f4d1414a93
The OpenRISC architecture has the Power Management Register (PMR) special purpose register to manage cpu power states. The interesting modes are: * Doze Mode (DME) - Stop cpu except timer & pic - wake on interrupt * Sleep Mode (SME) - Stop cpu and all units - wake on interrupt * Suspend Model (SUME) - Stop cpu and all units - wake on reset The linux kernel will set DME when idle. This patch implements the PMR SPR and halts the qemu cpu when there is a change to DME or SME. This means that openrisc qemu in no longer peggs a host cpu at 100%. In order for this to work we need to kick the CPU when timers are expired. Update the cpu timer to kick the cpu upon each timer event. Reviewed-by: Richard Henderson <rth@twiddle.net> Signed-off-by: Stafford Horne <shorne@gmail.com>
105 lines
3.0 KiB
C
105 lines
3.0 KiB
C
/*
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* OpenRISC interrupt.
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*
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* Copyright (c) 2011-2012 Jia Liu <proljc@gmail.com>
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*
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* This library is free software; you can redistribute it and/or
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* modify it under the terms of the GNU Lesser General Public
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* License as published by the Free Software Foundation; either
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* version 2 of the License, or (at your option) any later version.
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*
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* This library is distributed in the hope that it will be useful,
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* but WITHOUT ANY WARRANTY; without even the implied warranty of
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* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
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* Lesser General Public License for more details.
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*
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* You should have received a copy of the GNU Lesser General Public
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* License along with this library; if not, see <http://www.gnu.org/licenses/>.
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*/
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#include "qemu/osdep.h"
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#include "cpu.h"
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#include "exec/exec-all.h"
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#include "qemu-common.h"
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#include "exec/gdbstub.h"
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#include "qemu/host-utils.h"
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#ifndef CONFIG_USER_ONLY
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#include "hw/loader.h"
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#endif
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void openrisc_cpu_do_interrupt(CPUState *cs)
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{
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#ifndef CONFIG_USER_ONLY
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OpenRISCCPU *cpu = OPENRISC_CPU(cs);
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CPUOpenRISCState *env = &cpu->env;
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env->epcr = env->pc;
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if (env->dflag) {
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env->dflag = 0;
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env->sr |= SR_DSX;
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env->epcr -= 4;
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} else {
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env->sr &= ~SR_DSX;
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}
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if (cs->exception_index == EXCP_SYSCALL) {
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env->epcr += 4;
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}
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/* When we have an illegal instruction the error effective address
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shall be set to the illegal instruction address. */
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if (cs->exception_index == EXCP_ILLEGAL) {
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env->eear = env->pc;
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}
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/* For machine-state changed between user-mode and supervisor mode,
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we need flush TLB when we enter&exit EXCP. */
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tlb_flush(cs);
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env->esr = cpu_get_sr(env);
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env->sr &= ~SR_DME;
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env->sr &= ~SR_IME;
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env->sr |= SR_SM;
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env->sr &= ~SR_IEE;
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env->sr &= ~SR_TEE;
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env->pmr &= ~PMR_DME;
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env->pmr &= ~PMR_SME;
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env->tlb->cpu_openrisc_map_address_data = &cpu_openrisc_get_phys_nommu;
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env->tlb->cpu_openrisc_map_address_code = &cpu_openrisc_get_phys_nommu;
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env->lock_addr = -1;
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if (cs->exception_index > 0 && cs->exception_index < EXCP_NR) {
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hwaddr vect_pc = cs->exception_index << 8;
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if (env->cpucfgr & CPUCFGR_EVBARP) {
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vect_pc |= env->evbar;
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}
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if (env->sr & SR_EPH) {
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vect_pc |= 0xf0000000;
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}
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env->pc = vect_pc;
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} else {
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cpu_abort(cs, "Unhandled exception 0x%x\n", cs->exception_index);
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}
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#endif
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cs->exception_index = -1;
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}
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bool openrisc_cpu_exec_interrupt(CPUState *cs, int interrupt_request)
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{
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OpenRISCCPU *cpu = OPENRISC_CPU(cs);
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CPUOpenRISCState *env = &cpu->env;
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int idx = -1;
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if ((interrupt_request & CPU_INTERRUPT_HARD) && (env->sr & SR_IEE)) {
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idx = EXCP_INT;
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}
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if ((interrupt_request & CPU_INTERRUPT_TIMER) && (env->sr & SR_TEE)) {
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idx = EXCP_TICK;
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}
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if (idx >= 0) {
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cs->exception_index = idx;
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openrisc_cpu_do_interrupt(cs);
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return true;
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}
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return false;
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}
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