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authorLinus Torvalds <torvalds@linux-foundation.org>2011-05-19 20:44:13 -0400
committerLinus Torvalds <torvalds@linux-foundation.org>2011-05-19 20:44:13 -0400
commit0f1bdc1815c4cb29b3cd71a7091b478e426faa0b (patch)
treeb4d70c6a305d91bf7d1c8a6bbf87508587d55633 /arch/x86/kernel
parent80fe02b5daf176f99d3afc8f6c9dc9dece019836 (diff)
parenta18f22a968de17b29f2310cdb7ba69163e65ec15 (diff)
Merge branch 'timers-clocksource-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/linux-2.6-tip
* 'timers-clocksource-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/linux-2.6-tip: clocksource: convert mips to generic i8253 clocksource clocksource: convert x86 to generic i8253 clocksource clocksource: convert footbridge to generic i8253 clocksource clocksource: add common i8253 PIT clocksource blackfin: convert to clocksource_register_hz mips: convert to clocksource_register_hz/khz sparc: convert to clocksource_register_hz/khz alpha: convert to clocksource_register_hz microblaze: convert to clocksource_register_hz/khz ia64: convert to clocksource_register_hz/khz x86: Convert remaining x86 clocksources to clocksource_register_hz/khz Make clocksource name const
Diffstat (limited to 'arch/x86/kernel')
-rw-r--r--arch/x86/kernel/apb_timer.c10
-rw-r--r--arch/x86/kernel/i8253.c80
-rw-r--r--arch/x86/kernel/kvmclock.c6
3 files changed, 3 insertions, 93 deletions
diff --git a/arch/x86/kernel/apb_timer.c b/arch/x86/kernel/apb_timer.c
index cd1ffed4ee22..289e92862fd9 100644
--- a/arch/x86/kernel/apb_timer.c
+++ b/arch/x86/kernel/apb_timer.c
@@ -177,7 +177,6 @@ static struct clocksource clocksource_apbt = {
177 .rating = APBT_CLOCKSOURCE_RATING, 177 .rating = APBT_CLOCKSOURCE_RATING,
178 .read = apbt_read_clocksource, 178 .read = apbt_read_clocksource,
179 .mask = APBT_MASK, 179 .mask = APBT_MASK,
180 .shift = APBT_SHIFT,
181 .flags = CLOCK_SOURCE_IS_CONTINUOUS, 180 .flags = CLOCK_SOURCE_IS_CONTINUOUS,
182 .resume = apbt_restart_clocksource, 181 .resume = apbt_restart_clocksource,
183}; 182};
@@ -543,14 +542,7 @@ static int apbt_clocksource_register(void)
543 if (t1 == apbt_read_clocksource(&clocksource_apbt)) 542 if (t1 == apbt_read_clocksource(&clocksource_apbt))
544 panic("APBT counter not counting. APBT disabled\n"); 543 panic("APBT counter not counting. APBT disabled\n");
545 544
546 /* 545 clocksource_register_khz(&clocksource_apbt, (u32)apbt_freq*1000);
547 * initialize and register APBT clocksource
548 * convert that to ns/clock cycle
549 * mult = (ns/c) * 2^APBT_SHIFT
550 */
551 clocksource_apbt.mult = div_sc(MSEC_PER_SEC,
552 (unsigned long) apbt_freq, APBT_SHIFT);
553 clocksource_register(&clocksource_apbt);
554 546
555 return 0; 547 return 0;
556} 548}
diff --git a/arch/x86/kernel/i8253.c b/arch/x86/kernel/i8253.c
index 2dfd31597443..577e90cadaeb 100644
--- a/arch/x86/kernel/i8253.c
+++ b/arch/x86/kernel/i8253.c
@@ -117,81 +117,6 @@ void __init setup_pit_timer(void)
117} 117}
118 118
119#ifndef CONFIG_X86_64 119#ifndef CONFIG_X86_64
120/*
121 * Since the PIT overflows every tick, its not very useful
122 * to just read by itself. So use jiffies to emulate a free
123 * running counter:
124 */
125static cycle_t pit_read(struct clocksource *cs)
126{
127 static int old_count;
128 static u32 old_jifs;
129 unsigned long flags;
130 int count;
131 u32 jifs;
132
133 raw_spin_lock_irqsave(&i8253_lock, flags);
134 /*
135 * Although our caller may have the read side of xtime_lock,
136 * this is now a seqlock, and we are cheating in this routine
137 * by having side effects on state that we cannot undo if
138 * there is a collision on the seqlock and our caller has to
139 * retry. (Namely, old_jifs and old_count.) So we must treat
140 * jiffies as volatile despite the lock. We read jiffies
141 * before latching the timer count to guarantee that although
142 * the jiffies value might be older than the count (that is,
143 * the counter may underflow between the last point where
144 * jiffies was incremented and the point where we latch the
145 * count), it cannot be newer.
146 */
147 jifs = jiffies;
148 outb_pit(0x00, PIT_MODE); /* latch the count ASAP */
149 count = inb_pit(PIT_CH0); /* read the latched count */
150 count |= inb_pit(PIT_CH0) << 8;
151
152 /* VIA686a test code... reset the latch if count > max + 1 */
153 if (count > LATCH) {
154 outb_pit(0x34, PIT_MODE);
155 outb_pit(LATCH & 0xff, PIT_CH0);
156 outb_pit(LATCH >> 8, PIT_CH0);
157 count = LATCH - 1;
158 }
159
160 /*
161 * It's possible for count to appear to go the wrong way for a
162 * couple of reasons:
163 *
164 * 1. The timer counter underflows, but we haven't handled the
165 * resulting interrupt and incremented jiffies yet.
166 * 2. Hardware problem with the timer, not giving us continuous time,
167 * the counter does small "jumps" upwards on some Pentium systems,
168 * (see c't 95/10 page 335 for Neptun bug.)
169 *
170 * Previous attempts to handle these cases intelligently were
171 * buggy, so we just do the simple thing now.
172 */
173 if (count > old_count && jifs == old_jifs)
174 count = old_count;
175
176 old_count = count;
177 old_jifs = jifs;
178
179 raw_spin_unlock_irqrestore(&i8253_lock, flags);
180
181 count = (LATCH - 1) - count;
182
183 return (cycle_t)(jifs * LATCH) + count;
184}
185
186static struct clocksource pit_cs = {
187 .name = "pit",
188 .rating = 110,
189 .read = pit_read,
190 .mask = CLOCKSOURCE_MASK(32),
191 .mult = 0,
192 .shift = 20,
193};
194
195static int __init init_pit_clocksource(void) 120static int __init init_pit_clocksource(void)
196{ 121{
197 /* 122 /*
@@ -205,10 +130,7 @@ static int __init init_pit_clocksource(void)
205 pit_ce.mode != CLOCK_EVT_MODE_PERIODIC) 130 pit_ce.mode != CLOCK_EVT_MODE_PERIODIC)
206 return 0; 131 return 0;
207 132
208 pit_cs.mult = clocksource_hz2mult(CLOCK_TICK_RATE, pit_cs.shift); 133 return clocksource_i8253_init();
209
210 return clocksource_register(&pit_cs);
211} 134}
212arch_initcall(init_pit_clocksource); 135arch_initcall(init_pit_clocksource);
213
214#endif /* !CONFIG_X86_64 */ 136#endif /* !CONFIG_X86_64 */
diff --git a/arch/x86/kernel/kvmclock.c b/arch/x86/kernel/kvmclock.c
index f98d3eafe07a..6389a6bca11b 100644
--- a/arch/x86/kernel/kvmclock.c
+++ b/arch/x86/kernel/kvmclock.c
@@ -26,8 +26,6 @@
26#include <asm/x86_init.h> 26#include <asm/x86_init.h>
27#include <asm/reboot.h> 27#include <asm/reboot.h>
28 28
29#define KVM_SCALE 22
30
31static int kvmclock = 1; 29static int kvmclock = 1;
32static int msr_kvm_system_time = MSR_KVM_SYSTEM_TIME; 30static int msr_kvm_system_time = MSR_KVM_SYSTEM_TIME;
33static int msr_kvm_wall_clock = MSR_KVM_WALL_CLOCK; 31static int msr_kvm_wall_clock = MSR_KVM_WALL_CLOCK;
@@ -120,8 +118,6 @@ static struct clocksource kvm_clock = {
120 .read = kvm_clock_get_cycles, 118 .read = kvm_clock_get_cycles,
121 .rating = 400, 119 .rating = 400,
122 .mask = CLOCKSOURCE_MASK(64), 120 .mask = CLOCKSOURCE_MASK(64),
123 .mult = 1 << KVM_SCALE,
124 .shift = KVM_SCALE,
125 .flags = CLOCK_SOURCE_IS_CONTINUOUS, 121 .flags = CLOCK_SOURCE_IS_CONTINUOUS,
126}; 122};
127 123
@@ -203,7 +199,7 @@ void __init kvmclock_init(void)
203 machine_ops.crash_shutdown = kvm_crash_shutdown; 199 machine_ops.crash_shutdown = kvm_crash_shutdown;
204#endif 200#endif
205 kvm_get_preset_lpj(); 201 kvm_get_preset_lpj();
206 clocksource_register(&kvm_clock); 202 clocksource_register_hz(&kvm_clock, NSEC_PER_SEC);
207 pv_info.paravirt_enabled = 1; 203 pv_info.paravirt_enabled = 1;
208 pv_info.name = "KVM"; 204 pv_info.name = "KVM";
209 205