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kernel: tickless: Rename _Swap to allow creation of macro

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Future tickless kernel patches would be inserting some
code before call to Swap. To enable this it will create
a mcro named as the current _Swap which would call first
the tickless kernel code and then call the real __swap()

Jira: ZEP-339
Change-Id: Id778bfcee4f88982c958fcf22d7f04deb4bd572f
Signed-off-by: Ramesh Thomas <ramesh.thomas@intel.com>
This commit is contained in:
Ramesh Thomas 2017-04-06 15:30:27 -07:00 • committed by Anas Nashif
commit 62eea121b3
9 changed files with 70 additions and 68 deletions
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20
arch/riscv32/core/swap.S
View file

@ -9,18 +9,18 @@
#include <offsets_short.h>
/* exports */
GTEXT(_Swap)
GTEXT(__swap)
GTEXT(_thread_entry_wrapper)
/* Use ABI name of registers for the sake of simplicity */
/*
* unsigned int _Swap(unsigned int key)
* unsigned int __swap(unsigned int key)
*
* Always called with interrupts locked
* key is stored in a0 register
*/
SECTION_FUNC(exception.other, _Swap)
SECTION_FUNC(exception.other, __swap)
/* Make a system call to perform context switch */
ecall
@ -30,16 +30,16 @@ SECTION_FUNC(exception.other, _Swap)
* Restored register a0 contains IRQ lock state of thread.
*
* Prior to unlocking irq, load return value of
* _Swap to temp register t2 (from _thread_offset_to_swap_return_value).
* Normally, it should be -EAGAIN, unless someone has previously
* called _set_thread_return_value(..).
* __swap to temp register t2 (from
* _thread_offset_to_swap_return_value). Normally, it should be -EAGAIN,
* unless someone has previously called _set_thread_return_value(..).
*/
la t0, _kernel
/* Get pointer to _kernel.current */
lw t1, _kernel_offset_to_current(t0)
/* Load return value of _Swap function in temp register t2 */
/* Load return value of __swap function in temp register t2 */
lw t2, _thread_offset_to_swap_return_value(t1)
/*
@ -62,9 +62,9 @@ SECTION_FUNC(exception.other, _Swap)
SECTION_FUNC(TEXT, _thread_entry_wrapper)
/*
* _thread_entry_wrapper is called for every new thread upon the return
* of _Swap or ISR. Its address, as well as its input function arguments
* thread_entry_t, void *, void *, void * are restored from the thread
* stack (initialized via function _thread).
* of __swap or ISR. Its address, as well as its input function
* arguments thread_entry_t, void *, void *, void * are restored from
* the thread stack (initialized via function _thread).
* In this case, thread_entry_t, * void *, void * and void * are stored
* in registers a0, a1, a2 and a3. These registers are used as arguments
* to function _thread_entry. Hence, just call _thread_entry with