Ensure that inX() provides the same ordering guarantees as readX()
by hooking up __io_par() so that it maps directly to __iormb().
Reported-by: Andrew Murray <andrew.murray@arm.com>
Reviewed-by: Palmer Dabbelt <palmer@sifive.com>
Signed-off-by: Will Deacon <will.deacon@arm.com>
Signed-off-by: Catalin Marinas <catalin.marinas@arm.com>

The definitions of the __io_[p]ar() macros in asm-generic/io.h take the
value returned by the preceding I/O read as an argument so that
architectures can use this to create order with a subsequent delayX()
routine using a dependency.

Update the riscv barrier definitions to match, although the argument
is currently unused.
Suggested-by: Arnd Bergmann <arnd@arndb.de>
Reviewed-by: Palmer Dabbelt <palmer@sifive.com>
Signed-off-by: Will Deacon <will.deacon@arm.com>
Signed-off-by: Catalin Marinas <catalin.marinas@arm.com>

The inX() and readX() I/O accessors must enforce ordering against
subsequent calls to the delay() routines, so that a read-back from a
device can be used to postpone a subsequent write to the same device.

On some architectures, including arm64, this ordering can only be
achieved by creating a dependency on the value returned by the I/O
accessor operation, so we need to pass the value we read to the
__io_par() and __io_ar() macros in these cases.
Acked-by: Arnd Bergmann <arnd@arndb.de>
Reported-by: Andrew Murray <andrew.murray@arm.com>
Reviewed-by: Palmer Dabbelt <palmer@sifive.com>
Signed-off-by: Will Deacon <will.deacon@arm.com>
Signed-off-by: Catalin Marinas <catalin.marinas@arm.com>

On the Fujitsu-A64FX cores ver(1.0, 1.1), memory access may cause
an undefined fault (Data abort, DFSC=0b111111). This fault occurs under
a specific hardware condition when a load/store instruction performs an
address translation. Any load/store instruction, except non-fault access
including Armv8 and SVE might cause this undefined fault.

The TCR_ELx.NFD1 bit is used by the kernel when CONFIG_RANDOMIZE_BASE
is enabled to mitigate timing attacks against KASLR where the kernel
address space could be probed using the FFR and suppressed fault on
SVE loads.

Since this erratum causes spurious exceptions, which may corrupt
the exception registers, we clear the TCR_ELx.NFDx=1 bits when
booting on an affected CPU.
Signed-off-by: Zhang Lei <zhang.lei@jp.fujitsu.com>
[Generated MIDR value/mask for __cpu_setup(), removed spurious-fault handler
 and always disabled the NFDx bits on affected CPUs]
Signed-off-by: James Morse <james.morse@arm.com>
Tested-by: zhang.lei <zhang.lei@jp.fujitsu.com>
Signed-off-by: Catalin Marinas <catalin.marinas@arm.com>

The assembly macro get_thread_info() actually returns a task_struct and is
analogous to the current/get_current macro/function.

While it could be argued that thread_info sits at the start of
task_struct and the intention could have been to return a thread_info,
instances of loads from/stores to the address obtained from
get_thread_info() use offsets that are generated with
offsetof(struct task_struct, [...]).

Rename get_thread_info() to state it returns a task_struct.
Acked-by: Mark Rutland <mark.rutland@arm.com>
Signed-off-by: Julien Thierry <julien.thierry@arm.com>
Cc: Will Deacon <will.deacon@arm.com>
Signed-off-by: Catalin Marinas <catalin.marinas@arm.com>

TIF_USEDFPU is not defined as thread flags for Arm64. So drop it from
the documentation.
Acked-by: Will Deacon <will.deacon@arm.com>
Signed-off-by: Julien Grall <julien.grall@arm.com>
Cc: linux-arm-kernel@lists.infradead.org
Signed-off-by: Catalin Marinas <catalin.marinas@arm.com>

* 'for-next/perf' of git://git.kernel.org/pub/scm/linux/kernel/git/will/linux:
  perf: xgene: Remove set but not used variable 'config'
  arm64: perf: remove misleading comment
  dt-bindings: arm: Convert PMU binding to json-schema

Clang complains when passing asm operands that are smaller than the
registers they are mapped to:

arch/arm64/include/asm/irqflags.h:50:10: warning: value size does not
	match register size specified by the constraint and modifier
	[-Wasm-operand-widths]
                : "r" (GIC_PRIO_IRQON)

Fix it by casting the affected input operands to a type of the correct
size.
Reported-by: Nathan Chancellor <natechancellor@gmail.com>
Tested-by: Nathan Chancellor <natechancellor@gmail.com>
Signed-off-by: Julien Thierry <julien.thierry@arm.com>
Signed-off-by: Catalin Marinas <catalin.marinas@arm.com>

Add a build option and a command line parameter to build and enable the
support of pseudo-NMIs.
Signed-off-by: Julien Thierry <julien.thierry@arm.com>
Suggested-by: Daniel Thompson <daniel.thompson@linaro.org>
Cc: Will Deacon <will.deacon@arm.com>
Signed-off-by: Catalin Marinas <catalin.marinas@arm.com>

When an NMI is raised while interrupts where disabled, the IRQ tracing
already is in the correct state (i.e. hardirqs_off) and should be left
as such when returning to the interrupted context.

Check whether PMR was masking interrupts when the NMI was raised and
skip IRQ tracing if necessary.
Signed-off-by: Julien Thierry <julien.thierry@arm.com>
Acked-by: Marc Zyngier <marc.zyngier@arm.com>
Cc: Will Deacon <will.deacon@arm.com>
Cc: Marc Zyngier <marc.zyngier@arm.com>
Signed-off-by: Catalin Marinas <catalin.marinas@arm.com>

Handling of an NMI should not set any TIF flags. For NMIs received from
EL0 the current exit path is safe to use.

However, an NMI received at EL1 could have interrupted some task context
that has set the TIF_NEED_RESCHED flag. Preempting a task should not
happen as a result of an NMI.

Skip preemption after handling an NMI from EL1.
Signed-off-by: Julien Thierry <julien.thierry@arm.com>
Acked-by: Marc Zyngier <marc.zyngier@arm.com>
Cc: Will Deacon <will.deacon@arm.com>
Cc: Marc Zyngier <marc.zyngier@arm.com>
Signed-off-by: Catalin Marinas <catalin.marinas@arm.com>

Per definition of the daifflags, Serrors can occur during any interrupt
context, that includes NMI contexts. Trying to nmi_enter in an nmi context
will crash.

Skip nmi_enter/nmi_exit when serror occurred during an NMI.
Suggested-by: James Morse <james.morse@arm.com>
Signed-off-by: Julien Thierry <julien.thierry@arm.com>
Acked-by: Marc Zyngier <marc.zyngier@arm.com>
Cc: Will Deacon <will.deacon@arm.com>
Cc: Mark Rutland <mark.rutland@arm.com>
Cc: Dave Martin <dave.martin@arm.com>
Cc: James Morse <james.morse@arm.com>
Signed-off-by: Catalin Marinas <catalin.marinas@arm.com>

Implement NMI callbacks for GICv3 irqchip. Install NMI safe handlers
when setting up interrupt line as NMI.

Only SPIs and PPIs are allowed to be set up as NMI.
Signed-off-by: Julien Thierry <julien.thierry@arm.com>
Reviewed-by: Marc Zyngier <marc.zyngier@arm.com>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Jason Cooper <jason@lakedaemon.net>
Cc: Marc Zyngier <marc.zyngier@arm.com>
Signed-off-by: Catalin Marinas <catalin.marinas@arm.com>

Provide a higher priority to be used for pseudo-NMIs. When such an
interrupt is received, keep interrupts fully disabled at CPU level to
prevent receiving other pseudo-NMIs while handling the current one.
Signed-off-by: Julien Thierry <julien.thierry@arm.com>
Acked-by: Marc Zyngier <marc.zyngier@arm.com>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Jason Cooper <jason@lakedaemon.net>
Cc: Marc Zyngier <marc.zyngier@arm.com>
Signed-off-by: Catalin Marinas <catalin.marinas@arm.com>

The values non secure EL1 needs to use for PMR and RPR registers depends on
the value of SCR_EL3.FIQ.

The values non secure EL1 sees from the distributor and redistributor
depend on whether security is enabled for the GIC or not.

To avoid having to deal with two sets of values for PMR
masking/unmasking, only enable pseudo-NMIs when GIC has non-secure view
of priorities.

Also, add firmware requirements related to SCR_EL3.
Signed-off-by: Julien Thierry <julien.thierry@arm.com>
Acked-by: Marc Zyngier <marc.zyngier@arm.com>
Cc: Will Deacon <will.deacon@arm.com>
Cc: Jonathan Corbet <corbet@lwn.net>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Jason Cooper <jason@lakedaemon.net>
Cc: Marc Zyngier <marc.zyngier@arm.com>
Signed-off-by: Catalin Marinas <catalin.marinas@arm.com>

Implement architecture specific primitive allowing the GICv3 driver to
use priorities to mask interrupts.
Signed-off-by: Julien Thierry <julien.thierry@arm.com>
Suggested-by: Daniel Thompson <daniel.thompson@linaro.org>
Acked-by: Marc Zyngier <marc.zyngier@arm.com>
Cc: Marc Zyngier <marc.zyngier@arm.com>
Cc: Will Deacon <will.deacon@arm.com>
Signed-off-by: Catalin Marinas <catalin.marinas@arm.com>

Once the boot CPU has been prepared or a new secondary CPU has been
brought up, use ICC_PMR_EL1 to mask interrupts on that CPU and clear
PSR.I bit.

Since ICC_PMR_EL1 is initialized at CPU bringup, avoid overwriting
it in the GICv3 driver.
Signed-off-by: Julien Thierry <julien.thierry@arm.com>
Suggested-by: Daniel Thompson <daniel.thompson@linaro.org>
Acked-by: Marc Zyngier <marc.zyngier@arm.com>
Cc: Will Deacon <will.deacon@arm.com>
Cc: James Morse <james.morse@arm.com>
Cc: Marc Zyngier <marc.zyngier@arm.com>
Signed-off-by: Catalin Marinas <catalin.marinas@arm.com>

The code to detect whether Linux has access to group0 interrupts can
prove useful in other parts of the driver.

Provide a separate function to do this.
Signed-off-by: Julien Thierry <julien.thierry@arm.com>
Acked-by: Marc Zyngier <marc.zyngier@arm.com>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Jason Cooper <jason@lakedaemon.net>
Cc: Marc Zyngier <marc.zyngier@arm.com>
Signed-off-by: Catalin Marinas <catalin.marinas@arm.com>

Currently alternatives are applied very late in the boot process (and
a long time after we enable scheduling). Some alternative sequences,
such as those that alter the way CPU context is stored, must be applied
much earlier in the boot sequence.

Introduce apply_boot_alternatives() to allow some alternatives to be
applied immediately after we detect the CPU features of the boot CPU.
Signed-off-by: Daniel Thompson <daniel.thompson@linaro.org>
[julien.thierry@arm.com: rename to fit new cpufeature framework better,
			 apply BOOT_SCOPE feature early in boot]
Signed-off-by: Julien Thierry <julien.thierry@arm.com>
Reviewed-by: Suzuki K Poulose <suzuki.poulose@arm.com>
Reviewed-by: Marc Zyngier <marc.zyngier@arm.com>
Cc: Will Deacon <will.deacon@arm.com>
Cc: Christoffer Dall <christoffer.dall@arm.com>
Cc: Suzuki K Poulose <suzuki.poulose@arm.com>
Signed-off-by: Catalin Marinas <catalin.marinas@arm.com>

In preparation for the application of alternatives at different points
during the boot process, provide the possibility to check whether
alternatives for a feature of interest was already applied instead of
having a global boolean for all alternatives.

Make VHE enablement code check for the VHE feature instead of considering
all alternatives.
Signed-off-by: Julien Thierry <julien.thierry@arm.com>
Acked-by: Marc Zyngier <marc.zyngier@arm.com>
Cc: Will Deacon <will.deacon@arm.com>
Cc: Suzuki K Poulose <suzuki.poulose@arm.com>
Cc: Marc Zyngier <Marc.Zyngier@arm.com>
Cc: Christoffer Dall <Christoffer.Dall@arm.com>
Signed-off-by: Catalin Marinas <catalin.marinas@arm.com>

The addition of PMR should not bypass the semantics of daifflags.

When DA_F are set, I bit is also set as no interrupts (even of higher
priority) is allowed.

When DA_F are cleared, I bit is cleared and interrupt enabling/disabling
goes through ICC_PMR_EL1.
Signed-off-by: Julien Thierry <julien.thierry@arm.com>
Reviewed-by: Catalin Marinas <catalin.marinas@arm.com>
Reviewed-by: Marc Zyngier <marc.zyngier@arm.com>
Cc: Will Deacon <will.deacon@arm.com>
Cc: James Morse <james.morse@arm.com>
Signed-off-by: Catalin Marinas <catalin.marinas@arm.com>

Instead disabling interrupts by setting the PSR.I bit, use a priority
higher than the one used for interrupts to mask them via PMR.

When using PMR to disable interrupts, the value of PMR will be used
instead of PSR.[DAIF] for the irqflags.
Signed-off-by: Julien Thierry <julien.thierry@arm.com>
Suggested-by: Daniel Thompson <daniel.thompson@linaro.org>
Acked-by: Ard Biesheuvel <ard.biesheuvel@linaro.org>
Reviewed-by: Catalin Marinas <catalin.marinas@arm.com>
Cc: Will Deacon <will.deacon@arm.com>
Cc: Ard Biesheuvel <ard.biesheuvel@linaro.org>
Cc: Oleg Nesterov <oleg@redhat.com>
Signed-off-by: Catalin Marinas <catalin.marinas@arm.com>

Currently, irqflags are saved before calling runtime services and
checked for mismatch on return.

Provide a pair of overridable macros to save and restore (if needed) the
state that need to be preserved on return from a runtime service.
This allows to check for flags that are not necesarly related to
irqflags.
Signed-off-by: Julien Thierry <julien.thierry@arm.com>
Acked-by: Catalin Marinas <catalin.marinas@arm.com>
Acked-by: Ard Biesheuvel <ard.biesheuvel@linaro.org>
Acked-by: Marc Zyngier <marc.zyngier@arm.com>
Cc: Ard Biesheuvel <ard.biesheuvel@linaro.org>
Cc: linux-efi@vger.kernel.org
Signed-off-by: Catalin Marinas <catalin.marinas@arm.com>

Interrupts masked by ICC_PMR_EL1 will not be signaled to the CPU. This
means that hypervisor will not receive masked interrupts while running a
guest.

We need to make sure that all maskable interrupts are masked from the
time we call local_irq_disable() in the main run loop, and remain so
until we call local_irq_enable() after returning from the guest, and we
need to ensure that we see no interrupts at all (including pseudo-NMIs)
in the middle of the VM world-switch, while at the same time we need to
ensure we exit the guest when there are interrupts for the host.

We can accomplish this with pseudo-NMIs enabled by:
  (1) local_irq_disable: set the priority mask
  (2) enter guest: set PSTATE.I
  (3)              clear the priority mask
  (4) eret to guest
  (5) exit guest:  set the priotiy mask
                   clear PSTATE.I (and restore other host PSTATE bits)
  (6) local_irq_enable: clear the priority mask.
Signed-off-by: Julien Thierry <julien.thierry@arm.com>
Acked-by: Catalin Marinas <catalin.marinas@arm.com>
Reviewed-by: Marc Zyngier <marc.zyngier@arm.com>
Reviewed-by: Christoffer Dall <christoffer.dall@arm.com>
Cc: Christoffer Dall <christoffer.dall@arm.com>
Cc: Marc Zyngier <marc.zyngier@arm.com>
Cc: Will Deacon <will.deacon@arm.com>
Cc: kvmarm@lists.cs.columbia.edu
Signed-off-by: Catalin Marinas <catalin.marinas@arm.com>

CPU does not received signals for interrupts with a priority masked by
ICC_PMR_EL1. This means the CPU might not come back from a WFI
instruction.

Make sure ICC_PMR_EL1 does not mask interrupts when doing a WFI.

Since the logic of cpu_do_idle is becoming a bit more complex than just
two instructions, lets turn it from ASM to C.
Signed-off-by: Julien Thierry <julien.thierry@arm.com>
Suggested-by: Daniel Thompson <daniel.thompson@linaro.org>
Reviewed-by: Catalin Marinas <catalin.marinas@arm.com>
Reviewed-by: Marc Zyngier <marc.zyngier@arm.com>
Cc: Will Deacon <will.deacon@arm.com>
Signed-off-by: Catalin Marinas <catalin.marinas@arm.com>

In order to replace PSR.I interrupt disabling/enabling with ICC_PMR_EL1
interrupt masking, ICC_PMR_EL1 needs to be saved/restored when
taking/returning from an exception. This mimics the way hardware saves
and restores PSR.I bit in spsr_el1 for exceptions and ERET.

Add PMR to the registers to save in the pt_regs struct upon kernel entry,
and restore it before ERET. Also, initialize it to a sane value when
creating new tasks.
Signed-off-by: Julien Thierry <julien.thierry@arm.com>
Reviewed-by: Catalin Marinas <catalin.marinas@arm.com>
Reviewed-by: Marc Zyngier <marc.zyngier@arm.com>
Cc: Will Deacon <will.deacon@arm.com>
Cc: Oleg Nesterov <oleg@redhat.com>
Cc: Dave Martin <Dave.Martin@arm.com>
Signed-off-by: Catalin Marinas <catalin.marinas@arm.com>

Introduce fixed values for PMR that are going to be used to mask and
unmask interrupts by priority.

The current priority given to GIC interrupts is 0xa0, so clearing PMR's
most significant bit is enough to mask interrupts.
Signed-off-by: Julien Thierry <julien.thierry@arm.com>
Suggested-by: Daniel Thompson <daniel.thompson@linaro.org>
Acked-by: Catalin Marinas <catalin.marinas@arm.com>
Acked-by: Marc Zyngier <marc.zyngier@arm.com>
Cc: Oleg Nesterov <oleg@redhat.com>
Cc: Will Deacon <will.deacon@arm.com>
Signed-off-by: Catalin Marinas <catalin.marinas@arm.com>

Mask the IRQ priority through PMR and re-enable IRQs at CPU level,
allowing only higher priority interrupts to be received during interrupt
handling.
Signed-off-by: Julien Thierry <julien.thierry@arm.com>
Acked-by: Catalin Marinas <catalin.marinas@arm.com>
Acked-by: Marc Zyngier <marc.zyngier@arm.com>
Cc: Will Deacon <will.deacon@arm.com>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Jason Cooper <jason@lakedaemon.net>
Cc: Marc Zyngier <marc.zyngier@arm.com>
Signed-off-by: Catalin Marinas <catalin.marinas@arm.com>

Add helper functions to access system registers related to interrupt
priorities: PMR and RPR.
Signed-off-by: Julien Thierry <julien.thierry@arm.com>
Reviewed-by: Mark Rutland <mark.rutland@arm.com>
Acked-by: Catalin Marinas <catalin.marinas@arm.com>
Reviewed-by: Marc Zyngier <marc.zyngier@arm.com>
Cc: Russell King <linux@armlinux.org.uk>
Cc: Will Deacon <will.deacon@arm.com>
Cc: Marc Zyngier <marc.zyngier@arm.com>
Signed-off-by: Catalin Marinas <catalin.marinas@arm.com>

Add a cpufeature indicating whether a cpu supports masking interrupts
by priority.

The feature will be properly enabled in a later patch.
Signed-off-by: Julien Thierry <julien.thierry@arm.com>
Reviewed-by: Suzuki K Poulose <suzuki.poulose@arm.com>
Reviewed-by: Mark Rutland <mark.rutland@arm.com>
Acked-by: Catalin Marinas <catalin.marinas@arm.com>
Acked-by: Marc Zyngier <marc.zyngier@arm.com>
Cc: Will Deacon <will.deacon@arm.com>
Cc: Marc Zyngier <marc.zyngier@arm.com>
Cc: Suzuki K Poulose <suzuki.poulose@arm.com>
Signed-off-by: Catalin Marinas <catalin.marinas@arm.com>

It is not supported to have some CPUs using GICv3 sysreg CPU interface
while some others do not.

Once ICC_SRE_EL1.SRE is set on a CPU, the bit cannot be cleared. Since
matching this feature require setting ICC_SRE_EL1.SRE, it cannot be
turned off if found on a CPU.

Set the feature as STRICT_BOOT, if boot CPU has it, all other CPUs are
required to have it.
Signed-off-by: Julien Thierry <julien.thierry@arm.com>
Suggested-by: Daniel Thompson <daniel.thompson@linaro.org>
Reviewed-by: Suzuki K Poulose <suzuki.poulose@arm.com>
Reviewed-by: Mark Rutland <mark.rutland@arm.com>
Acked-by: Catalin Marinas <catalin.marinas@arm.com>
Acked-by: Marc Zyngier <marc.zyngier@arm.com>
Cc: Will Deacon <will.deacon@arm.com>
Cc: Suzuki K Poulose <suzuki.poulose@arm.com>
Cc: Marc Zyngier <marc.zyngier@arm.com>
Signed-off-by: Catalin Marinas <catalin.marinas@arm.com>

There are some helpers to modify PSR.[DAIF] bits that are not referenced
anywhere. The less these bits are available outside of local_irq_*
functions the better.

Get rid of those unused helpers.
Signed-off-by: Julien Thierry <julien.thierry@arm.com>
Reviewed-by: Mark Rutland <mark.rutland@arm.com>
Acked-by: Catalin Marinas <catalin.marinas@arm.com>
Acked-by: Marc Zyngier <marc.zyngier@arm.com>
Cc: Will Deacon <will.deacon@arm.com>
Cc: James Morse <james.morse@arm.com>
Signed-off-by: Catalin Marinas <catalin.marinas@arm.com>

When using VHE, the host needs to clear HCR_EL2.TGE bit in order
to interact with guest TLBs, switching from EL2&0 translation regime
to EL1&0.

However, some non-maskable asynchronous event could happen while TGE is
cleared like SDEI. Because of this address translation operations
relying on EL2&0 translation regime could fail (tlb invalidation,
userspace access, ...).

Fix this by properly setting HCR_EL2.TGE when entering NMI context and
clear it if necessary when returning to the interrupted context.
Signed-off-by: Julien Thierry <julien.thierry@arm.com>
Suggested-by: Marc Zyngier <marc.zyngier@arm.com>
Reviewed-by: Marc Zyngier <marc.zyngier@arm.com>
Reviewed-by: James Morse <james.morse@arm.com>
Cc: Arnd Bergmann <arnd@arndb.de>
Cc: Will Deacon <will.deacon@arm.com>
Cc: Marc Zyngier <marc.zyngier@arm.com>
Cc: James Morse <james.morse@arm.com>
Cc: linux-arch@vger.kernel.org
Cc: stable@vger.kernel.org
Signed-off-by: Catalin Marinas <catalin.marinas@arm.com>

* 'irq/generic-nmi' of git://git.kernel.org/pub/scm/linux/kernel/git/maz/arm-platforms:
  irqdesc: Add domain handler for NMIs
  genirq: Provide NMI handlers
  genirq: Provide NMI management for percpu_devid interrupts
  genirq: Provide basic NMI management for interrupt lines

NMI handling code should be executed between calls to nmi_enter and
nmi_exit.

Add a separate domain handler to properly setup NMI context when handling
an interrupt requested as NMI.
Signed-off-by: Julien Thierry <julien.thierry@arm.com>
Acked-by: Marc Zyngier <marc.zyngier@arm.com>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Marc Zyngier <marc.zyngier@arm.com>
Cc: Will Deacon <will.deacon@arm.com>
Cc: Peter Zijlstra <peterz@infradead.org>
Signed-off-by: Marc Zyngier <marc.zyngier@arm.com>

Provide flow handlers that are NMI safe for interrupts and percpu_devid
interrupts.
Signed-off-by: Julien Thierry <julien.thierry@arm.com>
Acked-by: Marc Zyngier <marc.zyngier@arm.com>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Marc Zyngier <marc.zyngier@arm.com>
Cc: Peter Zijlstra <peterz@infradead.org>
Signed-off-by: Marc Zyngier <marc.zyngier@arm.com>

Add support for percpu_devid interrupts treated as NMIs.

Percpu_devid NMIs need to be setup/torn down on each CPU they target.

The same restrictions as for global NMIs still apply for percpu_devid NMIs.
Signed-off-by: Julien Thierry <julien.thierry@arm.com>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Ingo Molnar <mingo@kernel.org>
Cc: Marc Zyngier <marc.zyngier@arm.com>
Signed-off-by: Marc Zyngier <marc.zyngier@arm.com>

Add functionality to allocate interrupt lines that will deliver IRQs
as Non-Maskable Interrupts. These allocations are only successful if
the irqchip provides the necessary support and allows NMI delivery for the
interrupt line.

Interrupt lines allocated for NMI delivery must be enabled/disabled through
enable_nmi/disable_nmi_nosync to keep their state consistent.

To treat a PERCPU IRQ as NMI, the interrupt must not be shared nor threaded,
the irqchip directly managing the IRQ must be the root irqchip and the
irqchip cannot be behind a slow bus.
Signed-off-by: Julien Thierry <julien.thierry@arm.com>
Reviewed-by: Marc Zyngier <marc.zyngier@arm.com>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Ingo Molnar <mingo@kernel.org>
Cc: Marc Zyngier <marc.zyngier@arm.com>
Signed-off-by: Marc Zyngier <marc.zyngier@arm.com>

Since the enabling and disabling of IRQs within preempt_schedule_irq()
is contained in a need_resched() loop, we don't need the outer arch
code loop.
Reported-by: Julien Thierry <julien.thierry@arm.com>
Reported-by: Will Deacon <will.deacon@arm.com>
Reviewed-by: Julien Thierry <julien.thierry@arm.com>
Acked-by: Will Deacon <will.deacon@arm.com>
Signed-off-by: Valentin Schneider <valentin.schneider@arm.com>
Cc: Mark Rutland <mark.rutland@arm.com>
Cc: Marc Zyngier <marc.zyngier@arm.com>
Cc: Julien Grall <julien.grall@arm.com>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: linux-arm-kernel@lists.infradead.org
Signed-off-by: Catalin Marinas <catalin.marinas@arm.com>

As of commit e2a2e56e ("arm64: dump: no need to check return value
of debugfs_create functions") in the arm64 for-next/core branch,
ptdump_debugfs_register does not have a return value, which causes a
build error here:

drivers/firmware/efi/arm-runtime.c:51:9: error: returning 'void' from a
function with incompatible result type 'int'
        return ptdump_debugfs_register(&efi_ptdump_info, "efi_page_tables");
               ^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
1 error generated.

The arm version is still awaiting acceptance [1] but in anticipation
of that patch being merged, restructure this function to call
ptdump_debugfs_register without expecting a return value.

[1]: https://lore.kernel.org/lkml/20190122144114.9816-3-gregkh@linuxfoundation.org/Acked-by: Ard Biesheuvel <ard.biesheuvel@linaro.org>
Signed-off-by: Nathan Chancellor <natechancellor@gmail.com>
Signed-off-by: Catalin Marinas <catalin.marinas@arm.com>