diff options
author | Linus Torvalds <torvalds@ppc970.osdl.org> | 2005-04-16 18:20:36 -0400 |
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committer | Linus Torvalds <torvalds@ppc970.osdl.org> | 2005-04-16 18:20:36 -0400 |
commit | 1da177e4c3f41524e886b7f1b8a0c1fc7321cac2 (patch) | |
tree | 0bba044c4ce775e45a88a51686b5d9f90697ea9d /include/asm-i386/mach-default/do_timer.h |
Linux-2.6.12-rc2v2.6.12-rc2
Initial git repository build. I'm not bothering with the full history,
even though we have it. We can create a separate "historical" git
archive of that later if we want to, and in the meantime it's about
3.2GB when imported into git - space that would just make the early
git days unnecessarily complicated, when we don't have a lot of good
infrastructure for it.
Let it rip!
Diffstat (limited to 'include/asm-i386/mach-default/do_timer.h')
-rw-r--r-- | include/asm-i386/mach-default/do_timer.h | 85 |
1 files changed, 85 insertions, 0 deletions
diff --git a/include/asm-i386/mach-default/do_timer.h b/include/asm-i386/mach-default/do_timer.h new file mode 100644 index 000000000000..03dd13a48a8c --- /dev/null +++ b/include/asm-i386/mach-default/do_timer.h | |||
@@ -0,0 +1,85 @@ | |||
1 | /* defines for inline arch setup functions */ | ||
2 | |||
3 | #include <asm/apic.h> | ||
4 | |||
5 | /** | ||
6 | * do_timer_interrupt_hook - hook into timer tick | ||
7 | * @regs: standard registers from interrupt | ||
8 | * | ||
9 | * Description: | ||
10 | * This hook is called immediately after the timer interrupt is ack'd. | ||
11 | * It's primary purpose is to allow architectures that don't possess | ||
12 | * individual per CPU clocks (like the CPU APICs supply) to broadcast the | ||
13 | * timer interrupt as a means of triggering reschedules etc. | ||
14 | **/ | ||
15 | |||
16 | static inline void do_timer_interrupt_hook(struct pt_regs *regs) | ||
17 | { | ||
18 | do_timer(regs); | ||
19 | #ifndef CONFIG_SMP | ||
20 | update_process_times(user_mode(regs)); | ||
21 | #endif | ||
22 | /* | ||
23 | * In the SMP case we use the local APIC timer interrupt to do the | ||
24 | * profiling, except when we simulate SMP mode on a uniprocessor | ||
25 | * system, in that case we have to call the local interrupt handler. | ||
26 | */ | ||
27 | #ifndef CONFIG_X86_LOCAL_APIC | ||
28 | profile_tick(CPU_PROFILING, regs); | ||
29 | #else | ||
30 | if (!using_apic_timer) | ||
31 | smp_local_timer_interrupt(regs); | ||
32 | #endif | ||
33 | } | ||
34 | |||
35 | |||
36 | /* you can safely undefine this if you don't have the Neptune chipset */ | ||
37 | |||
38 | #define BUGGY_NEPTUN_TIMER | ||
39 | |||
40 | /** | ||
41 | * do_timer_overflow - process a detected timer overflow condition | ||
42 | * @count: hardware timer interrupt count on overflow | ||
43 | * | ||
44 | * Description: | ||
45 | * This call is invoked when the jiffies count has not incremented but | ||
46 | * the hardware timer interrupt has. It means that a timer tick interrupt | ||
47 | * came along while the previous one was pending, thus a tick was missed | ||
48 | **/ | ||
49 | static inline int do_timer_overflow(int count) | ||
50 | { | ||
51 | int i; | ||
52 | |||
53 | spin_lock(&i8259A_lock); | ||
54 | /* | ||
55 | * This is tricky when I/O APICs are used; | ||
56 | * see do_timer_interrupt(). | ||
57 | */ | ||
58 | i = inb(0x20); | ||
59 | spin_unlock(&i8259A_lock); | ||
60 | |||
61 | /* assumption about timer being IRQ0 */ | ||
62 | if (i & 0x01) { | ||
63 | /* | ||
64 | * We cannot detect lost timer interrupts ... | ||
65 | * well, that's why we call them lost, don't we? :) | ||
66 | * [hmm, on the Pentium and Alpha we can ... sort of] | ||
67 | */ | ||
68 | count -= LATCH; | ||
69 | } else { | ||
70 | #ifdef BUGGY_NEPTUN_TIMER | ||
71 | /* | ||
72 | * for the Neptun bug we know that the 'latch' | ||
73 | * command doesn't latch the high and low value | ||
74 | * of the counter atomically. Thus we have to | ||
75 | * substract 256 from the counter | ||
76 | * ... funny, isnt it? :) | ||
77 | */ | ||
78 | |||
79 | count -= 256; | ||
80 | #else | ||
81 | printk("do_slow_gettimeoffset(): hardware timer problem?\n"); | ||
82 | #endif | ||
83 | } | ||
84 | return count; | ||
85 | } | ||