diff options
Diffstat (limited to 'sys/mips/mips/swtch.S')
| -rw-r--r-- | sys/mips/mips/swtch.S | 27 |
1 files changed, 10 insertions, 17 deletions
diff --git a/sys/mips/mips/swtch.S b/sys/mips/mips/swtch.S index 8620ab4..1248276 100644 --- a/sys/mips/mips/swtch.S +++ b/sys/mips/mips/swtch.S @@ -161,21 +161,19 @@ LEAF(fork_trampoline) DO_AST -/* - * Since interrupts are enabled at this point, we use a1 instead of - * k0 or k1 to store the PCB pointer. This is because k0 and k1 - * are not preserved across interrupts. - */ - GET_CPU_PCPU(a1) - lw a1, PC_CURPCB(a1) -1: - - mfc0 v0, COP_0_STATUS_REG # set exeption level bit. + mfc0 v0, COP_0_STATUS_REG and v0, ~(SR_INT_ENAB) - mtc0 v0, COP_0_STATUS_REG # set exeption level bit. + mtc0 v0, COP_0_STATUS_REG # disable interrupts COP0_SYNC +/* + * The use of k1 for storing the PCB pointer must be done only + * after interrupts are disabled. Otherwise it will get overwritten + * by the interrupt code. + */ .set noat - move k1, a1 + GET_CPU_PCPU(k1) + lw k1, PC_CURPCB(k1) + RESTORE_U_PCB_REG(t0, MULLO, k1) RESTORE_U_PCB_REG(t1, MULHI, k1) mtlo t0 @@ -185,11 +183,6 @@ LEAF(fork_trampoline) RESTORE_U_PCB_REG(v0, V0, k1) _MTC0 a0, COP_0_EXC_PC # set return address -/* - * The use of k1 for storing the PCB pointer must be done only - * after interrupts are disabled. Otherwise it will get overwritten - * by the interrupt code. - */ RESTORE_U_PCB_REG(v1, V1, k1) RESTORE_U_PCB_REG(a0, A0, k1) RESTORE_U_PCB_REG(a1, A1, k1) |
