ARM: Factor out ARM on/off PSCI control functions

Split ARM on/off function from PSCI support code.

This will allow to reuse these functions in other code.

Signed-off-by: Jean-Christophe Dubois <jcd@tribudubois.net>
Reviewed-by: Peter Maydell <peter.maydell@linaro.org>
Signed-off-by: Peter Maydell <peter.maydell@linaro.org>

1 files changed, 224 insertions, 0 deletions

diff --git a/target-arm/arm-powerctl.c b/target-arm/arm-powerctl.c
new file mode 100644
index 0000000000..cb9919b465
--- /dev/null
+++ b/target-arm/arm-powerctl.c
@@ -0,0 +1,224 @@
+/*
+ * QEMU support -- ARM Power Control specific functions.
+ *
+ * Copyright (c) 2016 Jean-Christophe Dubois
+ *
+ * This work is licensed under the terms of the GNU GPL, version 2 or later.
+ * See the COPYING file in the top-level directory.
+ *
+ */
+
+#include "qemu/osdep.h"
+#include <cpu.h>
+#include <cpu-qom.h>
+#include "internals.h"
+#include "arm-powerctl.h"
+
+#ifndef DEBUG_ARM_POWERCTL
+#define DEBUG_ARM_POWERCTL 0
+#endif
+
+#define DPRINTF(fmt, args...) \
+    do { \
+        if (DEBUG_ARM_POWERCTL) { \
+            fprintf(stderr, "[ARM]%s: " fmt , __func__, ##args); \
+        } \
+    } while (0)
+
+CPUState *arm_get_cpu_by_id(uint64_t id)
+{
+    CPUState *cpu;
+
+    DPRINTF("cpu %" PRId64 "\n", id);
+
+    CPU_FOREACH(cpu) {
+        ARMCPU *armcpu = ARM_CPU(cpu);
+
+        if (armcpu->mp_affinity == id) {
+            return cpu;
+        }
+    }
+
+    qemu_log_mask(LOG_GUEST_ERROR,
+                  "[ARM]%s: Requesting unknown CPU %" PRId64 "\n",
+                  __func__, id);
+
+    return NULL;
+}
+
+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;
+}
+
+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;
+}