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Subject[PATCH 3/6] Add nsecs_to_cputime64 interface for asm-generic -v1
Date
Add nsecs_to_cputime64 interface. This is used in following patches that
updates cpu irq stat based on ns granularity info in IRQ_TIME_ACCOUNTING.

Tested-by: Shaun Ruffell <sruffell@digium.com>

Signed-off-by: Venkatesh Pallipadi <venki@google.com>
---
include/asm-generic/cputime.h | 3 +++
include/linux/jiffies.h | 1 +
kernel/time.c | 23 +++++++++++++++++++++--
3 files changed, 25 insertions(+), 2 deletions(-)
diff --git a/include/asm-generic/cputime.h b/include/asm-generic/cputime.h
index ca0f239..c0f0da0 100644
--- a/include/asm-generic/cputime.h
+++ b/include/asm-generic/cputime.h
@@ -30,6 +30,9 @@ typedef u64 cputime64_t;
#define cputime64_to_jiffies64(__ct) (__ct)
#define jiffies64_to_cputime64(__jif) (__jif)
#define cputime_to_cputime64(__ct) ((u64) __ct)
+#define cputime64_gt(__a, __b) ((__a) > (__b))
+
+#define nsecs_to_cputime64(__ct) nsecs_to_jiffies64(__ct)


/*
diff --git a/include/linux/jiffies.h b/include/linux/jiffies.h
index 6811f4b..922aa31 100644
--- a/include/linux/jiffies.h
+++ b/include/linux/jiffies.h
@@ -307,6 +307,7 @@ extern clock_t jiffies_to_clock_t(long x);
extern unsigned long clock_t_to_jiffies(unsigned long x);
extern u64 jiffies_64_to_clock_t(u64 x);
extern u64 nsec_to_clock_t(u64 x);
+extern u64 nsecs_to_jiffies64(u64 n);
extern unsigned long nsecs_to_jiffies(u64 n);

#define TIMESTAMP_SIZE 30
diff --git a/kernel/time.c b/kernel/time.c
index ba9b338..fde4691 100644
--- a/kernel/time.c
+++ b/kernel/time.c
@@ -645,7 +645,7 @@ u64 nsec_to_clock_t(u64 x)
}

/**
- * nsecs_to_jiffies - Convert nsecs in u64 to jiffies
+ * nsecs_to_jiffies64 - Convert nsecs in u64 to jiffies64
*
* @n: nsecs in u64
*
@@ -657,7 +657,7 @@ u64 nsec_to_clock_t(u64 x)
* NSEC_PER_SEC = 10^9 = (5^9 * 2^9) = (1953125 * 512)
* ULLONG_MAX ns = 18446744073.709551615 secs = about 584 years
*/
-unsigned long nsecs_to_jiffies(u64 n)
+u64 nsecs_to_jiffies64(u64 n)
{
#if (NSEC_PER_SEC % HZ) == 0
/* Common case, HZ = 100, 128, 200, 250, 256, 500, 512, 1000 etc. */
@@ -674,6 +674,25 @@ unsigned long nsecs_to_jiffies(u64 n)
#endif
}

+
+/**
+ * nsecs_to_jiffies - Convert nsecs in u64 to jiffies
+ *
+ * @n: nsecs in u64
+ *
+ * Unlike {m,u}secs_to_jiffies, type of input is not unsigned int but u64.
+ * And this doesn't return MAX_JIFFY_OFFSET since this function is designed
+ * for scheduler, not for use in device drivers to calculate timeout value.
+ *
+ * note:
+ * NSEC_PER_SEC = 10^9 = (5^9 * 2^9) = (1953125 * 512)
+ * ULLONG_MAX ns = 18446744073.709551615 secs = about 584 years
+ */
+unsigned long nsecs_to_jiffies(u64 n)
+{
+ return (unsigned long)nsecs_to_jiffies64(n);
+}
+
#if (BITS_PER_LONG < 64)
u64 get_jiffies_64(void)
{
--
1.7.1


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