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qemu-e2k/hw/slavio_timer.c
Blue Swirl 68fb89a2c0 sparc32: improve timer implementation 
Timer with zero period (free-run) will never match.

Timer counting starts with tick value of 0x200, not from 0,
so the period must calculated from one tick less than the limit.

Signed-off-by: Blue Swirl <blauwirbel@gmail.com>
2010-04-03 06:17:35 +00:00

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/*
* QEMU Sparc SLAVIO timer controller emulation
*
* Copyright (c) 2003-2005 Fabrice Bellard
*
* Permission is hereby granted, free of charge, to any person obtaining a copy
* of this software and associated documentation files (the "Software"), to deal
* in the Software without restriction, including without limitation the rights
* to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
* copies of the Software, and to permit persons to whom the Software is
* furnished to do so, subject to the following conditions:
*
* The above copyright notice and this permission notice shall be included in
* all copies or substantial portions of the Software.
*
* THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
* IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
* FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL
* THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
* LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
* OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN
* THE SOFTWARE.
*/
#include "sun4m.h"
#include "qemu-timer.h"
#include "sysbus.h"
//#define DEBUG_TIMER
#ifdef DEBUG_TIMER
#define DPRINTF(fmt, ...) \
do { printf("TIMER: " fmt , ## __VA_ARGS__); } while (0)
#else
#define DPRINTF(fmt, ...) do {} while (0)
#endif
/*
* Registers of hardware timer in sun4m.
*
* This is the timer/counter part of chip STP2001 (Slave I/O), also
* produced as NCR89C105. See
* http://www.ibiblio.org/pub/historic-linux/early-ports/Sparc/NCR/NCR89C105.txt
*
* The 31-bit counter is incremented every 500ns by bit 9. Bits 8..0
* are zero. Bit 31 is 1 when count has been reached.
*
* Per-CPU timers interrupt local CPU, system timer uses normal
* interrupt routing.
*
*/
#define MAX_CPUS 16
typedef struct CPUTimerState {
qemu_irq irq;
ptimer_state *timer;
uint32_t count, counthigh, reached;
uint64_t limit;
// processor only
uint32_t running;
} CPUTimerState;
typedef struct SLAVIO_TIMERState {
SysBusDevice busdev;
uint32_t num_cpus;
CPUTimerState cputimer[MAX_CPUS + 1];
uint32_t cputimer_mode;
} SLAVIO_TIMERState;
typedef struct TimerContext {
SLAVIO_TIMERState *s;
unsigned int timer_index; /* 0 for system, 1 ... MAX_CPUS for CPU timers */
} TimerContext;
#define SYS_TIMER_SIZE 0x14
#define CPU_TIMER_SIZE 0x10
#define TIMER_LIMIT 0
#define TIMER_COUNTER 1
#define TIMER_COUNTER_NORST 2
#define TIMER_STATUS 3
#define TIMER_MODE 4
#define TIMER_COUNT_MASK32 0xfffffe00
#define TIMER_LIMIT_MASK32 0x7fffffff
#define TIMER_MAX_COUNT64 0x7ffffffffffffe00ULL
#define TIMER_MAX_COUNT32 0x7ffffe00ULL
#define TIMER_REACHED 0x80000000
#define TIMER_PERIOD 500ULL // 500ns
#define LIMIT_TO_PERIODS(l) (((l) >> 9) - 1)
#define PERIODS_TO_LIMIT(l) (((l) + 1) << 9)
static int slavio_timer_is_user(TimerContext *tc)
{
SLAVIO_TIMERState *s = tc->s;
unsigned int timer_index = tc->timer_index;
return timer_index != 0 && (s->cputimer_mode & (1 << (timer_index - 1)));
}
// Update count, set irq, update expire_time
// Convert from ptimer countdown units
static void slavio_timer_get_out(CPUTimerState *t)
{
uint64_t count, limit;
if (t->limit == 0) { /* free-run system or processor counter */
limit = TIMER_MAX_COUNT32;
} else {
limit = t->limit;
}
count = limit - PERIODS_TO_LIMIT(ptimer_get_count(t->timer));
DPRINTF("get_out: limit %" PRIx64 " count %x%08x\n", t->limit, t->counthigh,
t->count);
t->count = count & TIMER_COUNT_MASK32;
t->counthigh = count >> 32;
}
// timer callback
static void slavio_timer_irq(void *opaque)
{
TimerContext *tc = opaque;
SLAVIO_TIMERState *s = tc->s;
CPUTimerState *t = &s->cputimer[tc->timer_index];
slavio_timer_get_out(t);
DPRINTF("callback: count %x%08x\n", t->counthigh, t->count);
/* if limit is 0 (free-run), there will be no match */
if (t->limit != 0) {
t->reached = TIMER_REACHED;
}
/* there is no interrupt if user timer or free-run */
if (!slavio_timer_is_user(tc) && t->limit != 0) {
qemu_irq_raise(t->irq);
}
}
static uint32_t slavio_timer_mem_readl(void *opaque, target_phys_addr_t addr)
{
TimerContext *tc = opaque;
SLAVIO_TIMERState *s = tc->s;
uint32_t saddr, ret;
unsigned int timer_index = tc->timer_index;
CPUTimerState *t = &s->cputimer[timer_index];
saddr = addr >> 2;
switch (saddr) {
case TIMER_LIMIT:
// read limit (system counter mode) or read most signifying
// part of counter (user mode)
if (slavio_timer_is_user(tc)) {
// read user timer MSW
slavio_timer_get_out(t);
ret = t->counthigh | t->reached;
} else {
// read limit
// clear irq
qemu_irq_lower(t->irq);
t->reached = 0;
ret = t->limit & TIMER_LIMIT_MASK32;
}
break;
case TIMER_COUNTER:
// read counter and reached bit (system mode) or read lsbits
// of counter (user mode)
slavio_timer_get_out(t);
if (slavio_timer_is_user(tc)) { // read user timer LSW
ret = t->count & TIMER_MAX_COUNT64;
} else { // read limit
ret = (t->count & TIMER_MAX_COUNT32) |
t->reached;
}
break;
case TIMER_STATUS:
// only available in processor counter/timer
// read start/stop status
if (timer_index > 0) {
ret = t->running;
} else {
ret = 0;
}
break;
case TIMER_MODE:
// only available in system counter
// read user/system mode
ret = s->cputimer_mode;
break;
default:
DPRINTF("invalid read address " TARGET_FMT_plx "\n", addr);
ret = 0;
break;
}
DPRINTF("read " TARGET_FMT_plx " = %08x\n", addr, ret);
return ret;
}
static void slavio_timer_mem_writel(void *opaque, target_phys_addr_t addr,
uint32_t val)
{
TimerContext *tc = opaque;
SLAVIO_TIMERState *s = tc->s;
uint32_t saddr;
unsigned int timer_index = tc->timer_index;
CPUTimerState *t = &s->cputimer[timer_index];
DPRINTF("write " TARGET_FMT_plx " %08x\n", addr, val);
saddr = addr >> 2;
switch (saddr) {
case TIMER_LIMIT:
if (slavio_timer_is_user(tc)) {
uint64_t count;
// set user counter MSW, reset counter
t->limit = TIMER_MAX_COUNT64;
t->counthigh = val & (TIMER_MAX_COUNT64 >> 32);
t->reached = 0;
count = ((uint64_t)t->counthigh << 32) | t->count;
DPRINTF("processor %d user timer set to %016" PRIx64 "\n",
timer_index, count);
ptimer_set_count(t->timer, LIMIT_TO_PERIODS(t->limit - count));
} else {
// set limit, reset counter
qemu_irq_lower(t->irq);
t->limit = val & TIMER_MAX_COUNT32;
if (t->timer) {
if (t->limit == 0) { /* free-run */
ptimer_set_limit(t->timer,
LIMIT_TO_PERIODS(TIMER_MAX_COUNT32), 1);
} else {
ptimer_set_limit(t->timer, LIMIT_TO_PERIODS(t->limit), 1);
}
}
}
break;
case TIMER_COUNTER:
if (slavio_timer_is_user(tc)) {
uint64_t count;
// set user counter LSW, reset counter
t->limit = TIMER_MAX_COUNT64;
t->count = val & TIMER_MAX_COUNT64;
t->reached = 0;
count = ((uint64_t)t->counthigh) << 32 | t->count;
DPRINTF("processor %d user timer set to %016" PRIx64 "\n",
timer_index, count);
ptimer_set_count(t->timer, LIMIT_TO_PERIODS(t->limit - count));
} else
DPRINTF("not user timer\n");
break;
case TIMER_COUNTER_NORST:
// set limit without resetting counter
t->limit = val & TIMER_MAX_COUNT32;
if (t->limit == 0) { /* free-run */
ptimer_set_limit(t->timer, LIMIT_TO_PERIODS(TIMER_MAX_COUNT32), 0);
} else {
ptimer_set_limit(t->timer, LIMIT_TO_PERIODS(t->limit), 0);
}
break;
case TIMER_STATUS:
if (slavio_timer_is_user(tc)) {
// start/stop user counter
if ((val & 1) && !t->running) {
DPRINTF("processor %d user timer started\n",
timer_index);
ptimer_run(t->timer, 0);
t->running = 1;
} else if (!(val & 1) && t->running) {
DPRINTF("processor %d user timer stopped\n",
timer_index);
ptimer_stop(t->timer);
t->running = 0;
}
}
break;
case TIMER_MODE:
if (timer_index == 0) {
unsigned int i;
for (i = 0; i < s->num_cpus; i++) {
unsigned int processor = 1 << i;
CPUTimerState *curr_timer = &s->cputimer[i + 1];
// check for a change in timer mode for this processor
if ((val & processor) != (s->cputimer_mode & processor)) {
if (val & processor) { // counter -> user timer
qemu_irq_lower(curr_timer->irq);
// counters are always running
ptimer_stop(curr_timer->timer);
curr_timer->running = 0;
// user timer limit is always the same
curr_timer->limit = TIMER_MAX_COUNT64;
ptimer_set_limit(curr_timer->timer,
LIMIT_TO_PERIODS(curr_timer->limit),
1);
// set this processors user timer bit in config
// register
s->cputimer_mode |= processor;
DPRINTF("processor %d changed from counter to user "
"timer\n", timer_index);
} else { // user timer -> counter
// stop the user timer if it is running
if (curr_timer->running) {
ptimer_stop(curr_timer->timer);
}
// start the counter
ptimer_run(curr_timer->timer, 0);
curr_timer->running = 1;
// clear this processors user timer bit in config
// register
s->cputimer_mode &= ~processor;
DPRINTF("processor %d changed from user timer to "
"counter\n", timer_index);
}
}
}
} else {
DPRINTF("not system timer\n");
}
break;
default:
DPRINTF("invalid write address " TARGET_FMT_plx "\n", addr);
break;
}
}
static CPUReadMemoryFunc * const slavio_timer_mem_read[3] = {
NULL,
NULL,
slavio_timer_mem_readl,
};
static CPUWriteMemoryFunc * const slavio_timer_mem_write[3] = {
NULL,
NULL,
slavio_timer_mem_writel,
};
static const VMStateDescription vmstate_timer = {
.name ="timer",
.version_id = 3,
.minimum_version_id = 3,
.minimum_version_id_old = 3,
.fields = (VMStateField []) {
VMSTATE_UINT64(limit, CPUTimerState),
VMSTATE_UINT32(count, CPUTimerState),
VMSTATE_UINT32(counthigh, CPUTimerState),
VMSTATE_UINT32(reached, CPUTimerState),
VMSTATE_UINT32(running, CPUTimerState),
VMSTATE_PTIMER(timer, CPUTimerState),
VMSTATE_END_OF_LIST()
}
};
static const VMStateDescription vmstate_slavio_timer = {
.name ="slavio_timer",
.version_id = 3,
.minimum_version_id = 3,
.minimum_version_id_old = 3,
.fields = (VMStateField []) {
VMSTATE_STRUCT_ARRAY(cputimer, SLAVIO_TIMERState, MAX_CPUS + 1, 3,
vmstate_timer, CPUTimerState),
VMSTATE_END_OF_LIST()
}
};
static void slavio_timer_reset(DeviceState *d)
{
SLAVIO_TIMERState *s = container_of(d, SLAVIO_TIMERState, busdev.qdev);
unsigned int i;
CPUTimerState *curr_timer;
for (i = 0; i <= MAX_CPUS; i++) {
curr_timer = &s->cputimer[i];
curr_timer->limit = 0;
curr_timer->count = 0;
curr_timer->reached = 0;
if (i < s->num_cpus) {
ptimer_set_limit(curr_timer->timer,
LIMIT_TO_PERIODS(TIMER_MAX_COUNT32), 1);
ptimer_run(curr_timer->timer, 0);
}
curr_timer->running = 1;
}
s->cputimer_mode = 0;
}
static int slavio_timer_init1(SysBusDevice *dev)
{
int io;
SLAVIO_TIMERState *s = FROM_SYSBUS(SLAVIO_TIMERState, dev);
QEMUBH *bh;
unsigned int i;
TimerContext *tc;
for (i = 0; i <= MAX_CPUS; i++) {
tc = qemu_mallocz(sizeof(TimerContext));
tc->s = s;
tc->timer_index = i;
bh = qemu_bh_new(slavio_timer_irq, tc);
s->cputimer[i].timer = ptimer_init(bh);
ptimer_set_period(s->cputimer[i].timer, TIMER_PERIOD);
io = cpu_register_io_memory(slavio_timer_mem_read,
slavio_timer_mem_write, tc);
if (i == 0) {
sysbus_init_mmio(dev, SYS_TIMER_SIZE, io);
} else {
sysbus_init_mmio(dev, CPU_TIMER_SIZE, io);
}
sysbus_init_irq(dev, &s->cputimer[i].irq);
}
return 0;
}
static SysBusDeviceInfo slavio_timer_info = {
.init = slavio_timer_init1,
.qdev.name = "slavio_timer",
.qdev.size = sizeof(SLAVIO_TIMERState),
.qdev.vmsd = &vmstate_slavio_timer,
.qdev.reset = slavio_timer_reset,
.qdev.props = (Property[]) {
DEFINE_PROP_UINT32("num_cpus", SLAVIO_TIMERState, num_cpus, 0),
DEFINE_PROP_END_OF_LIST(),
}
};
static void slavio_timer_register_devices(void)
{
sysbus_register_withprop(&slavio_timer_info);
}
device_init(slavio_timer_register_devices)
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