diff options
Diffstat (limited to 'hw/slavio_timer.c')
| -rw-r--r-- | hw/slavio_timer.c | 288 |
1 files changed, 288 insertions, 0 deletions
diff --git a/hw/slavio_timer.c b/hw/slavio_timer.c new file mode 100644 index 0000000..976f0d4 --- /dev/null +++ b/hw/slavio_timer.c @@ -0,0 +1,288 @@ +/* + * 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 { + uint32_t limit, count, counthigh; + int64_t count_load_time; + int64_t expire_time; + int64_t stop_time, tick_offset; + QEMUTimer *irq_timer; + int irq; + int reached, stopped; + int mode; // 0 = processor, 1 = user, 2 = system + unsigned int cpu; +} SLAVIO_TIMERState; + +#define TIMER_MAXADDR 0x1f +#define CNT_FREQ 2000000 + +// Update count, set irq, update expire_time +static void slavio_timer_get_out(SLAVIO_TIMERState *s) +{ + int out; + int64_t diff, ticks, count; + uint32_t limit; + + // There are three clock tick units: CPU ticks, register units + // (nanoseconds), and counter ticks (500 ns). + if (s->mode == 1 && s->stopped) + ticks = s->stop_time; + else + ticks = qemu_get_clock(vm_clock) - s->tick_offset; + + out = (ticks > s->expire_time); + if (out) + s->reached = 0x80000000; + if (!s->limit) + limit = 0x7fffffff; + else + limit = s->limit; + + // Convert register units to counter ticks + limit = limit >> 9; + + // Convert cpu ticks to counter ticks + diff = muldiv64(ticks - s->count_load_time, CNT_FREQ, ticks_per_sec); + + // Calculate what the counter should be, convert to register + // units + count = diff % limit; + s->count = count << 9; + s->counthigh = count >> 22; + + // Expire time: CPU ticks left to next interrupt + // Convert remaining counter ticks to CPU ticks + s->expire_time = ticks + muldiv64(limit - count, ticks_per_sec, CNT_FREQ); + + DPRINTF("irq %d limit %d reached %d d %" PRId64 " count %d s->c %x diff %" PRId64 " stopped %d mode %d\n", s->irq, limit, s->reached?1:0, (ticks-s->count_load_time), count, s->count, s->expire_time - ticks, s->stopped, s->mode); + + if (s->mode != 1) + pic_set_irq_cpu(s->irq, out, s->cpu); +} + +// timer callback +static void slavio_timer_irq(void *opaque) +{ + SLAVIO_TIMERState *s = opaque; + + if (!s->irq_timer) + return; + slavio_timer_get_out(s); + if (s->mode != 1) + qemu_mod_timer(s->irq_timer, s->expire_time); +} + +static uint32_t slavio_timer_mem_readl(void *opaque, target_phys_addr_t addr) +{ + SLAVIO_TIMERState *s = opaque; + uint32_t saddr; + + 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 + pic_set_irq_cpu(s->irq, 0, s->cpu); + s->count_load_time = qemu_get_clock(vm_clock); + s->reached = 0; + return s->limit; + } + else { + slavio_timer_get_out(s); + return s->counthigh & 0x7fffffff; + } + 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) + return (s->count & 0x7fffffff) | s->reached; + else + return s->count; + case 3: + // read start/stop status + return s->stopped; + case 4: + // read user/system mode + return s->mode & 1; + default: + return 0; + } +} + +static void slavio_timer_mem_writel(void *opaque, target_phys_addr_t addr, uint32_t val) +{ + SLAVIO_TIMERState *s = opaque; + uint32_t saddr; + + saddr = (addr & TIMER_MAXADDR) >> 2; + switch (saddr) { + case 0: + // set limit, reset counter + s->count_load_time = qemu_get_clock(vm_clock); + // fall through + case 2: + // set limit without resetting counter + if (!val) + s->limit = 0x7fffffff; + else + s->limit = val & 0x7fffffff; + slavio_timer_irq(s); + break; + case 3: + // start/stop user counter + if (s->mode == 1) { + if (val & 1) { + s->stop_time = qemu_get_clock(vm_clock); + s->stopped = 1; + } + else { + if (s->stopped) + s->tick_offset += qemu_get_clock(vm_clock) - s->stop_time; + 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; + 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_be32s(f, &s->limit); + qemu_put_be32s(f, &s->count); + qemu_put_be32s(f, &s->counthigh); + qemu_put_be64s(f, &s->count_load_time); + qemu_put_be64s(f, &s->expire_time); + qemu_put_be64s(f, &s->stop_time); + qemu_put_be64s(f, &s->tick_offset); + qemu_put_be32s(f, &s->irq); + qemu_put_be32s(f, &s->reached); + qemu_put_be32s(f, &s->stopped); + qemu_put_be32s(f, &s->mode); +} + +static int slavio_timer_load(QEMUFile *f, void *opaque, int version_id) +{ + SLAVIO_TIMERState *s = opaque; + + if (version_id != 1) + return -EINVAL; + + qemu_get_be32s(f, &s->limit); + qemu_get_be32s(f, &s->count); + qemu_get_be32s(f, &s->counthigh); + qemu_get_be64s(f, &s->count_load_time); + qemu_get_be64s(f, &s->expire_time); + qemu_get_be64s(f, &s->stop_time); + qemu_get_be64s(f, &s->tick_offset); + qemu_get_be32s(f, &s->irq); + qemu_get_be32s(f, &s->reached); + qemu_get_be32s(f, &s->stopped); + qemu_get_be32s(f, &s->mode); + return 0; +} + +static void slavio_timer_reset(void *opaque) +{ + SLAVIO_TIMERState *s = opaque; + + s->limit = 0; + s->count = 0; + s->count_load_time = qemu_get_clock(vm_clock);; + s->stop_time = s->count_load_time; + s->tick_offset = 0; + s->reached = 0; + s->mode &= 2; + s->stopped = 1; + slavio_timer_get_out(s); +} + +void slavio_timer_init(uint32_t addr, int irq, int mode, unsigned int cpu) +{ + int slavio_timer_io_memory; + SLAVIO_TIMERState *s; + + s = qemu_mallocz(sizeof(SLAVIO_TIMERState)); + if (!s) + return; + s->irq = irq; + s->mode = mode; + s->cpu = cpu; + s->irq_timer = qemu_new_timer(vm_clock, slavio_timer_irq, s); + + slavio_timer_io_memory = cpu_register_io_memory(0, slavio_timer_mem_read, + slavio_timer_mem_write, s); + cpu_register_physical_memory(addr, TIMER_MAXADDR, slavio_timer_io_memory); + register_savevm("slavio_timer", addr, 1, slavio_timer_save, slavio_timer_load, s); + qemu_register_reset(slavio_timer_reset, s); + slavio_timer_reset(s); +} |