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authorThomas Gleixner <tglx@linutronix.de>2007-10-11 05:17:01 -0400
committerThomas Gleixner <tglx@linutronix.de>2007-10-11 05:17:01 -0400
commit9a163ed8e0552fdcffe405d2ea7134819a81456e (patch)
treeb322fd2afbb812ba7ddfd22f3734aaab007c2aa5 /arch/x86/kernel/vmiclock_32.c
parentf7627e2513987bb5d4e8cb13c4e0a478352141ac (diff)
i386: move kernel
Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Signed-off-by: Ingo Molnar <mingo@elte.hu>
Diffstat (limited to 'arch/x86/kernel/vmiclock_32.c')
-rw-r--r--arch/x86/kernel/vmiclock_32.c320
1 files changed, 320 insertions, 0 deletions
diff --git a/arch/x86/kernel/vmiclock_32.c b/arch/x86/kernel/vmiclock_32.c
new file mode 100644
index 000000000000..b1b5ab08b26e
--- /dev/null
+++ b/arch/x86/kernel/vmiclock_32.c
@@ -0,0 +1,320 @@
1/*
2 * VMI paravirtual timer support routines.
3 *
4 * Copyright (C) 2007, VMware, Inc.
5 *
6 * This program is free software; you can redistribute it and/or modify
7 * it under the terms of the GNU General Public License as published by
8 * the Free Software Foundation; either version 2 of the License, or
9 * (at your option) any later version.
10 *
11 * This program is distributed in the hope that it will be useful, but
12 * WITHOUT ANY WARRANTY; without even the implied warranty of
13 * MERCHANTABILITY OR FITNESS FOR A PARTICULAR PURPOSE, GOOD TITLE or
14 * NON INFRINGEMENT. See the GNU General Public License for more
15 * details.
16 *
17 * You should have received a copy of the GNU General Public License
18 * along with this program; if not, write to the Free Software
19 * Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.
20 *
21 */
22
23#include <linux/smp.h>
24#include <linux/interrupt.h>
25#include <linux/cpumask.h>
26#include <linux/clocksource.h>
27#include <linux/clockchips.h>
28
29#include <asm/vmi.h>
30#include <asm/vmi_time.h>
31#include <asm/arch_hooks.h>
32#include <asm/apicdef.h>
33#include <asm/apic.h>
34#include <asm/timer.h>
35#include <asm/i8253.h>
36
37#include <irq_vectors.h>
38#include "io_ports.h"
39
40#define VMI_ONESHOT (VMI_ALARM_IS_ONESHOT | VMI_CYCLES_REAL | vmi_get_alarm_wiring())
41#define VMI_PERIODIC (VMI_ALARM_IS_PERIODIC | VMI_CYCLES_REAL | vmi_get_alarm_wiring())
42
43static DEFINE_PER_CPU(struct clock_event_device, local_events);
44
45static inline u32 vmi_counter(u32 flags)
46{
47 /* Given VMI_ONESHOT or VMI_PERIODIC, return the corresponding
48 * cycle counter. */
49 return flags & VMI_ALARM_COUNTER_MASK;
50}
51
52/* paravirt_ops.get_wallclock = vmi_get_wallclock */
53unsigned long vmi_get_wallclock(void)
54{
55 unsigned long long wallclock;
56 wallclock = vmi_timer_ops.get_wallclock(); // nsec
57 (void)do_div(wallclock, 1000000000); // sec
58
59 return wallclock;
60}
61
62/* paravirt_ops.set_wallclock = vmi_set_wallclock */
63int vmi_set_wallclock(unsigned long now)
64{
65 return 0;
66}
67
68/* paravirt_ops.sched_clock = vmi_sched_clock */
69unsigned long long vmi_sched_clock(void)
70{
71 return cycles_2_ns(vmi_timer_ops.get_cycle_counter(VMI_CYCLES_AVAILABLE));
72}
73
74/* paravirt_ops.get_cpu_khz = vmi_cpu_khz */
75unsigned long vmi_cpu_khz(void)
76{
77 unsigned long long khz;
78 khz = vmi_timer_ops.get_cycle_frequency();
79 (void)do_div(khz, 1000);
80 return khz;
81}
82
83static inline unsigned int vmi_get_timer_vector(void)
84{
85#ifdef CONFIG_X86_IO_APIC
86 return FIRST_DEVICE_VECTOR;
87#else
88 return FIRST_EXTERNAL_VECTOR;
89#endif
90}
91
92/** vmi clockchip */
93#ifdef CONFIG_X86_LOCAL_APIC
94static unsigned int startup_timer_irq(unsigned int irq)
95{
96 unsigned long val = apic_read(APIC_LVTT);
97 apic_write(APIC_LVTT, vmi_get_timer_vector());
98
99 return (val & APIC_SEND_PENDING);
100}
101
102static void mask_timer_irq(unsigned int irq)
103{
104 unsigned long val = apic_read(APIC_LVTT);
105 apic_write(APIC_LVTT, val | APIC_LVT_MASKED);
106}
107
108static void unmask_timer_irq(unsigned int irq)
109{
110 unsigned long val = apic_read(APIC_LVTT);
111 apic_write(APIC_LVTT, val & ~APIC_LVT_MASKED);
112}
113
114static void ack_timer_irq(unsigned int irq)
115{
116 ack_APIC_irq();
117}
118
119static struct irq_chip vmi_chip __read_mostly = {
120 .name = "VMI-LOCAL",
121 .startup = startup_timer_irq,
122 .mask = mask_timer_irq,
123 .unmask = unmask_timer_irq,
124 .ack = ack_timer_irq
125};
126#endif
127
128/** vmi clockevent */
129#define VMI_ALARM_WIRED_IRQ0 0x00000000
130#define VMI_ALARM_WIRED_LVTT 0x00010000
131static int vmi_wiring = VMI_ALARM_WIRED_IRQ0;
132
133static inline int vmi_get_alarm_wiring(void)
134{
135 return vmi_wiring;
136}
137
138static void vmi_timer_set_mode(enum clock_event_mode mode,
139 struct clock_event_device *evt)
140{
141 cycle_t now, cycles_per_hz;
142 BUG_ON(!irqs_disabled());
143
144 switch (mode) {
145 case CLOCK_EVT_MODE_ONESHOT:
146 case CLOCK_EVT_MODE_RESUME:
147 break;
148 case CLOCK_EVT_MODE_PERIODIC:
149 cycles_per_hz = vmi_timer_ops.get_cycle_frequency();
150 (void)do_div(cycles_per_hz, HZ);
151 now = vmi_timer_ops.get_cycle_counter(vmi_counter(VMI_PERIODIC));
152 vmi_timer_ops.set_alarm(VMI_PERIODIC, now, cycles_per_hz);
153 break;
154 case CLOCK_EVT_MODE_UNUSED:
155 case CLOCK_EVT_MODE_SHUTDOWN:
156 switch (evt->mode) {
157 case CLOCK_EVT_MODE_ONESHOT:
158 vmi_timer_ops.cancel_alarm(VMI_ONESHOT);
159 break;
160 case CLOCK_EVT_MODE_PERIODIC:
161 vmi_timer_ops.cancel_alarm(VMI_PERIODIC);
162 break;
163 default:
164 break;
165 }
166 break;
167 default:
168 break;
169 }
170}
171
172static int vmi_timer_next_event(unsigned long delta,
173 struct clock_event_device *evt)
174{
175 /* Unfortunately, set_next_event interface only passes relative
176 * expiry, but we want absolute expiry. It'd be better if were
177 * were passed an aboslute expiry, since a bunch of time may
178 * have been stolen between the time the delta is computed and
179 * when we set the alarm below. */
180 cycle_t now = vmi_timer_ops.get_cycle_counter(vmi_counter(VMI_ONESHOT));
181
182 BUG_ON(evt->mode != CLOCK_EVT_MODE_ONESHOT);
183 vmi_timer_ops.set_alarm(VMI_ONESHOT, now + delta, 0);
184 return 0;
185}
186
187static struct clock_event_device vmi_clockevent = {
188 .name = "vmi-timer",
189 .features = CLOCK_EVT_FEAT_PERIODIC | CLOCK_EVT_FEAT_ONESHOT,
190 .shift = 22,
191 .set_mode = vmi_timer_set_mode,
192 .set_next_event = vmi_timer_next_event,
193 .rating = 1000,
194 .irq = 0,
195};
196
197static irqreturn_t vmi_timer_interrupt(int irq, void *dev_id)
198{
199 struct clock_event_device *evt = &__get_cpu_var(local_events);
200 evt->event_handler(evt);
201 return IRQ_HANDLED;
202}
203
204static struct irqaction vmi_clock_action = {
205 .name = "vmi-timer",
206 .handler = vmi_timer_interrupt,
207 .flags = IRQF_DISABLED | IRQF_NOBALANCING,
208 .mask = CPU_MASK_ALL,
209};
210
211static void __devinit vmi_time_init_clockevent(void)
212{
213 cycle_t cycles_per_msec;
214 struct clock_event_device *evt;
215
216 int cpu = smp_processor_id();
217 evt = &__get_cpu_var(local_events);
218
219 /* Use cycles_per_msec since div_sc params are 32-bits. */
220 cycles_per_msec = vmi_timer_ops.get_cycle_frequency();
221 (void)do_div(cycles_per_msec, 1000);
222
223 memcpy(evt, &vmi_clockevent, sizeof(*evt));
224 /* Must pick .shift such that .mult fits in 32-bits. Choosing
225 * .shift to be 22 allows 2^(32-22) cycles per nano-seconds
226 * before overflow. */
227 evt->mult = div_sc(cycles_per_msec, NSEC_PER_MSEC, evt->shift);
228 /* Upper bound is clockevent's use of ulong for cycle deltas. */
229 evt->max_delta_ns = clockevent_delta2ns(ULONG_MAX, evt);
230 evt->min_delta_ns = clockevent_delta2ns(1, evt);
231 evt->cpumask = cpumask_of_cpu(cpu);
232
233 printk(KERN_WARNING "vmi: registering clock event %s. mult=%lu shift=%u\n",
234 evt->name, evt->mult, evt->shift);
235 clockevents_register_device(evt);
236}
237
238void __init vmi_time_init(void)
239{
240 /* Disable PIT: BIOSes start PIT CH0 with 18.2hz peridic. */
241 outb_p(0x3a, PIT_MODE); /* binary, mode 5, LSB/MSB, ch 0 */
242
243 vmi_time_init_clockevent();
244 setup_irq(0, &vmi_clock_action);
245}
246
247#ifdef CONFIG_X86_LOCAL_APIC
248void __devinit vmi_time_bsp_init(void)
249{
250 /*
251 * On APIC systems, we want local timers to fire on each cpu. We do
252 * this by programming LVTT to deliver timer events to the IRQ handler
253 * for IRQ-0, since we can't re-use the APIC local timer handler
254 * without interfering with that code.
255 */
256 clockevents_notify(CLOCK_EVT_NOTIFY_SUSPEND, NULL);
257 local_irq_disable();
258#ifdef CONFIG_X86_SMP
259 /*
260 * XXX handle_percpu_irq only defined for SMP; we need to switch over
261 * to using it, since this is a local interrupt, which each CPU must
262 * handle individually without locking out or dropping simultaneous
263 * local timers on other CPUs. We also don't want to trigger the
264 * quirk workaround code for interrupts which gets invoked from
265 * handle_percpu_irq via eoi, so we use our own IRQ chip.
266 */
267 set_irq_chip_and_handler_name(0, &vmi_chip, handle_percpu_irq, "lvtt");
268#else
269 set_irq_chip_and_handler_name(0, &vmi_chip, handle_edge_irq, "lvtt");
270#endif
271 vmi_wiring = VMI_ALARM_WIRED_LVTT;
272 apic_write(APIC_LVTT, vmi_get_timer_vector());
273 local_irq_enable();
274 clockevents_notify(CLOCK_EVT_NOTIFY_RESUME, NULL);
275}
276
277void __devinit vmi_time_ap_init(void)
278{
279 vmi_time_init_clockevent();
280 apic_write(APIC_LVTT, vmi_get_timer_vector());
281}
282#endif
283
284/** vmi clocksource */
285
286static cycle_t read_real_cycles(void)
287{
288 return vmi_timer_ops.get_cycle_counter(VMI_CYCLES_REAL);
289}
290
291static struct clocksource clocksource_vmi = {
292 .name = "vmi-timer",
293 .rating = 450,
294 .read = read_real_cycles,
295 .mask = CLOCKSOURCE_MASK(64),
296 .mult = 0, /* to be set */
297 .shift = 22,
298 .flags = CLOCK_SOURCE_IS_CONTINUOUS,
299};
300
301static int __init init_vmi_clocksource(void)
302{
303 cycle_t cycles_per_msec;
304
305 if (!vmi_timer_ops.get_cycle_frequency)
306 return 0;
307 /* Use khz2mult rather than hz2mult since hz arg is only 32-bits. */
308 cycles_per_msec = vmi_timer_ops.get_cycle_frequency();
309 (void)do_div(cycles_per_msec, 1000);
310
311 /* Note that clocksource.{mult, shift} converts in the opposite direction
312 * as clockevents. */
313 clocksource_vmi.mult = clocksource_khz2mult(cycles_per_msec,
314 clocksource_vmi.shift);
315
316 printk(KERN_WARNING "vmi: registering clock source khz=%lld\n", cycles_per_msec);
317 return clocksource_register(&clocksource_vmi);
318
319}
320module_init(init_vmi_clocksource);