Commit 317a5740 authored by Alex Elder's avatar Alex Elder Committed by David S. Miller
Browse files

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: default avatarAlex Elder <elder@linaro.org>
Signed-off-by: default avatarDavid S. Miller <davem@davemloft.net>
parent 8c964397

drivers/net/ipa/ipa_main.c

+5 −0
Original line number Diff line number Diff line
@@ -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 */

}

drivers/net/ipa/ipa_reg.h

+8 −9
Original line number Diff line number Diff line
@@ -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

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