Commit Graph

18 Commits

Author SHA1 Message Date
Alexandre Mergnat 542a7fa25d arch: riscv: add memory protection support
The IRQ handler has had a major changes to manage syscall, reschedule
and interrupt from user thread and stack guard.

Add userspace support:
- Use a global variable to know if the current execution is user or
  machine. The location of this variable is read only for all user
  thread and read/write for kernel thread.
- Memory shared is supported.
- Use dynamic allocation to optimize PMP slot usage. If the area size
  is a power of 2, only one PMP slot is used, else 2 are used.

Add stack guard support:
- Use MPRV bit to force PMP rules to machine mode execution.
- IRQ stack have a locked stack guard to avoid re-write PMP
  configuration registers for each interruption and then win some
  cycle.
- The IRQ stack is used as "temporary" stack at the beginning of IRQ
  handler to save current ESF. That avoid to trigger write fault on
  thread stack during store ESF which that call IRQ handler to
  infinity.
- A stack guard is also setup for privileged stack of a user thread.

Thread:
- A PMP setup is specific to each thread. PMP setup are saved in each
  thread structure to improve reschedule performance.

Signed-off-by: Alexandre Mergnat <amergnat@baylibre.com>
Reviewed-by: Nicolas Royer <nroyer@baylibre.com>
2020-11-09 15:37:11 -05:00
Alexandre Mergnat 18962e4ab8 arch: riscv: add pmp support
- Set some helper function to write/clear/print PMP config registers.
- Add support for different PMP slot size function to core/board.

Signed-off-by: Alexandre Mergnat <amergnat@baylibre.com>
2020-11-09 15:37:11 -05:00
Andrew Boie 8b4b0d6264 kernel: z_interrupt_stacks are now kernel stacks
This will save memory on many platforms that enable
user mode.

Signed-off-by: Andrew Boie <andrew.p.boie@intel.com>
2020-07-30 21:11:14 -04:00
Andrew Boie a203d21962 kernel: remove legacy fields in _kernel
UP should just use _kernel.cpus[0].

Signed-off-by: Andrew Boie <andrew.p.boie@intel.com>
2020-05-08 17:42:49 +02:00
Stephanos Ioannidis aaf93205bb kconfig: Rename CONFIG_FP_SHARING to CONFIG_FPU_SHARING
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>
2020-05-08 10:58:33 +02:00
Stephanos Ioannidis 0e6ede8929 kconfig: Rename CONFIG_FLOAT to CONFIG_FPU
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>
2020-04-27 19:03:44 +02:00
Corey Wharton 58232d58e0 riscv: Add support for floating point
This change adds full shared floating point support for the RISCV
architecture with minimal impact on threads with floating point
support not enabled.

Signed-off-by: Corey Wharton <coreyw7@fb.com>
2020-04-22 16:39:48 -07:00
Andrew Boie 80a0d9d16b kernel: interrupt/idle stacks/threads as array
The set of interrupt stacks is now expressed as an array. We
also define the idle threads and their associated stacks this
way. This allows for iteration in cases where we have multiple
CPUs.

There is now a centralized declaration in kernel_internal.h.

On uniprocessor systems, z_interrupt_stacks has one element
and can be used in the same way as _interrupt_stack.

The IRQ stack for CPU 0 is now set in init.c instead of in
arch code.

The extern definition of the main thread stack is now removed,
this doesn't need to be in a header.

Signed-off-by: Andrew Boie <andrew.p.boie@intel.com>
2020-03-16 23:17:36 +02:00
Andrew Boie 4f77c2ad53 kernel: rename z_arch_ to arch_
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>
2019-11-07 15:21:46 -08:00
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 54506b5a9b arches: fix z_arch_is_in_isr() defintion
For some reason these were implemented as macros when they
should be inline functions.

Signed-off-by: Andrew Boie <andrew.p.boie@intel.com>
2019-10-09 09:14:18 -04:00
Andrew Boie f6fb634b89 kernel: rename kernel_arch_init()
This is part of the core kernel -> architecture interface and
has been renamed z_arch_kernel_init().

Signed-off-by: Andrew Boie <andrew.p.boie@intel.com>
2019-09-30 15:25:55 -04:00
Andrew Boie 4ad9f687df kernel: rename thread return value functions
z_set_thread_return_value is part of the core kernel -> arch
interface and has been renamed to z_arch_thread_return_value_set.

z_set_thread_return_value_with_data renamed to
z_thread_return_value_set_with_data for consistency.

Signed-off-by: Andrew Boie <andrew.p.boie@intel.com>
2019-09-30 15:25:55 -04:00
Andrew Boie 07525a3d54 kernel: add arch interface for idle functions
k_cpu_idle() and k_cpu_atomic_idle() were being directly
implemented by arch code.

Rename these implementations to z_arch_cpu_idle() and
z_arch_cpu_atomic_idle(), and call them from new inline
function definitions in kernel.h.

Signed-off-by: Andrew Boie <andrew.p.boie@intel.com>
2019-09-30 15:25:55 -04:00
Andrew Boie e1ec59f9c2 kernel: renamespace z_is_in_isr()
This is part of the core kernel -> architecture interface
and is appropriately renamed z_arch_is_in_isr().

References from test cases changed to k_is_in_isr().

Signed-off-by: Andrew Boie <andrew.p.boie@intel.com>
2019-09-30 15:25:55 -04:00
Peter Bigot 43fc6a7eff arch/riscv: rearrange for standard use of extern "C"
Consistently place C++ use of extern "C" after all include directives,
within the negative branch of _ASMLANGUAGE if used.

Remove extern "C" support from files that don't declare objects or
functions.

Background from issue #17997:

Declarations that use C linkage should be placed within extern "C"
so the language linkage is correct when the header is included by
a C++ compiler.

Similarly #include directives should be outside the extern "C" to
ensure the language-specific default linkage is applied to any
declarations provided by the included header.

See: https://en.cppreference.com/w/cpp/language/language_linkage
Signed-off-by: Peter Bigot <peter.bigot@nordicsemi.no>
2019-08-18 16:20:10 +02:00
Nicolas Pitre 0440a815a9 riscv: make core code 64-bit compatible
There are two aspects to this: CPU registers are twice as big, and the
load and store instructions must use the 'd' suffix instead of the 'w'
one. To abstract register differences, we simply use a ulong_t instead
of u32_t given that RISC-V is either ILP32 or LP64. And the relevant
lw/sw instructions are replaced by LR/SR (load/store register) that get
defined as either lw/sw or ld/sd. Finally a few constants to deal with
register offsets are also provided.

Signed-off-by: Nicolas Pitre <npitre@baylibre.com>
2019-08-02 13:54:48 -07:00
Nicolas Pitre 1f4b5ddd0f riscv32: rename to riscv
With the upcoming riscv64 support, it is best to use "riscv" as the
subdirectory name and common symbols as riscv32 and riscv64 support
code is almost identical. Then later decide whether 32-bit or 64-bit
compilation is wanted.

Redirects for the web documentation are also included.

Then zephyrbot complained about this:

"
New files added that are not covered in CODEOWNERS:

dts/riscv/microsemi-miv.dtsi
dts/riscv/riscv32-fe310.dtsi

Please add one or more entries in the CODEOWNERS file to cover
those files
"

So I assigned them to those who created them. Feel free to readjust
as necessary.

Signed-off-by: Nicolas Pitre <npitre@baylibre.com>
2019-08-02 13:54:48 -07:00