net: ipa: rework ipa_aggr_granularity_val()

The timer used for aggregation makes use of an internal 32 KHz clock.
The granularity of the timer is programmed by a field whose value is
computed by ipa_aggr_granularity_val().  Redefine the way that value
is computed by using a new TIMER_FREQUENCY constant representing the
underlying clock frequency.

Add two BUILD_BUG_ON() calls to ensure the value used is valid.

Signed-off-by: Alex Elder <elder@linaro.org>
Signed-off-by: David S. Miller <davem@davemloft.net>
This commit is contained in:
Alex Elder 2020-06-29 16:55:21 -05:00 committed by David S. Miller
parent 8c96439724
commit 317a5740b7
2 changed files with 13 additions and 9 deletions

View File

@ -674,6 +674,11 @@ static void ipa_validate_build(void)
/* This is used as a divisor */
BUILD_BUG_ON(!IPA_AGGR_GRANULARITY);
/* Aggregation granularity value can't be 0, and must fit */
BUILD_BUG_ON(!ipa_aggr_granularity_val(IPA_AGGR_GRANULARITY));
BUILD_BUG_ON(ipa_aggr_granularity_val(IPA_AGGR_GRANULARITY) >
field_max(AGGR_GRANULARITY));
#endif /* IPA_VALIDATE */
}

View File

@ -190,24 +190,23 @@ static inline u32 ipa_reg_bcr_val(enum ipa_version version)
return 0x00000000;
}
#define IPA_REG_LOCAL_PKT_PROC_CNTXT_BASE_OFFSET 0x000001e8
#define IPA_REG_AGGR_FORCE_CLOSE_OFFSET 0x000001ec
/* ipa->available defines the valid bits in the AGGR_FORCE_CLOSE register */
/* The internal inactivity timer clock is used for the aggregation timer */
#define TIMER_FREQUENCY 32000 /* 32 KHz inactivity timer clock */
#define IPA_REG_COUNTER_CFG_OFFSET 0x000001f0
#define AGGR_GRANULARITY GENMASK(8, 4)
/* Compute the value to use in the AGGR_GRANULARITY field representing
* the given number of microseconds (up to 1 millisecond).
* x = (32 * usec) / 1000 - 1
/* Compute the value to use in the AGGR_GRANULARITY field representing the
* given number of microseconds. The value is one less than the number of
* timer ticks in the requested period. Zero not a valid granularity value.
*/
static inline u32 ipa_aggr_granularity_val(u32 microseconds)
static inline u32 ipa_aggr_granularity_val(u32 usec)
{
/* assert(microseconds >= 16); (?) */
/* assert(microseconds <= 1015); */
return DIV_ROUND_CLOSEST(32 * microseconds, 1000) - 1;
return DIV_ROUND_CLOSEST(usec * TIMER_FREQUENCY, USEC_PER_SEC) - 1;
}
#define IPA_REG_TX_CFG_OFFSET 0x000001fc