This adds the necessary bits to enable memory mapping thread
stacks on both x86 and x86_64. Note that currently these do
not support multi level mappings (e.g. demand paging and
running in virtual address space: qemu_x86/atom/virt board)
as the mapped stacks require actual physical addresses.
Signed-off-by: Daniel Leung <daniel.leung@intel.com>
In order to bring consistency in-tree, migrate all arch code to the new
prefix <zephyr/...>. Note that the conversion has been scripted, refer
to zephyrproject-rtos#45388 for more details.
Signed-off-by: Gerard Marull-Paretas <gerard.marull@nordicsemi.no>
When "eager FPU sharing" mode is enabled, FPU registers must be
initialised at the time of thread creation because the floating-point
context is always active and no further FPU initialisation is performed
later.
Note that, in case of the "lazy FPU sharing" mode, floating-point
context is inactive by default and the FPU is initialised when the
first floating-point instruction is executed.
Refer to the issue #44902 for more details.
Signed-off-by: Stephanos Ioannidis <root@stephanos.io>
This patch replaces ENOSYS into ENOTSUP to keep consistency with
the return value specification of k_float_enable().
Signed-off-by: Katsuhiro Suzuki <katsuhiro@katsuster.net>
This patch introduce new API to enable FPU of thread. This is pair of
existed k_float_disable() API. And also add empty arch_float_enable()
into each architectures that have arch_float_disable(). The arc and
riscv already implemented arch_float_enable() so I do not touch
these implementations.
Motivation: Current Zephyr implementation does not allow to use FPU
on main and other system threads like as work queue. Users need to
create an other thread with K_FP_REGS for floating point programs.
Users can use FPU more easily if they can enable FPU on running
threads.
Signed-off-by: Katsuhiro Suzuki <katsuhiro@katsuster.net>
The original idea of using a custom switch to main thread
function is to make sure the buffer to save floating point
registers are aligned correctly or else exception would be
raised when saving/restoring those registers. Since
the struct of the buffer is defined with alignment hint
to toolchain, the alignment will be enforced by toolchain
as long as the k_thread struct variable is a dedicated,
declared variable. So there is no need for the custom
switch to main thread function anymore.
This also allows the stack usage calculation of
the interrupt stack to function properly as the end of
the interrupt stack is not being used for the dummy
thread anymore.
Signed-off-by: Daniel Leung <daniel.leung@intel.com>
The x86 paging code has been rewritten to support another paging mode
and non-identity virtual mappings.
- Paging code now uses an array of paging level characteristics and
walks tables using for loops. This is opposed to having different
functions for every paging level and lots of #ifdefs. The code is
now more concise and adding new paging modes should be trivial.
- We now support 32-bit, PAE, and IA-32e page tables.
- The page tables created by gen_mmu.py are now installed at early
boot. There are no longer separate "flat" page tables. These tables
are mutable at any time.
- The x86_mmu code now has a private header. Many definitions that did
not need to be in public scope have been moved out of mmustructs.h
and either placed in the C file or in the private header.
- Improvements to dumping page table information, with the physical
mapping and flags all shown
- arch_mem_map() implemented
- x86 userspace/memory domain code ported to use the new
infrastructure.
- add logic for physical -> virtual instruction pointer transition,
including cleaning up identity mappings after this takes place.
Signed-off-by: Andrew Boie <andrew.p.boie@intel.com>
These stacks are appropriate for threads that run purely in
supervisor mode, and also as stacks for interrupt and exception
handling.
Two new arch defines are introduced:
- ARCH_KERNEL_STACK_GUARD_SIZE
- ARCH_KERNEL_STACK_OBJ_ALIGN
New public declaration macros:
- K_KERNEL_STACK_RESERVED
- K_KERNEL_STACK_EXTERN
- K_KERNEL_STACK_DEFINE
- K_KERNEL_STACK_ARRAY_DEFINE
- K_KERNEL_STACK_MEMBER
- K_KERNEL_STACK_SIZEOF
If user mode is not enabled, K_KERNEL_STACK_* and K_THREAD_STACK_*
are equivalent.
Separately generated privilege elevation stacks are now declared
like kernel stacks, removing the need for K_PRIVILEGE_STACK_ALIGN.
Signed-off-by: Andrew Boie <andrew.p.boie@intel.com>
This now takes a stack pointer as an argument with TLS
and random offsets accounted for properly.
Based on #24467 authored by Flavio Ceolin.
Signed-off-by: Andrew Boie <andrew.p.boie@intel.com>
The core kernel computes the initial stack pointer
for a thread, properly aligning it and subtracting out
any random offsets or thread-local storage areas.
arch_new_thread() no longer needs to make any calculations,
an initial stack frame may be placed at the bounds of
the new 'stack_ptr' parameter passed in. This parameter
replaces 'stack_size'.
thread->stack_info is now set before arch_new_thread()
is invoked, z_new_thread_init() has been removed.
The values populated may need to be adjusted on arches
which carve-out MPU guard space from the actual stack
buffer.
thread->stack_info now has a new member 'delta' which
indicates any offset applied for TLS or random offset.
It's used so the calculations don't need to be repeated
if the thread later drops to user mode.
CONFIG_INIT_STACKS logic is now performed inside
z_setup_new_thread(), before arch_new_thread() is called.
thread->stack_info is now defined as the canonical
user-accessible area within the stack object, including
random offsets and TLS. It will never include any
carved-out memory for MPU guards and must be updated at
runtime if guards are removed.
Available stack space is now optimized. Some arches may
need to significantly round up the buffer size to account
for page-level granularity or MPU power-of-two requirements.
This space is now accounted for and used by virtue of
the Z_THREAD_STACK_SIZE_ADJUST() call in z_setup_new_thread.
Signed-off-by: Andrew Boie <andrew.p.boie@intel.com>
MISRA-C wants the parameter names in a function implementaion
to match the names used by the header prototype.
Signed-off-by: Andrew Boie <andrew.p.boie@intel.com>
arch_new_thread() passes along the thread priority and option
flags, but these are already initialized in thread->base and
can be accessed there if needed.
Signed-off-by: Andrew Boie <andrew.p.boie@intel.com>
x86-32 thread objects require special alignment since they
contain a buffer that is passed to fxsave/fxrstor instructions.
This fell over if the dummy thread is created in a stack frame.
Implement a custom swap to main for x86 which still uses a
dummy thread, but in an unused part of the interrupt stack
with proper alignment.
Signed-off-by: Andrew Boie <andrew.p.boie@intel.com>
This commit renames the x86 Kconfig `CONFIG_{EAGER,LAZY}_FP_SHARING`
symbol to `CONFIG_{EAGER,LAZY}_FPU_SHARING`, in order to align with the
recent `CONFIG_FP_SHARING` to `CONFIG_FPU_SHARING` renaming.
Signed-off-by: Stephanos Ioannidis <root@stephanos.io>
This commit renames the Kconfig `FP_SHARING` symbol to `FPU_SHARING`,
since this symbol specifically refers to the hardware FPU sharing
support by means of FPU context preservation, and the "FP" prefix is
not fully descriptive of that; leaving room for ambiguity.
Signed-off-by: Stephanos Ioannidis <root@stephanos.io>
This commit renames the Kconfig `FLOAT` symbol to `FPU`, since this
symbol only indicates that the hardware Floating Point Unit (FPU) is
used and does not imply and/or indicate the general availability of
toolchain-level floating point support (i.e. this symbol is not
selected when building for an FPU-less platform that supports floating
point operations through the toolchain-provided software floating point
library).
Moreover, given that the symbol that indicates the availability of FPU
is named `CPU_HAS_FPU`, it only makes sense to use "FPU" in the name of
the symbol that enables the FPU.
Signed-off-by: Stephanos Ioannidis <root@stephanos.io>
This operation is formally defined as rounding down a potential
stack pointer value to meet CPU and ABI requirments.
This was previously defined ad-hoc as STACK_ROUND_DOWN().
A new architecture constant ARCH_STACK_PTR_ALIGN is added.
Z_STACK_PTR_ALIGN() is defined in terms of it. This used to
be inconsistently specified as STACK_ALIGN or STACK_PTR_ALIGN;
in the latter case, STACK_ALIGN meant something else, typically
a required alignment for the base of a stack buffer.
STACK_ROUND_UP() only used in practice by Risc-V, delete
elsewhere.
Signed-off-by: Andrew Boie <andrew.p.boie@intel.com>
The core kernel z_setup_new_thread() calls into arch_new_thread(),
which calls back into the core kernel via z_new_thread_init().
Move everything that doesn't have to be in z_new_thread_init() to
z_setup_new_thread() and convert to an inline function.
Signed-off-by: Andrew Boie <andrew.p.boie@intel.com>
These are now common code, all are related to user mode
threads. The rat's nest of ifdefs in ia32's arch_new_thread
has been greatly simplified, there is now just one hook
if user mode is turned on.
Signed-off-by: Andrew Boie <andrew.p.boie@intel.com>
z_x86_thread_page_tables_get() now works for both user
and supervisor threads, returning the kernel page tables
in the latter case. This API has been up-leveled to
a common header.
The per-thread privilege elevation stack initial stack
pointer, and the per-thread page table locations are no
longer computed from other values, and instead are stored
in thread->arch.
A problem where the wrong page tables were dumped out
on certain kinds of page faults has been fixed.
Signed-off-by: Andrew Boie <andrew.p.boie@intel.com>
This is causing problems, as if we create a thread in
a system call we will *not* be using the kernel page
tables if CONFIG_KPTI=n, resulting in a crash when
the later call to copy_page_tables() tries to initialize
the PDPT (which is in the same page as the privilege
stack).
Just don't fiddle with this page's permissions; we don't
need it as a guard area anyway since we have a stack
guard placed immediately before it, and this page
is unused if user mode isn't active.
Signed-off-by: Andrew Boie <andrew.p.boie@intel.com>
Promote the private z_arch_* namespace, which specifies
the interface between the core kernel and the
architecture code, to a new top-level namespace named
arch_*.
This allows our documentation generation to create
online documentation for this set of interfaces,
and this set of interfaces is worth treating in a
more formal way anyway.
Signed-off-by: Andrew Boie <andrew.p.boie@intel.com>
This commit refactors kernel and arch headers to establish a boundary
between private and public interface headers.
The refactoring strategy used in this commit is detailed in the issue
This commit introduces the following major changes:
1. Establish a clear boundary between private and public headers by
removing "kernel/include" and "arch/*/include" from the global
include paths. Ideally, only kernel/ and arch/*/ source files should
reference the headers in these directories. If these headers must be
used by a component, these include paths shall be manually added to
the CMakeLists.txt file of the component. This is intended to
discourage applications from including private kernel and arch
headers either knowingly and unknowingly.
- kernel/include/ (PRIVATE)
This directory contains the private headers that provide private
kernel definitions which should not be visible outside the kernel
and arch source code. All public kernel definitions must be added
to an appropriate header located under include/.
- arch/*/include/ (PRIVATE)
This directory contains the private headers that provide private
architecture-specific definitions which should not be visible
outside the arch and kernel source code. All public architecture-
specific definitions must be added to an appropriate header located
under include/arch/*/.
- include/ AND include/sys/ (PUBLIC)
This directory contains the public headers that provide public
kernel definitions which can be referenced by both kernel and
application code.
- include/arch/*/ (PUBLIC)
This directory contains the public headers that provide public
architecture-specific definitions which can be referenced by both
kernel and application code.
2. Split arch_interface.h into "kernel-to-arch interface" and "public
arch interface" divisions.
- kernel/include/kernel_arch_interface.h
* provides private "kernel-to-arch interface" definition.
* includes arch/*/include/kernel_arch_func.h to ensure that the
interface function implementations are always available.
* includes sys/arch_interface.h so that public arch interface
definitions are automatically included when including this file.
- arch/*/include/kernel_arch_func.h
* provides architecture-specific "kernel-to-arch interface"
implementation.
* only the functions that will be used in kernel and arch source
files are defined here.
- include/sys/arch_interface.h
* provides "public arch interface" definition.
* includes include/arch/arch_inlines.h to ensure that the
architecture-specific public inline interface function
implementations are always available.
- include/arch/arch_inlines.h
* includes architecture-specific arch_inlines.h in
include/arch/*/arch_inline.h.
- include/arch/*/arch_inline.h
* provides architecture-specific "public arch interface" inline
function implementation.
* supersedes include/sys/arch_inline.h.
3. Refactor kernel and the existing architecture implementations.
- Remove circular dependency of kernel and arch headers. The
following general rules should be observed:
* Never include any private headers from public headers
* Never include kernel_internal.h in kernel_arch_data.h
* Always include kernel_arch_data.h from kernel_arch_func.h
* Never include kernel.h from kernel_struct.h either directly or
indirectly. Only add the kernel structures that must be referenced
from public arch headers in this file.
- Relocate syscall_handler.h to include/ so it can be used in the
public code. This is necessary because many user-mode public codes
reference the functions defined in this header.
- Relocate kernel_arch_thread.h to include/arch/*/thread.h. This is
necessary to provide architecture-specific thread definition for
'struct k_thread' in kernel.h.
- Remove any private header dependencies from public headers using
the following methods:
* If dependency is not required, simply omit
* If dependency is required,
- Relocate a portion of the required dependencies from the
private header to an appropriate public header OR
- Relocate the required private header to make it public.
This commit supersedes #20047, addresses #19666, and fixes#3056.
Signed-off-by: Stephanos Ioannidis <root@stephanos.io>
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 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>
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>
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>
This is part of the core kernel -> architecture interface
and should have a leading prefix z_arch_.
Signed-off-by: Andrew Boie <andrew.p.boie@intel.com>
There are not enough bits in k_thread.thread_state with SMP enabled,
and the field is (should be) private to the scheduler, anyway. So
move state bits to the _thread_arch where they belong.
While we're at it, refactor some offset data w/r/t _thread_arch
because it can be shared between 32- and 64-bit subarches.
Signed-off-by: Charles E. Youse <charles.youse@intel.com>
Makes the code that defines stacks, and code referencing
areas within the stack object, much clearer.
Signed-off-by: Andrew Boie <andrew.p.boie@intel.com>
Previously, context switching on x86 with memory protection
enabled involved walking the page tables, de-configuring all
the partitions in the outgoing thread's memory domain, and
then configuring all the partitions in the incoming thread's
domain, on a global set of page tables.
We now have a much faster design. Each thread has reserved in
its stack object a number of pages to store page directories
and page tables pertaining to the system RAM area. Each
thread also has a toplevel PDPT which is configured to use
the per-thread tables for system RAM, and the global tables
for the rest of the address space.
The result of this is on context switch, at most we just have
to update the CR3 register to the incoming thread's PDPT.
The x86_mmu_api test was making too many assumptions and has
been adjusted to work with the new design.
Signed-off-by: Andrew Boie <andrew.p.boie@intel.com>
The current API was assuming too much, in that it expected that
arch-specific memory domain configuration is only maintained
in some global area, and updates to domains that are not currently
active have no effect.
This was true when all memory domain state was tracked in page
tables or MPU registers, but no longer works when arch-specific
memory management information is stored in thread-specific areas.
This is needed for: #13441#13074#15135
Signed-off-by: Andrew Boie <andrew.p.boie@intel.com>
Currently page tables have to be re-computed in
an expensive operation on context switch. Here we
reserve some room in the page tables such that
we can have per-thread page table data, which will
be much simpler to update on context switch at
the expense of memory.
Signed-off-by: Andrew Boie <andrew.p.boie@intel.com>
Has the same effect of catching stack overflows, but
makes debugging with GDB simpler since we won't get
errors when inspecting such regions. Making these
areas non-present was more than we needed, read-only
is sufficient.
Signed-off-by: Andrew Boie <andrew.p.boie@intel.com>
It looks like, at some point in the past, initializing thread stacks
was the responsibility of the arch layer. After that was centralized,
we forgot to remove the related conditional header inclusion. Fixed.
Signed-off-by: Charles E. Youse <charles.youse@intel.com>
For the x86 architecture the z_arch_float_disable() is only
implemented when building with CONFIG_LAZY_FP_SHARING, so we
make z_arch_float_disable() return -ENOSYS when we build with
FLOAT and FP_SHARING but on an x86 platform where
LAZY_FP_SHARING is not supported.
Signed-off-by: Ioannis Glaropoulos <Ioannis.Glaropoulos@nordicsemi.no>
move misc/printk.h to sys/printk.h and
create a shim for backward-compatibility.
No functional changes to the headers.
A warning in the shim can be controlled with CONFIG_COMPAT_INCLUDES.
Related to #16539
Signed-off-by: Anas Nashif <anas.nashif@intel.com>
Previously the existing EFLAGS was used as a base which was
then manipulated accordingly. This is unnecessary as the bits
preserved contain no useful state related to the new thread.
Signed-off-by: Charles E. Youse <charles.youse@intel.com>
Create source directory for IA32-subarch specific files, and move
qualifying files to that subdirectory.
Signed-off-by: Charles E. Youse <charles.youse@intel.com>
