[S390] cputime: add sparse checking and cleanup

Make cputime_t and cputime64_t nocast to enable sparse checking to
detect incorrect use of cputime. Drop the cputime macros for simple
scalar operations. The conversion macros are still needed.

Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>

1 files changed, 63 insertions, 77 deletions

diff --git a/arch/s390/include/asm/cputime.h b/arch/s390/include/asm/cputime.h
index 081434878296..0887a0463e33 100644
--- a/arch/s390/include/asm/cputime.h
+++ b/arch/s390/include/asm/cputime.h
@@ -16,114 +16,98 @@
 
 /* We want to use full resolution of the CPU timer: 2**-12 micro-seconds. */
 
-typedef unsigned long long cputime_t;
-typedef unsigned long long cputime64_t;
+typedef unsigned long long __nocast cputime_t;
+typedef unsigned long long __nocast cputime64_t;
 
-#ifndef __s390x__
-
-static inline unsigned int
-__div(unsigned long long n, unsigned int base)
+static inline unsigned long __div(unsigned long long n, unsigned long base)
 {
+#ifndef __s390x__
         register_pair rp;
 
         rp.pair = n >> 1;
         asm ("dr %0,%1" : "+d" (rp) : "d" (base >> 1));
         return rp.subreg.odd;
+#else /* __s390x__ */
+        return n / base;
+#endif /* __s390x__ */
 }
 
-#else /* __s390x__ */
+#define cputime_one_jiffy               jiffies_to_cputime(1)
 
-static inline unsigned int
-__div(unsigned long long n, unsigned int base)
+/*
+ * Convert cputime to jiffies and back.
+ */
+static inline unsigned long cputime_to_jiffies(const cputime_t cputime)
 {
-        return n / base;
+        return __div((__force unsigned long long) cputime, 4096000000ULL / HZ);
 }
 
-#endif /* __s390x__ */
+static inline cputime_t jiffies_to_cputime(const unsigned int jif)
+{
+        return (__force cputime_t)(jif * (4096000000ULL / HZ));
+}
 
-#define cputime_zero                    (0ULL)
-#define cputime_one_jiffy               jiffies_to_cputime(1)
-#define cputime_max                     ((~0UL >> 1) - 1)
-#define cputime_add(__a, __b)           ((__a) +  (__b))
-#define cputime_sub(__a, __b)           ((__a) -  (__b))
-#define cputime_div(__a, __n) ({                \
-        unsigned long long __div = (__a);       \
-        do_div(__div,__n);                      \
-        __div;                                  \
-})
-#define cputime_halve(__a)              ((__a) >> 1)
-#define cputime_eq(__a, __b)            ((__a) == (__b))
-#define cputime_gt(__a, __b)            ((__a) >  (__b))
-#define cputime_ge(__a, __b)            ((__a) >= (__b))
-#define cputime_lt(__a, __b)            ((__a) <  (__b))
-#define cputime_le(__a, __b)            ((__a) <= (__b))
-#define cputime_to_jiffies(__ct)        (__div((__ct), 4096000000ULL / HZ))
-#define cputime_to_scaled(__ct)         (__ct)
-#define jiffies_to_cputime(__hz)        ((cputime_t)(__hz) * (4096000000ULL / HZ))
-
-#define cputime64_zero                  (0ULL)
-#define cputime64_add(__a, __b)         ((__a) + (__b))
-#define cputime_to_cputime64(__ct)      (__ct)
-
-static inline u64
-cputime64_to_jiffies64(cputime64_t cputime)
-{
-        do_div(cputime, 4096000000ULL / HZ);
-        return cputime;
+static inline u64 cputime64_to_jiffies64(cputime64_t cputime)
+{
+        unsigned long long jif = (__force unsigned long long) cputime;
+        do_div(jif, 4096000000ULL / HZ);
+        return jif;
+}
+
+static inline cputime64_t jiffies64_to_cputime64(const u64 jif)
+{
+        return (__force cputime64_t)(jif * (4096000000ULL / HZ));
 }
 
 /*
  * Convert cputime to microseconds and back.
  */
-static inline unsigned int
-cputime_to_usecs(const cputime_t cputime)
+static inline unsigned int cputime_to_usecs(const cputime_t cputime)
 {
-        return cputime_div(cputime, 4096);
+        return (__force unsigned long long) cputime >> 12;
 }
 
-static inline cputime_t
-usecs_to_cputime(const unsigned int m)
+static inline cputime_t usecs_to_cputime(const unsigned int m)
 {
-        return (cputime_t) m * 4096;
+        return (__force cputime_t)(m * 4096ULL);
 }
 
 /*
  * Convert cputime to milliseconds and back.
  */
-static inline unsigned int
-cputime_to_secs(const cputime_t cputime)
+static inline unsigned int cputime_to_secs(const cputime_t cputime)
 {
-        return __div(cputime, 2048000000) >> 1;
+        return __div((__force unsigned long long) cputime, 2048000000) >> 1;
 }
 
-static inline cputime_t
-secs_to_cputime(const unsigned int s)
+static inline cputime_t secs_to_cputime(const unsigned int s)
 {
-        return (cputime_t) s * 4096000000ULL;
+        return (__force cputime_t)(s * 4096000000ULL);
 }
 
 /*
  * Convert cputime to timespec and back.
  */
-static inline cputime_t
-timespec_to_cputime(const struct timespec *value)
+static inline cputime_t timespec_to_cputime(const struct timespec *value)
 {
-        return value->tv_nsec * 4096 / 1000 + (u64) value->tv_sec * 4096000000ULL;
+        unsigned long long ret = value->tv_sec * 4096000000ULL;
+        return (__force cputime_t)(ret + value->tv_nsec * 4096 / 1000);
 }
 
-static inline void
-cputime_to_timespec(const cputime_t cputime, struct timespec *value)
+static inline void cputime_to_timespec(const cputime_t cputime,
+                                       struct timespec *value)
 {
+        unsigned long long __cputime = (__force unsigned long long) cputime;
 #ifndef __s390x__
         register_pair rp;
 
-        rp.pair = cputime >> 1;
+        rp.pair = __cputime >> 1;
         asm ("dr %0,%1" : "+d" (rp) : "d" (2048000000UL));
         value->tv_nsec = rp.subreg.even * 1000 / 4096;
         value->tv_sec = rp.subreg.odd;
 #else
-        value->tv_nsec = (cputime % 4096000000ULL) * 1000 / 4096;
-        value->tv_sec = cputime / 4096000000ULL;
+        value->tv_nsec = (__cputime % 4096000000ULL) * 1000 / 4096;
+        value->tv_sec = __cputime / 4096000000ULL;
 #endif
 }
 
@@ -132,50 +116,52 @@ cputime_to_timespec(const cputime_t cputime, struct timespec *value)
  * Since cputime and timeval have the same resolution (microseconds)
  * this is easy.
  */
-static inline cputime_t
-timeval_to_cputime(const struct timeval *value)
+static inline cputime_t timeval_to_cputime(const struct timeval *value)
 {
-        return value->tv_usec * 4096 + (u64) value->tv_sec * 4096000000ULL;
+        unsigned long long ret = value->tv_sec * 4096000000ULL;
+        return (__force cputime_t)(ret + value->tv_usec * 4096ULL);
 }
 
-static inline void
-cputime_to_timeval(const cputime_t cputime, struct timeval *value)
+static inline void cputime_to_timeval(const cputime_t cputime,
+                                      struct timeval *value)
 {
+        unsigned long long __cputime = (__force unsigned long long) cputime;
 #ifndef __s390x__
         register_pair rp;
 
-        rp.pair = cputime >> 1;
+        rp.pair = __cputime >> 1;
         asm ("dr %0,%1" : "+d" (rp) : "d" (2048000000UL));
         value->tv_usec = rp.subreg.even / 4096;
         value->tv_sec = rp.subreg.odd;
 #else
-        value->tv_usec = (cputime % 4096000000ULL) / 4096;
-        value->tv_sec = cputime / 4096000000ULL;
+        value->tv_usec = (__cputime % 4096000000ULL) / 4096;
+        value->tv_sec = __cputime / 4096000000ULL;
 #endif
 }
 
 /*
  * Convert cputime to clock and back.
  */
-static inline clock_t
-cputime_to_clock_t(cputime_t cputime)
+static inline clock_t cputime_to_clock_t(cputime_t cputime)
 {
-        return cputime_div(cputime, 4096000000ULL / USER_HZ);
+        unsigned long long clock = (__force unsigned long long) cputime;
+        do_div(clock, 4096000000ULL / USER_HZ);
+        return clock;
 }
 
-static inline cputime_t
-clock_t_to_cputime(unsigned long x)
+static inline cputime_t clock_t_to_cputime(unsigned long x)
 {
-        return (cputime_t) x * (4096000000ULL / USER_HZ);
+        return (__force cputime_t)(x * (4096000000ULL / USER_HZ));
 }
 
 /*
  * Convert cputime64 to clock.
  */
-static inline clock_t
-cputime64_to_clock_t(cputime64_t cputime)
+static inline clock_t cputime64_to_clock_t(cputime64_t cputime)
 {
-       return cputime_div(cputime, 4096000000ULL / USER_HZ);
+        unsigned long long clock = (__force unsigned long long) cputime;
+        do_div(clock, 4096000000ULL / USER_HZ);
+        return clock;
 }
 
 struct s390_idle_data {