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qemu-e2k/hw/timer/etraxfs_timer.c
Peter Maydell b01422622b ptimer: Rename ptimer_init() to ptimer_init_with_bh() 
Currently the ptimer design uses a QEMU bottom-half as its
mechanism for calling back into the device model using the
ptimer when the timer has expired. Unfortunately this design
is fatally flawed, because it means that there is a lag
between the ptimer updating its own state and the device
callback function updating device state, and guest accesses
to device registers between the two can return inconsistent
device state.

We want to replace the bottom-half design with one where
the guest device's callback is called either immediately
(when the ptimer triggers by timeout) or when the device
model code closes a transaction-begin/end section (when the
ptimer triggers because the device model changed the
ptimer's count value or other state). As the first step,
rename ptimer_init() to ptimer_init_with_bh(), to free up
the ptimer_init() name for the new API. We can then convert
all the ptimer users away from ptimer_init_with_bh() before
removing it entirely.

(Commit created with
 git grep -l ptimer_init | xargs sed -i -e 's/ptimer_init/ptimer_init_with_bh/'
and three overlong lines folded by hand.)

Signed-off-by: Peter Maydell <peter.maydell@linaro.org>
Reviewed-by: Richard Henderson <richard.henderson@linaro.org>
Message-id: 20191008171740.9679-2-peter.maydell@linaro.org
2019-10-15 18:09:02 +01:00

364 lines
9.2 KiB
C
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/*
* QEMU ETRAX Timers
*
* Copyright (c) 2007 Edgar E. Iglesias, Axis Communications AB.
*
* 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 "qemu/osdep.h"
#include "hw/sysbus.h"
#include "sysemu/reset.h"
#include "sysemu/runstate.h"
#include "qemu/main-loop.h"
#include "qemu/module.h"
#include "qemu/timer.h"
#include "hw/irq.h"
#include "hw/ptimer.h"
#define D(x)
#define RW_TMR0_DIV 0x00
#define R_TMR0_DATA 0x04
#define RW_TMR0_CTRL 0x08
#define RW_TMR1_DIV 0x10
#define R_TMR1_DATA 0x14
#define RW_TMR1_CTRL 0x18
#define R_TIME 0x38
#define RW_WD_CTRL 0x40
#define R_WD_STAT 0x44
#define RW_INTR_MASK 0x48
#define RW_ACK_INTR 0x4c
#define R_INTR 0x50
#define R_MASKED_INTR 0x54
#define TYPE_ETRAX_FS_TIMER "etraxfs,timer"
#define ETRAX_TIMER(obj) \
OBJECT_CHECK(ETRAXTimerState, (obj), TYPE_ETRAX_FS_TIMER)
typedef struct ETRAXTimerState {
SysBusDevice parent_obj;
MemoryRegion mmio;
qemu_irq irq;
qemu_irq nmi;
QEMUBH *bh_t0;
QEMUBH *bh_t1;
QEMUBH *bh_wd;
ptimer_state *ptimer_t0;
ptimer_state *ptimer_t1;
ptimer_state *ptimer_wd;
int wd_hits;
/* Control registers. */
uint32_t rw_tmr0_div;
uint32_t r_tmr0_data;
uint32_t rw_tmr0_ctrl;
uint32_t rw_tmr1_div;
uint32_t r_tmr1_data;
uint32_t rw_tmr1_ctrl;
uint32_t rw_wd_ctrl;
uint32_t rw_intr_mask;
uint32_t rw_ack_intr;
uint32_t r_intr;
uint32_t r_masked_intr;
} ETRAXTimerState;
static uint64_t
timer_read(void *opaque, hwaddr addr, unsigned int size)
{
ETRAXTimerState *t = opaque;
uint32_t r = 0;
switch (addr) {
case R_TMR0_DATA:
r = ptimer_get_count(t->ptimer_t0);
break;
case R_TMR1_DATA:
r = ptimer_get_count(t->ptimer_t1);
break;
case R_TIME:
r = qemu_clock_get_ns(QEMU_CLOCK_VIRTUAL) / 10;
break;
case RW_INTR_MASK:
r = t->rw_intr_mask;
break;
case R_MASKED_INTR:
r = t->r_intr & t->rw_intr_mask;
break;
default:
D(printf ("%s %x\n", __func__, addr));
break;
}
return r;
}
static void update_ctrl(ETRAXTimerState *t, int tnum)
{
unsigned int op;
unsigned int freq;
unsigned int freq_hz;
unsigned int div;
uint32_t ctrl;
ptimer_state *timer;
if (tnum == 0) {
ctrl = t->rw_tmr0_ctrl;
div = t->rw_tmr0_div;
timer = t->ptimer_t0;
} else {
ctrl = t->rw_tmr1_ctrl;
div = t->rw_tmr1_div;
timer = t->ptimer_t1;
}
op = ctrl & 3;
freq = ctrl >> 2;
freq_hz = 32000000;
switch (freq)
{
case 0:
case 1:
D(printf ("extern or disabled timer clock?\n"));
break;
case 4: freq_hz = 29493000; break;
case 5: freq_hz = 32000000; break;
case 6: freq_hz = 32768000; break;
case 7: freq_hz = 100000000; break;
default:
abort();
break;
}
D(printf ("freq_hz=%d div=%d\n", freq_hz, div));
ptimer_set_freq(timer, freq_hz);
ptimer_set_limit(timer, div, 0);
switch (op)
{
case 0:
/* Load. */
ptimer_set_limit(timer, div, 1);
break;
case 1:
/* Hold. */
ptimer_stop(timer);
break;
case 2:
/* Run. */
ptimer_run(timer, 0);
break;
default:
abort();
break;
}
}
static void timer_update_irq(ETRAXTimerState *t)
{
t->r_intr &= ~(t->rw_ack_intr);
t->r_masked_intr = t->r_intr & t->rw_intr_mask;
D(printf("%s: masked_intr=%x\n", __func__, t->r_masked_intr));
qemu_set_irq(t->irq, !!t->r_masked_intr);
}
static void timer0_hit(void *opaque)
{
ETRAXTimerState *t = opaque;
t->r_intr |= 1;
timer_update_irq(t);
}
static void timer1_hit(void *opaque)
{
ETRAXTimerState *t = opaque;
t->r_intr |= 2;
timer_update_irq(t);
}
static void watchdog_hit(void *opaque)
{
ETRAXTimerState *t = opaque;
if (t->wd_hits == 0) {
/* real hw gives a single tick before reseting but we are
a bit friendlier to compensate for our slower execution. */
ptimer_set_count(t->ptimer_wd, 10);
ptimer_run(t->ptimer_wd, 1);
qemu_irq_raise(t->nmi);
}
else
qemu_system_reset_request(SHUTDOWN_CAUSE_GUEST_RESET);
t->wd_hits++;
}
static inline void timer_watchdog_update(ETRAXTimerState *t, uint32_t value)
{
unsigned int wd_en = t->rw_wd_ctrl & (1 << 8);
unsigned int wd_key = t->rw_wd_ctrl >> 9;
unsigned int wd_cnt = t->rw_wd_ctrl & 511;
unsigned int new_key = value >> 9 & ((1 << 7) - 1);
unsigned int new_cmd = (value >> 8) & 1;
/* If the watchdog is enabled, they written key must match the
complement of the previous. */
wd_key = ~wd_key & ((1 << 7) - 1);
if (wd_en && wd_key != new_key)
return;
D(printf("en=%d new_key=%x oldkey=%x cmd=%d cnt=%d\n",
wd_en, new_key, wd_key, new_cmd, wd_cnt));
if (t->wd_hits)
qemu_irq_lower(t->nmi);
t->wd_hits = 0;
ptimer_set_freq(t->ptimer_wd, 760);
if (wd_cnt == 0)
wd_cnt = 256;
ptimer_set_count(t->ptimer_wd, wd_cnt);
if (new_cmd)
ptimer_run(t->ptimer_wd, 1);
else
ptimer_stop(t->ptimer_wd);
t->rw_wd_ctrl = value;
}
static void
timer_write(void *opaque, hwaddr addr,
uint64_t val64, unsigned int size)
{
ETRAXTimerState *t = opaque;
uint32_t value = val64;
switch (addr)
{
case RW_TMR0_DIV:
t->rw_tmr0_div = value;
break;
case RW_TMR0_CTRL:
D(printf ("RW_TMR0_CTRL=%x\n", value));
t->rw_tmr0_ctrl = value;
update_ctrl(t, 0);
break;
case RW_TMR1_DIV:
t->rw_tmr1_div = value;
break;
case RW_TMR1_CTRL:
D(printf ("RW_TMR1_CTRL=%x\n", value));
t->rw_tmr1_ctrl = value;
update_ctrl(t, 1);
break;
case RW_INTR_MASK:
D(printf ("RW_INTR_MASK=%x\n", value));
t->rw_intr_mask = value;
timer_update_irq(t);
break;
case RW_WD_CTRL:
timer_watchdog_update(t, value);
break;
case RW_ACK_INTR:
t->rw_ack_intr = value;
timer_update_irq(t);
t->rw_ack_intr = 0;
break;
default:
printf ("%s " TARGET_FMT_plx " %x\n",
__func__, addr, value);
break;
}
}
static const MemoryRegionOps timer_ops = {
.read = timer_read,
.write = timer_write,
.endianness = DEVICE_LITTLE_ENDIAN,
.valid = {
.min_access_size = 4,
.max_access_size = 4
}
};
static void etraxfs_timer_reset(void *opaque)
{
ETRAXTimerState *t = opaque;
ptimer_stop(t->ptimer_t0);
ptimer_stop(t->ptimer_t1);
ptimer_stop(t->ptimer_wd);
t->rw_wd_ctrl = 0;
t->r_intr = 0;
t->rw_intr_mask = 0;
qemu_irq_lower(t->irq);
}
static void etraxfs_timer_realize(DeviceState *dev, Error **errp)
{
ETRAXTimerState *t = ETRAX_TIMER(dev);
SysBusDevice *sbd = SYS_BUS_DEVICE(dev);
t->bh_t0 = qemu_bh_new(timer0_hit, t);
t->bh_t1 = qemu_bh_new(timer1_hit, t);
t->bh_wd = qemu_bh_new(watchdog_hit, t);
t->ptimer_t0 = ptimer_init_with_bh(t->bh_t0, PTIMER_POLICY_DEFAULT);
t->ptimer_t1 = ptimer_init_with_bh(t->bh_t1, PTIMER_POLICY_DEFAULT);
t->ptimer_wd = ptimer_init_with_bh(t->bh_wd, PTIMER_POLICY_DEFAULT);
sysbus_init_irq(sbd, &t->irq);
sysbus_init_irq(sbd, &t->nmi);
memory_region_init_io(&t->mmio, OBJECT(t), &timer_ops, t,
"etraxfs-timer", 0x5c);
sysbus_init_mmio(sbd, &t->mmio);
qemu_register_reset(etraxfs_timer_reset, t);
}
static void etraxfs_timer_class_init(ObjectClass *klass, void *data)
{
DeviceClass *dc = DEVICE_CLASS(klass);
dc->realize = etraxfs_timer_realize;
}
static const TypeInfo etraxfs_timer_info = {
.name = TYPE_ETRAX_FS_TIMER,
.parent = TYPE_SYS_BUS_DEVICE,
.instance_size = sizeof(ETRAXTimerState),
.class_init = etraxfs_timer_class_init,
};
static void etraxfs_timer_register_types(void)
{
type_register_static(&etraxfs_timer_info);
}
type_init(etraxfs_timer_register_types)
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