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target/arm/arm-powerctl: Add new arm_set_cpu_on_and_reset()

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Currently the Arm arm-powerctl.h APIs allow:
 * arm_set_cpu_on(), which powers on a CPU and sets its
   initial PC and other startup state
 * arm_reset_cpu(), which resets a CPU which is already on
   (and fails if the CPU is powered off)

but there is no way to say "power on a CPU as if it had
just come out of reset and don't do anything else to it".

Add a new function arm_set_cpu_on_and_reset(), which does this.

Signed-off-by: Peter Maydell <peter.maydell@linaro.org>
Reviewed-by: Richard Henderson <richard.henderson@linaro.org>
Message-id: 20190219125808.25174-5-peter.maydell@linaro.org
This commit is contained in:
Peter Maydell 2019-02-28 10:55:16 +00:00
parent f9f62e4c37
commit ea824b9742
2 changed files with 72 additions and 0 deletions
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56
target/arm/arm-powerctl.c
View File

@ -228,6 +228,62 @@ int arm_set_cpu_on(uint64_t cpuid, uint64_t entry, uint64_t context_id,
return QEMU_ARM_POWERCTL_RET_SUCCESS;
}
static void arm_set_cpu_on_and_reset_async_work(CPUState *target_cpu_state,
run_on_cpu_data data)
{
ARMCPU *target_cpu = ARM_CPU(target_cpu_state);
/* Initialize the cpu we are turning on */
cpu_reset(target_cpu_state);
target_cpu_state->halted = 0;
/* Finally set the power status */
assert(qemu_mutex_iothread_locked());
target_cpu->power_state = PSCI_ON;
}
int arm_set_cpu_on_and_reset(uint64_t cpuid)
{
CPUState *target_cpu_state;
ARMCPU *target_cpu;
assert(qemu_mutex_iothread_locked());
/* 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->power_state == PSCI_ON) {
qemu_log_mask(LOG_GUEST_ERROR,
"[ARM]%s: CPU %" PRId64 " is already on\n",
__func__, cpuid);
return QEMU_ARM_POWERCTL_ALREADY_ON;
}
/*
* If another CPU has powered the target on we are in the state
* ON_PENDING and additional attempts to power on the CPU should
* fail (see 6.6 Implementation CPU_ON/CPU_OFF races in the PSCI
* spec)
*/
if (target_cpu->power_state == PSCI_ON_PENDING) {
qemu_log_mask(LOG_GUEST_ERROR,
"[ARM]%s: CPU %" PRId64 " is already powering on\n",
__func__, cpuid);
return QEMU_ARM_POWERCTL_ON_PENDING;
}
async_run_on_cpu(target_cpu_state, arm_set_cpu_on_and_reset_async_work,
RUN_ON_CPU_NULL);
/* We are good to go */
return QEMU_ARM_POWERCTL_RET_SUCCESS;
}
static void arm_set_cpu_off_async_work(CPUState *target_cpu_state,
run_on_cpu_data data)
{

16
target/arm/arm-powerctl.h
View File

@ -74,4 +74,20 @@ int arm_set_cpu_off(uint64_t cpuid);
*/
int arm_reset_cpu(uint64_t cpuid);
/*
* arm_set_cpu_on_and_reset:
* @cpuid: the id of the CPU we want to star
*
* Start the cpu designated by @cpuid and put it through its normal
* CPU reset process. The CPU will start in the way it is architected
* to start after a power-on reset.
*
* Returns: QEMU_ARM_POWERCTL_RET_SUCCESS on success.
* QEMU_ARM_POWERCTL_INVALID_PARAM if there is no CPU with that ID.
* QEMU_ARM_POWERCTL_ALREADY_ON if the CPU is already on.
* QEMU_ARM_POWERCTL_ON_PENDING if the CPU is already partway through
* powering on.
*/
int arm_set_cpu_on_and_reset(uint64_t cpuid);
#endif