arnd Bergmann <arnd@arndb.de>

The PSCI suspend code is currently instrumentable, which is not safe as
instrumentation (e.g. ftrace) may try to make use of RCU during idle
periods when RCU is not watching.

To fix this we need to ensure that psci_suspend_finisher() and anything
it calls are not instrumented. We can do this fairly simply by marking
psci_suspend_finisher() and the psci*_cpu_suspend() functions as
noinstr, and the underlying helper functions as __always_inline.

When CONFIG_DEBUG_VIRTUAL=y, __pa_symbol() can expand to an out-of-line
instrumented function, so we must use __pa_symbol_nodebug() within
psci_suspend_finisher().

The raw SMCCC invocation functions are written in assembly, and are not
subject to compiler instrumentation.

Signed-off-by: Mark Rutland <mark.rutland@arm.com>
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Signed-off-by: Ingo Molnar <mingo@kernel.org>
Link: https://lore.kernel.org/r/20230126151323.349423061@infradead.org

Pick up fixes before merging another batch of cpuidle updates.

Signed-off-by: Ingo Molnar <mingo@kernel.org>

The recent cpuidle changes started triggering RCU splats on
Juno development boards:

  | =============================
  | WARNING: suspicious RCU usage
  | -----------------------------
  | include/trace/events/ipi.h:19 suspicious rcu_dereference_check() usage!

Fix cpuidle on ARM64:

 - ... by introducing a new 'is_rcu' flag to the cpuidle helpers & make
   ARM64 use it, as ARM64 wants to keep RCU active longer and wants to
   do the ct_cpuidle_enter()/exit() dance itself.

 - Also update the PSCI driver accordingly.

 - This also removes the last known RCU_NONIDLE() user as a bonus.

Reported-by: Mark Rutland <mark.rutland@arm.com>
Signed-off-by: Peter Zijlstra <peterz@infradead.org>
Signed-off-by: Ingo Molnar <mingo@kernel.org>
Tested-by: Sudeep Holla <sudeep.holla@arm.com>
Tested-by: Mark Rutland <mark.rutland@arm.com>
Reviewed-by: Mark Rutland <mark.rutland@arm.com>
Link: https://lore.kernel.org/r/Y8Z31UbzG3LJgAXE@hirez.programming.kicks-ass.net

--

Contrary to popular belief, PSCI is not a universal property of an
ARM/arm64 system. There is a garden variety of systems out there
that don't (or even cannot) implement it.

I'm the first one deplore such a situation, but hey...

On such systems, a "cat /sys/kernel/debug/psci" results in
fireworks, as no invocation callback is registered.

Check for the invoke_psci_fn and psci_ops.get_version pointers
before registering with the debugfs subsystem, avoiding the
issue altogether.

Fixes: 3137f2e60098 ("firmware/psci: Add debugfs support to ease debugging")
Reported-by: Hector Martin <marcan@marcan.st>
Signed-off-by: Marc Zyngier <maz@kernel.org>
Cc: Dmitry Baryshkov <dmitry.baryshkov@linaro.org>
Cc: Mark Brown <broonie@kernel.org>
Cc: Ulf Hansson <ulf.hansson@linaro.org>
Cc: Arnd Bergmann <arnd@arndb.de>
Cc: Mark Rutland <mark.rutland@arm.com>
Cc: Lorenzo Pieralisi <lpieralisi@kernel.org>
Reviewed-by: Hector Martin <marcan@marcan.st>
Acked-by: Dmitry Baryshkov <dmitry.baryshkov@linaro.org>
Acked-by: Mark Rutland <mark.rutland@arm.com>
Link: https://lore.kernel.org/r/20230105090834.630238-1-maz@kernel.org
Signed-off-by: Will Deacon <will@kernel.org>

Pull ARM driver updates from Arnd Bergmann:
 "The drivers branch for 6.1 is a bit larger than for most releases.

  Most of the changes come from SoC maintainers for the drivers/soc
  subsystem:

   - A new driver for error handling on the NVIDIA Tegra 'control
     backbone' bus.

   - A new driver for Qualcomm LLCC/DDR bandwidth measurement

   - New Rockchip rv1126 and rk3588 power domain drivers

   - DT binding updates for memory controllers, older Rockchip SoCs,
     various Mediatek devices, Qualcomm SCM firmware

   - Minor updates to Hisilicon LPC bus, the Allwinner SRAM driver, the
     Apple rtkit firmware driver, Tegra firmware

   - Minor updates for SoC drivers (Samsung, Mediatek, Renesas, Tegra,
     Qualcomm, Broadcom, NXP, ...)

  There are also some separate subsystem with downstream maintainers
  that merge updates this way:

   - Various updates and new drivers in the memory controller subsystem
     for Mediatek and Broadcom SoCs

   - Small set of changes in preparation to add support for FF-A v1.1
     specification later, in the Arm FF-A firmware subsystem

   - debugfs support in the PSCI firmware subsystem"

* tag 'arm-drivers-6.1' of git://git.kernel.org/pub/scm/linux/kernel/git/soc/soc: (149 commits)
  ARM: remove check for CONFIG_DEBUG_LL_SER3
  firmware/psci: Add debugfs support to ease debugging
  firmware/psci: Print a warning if PSCI doesn't accept PC mode
  dt-bindings: memory: snps,dw-umctl2-ddrc: Extend schema with IRQs/resets/clocks props
  dt-bindings: memory: snps,dw-umctl2-ddrc: Replace opencoded numbers with macros
  dt-bindings: memory: snps,dw-umctl2-ddrc: Use more descriptive device name
  dt-bindings: memory: synopsys,ddrc-ecc: Detach Zynq DDRC controller support
  soc: sunxi: sram: Add support for the D1 system control
  soc: sunxi: sram: Export the LDO control register
  soc: sunxi: sram: Save a pointer to the OF match data
  soc: sunxi: sram: Return void from the release function
  soc: apple: rtkit: Add apple_rtkit_poll
  soc: imx: add i.MX93 media blk ctrl driver
  soc: imx: add i.MX93 SRC power domain driver
  soc: imx: imx8m-blk-ctrl: Use genpd_xlate_onecell
  soc: imx: imx8mp-blk-ctrl: handle PCIe PHY resets
  soc: imx: imx8m-blk-ctrl: add i.MX8MP VPU blk ctrl
  soc: imx: add i.MX8MP HDMI blk ctrl HDCP/HRV_MWR
  soc: imx: add icc paths for i.MX8MP hsio/hdmi blk ctrl
  soc: imx: add icc paths for i.MX8MP media blk ctrl
  ...

To ease debugging of PSCI supported features, add debugfs file called
'psci' describing PSCI and SMC CC versions, enabled features and
options.

Signed-off-by: Dmitry Baryshkov <dmitry.baryshkov@linaro.org>
Reviewed-by: Mark Brown <broonie@kernel.org>
Reviewed-by: Ulf Hansson <ulf.hansson@linaro.org>
Link: https://lore.kernel.org/r/20220926110758.666922-1-dmitry.baryshkov@linaro.org'
Signed-off-by: Arnd Bergmann <arnd@arndb.de>

The function psci_pd_try_set_osi_mode() will print an error if enabling
OSI mode fails. To ease debugging PSCI issues print corresponding
message if switching to PC mode fails too.

Signed-off-by: Dmitry Baryshkov <dmitry.baryshkov@linaro.org>
Reviewed-by: Sudeep Holla <sudeep.holla@arm.com>
Reviewed-by: Ulf Hansson <ulf.hansson@linaro.org>
Acked-by: Mark Rutland <mark.rutland@arm.com>
Link: https://lore.kernel.org/r/20220926110249.666813-1-dmitry.baryshkov@linaro.org'
Signed-off-by: Arnd Bergmann <arnd@arndb.de>