qemu

a9gtimer.c (11635B)

---

 /*
  * Global peripheral timer block for ARM A9MP
  *
  * (C) 2013 Xilinx Inc.
  *
  * Written by François LEGAL
  * Written by Peter Crosthwaite <peter.crosthwaite@xilinx.com>
  *
  * 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 "qemu/osdep.h"
 #include "hw/hw.h"
 #include "hw/irq.h"
 #include "hw/qdev-properties.h"
 #include "hw/timer/a9gtimer.h"
 #include "migration/vmstate.h"
 #include "qapi/error.h"
 #include "qemu/timer.h"
 #include "qemu/bitops.h"
 #include "qemu/log.h"
 #include "qemu/module.h"
 #include "hw/core/cpu.h"
 
 #ifndef A9_GTIMER_ERR_DEBUG
 #define A9_GTIMER_ERR_DEBUG 0
 #endif
 
 #define DB_PRINT_L(level, ...) do { \
     if (A9_GTIMER_ERR_DEBUG > (level)) { \
         fprintf(stderr,  ": %s: ", __func__); \
         fprintf(stderr, ## __VA_ARGS__); \
     } \
 } while (0)
 
 #define DB_PRINT(...) DB_PRINT_L(0, ## __VA_ARGS__)
 
 static inline int a9_gtimer_get_current_cpu(A9GTimerState *s)
 {
     if (current_cpu->cpu_index >= s->num_cpu) {
         hw_error("a9gtimer: num-cpu %d but this cpu is %d!\n",
                  s->num_cpu, current_cpu->cpu_index);
     }
     return current_cpu->cpu_index;
 }
 
 static inline uint64_t a9_gtimer_get_conv(A9GTimerState *s)
 {
     uint64_t prescale = extract32(s->control, R_CONTROL_PRESCALER_SHIFT,
                                   R_CONTROL_PRESCALER_LEN);
 
     return (prescale + 1) * 10;
 }
 
 static A9GTimerUpdate a9_gtimer_get_update(A9GTimerState *s)
 {
     A9GTimerUpdate ret;
 
     ret.now = qemu_clock_get_ns(QEMU_CLOCK_VIRTUAL);
     ret.new = s->ref_counter +
               (ret.now - s->cpu_ref_time) / a9_gtimer_get_conv(s);
     return ret;
 }
 
 static void a9_gtimer_update(A9GTimerState *s, bool sync)
 {
 
     A9GTimerUpdate update = a9_gtimer_get_update(s);
     int i;
     int64_t next_cdiff = 0;
 
     for (i = 0; i < s->num_cpu; ++i) {
         A9GTimerPerCPU *gtb = &s->per_cpu[i];
         int64_t cdiff = 0;
 
         if ((s->control & R_CONTROL_TIMER_ENABLE) &&
                 (gtb->control & R_CONTROL_COMP_ENABLE)) {
             /* R2p0+, where the compare function is >= */
             if (gtb->compare < update.new) {
                 DB_PRINT("Compare event happened for CPU %d\n", i);
                 gtb->status = 1;
                 if (gtb->control & R_CONTROL_AUTO_INCREMENT && gtb->inc) {
                     uint64_t inc =
                         QEMU_ALIGN_UP(update.new - gtb->compare, gtb->inc);
                     DB_PRINT("Auto incrementing timer compare by %"
                                                         PRId64 "\n", inc);
                     gtb->compare += inc;
                 }
             }
             cdiff = (int64_t)gtb->compare - (int64_t)update.new + 1;
             if (cdiff > 0 && (cdiff < next_cdiff || !next_cdiff)) {
                 next_cdiff = cdiff;
             }
         }
 
         qemu_set_irq(gtb->irq,
                      gtb->status && (gtb->control & R_CONTROL_IRQ_ENABLE));
     }
 
     timer_del(s->timer);
     if (next_cdiff) {
         DB_PRINT("scheduling qemu_timer to fire again in %"
                  PRIx64 " cycles\n", next_cdiff);
         timer_mod(s->timer, update.now + next_cdiff * a9_gtimer_get_conv(s));
     }
 
     if (s->control & R_CONTROL_TIMER_ENABLE) {
         s->counter = update.new;
     }
 
     if (sync) {
         s->cpu_ref_time = update.now;
         s->ref_counter = s->counter;
     }
 }
 
 static void a9_gtimer_update_no_sync(void *opaque)
 {
     A9GTimerState *s = A9_GTIMER(opaque);
 
     a9_gtimer_update(s, false);
 }
 
 static uint64_t a9_gtimer_read(void *opaque, hwaddr addr, unsigned size)
 {
     A9GTimerPerCPU *gtb = (A9GTimerPerCPU *)opaque;
     A9GTimerState *s = gtb->parent;
     A9GTimerUpdate update;
     uint64_t ret = 0;
     int shift = 0;
 
     switch (addr) {
     case R_COUNTER_HI:
         shift = 32;
         /* fallthrough */
     case R_COUNTER_LO:
         update = a9_gtimer_get_update(s);
         ret = extract64(update.new, shift, 32);
         break;
     case R_CONTROL:
         ret = s->control | gtb->control;
         break;
     case R_INTERRUPT_STATUS:
         ret = gtb->status;
         break;
     case R_COMPARATOR_HI:
         shift = 32;
         /* fallthrough */
     case R_COMPARATOR_LO:
         ret = extract64(gtb->compare, shift, 32);
         break;
     case R_AUTO_INCREMENT:
         ret =  gtb->inc;
         break;
     default:
         qemu_log_mask(LOG_GUEST_ERROR, "bad a9gtimer register: %x\n",
                       (unsigned)addr);
         return 0;
     }
 
     DB_PRINT("addr:%#x data:%#08" PRIx64 "\n", (unsigned)addr, ret);
     return ret;
 }
 
 static void a9_gtimer_write(void *opaque, hwaddr addr, uint64_t value,
                             unsigned size)
 {
     A9GTimerPerCPU *gtb = (A9GTimerPerCPU *)opaque;
     A9GTimerState *s = gtb->parent;
     int shift = 0;
 
     DB_PRINT("addr:%#x data:%#08" PRIx64 "\n", (unsigned)addr, value);
 
     switch (addr) {
     case R_COUNTER_HI:
         shift = 32;
         /* fallthrough */
     case R_COUNTER_LO:
         /*
          * Keep it simple - ARM docco explicitly says to disable timer before
          * modding it, so don't bother trying to do all the difficult on the fly
          * timer modifications - (if they even work in real hardware??).
          */
         if (s->control & R_CONTROL_TIMER_ENABLE) {
             qemu_log_mask(LOG_GUEST_ERROR, "Cannot mod running ARM gtimer\n");
             return;
         }
         s->counter = deposit64(s->counter, shift, 32, value);
         return;
     case R_CONTROL:
         a9_gtimer_update(s, (value ^ s->control) & R_CONTROL_NEEDS_SYNC);
         gtb->control = value & R_CONTROL_BANKED;
         s->control = value & ~R_CONTROL_BANKED;
         break;
     case R_INTERRUPT_STATUS:
         a9_gtimer_update(s, false);
         gtb->status &= ~value;
         break;
     case R_COMPARATOR_HI:
         shift = 32;
         /* fallthrough */
     case R_COMPARATOR_LO:
         a9_gtimer_update(s, false);
         gtb->compare = deposit64(gtb->compare, shift, 32, value);
         break;
     case R_AUTO_INCREMENT:
         gtb->inc = value;
         return;
     default:
         return;
     }
 
     a9_gtimer_update(s, false);
 }
 
 /* Wrapper functions to implement the "read global timer for
  * the current CPU" memory regions.
  */
 static uint64_t a9_gtimer_this_read(void *opaque, hwaddr addr,
                                     unsigned size)
 {
     A9GTimerState *s = A9_GTIMER(opaque);
     int id = a9_gtimer_get_current_cpu(s);
 
     /* no \n so concatenates with message from read fn */
     DB_PRINT("CPU:%d:", id);
 
     return a9_gtimer_read(&s->per_cpu[id], addr, size);
 }
 
 static void a9_gtimer_this_write(void *opaque, hwaddr addr,
                                  uint64_t value, unsigned size)
 {
     A9GTimerState *s = A9_GTIMER(opaque);
     int id = a9_gtimer_get_current_cpu(s);
 
     /* no \n so concatenates with message from write fn */
     DB_PRINT("CPU:%d:", id);
 
     a9_gtimer_write(&s->per_cpu[id], addr, value, size);
 }
 
 static const MemoryRegionOps a9_gtimer_this_ops = {
     .read = a9_gtimer_this_read,
     .write = a9_gtimer_this_write,
     .valid = {
         .min_access_size = 4,
         .max_access_size = 4,
     },
     .endianness = DEVICE_NATIVE_ENDIAN,
 };
 
 static const MemoryRegionOps a9_gtimer_ops = {
     .read = a9_gtimer_read,
     .write = a9_gtimer_write,
     .valid = {
         .min_access_size = 4,
         .max_access_size = 4,
     },
     .endianness = DEVICE_NATIVE_ENDIAN,
 };
 
 static void a9_gtimer_reset(DeviceState *dev)
 {
     A9GTimerState *s = A9_GTIMER(dev);
     int i;
 
     s->counter = 0;
     s->control = 0;
 
     for (i = 0; i < s->num_cpu; i++) {
         A9GTimerPerCPU *gtb = &s->per_cpu[i];
 
         gtb->control = 0;
         gtb->status = 0;
         gtb->compare = 0;
         gtb->inc = 0;
     }
     a9_gtimer_update(s, false);
 }
 
 static void a9_gtimer_realize(DeviceState *dev, Error **errp)
 {
     A9GTimerState *s = A9_GTIMER(dev);
     SysBusDevice *sbd = SYS_BUS_DEVICE(dev);
     int i;
 
     if (s->num_cpu < 1 || s->num_cpu > A9_GTIMER_MAX_CPUS) {
         error_setg(errp, "%s: num-cpu must be between 1 and %d",
                    __func__, A9_GTIMER_MAX_CPUS);
         return;
     }
 
     memory_region_init_io(&s->iomem, OBJECT(dev), &a9_gtimer_this_ops, s,
                           "a9gtimer shared", 0x20);
     sysbus_init_mmio(sbd, &s->iomem);
     s->timer = timer_new_ns(QEMU_CLOCK_VIRTUAL, a9_gtimer_update_no_sync, s);
 
     for (i = 0; i < s->num_cpu; i++) {
         A9GTimerPerCPU *gtb = &s->per_cpu[i];
 
         gtb->parent = s;
         sysbus_init_irq(sbd, &gtb->irq);
         memory_region_init_io(&gtb->iomem, OBJECT(dev), &a9_gtimer_ops, gtb,
                               "a9gtimer per cpu", 0x20);
         sysbus_init_mmio(sbd, &gtb->iomem);
     }
 }
 
 static bool vmstate_a9_gtimer_control_needed(void *opaque)
 {
     A9GTimerState *s = opaque;
     return s->control != 0;
 }
 
 static const VMStateDescription vmstate_a9_gtimer_per_cpu = {
     .name = "arm.cortex-a9-global-timer.percpu",
     .version_id = 1,
     .minimum_version_id = 1,
     .fields = (VMStateField[]) {
         VMSTATE_UINT32(control, A9GTimerPerCPU),
         VMSTATE_UINT64(compare, A9GTimerPerCPU),
         VMSTATE_UINT32(status, A9GTimerPerCPU),
         VMSTATE_UINT32(inc, A9GTimerPerCPU),
         VMSTATE_END_OF_LIST()
     }
 };
 
 static const VMStateDescription vmstate_a9_gtimer_control = {
     .name = "arm.cortex-a9-global-timer.control",
     .version_id = 1,
     .minimum_version_id = 1,
     .needed = vmstate_a9_gtimer_control_needed,
     .fields = (VMStateField[]) {
         VMSTATE_UINT32(control, A9GTimerState),
         VMSTATE_END_OF_LIST()
     }
 };
 
 static const VMStateDescription vmstate_a9_gtimer = {
     .name = "arm.cortex-a9-global-timer",
     .version_id = 1,
     .minimum_version_id = 1,
     .fields = (VMStateField[]) {
         VMSTATE_TIMER_PTR(timer, A9GTimerState),
         VMSTATE_UINT64(counter, A9GTimerState),
         VMSTATE_UINT64(ref_counter, A9GTimerState),
         VMSTATE_UINT64(cpu_ref_time, A9GTimerState),
         VMSTATE_STRUCT_VARRAY_UINT32(per_cpu, A9GTimerState, num_cpu,
                                      1, vmstate_a9_gtimer_per_cpu,
                                      A9GTimerPerCPU),
         VMSTATE_END_OF_LIST()
     },
     .subsections = (const VMStateDescription*[]) {
         &vmstate_a9_gtimer_control,
         NULL
     }
 };
 
 static Property a9_gtimer_properties[] = {
     DEFINE_PROP_UINT32("num-cpu", A9GTimerState, num_cpu, 0),
     DEFINE_PROP_END_OF_LIST()
 };
 
 static void a9_gtimer_class_init(ObjectClass *klass, void *data)
 {
     DeviceClass *dc = DEVICE_CLASS(klass);
 
     dc->realize = a9_gtimer_realize;
     dc->vmsd = &vmstate_a9_gtimer;
     dc->reset = a9_gtimer_reset;
     device_class_set_props(dc, a9_gtimer_properties);
 }
 
 static const TypeInfo a9_gtimer_info = {
     .name          = TYPE_A9_GTIMER,
     .parent        = TYPE_SYS_BUS_DEVICE,
     .instance_size = sizeof(A9GTimerState),
     .class_init    = a9_gtimer_class_init,
 };
 
 static void a9_gtimer_register_types(void)
 {
     type_register_static(&a9_gtimer_info);
 }
 
 type_init(a9_gtimer_register_types)