summaryrefslogtreecommitdiffstats
path: root/include/linux/jiffies.h
diff options
context:
space:
mode:
authorBjorn Helgaas <bhelgaas@google.com>2012-09-13 08:41:01 -0600
committerBjorn Helgaas <bhelgaas@google.com>2012-09-13 08:41:01 -0600
commit78890b5989d96ddce989cde929c45ceeded0fcaf (patch)
tree4e2da81fc7c97f11aee174b1eedac110c9a68b3a /include/linux/jiffies.h
parent1959ec5f82acbdf91425b41600f119ebecb5f6a8 (diff)
parent55d512e245bc7699a8800e23df1a24195dd08217 (diff)
downloadblackbird-op-linux-78890b5989d96ddce989cde929c45ceeded0fcaf.tar.gz
blackbird-op-linux-78890b5989d96ddce989cde929c45ceeded0fcaf.zip
Merge commit 'v3.6-rc5' into next
* commit 'v3.6-rc5': (1098 commits) Linux 3.6-rc5 HID: tpkbd: work even if the new Lenovo Keyboard driver is not configured Remove user-triggerable BUG from mpol_to_str xen/pciback: Fix proper FLR steps. uml: fix compile error in deliver_alarm() dj: memory scribble in logi_dj Fix order of arguments to compat_put_time[spec|val] xen: Use correct masking in xen_swiotlb_alloc_coherent. xen: fix logical error in tlb flushing xen/p2m: Fix one-off error in checking the P2M tree directory. powerpc: Don't use __put_user() in patch_instruction powerpc: Make sure IPI handlers see data written by IPI senders powerpc: Restore correct DSCR in context switch powerpc: Fix DSCR inheritance in copy_thread() powerpc: Keep thread.dscr and thread.dscr_inherit in sync powerpc: Update DSCR on all CPUs when writing sysfs dscr_default powerpc/powernv: Always go into nap mode when CPU is offline powerpc: Give hypervisor decrementer interrupts their own handler powerpc/vphn: Fix arch_update_cpu_topology() return value ARM: gemini: fix the gemini build ... Conflicts: drivers/net/ethernet/broadcom/bnx2x/bnx2x_main.c drivers/rapidio/devices/tsi721.c
Diffstat (limited to 'include/linux/jiffies.h')
-rw-r--r--include/linux/jiffies.h29
1 files changed, 19 insertions, 10 deletions
diff --git a/include/linux/jiffies.h b/include/linux/jiffies.h
index 265e2c3cbd1c..82680541576d 100644
--- a/include/linux/jiffies.h
+++ b/include/linux/jiffies.h
@@ -39,9 +39,6 @@
# error Invalid value of HZ.
#endif
-/* LATCH is used in the interval timer and ftape setup. */
-#define LATCH ((CLOCK_TICK_RATE + HZ/2) / HZ) /* For divider */
-
/* Suppose we want to divide two numbers NOM and DEN: NOM/DEN, then we can
* improve accuracy by shifting LSH bits, hence calculating:
* (NOM << LSH) / DEN
@@ -54,18 +51,30 @@
#define SH_DIV(NOM,DEN,LSH) ( (((NOM) / (DEN)) << (LSH)) \
+ ((((NOM) % (DEN)) << (LSH)) + (DEN) / 2) / (DEN))
-/* HZ is the requested value. ACTHZ is actual HZ ("<< 8" is for accuracy) */
-#define ACTHZ (SH_DIV (CLOCK_TICK_RATE, LATCH, 8))
+#ifdef CLOCK_TICK_RATE
+/* LATCH is used in the interval timer and ftape setup. */
+# define LATCH ((CLOCK_TICK_RATE + HZ/2) / HZ) /* For divider */
+
+/*
+ * HZ is the requested value. However the CLOCK_TICK_RATE may not allow
+ * for exactly HZ. So SHIFTED_HZ is high res HZ ("<< 8" is for accuracy)
+ */
+# define SHIFTED_HZ (SH_DIV(CLOCK_TICK_RATE, LATCH, 8))
+#else
+# define SHIFTED_HZ (HZ << 8)
+#endif
-/* TICK_NSEC is the time between ticks in nsec assuming real ACTHZ */
-#define TICK_NSEC (SH_DIV (1000000UL * 1000, ACTHZ, 8))
+/* TICK_NSEC is the time between ticks in nsec assuming SHIFTED_HZ */
+#define TICK_NSEC (SH_DIV(1000000UL * 1000, SHIFTED_HZ, 8))
/* TICK_USEC is the time between ticks in usec assuming fake USER_HZ */
#define TICK_USEC ((1000000UL + USER_HZ/2) / USER_HZ)
-/* TICK_USEC_TO_NSEC is the time between ticks in nsec assuming real ACTHZ and */
-/* a value TUSEC for TICK_USEC (can be set bij adjtimex) */
-#define TICK_USEC_TO_NSEC(TUSEC) (SH_DIV (TUSEC * USER_HZ * 1000, ACTHZ, 8))
+/*
+ * TICK_USEC_TO_NSEC is the time between ticks in nsec assuming SHIFTED_HZ and
+ * a value TUSEC for TICK_USEC (can be set bij adjtimex)
+ */
+#define TICK_USEC_TO_NSEC(TUSEC) (SH_DIV(TUSEC * USER_HZ * 1000, SHIFTED_HZ, 8))
/* some arch's have a small-data section that can be accessed register-relative
* but that can only take up to, say, 4-byte variables. jiffies being part of
OpenPOWER on IntegriCloud