| /* |
| * Copyright (c) 2016 Intel Corporation |
| * |
| * SPDX-License-Identifier: Apache-2.0 |
| */ |
| |
| #include <arch/nios2/asm.h> |
| #include <kernel_structs.h> |
| #include <offsets_short.h> |
| |
| /* exports */ |
| GTEXT(__swap) |
| GTEXT(_thread_entry_wrapper) |
| |
| /* imports */ |
| GTEXT(_sys_k_event_logger_context_switch) |
| GTEXT(_k_neg_eagain) |
| |
| /* unsigned int __swap(unsigned int key) |
| * |
| * Always called with interrupts locked |
| */ |
| SECTION_FUNC(exception.other, __swap) |
| |
| /* Get a reference to _kernel in r10 */ |
| movhi r10, %hi(_kernel) |
| ori r10, r10, %lo(_kernel) |
| |
| /* Get the pointer to kernel->current */ |
| ldw r11, _kernel_offset_to_current(r10) |
| |
| /* Store all the callee saved registers. We either got here via |
| * an exception or from a cooperative invocation of __swap() from C |
| * domain, so all the caller-saved registers have already been |
| * saved by the exception asm or the calling C code already. |
| */ |
| stw r16, _thread_offset_to_r16(r11) |
| stw r17, _thread_offset_to_r17(r11) |
| stw r18, _thread_offset_to_r18(r11) |
| stw r19, _thread_offset_to_r19(r11) |
| stw r20, _thread_offset_to_r20(r11) |
| stw r21, _thread_offset_to_r21(r11) |
| stw r22, _thread_offset_to_r22(r11) |
| stw r23, _thread_offset_to_r23(r11) |
| stw r28, _thread_offset_to_r28(r11) |
| stw ra, _thread_offset_to_ra(r11) |
| stw sp, _thread_offset_to_sp(r11) |
| |
| /* r4 has the 'key' argument which is the result of irq_lock() |
| * before this was called |
| */ |
| stw r4, _thread_offset_to_key(r11) |
| |
| /* Populate default return value */ |
| movhi r5, %hi(_k_neg_eagain) |
| ori r5, r5, %lo(_k_neg_eagain) |
| ldw r4, (r5) |
| stw r4, _thread_offset_to_retval(r11) |
| |
| #if CONFIG_KERNEL_EVENT_LOGGER_CONTEXT_SWITCH |
| call _sys_k_event_logger_context_switch |
| /* restore caller-saved r10 */ |
| movhi r10, %hi(_kernel) |
| ori r10, r10, %lo(_kernel) |
| #endif |
| |
| /* get cached thread to run */ |
| ldw r2, _kernel_offset_to_ready_q_cache(r10) |
| |
| /* At this point r2 points to the next thread to be swapped in */ |
| |
| /* the thread to be swapped in is now the current thread */ |
| stw r2, _kernel_offset_to_current(r10) |
| |
| /* Restore callee-saved registers and switch to the incoming |
| * thread's stack |
| */ |
| ldw r16, _thread_offset_to_r16(r2) |
| ldw r17, _thread_offset_to_r17(r2) |
| ldw r18, _thread_offset_to_r18(r2) |
| ldw r19, _thread_offset_to_r19(r2) |
| ldw r20, _thread_offset_to_r20(r2) |
| ldw r21, _thread_offset_to_r21(r2) |
| ldw r22, _thread_offset_to_r22(r2) |
| ldw r23, _thread_offset_to_r23(r2) |
| ldw r28, _thread_offset_to_r28(r2) |
| ldw ra, _thread_offset_to_ra(r2) |
| ldw sp, _thread_offset_to_sp(r2) |
| |
| /* We need to irq_unlock(current->coopReg.key); |
| * key was supplied as argument to __swap(). Fetch it. |
| */ |
| ldw r3, _thread_offset_to_key(r2) |
| |
| /* |
| * Load return value into r2 (return value register). -EAGAIN unless |
| * someone previously called _set_thread_return_value(). Do this before |
| * we potentially unlock interrupts. |
| */ |
| ldw r2, _thread_offset_to_retval(r2) |
| |
| /* Now do irq_unlock(current->coopReg.key) */ |
| #if (ALT_CPU_NUM_OF_SHADOW_REG_SETS > 0) || \ |
| (defined ALT_CPU_EIC_PRESENT) || \ |
| (defined ALT_CPU_MMU_PRESENT) || \ |
| (defined ALT_CPU_MPU_PRESENT) |
| andi r3, r3, NIOS2_STATUS_PIE_MSK |
| beq r3, zero, no_unlock |
| rdctl r3, status |
| ori r3, r3, NIOS2_STATUS_PIE_MSK |
| wrctl status, r3 |
| |
| no_unlock: |
| #else |
| wrctl status, r3 |
| #endif |
| ret |
| |
| |
| /* void _thread_entry_wrapper(void) |
| */ |
| SECTION_FUNC(TEXT, _thread_entry_wrapper) |
| /* This all corresponds to struct init_stack_frame defined in |
| * thread.c. We need to take this stuff off the stack and put |
| * it in the apporpriate registers |
| */ |
| |
| /* Can't return from here, just put NULL in ra */ |
| movi ra, 0 |
| |
| /* Calling convention has first 4 arguments in registers r4-r7. */ |
| ldw r4, 0(sp) |
| ldw r5, 4(sp) |
| ldw r6, 8(sp) |
| ldw r7, 12(sp) |
| |
| /* pop all the stuff that we just loaded into registers */ |
| addi sp, sp, 16 |
| |
| call _thread_entry |
| |