[NET_SCHED]: Use ktime as clocksource

Get rid of the manual clock source selection mess and use ktime. Also
use a scalar representation, which allows to clean up pkt_sched.h a bit
more and results in less ktime_to_ns() calls in most cases.

The PSCHED_US2JIFFIE/PSCHED_JIFFIE2US macros are implemented quite
inefficient by this patch, following patches will convert all qdiscs
to hrtimers and get rid of them entirely.

Signed-off-by: Patrick McHardy <kaber@trash.net>
Signed-off-by: David S. Miller <davem@davemloft.net>

1 files changed, 3 insertions, 28 deletions

diff --git a/net/sched/sch_hfsc.c b/net/sched/sch_hfsc.c
index 407c6fb1ba1..f85cfba647f 100644
--- a/net/sched/sch_hfsc.c
+++ b/net/sched/sch_hfsc.c
@@ -195,20 +195,6 @@ struct hfsc_sched
         struct timer_list wd_timer;             /* watchdog timer */
 };
 
-/*
- * macros
- */
-#ifdef CONFIG_NET_SCH_CLK_GETTIMEOFDAY
-#include <linux/time.h>
-#undef PSCHED_GET_TIME
-#define PSCHED_GET_TIME(stamp)                                          \
-do {                                                                    \
-        struct timeval tv;                                              \
-        do_gettimeofday(&tv);                                           \
-        (stamp) = 1ULL * USEC_PER_SEC * tv.tv_sec + tv.tv_usec;         \
-} while (0)
-#endif
-
 #define HT_INFINITY     0xffffffffffffffffULL   /* infinite time value */
 
 
@@ -394,28 +380,17 @@ cftree_update(struct hfsc_class *cl)
  *      ism: (psched_us/byte) << ISM_SHIFT
  *      dx: psched_us
  *
- * Clock source resolution (CONFIG_NET_SCH_CLK_*)
- *  JIFFIES: for 48<=HZ<=1534 resolution is between 0.63us and 1.27us.
- *  CPU: resolution is between 0.5us and 1us.
- *  GETTIMEOFDAY: resolution is exactly 1us.
+ * The clock source resolution with ktime is 1.024us.
  *
  * sm and ism are scaled in order to keep effective digits.
  * SM_SHIFT and ISM_SHIFT are selected to keep at least 4 effective
  * digits in decimal using the following table.
  *
- * Note: We can afford the additional accuracy (altq hfsc keeps at most
- * 3 effective digits) thanks to the fact that linux clock is bounded
- * much more tightly.
- *
  *  bits/sec      100Kbps     1Mbps     10Mbps     100Mbps    1Gbps
  *  ------------+-------------------------------------------------------
- *  bytes/0.5us   6.25e-3    62.5e-3    625e-3     6250e-e    62500e-3
- *  bytes/us      12.5e-3    125e-3     1250e-3    12500e-3   125000e-3
- *  bytes/1.27us  15.875e-3  158.75e-3  1587.5e-3  15875e-3   158750e-3
+ *  bytes/1.024us 12.8e-3    128e-3     1280e-3    12800e-3   128000e-3
  *
- *  0.5us/byte    160        16         1.6        0.16       0.016
- *  us/byte       80         8          0.8        0.08       0.008
- *  1.27us/byte   63         6.3        0.63       0.063      0.0063
+ *  1.024us/byte  78.125     7.8125     0.78125    0.078125   0.0078125
  */
 #define SM_SHIFT        20
 #define ISM_SHIFT       18