#ifndef _LINUX_JIFFIES_H #define _LINUX_JIFFIES_H #include #include /* for HZ */ /* * The 64-bit value is not volatile - you MUST NOT read it * without holding read_lock_irq(&xtime_lock) */ extern u64 jiffies_64; extern unsigned long volatile jiffies; /* * These inlines deal with timer wrapping correctly. You are * strongly encouraged to use them * 1. Because people otherwise forget * 2. Because if the timer wrap changes in future you wont have to * alter your driver code. * * time_after(a,b) returns true if the time a is after time b. * * Do this with "<0" and ">=0" to only test the sign of the result. A * good compiler would generate better code (and a really good compiler * wouldn't care). Gcc is currently neither. */ #define time_after(a,b) ((long)(b) - (long)(a) < 0) #define time_before(a,b) time_after(b,a) #define time_after_eq(a,b) ((long)(a) - (long)(b) >= 0) #define time_before_eq(a,b) time_after_eq(b,a) #endif