In this commit we implement the assembly functions in
swap_helper.S, namely
- z_arm_pendsv()
- z_arm_svc()
for ARMv6-M and ARMv8-M Baseline architecture. We "inline" the
implementation for Baseline, along with the Mainline (ARMv7-M)
implementation, i.e. we rework only what is required to build
for Baseline Cortex-M.
Signed-off-by: Ioannis Glaropoulos <Ioannis.Glaropoulos@nordicsemi.no>
We do not support HW Stack protection capabilities in
Cortex-M Baseline CPUs (unless they have built-in stack
overflow detection capability). We adapt the Kconfig
option to reflect this.
Signed-off-by: Ioannis Glaropoulos <Ioannis.Glaropoulos@nordicsemi.no>
Remove the
# Omit prompt to signify a "hidden" option
comments that appear on some symbols. They seem to have been copy-pasted
at random, as there are lots of promptless symbols that don't have them
(that's confusing in itself, because it might give the idea that the
ones with comments are special in some way).
I suspect those comments wouldn't have helped me much if I didn't know
Kconfig either. There's a lot more Kconfig documentation now too, e.g.
https://docs.zephyrproject.org/latest/guides/kconfig/index.html.
Keep some comments that give more information than the symbol having no
prompt.
Also do some minor drive-by cleanup.
Signed-off-by: Ulf Magnusson <Ulf.Magnusson@nordicsemi.no>
This is an optional feature and no logic for it should
be present unless CONFIG_IRQ_OFFLOAD is enabled.
Signed-off-by: Andrew Boie <andrew.p.boie@intel.com>
Line up everything nicely, add leading '0x' to hex
addresses, and remove redundant newlines. Add
whitespace between the register name and contents
so the contents can be easily selected from a terminal.
Signed-off-by: Andrew Boie <andrew.p.boie@intel.com>
The struct definitions for pdpt, pd, and pt entries has been
removed:
- Bitfield ordering in a struct is implementation dependent,
it can be right-to-left or left-to-right
- The two different structures for page directory entries were
not being used consistently, or when the type of the PDE
was unknown
- Anonymous structs/unions are GCC extensions
Instead these are now u64_t, with bitwise operations used to
get/set fields.
A new set of inline functions for fetcing various page table
structures has been implemented, replacing the older macros.
Signed-off-by: Andrew Boie <andrew.p.boie@intel.com>
This hasn't been necessary since we dropped support for 32-bit
non-PAE page tables. Replace it with u64_t and scrub any
unnecessary casts left behind.
Signed-off-by: Andrew Boie <andrew.p.boie@intel.com>
This will be used for both 32-bit and 64-bit mode.
This header gets pulled in by x86's arch/cpu.h, so put
it in include/arch/x86/.
Signed-off-by: Andrew Boie <andrew.p.boie@intel.com>
Some assembly simplifications, to make code common for ARMv6
and ARMv7 architecture.
We can use ldrb, directly for reading the SVC encoding; this
removes the need for ANDing the result with 0xff right below.
We remove an immediate value of 0 from an str instruction, as
it's redundant.
Signed-off-by: Ioannis Glaropoulos <Ioannis.Glaropoulos@nordicsemi.no>
Add more documentation and inline explanatory comments in
assembly sources swap_helper.S and userspace.S and remove
redundant/wrong documentation when applicable.
Signed-off-by: Ioannis Glaropoulos <Ioannis.Glaropoulos@nordicsemi.no>
ARM user space requires ARM_MPU. We can, therefore,
remove the unnecessary #ifdef CONFIG_ARM_MPU blocks
in userspace.S. In addition, we do minor refactoring
in z_arm_userspace_enter(), and z_arm_pendsv(), and
z_arm_svc(), aiming at reducing the push/pop overhead
as much as possible.
Signed-off-by: Ioannis Glaropoulos <Ioannis.Glaropoulos@nordicsemi.no>
include/sys/arch_inlines.h will contain all architecture APIs
that are used by public inline functions and macros,
with implementations deriving from include/arch/cpu.h.
kernel/include/arch_interface.h will contain everything
else, with implementations deriving from
arch/*/include/kernel_arch_func.h.
Instances of duplicate documentation for these APIs have been
removed; implementation details have been left in place.
Signed-off-by: Andrew Boie <andrew.p.boie@intel.com>
Set the NXE bit in the EFER MSR so that the NX bit can
be set in page tables. Otherwise, the NX bit is treated
as reserved and leads to a fault if set.
Signed-off-by: Andrew Boie <andrew.p.boie@intel.com>
arch/arm/core is shared between Cortex-M and Cortex-R, so
enhance the file description headers accordingly.
Signed-off-by: Ioannis Glaropoulos <Ioannis.Glaropoulos@nordicsemi.no>
A clean-up commit that removes unnecessary inclusions from
assembly files in arm/core and arm/core/cortex_m. It also
ogranizes the inclusions based on the following order and
set of rules:
- never include kernel_structs.h
- include toolchain.h and linker/sections.h in all ASM files
- include offsets-short.h, if ASM accesses offset constants
- include arch/cpu.h, if ASM accesses CMSIS constants
(defined locally in include/arch/arm)
- include file-specific headers, if needed (e.g. vector-table.h)
Signed-off-by: Ioannis Glaropoulos <Ioannis.Glaropoulos@nordicsemi.no>
after recent changes in zephyr's fault handling, e.g. use log
to repace printk, it requires more stack to exception handling, or
the stack overflow may happen and crash the system.
this commit adds a kconfig option for exception stack size with
a larger default size.
Signed-off-by: Wayne Ren <wei.ren@synopsys.com>
The POSIX ARCH delegates some of the tasks which normally
are taken care of by the ARCH to the SOC or BOARD levels.
To avoid changes in the kernel-arch IF propagating into
the arch-soc and arch-board interfaces (which would break
off-tree posix boards) isolate them.
Also move arch inlined functions into the arch.h header,
and out from the headers which specify the posix arch-soc
and arch-board interfaces.
Signed-off-by: Alberto Escolar Piedras <alpi@oticon.com>
arch/cpu.h and kernel_arch_func.h are expected to define different
functions, per the architecture interface.
Signed-off-by: Andrew Boie <andrew.p.boie@intel.com>
There's no compelling reason why this should be inline unlike all
other arches, it's a large function, called exactly once.
Signed-off-by: Andrew Boie <andrew.p.boie@intel.com>
The specification for these arch APIs is to have them inline,
and the bodies were just oneliners calling another function
anyway.
Signed-off-by: Andrew Boie <andrew.p.boie@intel.com>
Add in-line documentation describing the process of register
preservation and exception handling on Cortex-R.
Signed-off-by: Stephanos Ioannidis <root@stephanos.io>
The interrupt exit and swap service routines for Cortex-R
unnecessarily preserve r0 and lr registers when making function calls
using bl instruction.
In case of _IntExit in exc_exit.S, the r0 register containing the
caller mode is preserved at the top, and the lr register can safely be
assumed to have been saved into the system mode stack by the interrupt
service routine.
In case of __svc in swap_helper.S, since the function saves lr to the
system mode stack at the top and exits through _IntExit, it is not
necessary to preserve lr register when executing bl instructions.
Signed-off-by: Stephanos Ioannidis <root@stephanos.io>
It's possible to have multiple processors configured without using the
SMP scheduler, so don't make definitions dependent on CONFIG_SMP.
Signed-off-by: Charles E. Youse <charles.youse@intel.com>
In non-SMP MP situations, the interrupt stacks might not exist, so
do not assume they do. Instead, initialize the TSS IST1 from the
cpuboot[] vector (meaning, on APs, the stack from z_arch_start_cpu).
Eliminates redundancy at the same time.
Signed-off-by: Charles E. Youse <charles.youse@intel.com>
This is the Wrong Thing(tm) with SMP enabled. Previously this
worked because interrupts would be re-enabled in the interrupt
entry sequence, but this is no longer the case.
Signed-off-by: Charles E. Youse <charles.youse@intel.com>
was ignoring the rest of the expression, though the effect was
harmless (including unreachable code in some builds).
Signed-off-by: Charles E. Youse <charles.youse@intel.com>
Trivial change to the Kconfig: the first 32 vectors are reserved,
so it's not possible to have 256 IRQ vectors. Change max to 224.
Signed-off-by: Charles E. Youse <charles.youse@intel.com>
Add duplicate per-CPU data structures (x86_cpuboot, tss, stacks, etc.)
for up to 4 total CPUs, add code in locore and z_arch_start_cpu().
The test board, qemu_x86_long, now defaults to 2 CPUs.
Signed-off-by: Charles E. Youse <charles.youse@intel.com>
Take a dummy first argument, so that the BSP entry point (z_x86_prep_c)
has the same signature as the AP entry point (smp_init_top).
Signed-off-by: Charles E. Youse <charles.youse@intel.com>
A new 'struct x86_cpuboot' is created as well as an instance called
'x86_cpuboot[]' which contains per-CPU boot data (initial stack,
entry function/arg, selectors, etc.). The locore now consults this
table to set up per-CPU registers, etc. during early boot.
Also, rename tss.c to cpu.c as its scope is growing.
Signed-off-by: Charles E. Youse <charles.youse@intel.com>
There's no need to qualify the 64-bit CS/DS selectors, and the GS and
TR selectors are renamed CPU0_GS and CPU0_TR as they are CPU-specific.
Signed-off-by: Charles E. Youse <charles.youse@intel.com>
In some places the code was being overly pedantic; e.g., there is no
need to load our own 32-bit descriptors because the loader's are fine
for our purposes. We can defer loading our own segments until 64-bit.
The sequence is re-ordered to faciliate code sharing between the BSP
and APs when SMP is enabled (all BSP-specific operations occur before
the per-CPU initialization).
Signed-off-by: Charles E. Youse <charles.youse@intel.com>
This is really just to facilitate CPU bootstrap code between
the BSP and the APs, moving the clear operation out of the way.
Signed-off-by: Charles E. Youse <charles.youse@intel.com>
In the general case, the local APIC can't be treated as a normal device
with a single boot-time initialization - on SMP systems, each CPU must
initialize its own. Hence the initialization proper is separated from
the device-driver initialization, and said initialization is called
from the early startup-assembly code when appropriate.
Signed-off-by: Charles E. Youse <charles.youse@intel.com>
The 32-bit and 64-bit assembly startup sequences share quite a
bunch of common code, so it's factored out into one file to avoid
repeating ourselves (and potentially falling out of sync).
Signed-off-by: Charles E. Youse <charles.youse@intel.com>
The linker script was missing symbols that defined the boundaries
of kernel memory segments (_image_rom_end, etc.). These are added
so that core/memmap.c can properly account for those segments.
Signed-off-by: Charles E. Youse <charles.youse@intel.com>
Elevate the previously 32-bit-only z_x86_prep_c() function to common
code, so both 32-bit and 64-bit arches now enter the kernel this way.
Minor changes to prep_c.c to make it build with the SMP scheduler on.
Signed-off-by: Charles E. Youse <charles.youse@intel.com>
And set qemu_x86_long board to build with CONFIG_SMP=y by default.
Apparently two benchmark tests - latency_measure and sys_kernel -
do not work with the SMP scheduler, so those tests are disabled.
Signed-off-by: Charles E. Youse <charles.youse@intel.com>
This patch is a preparatory step in enabling the MMU in
long mode; no steps are taken to implement long mode support.
We introduce struct x86_page_tables, which represents the
top-level data structure for page tables:
- For 32-bit, this will contain a four-entry page directory
pointer table (PDPT)
- For 64-bit, this will (eventually) contain a page map level 4
table (PML4)
In either case, this pointer value is what gets programmed into
CR3 to activate a set of page tables. There are extra bits in
CR3 to set for long mode, we'll get around to that later.
This abstraction will allow us to use the same APIs that work
with page tables in either mode, rather than hard-coding that
the top level data structure is a PDPT.
z_x86_mmu_validate() has been re-written to make it easier to
add another level of paging for long mode, to support 2MB
PDPT entries, and correctly validate regions which span PDPTE
entries.
Some MMU-related APIs moved out of 32-bit x86's arch.h into
mmustructs.h.
Signed-off-by: Andrew Boie <andrew.p.boie@intel.com>
Ioannis Glaropoulos