[PATCH] uml: move libc-dependent time code

The serial UML OS-abstraction layer patch (um/kernel dir).

This moves all systemcalls from time.c file under os-Linux dir and joins
time.c and tine_kernel.c files

Signed-off-by: Gennady Sharapov <[e-mail]>
Signed-off-by: Jeff Dike <[e-mail]>
Cc: Paolo 'Blaisorblade' Giarrusso <[e-mail]>
Signed-off-by: Andrew Morton <[e-mail]>
Signed-off-by: Linus Torvalds <[e-mail]>

arch/um/include/os.h

···
 			     int r, int w, int x);
 extern int os_unmap_memory(void *addr, int len);
 extern void os_flush_stdout(void);
-extern unsigned long long os_usecs(void);
 
 /* tt.c
  * for tt mode only (will be deleted in future...)
···
 extern void setup_machinename(char *machine_out);
 extern void setup_hostinfo(void);
 extern int setjmp_wrapper(void (*proc)(void *, void *), ...);
+
+/* time.c */
+#define BILLION (1000 * 1000 * 1000)
+
+extern void switch_timers(int to_real);
+extern void idle_sleep(int secs);
+extern void enable_timer(void);
+extern void disable_timer(void);
+extern void user_time_init(void);
+extern void uml_idle_timer(void);
+extern unsigned long long os_nsecs(void);
 
 #endif

arch/um/include/time_user.h

···
-/* 
- * Copyright (C) 2002 Jeff Dike ([e-mail])
- * Licensed under the GPL
- */
-
-#ifndef __TIME_USER_H__
-#define __TIME_USER_H__
-
-extern void timer(void);
-extern void switch_timers(int to_real);
-extern void idle_sleep(int secs);
-extern void enable_timer(void);
-extern void prepare_timer(void * ptr);
-extern void disable_timer(void);
-extern unsigned long time_lock(void);
-extern void time_unlock(unsigned long);
-extern void user_time_init(void);
-
-#endif

arch/um/kernel/Makefile

···
 obj-y = config.o exec_kern.o exitcode.o \
 	init_task.o irq.o irq_user.o ksyms.o mem.o physmem.o \
 	process_kern.o ptrace.o reboot.o resource.o sigio_user.o sigio_kern.o \
-	signal_kern.o smp.o syscall_kern.o sysrq.o time.o \
+	signal_kern.o smp.o syscall_kern.o sysrq.o \
 	time_kern.o tlb.o trap_kern.o uaccess.o um_arch.o umid.o
 
 obj-$(CONFIG_BLK_DEV_INITRD) += initrd.o
···
 
 user-objs-$(CONFIG_TTY_LOG) += tty_log.o
 
-USER_OBJS := $(user-objs-y) config.o time.o tty_log.o
+USER_OBJS := $(user-objs-y) config.o tty_log.o
 
 include arch/um/scripts/Makefile.rules
 

arch/um/kernel/exec_kern.c

···
 #include "irq_user.h"
 #include "tlb.h"
 #include "os.h"
-#include "time_user.h"
 #include "choose-mode.h"
 #include "mode_kern.h"
 

arch/um/kernel/process_kern.c

···
 #include "init.h"
 #include "irq_user.h"
 #include "mem_user.h"
-#include "time_user.h"
 #include "tlb.h"
 #include "frame_kern.h"
 #include "sigcontext.h"

arch/um/kernel/skas/process.c

···
 #include <asm/types.h>
 #include "user.h"
 #include "ptrace_user.h"
-#include "time_user.h"
 #include "sysdep/ptrace.h"
 #include "user_util.h"
 #include "kern_util.h"

arch/um/kernel/skas/process_kern.c

···
 #include "asm/uaccess.h"
 #include "asm/atomic.h"
 #include "kern_util.h"
-#include "time_user.h"
 #include "skas.h"
 #include "os.h"
 #include "user_util.h"

arch/um/kernel/syscall.c

···
 	syscall_record[index].syscall = syscall;
 	syscall_record[index].pid = current_pid();
 	syscall_record[index].result = 0xdeadbeef;
-	syscall_record[index].start = os_usecs();
+	syscall_record[index].start = os_nsecs();
 	return(index);
 }
 
 void record_syscall_end(int index, long result)
 {
 	syscall_record[index].result = result;
-	syscall_record[index].end = os_usecs();
+	syscall_record[index].end = os_nsecs();
 }

arch/um/kernel/time_kern.c

···
-/* 
+/*
  * Copyright (C) 2000 Jeff Dike ([e-mail])
  * Licensed under the GPL
  */
···
 #include "linux/interrupt.h"
 #include "linux/init.h"
 #include "linux/delay.h"
+#include "linux/hrtimer.h"
 #include "asm/irq.h"
 #include "asm/param.h"
 #include "asm/current.h"
 #include "kern_util.h"
 #include "user_util.h"
-#include "time_user.h"
 #include "mode.h"
 #include "os.h"
 
···
 int timer_irq_inited = 0;
 
 static int first_tick;
-static unsigned long long prev_usecs;
+static unsigned long long prev_nsecs;
 #ifdef CONFIG_UML_REAL_TIME_CLOCK
 static long long delta;   		/* Deviation per interval */
 #endif
···
 	if(first_tick){
 #ifdef CONFIG_UML_REAL_TIME_CLOCK
 		/* We've had 1 tick */
-		unsigned long long usecs = os_usecs();
+		unsigned long long nsecs = os_nsecs();
 
-		delta += usecs - prev_usecs;
-		prev_usecs = usecs;
+		delta += nsecs - prev_nsecs;
+		prev_nsecs = nsecs;
 
 		/* Protect against the host clock being set backwards */
 		if(delta < 0)
 			delta = 0;
 
-		ticks += (delta * HZ) / MILLION;
-		delta -= (ticks * MILLION) / HZ;
+		ticks += (delta * HZ) / BILLION;
+		delta -= (ticks * BILLION) / HZ;
 #else
 		ticks = 1;
 #endif
 	}
 	else {
-		prev_usecs = os_usecs();
+		prev_nsecs = os_nsecs();
 		first_tick = 1;
 	}
 
···
 {
 	struct pt_regs regs;
 
-	CHOOSE_MODE((void) 
+	CHOOSE_MODE((void)
 		    (UPT_SC(&regs.regs) = (struct sigcontext *) (&sig + 1)),
 		    (void) (regs.regs.skas.is_user = 0));
 	do_timer(&regs);
 }
 
+static DEFINE_SPINLOCK(timer_spinlock);
+
+static unsigned long long local_offset = 0;
+
+static inline unsigned long long get_time(void)
+{
+	unsigned long long nsecs;
+	unsigned long flags;
+
+	spin_lock_irqsave(&timer_spinlock, flags);
+	nsecs = os_nsecs();
+	nsecs += local_offset;
+	spin_unlock_irqrestore(&timer_spinlock, flags);
+
+	return nsecs;
+}
+
 irqreturn_t um_timer(int irq, void *dev, struct pt_regs *regs)
 {
+	unsigned long long nsecs;
 	unsigned long flags;
 
 	do_timer(regs);
+
 	write_seqlock_irqsave(&xtime_lock, flags);
-	timer();
+	nsecs = get_time() + local_offset;
+	xtime.tv_sec = nsecs / NSEC_PER_SEC;
+	xtime.tv_nsec = nsecs - xtime.tv_sec * NSEC_PER_SEC;
 	write_sequnlock_irqrestore(&xtime_lock, flags);
+
 	return(IRQ_HANDLED);
 }
 
 long um_time(int __user *tloc)
 {
-	struct timeval now;
+	long ret = get_time() / NSEC_PER_SEC;
 
-	do_gettimeofday(&now);
-	if (tloc) {
- 		if (put_user(now.tv_sec, tloc))
-			now.tv_sec = -EFAULT;
-	}
-	return now.tv_sec;
+	if((tloc != NULL) && put_user(ret, tloc))
+		return -EFAULT;
+
+	return ret;
+}
+
+void do_gettimeofday(struct timeval *tv)
+{
+	unsigned long long nsecs = get_time();
+
+	tv->tv_sec = nsecs / NSEC_PER_SEC;
+	/* Careful about calculations here - this was originally done as
+	 * (nsecs - tv->tv_sec * NSEC_PER_SEC) / NSEC_PER_USEC
+	 * which gave bogus (> 1000000) values.  Dunno why, suspect gcc
+	 * (4.0.0) miscompiled it, or there's a subtle 64/32-bit conversion
+	 * problem that I missed.
+	 */
+	nsecs -= tv->tv_sec * NSEC_PER_SEC;
+	tv->tv_usec = (unsigned long) nsecs / NSEC_PER_USEC;
+}
+
+static inline void set_time(unsigned long long nsecs)
+{
+	unsigned long long now;
+	unsigned long flags;
+
+	spin_lock_irqsave(&timer_spinlock, flags);
+	now = os_nsecs();
+	local_offset = nsecs - now;
+	spin_unlock_irqrestore(&timer_spinlock, flags);
+
+	clock_was_set();
 }
 
 long um_stime(int __user *tptr)
 {
 	int value;
-	struct timespec new;
 
 	if (get_user(value, tptr))
                 return -EFAULT;
-	new.tv_sec = value;
-	new.tv_nsec = 0;
-	do_settimeofday(&new);
+
+	set_time((unsigned long long) value * NSEC_PER_SEC);
+
+	return 0;
+}
+
+int do_settimeofday(struct timespec *tv)
+{
+	set_time((unsigned long long) tv->tv_sec * NSEC_PER_SEC + tv->tv_nsec);
+
 	return 0;
 }
 
···
 	local_irq_enable();
 	if(current_thread->cpu == 0)
 		timer_irq(regs);
-}
-
-static DEFINE_SPINLOCK(timer_spinlock);
-
-unsigned long time_lock(void)
-{
-	unsigned long flags;
-
-	spin_lock_irqsave(&timer_spinlock, flags);
-	return(flags);
-}
-
-void time_unlock(unsigned long flags)
-{
-	spin_unlock_irqrestore(&timer_spinlock, flags);
 }
 
 int __init timer_init(void)
···
 }
 
 __initcall(timer_init);
-
-/*
- * Overrides for Emacs so that we follow Linus's tabbing style.
- * Emacs will notice this stuff at the end of the file and automatically
- * adjust the settings for this buffer only.  This must remain at the end
- * of the file.
- * ---------------------------------------------------------------------------
- * Local variables:
- * c-file-style: "linux"
- * End:
- */

arch/um/kernel/tt/exec_kern.c

···
 #include "user_util.h"
 #include "kern_util.h"
 #include "irq_user.h"
-#include "time_user.h"
 #include "mem_user.h"
 #include "os.h"
 #include "tlb.h"

arch/um/kernel/tt/process_kern.c

···
 #include "os.h"
 #include "kern.h"
 #include "sigcontext.h"
-#include "time_user.h"
 #include "mem_user.h"
 #include "tlb.h"
 #include "mode.h"

arch/um/os-Linux/main.c

···
 #include "user_util.h"
 #include "kern_util.h"
 #include "mem_user.h"
-#include "time_user.h"
 #include "irq_user.h"
 #include "user.h"
 #include "init.h"

arch/um/os-Linux/signal.c

···
 #include "sysdep/sigcontext.h"
 #include "sysdep/signal.h"
 #include "sigcontext.h"
-#include "time_user.h"
 #include "mode.h"
+#include "os.h"
 
 void sig_handler(ARCH_SIGHDLR_PARAM)
 {

arch/um/os-Linux/start_up.c

···
 #include "irq_user.h"
 #include "ptrace_user.h"
 #include "mem_user.h"
-#include "time_user.h"
 #include "init.h"
 #include "os.h"
 #include "uml-config.h"

arch/um/os-Linux/time.c

···
-#include <stdlib.h>
-#include <sys/time.h>
+/*
+ * Copyright (C) 2000, 2001, 2002 Jeff Dike ([e-mail])
+ * Licensed under the GPL
+ */
 
-unsigned long long os_usecs(void)
+#include <stdio.h>
+#include <stdlib.h>
+#include <unistd.h>
+#include <time.h>
+#include <sys/time.h>
+#include <signal.h>
+#include <errno.h>
+#include "user_util.h"
+#include "kern_util.h"
+#include "user.h"
+#include "process.h"
+#include "kern_constants.h"
+#include "os.h"
+
+/* XXX This really needs to be declared and initialized in a kernel file since
+ * it's in <linux/time.h>
+ */
+extern struct timespec wall_to_monotonic;
+
+static void set_interval(int timer_type)
+{
+	int usec = 1000000/hz();
+	struct itimerval interval = ((struct itimerval) { { 0, usec },
+							  { 0, usec } });
+
+	if(setitimer(timer_type, &interval, NULL) == -1)
+		panic("setitimer failed - errno = %d\n", errno);
+}
+
+void enable_timer(void)
+{
+	set_interval(ITIMER_VIRTUAL);
+}
+
+void disable_timer(void)
+{
+	struct itimerval disable = ((struct itimerval) { { 0, 0 }, { 0, 0 }});
+	if((setitimer(ITIMER_VIRTUAL, &disable, NULL) < 0) ||
+	   (setitimer(ITIMER_REAL, &disable, NULL) < 0))
+		printk("disnable_timer - setitimer failed, errno = %d\n",
+		       errno);
+	/* If there are signals already queued, after unblocking ignore them */
+	set_handler(SIGALRM, SIG_IGN, 0, -1);
+	set_handler(SIGVTALRM, SIG_IGN, 0, -1);
+}
+
+void switch_timers(int to_real)
+{
+	struct itimerval disable = ((struct itimerval) { { 0, 0 }, { 0, 0 }});
+	struct itimerval enable = ((struct itimerval) { { 0, 1000000/hz() },
+							{ 0, 1000000/hz() }});
+	int old, new;
+
+	if(to_real){
+		old = ITIMER_VIRTUAL;
+		new = ITIMER_REAL;
+	}
+	else {
+		old = ITIMER_REAL;
+		new = ITIMER_VIRTUAL;
+	}
+
+	if((setitimer(old, &disable, NULL) < 0) ||
+	   (setitimer(new, &enable, NULL)))
+		printk("switch_timers - setitimer failed, errno = %d\n",
+		       errno);
+}
+
+void uml_idle_timer(void)
+{
+	if(signal(SIGVTALRM, SIG_IGN) == SIG_ERR)
+		panic("Couldn't unset SIGVTALRM handler");
+
+	set_handler(SIGALRM, (__sighandler_t) alarm_handler,
+		    SA_RESTART, SIGUSR1, SIGIO, SIGWINCH, SIGVTALRM, -1);
+	set_interval(ITIMER_REAL);
+}
+
+extern void ktime_get_ts(struct timespec *ts);
+#define do_posix_clock_monotonic_gettime(ts) ktime_get_ts(ts)
+
+void time_init(void)
+{
+	struct timespec now;
+
+	if(signal(SIGVTALRM, boot_timer_handler) == SIG_ERR)
+		panic("Couldn't set SIGVTALRM handler");
+	set_interval(ITIMER_VIRTUAL);
+
+	do_posix_clock_monotonic_gettime(&now);
+	wall_to_monotonic.tv_sec = -now.tv_sec;
+	wall_to_monotonic.tv_nsec = -now.tv_nsec;
+}
+
+unsigned long long os_nsecs(void)
 {
 	struct timeval tv;
 
 	gettimeofday(&tv, NULL);
-	return((unsigned long long) tv.tv_sec * 1000000 + tv.tv_usec);
+	return((unsigned long long) tv.tv_sec * BILLION + tv.tv_usec * 1000);
 }
 
-/*
- * Overrides for Emacs so that we follow Linus's tabbing style.
- * Emacs will notice this stuff at the end of the file and automatically
- * adjust the settings for this buffer only.  This must remain at the end
- * of the file.
- * ---------------------------------------------------------------------------
- * Local variables:
- * c-file-style: "linux"
- * End:
- */
+void idle_sleep(int secs)
+{
+	struct timespec ts;
+
+	ts.tv_sec = secs;
+	ts.tv_nsec = 0;
+	nanosleep(&ts, NULL);
+}
+
+/* XXX This partly duplicates init_irq_signals */
+
+void user_time_init(void)
+{
+	set_handler(SIGVTALRM, (__sighandler_t) alarm_handler,
+		    SA_ONSTACK | SA_RESTART, SIGUSR1, SIGIO, SIGWINCH,
+		    SIGALRM, SIGUSR2, -1);
+	set_handler(SIGALRM, (__sighandler_t) alarm_handler,
+		    SA_ONSTACK | SA_RESTART, SIGUSR1, SIGIO, SIGWINCH,
+		    SIGVTALRM, SIGUSR2, -1);
+	set_interval(ITIMER_VIRTUAL);
+}

arch/um/os-Linux/tt.c

···
 #include "sysdep/sigcontext.h"
 #include "irq_user.h"
 #include "ptrace_user.h"
-#include "time_user.h"
 #include "init.h"
 #include "os.h"
 #include "uml-config.h"