| /* |
| * Copyright (c) 2016 Jean-Paul Etienne <fractalclone@gmail.com> |
| * |
| * SPDX-License-Identifier: Apache-2.0 |
| */ |
| |
| #include <irq.h> |
| #include <kernel_structs.h> |
| #include <offsets_short.h> |
| |
| /* exports */ |
| GTEXT(z_arch_swap) |
| GTEXT(z_thread_entry_wrapper) |
| |
| /* Use ABI name of registers for the sake of simplicity */ |
| |
| /* |
| * unsigned int z_arch_swap(unsigned int key) |
| * |
| * Always called with interrupts locked |
| * key is stored in a0 register |
| */ |
| SECTION_FUNC(exception.other, z_arch_swap) |
| |
| /* Make a system call to perform context switch */ |
| #ifdef CONFIG_EXECUTION_BENCHMARKING |
| addi sp, sp, -__z_arch_esf_t_SIZEOF |
| |
| RV_OP_STOREREG ra, __z_arch_esf_t_ra_OFFSET(sp) |
| RV_OP_STOREREG gp, __z_arch_esf_t_gp_OFFSET(sp) |
| RV_OP_STOREREG tp, __z_arch_esf_t_tp_OFFSET(sp) |
| RV_OP_STOREREG t0, __z_arch_esf_t_t0_OFFSET(sp) |
| RV_OP_STOREREG t1, __z_arch_esf_t_t1_OFFSET(sp) |
| RV_OP_STOREREG t2, __z_arch_esf_t_t2_OFFSET(sp) |
| RV_OP_STOREREG t3, __z_arch_esf_t_t3_OFFSET(sp) |
| RV_OP_STOREREG t4, __z_arch_esf_t_t4_OFFSET(sp) |
| RV_OP_STOREREG t5, __z_arch_esf_t_t5_OFFSET(sp) |
| RV_OP_STOREREG t6, __z_arch_esf_t_t6_OFFSET(sp) |
| RV_OP_STOREREG a0, __z_arch_esf_t_a0_OFFSET(sp) |
| RV_OP_STOREREG a1, __z_arch_esf_t_a1_OFFSET(sp) |
| RV_OP_STOREREG a2, __z_arch_esf_t_a2_OFFSET(sp) |
| RV_OP_STOREREG a3, __z_arch_esf_t_a3_OFFSET(sp) |
| RV_OP_STOREREG a4, __z_arch_esf_t_a4_OFFSET(sp) |
| RV_OP_STOREREG a5, __z_arch_esf_t_a5_OFFSET(sp) |
| RV_OP_STOREREG a6, __z_arch_esf_t_a6_OFFSET(sp) |
| RV_OP_STOREREG a7, __z_arch_esf_t_a7_OFFSET(sp) |
| |
| call read_timer_start_of_swap |
| |
| RV_OP_LOADREG ra, __z_arch_esf_t_ra_OFFSET(sp) |
| RV_OP_LOADREG gp, __z_arch_esf_t_gp_OFFSET(sp) |
| RV_OP_LOADREG tp, __z_arch_esf_t_tp_OFFSET(sp) |
| RV_OP_LOADREG t0, __z_arch_esf_t_t0_OFFSET(sp) |
| RV_OP_LOADREG t1, __z_arch_esf_t_t1_OFFSET(sp) |
| RV_OP_LOADREG t2, __z_arch_esf_t_t2_OFFSET(sp) |
| RV_OP_LOADREG t3, __z_arch_esf_t_t3_OFFSET(sp) |
| RV_OP_LOADREG t4, __z_arch_esf_t_t4_OFFSET(sp) |
| RV_OP_LOADREG t5, __z_arch_esf_t_t5_OFFSET(sp) |
| RV_OP_LOADREG t6, __z_arch_esf_t_t6_OFFSET(sp) |
| RV_OP_LOADREG a0, __z_arch_esf_t_a0_OFFSET(sp) |
| RV_OP_LOADREG a1, __z_arch_esf_t_a1_OFFSET(sp) |
| RV_OP_LOADREG a2, __z_arch_esf_t_a2_OFFSET(sp) |
| RV_OP_LOADREG a3, __z_arch_esf_t_a3_OFFSET(sp) |
| RV_OP_LOADREG a4, __z_arch_esf_t_a4_OFFSET(sp) |
| RV_OP_LOADREG a5, __z_arch_esf_t_a5_OFFSET(sp) |
| RV_OP_LOADREG a6, __z_arch_esf_t_a6_OFFSET(sp) |
| RV_OP_LOADREG a7, __z_arch_esf_t_a7_OFFSET(sp) |
| |
| /* Release stack space */ |
| addi sp, sp, __z_arch_esf_t_SIZEOF |
| #endif |
| ecall |
| |
| /* |
| * when thread is rescheduled, unlock irq and return. |
| * Restored register a0 contains IRQ lock state of thread. |
| * |
| * Prior to unlocking irq, load return value of |
| * z_arch_swap to temp register t2 (from |
| * _thread_offset_to_swap_return_value). Normally, it should be -EAGAIN, |
| * unless someone has previously called z_arch_thread_return_value_set(..). |
| */ |
| la t0, _kernel |
| |
| /* Get pointer to _kernel.current */ |
| RV_OP_LOADREG t1, _kernel_offset_to_current(t0) |
| |
| /* Load return value of z_arch_swap function in temp register t2 */ |
| lw t2, _thread_offset_to_swap_return_value(t1) |
| |
| /* |
| * Unlock irq, following IRQ lock state in a0 register. |
| * Use atomic instruction csrrs to do so. |
| */ |
| andi a0, a0, SOC_MSTATUS_IEN |
| csrrs t0, mstatus, a0 |
| |
| /* Set value of return register a0 to value of register t2 */ |
| addi a0, t2, 0 |
| |
| /* Return */ |
| jalr x0, ra |
| |
| |
| /* |
| * void z_thread_entry_wrapper(k_thread_entry_t, void *, void *, void *) |
| */ |
| SECTION_FUNC(TEXT, z_thread_entry_wrapper) |
| /* |
| * z_thread_entry_wrapper is called for every new thread upon the return |
| * of z_arch_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 z_thread_entry. Hence, just call z_thread_entry with |
| * return address set to 0 to indicate a non-returning function call. |
| */ |
| |
| jal x0, z_thread_entry |
