| /* |
| * Copyright (c) 2016 Intel Corporation |
| * |
| * Licensed under the Apache License, Version 2.0 (the "License"); |
| * you may not use this file except in compliance with the License. |
| * You may obtain a copy of the License at |
| * |
| * http://www.apache.org/licenses/LICENSE-2.0 |
| * |
| * Unless required by applicable law or agreed to in writing, software |
| * distributed under the License is distributed on an "AS IS" BASIS, |
| * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. |
| * See the License for the specific language governing permissions and |
| * limitations under the License. |
| */ |
| |
| #define _ASMLANGUAGE |
| #include <arch/nios2/asm.h> |
| #include <nano_private.h> |
| #include <offsets.h> |
| |
| /* exports */ |
| GTEXT(_Swap) |
| GTEXT(_thread_entry_wrapper) |
| |
| /* imports */ |
| GTEXT(_sys_k_event_logger_context_switch) |
| |
| /* unsigned int _Swap(unsigned int key) |
| * |
| * Always called with interrupts locked |
| */ |
| SECTION_FUNC(exception.other, _Swap) |
| |
| /* Get a reference to _nanokernel in r10 */ |
| movhi r10, %hi(_nanokernel) |
| ori r10, r10, %lo(_nanokernel) |
| |
| /* Get the pointer to nanokernel->current */ |
| ldw r11, __tNANO_current_OFFSET(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, __tTCS_coopReg_OFFSET + __t_coop_r16_OFFSET(r11) |
| stw r17, __tTCS_coopReg_OFFSET + __t_coop_r17_OFFSET(r11) |
| stw r18, __tTCS_coopReg_OFFSET + __t_coop_r18_OFFSET(r11) |
| stw r19, __tTCS_coopReg_OFFSET + __t_coop_r19_OFFSET(r11) |
| stw r20, __tTCS_coopReg_OFFSET + __t_coop_r20_OFFSET(r11) |
| stw r21, __tTCS_coopReg_OFFSET + __t_coop_r21_OFFSET(r11) |
| stw r22, __tTCS_coopReg_OFFSET + __t_coop_r22_OFFSET(r11) |
| stw r23, __tTCS_coopReg_OFFSET + __t_coop_r23_OFFSET(r11) |
| stw r28, __tTCS_coopReg_OFFSET + __t_coop_r28_OFFSET(r11) |
| stw ra, __tTCS_coopReg_OFFSET + __t_coop_ra_OFFSET(r11) |
| stw sp, __tTCS_coopReg_OFFSET + __t_coop_sp_OFFSET(r11) |
| |
| /* r4 has the 'key' argument which is the result of irq_lock() |
| * before this was called |
| */ |
| stw r4, __tTCS_coopReg_OFFSET + __t_coop_key_OFFSET(r11) |
| |
| #if CONFIG_KERNEL_EVENT_LOGGER_CONTEXT_SWITCH |
| call _sys_k_event_logger_context_switch |
| /* Restore caller-saved r10. We could have stuck its value |
| * onto the stack, but less instructions to just use immediates |
| */ |
| movhi r10, %hi(_nanokernel) |
| ori r10, r10, %lo(_nanokernel) |
| #endif |
| |
| /* Find the next context to run. Choose _nanokernel.fiber |
| * if non-NULL */ |
| ldw r11, __tNANO_fiber_OFFSET(r10) |
| beq r11, zero, not_fiber |
| |
| /* _nanokernel.fiber = _nanokernel.fiber->link */ |
| ldw r14, __tTCS_link_OFFSET(r11) |
| stw r14, __tNANO_fiber_OFFSET(r10) |
| br next_chosen |
| |
| BRANCH_LABEL(not_fiber) |
| /* Fiber was NULL, we'll choose nanokernel.task */ |
| ldw r11, __tNANO_task_OFFSET(r10) |
| |
| BRANCH_LABEL(next_chosen) |
| /* Set _nanokernel.current to value we chose for r11 */ |
| stw r11, __tNANO_current_OFFSET(r10) |
| |
| /* Restore callee-saved registers and switch to the incoming |
| * thread's stack |
| */ |
| ldw r16, __tTCS_coopReg_OFFSET + __t_coop_r16_OFFSET(r11) |
| ldw r17, __tTCS_coopReg_OFFSET + __t_coop_r17_OFFSET(r11) |
| ldw r18, __tTCS_coopReg_OFFSET + __t_coop_r18_OFFSET(r11) |
| ldw r19, __tTCS_coopReg_OFFSET + __t_coop_r19_OFFSET(r11) |
| ldw r20, __tTCS_coopReg_OFFSET + __t_coop_r20_OFFSET(r11) |
| ldw r21, __tTCS_coopReg_OFFSET + __t_coop_r21_OFFSET(r11) |
| ldw r22, __tTCS_coopReg_OFFSET + __t_coop_r22_OFFSET(r11) |
| ldw r23, __tTCS_coopReg_OFFSET + __t_coop_r23_OFFSET(r11) |
| ldw r28, __tTCS_coopReg_OFFSET + __t_coop_r28_OFFSET(r11) |
| ldw ra, __tTCS_coopReg_OFFSET + __t_coop_ra_OFFSET(r11) |
| ldw sp, __tTCS_coopReg_OFFSET + __t_coop_sp_OFFSET(r11) |
| |
| /* Load return value into r2 (return value register). garbage |
| * unless someone previously called fiberRtnValueSet(). Do this |
| * before we potentially unlock interrupts. |
| */ |
| ldw r2, __tTCS_coopReg_OFFSET + __t_coop_retval_OFFSET(r11) |
| |
| /* irq_unlock(fiber->coopReg.key); |
| * key was supplied as argument to _Swap() |
| */ |
| ldw r3, __tTCS_coopReg_OFFSET + __t_coop_key_OFFSET(r11) |
| #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 |
| |
| BRANCH_LABEL(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 |
| |
