diff options
author | Linus Torvalds <torvalds@linux-foundation.org> | 2008-10-23 11:07:35 -0400 |
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committer | Linus Torvalds <torvalds@linux-foundation.org> | 2008-10-23 11:07:35 -0400 |
commit | 72441bdc76f7f71d7b75cdaa48f26dbb1f3d932e (patch) | |
tree | df818d5e210c0c31c6634d43401d02a99ee87d1b /arch/ia64/xen/time.c | |
parent | 2515ddc6db8eb49a79f0fe5e67ff09ac7c81eab4 (diff) | |
parent | fe393164c529f72def1952fb66c11732d0984d78 (diff) |
Merge branch 'release' of git://git.kernel.org/pub/scm/linux/kernel/git/aegl/linux-2.6
* 'release' of git://git.kernel.org/pub/scm/linux/kernel/git/aegl/linux-2.6: (41 commits)
[IA64] Fix annoying IA64_TR_ALLOC_MAX message.
[IA64] kill sys32_pipe
[IA64] remove sys32_pause
[IA64] Add Variable Page Size and IA64 Support in Intel IOMMU
ia64/pv_ops: paravirtualized instruction checker.
ia64/xen: a recipe for using xen/ia64 with pv_ops.
ia64/pv_ops: update Kconfig for paravirtualized guest and xen.
ia64/xen: preliminary support for save/restore.
ia64/xen: define xen machine vector for domU.
ia64/pv_ops/xen: implement xen pv_time_ops.
ia64/pv_ops/xen: implement xen pv_irq_ops.
ia64/pv_ops/xen: define the nubmer of irqs which xen needs.
ia64/pv_ops/xen: implement xen pv_iosapic_ops.
ia64/pv_ops/xen: paravirtualize entry.S for ia64/xen.
ia64/pv_ops/xen: paravirtualize ivt.S for xen.
ia64/pv_ops/xen: paravirtualize DO_SAVE_MIN for xen.
ia64/pv_ops/xen: define xen paravirtualized instructions for hand written assembly code
ia64/pv_ops/xen: define xen pv_cpu_ops.
ia64/pv_ops/xen: define xen pv_init_ops for various xen initialization.
ia64/pv_ops/xen: elf note based xen startup.
...
Diffstat (limited to 'arch/ia64/xen/time.c')
-rw-r--r-- | arch/ia64/xen/time.c | 213 |
1 files changed, 213 insertions, 0 deletions
diff --git a/arch/ia64/xen/time.c b/arch/ia64/xen/time.c new file mode 100644 index 000000000000..d15a94c330fb --- /dev/null +++ b/arch/ia64/xen/time.c | |||
@@ -0,0 +1,213 @@ | |||
1 | /****************************************************************************** | ||
2 | * arch/ia64/xen/time.c | ||
3 | * | ||
4 | * Copyright (c) 2008 Isaku Yamahata <yamahata at valinux co jp> | ||
5 | * VA Linux Systems Japan K.K. | ||
6 | * | ||
7 | * This program is free software; you can redistribute it and/or modify | ||
8 | * it under the terms of the GNU General Public License as published by | ||
9 | * the Free Software Foundation; either version 2 of the License, or | ||
10 | * (at your option) any later version. | ||
11 | * | ||
12 | * This program is distributed in the hope that it will be useful, | ||
13 | * but WITHOUT ANY WARRANTY; without even the implied warranty of | ||
14 | * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the | ||
15 | * GNU General Public License for more 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., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA | ||
20 | * | ||
21 | */ | ||
22 | |||
23 | #include <linux/delay.h> | ||
24 | #include <linux/kernel_stat.h> | ||
25 | #include <linux/posix-timers.h> | ||
26 | #include <linux/irq.h> | ||
27 | #include <linux/clocksource.h> | ||
28 | |||
29 | #include <asm/timex.h> | ||
30 | |||
31 | #include <asm/xen/hypervisor.h> | ||
32 | |||
33 | #include <xen/interface/vcpu.h> | ||
34 | |||
35 | #include "../kernel/fsyscall_gtod_data.h" | ||
36 | |||
37 | DEFINE_PER_CPU(struct vcpu_runstate_info, runstate); | ||
38 | DEFINE_PER_CPU(unsigned long, processed_stolen_time); | ||
39 | DEFINE_PER_CPU(unsigned long, processed_blocked_time); | ||
40 | |||
41 | /* taken from i386/kernel/time-xen.c */ | ||
42 | static void xen_init_missing_ticks_accounting(int cpu) | ||
43 | { | ||
44 | struct vcpu_register_runstate_memory_area area; | ||
45 | struct vcpu_runstate_info *runstate = &per_cpu(runstate, cpu); | ||
46 | int rc; | ||
47 | |||
48 | memset(runstate, 0, sizeof(*runstate)); | ||
49 | |||
50 | area.addr.v = runstate; | ||
51 | rc = HYPERVISOR_vcpu_op(VCPUOP_register_runstate_memory_area, cpu, | ||
52 | &area); | ||
53 | WARN_ON(rc && rc != -ENOSYS); | ||
54 | |||
55 | per_cpu(processed_blocked_time, cpu) = runstate->time[RUNSTATE_blocked]; | ||
56 | per_cpu(processed_stolen_time, cpu) = runstate->time[RUNSTATE_runnable] | ||
57 | + runstate->time[RUNSTATE_offline]; | ||
58 | } | ||
59 | |||
60 | /* | ||
61 | * Runstate accounting | ||
62 | */ | ||
63 | /* stolen from arch/x86/xen/time.c */ | ||
64 | static void get_runstate_snapshot(struct vcpu_runstate_info *res) | ||
65 | { | ||
66 | u64 state_time; | ||
67 | struct vcpu_runstate_info *state; | ||
68 | |||
69 | BUG_ON(preemptible()); | ||
70 | |||
71 | state = &__get_cpu_var(runstate); | ||
72 | |||
73 | /* | ||
74 | * The runstate info is always updated by the hypervisor on | ||
75 | * the current CPU, so there's no need to use anything | ||
76 | * stronger than a compiler barrier when fetching it. | ||
77 | */ | ||
78 | do { | ||
79 | state_time = state->state_entry_time; | ||
80 | rmb(); | ||
81 | *res = *state; | ||
82 | rmb(); | ||
83 | } while (state->state_entry_time != state_time); | ||
84 | } | ||
85 | |||
86 | #define NS_PER_TICK (1000000000LL/HZ) | ||
87 | |||
88 | static unsigned long | ||
89 | consider_steal_time(unsigned long new_itm) | ||
90 | { | ||
91 | unsigned long stolen, blocked; | ||
92 | unsigned long delta_itm = 0, stolentick = 0; | ||
93 | int cpu = smp_processor_id(); | ||
94 | struct vcpu_runstate_info runstate; | ||
95 | struct task_struct *p = current; | ||
96 | |||
97 | get_runstate_snapshot(&runstate); | ||
98 | |||
99 | /* | ||
100 | * Check for vcpu migration effect | ||
101 | * In this case, itc value is reversed. | ||
102 | * This causes huge stolen value. | ||
103 | * This function just checks and reject this effect. | ||
104 | */ | ||
105 | if (!time_after_eq(runstate.time[RUNSTATE_blocked], | ||
106 | per_cpu(processed_blocked_time, cpu))) | ||
107 | blocked = 0; | ||
108 | |||
109 | if (!time_after_eq(runstate.time[RUNSTATE_runnable] + | ||
110 | runstate.time[RUNSTATE_offline], | ||
111 | per_cpu(processed_stolen_time, cpu))) | ||
112 | stolen = 0; | ||
113 | |||
114 | if (!time_after(delta_itm + new_itm, ia64_get_itc())) | ||
115 | stolentick = ia64_get_itc() - new_itm; | ||
116 | |||
117 | do_div(stolentick, NS_PER_TICK); | ||
118 | stolentick++; | ||
119 | |||
120 | do_div(stolen, NS_PER_TICK); | ||
121 | |||
122 | if (stolen > stolentick) | ||
123 | stolen = stolentick; | ||
124 | |||
125 | stolentick -= stolen; | ||
126 | do_div(blocked, NS_PER_TICK); | ||
127 | |||
128 | if (blocked > stolentick) | ||
129 | blocked = stolentick; | ||
130 | |||
131 | if (stolen > 0 || blocked > 0) { | ||
132 | account_steal_time(NULL, jiffies_to_cputime(stolen)); | ||
133 | account_steal_time(idle_task(cpu), jiffies_to_cputime(blocked)); | ||
134 | run_local_timers(); | ||
135 | |||
136 | if (rcu_pending(cpu)) | ||
137 | rcu_check_callbacks(cpu, user_mode(get_irq_regs())); | ||
138 | |||
139 | scheduler_tick(); | ||
140 | run_posix_cpu_timers(p); | ||
141 | delta_itm += local_cpu_data->itm_delta * (stolen + blocked); | ||
142 | |||
143 | if (cpu == time_keeper_id) { | ||
144 | write_seqlock(&xtime_lock); | ||
145 | do_timer(stolen + blocked); | ||
146 | local_cpu_data->itm_next = delta_itm + new_itm; | ||
147 | write_sequnlock(&xtime_lock); | ||
148 | } else { | ||
149 | local_cpu_data->itm_next = delta_itm + new_itm; | ||
150 | } | ||
151 | per_cpu(processed_stolen_time, cpu) += NS_PER_TICK * stolen; | ||
152 | per_cpu(processed_blocked_time, cpu) += NS_PER_TICK * blocked; | ||
153 | } | ||
154 | return delta_itm; | ||
155 | } | ||
156 | |||
157 | static int xen_do_steal_accounting(unsigned long *new_itm) | ||
158 | { | ||
159 | unsigned long delta_itm; | ||
160 | delta_itm = consider_steal_time(*new_itm); | ||
161 | *new_itm += delta_itm; | ||
162 | if (time_after(*new_itm, ia64_get_itc()) && delta_itm) | ||
163 | return 1; | ||
164 | |||
165 | return 0; | ||
166 | } | ||
167 | |||
168 | static void xen_itc_jitter_data_reset(void) | ||
169 | { | ||
170 | u64 lcycle, ret; | ||
171 | |||
172 | do { | ||
173 | lcycle = itc_jitter_data.itc_lastcycle; | ||
174 | ret = cmpxchg(&itc_jitter_data.itc_lastcycle, lcycle, 0); | ||
175 | } while (unlikely(ret != lcycle)); | ||
176 | } | ||
177 | |||
178 | struct pv_time_ops xen_time_ops __initdata = { | ||
179 | .init_missing_ticks_accounting = xen_init_missing_ticks_accounting, | ||
180 | .do_steal_accounting = xen_do_steal_accounting, | ||
181 | .clocksource_resume = xen_itc_jitter_data_reset, | ||
182 | }; | ||
183 | |||
184 | /* Called after suspend, to resume time. */ | ||
185 | static void xen_local_tick_resume(void) | ||
186 | { | ||
187 | /* Just trigger a tick. */ | ||
188 | ia64_cpu_local_tick(); | ||
189 | touch_softlockup_watchdog(); | ||
190 | } | ||
191 | |||
192 | void | ||
193 | xen_timer_resume(void) | ||
194 | { | ||
195 | unsigned int cpu; | ||
196 | |||
197 | xen_local_tick_resume(); | ||
198 | |||
199 | for_each_online_cpu(cpu) | ||
200 | xen_init_missing_ticks_accounting(cpu); | ||
201 | } | ||
202 | |||
203 | static void ia64_cpu_local_tick_fn(void *unused) | ||
204 | { | ||
205 | xen_local_tick_resume(); | ||
206 | xen_init_missing_ticks_accounting(smp_processor_id()); | ||
207 | } | ||
208 | |||
209 | void | ||
210 | xen_timer_resume_on_aps(void) | ||
211 | { | ||
212 | smp_call_function(&ia64_cpu_local_tick_fn, NULL, 1); | ||
213 | } | ||