qemu-e2k/hw/slavio_timer.c

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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 "vl.h"
//#define DEBUG_TIMER
#ifdef DEBUG_TIMER
#define DPRINTF(fmt, args...) \
do { printf("TIMER: " fmt , ##args); } while (0)
#else
#define DPRINTF(fmt, args...)
#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.
*
*/
typedef struct SLAVIO_TIMERState {
qemu_irq irq;
ptimer_state *timer;
uint32_t count, counthigh, reached;
uint64_t limit;
int stopped;
int mode; // 0 = processor, 1 = user, 2 = system
} SLAVIO_TIMERState;
#define TIMER_MAXADDR 0x1f
#define TIMER_SIZE (TIMER_MAXADDR + 1)
// Update count, set irq, update expire_time
// Convert from ptimer countdown units
static void slavio_timer_get_out(SLAVIO_TIMERState *s)
{
uint64_t count;
count = s->limit - (ptimer_get_count(s->timer) << 9);
DPRINTF("get_out: limit %" PRIx64 " count %x%08x\n", s->limit, s->counthigh,
s->count);
s->count = count & 0xfffffe00;
s->counthigh = count >> 32;
}
// timer callback
static void slavio_timer_irq(void *opaque)
{
SLAVIO_TIMERState *s = opaque;
slavio_timer_get_out(s);
DPRINTF("callback: count %x%08x\n", s->counthigh, s->count);
s->reached = 0x80000000;
if (s->mode != 1)
qemu_irq_raise(s->irq);
}
static uint32_t slavio_timer_mem_readl(void *opaque, target_phys_addr_t addr)
{
SLAVIO_TIMERState *s = opaque;
uint32_t saddr, ret;
saddr = (addr & TIMER_MAXADDR) >> 2;
switch (saddr) {
case 0:
// read limit (system counter mode) or read most signifying
// part of counter (user mode)
if (s->mode != 1) {
// clear irq
qemu_irq_lower(s->irq);
s->reached = 0;
ret = s->limit & 0x7fffffff;
}
else {
slavio_timer_get_out(s);
ret = s->counthigh & 0x7fffffff;
}
break;
case 1:
// read counter and reached bit (system mode) or read lsbits
// of counter (user mode)
slavio_timer_get_out(s);
if (s->mode != 1)
ret = (s->count & 0x7fffffff) | s->reached;
else
ret = s->count;
break;
case 3:
// read start/stop status
ret = s->stopped;
break;
case 4:
// read user/system mode
ret = s->mode & 1;
break;
default:
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)
{
SLAVIO_TIMERState *s = opaque;
uint32_t saddr;
int reload = 0;
DPRINTF("write " TARGET_FMT_plx " %08x\n", addr, val);
saddr = (addr & TIMER_MAXADDR) >> 2;
switch (saddr) {
case 0:
// set limit, reset counter
reload = 1;
qemu_irq_lower(s->irq);
// fall through
case 2:
// set limit without resetting counter
s->limit = val & 0x7ffffe00ULL;
if (!s->limit)
s->limit = 0x7ffffe00ULL;
ptimer_set_limit(s->timer, s->limit >> 9, reload);
break;
case 3:
// start/stop user counter
if (s->mode == 1) {
if (val & 1) {
ptimer_stop(s->timer);
s->stopped = 1;
}
else {
ptimer_run(s->timer, 0);
s->stopped = 0;
}
}
break;
case 4:
// bit 0: user (1) or system (0) counter mode
if (s->mode == 0 || s->mode == 1)
s->mode = val & 1;
if (s->mode == 1) {
qemu_irq_lower(s->irq);
s->limit = -1ULL;
}
ptimer_set_limit(s->timer, s->limit >> 9, 1);
break;
default:
break;
}
}
static CPUReadMemoryFunc *slavio_timer_mem_read[3] = {
slavio_timer_mem_readl,
slavio_timer_mem_readl,
slavio_timer_mem_readl,
};
static CPUWriteMemoryFunc *slavio_timer_mem_write[3] = {
slavio_timer_mem_writel,
slavio_timer_mem_writel,
slavio_timer_mem_writel,
};
static void slavio_timer_save(QEMUFile *f, void *opaque)
{
SLAVIO_TIMERState *s = opaque;
qemu_put_be64s(f, &s->limit);
qemu_put_be32s(f, &s->count);
qemu_put_be32s(f, &s->counthigh);
qemu_put_be32(f, 0); // Was irq
qemu_put_be32s(f, &s->reached);
qemu_put_be32s(f, &s->stopped);
qemu_put_be32s(f, &s->mode);
qemu_put_ptimer(f, s->timer);
}
static int slavio_timer_load(QEMUFile *f, void *opaque, int version_id)
{
SLAVIO_TIMERState *s = opaque;
uint32_t tmp;
if (version_id != 2)
return -EINVAL;
qemu_get_be64s(f, &s->limit);
qemu_get_be32s(f, &s->count);
qemu_get_be32s(f, &s->counthigh);
qemu_get_be32s(f, &tmp); // Was irq
qemu_get_be32s(f, &s->reached);
qemu_get_be32s(f, &s->stopped);
qemu_get_be32s(f, &s->mode);
qemu_get_ptimer(f, s->timer);
return 0;
}
static void slavio_timer_reset(void *opaque)
{
SLAVIO_TIMERState *s = opaque;
s->limit = 0x7ffffe00ULL;
s->count = 0;
s->reached = 0;
s->mode &= 2;
ptimer_set_limit(s->timer, s->limit >> 9, 1);
ptimer_run(s->timer, 0);
s->stopped = 1;
qemu_irq_lower(s->irq);
}
void slavio_timer_init(target_phys_addr_t addr, qemu_irq irq, int mode)
{
int slavio_timer_io_memory;
SLAVIO_TIMERState *s;
QEMUBH *bh;
s = qemu_mallocz(sizeof(SLAVIO_TIMERState));
if (!s)
return;
s->irq = irq;
s->mode = mode;
bh = qemu_bh_new(slavio_timer_irq, s);
s->timer = ptimer_init(bh);
ptimer_set_period(s->timer, 500ULL);
slavio_timer_io_memory = cpu_register_io_memory(0, slavio_timer_mem_read,
slavio_timer_mem_write, s);
cpu_register_physical_memory(addr, TIMER_SIZE, slavio_timer_io_memory);
register_savevm("slavio_timer", addr, 2, slavio_timer_save, slavio_timer_load, s);
qemu_register_reset(slavio_timer_reset, s);
slavio_timer_reset(s);
}