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/*
* Copyright (C) 2014 - Linaro
* Author: Rob Herring <rob.herring@linaro.org>
*
* This program is free software; you can redistribute it and/or modify
* it under the terms of the GNU General Public License as published by
* the Free Software Foundation; either version 2 of the License, or
* (at your option) any later version.
*
* This program is distributed in the hope that it will be useful,
* but WITHOUT ANY WARRANTY; without even the implied warranty of
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
* GNU General Public License for more details.
*
* You should have received a copy of the GNU General Public License
* along with this program; if not, see <http://www.gnu.org/licenses/>.
*/
#include <cpu.h>
#include <cpu-qom.h>
#include <exec/helper-proto.h>
#include <kvm-consts.h>
#include <sysemu/sysemu.h>
#include "internals.h"
bool arm_is_psci_call(ARMCPU *cpu, int excp_type)
{
/* Return true if the r0/x0 value indicates a PSCI call and
* the exception type matches the configured PSCI conduit. This is
* called before the SMC/HVC instruction is executed, to decide whether
* we should treat it as a PSCI call or with the architecturally
* defined behaviour for an SMC or HVC (which might be UNDEF or trap
* to EL2 or to EL3).
*/
CPUARMState *env = &cpu->env;
uint64_t param = is_a64(env) ? env->xregs[0] : env->regs[0];
switch (excp_type) {
case EXCP_HVC:
if (cpu->psci_conduit != QEMU_PSCI_CONDUIT_HVC) {
return false;
}
break;
case EXCP_SMC:
if (cpu->psci_conduit != QEMU_PSCI_CONDUIT_SMC) {
return false;
}
break;
default:
return false;
}
switch (param) {
case QEMU_PSCI_0_2_FN_PSCI_VERSION:
case QEMU_PSCI_0_2_FN_MIGRATE_INFO_TYPE:
case QEMU_PSCI_0_2_FN_AFFINITY_INFO:
case QEMU_PSCI_0_2_FN64_AFFINITY_INFO:
case QEMU_PSCI_0_2_FN_SYSTEM_RESET:
case QEMU_PSCI_0_2_FN_SYSTEM_OFF:
case QEMU_PSCI_0_1_FN_CPU_ON:
case QEMU_PSCI_0_2_FN_CPU_ON:
case QEMU_PSCI_0_2_FN64_CPU_ON:
case QEMU_PSCI_0_1_FN_CPU_OFF:
case QEMU_PSCI_0_2_FN_CPU_OFF:
case QEMU_PSCI_0_1_FN_CPU_SUSPEND:
case QEMU_PSCI_0_2_FN_CPU_SUSPEND:
case QEMU_PSCI_0_2_FN64_CPU_SUSPEND:
case QEMU_PSCI_0_1_FN_MIGRATE:
case QEMU_PSCI_0_2_FN_MIGRATE:
return true;
default:
return false;
}
}
void arm_handle_psci_call(ARMCPU *cpu)
{
/*
* This function partially implements the logic for dispatching Power State
* Coordination Interface (PSCI) calls (as described in ARM DEN 0022B.b),
* to the extent required for bringing up and taking down secondary cores,
* and for handling reset and poweroff requests.
* Additional information about the calling convention used is available in
* the document 'SMC Calling Convention' (ARM DEN 0028)
*/
CPUState *cs = CPU(cpu);
CPUARMState *env = &cpu->env;
uint64_t param[4];
uint64_t context_id, mpidr;
target_ulong entry;
int32_t ret = 0;
int i;
for (i = 0; i < 4; i++) {
/*
* All PSCI functions take explicit 32-bit or native int sized
* arguments so we can simply zero-extend all arguments regardless
* of which exact function we are about to call.
*/
param[i] = is_a64(env) ? env->xregs[i] : env->regs[i];
}
if ((param[0] & QEMU_PSCI_0_2_64BIT) && !is_a64(env)) {
ret = QEMU_PSCI_RET_INVALID_PARAMS;
goto err;
}
switch (param[0]) {
CPUState *target_cpu_state;
ARMCPU *target_cpu;
CPUClass *target_cpu_class;
case QEMU_PSCI_0_2_FN_PSCI_VERSION:
ret = QEMU_PSCI_0_2_RET_VERSION_0_2;
break;
case QEMU_PSCI_0_2_FN_MIGRATE_INFO_TYPE:
ret = QEMU_PSCI_0_2_RET_TOS_MIGRATION_NOT_REQUIRED; /* No trusted OS */
break;
case QEMU_PSCI_0_2_FN_AFFINITY_INFO:
case QEMU_PSCI_0_2_FN64_AFFINITY_INFO:
mpidr = param[1];
switch (param[2]) {
case 0:
target_cpu_state = qemu_get_cpu(mpidr & 0xff);
if (!target_cpu_state) {
ret = QEMU_PSCI_RET_INVALID_PARAMS;
break;
}
target_cpu = ARM_CPU(target_cpu_state);
ret = target_cpu->powered_off ? 1 : 0;
break;
default:
/* Everything above affinity level 0 is always on. */
ret = 0;
}
break;
case QEMU_PSCI_0_2_FN_SYSTEM_RESET:
qemu_system_reset_request();
/* QEMU reset and shutdown are async requests, but PSCI
* mandates that we never return from the reset/shutdown
* call, so power the CPU off now so it doesn't execute
* anything further.
*/
goto cpu_off;
case QEMU_PSCI_0_2_FN_SYSTEM_OFF:
qemu_system_shutdown_request();
goto cpu_off;
case QEMU_PSCI_0_1_FN_CPU_ON:
case QEMU_PSCI_0_2_FN_CPU_ON:
case QEMU_PSCI_0_2_FN64_CPU_ON:
mpidr = param[1];
entry = param[2];
context_id = param[3];
/* change to the cpu we are powering up */
target_cpu_state = qemu_get_cpu(mpidr & 0xff);
if (!target_cpu_state) {
ret = QEMU_PSCI_RET_INVALID_PARAMS;
break;
}
target_cpu = ARM_CPU(target_cpu_state);
if (!target_cpu->powered_off) {
ret = QEMU_PSCI_RET_ALREADY_ON;
break;
}
target_cpu_class = CPU_GET_CLASS(target_cpu);
/* Initialize the cpu we are turning on */
cpu_reset(target_cpu_state);
target_cpu->powered_off = false;
target_cpu_state->halted = 0;
/*
* The PSCI spec mandates that newly brought up CPUs enter the
* exception level of the caller in the same execution mode as
* the caller, with context_id in x0/r0, respectively.
*
* For now, it is sufficient to assert() that CPUs come out of
* reset in the same mode as the calling CPU, since we only
* implement EL1, which means that
* (a) there is no EL2 for the calling CPU to trap into to change
* its state
* (b) the newly brought up CPU enters EL1 immediately after coming
* out of reset in the default state
*/
assert(is_a64(env) == is_a64(&target_cpu->env));
if (is_a64(env)) {
if (entry & 1) {
ret = QEMU_PSCI_RET_INVALID_PARAMS;
break;
}
target_cpu->env.xregs[0] = context_id;
} else {
target_cpu->env.regs[0] = context_id;
target_cpu->env.thumb = entry & 1;
}
target_cpu_class->set_pc(target_cpu_state, entry);
ret = 0;
break;
case QEMU_PSCI_0_1_FN_CPU_OFF:
case QEMU_PSCI_0_2_FN_CPU_OFF:
goto cpu_off;
case QEMU_PSCI_0_1_FN_CPU_SUSPEND:
case QEMU_PSCI_0_2_FN_CPU_SUSPEND:
case QEMU_PSCI_0_2_FN64_CPU_SUSPEND:
/* Affinity levels are not supported in QEMU */
if (param[1] & 0xfffe0000) {
ret = QEMU_PSCI_RET_INVALID_PARAMS;
break;
}
/* Powerdown is not supported, we always go into WFI */
if (is_a64(env)) {
env->xregs[0] = 0;
} else {
env->regs[0] = 0;
}
helper_wfi(env);
break;
case QEMU_PSCI_0_1_FN_MIGRATE:
case QEMU_PSCI_0_2_FN_MIGRATE:
ret = QEMU_PSCI_RET_NOT_SUPPORTED;
break;
default:
g_assert_not_reached();
}
err:
if (is_a64(env)) {
env->xregs[0] = ret;
} else {
env->regs[0] = ret;
}
return;
cpu_off:
cpu->powered_off = true;
cs->halted = 1;
cs->exception_index = EXCP_HLT;
cpu_loop_exit(cs);
/* notreached */
}
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