Commit graph

2344 commits

Author SHA1 Message Date
Luuk Bosma
dfb80526b4 arch: arm: aarch32: clear CONTROL.FPCA for every CPU that has a FPU
Upon reset, the CONTROL.FPCA bit is, normally, cleared. However,
it might be left un-cleared by firmware running before Zephyr boot,
for example when Zephyr image is loaded by another image.
We must clear this bit to prevent errors in exception unstacking.
This caused stack offset when booting from a build-in EFM32GG bootloader

Fixes #22977

Signed-off-by: Luuk Bosma <l.bosma@interay.com>
2020-02-27 19:26:04 +02:00
Luuk Bosma
cc21aba55f arch: arm: aarch32: clear CPACR for every CPU that has a FPU
Upon reset, the Co-Processor Access Control Register is, normally,
0x00000000. However, it might be left un-cleared by firmware running
before Zephyr boot.
This restores the register back to reset value, even if CONFIG_FLOAT
is not set.
Clearing before setting supports switching between Full access
and Privileged access only.

Refactor enable_floating_point to support initialize
floating point registers for every CPU that has a FPU.

Signed-off-by: Luuk Bosma <l.bosma@interay.com>
2020-02-27 19:26:04 +02:00
Abhishek Shah
f587c5f019 arch: arm64: mmu: Add zephyr execution regions
Add zephyr execution regions(text, rodata, data, noinit, bss, etc.)
with proper attributes to translation tables.
Linker script has been modified a little to align these sections to
minimum translation granule(4 kB).

With this in place, code cannot be overwritten accidently as it is
marked read only. Similarly, execution is prohibited from data/RW
section as it is marked execute-never.

Signed-off-by: Abhishek Shah <abhishek.shah@broadcom.com>
2020-02-20 17:24:59 +02:00
Abhishek Shah
10a05a162f arch: arm64: Add MMU support
Add MMU support for ARMv8A. We support 4kB translation granule.
Regions to be mapped with specific attributes are required to be
at least 4kB aligned and can be provided through platform file(soc.c).

Signed-off-by: Abhishek Shah <abhishek.shah@broadcom.com>
2020-02-20 17:24:59 +02:00
Ioannis Glaropoulos
f8a5f0330d arch: arm: mpu: protect RNR when reading RBAR, RASR in ARMv7-M driver
We lock IRQs around writing to RNR and immediate reading of RBAR
RASR in ARMv7-M MPU driver. We do this for the functions invoked
directly or undirectly by arch_buffer_validate(). This locking
guarantees that
- arch_buffer_validate() calls by ISRs may safely preempt each
  other
- arch_buffer_validate() calls by threads may safely preempt
  each other (i.e via context switch -out and -in again).

Signed-off-by: Ioannis Glaropoulos <Ioannis.Glaropoulos@nordicsemi.no>
2020-02-19 12:19:43 -08:00
Ioannis Glaropoulos
db0ca2e31a arch: arm: userspace: lock swap to set PSP, PSPLIM in userspace enter
When entering user mode, and before the privileged are dropped,
the thread switches back to using its default (user) stack. For
stack limit checking not to lead to a stack overflow, the PSPLIM
and PSP register updates need to be done with PendSV IRQ locked.
This is because context-switch (done in PendSV IRQ) reprograms
the stack pointer limit register based on the current PSP
of the thread. This commit enforces PendSV locking and
unlocking while reprogramming PSP and PSPLIM when switching to
user stack at z_arm_userspace_enter().

Signed-off-by: Ioannis Glaropoulos <Ioannis.Glaropoulos@nordicsemi.no>
2020-02-19 12:19:43 -08:00
Ioannis Glaropoulos
b09607dee5 arch: arm: aarch32: no PSLIM clearing in z_arm_userspace_enter()
Modifying the PSP via an MSR instruction is not subject to
stack limit checking so we can remove the relevant code
block in the begining of z_arm_userspace_enter(), which clears
PSPLIM. We add a comment when setting the PSP to the privilege
stack to stress that clearing the PSPLIM is not required and it
is always a safe operation.

Signed-off-by: Ioannis Glaropoulos <Ioannis.Glaropoulos@nordicsemi.no>
2020-02-19 12:19:43 -08:00
Ioannis Glaropoulos
c4c595c56e arch: arm: userspace: lock swap to set PSP & PSPLIM in syscall return
When returning from a system call, the thread switches back
to using its default (user) stack. For stack limit checking
not to lead to a stack overflow, the updates of PSPLIM and
PSP registers need to be done with PendSV IRQ locked. This
is because context-switch (done in PendSV IRQ) reprograms
the stack pointer limit register based on the current PSP
of the thread. This commit enforces PendSV locking and
unlocking while reprogramming PSP and PSPLIM when returning
from a system call.

Signed-off-by: Ioannis Glaropoulos <Ioannis.Glaropoulos@nordicsemi.no>
2020-02-19 12:19:43 -08:00
Ioannis Glaropoulos
6494658983 arch: arm: userspace: no PSPLIM clearing in z_arm_do_syscall() enter
In this commit we remove the PSPLIM clearing when entering
z_arm_do_syscall(), since we want PSPLIM to keep guarding
the user thread stack, until the thread has switched to its
privileged stack, for executing the system call.

Signed-off-by: Ioannis Glaropoulos <Ioannis.Glaropoulos@nordicsemi.no>
2020-02-19 12:19:43 -08:00
Ioannis Glaropoulos
f00dfce891 arch: arm: userspace: set PSPLIM to guard default stack in SVCall
Thread will be in privileged mode after returning from SCVall. It
will use the default (user) stack before switching to the privileged
stack to execute the system call. We need to protect the user stack
against stack overflows until this stack transition. We update the
note in z_arm_do_syscall(), stating clearly that it executing with
stack protection when building with stack limit checking support
(ARMv8-M only).

Signed-off-by: Ioannis Glaropoulos <Ioannis.Glaropoulos@nordicsemi.no>
2020-02-19 12:19:43 -08:00
Ioannis Glaropoulos
a5ecd71163 arch: arm: cortex-m: fix PSPLIM configuring in context-switch
When configuring the built-in stack guard, via setting the
PSPLIM register, during thread context-switch, we shall only
set PSPLIM to "guard" the thread's privileged stack area when
the thread is actually using it (PSP is on this stack).

Signed-off-by: Ioannis Glaropoulos <Ioannis.Glaropoulos@nordicsemi.no>
2020-02-19 12:19:43 -08:00
Ioannis Glaropoulos
16ce4b6953 arch: arm: cortex-m: move PSPLIM clearing in the relevant function
We do not need to have the PSPLIM clearing directly inside
the PendSV handler and outside the function that configures
it, configure_builtin_stack_guard(), since the latter is also
invoked inside the PendSV handler. This commit moves the
PSPLIM clearing inside configure_builtin_stack_guard(). The
patch is not introducing any behavioral change on the
stack limit checking mechanism for Cortex-M.

Signed-off-by: Ioannis Glaropoulos <Ioannis.Glaropoulos@nordicsemi.no>
2020-02-19 12:19:43 -08:00
Ioannis Glaropoulos
36e80673f9 arch: arm: aarch32: cortex-m: introduce offset for stack info start
We add the mechanism to generate offset #defines for
thread stack info start, to be used directly in ASM.

Signed-off-by: Ioannis Glaropoulos <Ioannis.Glaropoulos@nordicsemi.no>
2020-02-19 12:19:43 -08:00
Ioannis Glaropoulos
4223b71b77 arch: aarch32: define macro for PendSV IRQ priority level
We introduce a macro to define the IRQ priority level for
PendsV, and use it in arch/arm/include/aarch32/exc.h
to set the PendSV IRQ level. The commit does not change
the behavior of PendSV interrupt.

Signed-off-by: Ioannis Glaropoulos <Ioannis.Glaropoulos@nordicsemi.no>
2020-02-19 12:19:43 -08:00
Ioannis Glaropoulos
f9d9b7642e arch: aarch32: document exception priority scheme for 32-bit ARM
This commit adds some documentation for the exception
priority scheme for 32-bit ARM architecture variants.
In addition we document that SVCall priority level for
ARMv6-M is implicitly set to highest (by leaving it as
default).

Signed-off-by: Ioannis Glaropoulos <Ioannis.Glaropoulos@nordicsemi.no>
2020-02-19 12:19:43 -08:00
Ioannis Glaropoulos
446ac06458 arch: arm: core: aarch32: fix wrong indentation in thread.c
Some minor indentation fixes in thread.c.

Signed-off-by: Ioannis Glaropoulos <Ioannis.Glaropoulos@nordicsemi.no>
2020-02-19 12:19:43 -08:00
Ulf Magnusson
378d6b137a kconfig: Replace non-defconfig single-symbol 'if's with 'depends on'
Same deal as in commit eddd98f811 ("kconfig: Replace some single-symbol
'if's with 'depends on'"), for the remaining cases outside defconfig
files. See that commit for an explanation.

Will do the defconfigs separately in case there are any complaints
there.

Signed-off-by: Ulf Magnusson <Ulf.Magnusson@nordicsemi.no>
2020-02-12 10:32:34 -06:00
Stephanos Ioannidis
bea3ee0ed0 arch: arm: Fix incorrect Cortex-R interrupt state control logic.
This commit fixes incorrect Cortex-R interrupt lock, unlock and state
check function implementations.

The issues can be summarised as follows:

1. The current implementation of 'z_arch_irq_lock' returns the value
  of CPSR as the IRQ key and, since CPSR contains many other state
  bits, this caused 'z_arch_irq_unlocked' to return false even when
  IRQ is unlocked. This problem is fixed by isolating only the I-bit
  of CPSR and returning this value as the IRQ key, such that it
  returns a non-zero value when interrupt is disabled.

2. The current implementation of 'z_arch_irq_unlock' directly updates
  the value of CPSR control field with the IRQ key and this can cause
  other state bits in CPSR to be corrupted. This problem is fixed by
  conditionally enabling interrupt using CPSIE instruction when the
  value of IRQ key is a zero.

3. The current implementation of 'z_arch_is_in_isr' checks the value
  of CPSR MODE field and returns true if its value is IRQ or FIQ.
  While this does not normally cause an issue, the function can return
  false when IRQ offloading is used because the offload function
  executes in SVC mode. This problem is fixed by adding check for SVC
  mode.

Signed-off-by: Stephanos Ioannidis <root@stephanos.io>
2020-02-11 08:03:37 -08:00
Ulf Magnusson
7b52475720 kconfig: Remove duplicated ARM_MPU dependency on CUSTOM_SECTION_ALIGN
CUSTOM_SECTION_ALIGN is already defined within an 'if ARM_MPU', so it
does not need a 'depends on ARM_MPU'.

Flagged by https://github.com/zephyrproject-rtos/ci-tools/pull/128.

Signed-off-by: Ulf Magnusson <Ulf.Magnusson@nordicsemi.no>
2020-02-07 15:50:33 -06:00
Ulf Magnusson
1b604b946c kconfig: arm: Remove 'if CPU_CORTEX_R' within 'if CPU_CORTEX_R'
Flagged by https://github.com/zephyrproject-rtos/ci-tools/pull/128.

Signed-off-by: Ulf Magnusson <Ulf.Magnusson@nordicsemi.no>
2020-02-07 15:48:29 -06:00
Anas Nashif
73008b427c tracing: move headers under include/tracing
Move tracing.h to include/tracing/ to align with subsystem reorg.

Signed-off-by: Anas Nashif <anas.nashif@intel.com>
2020-02-07 15:58:05 -05:00
Wentong Wu
aa5d45d7cc tracing: add TRACING_ISR Kconfig
Add TRACING_ISR Kconfig to help high latency backend working well.

Currently the ISR tracing hook function is put at the begining and
ending of ISR wrapper, when there is ISR needed in the tracing path
(especially tracing backend), it will cause tracing buffer easily
be exhausted if async tracing method enabled. Also it will increase
system latency if all the ISRs are traced. So add TRACING_ISR to
enable/disable ISR tracing here. Later a filter out mechanism based
on irq number will be added.

Signed-off-by: Wentong Wu <wentong.wu@intel.com>
2020-02-05 23:54:26 -05:00
Carlo Caione
0958673ee1 arch: arm64: Enable shared IRQ line for UART
Enable the shared IRQ for the UART line and enable the remaining tasks
that depends on a separated declaration of the TX/RX/Err/... IRQs.

Signed-off-by: Carlo Caione <ccaione@baylibre.com>
2020-02-01 08:08:43 -05:00
Carlo Caione
3cdead707d arch: arm64: Fix cmsis_rtos tests
The cmsis_rtos tests are failing because the stack size used by CMSIS is
too small. Customize the stack size for the aarch64 architecture and
re-enable the tests.

Signed-off-by: Carlo Caione <ccaione@baylibre.com>
2020-02-01 08:08:43 -05:00
Carlo Caione
3aef85458d arch: arm64: Dump registers content on fatal error
Extend the ESF structure and dump the most important registers in the
error exception handler.

Signed-off-by: Carlo Caione <ccaione@baylibre.com>
2020-02-01 08:08:43 -05:00
Carlo Caione
6531d1c649 arch: arm64: Enable config option to switch from EL3 to EL1
ARMv8-A SoCs enter EL3 after reset. Add a new config option
(CONFIG_SWITCH_TO_EL1) to switch from EL3 to EL1 at boot and default it
to 'y'.

Signed-off-by: Carlo Caione <ccaione@baylibre.com>
2020-02-01 08:08:43 -05:00
Carlo Caione
0d5e011be4 arch: arm64: Enable tracing
Enable the tracing hooks on the ARM64 platform and white-list the
tracing tests.

Signed-off-by: Carlo Caione <ccaione@baylibre.com>
2020-02-01 08:08:43 -05:00
Carlo Caione
528319bff7 arch: arm64: Support all the ELn
While QEMU's Cortex-A53 emulation by default only emulates a CPU in EL1,
other QEMU forks (for example the QEMU released by Xilinx) and real
hardware starts in EL3.

To support all the ELn we introduce a macro to identify at run-time the
Exception Level and take the correct actions.

Signed-off-by: Carlo Caione <ccaione@baylibre.com>
2020-02-01 08:08:43 -05:00
Carlo Caione
87d8a035dd arch: arm64: Support aarch64-gcc compiler
To be able to successfully compile the kernel for the ARM64 architecture
we have to tweak the compiler-related files to be able to use the
AArch64 GCC compiler.

Signed-off-by: Carlo Caione <ccaione@baylibre.com>
2020-02-01 08:08:43 -05:00
Carlo Caione
1be0c05311 arch: arm64: Introduce ARM64 (AArch64) architecture
Introduce the basic ARM64 architecture support.

A new CONFIG_ARM64 symbol is introduced for the new architecture and new
cmake / Kconfig files are added to switch between ARM and ARM64.

Signed-off-by: Carlo Caione <ccaione@baylibre.com>
2020-02-01 08:08:43 -05:00
Ioannis Glaropoulos
8345434a24 arch: arm: mpu: no dynamic MPU re-program in swap if not required
Dynamic MPU regions are used in build configurations with User
mode or MPU-based stack-overflow guards. If these features are
disabled, we skip calling the ARM function for re-programming
the MPU peripheral during context-switch. We also skip doing
this when jumping to main thread (although this brings limited
performace gain as it is called once in the boot cycle)

Signed-off-by: Ioannis Glaropoulos <Ioannis.Glaropoulos@nordicsemi.no>
2020-01-31 21:38:35 +01:00
Øyvind Rønningstad
05f0d85b6a extensions.cmake: Replace TEXT_START with ROM_START
In zephyr_linker_sources().
This is done since the point of the location is to place things at given
offsets. This can only be done consistenly if the linker code is placed
into the _first_ section.

All uses of TEXT_START are replaced with ROM_START.

ROM_START is only supported in some arches, as some arches have several
custom sections before text. These don't currently have ROM_START or
TEXT_START available, but that could be added with a bit of refactoring
in their linker script.

No SORT_KEYs are changed.

This also fixes an error introduced when TEXT_START was added, where
TEXT_SECTION_OFFSET was applied to riscv's common linker.ld instead of
to openisa_rv32m1's specific linker.ld.

Signed-off-by: Øyvind Rønningstad <oyvind.ronningstad@nordicsemi.no>
2020-01-23 03:22:59 -08:00
Ioannis Glaropoulos
5fcbe4e5d5 arch: arm: cortex-m: move openocd sections after _vector_end
openocd linker sections are not supposed to be part of the
vector table sections. Place the sections after we define
the _vector_end linker symbol.

Signed-off-by: Ioannis Glaropoulos <Ioannis.Glaropoulos@nordicsemi.no>
2020-01-23 03:22:59 -08:00
Stephanos Ioannidis
c4e6bd2d7c arch: arm: cortex_m: Add CPU DWT feature symbol
This commit adds a Kconfig symbol for specifying whether the SoC
implements the CPU DWT feature.

The Data Watchpoint and Trace (DWT) is an optional debug unit for the
Cortex-M family cores (except ARMv6-M; i.e. M0 and M0+) that provides
watchpoints, data tracing and system profiling capabilities.

Signed-off-by: Stephanos Ioannidis <root@stephanos.io>
2020-01-20 14:05:47 +01:00
Stephanos Ioannidis
bc8524eb82 arch: arm: Rewrite Cortex-R reset vector function.
This commit addresses the following issues:

1. Add a new Kconfig configuration for specifying Dual-redundant Core
   Lock-step (DCLS) processor topology.

2. Register initialisation is only required when Dual-redundant Core
   Lock-step (DCLS) is implemented in hardware. This initialisation is
   required on DCLS only because the architectural registers are in an
   indeterminate state after reset and therefore the initial register
   state of the two parallel executing cores are not guaranteed to be
   identical, which can lead to DCCM detecting it as a hardware fault.
   A conditional compilation check for this hardware configuration
   using the newly added CONFIG_CPU_HAS_DCLS flag has been added.

3. The existing CPU register initialisation code did not take into
   account the banked registers for every execution mode. The new
   implementation ensures that all architectural registers of every
   mode are initialised.

4. Add VFP register initialisation for when floating-point support is
   enabled and the core is configured in DCLS topology. This
   initialisation sequence is required for the same reason given in
   the first issue.

5. Add provision for platform-specific initialisation on Cortex-R
   using PLATFORM_SPECIFIC_INIT config and z_platform_init function.

6. Remove seemingly pointless and inadequately defined STACK_MARGIN.
   Not only does it violate the 8-byte stack alignment rule, it does
   not provide any form of real stack protection.

Signed-off-by: Stephanos Ioannidis <root@stephanos.io>
2020-01-10 10:34:17 +01:00
Ioannis Glaropoulos
a07cb30d18 arch: arm: cortex-m: implement support for dynamic direct interrupts
This commits implements the support for dynamic direct
interrupts for the ARM Cortex-M architecture, and exposes
the support to the user as an ARM-only API.

Signed-off-by: Ioannis Glaropoulos <Ioannis.Glaropoulos@nordicsemi.no>
2020-01-08 10:15:09 -08:00
Ioannis Glaropoulos
33048680b0 arch: arm: introduce support for dynamic direct interrupts
With this commit we add support for Dynamic Direct interrupts
for the ARM Cortex-M architecture. For that we introduce a new,
user-enabled, Kconfig symbol, DYNAMIC_DIRECT_INTERRUPTS.

Signed-off-by: Ioannis Glaropoulos <Ioannis.Glaropoulos@nordicsemi.no>
2020-01-08 10:15:09 -08:00
Stephanos Ioannidis
916a8eb3a5 arch: arm: Fix Cortex-R power management interrupt handling
The system power management handling code in the '_isr_wrapper' enables
interrupts by executing the 'cpsie i' instruction, which causes a
system crash on the Cortex-R devices because the Cortex-R arch port
does not support nested interrupts at this time.

This commit restricts the interrupt state manipulations in the system
power management code to the Cortex-M arch, in order to prevent
interrupt nesting on other AArch32 family archs (only Cortex-R for
now).

Signed-off-by: Stephanos Ioannidis <root@stephanos.io>
2020-01-08 15:20:40 +01:00
Stephanos Ioannidis
cad30e817f arch: arm: Enable CMSIS-Core for Cortex-R by default
This commit enables the CMSIS-Core(R) processor interface driver for
the Cortex-R platforms by default.

The CMSIS-Core component provides a set of standard interface functions
to control the Cortex-R series processor cores and will be required by
the arch port as well as other CMSIS library components (e.g. CMSIS-DSP
and CMSIS-NN).

Signed-off-by: Stephanos Ioannidis <root@stephanos.io>
2020-01-02 16:59:04 -05:00
Ulf Magnusson
6ef29c0250 kconfig: Remove some redundant single-item menus and ifs
A single menu within an if like

    if FOO

    menu "blah"

    ...

    endmenu

    endif

can be replaced with

    menu "blah"
            depends on FOO

    ...

    endmenu

Fix up all existing instances.

Also remove redundant extra menus underneath 'menuconfig' symbols.
'menuconfig' already creates a menu.

Also remove the menu in arch/arm/core/aarch32/Kconfig around the
"Floating point ABI" choice. The choice depends on FLOAT, which depends
on CPU_HAS_CPU, so remove the 'depends on CPU_HAS_FPU' too.

Piggyback removing a redundant 'default n' for BME280.

Signed-off-by: Ulf Magnusson <Ulf.Magnusson@nordicsemi.no>
2019-12-21 10:26:54 -05:00
Carlo Caione
d048faacf2 aarch32: Add header shims to support old file locations
Out-of-tree code can still be using the old file locations. Introduce
header shims to include the headers from the new correct location and
print a warning message.

Add also a new Kconfig symbol to suppress such warning.

The shim will go away after two releases, so make sure to adapt your
application for the new locations.

Signed-off-by: Carlo Caione <ccaione@baylibre.com>
2019-12-20 11:40:59 -05:00
Carlo Caione
13e671e381 arch: arm: Fix header guards
Fix the header guards for the ARM header files to reflect the new code
location.

Signed-off-by: Carlo Caione <ccaione@baylibre.com>
2019-12-20 11:40:59 -05:00
Carlo Caione
aec9a8c4be arch: arm: Move ARM code to AArch32 sub-directory
Before introducing the code for ARM64 (AArch64) we need to relocate the
current ARM code to a new AArch32 sub-directory. For now we can assume
that no code is shared between ARM and ARM64.

There are no functional changes. The code is moved to the new location
and the file paths are fixed to reflect this change.

Signed-off-by: Carlo Caione <ccaione@baylibre.com>
2019-12-20 11:40:59 -05:00
Øyvind Rønningstad
1134f1b49d cortex_m: linker.ld: Port secure entry funcs to zephyr_linker_sources()
Place in its own linker snippet file.

Signed-off-by: Øyvind Rønningstad <oyvind.ronningstad@nordicsemi.no>
2019-12-20 08:54:53 -05:00
Øyvind Rønningstad
321462b310 arm: linker.ld: Port the vector table to zephyr_linker_sources()
Also port vector table relay.

Signed-off-by: Øyvind Rønningstad <oyvind.ronningstad@nordicsemi.no>
2019-12-20 08:54:53 -05:00
Kumar Gala
24ae1b1aa7 include: Fix use of <misc/FOO.h> -> <sys/FOO.h>
Fix #include <misc/FOO.h> as misc/FOO.h has been deprecated and
should be #include <sys/FOO.h>.

Signed-off-by: Kumar Gala <kumar.gala@linaro.org>
2019-12-10 08:39:37 -05:00
David B. Kinder
416a174ac2 doc: fix misspellings in docs
Fix misspellings in docs (and Kconfig and headers processed into docs)
missed during regular reviews.

Signed-off-by: David B. Kinder <david.b.kinder@intel.com>
2019-12-04 14:12:53 -06:00
Andrew Fernandes
d52ba5102a arch/arm: Fix formatting in arch/arm/core/fatal esf_dump
arch/arm/core/fatal: fix formatting in esf_dump

Signed-off-by: Andrew Fernandes <andrew@fernandes.org>
2019-11-18 13:51:47 +01:00
Stephanos Ioannidis
92625d710d arch: arm: Make PLATFORM_SPECIFIC_INIT available to all ARM variants.
Move PLATFORM_SPECIFIC_INIT declaration from Cortex-M Kconfig to the
ARM arch Kconfig in order to make it available for all ARM variants.

The rationale is that there is really no good reason why
platform-specific initialisation should be a Cortex-M-specific feature
and that Cortex-R port is expected to utilise this in a near future.

Signed-off-by: Stephanos Ioannidis <root@stephanos.io>
2019-11-08 19:17:58 +01:00
Stephanos Ioannidis
5ba0c8e0c5 arch: arm: Inline arch_isr_direct_header.
This commit inlines arch_isr_direct_header function that was previously
placed in irq_manage.c for no good reason (possibly in relation to the
FIXME for #3056).

In addition, since the PR #20119 resolved the header circular
dependency issue described in the issue #3056, this commit removes the
references to it in the code.

The reason for not inlining _arch_is_direct_pm as the #3056 FIXME
suggests is that there is little to gain from doing so and there still
exists circular dependency for the headers required by this function
(#20119 only addresses kernel_structs.h, which is required for _current
and _kernel, which, in turn, is required for handling interrupt nesting
in many architectures; in fact, Cortex-A and Cortex-R port will require
it as well).

Signed-off-by: Stephanos Ioannidis <root@stephanos.io>
2019-11-08 12:23:05 +01:00