2d7460482d
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>
117 lines
3.4 KiB
C
117 lines
3.4 KiB
C
/*
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* Copyright (c) 2017 Intel Corporation
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*
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* SPDX-License-Identifier: Apache-2.0
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*/
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/**
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* @file
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* @brief Per-arch thread definition
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*
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* This file contains definitions for
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*
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* struct _thread_arch
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* struct _callee_saved
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*
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* necessary to instantiate instances of struct k_thread.
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*/
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#ifndef ZEPHYR_INCLUDE_ARCH_XTENSA_THREAD_H_
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#define ZEPHYR_INCLUDE_ARCH_XTENSA_THREAD_H_
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#ifndef _ASMLANGUAGE
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#include <zephyr/types.h>
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#include <arch/xtensa/xtensa_context.h>
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/*
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* The following structure defines the set of 'non-volatile' integer registers.
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* These registers must be preserved by a called C function. These are the
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* only registers that need to be saved/restored when a cooperative context
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* switch occurs.
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*/
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struct _callee_saved {
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/*
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* The following registers are considered non-volatile, i.e.
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* callee-saved, but their values are pushed onto the stack rather than
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* stored in the k_thread structure:
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*/
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u32_t retval; /* a2 */
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XtExcFrame *topOfStack; /* a1 = sp */
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};
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typedef struct _callee_saved _callee_saved_t;
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/*
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* The following structure defines the set of 'non-volatile' x87 FPU/MMX/SSE
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* registers. These registers must be preserved by a called C function.
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* These are the only registers that need to be saved/restored when a
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* cooperative context switch occurs.
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*/
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typedef struct s_coopCoprocReg {
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/*
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* This structure intentionally left blank. Coprocessor's registers are
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* all 'volatile' and saved using the lazy context switch mechanism.
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*/
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} tCoopCoprocReg;
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/*
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* The following structure defines the set of 'volatile' x87 FPU/MMX/SSE
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* registers. These registers need not be preserved by a called C function.
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* Given that they are not preserved across function calls, they must be
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* save/restored (along with s_coopCoprocReg) when a preemptive context switch
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* occurs.
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*/
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typedef struct s_preempCoprocReg {
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/*
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* This structure reserved coprocessor control and save area memory.
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*/
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#if XCHAL_CP_NUM > 0
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char __aligned(4) cpStack[XT_CP_SIZE];
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#endif
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} tPreempCoprocReg;
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/*
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* The thread control structure definition. It contains the
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* various fields to manage a _single_ thread.
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*/
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struct _thread_arch {
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/*
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* See the above flag definitions above for valid bit settings. This
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* field must remain near the start of struct k_thread, specifically
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* before any #ifdef'ed fields since the host tools currently use a
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* fixed offset to read the 'flags' field.
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*/
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u32_t flags;
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#ifdef CONFIG_ERRNO
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int errno_var;
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#endif
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/*
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* The location of all floating point related structures/fields MUST be
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* located at the end of struct k_thread. This way only the threads
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* that actually utilize non-integer capabilities need to account for
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* the increased memory required for storing FP state when sizing
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* stacks.
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*
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* Given that stacks "grow down" on Xtensa, and the k_thread is located
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* at the start of a thread's "workspace" memory, the stacks of threads
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* that do not utilize floating point instruction can effectively
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* consume the memory occupied by the 'tCoopCoprocReg' and
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* 'tPreempCoprocReg' structures without ill effect.
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*/
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/* non-volatile coprocessor's register storage */
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tCoopCoprocReg coopCoprocReg;
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/* volatile coprocessor's register storage */
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tPreempCoprocReg preempCoprocReg;
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};
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typedef struct _thread_arch _thread_arch_t;
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#endif /* _ASMLANGUAGE */
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#endif /* ZEPHYR_INCLUDE_ARCH_XTENSA_THREAD_H_ */
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