mirror of
https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git
synced 2024-08-23 17:30:02 +00:00
![Nicholas Piggin](/assets/img/avatar_default.png)
This reverts commitebb37cf3ff
. That commit does not play well with soft-masked irq state manipulations in idle, interrupt replay, and possibly others due to tracing code sometimes using irq_work_queue (e.g., in trace_hardirqs_on()). That can cause PACA_IRQ_DEC to become set when it is not expected, and be ignored or cleared or cause warnings. The net result seems to be missing an irq_work until the next timer interrupt in the worst case which is usually not going to be noticed, however it could be a long time if the tick is disabled, which is against the spirit of irq_work and might cause real problems. The idea is still solid, but it would need more work. It's not really clear if it would be worth added complexity, so revert this for now (not a straight revert, but replace with a comment explaining why we might see interrupts happening, and gives git blame something to find). Fixes:ebb37cf3ff
("powerpc/64: irq_work avoid interrupt when called with hardware irqs enabled") Signed-off-by: Nicholas Piggin <npiggin@gmail.com> Signed-off-by: Michael Ellerman <mpe@ellerman.id.au> Link: https://lore.kernel.org/r/20200402120401.1115883-1-npiggin@gmail.com
1217 lines
31 KiB
C
1217 lines
31 KiB
C
// SPDX-License-Identifier: GPL-2.0-or-later
|
|
/*
|
|
* Common time routines among all ppc machines.
|
|
*
|
|
* Written by Cort Dougan (cort@cs.nmt.edu) to merge
|
|
* Paul Mackerras' version and mine for PReP and Pmac.
|
|
* MPC8xx/MBX changes by Dan Malek (dmalek@jlc.net).
|
|
* Converted for 64-bit by Mike Corrigan (mikejc@us.ibm.com)
|
|
*
|
|
* First round of bugfixes by Gabriel Paubert (paubert@iram.es)
|
|
* to make clock more stable (2.4.0-test5). The only thing
|
|
* that this code assumes is that the timebases have been synchronized
|
|
* by firmware on SMP and are never stopped (never do sleep
|
|
* on SMP then, nap and doze are OK).
|
|
*
|
|
* Speeded up do_gettimeofday by getting rid of references to
|
|
* xtime (which required locks for consistency). (mikejc@us.ibm.com)
|
|
*
|
|
* TODO (not necessarily in this file):
|
|
* - improve precision and reproducibility of timebase frequency
|
|
* measurement at boot time.
|
|
* - for astronomical applications: add a new function to get
|
|
* non ambiguous timestamps even around leap seconds. This needs
|
|
* a new timestamp format and a good name.
|
|
*
|
|
* 1997-09-10 Updated NTP code according to technical memorandum Jan '96
|
|
* "A Kernel Model for Precision Timekeeping" by Dave Mills
|
|
*/
|
|
|
|
#include <linux/errno.h>
|
|
#include <linux/export.h>
|
|
#include <linux/sched.h>
|
|
#include <linux/sched/clock.h>
|
|
#include <linux/kernel.h>
|
|
#include <linux/param.h>
|
|
#include <linux/string.h>
|
|
#include <linux/mm.h>
|
|
#include <linux/interrupt.h>
|
|
#include <linux/timex.h>
|
|
#include <linux/kernel_stat.h>
|
|
#include <linux/time.h>
|
|
#include <linux/init.h>
|
|
#include <linux/profile.h>
|
|
#include <linux/cpu.h>
|
|
#include <linux/security.h>
|
|
#include <linux/percpu.h>
|
|
#include <linux/rtc.h>
|
|
#include <linux/jiffies.h>
|
|
#include <linux/posix-timers.h>
|
|
#include <linux/irq.h>
|
|
#include <linux/delay.h>
|
|
#include <linux/irq_work.h>
|
|
#include <linux/of_clk.h>
|
|
#include <linux/suspend.h>
|
|
#include <linux/sched/cputime.h>
|
|
#include <linux/processor.h>
|
|
#include <asm/trace.h>
|
|
|
|
#include <asm/io.h>
|
|
#include <asm/nvram.h>
|
|
#include <asm/cache.h>
|
|
#include <asm/machdep.h>
|
|
#include <linux/uaccess.h>
|
|
#include <asm/time.h>
|
|
#include <asm/prom.h>
|
|
#include <asm/irq.h>
|
|
#include <asm/div64.h>
|
|
#include <asm/smp.h>
|
|
#include <asm/vdso_datapage.h>
|
|
#include <asm/firmware.h>
|
|
#include <asm/asm-prototypes.h>
|
|
|
|
/* powerpc clocksource/clockevent code */
|
|
|
|
#include <linux/clockchips.h>
|
|
#include <linux/timekeeper_internal.h>
|
|
|
|
static u64 rtc_read(struct clocksource *);
|
|
static struct clocksource clocksource_rtc = {
|
|
.name = "rtc",
|
|
.rating = 400,
|
|
.flags = CLOCK_SOURCE_IS_CONTINUOUS,
|
|
.mask = CLOCKSOURCE_MASK(64),
|
|
.read = rtc_read,
|
|
};
|
|
|
|
static u64 timebase_read(struct clocksource *);
|
|
static struct clocksource clocksource_timebase = {
|
|
.name = "timebase",
|
|
.rating = 400,
|
|
.flags = CLOCK_SOURCE_IS_CONTINUOUS,
|
|
.mask = CLOCKSOURCE_MASK(64),
|
|
.read = timebase_read,
|
|
};
|
|
|
|
#define DECREMENTER_DEFAULT_MAX 0x7FFFFFFF
|
|
u64 decrementer_max = DECREMENTER_DEFAULT_MAX;
|
|
|
|
static int decrementer_set_next_event(unsigned long evt,
|
|
struct clock_event_device *dev);
|
|
static int decrementer_shutdown(struct clock_event_device *evt);
|
|
|
|
struct clock_event_device decrementer_clockevent = {
|
|
.name = "decrementer",
|
|
.rating = 200,
|
|
.irq = 0,
|
|
.set_next_event = decrementer_set_next_event,
|
|
.set_state_oneshot_stopped = decrementer_shutdown,
|
|
.set_state_shutdown = decrementer_shutdown,
|
|
.tick_resume = decrementer_shutdown,
|
|
.features = CLOCK_EVT_FEAT_ONESHOT |
|
|
CLOCK_EVT_FEAT_C3STOP,
|
|
};
|
|
EXPORT_SYMBOL(decrementer_clockevent);
|
|
|
|
DEFINE_PER_CPU(u64, decrementers_next_tb);
|
|
static DEFINE_PER_CPU(struct clock_event_device, decrementers);
|
|
|
|
#define XSEC_PER_SEC (1024*1024)
|
|
|
|
#ifdef CONFIG_PPC64
|
|
#define SCALE_XSEC(xsec, max) (((xsec) * max) / XSEC_PER_SEC)
|
|
#else
|
|
/* compute ((xsec << 12) * max) >> 32 */
|
|
#define SCALE_XSEC(xsec, max) mulhwu((xsec) << 12, max)
|
|
#endif
|
|
|
|
unsigned long tb_ticks_per_jiffy;
|
|
unsigned long tb_ticks_per_usec = 100; /* sane default */
|
|
EXPORT_SYMBOL(tb_ticks_per_usec);
|
|
unsigned long tb_ticks_per_sec;
|
|
EXPORT_SYMBOL(tb_ticks_per_sec); /* for cputime_t conversions */
|
|
|
|
DEFINE_SPINLOCK(rtc_lock);
|
|
EXPORT_SYMBOL_GPL(rtc_lock);
|
|
|
|
static u64 tb_to_ns_scale __read_mostly;
|
|
static unsigned tb_to_ns_shift __read_mostly;
|
|
static u64 boot_tb __read_mostly;
|
|
|
|
extern struct timezone sys_tz;
|
|
static long timezone_offset;
|
|
|
|
unsigned long ppc_proc_freq;
|
|
EXPORT_SYMBOL_GPL(ppc_proc_freq);
|
|
unsigned long ppc_tb_freq;
|
|
EXPORT_SYMBOL_GPL(ppc_tb_freq);
|
|
|
|
bool tb_invalid;
|
|
|
|
#ifdef CONFIG_VIRT_CPU_ACCOUNTING_NATIVE
|
|
/*
|
|
* Factor for converting from cputime_t (timebase ticks) to
|
|
* microseconds. This is stored as 0.64 fixed-point binary fraction.
|
|
*/
|
|
u64 __cputime_usec_factor;
|
|
EXPORT_SYMBOL(__cputime_usec_factor);
|
|
|
|
#ifdef CONFIG_PPC_SPLPAR
|
|
void (*dtl_consumer)(struct dtl_entry *, u64);
|
|
#endif
|
|
|
|
static void calc_cputime_factors(void)
|
|
{
|
|
struct div_result res;
|
|
|
|
div128_by_32(1000000, 0, tb_ticks_per_sec, &res);
|
|
__cputime_usec_factor = res.result_low;
|
|
}
|
|
|
|
/*
|
|
* Read the SPURR on systems that have it, otherwise the PURR,
|
|
* or if that doesn't exist return the timebase value passed in.
|
|
*/
|
|
static inline unsigned long read_spurr(unsigned long tb)
|
|
{
|
|
if (cpu_has_feature(CPU_FTR_SPURR))
|
|
return mfspr(SPRN_SPURR);
|
|
if (cpu_has_feature(CPU_FTR_PURR))
|
|
return mfspr(SPRN_PURR);
|
|
return tb;
|
|
}
|
|
|
|
#ifdef CONFIG_PPC_SPLPAR
|
|
|
|
/*
|
|
* Scan the dispatch trace log and count up the stolen time.
|
|
* Should be called with interrupts disabled.
|
|
*/
|
|
static u64 scan_dispatch_log(u64 stop_tb)
|
|
{
|
|
u64 i = local_paca->dtl_ridx;
|
|
struct dtl_entry *dtl = local_paca->dtl_curr;
|
|
struct dtl_entry *dtl_end = local_paca->dispatch_log_end;
|
|
struct lppaca *vpa = local_paca->lppaca_ptr;
|
|
u64 tb_delta;
|
|
u64 stolen = 0;
|
|
u64 dtb;
|
|
|
|
if (!dtl)
|
|
return 0;
|
|
|
|
if (i == be64_to_cpu(vpa->dtl_idx))
|
|
return 0;
|
|
while (i < be64_to_cpu(vpa->dtl_idx)) {
|
|
dtb = be64_to_cpu(dtl->timebase);
|
|
tb_delta = be32_to_cpu(dtl->enqueue_to_dispatch_time) +
|
|
be32_to_cpu(dtl->ready_to_enqueue_time);
|
|
barrier();
|
|
if (i + N_DISPATCH_LOG < be64_to_cpu(vpa->dtl_idx)) {
|
|
/* buffer has overflowed */
|
|
i = be64_to_cpu(vpa->dtl_idx) - N_DISPATCH_LOG;
|
|
dtl = local_paca->dispatch_log + (i % N_DISPATCH_LOG);
|
|
continue;
|
|
}
|
|
if (dtb > stop_tb)
|
|
break;
|
|
if (dtl_consumer)
|
|
dtl_consumer(dtl, i);
|
|
stolen += tb_delta;
|
|
++i;
|
|
++dtl;
|
|
if (dtl == dtl_end)
|
|
dtl = local_paca->dispatch_log;
|
|
}
|
|
local_paca->dtl_ridx = i;
|
|
local_paca->dtl_curr = dtl;
|
|
return stolen;
|
|
}
|
|
|
|
/*
|
|
* Accumulate stolen time by scanning the dispatch trace log.
|
|
* Called on entry from user mode.
|
|
*/
|
|
void notrace accumulate_stolen_time(void)
|
|
{
|
|
u64 sst, ust;
|
|
unsigned long save_irq_soft_mask = irq_soft_mask_return();
|
|
struct cpu_accounting_data *acct = &local_paca->accounting;
|
|
|
|
/* We are called early in the exception entry, before
|
|
* soft/hard_enabled are sync'ed to the expected state
|
|
* for the exception. We are hard disabled but the PACA
|
|
* needs to reflect that so various debug stuff doesn't
|
|
* complain
|
|
*/
|
|
irq_soft_mask_set(IRQS_DISABLED);
|
|
|
|
sst = scan_dispatch_log(acct->starttime_user);
|
|
ust = scan_dispatch_log(acct->starttime);
|
|
acct->stime -= sst;
|
|
acct->utime -= ust;
|
|
acct->steal_time += ust + sst;
|
|
|
|
irq_soft_mask_set(save_irq_soft_mask);
|
|
}
|
|
|
|
static inline u64 calculate_stolen_time(u64 stop_tb)
|
|
{
|
|
if (!firmware_has_feature(FW_FEATURE_SPLPAR))
|
|
return 0;
|
|
|
|
if (get_paca()->dtl_ridx != be64_to_cpu(get_lppaca()->dtl_idx))
|
|
return scan_dispatch_log(stop_tb);
|
|
|
|
return 0;
|
|
}
|
|
|
|
#else /* CONFIG_PPC_SPLPAR */
|
|
static inline u64 calculate_stolen_time(u64 stop_tb)
|
|
{
|
|
return 0;
|
|
}
|
|
|
|
#endif /* CONFIG_PPC_SPLPAR */
|
|
|
|
/*
|
|
* Account time for a transition between system, hard irq
|
|
* or soft irq state.
|
|
*/
|
|
static unsigned long vtime_delta_scaled(struct cpu_accounting_data *acct,
|
|
unsigned long now, unsigned long stime)
|
|
{
|
|
unsigned long stime_scaled = 0;
|
|
#ifdef CONFIG_ARCH_HAS_SCALED_CPUTIME
|
|
unsigned long nowscaled, deltascaled;
|
|
unsigned long utime, utime_scaled;
|
|
|
|
nowscaled = read_spurr(now);
|
|
deltascaled = nowscaled - acct->startspurr;
|
|
acct->startspurr = nowscaled;
|
|
utime = acct->utime - acct->utime_sspurr;
|
|
acct->utime_sspurr = acct->utime;
|
|
|
|
/*
|
|
* Because we don't read the SPURR on every kernel entry/exit,
|
|
* deltascaled includes both user and system SPURR ticks.
|
|
* Apportion these ticks to system SPURR ticks and user
|
|
* SPURR ticks in the same ratio as the system time (delta)
|
|
* and user time (udelta) values obtained from the timebase
|
|
* over the same interval. The system ticks get accounted here;
|
|
* the user ticks get saved up in paca->user_time_scaled to be
|
|
* used by account_process_tick.
|
|
*/
|
|
stime_scaled = stime;
|
|
utime_scaled = utime;
|
|
if (deltascaled != stime + utime) {
|
|
if (utime) {
|
|
stime_scaled = deltascaled * stime / (stime + utime);
|
|
utime_scaled = deltascaled - stime_scaled;
|
|
} else {
|
|
stime_scaled = deltascaled;
|
|
}
|
|
}
|
|
acct->utime_scaled += utime_scaled;
|
|
#endif
|
|
|
|
return stime_scaled;
|
|
}
|
|
|
|
static unsigned long vtime_delta(struct task_struct *tsk,
|
|
unsigned long *stime_scaled,
|
|
unsigned long *steal_time)
|
|
{
|
|
unsigned long now, stime;
|
|
struct cpu_accounting_data *acct = get_accounting(tsk);
|
|
|
|
WARN_ON_ONCE(!irqs_disabled());
|
|
|
|
now = mftb();
|
|
stime = now - acct->starttime;
|
|
acct->starttime = now;
|
|
|
|
*stime_scaled = vtime_delta_scaled(acct, now, stime);
|
|
|
|
*steal_time = calculate_stolen_time(now);
|
|
|
|
return stime;
|
|
}
|
|
|
|
void vtime_account_kernel(struct task_struct *tsk)
|
|
{
|
|
unsigned long stime, stime_scaled, steal_time;
|
|
struct cpu_accounting_data *acct = get_accounting(tsk);
|
|
|
|
stime = vtime_delta(tsk, &stime_scaled, &steal_time);
|
|
|
|
stime -= min(stime, steal_time);
|
|
acct->steal_time += steal_time;
|
|
|
|
if ((tsk->flags & PF_VCPU) && !irq_count()) {
|
|
acct->gtime += stime;
|
|
#ifdef CONFIG_ARCH_HAS_SCALED_CPUTIME
|
|
acct->utime_scaled += stime_scaled;
|
|
#endif
|
|
} else {
|
|
if (hardirq_count())
|
|
acct->hardirq_time += stime;
|
|
else if (in_serving_softirq())
|
|
acct->softirq_time += stime;
|
|
else
|
|
acct->stime += stime;
|
|
|
|
#ifdef CONFIG_ARCH_HAS_SCALED_CPUTIME
|
|
acct->stime_scaled += stime_scaled;
|
|
#endif
|
|
}
|
|
}
|
|
EXPORT_SYMBOL_GPL(vtime_account_kernel);
|
|
|
|
void vtime_account_idle(struct task_struct *tsk)
|
|
{
|
|
unsigned long stime, stime_scaled, steal_time;
|
|
struct cpu_accounting_data *acct = get_accounting(tsk);
|
|
|
|
stime = vtime_delta(tsk, &stime_scaled, &steal_time);
|
|
acct->idle_time += stime + steal_time;
|
|
}
|
|
|
|
static void vtime_flush_scaled(struct task_struct *tsk,
|
|
struct cpu_accounting_data *acct)
|
|
{
|
|
#ifdef CONFIG_ARCH_HAS_SCALED_CPUTIME
|
|
if (acct->utime_scaled)
|
|
tsk->utimescaled += cputime_to_nsecs(acct->utime_scaled);
|
|
if (acct->stime_scaled)
|
|
tsk->stimescaled += cputime_to_nsecs(acct->stime_scaled);
|
|
|
|
acct->utime_scaled = 0;
|
|
acct->utime_sspurr = 0;
|
|
acct->stime_scaled = 0;
|
|
#endif
|
|
}
|
|
|
|
/*
|
|
* Account the whole cputime accumulated in the paca
|
|
* Must be called with interrupts disabled.
|
|
* Assumes that vtime_account_kernel/idle() has been called
|
|
* recently (i.e. since the last entry from usermode) so that
|
|
* get_paca()->user_time_scaled is up to date.
|
|
*/
|
|
void vtime_flush(struct task_struct *tsk)
|
|
{
|
|
struct cpu_accounting_data *acct = get_accounting(tsk);
|
|
|
|
if (acct->utime)
|
|
account_user_time(tsk, cputime_to_nsecs(acct->utime));
|
|
|
|
if (acct->gtime)
|
|
account_guest_time(tsk, cputime_to_nsecs(acct->gtime));
|
|
|
|
if (IS_ENABLED(CONFIG_PPC_SPLPAR) && acct->steal_time) {
|
|
account_steal_time(cputime_to_nsecs(acct->steal_time));
|
|
acct->steal_time = 0;
|
|
}
|
|
|
|
if (acct->idle_time)
|
|
account_idle_time(cputime_to_nsecs(acct->idle_time));
|
|
|
|
if (acct->stime)
|
|
account_system_index_time(tsk, cputime_to_nsecs(acct->stime),
|
|
CPUTIME_SYSTEM);
|
|
|
|
if (acct->hardirq_time)
|
|
account_system_index_time(tsk, cputime_to_nsecs(acct->hardirq_time),
|
|
CPUTIME_IRQ);
|
|
if (acct->softirq_time)
|
|
account_system_index_time(tsk, cputime_to_nsecs(acct->softirq_time),
|
|
CPUTIME_SOFTIRQ);
|
|
|
|
vtime_flush_scaled(tsk, acct);
|
|
|
|
acct->utime = 0;
|
|
acct->gtime = 0;
|
|
acct->idle_time = 0;
|
|
acct->stime = 0;
|
|
acct->hardirq_time = 0;
|
|
acct->softirq_time = 0;
|
|
}
|
|
|
|
#else /* ! CONFIG_VIRT_CPU_ACCOUNTING_NATIVE */
|
|
#define calc_cputime_factors()
|
|
#endif
|
|
|
|
void __delay(unsigned long loops)
|
|
{
|
|
unsigned long start;
|
|
int diff;
|
|
|
|
spin_begin();
|
|
if (__USE_RTC()) {
|
|
start = get_rtcl();
|
|
do {
|
|
/* the RTCL register wraps at 1000000000 */
|
|
diff = get_rtcl() - start;
|
|
if (diff < 0)
|
|
diff += 1000000000;
|
|
spin_cpu_relax();
|
|
} while (diff < loops);
|
|
} else if (tb_invalid) {
|
|
/*
|
|
* TB is in error state and isn't ticking anymore.
|
|
* HMI handler was unable to recover from TB error.
|
|
* Return immediately, so that kernel won't get stuck here.
|
|
*/
|
|
spin_cpu_relax();
|
|
} else {
|
|
start = get_tbl();
|
|
while (get_tbl() - start < loops)
|
|
spin_cpu_relax();
|
|
}
|
|
spin_end();
|
|
}
|
|
EXPORT_SYMBOL(__delay);
|
|
|
|
void udelay(unsigned long usecs)
|
|
{
|
|
__delay(tb_ticks_per_usec * usecs);
|
|
}
|
|
EXPORT_SYMBOL(udelay);
|
|
|
|
#ifdef CONFIG_SMP
|
|
unsigned long profile_pc(struct pt_regs *regs)
|
|
{
|
|
unsigned long pc = instruction_pointer(regs);
|
|
|
|
if (in_lock_functions(pc))
|
|
return regs->link;
|
|
|
|
return pc;
|
|
}
|
|
EXPORT_SYMBOL(profile_pc);
|
|
#endif
|
|
|
|
#ifdef CONFIG_IRQ_WORK
|
|
|
|
/*
|
|
* 64-bit uses a byte in the PACA, 32-bit uses a per-cpu variable...
|
|
*/
|
|
#ifdef CONFIG_PPC64
|
|
static inline unsigned long test_irq_work_pending(void)
|
|
{
|
|
unsigned long x;
|
|
|
|
asm volatile("lbz %0,%1(13)"
|
|
: "=r" (x)
|
|
: "i" (offsetof(struct paca_struct, irq_work_pending)));
|
|
return x;
|
|
}
|
|
|
|
static inline void set_irq_work_pending_flag(void)
|
|
{
|
|
asm volatile("stb %0,%1(13)" : :
|
|
"r" (1),
|
|
"i" (offsetof(struct paca_struct, irq_work_pending)));
|
|
}
|
|
|
|
static inline void clear_irq_work_pending(void)
|
|
{
|
|
asm volatile("stb %0,%1(13)" : :
|
|
"r" (0),
|
|
"i" (offsetof(struct paca_struct, irq_work_pending)));
|
|
}
|
|
|
|
#else /* 32-bit */
|
|
|
|
DEFINE_PER_CPU(u8, irq_work_pending);
|
|
|
|
#define set_irq_work_pending_flag() __this_cpu_write(irq_work_pending, 1)
|
|
#define test_irq_work_pending() __this_cpu_read(irq_work_pending)
|
|
#define clear_irq_work_pending() __this_cpu_write(irq_work_pending, 0)
|
|
|
|
#endif /* 32 vs 64 bit */
|
|
|
|
void arch_irq_work_raise(void)
|
|
{
|
|
/*
|
|
* 64-bit code that uses irq soft-mask can just cause an immediate
|
|
* interrupt here that gets soft masked, if this is called under
|
|
* local_irq_disable(). It might be possible to prevent that happening
|
|
* by noticing interrupts are disabled and setting decrementer pending
|
|
* to be replayed when irqs are enabled. The problem there is that
|
|
* tracing can call irq_work_raise, including in code that does low
|
|
* level manipulations of irq soft-mask state (e.g., trace_hardirqs_on)
|
|
* which could get tangled up if we're messing with the same state
|
|
* here.
|
|
*/
|
|
preempt_disable();
|
|
set_irq_work_pending_flag();
|
|
set_dec(1);
|
|
preempt_enable();
|
|
}
|
|
|
|
#else /* CONFIG_IRQ_WORK */
|
|
|
|
#define test_irq_work_pending() 0
|
|
#define clear_irq_work_pending()
|
|
|
|
#endif /* CONFIG_IRQ_WORK */
|
|
|
|
/*
|
|
* timer_interrupt - gets called when the decrementer overflows,
|
|
* with interrupts disabled.
|
|
*/
|
|
void timer_interrupt(struct pt_regs *regs)
|
|
{
|
|
struct clock_event_device *evt = this_cpu_ptr(&decrementers);
|
|
u64 *next_tb = this_cpu_ptr(&decrementers_next_tb);
|
|
struct pt_regs *old_regs;
|
|
u64 now;
|
|
|
|
/* Some implementations of hotplug will get timer interrupts while
|
|
* offline, just ignore these and we also need to set
|
|
* decrementers_next_tb as MAX to make sure __check_irq_replay
|
|
* don't replay timer interrupt when return, otherwise we'll trap
|
|
* here infinitely :(
|
|
*/
|
|
if (unlikely(!cpu_online(smp_processor_id()))) {
|
|
*next_tb = ~(u64)0;
|
|
set_dec(decrementer_max);
|
|
return;
|
|
}
|
|
|
|
/* Ensure a positive value is written to the decrementer, or else
|
|
* some CPUs will continue to take decrementer exceptions. When the
|
|
* PPC_WATCHDOG (decrementer based) is configured, keep this at most
|
|
* 31 bits, which is about 4 seconds on most systems, which gives
|
|
* the watchdog a chance of catching timer interrupt hard lockups.
|
|
*/
|
|
if (IS_ENABLED(CONFIG_PPC_WATCHDOG))
|
|
set_dec(0x7fffffff);
|
|
else
|
|
set_dec(decrementer_max);
|
|
|
|
/* Conditionally hard-enable interrupts now that the DEC has been
|
|
* bumped to its maximum value
|
|
*/
|
|
may_hard_irq_enable();
|
|
|
|
|
|
#if defined(CONFIG_PPC32) && defined(CONFIG_PPC_PMAC)
|
|
if (atomic_read(&ppc_n_lost_interrupts) != 0)
|
|
do_IRQ(regs);
|
|
#endif
|
|
|
|
old_regs = set_irq_regs(regs);
|
|
irq_enter();
|
|
trace_timer_interrupt_entry(regs);
|
|
|
|
if (test_irq_work_pending()) {
|
|
clear_irq_work_pending();
|
|
irq_work_run();
|
|
}
|
|
|
|
now = get_tb_or_rtc();
|
|
if (now >= *next_tb) {
|
|
*next_tb = ~(u64)0;
|
|
if (evt->event_handler)
|
|
evt->event_handler(evt);
|
|
__this_cpu_inc(irq_stat.timer_irqs_event);
|
|
} else {
|
|
now = *next_tb - now;
|
|
if (now <= decrementer_max)
|
|
set_dec(now);
|
|
/* We may have raced with new irq work */
|
|
if (test_irq_work_pending())
|
|
set_dec(1);
|
|
__this_cpu_inc(irq_stat.timer_irqs_others);
|
|
}
|
|
|
|
trace_timer_interrupt_exit(regs);
|
|
irq_exit();
|
|
set_irq_regs(old_regs);
|
|
}
|
|
EXPORT_SYMBOL(timer_interrupt);
|
|
|
|
#ifdef CONFIG_GENERIC_CLOCKEVENTS_BROADCAST
|
|
void timer_broadcast_interrupt(void)
|
|
{
|
|
u64 *next_tb = this_cpu_ptr(&decrementers_next_tb);
|
|
|
|
*next_tb = ~(u64)0;
|
|
tick_receive_broadcast();
|
|
__this_cpu_inc(irq_stat.broadcast_irqs_event);
|
|
}
|
|
#endif
|
|
|
|
#ifdef CONFIG_SUSPEND
|
|
static void generic_suspend_disable_irqs(void)
|
|
{
|
|
/* Disable the decrementer, so that it doesn't interfere
|
|
* with suspending.
|
|
*/
|
|
|
|
set_dec(decrementer_max);
|
|
local_irq_disable();
|
|
set_dec(decrementer_max);
|
|
}
|
|
|
|
static void generic_suspend_enable_irqs(void)
|
|
{
|
|
local_irq_enable();
|
|
}
|
|
|
|
/* Overrides the weak version in kernel/power/main.c */
|
|
void arch_suspend_disable_irqs(void)
|
|
{
|
|
if (ppc_md.suspend_disable_irqs)
|
|
ppc_md.suspend_disable_irqs();
|
|
generic_suspend_disable_irqs();
|
|
}
|
|
|
|
/* Overrides the weak version in kernel/power/main.c */
|
|
void arch_suspend_enable_irqs(void)
|
|
{
|
|
generic_suspend_enable_irqs();
|
|
if (ppc_md.suspend_enable_irqs)
|
|
ppc_md.suspend_enable_irqs();
|
|
}
|
|
#endif
|
|
|
|
unsigned long long tb_to_ns(unsigned long long ticks)
|
|
{
|
|
return mulhdu(ticks, tb_to_ns_scale) << tb_to_ns_shift;
|
|
}
|
|
EXPORT_SYMBOL_GPL(tb_to_ns);
|
|
|
|
/*
|
|
* Scheduler clock - returns current time in nanosec units.
|
|
*
|
|
* Note: mulhdu(a, b) (multiply high double unsigned) returns
|
|
* the high 64 bits of a * b, i.e. (a * b) >> 64, where a and b
|
|
* are 64-bit unsigned numbers.
|
|
*/
|
|
notrace unsigned long long sched_clock(void)
|
|
{
|
|
if (__USE_RTC())
|
|
return get_rtc();
|
|
return mulhdu(get_tb() - boot_tb, tb_to_ns_scale) << tb_to_ns_shift;
|
|
}
|
|
|
|
|
|
#ifdef CONFIG_PPC_PSERIES
|
|
|
|
/*
|
|
* Running clock - attempts to give a view of time passing for a virtualised
|
|
* kernels.
|
|
* Uses the VTB register if available otherwise a next best guess.
|
|
*/
|
|
unsigned long long running_clock(void)
|
|
{
|
|
/*
|
|
* Don't read the VTB as a host since KVM does not switch in host
|
|
* timebase into the VTB when it takes a guest off the CPU, reading the
|
|
* VTB would result in reading 'last switched out' guest VTB.
|
|
*
|
|
* Host kernels are often compiled with CONFIG_PPC_PSERIES checked, it
|
|
* would be unsafe to rely only on the #ifdef above.
|
|
*/
|
|
if (firmware_has_feature(FW_FEATURE_LPAR) &&
|
|
cpu_has_feature(CPU_FTR_ARCH_207S))
|
|
return mulhdu(get_vtb() - boot_tb, tb_to_ns_scale) << tb_to_ns_shift;
|
|
|
|
/*
|
|
* This is a next best approximation without a VTB.
|
|
* On a host which is running bare metal there should never be any stolen
|
|
* time and on a host which doesn't do any virtualisation TB *should* equal
|
|
* VTB so it makes no difference anyway.
|
|
*/
|
|
return local_clock() - kcpustat_this_cpu->cpustat[CPUTIME_STEAL];
|
|
}
|
|
#endif
|
|
|
|
static int __init get_freq(char *name, int cells, unsigned long *val)
|
|
{
|
|
struct device_node *cpu;
|
|
const __be32 *fp;
|
|
int found = 0;
|
|
|
|
/* The cpu node should have timebase and clock frequency properties */
|
|
cpu = of_find_node_by_type(NULL, "cpu");
|
|
|
|
if (cpu) {
|
|
fp = of_get_property(cpu, name, NULL);
|
|
if (fp) {
|
|
found = 1;
|
|
*val = of_read_ulong(fp, cells);
|
|
}
|
|
|
|
of_node_put(cpu);
|
|
}
|
|
|
|
return found;
|
|
}
|
|
|
|
static void start_cpu_decrementer(void)
|
|
{
|
|
#if defined(CONFIG_BOOKE) || defined(CONFIG_40x)
|
|
unsigned int tcr;
|
|
|
|
/* Clear any pending timer interrupts */
|
|
mtspr(SPRN_TSR, TSR_ENW | TSR_WIS | TSR_DIS | TSR_FIS);
|
|
|
|
tcr = mfspr(SPRN_TCR);
|
|
/*
|
|
* The watchdog may have already been enabled by u-boot. So leave
|
|
* TRC[WP] (Watchdog Period) alone.
|
|
*/
|
|
tcr &= TCR_WP_MASK; /* Clear all bits except for TCR[WP] */
|
|
tcr |= TCR_DIE; /* Enable decrementer */
|
|
mtspr(SPRN_TCR, tcr);
|
|
#endif
|
|
}
|
|
|
|
void __init generic_calibrate_decr(void)
|
|
{
|
|
ppc_tb_freq = DEFAULT_TB_FREQ; /* hardcoded default */
|
|
|
|
if (!get_freq("ibm,extended-timebase-frequency", 2, &ppc_tb_freq) &&
|
|
!get_freq("timebase-frequency", 1, &ppc_tb_freq)) {
|
|
|
|
printk(KERN_ERR "WARNING: Estimating decrementer frequency "
|
|
"(not found)\n");
|
|
}
|
|
|
|
ppc_proc_freq = DEFAULT_PROC_FREQ; /* hardcoded default */
|
|
|
|
if (!get_freq("ibm,extended-clock-frequency", 2, &ppc_proc_freq) &&
|
|
!get_freq("clock-frequency", 1, &ppc_proc_freq)) {
|
|
|
|
printk(KERN_ERR "WARNING: Estimating processor frequency "
|
|
"(not found)\n");
|
|
}
|
|
}
|
|
|
|
int update_persistent_clock64(struct timespec64 now)
|
|
{
|
|
struct rtc_time tm;
|
|
|
|
if (!ppc_md.set_rtc_time)
|
|
return -ENODEV;
|
|
|
|
rtc_time64_to_tm(now.tv_sec + 1 + timezone_offset, &tm);
|
|
|
|
return ppc_md.set_rtc_time(&tm);
|
|
}
|
|
|
|
static void __read_persistent_clock(struct timespec64 *ts)
|
|
{
|
|
struct rtc_time tm;
|
|
static int first = 1;
|
|
|
|
ts->tv_nsec = 0;
|
|
/* XXX this is a litle fragile but will work okay in the short term */
|
|
if (first) {
|
|
first = 0;
|
|
if (ppc_md.time_init)
|
|
timezone_offset = ppc_md.time_init();
|
|
|
|
/* get_boot_time() isn't guaranteed to be safe to call late */
|
|
if (ppc_md.get_boot_time) {
|
|
ts->tv_sec = ppc_md.get_boot_time() - timezone_offset;
|
|
return;
|
|
}
|
|
}
|
|
if (!ppc_md.get_rtc_time) {
|
|
ts->tv_sec = 0;
|
|
return;
|
|
}
|
|
ppc_md.get_rtc_time(&tm);
|
|
|
|
ts->tv_sec = rtc_tm_to_time64(&tm);
|
|
}
|
|
|
|
void read_persistent_clock64(struct timespec64 *ts)
|
|
{
|
|
__read_persistent_clock(ts);
|
|
|
|
/* Sanitize it in case real time clock is set below EPOCH */
|
|
if (ts->tv_sec < 0) {
|
|
ts->tv_sec = 0;
|
|
ts->tv_nsec = 0;
|
|
}
|
|
|
|
}
|
|
|
|
/* clocksource code */
|
|
static notrace u64 rtc_read(struct clocksource *cs)
|
|
{
|
|
return (u64)get_rtc();
|
|
}
|
|
|
|
static notrace u64 timebase_read(struct clocksource *cs)
|
|
{
|
|
return (u64)get_tb();
|
|
}
|
|
|
|
|
|
void update_vsyscall(struct timekeeper *tk)
|
|
{
|
|
struct timespec64 xt;
|
|
struct clocksource *clock = tk->tkr_mono.clock;
|
|
u32 mult = tk->tkr_mono.mult;
|
|
u32 shift = tk->tkr_mono.shift;
|
|
u64 cycle_last = tk->tkr_mono.cycle_last;
|
|
u64 new_tb_to_xs, new_stamp_xsec;
|
|
u64 frac_sec;
|
|
|
|
if (clock != &clocksource_timebase)
|
|
return;
|
|
|
|
xt.tv_sec = tk->xtime_sec;
|
|
xt.tv_nsec = (long)(tk->tkr_mono.xtime_nsec >> tk->tkr_mono.shift);
|
|
|
|
/* Make userspace gettimeofday spin until we're done. */
|
|
++vdso_data->tb_update_count;
|
|
smp_mb();
|
|
|
|
/*
|
|
* This computes ((2^20 / 1e9) * mult) >> shift as a
|
|
* 0.64 fixed-point fraction.
|
|
* The computation in the else clause below won't overflow
|
|
* (as long as the timebase frequency is >= 1.049 MHz)
|
|
* but loses precision because we lose the low bits of the constant
|
|
* in the shift. Note that 19342813113834067 ~= 2^(20+64) / 1e9.
|
|
* For a shift of 24 the error is about 0.5e-9, or about 0.5ns
|
|
* over a second. (Shift values are usually 22, 23 or 24.)
|
|
* For high frequency clocks such as the 512MHz timebase clock
|
|
* on POWER[6789], the mult value is small (e.g. 32768000)
|
|
* and so we can shift the constant by 16 initially
|
|
* (295147905179 ~= 2^(20+64-16) / 1e9) and then do the
|
|
* remaining shifts after the multiplication, which gives a
|
|
* more accurate result (e.g. with mult = 32768000, shift = 24,
|
|
* the error is only about 1.2e-12, or 0.7ns over 10 minutes).
|
|
*/
|
|
if (mult <= 62500000 && clock->shift >= 16)
|
|
new_tb_to_xs = ((u64) mult * 295147905179ULL) >> (clock->shift - 16);
|
|
else
|
|
new_tb_to_xs = (u64) mult * (19342813113834067ULL >> clock->shift);
|
|
|
|
/*
|
|
* Compute the fractional second in units of 2^-32 seconds.
|
|
* The fractional second is tk->tkr_mono.xtime_nsec >> tk->tkr_mono.shift
|
|
* in nanoseconds, so multiplying that by 2^32 / 1e9 gives
|
|
* it in units of 2^-32 seconds.
|
|
* We assume shift <= 32 because clocks_calc_mult_shift()
|
|
* generates shift values in the range 0 - 32.
|
|
*/
|
|
frac_sec = tk->tkr_mono.xtime_nsec << (32 - shift);
|
|
do_div(frac_sec, NSEC_PER_SEC);
|
|
|
|
/*
|
|
* Work out new stamp_xsec value for any legacy users of systemcfg.
|
|
* stamp_xsec is in units of 2^-20 seconds.
|
|
*/
|
|
new_stamp_xsec = frac_sec >> 12;
|
|
new_stamp_xsec += tk->xtime_sec * XSEC_PER_SEC;
|
|
|
|
/*
|
|
* tb_update_count is used to allow the userspace gettimeofday code
|
|
* to assure itself that it sees a consistent view of the tb_to_xs and
|
|
* stamp_xsec variables. It reads the tb_update_count, then reads
|
|
* tb_to_xs and stamp_xsec and then reads tb_update_count again. If
|
|
* the two values of tb_update_count match and are even then the
|
|
* tb_to_xs and stamp_xsec values are consistent. If not, then it
|
|
* loops back and reads them again until this criteria is met.
|
|
*/
|
|
vdso_data->tb_orig_stamp = cycle_last;
|
|
vdso_data->stamp_xsec = new_stamp_xsec;
|
|
vdso_data->tb_to_xs = new_tb_to_xs;
|
|
vdso_data->wtom_clock_sec = tk->wall_to_monotonic.tv_sec;
|
|
vdso_data->wtom_clock_nsec = tk->wall_to_monotonic.tv_nsec;
|
|
vdso_data->stamp_xtime_sec = xt.tv_sec;
|
|
vdso_data->stamp_xtime_nsec = xt.tv_nsec;
|
|
vdso_data->stamp_sec_fraction = frac_sec;
|
|
vdso_data->hrtimer_res = hrtimer_resolution;
|
|
smp_wmb();
|
|
++(vdso_data->tb_update_count);
|
|
}
|
|
|
|
void update_vsyscall_tz(void)
|
|
{
|
|
vdso_data->tz_minuteswest = sys_tz.tz_minuteswest;
|
|
vdso_data->tz_dsttime = sys_tz.tz_dsttime;
|
|
}
|
|
|
|
static void __init clocksource_init(void)
|
|
{
|
|
struct clocksource *clock;
|
|
|
|
if (__USE_RTC())
|
|
clock = &clocksource_rtc;
|
|
else
|
|
clock = &clocksource_timebase;
|
|
|
|
if (clocksource_register_hz(clock, tb_ticks_per_sec)) {
|
|
printk(KERN_ERR "clocksource: %s is already registered\n",
|
|
clock->name);
|
|
return;
|
|
}
|
|
|
|
printk(KERN_INFO "clocksource: %s mult[%x] shift[%d] registered\n",
|
|
clock->name, clock->mult, clock->shift);
|
|
}
|
|
|
|
static int decrementer_set_next_event(unsigned long evt,
|
|
struct clock_event_device *dev)
|
|
{
|
|
__this_cpu_write(decrementers_next_tb, get_tb_or_rtc() + evt);
|
|
set_dec(evt);
|
|
|
|
/* We may have raced with new irq work */
|
|
if (test_irq_work_pending())
|
|
set_dec(1);
|
|
|
|
return 0;
|
|
}
|
|
|
|
static int decrementer_shutdown(struct clock_event_device *dev)
|
|
{
|
|
decrementer_set_next_event(decrementer_max, dev);
|
|
return 0;
|
|
}
|
|
|
|
static void register_decrementer_clockevent(int cpu)
|
|
{
|
|
struct clock_event_device *dec = &per_cpu(decrementers, cpu);
|
|
|
|
*dec = decrementer_clockevent;
|
|
dec->cpumask = cpumask_of(cpu);
|
|
|
|
clockevents_config_and_register(dec, ppc_tb_freq, 2, decrementer_max);
|
|
|
|
printk_once(KERN_DEBUG "clockevent: %s mult[%x] shift[%d] cpu[%d]\n",
|
|
dec->name, dec->mult, dec->shift, cpu);
|
|
|
|
/* Set values for KVM, see kvm_emulate_dec() */
|
|
decrementer_clockevent.mult = dec->mult;
|
|
decrementer_clockevent.shift = dec->shift;
|
|
}
|
|
|
|
static void enable_large_decrementer(void)
|
|
{
|
|
if (!cpu_has_feature(CPU_FTR_ARCH_300))
|
|
return;
|
|
|
|
if (decrementer_max <= DECREMENTER_DEFAULT_MAX)
|
|
return;
|
|
|
|
/*
|
|
* If we're running as the hypervisor we need to enable the LD manually
|
|
* otherwise firmware should have done it for us.
|
|
*/
|
|
if (cpu_has_feature(CPU_FTR_HVMODE))
|
|
mtspr(SPRN_LPCR, mfspr(SPRN_LPCR) | LPCR_LD);
|
|
}
|
|
|
|
static void __init set_decrementer_max(void)
|
|
{
|
|
struct device_node *cpu;
|
|
u32 bits = 32;
|
|
|
|
/* Prior to ISAv3 the decrementer is always 32 bit */
|
|
if (!cpu_has_feature(CPU_FTR_ARCH_300))
|
|
return;
|
|
|
|
cpu = of_find_node_by_type(NULL, "cpu");
|
|
|
|
if (of_property_read_u32(cpu, "ibm,dec-bits", &bits) == 0) {
|
|
if (bits > 64 || bits < 32) {
|
|
pr_warn("time_init: firmware supplied invalid ibm,dec-bits");
|
|
bits = 32;
|
|
}
|
|
|
|
/* calculate the signed maximum given this many bits */
|
|
decrementer_max = (1ul << (bits - 1)) - 1;
|
|
}
|
|
|
|
of_node_put(cpu);
|
|
|
|
pr_info("time_init: %u bit decrementer (max: %llx)\n",
|
|
bits, decrementer_max);
|
|
}
|
|
|
|
static void __init init_decrementer_clockevent(void)
|
|
{
|
|
register_decrementer_clockevent(smp_processor_id());
|
|
}
|
|
|
|
void secondary_cpu_time_init(void)
|
|
{
|
|
/* Enable and test the large decrementer for this cpu */
|
|
enable_large_decrementer();
|
|
|
|
/* Start the decrementer on CPUs that have manual control
|
|
* such as BookE
|
|
*/
|
|
start_cpu_decrementer();
|
|
|
|
/* FIME: Should make unrelatred change to move snapshot_timebase
|
|
* call here ! */
|
|
register_decrementer_clockevent(smp_processor_id());
|
|
}
|
|
|
|
/* This function is only called on the boot processor */
|
|
void __init time_init(void)
|
|
{
|
|
struct div_result res;
|
|
u64 scale;
|
|
unsigned shift;
|
|
|
|
if (__USE_RTC()) {
|
|
/* 601 processor: dec counts down by 128 every 128ns */
|
|
ppc_tb_freq = 1000000000;
|
|
} else {
|
|
/* Normal PowerPC with timebase register */
|
|
ppc_md.calibrate_decr();
|
|
printk(KERN_DEBUG "time_init: decrementer frequency = %lu.%.6lu MHz\n",
|
|
ppc_tb_freq / 1000000, ppc_tb_freq % 1000000);
|
|
printk(KERN_DEBUG "time_init: processor frequency = %lu.%.6lu MHz\n",
|
|
ppc_proc_freq / 1000000, ppc_proc_freq % 1000000);
|
|
}
|
|
|
|
tb_ticks_per_jiffy = ppc_tb_freq / HZ;
|
|
tb_ticks_per_sec = ppc_tb_freq;
|
|
tb_ticks_per_usec = ppc_tb_freq / 1000000;
|
|
calc_cputime_factors();
|
|
|
|
/*
|
|
* Compute scale factor for sched_clock.
|
|
* The calibrate_decr() function has set tb_ticks_per_sec,
|
|
* which is the timebase frequency.
|
|
* We compute 1e9 * 2^64 / tb_ticks_per_sec and interpret
|
|
* the 128-bit result as a 64.64 fixed-point number.
|
|
* We then shift that number right until it is less than 1.0,
|
|
* giving us the scale factor and shift count to use in
|
|
* sched_clock().
|
|
*/
|
|
div128_by_32(1000000000, 0, tb_ticks_per_sec, &res);
|
|
scale = res.result_low;
|
|
for (shift = 0; res.result_high != 0; ++shift) {
|
|
scale = (scale >> 1) | (res.result_high << 63);
|
|
res.result_high >>= 1;
|
|
}
|
|
tb_to_ns_scale = scale;
|
|
tb_to_ns_shift = shift;
|
|
/* Save the current timebase to pretty up CONFIG_PRINTK_TIME */
|
|
boot_tb = get_tb_or_rtc();
|
|
|
|
/* If platform provided a timezone (pmac), we correct the time */
|
|
if (timezone_offset) {
|
|
sys_tz.tz_minuteswest = -timezone_offset / 60;
|
|
sys_tz.tz_dsttime = 0;
|
|
}
|
|
|
|
vdso_data->tb_update_count = 0;
|
|
vdso_data->tb_ticks_per_sec = tb_ticks_per_sec;
|
|
|
|
/* initialise and enable the large decrementer (if we have one) */
|
|
set_decrementer_max();
|
|
enable_large_decrementer();
|
|
|
|
/* Start the decrementer on CPUs that have manual control
|
|
* such as BookE
|
|
*/
|
|
start_cpu_decrementer();
|
|
|
|
/* Register the clocksource */
|
|
clocksource_init();
|
|
|
|
init_decrementer_clockevent();
|
|
tick_setup_hrtimer_broadcast();
|
|
|
|
of_clk_init(NULL);
|
|
}
|
|
|
|
/*
|
|
* Divide a 128-bit dividend by a 32-bit divisor, leaving a 128 bit
|
|
* result.
|
|
*/
|
|
void div128_by_32(u64 dividend_high, u64 dividend_low,
|
|
unsigned divisor, struct div_result *dr)
|
|
{
|
|
unsigned long a, b, c, d;
|
|
unsigned long w, x, y, z;
|
|
u64 ra, rb, rc;
|
|
|
|
a = dividend_high >> 32;
|
|
b = dividend_high & 0xffffffff;
|
|
c = dividend_low >> 32;
|
|
d = dividend_low & 0xffffffff;
|
|
|
|
w = a / divisor;
|
|
ra = ((u64)(a - (w * divisor)) << 32) + b;
|
|
|
|
rb = ((u64) do_div(ra, divisor) << 32) + c;
|
|
x = ra;
|
|
|
|
rc = ((u64) do_div(rb, divisor) << 32) + d;
|
|
y = rb;
|
|
|
|
do_div(rc, divisor);
|
|
z = rc;
|
|
|
|
dr->result_high = ((u64)w << 32) + x;
|
|
dr->result_low = ((u64)y << 32) + z;
|
|
|
|
}
|
|
|
|
/* We don't need to calibrate delay, we use the CPU timebase for that */
|
|
void calibrate_delay(void)
|
|
{
|
|
/* Some generic code (such as spinlock debug) use loops_per_jiffy
|
|
* as the number of __delay(1) in a jiffy, so make it so
|
|
*/
|
|
loops_per_jiffy = tb_ticks_per_jiffy;
|
|
}
|
|
|
|
#if IS_ENABLED(CONFIG_RTC_DRV_GENERIC)
|
|
static int rtc_generic_get_time(struct device *dev, struct rtc_time *tm)
|
|
{
|
|
ppc_md.get_rtc_time(tm);
|
|
return 0;
|
|
}
|
|
|
|
static int rtc_generic_set_time(struct device *dev, struct rtc_time *tm)
|
|
{
|
|
if (!ppc_md.set_rtc_time)
|
|
return -EOPNOTSUPP;
|
|
|
|
if (ppc_md.set_rtc_time(tm) < 0)
|
|
return -EOPNOTSUPP;
|
|
|
|
return 0;
|
|
}
|
|
|
|
static const struct rtc_class_ops rtc_generic_ops = {
|
|
.read_time = rtc_generic_get_time,
|
|
.set_time = rtc_generic_set_time,
|
|
};
|
|
|
|
static int __init rtc_init(void)
|
|
{
|
|
struct platform_device *pdev;
|
|
|
|
if (!ppc_md.get_rtc_time)
|
|
return -ENODEV;
|
|
|
|
pdev = platform_device_register_data(NULL, "rtc-generic", -1,
|
|
&rtc_generic_ops,
|
|
sizeof(rtc_generic_ops));
|
|
|
|
return PTR_ERR_OR_ZERO(pdev);
|
|
}
|
|
|
|
device_initcall(rtc_init);
|
|
#endif
|