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7 commits

Author SHA1 Message Date
Stephanos Ioannidis
2d7460482d headers: Refactor kernel and arch headers.
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>
2019-11-06 16:07:32 -08:00
Andrew Boie
f82beb984d x86: remove unused thread arch member
The PDPT was moved to the stack area since it has alignment
requirements, but never removed from here.

Signed-off-by: Andrew Boie <andrew.p.boie@intel.com>
2019-10-19 20:40:26 -07:00
Andrew Boie
e3ab43580c x86: move mmustructs.h
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>
2019-10-14 11:49:39 -07:00
Andrew Boie
61901ccb4c kernel: rename z_new_thread()
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>
2019-09-30 15:25:55 -04:00
Charles E. Youse
a95c94cfe2 arch/x86/ia32: move IA32 thread state to _thread_arch
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>
2019-09-20 14:31:18 -04:00
Andrew Boie
8014e075f4 x86: use per-thread page tables
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>
2019-08-05 13:25:50 +02:00
Charles E. Youse
f40fe36ca6 arch/x86: refactor kernel_arch_thread.h
This data is subarchitecture-specific, so move it to ia32/
and add a layer of indirection at the architecture level.

Signed-off-by: Charles E. Youse <charles.youse@intel.com>
2019-07-03 20:01:17 -04:00