diff options
Diffstat (limited to 'target-arm/psci.c')
| -rw-r--r-- | target-arm/psci.c | 242 |
1 files changed, 242 insertions, 0 deletions
diff --git a/target-arm/psci.c b/target-arm/psci.c new file mode 100644 index 0000000..d8fafab --- /dev/null +++ b/target-arm/psci.c @@ -0,0 +1,242 @@ +/* + * 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 */ +} |