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qemu-e2k/hw/timer/sh_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

337 lines
8.9 KiB
C
Raw Blame History

/*
* SuperH Timer modules.
*
* Copyright (c) 2007 Magnus Damm
* Based on arm_timer.c by Paul Brook
* Copyright (c) 2005-2006 CodeSourcery.
*
* This code is licensed under the GPL.
*/
#include "qemu/osdep.h"
#include "hw/hw.h"
#include "hw/irq.h"
#include "hw/sh4/sh.h"
#include "qemu/timer.h"
#include "qemu/main-loop.h"
#include "hw/ptimer.h"
//#define DEBUG_TIMER
#define TIMER_TCR_TPSC (7 << 0)
#define TIMER_TCR_CKEG (3 << 3)
#define TIMER_TCR_UNIE (1 << 5)
#define TIMER_TCR_ICPE (3 << 6)
#define TIMER_TCR_UNF (1 << 8)
#define TIMER_TCR_ICPF (1 << 9)
#define TIMER_TCR_RESERVED (0x3f << 10)
#define TIMER_FEAT_CAPT (1 << 0)
#define TIMER_FEAT_EXTCLK (1 << 1)
#define OFFSET_TCOR 0
#define OFFSET_TCNT 1
#define OFFSET_TCR 2
#define OFFSET_TCPR 3
typedef struct {
ptimer_state *timer;
uint32_t tcnt;
uint32_t tcor;
uint32_t tcr;
uint32_t tcpr;
int freq;
int int_level;
int old_level;
int feat;
int enabled;
qemu_irq irq;
} sh_timer_state;
/* Check all active timers, and schedule the next timer interrupt. */
static void sh_timer_update(sh_timer_state *s)
{
int new_level = s->int_level && (s->tcr & TIMER_TCR_UNIE);
if (new_level != s->old_level)
qemu_set_irq (s->irq, new_level);
s->old_level = s->int_level;
s->int_level = new_level;
}
static uint32_t sh_timer_read(void *opaque, hwaddr offset)
{
sh_timer_state *s = (sh_timer_state *)opaque;
switch (offset >> 2) {
case OFFSET_TCOR:
return s->tcor;
case OFFSET_TCNT:
return ptimer_get_count(s->timer);
case OFFSET_TCR:
return s->tcr | (s->int_level ? TIMER_TCR_UNF : 0);
case OFFSET_TCPR:
if (s->feat & TIMER_FEAT_CAPT)
return s->tcpr;
/* fall through */
default:
hw_error("sh_timer_read: Bad offset %x\n", (int)offset);
return 0;
}
}
static void sh_timer_write(void *opaque, hwaddr offset,
uint32_t value)
{
sh_timer_state *s = (sh_timer_state *)opaque;
int freq;
switch (offset >> 2) {
case OFFSET_TCOR:
s->tcor = value;
ptimer_set_limit(s->timer, s->tcor, 0);
break;
case OFFSET_TCNT:
s->tcnt = value;
ptimer_set_count(s->timer, s->tcnt);
break;
case OFFSET_TCR:
if (s->enabled) {
/* Pause the timer if it is running. This may cause some
inaccuracy dure to rounding, but avoids a whole lot of other
messyness. */
ptimer_stop(s->timer);
}
freq = s->freq;
/* ??? Need to recalculate expiry time after changing divisor. */
switch (value & TIMER_TCR_TPSC) {
case 0: freq >>= 2; break;
case 1: freq >>= 4; break;
case 2: freq >>= 6; break;
case 3: freq >>= 8; break;
case 4: freq >>= 10; break;
case 6:
case 7: if (s->feat & TIMER_FEAT_EXTCLK) break;
default: hw_error("sh_timer_write: Reserved TPSC value\n"); break;
}
switch ((value & TIMER_TCR_CKEG) >> 3) {
case 0: break;
case 1:
case 2:
case 3: if (s->feat & TIMER_FEAT_EXTCLK) break;
default: hw_error("sh_timer_write: Reserved CKEG value\n"); break;
}
switch ((value & TIMER_TCR_ICPE) >> 6) {
case 0: break;
case 2:
case 3: if (s->feat & TIMER_FEAT_CAPT) break;
default: hw_error("sh_timer_write: Reserved ICPE value\n"); break;
}
if ((value & TIMER_TCR_UNF) == 0)
s->int_level = 0;
value &= ~TIMER_TCR_UNF;
if ((value & TIMER_TCR_ICPF) && (!(s->feat & TIMER_FEAT_CAPT)))
hw_error("sh_timer_write: Reserved ICPF value\n");
value &= ~TIMER_TCR_ICPF; /* capture not supported */
if (value & TIMER_TCR_RESERVED)
hw_error("sh_timer_write: Reserved TCR bits set\n");
s->tcr = value;
ptimer_set_limit(s->timer, s->tcor, 0);
ptimer_set_freq(s->timer, freq);
if (s->enabled) {
/* Restart the timer if still enabled. */
ptimer_run(s->timer, 0);
}
break;
case OFFSET_TCPR:
if (s->feat & TIMER_FEAT_CAPT) {
s->tcpr = value;
break;
}
default:
hw_error("sh_timer_write: Bad offset %x\n", (int)offset);
}
sh_timer_update(s);
}
static void sh_timer_start_stop(void *opaque, int enable)
{
sh_timer_state *s = (sh_timer_state *)opaque;
#ifdef DEBUG_TIMER
printf("sh_timer_start_stop %d (%d)\n", enable, s->enabled);
#endif
if (s->enabled && !enable) {
ptimer_stop(s->timer);
}
if (!s->enabled && enable) {
ptimer_run(s->timer, 0);
}
s->enabled = !!enable;
#ifdef DEBUG_TIMER
printf("sh_timer_start_stop done %d\n", s->enabled);
#endif
}
static void sh_timer_tick(void *opaque)
{
sh_timer_state *s = (sh_timer_state *)opaque;
s->int_level = s->enabled;
sh_timer_update(s);
}
static void *sh_timer_init(uint32_t freq, int feat, qemu_irq irq)
{
sh_timer_state *s;
QEMUBH *bh;
s = (sh_timer_state *)g_malloc0(sizeof(sh_timer_state));
s->freq = freq;
s->feat = feat;
s->tcor = 0xffffffff;
s->tcnt = 0xffffffff;
s->tcpr = 0xdeadbeef;
s->tcr = 0;
s->enabled = 0;
s->irq = irq;
bh = qemu_bh_new(sh_timer_tick, s);
s->timer = ptimer_init_with_bh(bh, PTIMER_POLICY_DEFAULT);
sh_timer_write(s, OFFSET_TCOR >> 2, s->tcor);
sh_timer_write(s, OFFSET_TCNT >> 2, s->tcnt);
sh_timer_write(s, OFFSET_TCPR >> 2, s->tcpr);
sh_timer_write(s, OFFSET_TCR >> 2, s->tcpr);
/* ??? Save/restore. */
return s;
}
typedef struct {
MemoryRegion iomem;
MemoryRegion iomem_p4;
MemoryRegion iomem_a7;
void *timer[3];
int level[3];
uint32_t tocr;
uint32_t tstr;
int feat;
} tmu012_state;
static uint64_t tmu012_read(void *opaque, hwaddr offset,
unsigned size)
{
tmu012_state *s = (tmu012_state *)opaque;
#ifdef DEBUG_TIMER
printf("tmu012_read 0x%lx\n", (unsigned long) offset);
#endif
if (offset >= 0x20) {
if (!(s->feat & TMU012_FEAT_3CHAN))
hw_error("tmu012_write: Bad channel offset %x\n", (int)offset);
return sh_timer_read(s->timer[2], offset - 0x20);
}
if (offset >= 0x14)
return sh_timer_read(s->timer[1], offset - 0x14);
if (offset >= 0x08)
return sh_timer_read(s->timer[0], offset - 0x08);
if (offset == 4)
return s->tstr;
if ((s->feat & TMU012_FEAT_TOCR) && offset == 0)
return s->tocr;
hw_error("tmu012_write: Bad offset %x\n", (int)offset);
return 0;
}
static void tmu012_write(void *opaque, hwaddr offset,
uint64_t value, unsigned size)
{
tmu012_state *s = (tmu012_state *)opaque;
#ifdef DEBUG_TIMER
printf("tmu012_write 0x%lx 0x%08x\n", (unsigned long) offset, value);
#endif
if (offset >= 0x20) {
if (!(s->feat & TMU012_FEAT_3CHAN))
hw_error("tmu012_write: Bad channel offset %x\n", (int)offset);
sh_timer_write(s->timer[2], offset - 0x20, value);
return;
}
if (offset >= 0x14) {
sh_timer_write(s->timer[1], offset - 0x14, value);
return;
}
if (offset >= 0x08) {
sh_timer_write(s->timer[0], offset - 0x08, value);
return;
}
if (offset == 4) {
sh_timer_start_stop(s->timer[0], value & (1 << 0));
sh_timer_start_stop(s->timer[1], value & (1 << 1));
if (s->feat & TMU012_FEAT_3CHAN)
sh_timer_start_stop(s->timer[2], value & (1 << 2));
else
if (value & (1 << 2))
hw_error("tmu012_write: Bad channel\n");
s->tstr = value;
return;
}
if ((s->feat & TMU012_FEAT_TOCR) && offset == 0) {
s->tocr = value & (1 << 0);
}
}
static const MemoryRegionOps tmu012_ops = {
.read = tmu012_read,
.write = tmu012_write,
.endianness = DEVICE_NATIVE_ENDIAN,
};
void tmu012_init(MemoryRegion *sysmem, hwaddr base,
int feat, uint32_t freq,
qemu_irq ch0_irq, qemu_irq ch1_irq,
qemu_irq ch2_irq0, qemu_irq ch2_irq1)
{
tmu012_state *s;
int timer_feat = (feat & TMU012_FEAT_EXTCLK) ? TIMER_FEAT_EXTCLK : 0;
s = (tmu012_state *)g_malloc0(sizeof(tmu012_state));
s->feat = feat;
s->timer[0] = sh_timer_init(freq, timer_feat, ch0_irq);
s->timer[1] = sh_timer_init(freq, timer_feat, ch1_irq);
if (feat & TMU012_FEAT_3CHAN)
s->timer[2] = sh_timer_init(freq, timer_feat | TIMER_FEAT_CAPT,
ch2_irq0); /* ch2_irq1 not supported */
memory_region_init_io(&s->iomem, NULL, &tmu012_ops, s,
"timer", 0x100000000ULL);
memory_region_init_alias(&s->iomem_p4, NULL, "timer-p4",
&s->iomem, 0, 0x1000);
memory_region_add_subregion(sysmem, P4ADDR(base), &s->iomem_p4);
memory_region_init_alias(&s->iomem_a7, NULL, "timer-a7",
&s->iomem, 0, 0x1000);
memory_region_add_subregion(sysmem, A7ADDR(base), &s->iomem_a7);
/* ??? Save/restore. */
}
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