hw/ppc/ppc_booke.c - qemu - Git at Google

 /*
  * QEMU PowerPC Booke hardware System Emulator
  *
  * Copyright (c) 2011 AdaCore
  *
  * 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 "cpu.h"
 #include "hw/ppc/ppc.h"
 #include "qemu/timer.h"
 #include "sysemu/reset.h"
 #include "sysemu/runstate.h"
 #include "qemu/log.h"
 #include "hw/loader.h"
 #include "kvm_ppc.h"


 /* Timer Control Register */

 #define TCR_WP_SHIFT  30        /* Watchdog Timer Period */
 #define TCR_WP_MASK   (0x3U << TCR_WP_SHIFT)
 #define TCR_WRC_SHIFT 28        /* Watchdog Timer Reset Control */
 #define TCR_WRC_MASK  (0x3U << TCR_WRC_SHIFT)
 #define TCR_WIE       (1U << 27) /* Watchdog Timer Interrupt Enable */
 #define TCR_DIE       (1U << 26) /* Decrementer Interrupt Enable */
 #define TCR_FP_SHIFT  24        /* Fixed-Interval Timer Period */
 #define TCR_FP_MASK   (0x3U << TCR_FP_SHIFT)
 #define TCR_FIE       (1U << 23) /* Fixed-Interval Timer Interrupt Enable */
 #define TCR_ARE       (1U << 22) /* Auto-Reload Enable */

 /* Timer Control Register (e500 specific fields) */

 #define TCR_E500_FPEXT_SHIFT 13 /* Fixed-Interval Timer Period Extension */
 #define TCR_E500_FPEXT_MASK  (0xf << TCR_E500_FPEXT_SHIFT)
 #define TCR_E500_WPEXT_SHIFT 17 /* Watchdog Timer Period Extension */
 #define TCR_E500_WPEXT_MASK  (0xf << TCR_E500_WPEXT_SHIFT)

 /* Timer Status Register  */

 #define TSR_FIS       (1U << 26) /* Fixed-Interval Timer Interrupt Status */
 #define TSR_DIS       (1U << 27) /* Decrementer Interrupt Status */
 #define TSR_WRS_SHIFT 28        /* Watchdog Timer Reset Status */
 #define TSR_WRS_MASK  (0x3U << TSR_WRS_SHIFT)
 #define TSR_WIS       (1U << 30) /* Watchdog Timer Interrupt Status */
 #define TSR_ENW       (1U << 31) /* Enable Next Watchdog Timer */

 typedef struct booke_timer_t booke_timer_t;
 struct booke_timer_t {

     uint64_t fit_next;
     QEMUTimer *fit_timer;

     uint64_t wdt_next;
     QEMUTimer *wdt_timer;

     uint32_t flags;
 };

 static void booke_update_irq(PowerPCCPU *cpu)
 {
     CPUPPCState *env = &cpu->env;

     ppc_set_irq(cpu, PPC_INTERRUPT_DECR,
                 (env->spr[SPR_BOOKE_TSR] & TSR_DIS
                  && env->spr[SPR_BOOKE_TCR] & TCR_DIE));

     ppc_set_irq(cpu, PPC_INTERRUPT_WDT,
                 (env->spr[SPR_BOOKE_TSR] & TSR_WIS
                  && env->spr[SPR_BOOKE_TCR] & TCR_WIE));

     ppc_set_irq(cpu, PPC_INTERRUPT_FIT,
                 (env->spr[SPR_BOOKE_TSR] & TSR_FIS
                  && env->spr[SPR_BOOKE_TCR] & TCR_FIE));
 }

 /* Return the location of the bit of time base at which the FIT will raise an
    interrupt */
 static uint8_t booke_get_fit_target(CPUPPCState *env, ppc_tb_t *tb_env)
 {
     uint8_t fp = (env->spr[SPR_BOOKE_TCR] & TCR_FP_MASK) >> TCR_FP_SHIFT;

     if (tb_env->flags & PPC_TIMER_E500) {
         /* e500 Fixed-interval timer period extension */
         uint32_t fpext = (env->spr[SPR_BOOKE_TCR] & TCR_E500_FPEXT_MASK)
             >> TCR_E500_FPEXT_SHIFT;
         fp = 63 - (fp | fpext << 2);
     } else {
         fp = env->fit_period[fp];
     }

     return fp;
 }

 /* Return the location of the bit of time base at which the WDT will raise an
    interrupt */
 static uint8_t booke_get_wdt_target(CPUPPCState *env, ppc_tb_t *tb_env)
 {
     uint8_t wp = (env->spr[SPR_BOOKE_TCR] & TCR_WP_MASK) >> TCR_WP_SHIFT;

     if (tb_env->flags & PPC_TIMER_E500) {
         /* e500 Watchdog timer period extension */
         uint32_t wpext = (env->spr[SPR_BOOKE_TCR] & TCR_E500_WPEXT_MASK)
             >> TCR_E500_WPEXT_SHIFT;
         wp = 63 - (wp | wpext << 2);
     } else {
         wp = env->wdt_period[wp];
     }

     return wp;
 }

 static void booke_update_fixed_timer(CPUPPCState         *env,
                                      uint8_t           target_bit,
                                      uint64_t          *next,
                                      QEMUTimer         *timer,
                                      int               tsr_bit)
 {
     ppc_tb_t *tb_env = env->tb_env;
     uint64_t delta_tick, ticks = 0;
     uint64_t tb;
     uint64_t period;
     uint64_t now;

     if (!(env->spr[SPR_BOOKE_TSR] & tsr_bit)) {
         /*
          * Don't arm the timer again when the guest has the current
          * interrupt still pending. Wait for it to ack it.
          */
         return;
     }

     now = qemu_clock_get_ns(QEMU_CLOCK_VIRTUAL);
     tb  = cpu_ppc_get_tb(tb_env, now, tb_env->tb_offset);
     period = 1ULL << target_bit;
     delta_tick = period - (tb & (period - 1));

     /* the timer triggers only when the selected bit toggles from 0 to 1 */
     if (tb & period) {
         ticks = period;
     }

     if (ticks + delta_tick < ticks) {
         /* Overflow, so assume the biggest number we can express. */
         ticks = UINT64_MAX;
     } else {
         ticks += delta_tick;
     }

     *next = now + muldiv64(ticks, NANOSECONDS_PER_SECOND, tb_env->tb_freq);
     if ((*next < now) || (*next > INT64_MAX)) {
         /* Overflow, so assume the biggest number the qemu timer supports. */
         *next = INT64_MAX;
     }

     /* XXX: If expire time is now. We can't run the callback because we don't
      * have access to it. So we just set the timer one nanosecond later.
      */

     if (*next == now) {
         (*next)++;
     } else {
         /*
          * There's no point to fake any granularity that's more fine grained
          * than milliseconds. Anything beyond that just overloads the system.
          */
         *next = MAX(*next, now + SCALE_MS);
     }

     /* Fire the next timer */
     timer_mod(timer, *next);
 }

 static void booke_decr_cb(void *opaque)
 {
     PowerPCCPU *cpu = opaque;
     CPUPPCState *env = &cpu->env;

     env->spr[SPR_BOOKE_TSR] |= TSR_DIS;
     booke_update_irq(cpu);

     if (env->spr[SPR_BOOKE_TCR] & TCR_ARE) {
         /* Do not reload 0, it is already there. It would just trigger
          * the timer again and lead to infinite loop */
         if (env->spr[SPR_BOOKE_DECAR] != 0) {
             /* Auto Reload */
             cpu_ppc_store_decr(env, env->spr[SPR_BOOKE_DECAR]);
         }
     }
 }

 static void booke_fit_cb(void *opaque)
 {
     PowerPCCPU *cpu = opaque;
     CPUPPCState *env = &cpu->env;
     ppc_tb_t *tb_env;
     booke_timer_t *booke_timer;

     tb_env = env->tb_env;
     booke_timer = tb_env->opaque;
     env->spr[SPR_BOOKE_TSR] |= TSR_FIS;

     booke_update_irq(cpu);

     booke_update_fixed_timer(env,
                              booke_get_fit_target(env, tb_env),
                              &booke_timer->fit_next,
                              booke_timer->fit_timer,
                              TSR_FIS);
 }

 static void booke_wdt_cb(void *opaque)
 {
     PowerPCCPU *cpu = opaque;
     CPUPPCState *env = &cpu->env;
     ppc_tb_t *tb_env;
     booke_timer_t *booke_timer;

     tb_env = env->tb_env;
     booke_timer = tb_env->opaque;

     /* TODO: There's lots of complicated stuff to do here */

     booke_update_irq(cpu);

     booke_update_fixed_timer(env,
                              booke_get_wdt_target(env, tb_env),
                              &booke_timer->wdt_next,
                              booke_timer->wdt_timer,
                              TSR_WIS);
 }

 void store_booke_tsr(CPUPPCState *env, target_ulong val)
 {
     PowerPCCPU *cpu = env_archcpu(env);
     ppc_tb_t *tb_env = env->tb_env;
     booke_timer_t *booke_timer = tb_env->opaque;

     env->spr[SPR_BOOKE_TSR] &= ~val;
     kvmppc_clear_tsr_bits(cpu, val);

     if (val & TSR_FIS) {
         booke_update_fixed_timer(env,
                                  booke_get_fit_target(env, tb_env),
                                  &booke_timer->fit_next,
                                  booke_timer->fit_timer,
                                  TSR_FIS);
     }

     if (val & TSR_WIS) {
         booke_update_fixed_timer(env,
                                  booke_get_wdt_target(env, tb_env),
                                  &booke_timer->wdt_next,
                                  booke_timer->wdt_timer,
                                  TSR_WIS);
     }

     booke_update_irq(cpu);
 }

 void store_booke_tcr(CPUPPCState *env, target_ulong val)
 {
     PowerPCCPU *cpu = env_archcpu(env);
     ppc_tb_t *tb_env = env->tb_env;
     booke_timer_t *booke_timer = tb_env->opaque;

     env->spr[SPR_BOOKE_TCR] = val;
     kvmppc_set_tcr(cpu);

     booke_update_irq(cpu);

     booke_update_fixed_timer(env,
                              booke_get_fit_target(env, tb_env),
                              &booke_timer->fit_next,
                              booke_timer->fit_timer,
                              TSR_FIS);

     booke_update_fixed_timer(env,
                              booke_get_wdt_target(env, tb_env),
                              &booke_timer->wdt_next,
                              booke_timer->wdt_timer,
                              TSR_WIS);
 }

 static void ppc_booke_timer_reset_handle(void *opaque)
 {
     PowerPCCPU *cpu = opaque;
     CPUPPCState *env = &cpu->env;

     store_booke_tcr(env, 0);
     store_booke_tsr(env, -1);
 }

 /*
  * This function will be called whenever the CPU state changes.
  * CPU states are defined "typedef enum RunState".
  * Regarding timer, When CPU state changes to running after debug halt
  * or similar cases which takes time then in between final watchdog
  * expiry happenes. This will cause exit to QEMU and configured watchdog
  * action will be taken. To avoid this we always clear the watchdog state when
  * state changes to running.
  */
 static void cpu_state_change_handler(void *opaque, bool running, RunState state)
 {
     PowerPCCPU *cpu = opaque;
     CPUPPCState *env = &cpu->env;

     if (!running) {
         return;
     }

     /*
      * Clear watchdog interrupt condition by clearing TSR.
      */
     store_booke_tsr(env, TSR_ENW | TSR_WIS | TSR_WRS_MASK);
 }

 void ppc_booke_timers_init(PowerPCCPU *cpu, uint32_t freq, uint32_t flags)
 {
     ppc_tb_t *tb_env;
     booke_timer_t *booke_timer;
     int ret = 0;

     tb_env      = g_malloc0(sizeof(ppc_tb_t));
     booke_timer = g_malloc0(sizeof(booke_timer_t));

     cpu->env.tb_env = tb_env;
     tb_env->flags = flags | PPC_TIMER_BOOKE | PPC_DECR_ZERO_TRIGGERED;

     tb_env->tb_freq    = freq;
     tb_env->decr_freq  = freq;
     tb_env->opaque     = booke_timer;
     tb_env->decr_timer = timer_new_ns(QEMU_CLOCK_VIRTUAL, &booke_decr_cb, cpu);

     booke_timer->fit_timer =
         timer_new_ns(QEMU_CLOCK_VIRTUAL, &booke_fit_cb, cpu);
     booke_timer->wdt_timer =
         timer_new_ns(QEMU_CLOCK_VIRTUAL, &booke_wdt_cb, cpu);

     ret = kvmppc_booke_watchdog_enable(cpu);

     if (ret) {
         /* TODO: Start the QEMU emulated watchdog if not running on KVM.
          * Also start the QEMU emulated watchdog if KVM does not support
          * emulated watchdog or somehow it is not enabled (supported but
          * not enabled is though some bug and requires debugging :)).
          */
     }

     qemu_add_vm_change_state_handler(cpu_state_change_handler, cpu);

     qemu_register_reset(ppc_booke_timer_reset_handle, cpu);
 }
	/*
	* QEMU PowerPC Booke hardware System Emulator
	*
	* Copyright (c) 2011 AdaCore
	*
	* 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 "cpu.h"
	#include "hw/ppc/ppc.h"
	#include "qemu/timer.h"
	#include "sysemu/reset.h"
	#include "sysemu/runstate.h"
	#include "qemu/log.h"
	#include "hw/loader.h"
	#include "kvm_ppc.h"


	/* Timer Control Register */

	#define TCR_WP_SHIFT 30 /* Watchdog Timer Period */
	#define TCR_WP_MASK (0x3U << TCR_WP_SHIFT)
	#define TCR_WRC_SHIFT 28 /* Watchdog Timer Reset Control */
	#define TCR_WRC_MASK (0x3U << TCR_WRC_SHIFT)
	#define TCR_WIE (1U << 27) /* Watchdog Timer Interrupt Enable */
	#define TCR_DIE (1U << 26) /* Decrementer Interrupt Enable */
	#define TCR_FP_SHIFT 24 /* Fixed-Interval Timer Period */
	#define TCR_FP_MASK (0x3U << TCR_FP_SHIFT)
	#define TCR_FIE (1U << 23) /* Fixed-Interval Timer Interrupt Enable */
	#define TCR_ARE (1U << 22) /* Auto-Reload Enable */

	/* Timer Control Register (e500 specific fields) */

	#define TCR_E500_FPEXT_SHIFT 13 /* Fixed-Interval Timer Period Extension */
	#define TCR_E500_FPEXT_MASK (0xf << TCR_E500_FPEXT_SHIFT)
	#define TCR_E500_WPEXT_SHIFT 17 /* Watchdog Timer Period Extension */
	#define TCR_E500_WPEXT_MASK (0xf << TCR_E500_WPEXT_SHIFT)

	/* Timer Status Register */

	#define TSR_FIS (1U << 26) /* Fixed-Interval Timer Interrupt Status */
	#define TSR_DIS (1U << 27) /* Decrementer Interrupt Status */
	#define TSR_WRS_SHIFT 28 /* Watchdog Timer Reset Status */
	#define TSR_WRS_MASK (0x3U << TSR_WRS_SHIFT)
	#define TSR_WIS (1U << 30) /* Watchdog Timer Interrupt Status */
	#define TSR_ENW (1U << 31) /* Enable Next Watchdog Timer */

	typedef struct booke_timer_t booke_timer_t;
	struct booke_timer_t {

	uint64_t fit_next;
	QEMUTimer *fit_timer;

	uint64_t wdt_next;
	QEMUTimer *wdt_timer;

	uint32_t flags;
	};

	static void booke_update_irq(PowerPCCPU *cpu)
	{
	CPUPPCState *env = &cpu->env;

	ppc_set_irq(cpu, PPC_INTERRUPT_DECR,
	(env->spr[SPR_BOOKE_TSR] & TSR_DIS
	&& env->spr[SPR_BOOKE_TCR] & TCR_DIE));

	ppc_set_irq(cpu, PPC_INTERRUPT_WDT,
	(env->spr[SPR_BOOKE_TSR] & TSR_WIS
	&& env->spr[SPR_BOOKE_TCR] & TCR_WIE));

	ppc_set_irq(cpu, PPC_INTERRUPT_FIT,
	(env->spr[SPR_BOOKE_TSR] & TSR_FIS
	&& env->spr[SPR_BOOKE_TCR] & TCR_FIE));
	}

	/* Return the location of the bit of time base at which the FIT will raise an
	interrupt */
	static uint8_t booke_get_fit_target(CPUPPCState env, ppc_tb_t tb_env)
	{
	uint8_t fp = (env->spr[SPR_BOOKE_TCR] & TCR_FP_MASK) >> TCR_FP_SHIFT;

	if (tb_env->flags & PPC_TIMER_E500) {
	/* e500 Fixed-interval timer period extension */
	uint32_t fpext = (env->spr[SPR_BOOKE_TCR] & TCR_E500_FPEXT_MASK)
	>> TCR_E500_FPEXT_SHIFT;
	fp = 63 - (fp \| fpext << 2);
	} else {
	fp = env->fit_period[fp];
	}

	return fp;
	}

	/* Return the location of the bit of time base at which the WDT will raise an
	interrupt */
	static uint8_t booke_get_wdt_target(CPUPPCState env, ppc_tb_t tb_env)
	{
	uint8_t wp = (env->spr[SPR_BOOKE_TCR] & TCR_WP_MASK) >> TCR_WP_SHIFT;

	if (tb_env->flags & PPC_TIMER_E500) {
	/* e500 Watchdog timer period extension */
	uint32_t wpext = (env->spr[SPR_BOOKE_TCR] & TCR_E500_WPEXT_MASK)
	>> TCR_E500_WPEXT_SHIFT;
	wp = 63 - (wp \| wpext << 2);
	} else {
	wp = env->wdt_period[wp];
	}

	return wp;
	}

	static void booke_update_fixed_timer(CPUPPCState *env,
	uint8_t target_bit,
	uint64_t *next,
	QEMUTimer *timer,
	int tsr_bit)
	{
	ppc_tb_t *tb_env = env->tb_env;
	uint64_t delta_tick, ticks = 0;
	uint64_t tb;
	uint64_t period;
	uint64_t now;

	if (!(env->spr[SPR_BOOKE_TSR] & tsr_bit)) {
	/*
	* Don't arm the timer again when the guest has the current
	* interrupt still pending. Wait for it to ack it.
	*/
	return;
	}

	now = qemu_clock_get_ns(QEMU_CLOCK_VIRTUAL);
	tb = cpu_ppc_get_tb(tb_env, now, tb_env->tb_offset);
	period = 1ULL << target_bit;
	delta_tick = period - (tb & (period - 1));

	/* the timer triggers only when the selected bit toggles from 0 to 1 */
	if (tb & period) {
	ticks = period;
	}

	if (ticks + delta_tick < ticks) {
	/* Overflow, so assume the biggest number we can express. */
	ticks = UINT64_MAX;
	} else {
	ticks += delta_tick;
	}

	*next = now + muldiv64(ticks, NANOSECONDS_PER_SECOND, tb_env->tb_freq);
	if ((next < now) \|\| (next > INT64_MAX)) {
	/* Overflow, so assume the biggest number the qemu timer supports. */
	*next = INT64_MAX;
	}

	/* XXX: If expire time is now. We can't run the callback because we don't
	* have access to it. So we just set the timer one nanosecond later.
	*/

	if (*next == now) {
	(*next)++;
	} else {
	/*
	* There's no point to fake any granularity that's more fine grained
	* than milliseconds. Anything beyond that just overloads the system.
	*/
	next = MAX(next, now + SCALE_MS);
	}

	/* Fire the next timer */
	timer_mod(timer, *next);
	}

	static void booke_decr_cb(void *opaque)
	{
	PowerPCCPU *cpu = opaque;
	CPUPPCState *env = &cpu->env;

	env->spr[SPR_BOOKE_TSR] \|= TSR_DIS;
	booke_update_irq(cpu);

	if (env->spr[SPR_BOOKE_TCR] & TCR_ARE) {
	/* Do not reload 0, it is already there. It would just trigger
	* the timer again and lead to infinite loop */
	if (env->spr[SPR_BOOKE_DECAR] != 0) {
	/* Auto Reload */
	cpu_ppc_store_decr(env, env->spr[SPR_BOOKE_DECAR]);
	}
	}
	}

	static void booke_fit_cb(void *opaque)
	{
	PowerPCCPU *cpu = opaque;
	CPUPPCState *env = &cpu->env;
	ppc_tb_t *tb_env;
	booke_timer_t *booke_timer;

	tb_env = env->tb_env;
	booke_timer = tb_env->opaque;
	env->spr[SPR_BOOKE_TSR] \|= TSR_FIS;

	booke_update_irq(cpu);

	booke_update_fixed_timer(env,
	booke_get_fit_target(env, tb_env),
	&booke_timer->fit_next,
	booke_timer->fit_timer,
	TSR_FIS);
	}

	static void booke_wdt_cb(void *opaque)
	{
	PowerPCCPU *cpu = opaque;
	CPUPPCState *env = &cpu->env;
	ppc_tb_t *tb_env;
	booke_timer_t *booke_timer;

	tb_env = env->tb_env;
	booke_timer = tb_env->opaque;

	/* TODO: There's lots of complicated stuff to do here */

	booke_update_irq(cpu);

	booke_update_fixed_timer(env,
	booke_get_wdt_target(env, tb_env),
	&booke_timer->wdt_next,
	booke_timer->wdt_timer,
	TSR_WIS);
	}

	void store_booke_tsr(CPUPPCState *env, target_ulong val)
	{
	PowerPCCPU *cpu = env_archcpu(env);
	ppc_tb_t *tb_env = env->tb_env;
	booke_timer_t *booke_timer = tb_env->opaque;

	env->spr[SPR_BOOKE_TSR] &= ~val;
	kvmppc_clear_tsr_bits(cpu, val);

	if (val & TSR_FIS) {
	booke_update_fixed_timer(env,
	booke_get_fit_target(env, tb_env),
	&booke_timer->fit_next,
	booke_timer->fit_timer,
	TSR_FIS);
	}

	if (val & TSR_WIS) {
	booke_update_fixed_timer(env,
	booke_get_wdt_target(env, tb_env),
	&booke_timer->wdt_next,
	booke_timer->wdt_timer,
	TSR_WIS);
	}

	booke_update_irq(cpu);
	}

	void store_booke_tcr(CPUPPCState *env, target_ulong val)
	{
	PowerPCCPU *cpu = env_archcpu(env);
	ppc_tb_t *tb_env = env->tb_env;
	booke_timer_t *booke_timer = tb_env->opaque;

	env->spr[SPR_BOOKE_TCR] = val;
	kvmppc_set_tcr(cpu);

	booke_update_irq(cpu);

	booke_update_fixed_timer(env,
	booke_get_fit_target(env, tb_env),
	&booke_timer->fit_next,
	booke_timer->fit_timer,
	TSR_FIS);

	booke_update_fixed_timer(env,
	booke_get_wdt_target(env, tb_env),
	&booke_timer->wdt_next,
	booke_timer->wdt_timer,
	TSR_WIS);
	}

	static void ppc_booke_timer_reset_handle(void *opaque)
	{
	PowerPCCPU *cpu = opaque;
	CPUPPCState *env = &cpu->env;

	store_booke_tcr(env, 0);
	store_booke_tsr(env, -1);
	}

	/*
	* This function will be called whenever the CPU state changes.
	* CPU states are defined "typedef enum RunState".
	* Regarding timer, When CPU state changes to running after debug halt
	* or similar cases which takes time then in between final watchdog
	* expiry happenes. This will cause exit to QEMU and configured watchdog
	* action will be taken. To avoid this we always clear the watchdog state when
	* state changes to running.
	*/
	static void cpu_state_change_handler(void *opaque, bool running, RunState state)
	{
	PowerPCCPU *cpu = opaque;
	CPUPPCState *env = &cpu->env;

	if (!running) {
	return;
	}

	/*
	* Clear watchdog interrupt condition by clearing TSR.
	*/
	store_booke_tsr(env, TSR_ENW \| TSR_WIS \| TSR_WRS_MASK);
	}

	void ppc_booke_timers_init(PowerPCCPU *cpu, uint32_t freq, uint32_t flags)
	{
	ppc_tb_t *tb_env;
	booke_timer_t *booke_timer;
	int ret = 0;

	tb_env = g_malloc0(sizeof(ppc_tb_t));
	booke_timer = g_malloc0(sizeof(booke_timer_t));

	cpu->env.tb_env = tb_env;
	tb_env->flags = flags \| PPC_TIMER_BOOKE \| PPC_DECR_ZERO_TRIGGERED;

	tb_env->tb_freq = freq;
	tb_env->decr_freq = freq;
	tb_env->opaque = booke_timer;
	tb_env->decr_timer = timer_new_ns(QEMU_CLOCK_VIRTUAL, &booke_decr_cb, cpu);

	booke_timer->fit_timer =
	timer_new_ns(QEMU_CLOCK_VIRTUAL, &booke_fit_cb, cpu);
	booke_timer->wdt_timer =
	timer_new_ns(QEMU_CLOCK_VIRTUAL, &booke_wdt_cb, cpu);

	ret = kvmppc_booke_watchdog_enable(cpu);

	if (ret) {
	/* TODO: Start the QEMU emulated watchdog if not running on KVM.
	* Also start the QEMU emulated watchdog if KVM does not support
	* emulated watchdog or somehow it is not enabled (supported but
	* not enabled is though some bug and requires debugging :)).
	*/
	}

	qemu_add_vm_change_state_handler(cpu_state_change_handler, cpu);

	qemu_register_reset(ppc_booke_timer_reset_handle, cpu);
	}