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-rw-r--r--qemu/target-arm/psci.c257
1 files changed, 257 insertions, 0 deletions
diff --git a/qemu/target-arm/psci.c b/qemu/target-arm/psci.c
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+++ b/qemu/target-arm/psci.c
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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;
+ }
+}
+
+static CPUState *get_cpu_by_id(uint64_t id)
+{
+ CPUState *cpu;
+
+ CPU_FOREACH(cpu) {
+ ARMCPU *armcpu = ARM_CPU(cpu);
+
+ if (armcpu->mp_affinity == id) {
+ return cpu;
+ }
+ }
+
+ return NULL;
+}
+
+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 = get_cpu_by_id(mpidr);
+ 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 = get_cpu_by_id(mpidr);
+ 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 */
+}