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authorLinus Torvalds <torvalds@linux-foundation.org>2009-03-28 23:40:20 +0300
committerLinus Torvalds <torvalds@linux-foundation.org>2009-03-28 23:48:38 +0300
commit7c730ccdc1188b97f5c8cb690906242c7ed75c22 (patch)
tree17ccd927e70dadaf59104c53cce892474eb539b2 /arch/x86/include/asm/mach_timer.h
parent8d735b4148d46446e64d72b22ef0344ee8dc02fa (diff)
parent82268da1b130f763d22d04f7d016bbf6fc8815c2 (diff)
downloadlinux-7c730ccdc1188b97f5c8cb690906242c7ed75c22.tar.xz
Merge branch 'percpu-cpumask-x86-for-linus-2' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/linux-2.6-tip
* 'percpu-cpumask-x86-for-linus-2' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/linux-2.6-tip: (682 commits) percpu: fix spurious alignment WARN in legacy SMP percpu allocator percpu: generalize embedding first chunk setup helper percpu: more flexibility for @dyn_size of pcpu_setup_first_chunk() percpu: make x86 addr <-> pcpu ptr conversion macros generic linker script: define __per_cpu_load on all SMP capable archs x86: UV: remove uv_flush_tlb_others() WARN_ON percpu: finer grained locking to break deadlock and allow atomic free percpu: move fully free chunk reclamation into a work percpu: move chunk area map extension out of area allocation percpu: replace pcpu_realloc() with pcpu_mem_alloc() and pcpu_mem_free() x86, percpu: setup reserved percpu area for x86_64 percpu, module: implement reserved allocation and use it for module percpu variables percpu: add an indirection ptr for chunk page map access x86: make embedding percpu allocator return excessive free space percpu: use negative for auto for pcpu_setup_first_chunk() arguments percpu: improve first chunk initial area map handling percpu: cosmetic renames in pcpu_setup_first_chunk() percpu: clean up percpu constants x86: un-__init fill_pud/pmd/pte x86: remove vestigial fix_ioremap prototypes ... Manually merge conflicts in arch/ia64/kernel/irq_ia64.c
Diffstat (limited to 'arch/x86/include/asm/mach_timer.h')
-rw-r--r--arch/x86/include/asm/mach_timer.h48
1 files changed, 48 insertions, 0 deletions
diff --git a/arch/x86/include/asm/mach_timer.h b/arch/x86/include/asm/mach_timer.h
new file mode 100644
index 000000000000..853728519ae9
--- /dev/null
+++ b/arch/x86/include/asm/mach_timer.h
@@ -0,0 +1,48 @@
+/*
+ * Machine specific calibrate_tsc() for generic.
+ * Split out from timer_tsc.c by Osamu Tomita <tomita@cinet.co.jp>
+ */
+/* ------ Calibrate the TSC -------
+ * Return 2^32 * (1 / (TSC clocks per usec)) for do_fast_gettimeoffset().
+ * Too much 64-bit arithmetic here to do this cleanly in C, and for
+ * accuracy's sake we want to keep the overhead on the CTC speaker (channel 2)
+ * output busy loop as low as possible. We avoid reading the CTC registers
+ * directly because of the awkward 8-bit access mechanism of the 82C54
+ * device.
+ */
+#ifndef _ASM_X86_MACH_DEFAULT_MACH_TIMER_H
+#define _ASM_X86_MACH_DEFAULT_MACH_TIMER_H
+
+#define CALIBRATE_TIME_MSEC 30 /* 30 msecs */
+#define CALIBRATE_LATCH \
+ ((CLOCK_TICK_RATE * CALIBRATE_TIME_MSEC + 1000/2)/1000)
+
+static inline void mach_prepare_counter(void)
+{
+ /* Set the Gate high, disable speaker */
+ outb((inb(0x61) & ~0x02) | 0x01, 0x61);
+
+ /*
+ * Now let's take care of CTC channel 2
+ *
+ * Set the Gate high, program CTC channel 2 for mode 0,
+ * (interrupt on terminal count mode), binary count,
+ * load 5 * LATCH count, (LSB and MSB) to begin countdown.
+ *
+ * Some devices need a delay here.
+ */
+ outb(0xb0, 0x43); /* binary, mode 0, LSB/MSB, Ch 2 */
+ outb_p(CALIBRATE_LATCH & 0xff, 0x42); /* LSB of count */
+ outb_p(CALIBRATE_LATCH >> 8, 0x42); /* MSB of count */
+}
+
+static inline void mach_countup(unsigned long *count_p)
+{
+ unsigned long count = 0;
+ do {
+ count++;
+ } while ((inb_p(0x61) & 0x20) == 0);
+ *count_p = count;
+}
+
+#endif /* _ASM_X86_MACH_DEFAULT_MACH_TIMER_H */