int arm_set_cpu_off(uint64_t cpuid)
{
CPUState *target_cpu_state;
ARMCPU *target_cpu;
DPRINTF("cpu %" PRId64 "\n", cpuid);
/* change to the cpu we are powering up */
target_cpu_state = arm_get_cpu_by_id(cpuid);
if (!target_cpu_state) {
return QEMU_ARM_POWERCTL_INVALID_PARAM;
}
target_cpu = ARM_CPU(target_cpu_state);
if (target_cpu->powered_off) {
qemu_log_mask(LOG_GUEST_ERROR,
"[ARM]%s: CPU %" PRId64 " is already off\n",
__func__, cpuid);
return QEMU_ARM_POWERCTL_IS_OFF;
}
target_cpu->powered_off = true;
target_cpu_state->halted = 1;
target_cpu_state->exception_index = EXCP_HLT;
cpu_loop_exit(target_cpu_state);
/* notreached */
return QEMU_ARM_POWERCTL_RET_SUCCESS;
}
int arm_reset_cpu(uint64_t cpuid)
{
CPUState *target_cpu_state;
ARMCPU *target_cpu;
DPRINTF("cpu %" PRId64 "\n", cpuid);
/* change to the cpu we are resetting */
target_cpu_state = arm_get_cpu_by_id(cpuid);
if (!target_cpu_state) {
return QEMU_ARM_POWERCTL_INVALID_PARAM;
}
target_cpu = ARM_CPU(target_cpu_state);
if (target_cpu->powered_off) {
qemu_log_mask(LOG_GUEST_ERROR,
"[ARM]%s: CPU %" PRId64 " is off\n",
__func__, cpuid);
return QEMU_ARM_POWERCTL_IS_OFF;
}
/* Reset the cpu */
cpu_reset(target_cpu_state);
return QEMU_ARM_POWERCTL_RET_SUCCESS;
}
int arm_set_cpu_on(uint64_t cpuid, uint64_t entry, uint64_t context_id,
uint32_t target_el, bool target_aa64)
{
CPUState *target_cpu_state;
ARMCPU *target_cpu;
DPRINTF("cpu %" PRId64 " (EL %d, %s) @ 0x%" PRIx64 " with R0 = 0x%" PRIx64
"\n", cpuid, target_el, target_aa64 ? "aarch64" : "aarch32", entry,
context_id);
/* requested EL level need to be in the 1 to 3 range */
assert((target_el > 0) && (target_el < 4));
if (target_aa64 && (entry & 3)) {
/*
* if we are booting in AArch64 mode then "entry" needs to be 4 bytes
* aligned.
*/
return QEMU_ARM_POWERCTL_INVALID_PARAM;
}
/* Retrieve the cpu we are powering up */
target_cpu_state = arm_get_cpu_by_id(cpuid);
if (!target_cpu_state) {
/* The cpu was not found */
return QEMU_ARM_POWERCTL_INVALID_PARAM;
}
target_cpu = ARM_CPU(target_cpu_state);
if (!target_cpu->powered_off) {
qemu_log_mask(LOG_GUEST_ERROR,
"[ARM]%s: CPU %" PRId64 " is already on\n",
__func__, cpuid);
return QEMU_ARM_POWERCTL_ALREADY_ON;
}
/*
* The newly brought CPU is requested to enter the exception level
* "target_el" and be in the requested mode (AArch64 or AArch32).
*/
if (((target_el == 3) && !arm_feature(&target_cpu->env, ARM_FEATURE_EL3)) ||
((target_el == 2) && !arm_feature(&target_cpu->env, ARM_FEATURE_EL2))) {
/*
* The CPU does not support requested level
*/
return QEMU_ARM_POWERCTL_INVALID_PARAM;
}
if (!target_aa64 && arm_feature(&target_cpu->env, ARM_FEATURE_AARCH64)) {
/*
* For now we don't support booting an AArch64 CPU in AArch32 mode
* TODO: We should add this support later
*/
qemu_log_mask(LOG_UNIMP,
"[ARM]%s: Starting AArch64 CPU %" PRId64
" in AArch32 mode is not supported yet\n",
__func__, cpuid);
return QEMU_ARM_POWERCTL_INVALID_PARAM;
}
/* Initialize the cpu we are turning on */
cpu_reset(target_cpu_state);
target_cpu->powered_off = false;
target_cpu_state->halted = 0;
if (target_aa64) {
if ((target_el < 3) && arm_feature(&target_cpu->env, ARM_FEATURE_EL3)) {
/*
* As target mode is AArch64, we need to set lower
* exception level (the requested level 2) to AArch64
*/
target_cpu->env.cp15.scr_el3 |= SCR_RW;
}
if ((target_el < 2) && arm_feature(&target_cpu->env, ARM_FEATURE_EL2)) {
/*
* As target mode is AArch64, we need to set lower
* exception level (the requested level 1) to AArch64
*/
target_cpu->env.cp15.hcr_el2 |= HCR_RW;
}
target_cpu->env.pstate = aarch64_pstate_mode(target_el, true);
} else {
/* We are requested to boot in AArch32 mode */
static uint32_t mode_for_el[] = { 0,
ARM_CPU_MODE_SVC,
ARM_CPU_MODE_HYP,
ARM_CPU_MODE_SVC };
cpsr_write(&target_cpu->env, mode_for_el[target_el], CPSR_M,
CPSRWriteRaw);
}
if (target_el == 3) {
/* Processor is in secure mode */
target_cpu->env.cp15.scr_el3 &= ~SCR_NS;
} else {
/* Processor is not in secure mode */
target_cpu->env.cp15.scr_el3 |= SCR_NS;
}
/* We check if the started CPU is now at the correct level */
assert(target_el == arm_current_el(&target_cpu->env));
if (target_aa64) {
target_cpu->env.xregs[0] = context_id;
target_cpu->env.thumb = false;
} else {
target_cpu->env.regs[0] = context_id;
target_cpu->env.thumb = entry & 1;
entry &= 0xfffffffe;
}
/* Start the new CPU at the requested address */
cpu_set_pc(target_cpu_state, entry);
/* We are good to go */
return QEMU_ARM_POWERCTL_RET_SUCCESS;
}
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)
*/
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;
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 = arm_get_cpu_by_id(mpidr);
if (!target_cpu_state) {
ret = QEMU_PSCI_RET_INVALID_PARAMS;
break;
}
target_cpu = ARM_CPU(target_cpu_state);
g_assert(qemu_mutex_iothread_locked());
ret = target_cpu->power_state;
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(SHUTDOWN_CAUSE_GUEST_RESET);
/* 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(SHUTDOWN_CAUSE_GUEST_SHUTDOWN);
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:
{
/* The PSCI spec mandates that newly brought up CPUs start
* in the highest exception level which exists and is enabled
* on the calling CPU. Since the QEMU PSCI implementation is
* acting as a "fake EL3" or "fake EL2" firmware, this for us
* means that we want to start at the highest NS exception level
* that we are providing to the guest.
* The execution mode should be that which is currently in use
* by the same exception level on the calling CPU.
* The CPU should be started with the context_id value
* in x0 (if AArch64) or r0 (if AArch32).
*/
int target_el = arm_feature(env, ARM_FEATURE_EL2) ? 2 : 1;
bool target_aarch64 = arm_el_is_aa64(env, target_el);
mpidr = param[1];
entry = param[2];
context_id = param[3];
ret = arm_set_cpu_on(mpidr, entry, context_id,
target_el, target_aarch64);
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, 4);
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:
ret = arm_set_cpu_off(cpu->mp_affinity);
/* notreached */
/* sanity check in case something failed */
assert(ret == QEMU_ARM_POWERCTL_RET_SUCCESS);
}
