target/arm/arm-powerctl.c

   1 /*
   2  * QEMU support -- ARM Power Control specific functions.
   3  *
   4  * Copyright (c) 2016 Jean-Christophe Dubois
   5  *
   6  * This work is licensed under the terms of the GNU GPL, version 2 or later.
   7  * See the COPYING file in the top-level directory.
   8  *
   9  */
  10
  11 #include "qemu/osdep.h"
  12 #include "cpu.h"
  13 #include "cpu-qom.h"
  14 #include "internals.h"
  15 #include "arm-powerctl.h"
  16 #include "qemu/log.h"
  17 #include "exec/exec-all.h"
  18
  19 #ifndef DEBUG_ARM_POWERCTL
  20 #define DEBUG_ARM_POWERCTL 0
  21 #endif
  22
  23 #define DPRINTF(fmt, args...) \
  24     do { \
  25         if (DEBUG_ARM_POWERCTL) { \
  26             fprintf(stderr, "[ARM]%s: " fmt , __func__, ##args); \
  27         } \
  28     } while (0)
  29
  30 CPUState *arm_get_cpu_by_id(uint64_t id)
  31 {
  32     CPUState *cpu;
  33
  34     DPRINTF("cpu %" PRId64 "\n", id);
  35
  36     CPU_FOREACH(cpu) {
  37         ARMCPU *armcpu = ARM_CPU(cpu);
  38
  39         if (armcpu->mp_affinity == id) {
  40             return cpu;
  41         }
  42     }
  43
  44     qemu_log_mask(LOG_GUEST_ERROR,
  45                   "[ARM]%s: Requesting unknown CPU %" PRId64 "\n",
  46                   __func__, id);
  47
  48     return NULL;
  49 }
  50
  51 int arm_set_cpu_on(uint64_t cpuid, uint64_t entry, uint64_t context_id,
  52                    uint32_t target_el, bool target_aa64)
  53 {
  54     CPUState *target_cpu_state;
  55     ARMCPU *target_cpu;
  56
  57     DPRINTF("cpu %" PRId64 " (EL %d, %s) @ 0x%" PRIx64 " with R0 = 0x%" PRIx64
  58             "\n", cpuid, target_el, target_aa64 ? "aarch64" : "aarch32", entry,
  59             context_id);
  60
  61     /* requested EL level need to be in the 1 to 3 range */
  62     assert((target_el > 0) && (target_el < 4));
  63
  64     if (target_aa64 && (entry & 3)) {
  65         /*
  66          * if we are booting in AArch64 mode then "entry" needs to be 4 bytes
  67          * aligned.
  68          */
  69         return QEMU_ARM_POWERCTL_INVALID_PARAM;
  70     }
  71
  72     /* Retrieve the cpu we are powering up */
  73     target_cpu_state = arm_get_cpu_by_id(cpuid);
  74     if (!target_cpu_state) {
  75         /* The cpu was not found */
  76         return QEMU_ARM_POWERCTL_INVALID_PARAM;
  77     }
  78
  79     target_cpu = ARM_CPU(target_cpu_state);
  80     if (!target_cpu->powered_off) {
  81         qemu_log_mask(LOG_GUEST_ERROR,
  82                       "[ARM]%s: CPU %" PRId64 " is already on\n",
  83                       __func__, cpuid);
  84         return QEMU_ARM_POWERCTL_ALREADY_ON;
  85     }
  86
  87     /*
  88      * The newly brought CPU is requested to enter the exception level
  89      * "target_el" and be in the requested mode (AArch64 or AArch32).
  90      */
  91
  92     if (((target_el == 3) && !arm_feature(&target_cpu->env, ARM_FEATURE_EL3)) ||
  93         ((target_el == 2) && !arm_feature(&target_cpu->env, ARM_FEATURE_EL2))) {
  94         /*
  95          * The CPU does not support requested level
  96          */
  97         return QEMU_ARM_POWERCTL_INVALID_PARAM;
  98     }
  99
 100     if (!target_aa64 && arm_feature(&target_cpu->env, ARM_FEATURE_AARCH64)) {
 101         /*
 102          * For now we don't support booting an AArch64 CPU in AArch32 mode
 103          * TODO: We should add this support later
 104          */
 105         qemu_log_mask(LOG_UNIMP,
 106                       "[ARM]%s: Starting AArch64 CPU %" PRId64
 107                       " in AArch32 mode is not supported yet\n",
 108                       __func__, cpuid);
 109         return QEMU_ARM_POWERCTL_INVALID_PARAM;
 110     }
 111
 112     /* Initialize the cpu we are turning on */
 113     cpu_reset(target_cpu_state);
 114     target_cpu->powered_off = false;
 115     target_cpu_state->halted = 0;
 116
 117     if (target_aa64) {
 118         if ((target_el < 3) && arm_feature(&target_cpu->env, ARM_FEATURE_EL3)) {
 119             /*
 120              * As target mode is AArch64, we need to set lower
 121              * exception level (the requested level 2) to AArch64
 122              */
 123             target_cpu->env.cp15.scr_el3 |= SCR_RW;
 124         }
 125
 126         if ((target_el < 2) && arm_feature(&target_cpu->env, ARM_FEATURE_EL2)) {
 127             /*
 128              * As target mode is AArch64, we need to set lower
 129              * exception level (the requested level 1) to AArch64
 130              */
 131             target_cpu->env.cp15.hcr_el2 |= HCR_RW;
 132         }
 133
 134         target_cpu->env.pstate = aarch64_pstate_mode(target_el, true);
 135     } else {
 136         /* We are requested to boot in AArch32 mode */
 137         static uint32_t mode_for_el[] = { 0,
 138                                           ARM_CPU_MODE_SVC,
 139                                           ARM_CPU_MODE_HYP,
 140                                           ARM_CPU_MODE_SVC };
 141
 142         cpsr_write(&target_cpu->env, mode_for_el[target_el], CPSR_M,
 143                    CPSRWriteRaw);
 144     }
 145
 146     if (target_el == 3) {
 147         /* Processor is in secure mode */
 148         target_cpu->env.cp15.scr_el3 &= ~SCR_NS;
 149     } else {
 150         /* Processor is not in secure mode */
 151         target_cpu->env.cp15.scr_el3 |= SCR_NS;
 152     }
 153
 154     /* We check if the started CPU is now at the correct level */
 155     assert(target_el == arm_current_el(&target_cpu->env));
 156
 157     if (target_aa64) {
 158         target_cpu->env.xregs[0] = context_id;
 159         target_cpu->env.thumb = false;
 160     } else {
 161         target_cpu->env.regs[0] = context_id;
 162         target_cpu->env.thumb = entry & 1;
 163         entry &= 0xfffffffe;
 164     }
 165
 166     /* Start the new CPU at the requested address */
 167     cpu_set_pc(target_cpu_state, entry);
 168
 169     qemu_cpu_kick(target_cpu_state);
 170
 171     /* We are good to go */
 172     return QEMU_ARM_POWERCTL_RET_SUCCESS;
 173 }
 174
 175 int arm_set_cpu_off(uint64_t cpuid)
 176 {
 177     CPUState *target_cpu_state;
 178     ARMCPU *target_cpu;
 179
 180     DPRINTF("cpu %" PRId64 "\n", cpuid);
 181
 182     /* change to the cpu we are powering up */
 183     target_cpu_state = arm_get_cpu_by_id(cpuid);
 184     if (!target_cpu_state) {
 185         return QEMU_ARM_POWERCTL_INVALID_PARAM;
 186     }
 187     target_cpu = ARM_CPU(target_cpu_state);
 188     if (target_cpu->powered_off) {
 189         qemu_log_mask(LOG_GUEST_ERROR,
 190                       "[ARM]%s: CPU %" PRId64 " is already off\n",
 191                       __func__, cpuid);
 192         return QEMU_ARM_POWERCTL_IS_OFF;
 193     }
 194
 195     target_cpu->powered_off = true;
 196     target_cpu_state->halted = 1;
 197     target_cpu_state->exception_index = EXCP_HLT;
 198     cpu_loop_exit(target_cpu_state);
 199     /* notreached */
 200
 201     return QEMU_ARM_POWERCTL_RET_SUCCESS;
 202 }
 203
 204 int arm_reset_cpu(uint64_t cpuid)
 205 {
 206     CPUState *target_cpu_state;
 207     ARMCPU *target_cpu;
 208
 209     DPRINTF("cpu %" PRId64 "\n", cpuid);
 210
 211     /* change to the cpu we are resetting */
 212     target_cpu_state = arm_get_cpu_by_id(cpuid);
 213     if (!target_cpu_state) {
 214         return QEMU_ARM_POWERCTL_INVALID_PARAM;
 215     }
 216     target_cpu = ARM_CPU(target_cpu_state);
 217     if (target_cpu->powered_off) {
 218         qemu_log_mask(LOG_GUEST_ERROR,
 219                       "[ARM]%s: CPU %" PRId64 " is off\n",
 220                       __func__, cpuid);
 221         return QEMU_ARM_POWERCTL_IS_OFF;
 222     }
 223
 224     /* Reset the cpu */
 225     cpu_reset(target_cpu_state);
 226
 227     return QEMU_ARM_POWERCTL_RET_SUCCESS;
 228 }