hw/slavio_timer.c - qemu - Git at Google

 /*
  * 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);
 }
	/*
	* 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);
	}