qemu-e2k/include/qemu/timer.h

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#ifndef QEMU_TIMER_H
#define QEMU_TIMER_H
#include "qemu/typedefs.h"
#include "qemu-common.h"
#include "qemu/notify.h"
/* timers */
#define SCALE_MS 1000000
#define SCALE_US 1000
#define SCALE_NS 1
/**
* QEMUClockType:
*
* The following clock types are available:
*
* @QEMU_CLOCK_REALTIME: Real time clock
*
* The real time clock should be used only for stuff which does not
* change the virtual machine state, as it is run even if the virtual
* machine is stopped. The real time clock has a frequency of 1000
* Hz.
*
* @QEMU_CLOCK_VIRTUAL: virtual clock
*
* The virtual clock is only run during the emulation. It is stopped
* when the virtual machine is stopped. Virtual timers use a high
* precision clock, usually cpu cycles (use ticks_per_sec).
*
* @QEMU_CLOCK_HOST: host clock
*
* The host clock should be use for device models that emulate accurate
* real time sources. It will continue to run when the virtual machine
* is suspended, and it will reflect system time changes the host may
* undergo (e.g. due to NTP). The host clock has the same precision as
* the virtual clock.
*
* @QEMU_CLOCK_VIRTUAL_RT: realtime clock used for icount warp
*
* Outside icount mode, this clock is the same as @QEMU_CLOCK_VIRTUAL.
* In icount mode, this clock counts nanoseconds while the virtual
* machine is running. It is used to increase @QEMU_CLOCK_VIRTUAL
* while the CPUs are sleeping and thus not executing instructions.
*/
typedef enum {
QEMU_CLOCK_REALTIME = 0,
QEMU_CLOCK_VIRTUAL = 1,
QEMU_CLOCK_HOST = 2,
QEMU_CLOCK_VIRTUAL_RT = 3,
QEMU_CLOCK_MAX
} QEMUClockType;
typedef struct QEMUTimerList QEMUTimerList;
struct QEMUTimerListGroup {
QEMUTimerList *tl[QEMU_CLOCK_MAX];
};
typedef void QEMUTimerCB(void *opaque);
typedef void QEMUTimerListNotifyCB(void *opaque);
struct QEMUTimer {
int64_t expire_time; /* in nanoseconds */
QEMUTimerList *timer_list;
QEMUTimerCB *cb;
void *opaque;
QEMUTimer *next;
int scale;
};
extern QEMUTimerListGroup main_loop_tlg;
/*
* QEMUClockType
*/
/*
* qemu_clock_get_ns;
* @type: the clock type
*
* Get the nanosecond value of a clock with
* type @type
*
* Returns: the clock value in nanoseconds
*/
int64_t qemu_clock_get_ns(QEMUClockType type);
/**
* qemu_clock_get_ms;
* @type: the clock type
*
* Get the millisecond value of a clock with
* type @type
*
* Returns: the clock value in milliseconds
*/
static inline int64_t qemu_clock_get_ms(QEMUClockType type)
{
return qemu_clock_get_ns(type) / SCALE_MS;
}
/**
* qemu_clock_get_us;
* @type: the clock type
*
* Get the microsecond value of a clock with
* type @type
*
* Returns: the clock value in microseconds
*/
static inline int64_t qemu_clock_get_us(QEMUClockType type)
{
return qemu_clock_get_ns(type) / SCALE_US;
}
/**
* qemu_clock_has_timers:
* @type: the clock type
*
* Determines whether a clock's default timer list
* has timers attached
*
* Note that this function should not be used when other threads also access
* the timer list. The return value may be outdated by the time it is acted
* upon.
*
* Returns: true if the clock's default timer list
* has timers attached
*/
bool qemu_clock_has_timers(QEMUClockType type);
/**
* qemu_clock_expired:
* @type: the clock type
*
* Determines whether a clock's default timer list
* has an expired clock.
*
* Returns: true if the clock's default timer list has
* an expired timer
*/
bool qemu_clock_expired(QEMUClockType type);
/**
* qemu_clock_use_for_deadline:
* @type: the clock type
*
* Determine whether a clock should be used for deadline
* calculations. Some clocks, for instance vm_clock with
* use_icount set, do not count in nanoseconds. Such clocks
* are not used for deadline calculations, and are presumed
* to interrupt any poll using qemu_notify/aio_notify
* etc.
*
* Returns: true if the clock runs in nanoseconds and
* should be used for a deadline.
*/
bool qemu_clock_use_for_deadline(QEMUClockType type);
/**
* qemu_clock_deadline_ns_all:
* @type: the clock type
*
* Calculate the deadline across all timer lists associated
* with a clock (as opposed to just the default one)
* in nanoseconds, or -1 if no timer is set to expire.
*
* Returns: time until expiry in nanoseconds or -1
*/
int64_t qemu_clock_deadline_ns_all(QEMUClockType type);
/**
* qemu_clock_get_main_loop_timerlist:
* @type: the clock type
*
* Return the default timer list assocatiated with a clock.
*
* Returns: the default timer list
*/
QEMUTimerList *qemu_clock_get_main_loop_timerlist(QEMUClockType type);
/**
* qemu_clock_nofify:
* @type: the clock type
*
* Call the notifier callback connected with the default timer
* list linked to the clock, or qemu_notify() if none.
*/
void qemu_clock_notify(QEMUClockType type);
/**
* qemu_clock_enable:
* @type: the clock type
* @enabled: true to enable, false to disable
*
* Enable or disable a clock
* Disabling the clock will wait for related timerlists to stop
* executing qemu_run_timers. Thus, this functions should not
* be used from the callback of a timer that is based on @clock.
* Doing so would cause a deadlock.
*
* Caller should hold BQL.
*/
void qemu_clock_enable(QEMUClockType type, bool enabled);
/**
* qemu_clock_warp:
* @type: the clock type
*
* Warp a clock to a new value
*/
void qemu_clock_warp(QEMUClockType type);
/**
* qemu_clock_register_reset_notifier:
* @type: the clock type
* @notifier: the notifier function
*
* Register a notifier function to call when the clock
* concerned is reset.
*/
void qemu_clock_register_reset_notifier(QEMUClockType type,
Notifier *notifier);
/**
* qemu_clock_unregister_reset_notifier:
* @type: the clock type
* @notifier: the notifier function
*
* Unregister a notifier function to call when the clock
* concerned is reset.
*/
void qemu_clock_unregister_reset_notifier(QEMUClockType type,
Notifier *notifier);
/**
* qemu_clock_run_timers:
* @type: clock on which to operate
*
* Run all the timers associated with the default timer list
* of a clock.
*
* Returns: true if any timer ran.
*/
bool qemu_clock_run_timers(QEMUClockType type);
/**
* qemu_clock_run_all_timers:
*
* Run all the timers associated with the default timer list
* of every clock.
*
* Returns: true if any timer ran.
*/
bool qemu_clock_run_all_timers(void);
/*
* QEMUTimerList
*/
/**
* timerlist_new:
* @type: the clock type to associate with the timerlist
* @cb: the callback to call on notification
* @opaque: the opaque pointer to pass to the callback
*
* Create a new timerlist associated with the clock of
* type @type.
*
* Returns: a pointer to the QEMUTimerList created
*/
QEMUTimerList *timerlist_new(QEMUClockType type,
QEMUTimerListNotifyCB *cb, void *opaque);
/**
* timerlist_free:
* @timer_list: the timer list to free
*
* Frees a timer_list. It must have no active timers.
*/
void timerlist_free(QEMUTimerList *timer_list);
/**
* timerlist_has_timers:
* @timer_list: the timer list to operate on
*
* Determine whether a timer list has active timers
*
* Note that this function should not be used when other threads also access
* the timer list. The return value may be outdated by the time it is acted
* upon.
*
* Returns: true if the timer list has timers.
*/
bool timerlist_has_timers(QEMUTimerList *timer_list);
/**
* timerlist_expired:
* @timer_list: the timer list to operate on
*
* Determine whether a timer list has any timers which
* are expired.
*
* Returns: true if the timer list has timers which
* have expired.
*/
bool timerlist_expired(QEMUTimerList *timer_list);
/**
* timerlist_deadline_ns:
* @timer_list: the timer list to operate on
*
* Determine the deadline for a timer_list, i.e.
* the number of nanoseconds until the first timer
* expires. Return -1 if there are no timers.
*
* Returns: the number of nanoseconds until the earliest
* timer expires -1 if none
*/
int64_t timerlist_deadline_ns(QEMUTimerList *timer_list);
/**
* timerlist_get_clock:
* @timer_list: the timer list to operate on
*
* Determine the clock type associated with a timer list.
*
* Returns: the clock type associated with the
* timer list.
*/
QEMUClockType timerlist_get_clock(QEMUTimerList *timer_list);
/**
* timerlist_run_timers:
* @timer_list: the timer list to use
*
* Call all expired timers associated with the timer list.
*
* Returns: true if any timer expired
*/
bool timerlist_run_timers(QEMUTimerList *timer_list);
/**
* timerlist_notify:
* @timer_list: the timer list to use
*
* call the notifier callback associated with the timer list.
*/
void timerlist_notify(QEMUTimerList *timer_list);
/*
* QEMUTimerListGroup
*/
/**
* timerlistgroup_init:
* @tlg: the timer list group
* @cb: the callback to call when a notify is required
* @opaque: the opaque pointer to be passed to the callback.
*
* Initialise a timer list group. This must already be
* allocated in memory and zeroed. The notifier callback is
* called whenever a clock in the timer list group is
* reenabled or whenever a timer associated with any timer
* list is modified. If @cb is specified as null, qemu_notify()
* is used instead.
*/
void timerlistgroup_init(QEMUTimerListGroup *tlg,
QEMUTimerListNotifyCB *cb, void *opaque);
/**
* timerlistgroup_deinit:
* @tlg: the timer list group
*
* Deinitialise a timer list group. This must already be
* initialised. Note the memory is not freed.
*/
void timerlistgroup_deinit(QEMUTimerListGroup *tlg);
/**
* timerlistgroup_run_timers:
* @tlg: the timer list group
*
* Run the timers associated with a timer list group.
* This will run timers on multiple clocks.
*
* Returns: true if any timer callback ran
*/
bool timerlistgroup_run_timers(QEMUTimerListGroup *tlg);
/**
* timerlistgroup_deadline_ns:
* @tlg: the timer list group
*
* Determine the deadline of the soonest timer to
* expire associated with any timer list linked to
* the timer list group. Only clocks suitable for
* deadline calculation are included.
*
* Returns: the deadline in nanoseconds or -1 if no
* timers are to expire.
*/
int64_t timerlistgroup_deadline_ns(QEMUTimerListGroup *tlg);
/*
* QEMUTimer
*/
/**
* timer_init_tl:
* @ts: the timer to be initialised
* @timer_list: the timer list to attach the timer to
* @scale: the scale value for the timer
* @cb: the callback to be called when the timer expires
* @opaque: the opaque pointer to be passed to the callback
*
* Initialise a new timer and associate it with @timer_list.
* The caller is responsible for allocating the memory.
*
* You need not call an explicit deinit call. Simply make
* sure it is not on a list with timer_del.
*/
void timer_init_tl(QEMUTimer *ts,
QEMUTimerList *timer_list, int scale,
QEMUTimerCB *cb, void *opaque);
/**
* timer_new_tl:
* @timer_list: the timer list to attach the timer to
* @scale: the scale value for the timer
* @cb: the callback to be called when the timer expires
* @opaque: the opaque pointer to be passed to the callback
*
* Creeate a new timer and associate it with @timer_list.
* The memory is allocated by the function.
*
* This is not the preferred interface unless you know you
* are going to call timer_free. Use timer_init instead.
*
* Returns: a pointer to the timer
*/
static inline QEMUTimer *timer_new_tl(QEMUTimerList *timer_list,
int scale,
QEMUTimerCB *cb,
void *opaque)
{
QEMUTimer *ts = g_malloc0(sizeof(QEMUTimer));
timer_init_tl(ts, timer_list, scale, cb, opaque);
return ts;
}
/**
* timer_new:
* @type: the clock type to use
* @scale: the scale value for the timer
* @cb: the callback to be called when the timer expires
* @opaque: the opaque pointer to be passed to the callback
*
* Creeate a new timer and associate it with the default
* timer list for the clock type @type.
*
* Returns: a pointer to the timer
*/
static inline QEMUTimer *timer_new(QEMUClockType type, int scale,
QEMUTimerCB *cb, void *opaque)
{
return timer_new_tl(main_loop_tlg.tl[type], scale, cb, opaque);
}
/**
* timer_new_ns:
* @clock: the clock to associate with the timer
* @callback: the callback to call when the timer expires
* @opaque: the opaque pointer to pass to the callback
*
* Create a new timer with nanosecond scale on the default timer list
* associated with the clock.
*
* Returns: a pointer to the newly created timer
*/
static inline QEMUTimer *timer_new_ns(QEMUClockType type, QEMUTimerCB *cb,
void *opaque)
{
return timer_new(type, SCALE_NS, cb, opaque);
}
/**
* timer_new_us:
* @clock: the clock to associate with the timer
* @callback: the callback to call when the timer expires
* @opaque: the opaque pointer to pass to the callback
*
* Create a new timer with microsecond scale on the default timer list
* associated with the clock.
*
* Returns: a pointer to the newly created timer
*/
static inline QEMUTimer *timer_new_us(QEMUClockType type, QEMUTimerCB *cb,
void *opaque)
{
return timer_new(type, SCALE_US, cb, opaque);
}
/**
* timer_new_ms:
* @clock: the clock to associate with the timer
* @callback: the callback to call when the timer expires
* @opaque: the opaque pointer to pass to the callback
*
* Create a new timer with millisecond scale on the default timer list
* associated with the clock.
*
* Returns: a pointer to the newly created timer
*/
static inline QEMUTimer *timer_new_ms(QEMUClockType type, QEMUTimerCB *cb,
void *opaque)
{
return timer_new(type, SCALE_MS, cb, opaque);
}
/**
* timer_free:
* @ts: the timer
*
* Free a timer (it must not be on the active list)
*/
void timer_free(QEMUTimer *ts);
/**
* timer_del:
* @ts: the timer
*
* Delete a timer from the active list.
*
* This function is thread-safe but the timer and its timer list must not be
* freed while this function is running.
*/
void timer_del(QEMUTimer *ts);
/**
* timer_mod_ns:
* @ts: the timer
* @expire_time: the expiry time in nanoseconds
*
* Modify a timer to expire at @expire_time
*
* This function is thread-safe but the timer and its timer list must not be
* freed while this function is running.
*/
void timer_mod_ns(QEMUTimer *ts, int64_t expire_time);
/**
* timer_mod_anticipate_ns:
* @ts: the timer
* @expire_time: the expiry time in nanoseconds
*
* Modify a timer to expire at @expire_time or the current time,
* whichever comes earlier.
*
* This function is thread-safe but the timer and its timer list must not be
* freed while this function is running.
*/
void timer_mod_anticipate_ns(QEMUTimer *ts, int64_t expire_time);
/**
* timer_mod:
* @ts: the timer
* @expire_time: the expire time in the units associated with the timer
*
* Modify a timer to expiry at @expire_time, taking into
* account the scale associated with the timer.
*
* This function is thread-safe but the timer and its timer list must not be
* freed while this function is running.
*/
void timer_mod(QEMUTimer *ts, int64_t expire_timer);
/**
* timer_mod_anticipate:
* @ts: the timer
* @expire_time: the expiry time in nanoseconds
*
* Modify a timer to expire at @expire_time or the current time, whichever
* comes earlier, taking into account the scale associated with the timer.
*
* This function is thread-safe but the timer and its timer list must not be
* freed while this function is running.
*/
void timer_mod_anticipate(QEMUTimer *ts, int64_t expire_time);
/**
* timer_pending:
* @ts: the timer
*
* Determines whether a timer is pending (i.e. is on the
* active list of timers, whether or not it has not yet expired).
*
* Returns: true if the timer is pending
*/
bool timer_pending(QEMUTimer *ts);
/**
* timer_expired:
* @ts: the timer
*
* Determines whether a timer has expired.
*
* Returns: true if the timer has expired
*/
bool timer_expired(QEMUTimer *timer_head, int64_t current_time);
/**
* timer_expire_time_ns:
* @ts: the timer
*
* Determine the expiry time of a timer
*
* Returns: the expiry time in nanoseconds
*/
uint64_t timer_expire_time_ns(QEMUTimer *ts);
/**
* timer_get:
* @f: the file
* @ts: the timer
*
* Read a timer @ts from a file @f
*/
void timer_get(QEMUFile *f, QEMUTimer *ts);
/**
* timer_put:
* @f: the file
* @ts: the timer
*/
void timer_put(QEMUFile *f, QEMUTimer *ts);
/*
* General utility functions
*/
/**
* qemu_timeout_ns_to_ms:
* @ns: nanosecond timeout value
*
* Convert a nanosecond timeout value (or -1) to
* a millisecond value (or -1), always rounding up.
*
* Returns: millisecond timeout value
*/
int qemu_timeout_ns_to_ms(int64_t ns);
/**
* qemu_poll_ns:
* @fds: Array of file descriptors
* @nfds: number of file descriptors
* @timeout: timeout in nanoseconds
*
* Perform a poll like g_poll but with a timeout in nanoseconds.
* See g_poll documentation for further details.
*
* Returns: number of fds ready
*/
int qemu_poll_ns(GPollFD *fds, guint nfds, int64_t timeout);
/**
* qemu_soonest_timeout:
* @timeout1: first timeout in nanoseconds (or -1 for infinite)
* @timeout2: second timeout in nanoseconds (or -1 for infinite)
*
* Calculates the soonest of two timeout values. -1 means infinite, which
* is later than any other value.
*
* Returns: soonest timeout value in nanoseconds (or -1 for infinite)
*/
static inline int64_t qemu_soonest_timeout(int64_t timeout1, int64_t timeout2)
{
/* we can abuse the fact that -1 (which means infinite) is a maximal
* value when cast to unsigned. As this is disgusting, it's kept in
* one inline function.
*/
return ((uint64_t) timeout1 < (uint64_t) timeout2) ? timeout1 : timeout2;
}
/**
* initclocks:
*
* Initialise the clock & timer infrastructure
*/
void init_clocks(void);
int64_t cpu_get_ticks(void);
/* Caller must hold BQL */
void cpu_enable_ticks(void);
/* Caller must hold BQL */
void cpu_disable_ticks(void);
static inline int64_t get_ticks_per_sec(void)
{
return 1000000000LL;
}
/*
* Low level clock functions
*/
/* real time host monotonic timer */
static inline int64_t get_clock_realtime(void)
{
struct timeval tv;
gettimeofday(&tv, NULL);
return tv.tv_sec * 1000000000LL + (tv.tv_usec * 1000);
}
/* Warning: don't insert tracepoints into these functions, they are
also used by simpletrace backend and tracepoints would cause
an infinite recursion! */
#ifdef _WIN32
extern int64_t clock_freq;
static inline int64_t get_clock(void)
{
LARGE_INTEGER ti;
QueryPerformanceCounter(&ti);
return muldiv64(ti.QuadPart, get_ticks_per_sec(), clock_freq);
}
#else
extern int use_rt_clock;
static inline int64_t get_clock(void)
{
#ifdef CLOCK_MONOTONIC
if (use_rt_clock) {
struct timespec ts;
clock_gettime(CLOCK_MONOTONIC, &ts);
return ts.tv_sec * 1000000000LL + ts.tv_nsec;
} else
#endif
{
/* XXX: using gettimeofday leads to problems if the date
changes, so it should be avoided. */
return get_clock_realtime();
}
}
#endif
/* icount */
int64_t cpu_get_icount_raw(void);
int64_t cpu_get_icount(void);
int64_t cpu_get_clock(void);
cpu-exec: Add sleeping algorithm The goal is to sleep qemu whenever the guest clock is in advance compared to the host clock (we use the monotonic clocks). The amount of time to sleep is calculated in the execution loop in cpu_exec. At first, we tried to approximate at each for loop the real time elapsed while searching for a TB (generating or retrieving from cache) and executing it. We would then approximate the virtual time corresponding to the number of virtual instructions executed. The difference between these 2 values would allow us to know if the guest is in advance or delayed. However, the function used for measuring the real time (qemu_clock_get_ns(QEMU_CLOCK_REALTIME)) proved to be very expensive. We had an added overhead of 13% of the total run time. Therefore, we modified the algorithm and only take into account the difference between the 2 clocks at the begining of the cpu_exec function. During the for loop we try to reduce the advance of the guest only by computing the virtual time elapsed and sleeping if necessary. The overhead is thus reduced to 3%. Even though this method still has a noticeable overhead, it no longer is a bottleneck in trying to achieve a better guest frequency for which the guest clock is faster than the host one. As for the the alignement of the 2 clocks, with the first algorithm the guest clock was oscillating between -1 and 1ms compared to the host clock. Using the second algorithm we notice that the guest is 5ms behind the host, which is still acceptable for our use case. The tests where conducted using fio and stress. The host machine in an i5 CPU at 3.10GHz running Debian Jessie (kernel 3.12). The guest machine is an arm versatile-pb built with buildroot. Currently, on our test machine, the lowest icount we can achieve that is suitable for aligning the 2 clocks is 6. However, we observe that the IO tests (using fio) are slower than the cpu tests (using stress). Signed-off-by: Sebastian Tanase <sebastian.tanase@openwide.fr> Tested-by: Camille Bégué <camille.begue@openwide.fr> Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2014-07-25 11:56:31 +02:00
int64_t cpu_get_clock_offset(void);
int64_t cpu_icount_to_ns(int64_t icount);
/*******************************************/
/* host CPU ticks (if available) */
#if defined(_ARCH_PPC)
static inline int64_t cpu_get_real_ticks(void)
{
int64_t retval;
#ifdef _ARCH_PPC64
/* This reads timebase in one 64bit go and includes Cell workaround from:
http://ozlabs.org/pipermail/linuxppc-dev/2006-October/027052.html
*/
__asm__ __volatile__ ("mftb %0\n\t"
"cmpwi %0,0\n\t"
"beq- $-8"
: "=r" (retval));
#else
/* http://ozlabs.org/pipermail/linuxppc-dev/1999-October/003889.html */
unsigned long junk;
__asm__ __volatile__ ("mfspr %1,269\n\t" /* mftbu */
"mfspr %L0,268\n\t" /* mftb */
"mfspr %0,269\n\t" /* mftbu */
"cmpw %0,%1\n\t"
"bne $-16"
: "=r" (retval), "=r" (junk));
#endif
return retval;
}
#elif defined(__i386__)
static inline int64_t cpu_get_real_ticks(void)
{
int64_t val;
asm volatile ("rdtsc" : "=A" (val));
return val;
}
#elif defined(__x86_64__)
static inline int64_t cpu_get_real_ticks(void)
{
uint32_t low,high;
int64_t val;
asm volatile("rdtsc" : "=a" (low), "=d" (high));
val = high;
val <<= 32;
val |= low;
return val;
}
#elif defined(__hppa__)
static inline int64_t cpu_get_real_ticks(void)
{
int val;
asm volatile ("mfctl %%cr16, %0" : "=r"(val));
return val;
}
#elif defined(__ia64)
static inline int64_t cpu_get_real_ticks(void)
{
int64_t val;
asm volatile ("mov %0 = ar.itc" : "=r"(val) :: "memory");
return val;
}
#elif defined(__s390__)
static inline int64_t cpu_get_real_ticks(void)
{
int64_t val;
asm volatile("stck 0(%1)" : "=m" (val) : "a" (&val) : "cc");
return val;
}
#elif defined(__sparc__)
static inline int64_t cpu_get_real_ticks (void)
{
#if defined(_LP64)
uint64_t rval;
asm volatile("rd %%tick,%0" : "=r"(rval));
return rval;
#else
/* We need an %o or %g register for this. For recent enough gcc
there is an "h" constraint for that. Don't bother with that. */
union {
uint64_t i64;
struct {
uint32_t high;
uint32_t low;
} i32;
} rval;
asm volatile("rd %%tick,%%g1; srlx %%g1,32,%0; mov %%g1,%1"
: "=r"(rval.i32.high), "=r"(rval.i32.low) : : "g1");
return rval.i64;
#endif
}
#elif defined(__mips__) && \
((defined(__mips_isa_rev) && __mips_isa_rev >= 2) || defined(__linux__))
/*
* binutils wants to use rdhwr only on mips32r2
* but as linux kernel emulate it, it's fine
* to use it.
*
*/
#define MIPS_RDHWR(rd, value) { \
__asm__ __volatile__ (".set push\n\t" \
".set mips32r2\n\t" \
"rdhwr %0, "rd"\n\t" \
".set pop" \
: "=r" (value)); \
}
static inline int64_t cpu_get_real_ticks(void)
{
/* On kernels >= 2.6.25 rdhwr <reg>, $2 and $3 are emulated */
uint32_t count;
static uint32_t cyc_per_count = 0;
if (!cyc_per_count) {
MIPS_RDHWR("$3", cyc_per_count);
}
MIPS_RDHWR("$2", count);
return (int64_t)(count * cyc_per_count);
}
#elif defined(__alpha__)
static inline int64_t cpu_get_real_ticks(void)
{
uint64_t cc;
uint32_t cur, ofs;
asm volatile("rpcc %0" : "=r"(cc));
cur = cc;
ofs = cc >> 32;
return cur - ofs;
}
#else
/* The host CPU doesn't have an easily accessible cycle counter.
Just return a monotonically increasing value. This will be
totally wrong, but hopefully better than nothing. */
static inline int64_t cpu_get_real_ticks (void)
{
static int64_t ticks = 0;
return ticks++;
}
#endif
#ifdef CONFIG_PROFILER
static inline int64_t profile_getclock(void)
{
return cpu_get_real_ticks();
}
extern int64_t qemu_time, qemu_time_start;
extern int64_t tlb_flush_time;
extern int64_t dev_time;
#endif
#endif