diff options
Diffstat (limited to 'arch')
| -rw-r--r-- | arch/riscv64/kernel/entry.S | 43 |
1 files changed, 10 insertions, 33 deletions
diff --git a/arch/riscv64/kernel/entry.S b/arch/riscv64/kernel/entry.S index f099065..b4308b4 100644 --- a/arch/riscv64/kernel/entry.S +++ b/arch/riscv64/kernel/entry.S @@ -72,39 +72,21 @@ _save_context: /* interrupts fall through, exceptions jump */ bge s4, zero, handle_exception /* TODO: handle interrupts */ - j restore_all + j _load_context handle_exception: li t0, EXC_SYSCALL /* system exceptions fall through, syscalls and ipis jump */ /* temp, at some point we want to handle system exceptions as well */ beq s4, t0, handle_dispatch - j restore_all + j _load_context handle_dispatch: /* store execution continuation point */ csrr s0, CSR_SEPC sr s0, offsetof_exec(tp) - /* allocate space for sys_ret structure on stack and shift argument - * registers down one to make room for the pointer to this structure */ - addi sp, sp, -sizeof_sys_ret - mv a6, a5 - mv a5, a4 - mv a4, a3 - mv a3, a2 - mv a2, a1 - mv a1, a0 - mv a0, sp /* jump to C */ jal dispatch - /* move structure from stack into registers. */ - lr a0, offsetof_s(sp) - lr a1, offsetof_ar0(sp) - lr a2, offsetof_ar1(sp) - lr a3, offsetof_ar2(sp) - lr a4, offsetof_ar3(sp) - lr a5, offsetof_ar4(sp) - addi sp, sp, sizeof_sys_ret /* if we had a thread switch, load kernel stack of current thread and * restore its context */ /* get associated kernel stack */ @@ -113,18 +95,8 @@ handle_dispatch: /* set execution continuation */ lr s0, offsetof_exec(tp) csrw CSR_SEPC, s0 - /* restore system call result */ - j restore_noreturn -restore_all: - lr a0, offsetof_a0(sp) - lr a1, offsetof_a1(sp) - lr a2, offsetof_a2(sp) - lr a3, offsetof_a3(sp) - lr a4, offsetof_a4(sp) - lr a5, offsetof_a5(sp) - -restore_noreturn: +_load_context: /* restore registers besides possible return value, assume instruction * to return to has already been set (CSR_EPC) */ csrw CSR_SSCRATCH, tp @@ -135,8 +107,14 @@ restore_noreturn: lr t0, offsetof_t0(sp) lr t1, offsetof_t1(sp) lr t2, offsetof_t2(sp) - /* a0 - a5 should not be restored when coming from a syscall */ + lr a0, offsetof_a0(sp) + lr a1, offsetof_a1(sp) + lr a2, offsetof_a2(sp) + lr a3, offsetof_a3(sp) + lr a4, offsetof_a4(sp) + lr a5, offsetof_a5(sp) lr a6, offsetof_a6(sp) + lr a7, offsetof_a7(sp) lr s0, offsetof_s0(sp) lr s1, offsetof_s1(sp) lr s2, offsetof_s2(sp) @@ -149,7 +127,6 @@ restore_noreturn: lr s9, offsetof_s9(sp) lr s10,offsetof_s10(sp) lr s11,offsetof_s11(sp) - lr a7, offsetof_a7(sp) lr t3, offsetof_t3(sp) lr t4, offsetof_t4(sp) lr t5, offsetof_t5(sp) |