6e27478c3d
This code had one purpose only, feed timing information into a test and was not used by anything else. The custom trace points unfortunatly were not accurate and this test was delivering informatin that conflicted with other tests we have due to placement of such trace points in the architecture and kernel code. For such measurements we are planning to use the tracing functionality in a special mode that would be used for metrics without polluting the architecture and kernel code with additional tracing and timing code. Furthermore, much of the assembly code used had issues. Signed-off-by: Anas Nashif <anas.nashif@intel.com> Signed-off-by: Daniel Leung <daniel.leung@intel.com>
161 lines
3.5 KiB
ArmAsm
161 lines
3.5 KiB
ArmAsm
/*
|
|
* Copyright (c) 2019 Synopsys.
|
|
*
|
|
* SPDX-License-Identifier: Apache-2.0
|
|
*/
|
|
|
|
/**
|
|
* @file
|
|
* @brief Thread context switching
|
|
*
|
|
* This module implements the routines necessary for thread context switching
|
|
* on ARCv2 CPUs.
|
|
*
|
|
* See isr_wrapper.S for details.
|
|
*/
|
|
|
|
#include <kernel_structs.h>
|
|
#include <offsets_short.h>
|
|
#include <toolchain.h>
|
|
#include <linker/sections.h>
|
|
#include <arch/cpu.h>
|
|
#include <v2/irq.h>
|
|
#include <swap_macros.h>
|
|
|
|
GTEXT(z_arc_switch)
|
|
|
|
/**
|
|
*
|
|
* @brief Initiate a cooperative context switch
|
|
*
|
|
* The arch_switch routine is invoked by various kernel services to effect
|
|
* a cooperative context switch. Prior to invoking arch_switch, the caller
|
|
* disables interrupts via irq_lock()
|
|
|
|
* Given that arch_switch() is called to effect a cooperative context switch,
|
|
* the caller-saved integer registers are saved on the stack by the function
|
|
* call preamble to arch_switch. This creates a custom stack frame that will
|
|
* be popped when returning from arch_switch, but is not suitable for handling
|
|
* a return from an exception. Thus, the fact that the thread is pending because
|
|
* of a cooperative call to arch_switch() has to be recorded via the
|
|
* _CAUSE_COOP code in the relinquish_cause of the thread's k_thread structure.
|
|
* The _rirq_exit()/_firq_exit() code will take care of doing the right thing
|
|
* to restore the thread status.
|
|
*
|
|
* When arch_switch() is invoked, we know the decision to perform a context
|
|
* switch or not has already been taken and a context switch must happen.
|
|
*
|
|
*
|
|
* C function prototype:
|
|
*
|
|
* void arch_switch(void *switch_to, void **switched_from);
|
|
*
|
|
*/
|
|
|
|
SECTION_FUNC(TEXT, z_arc_switch)
|
|
|
|
/*
|
|
* r0 = new_thread->switch_handle = switch_to thread,
|
|
* r1 = &old_thread->switch_handle
|
|
* get old_thread from r1
|
|
*/
|
|
|
|
sub r2, r1, ___thread_t_switch_handle_OFFSET
|
|
|
|
|
|
st _CAUSE_COOP, [r2, _thread_offset_to_relinquish_cause]
|
|
|
|
/*
|
|
* Save status32 and blink on the stack before the callee-saved registers.
|
|
* This is the same layout as the start of an IRQ stack frame.
|
|
*/
|
|
lr r3, [_ARC_V2_STATUS32]
|
|
push_s r3
|
|
|
|
#ifdef CONFIG_ARC_HAS_SECURE
|
|
#ifdef CONFIG_ARC_SECURE_FIRMWARE
|
|
lr r3, [_ARC_V2_SEC_STAT]
|
|
#else
|
|
mov_s r3, 0
|
|
#endif
|
|
push_s r3
|
|
#endif
|
|
|
|
push_s blink
|
|
|
|
_store_old_thread_callee_regs
|
|
|
|
/* disable stack checking here, as sp will be changed to target
|
|
* thread'sp
|
|
*/
|
|
_disable_stack_checking r3
|
|
|
|
mov_s r2, r0
|
|
|
|
_load_new_thread_callee_regs
|
|
|
|
breq r3, _CAUSE_RIRQ, _switch_return_from_rirq
|
|
nop_s
|
|
breq r3, _CAUSE_FIRQ, _switch_return_from_firq
|
|
nop_s
|
|
|
|
/* fall through to _switch_return_from_coop */
|
|
|
|
.align 4
|
|
_switch_return_from_coop:
|
|
|
|
pop_s blink /* pc into blink */
|
|
#ifdef CONFIG_ARC_HAS_SECURE
|
|
pop_s r3 /* pop SEC_STAT */
|
|
#ifdef CONFIG_ARC_SECURE_FIRMWARE
|
|
sflag r3
|
|
#endif
|
|
#endif
|
|
pop_s r3 /* status32 into r3 */
|
|
kflag r3 /* write status32 */
|
|
|
|
#ifdef CONFIG_TRACING
|
|
push_s blink
|
|
|
|
bl sys_trace_thread_switched_in
|
|
|
|
pop_s blink
|
|
#endif
|
|
j_s [blink]
|
|
|
|
|
|
.align 4
|
|
_switch_return_from_rirq:
|
|
_switch_return_from_firq:
|
|
|
|
_set_misc_regs_irq_switch_from_irq
|
|
|
|
/* use lowest interrupt priority to simulate
|
|
* a interrupt return to load left regs of new
|
|
* thread
|
|
*/
|
|
|
|
lr r3, [_ARC_V2_AUX_IRQ_ACT]
|
|
#ifdef CONFIG_ARC_SECURE_FIRMWARE
|
|
or r3, r3, (1 << (ARC_N_IRQ_START_LEVEL - 1))
|
|
#else
|
|
or r3, r3, (1 << (CONFIG_NUM_IRQ_PRIO_LEVELS - 1))
|
|
#endif
|
|
|
|
#ifdef CONFIG_ARC_NORMAL_FIRMWARE
|
|
mov_s r0, _ARC_V2_AUX_IRQ_ACT
|
|
mov_s r1, r3
|
|
mov_s r6, ARC_S_CALL_AUX_WRITE
|
|
sjli SJLI_CALL_ARC_SECURE
|
|
#else
|
|
sr r3, [_ARC_V2_AUX_IRQ_ACT]
|
|
#endif
|
|
#ifdef CONFIG_TRACING
|
|
push_s blink
|
|
|
|
bl sys_trace_thread_switched_in
|
|
|
|
pop_s blink
|
|
#endif
|
|
rtie
|