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authorMartin Schwidefsky <schwidefsky@de.ibm.com>2005-05-01 11:58:57 -0400
committerLinus Torvalds <torvalds@ppc970.osdl.org>2005-05-01 11:58:57 -0400
commit4b7e0706620e3947dc1685dfdbc1413404afb545 (patch)
treec5ba1c919b6d1ca1141fbb0b6e9e0e933a51cc89 /arch/s390
parentb2c6678c858c5e54d95b996754adfb319cf65735 (diff)
[PATCH] s390: idle timer setup
Fix overflow in calculation of the new tod value in stop_hz_timer and fix wrong virtual timer list idle time in case the virtual timer is already expired in stop_cpu_timer. Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com> Signed-off-by: Andrew Morton <akpm@osdl.org> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
Diffstat (limited to 'arch/s390')
-rw-r--r--arch/s390/kernel/time.c12
-rw-r--r--arch/s390/kernel/vtime.c25
2 files changed, 22 insertions, 15 deletions
diff --git a/arch/s390/kernel/time.c b/arch/s390/kernel/time.c
index 061e81138dc..8ca48567678 100644
--- a/arch/s390/kernel/time.c
+++ b/arch/s390/kernel/time.c
@@ -244,7 +244,7 @@ int sysctl_hz_timer = 1;
244 */ 244 */
245static inline void stop_hz_timer(void) 245static inline void stop_hz_timer(void)
246{ 246{
247 __u64 timer; 247 __u64 timer, todval;
248 248
249 if (sysctl_hz_timer != 0) 249 if (sysctl_hz_timer != 0)
250 return; 250 return;
@@ -265,8 +265,14 @@ static inline void stop_hz_timer(void)
265 * for the next event. 265 * for the next event.
266 */ 266 */
267 timer = (__u64) (next_timer_interrupt() - jiffies) + jiffies_64; 267 timer = (__u64) (next_timer_interrupt() - jiffies) + jiffies_64;
268 timer = jiffies_timer_cc + timer * CLK_TICKS_PER_JIFFY; 268 todval = -1ULL;
269 asm volatile ("SCKC %0" : : "m" (timer)); 269 /* Be careful about overflows. */
270 if (timer < (-1ULL / CLK_TICKS_PER_JIFFY)) {
271 timer = jiffies_timer_cc + timer * CLK_TICKS_PER_JIFFY;
272 if (timer >= jiffies_timer_cc)
273 todval = timer;
274 }
275 asm volatile ("SCKC %0" : : "m" (todval));
270} 276}
271 277
272/* 278/*
diff --git a/arch/s390/kernel/vtime.c b/arch/s390/kernel/vtime.c
index bb6cf02418a..fa0726507b3 100644
--- a/arch/s390/kernel/vtime.c
+++ b/arch/s390/kernel/vtime.c
@@ -122,12 +122,17 @@ static void start_cpu_timer(void)
122 struct vtimer_queue *vt_list; 122 struct vtimer_queue *vt_list;
123 123
124 vt_list = &per_cpu(virt_cpu_timer, smp_processor_id()); 124 vt_list = &per_cpu(virt_cpu_timer, smp_processor_id());
125 set_vtimer(vt_list->idle); 125
126 /* CPU timer interrupt is pending, don't reprogramm it */
127 if (vt_list->idle & 1LL<<63)
128 return;
129
130 if (!list_empty(&vt_list->list))
131 set_vtimer(vt_list->idle);
126} 132}
127 133
128static void stop_cpu_timer(void) 134static void stop_cpu_timer(void)
129{ 135{
130 __u64 done;
131 struct vtimer_queue *vt_list; 136 struct vtimer_queue *vt_list;
132 137
133 vt_list = &per_cpu(virt_cpu_timer, smp_processor_id()); 138 vt_list = &per_cpu(virt_cpu_timer, smp_processor_id());
@@ -138,21 +143,17 @@ static void stop_cpu_timer(void)
138 goto fire; 143 goto fire;
139 } 144 }
140 145
141 /* store progress */ 146 /* store the actual expire value */
142 asm volatile ("STPT %0" : "=m" (done)); 147 asm volatile ("STPT %0" : "=m" (vt_list->idle));
143 148
144 /* 149 /*
145 * If done is negative we do not stop the CPU timer 150 * If the CPU timer is negative we don't reprogramm
146 * because we will get instantly an interrupt that 151 * it because we will get instantly an interrupt.
147 * will start the CPU timer again.
148 */ 152 */
149 if (done & 1LL<<63) 153 if (vt_list->idle & 1LL<<63)
150 return; 154 return;
151 else
152 vt_list->offset += vt_list->to_expire - done;
153 155
154 /* save the actual expire value */ 156 vt_list->offset += vt_list->to_expire - vt_list->idle;
155 vt_list->idle = done;
156 157
157 /* 158 /*
158 * We cannot halt the CPU timer, we just write a value that 159 * We cannot halt the CPU timer, we just write a value that