Commit 8be440e1 authored by Alex Elder's avatar Alex Elder Committed by Jakub Kicinski
Browse files

net: ipa: introduce ipa_qtime_val() 



Create a new function ipa_qtime_val() which returns a value that
indicates what should be encoded for a register with a time field
expressed using Qtime.  Use it to factor out common code in
aggr_time_limit_encoded() and hol_block_timer_qtime_val().

Rename aggr_time_limit_encoded() and hol_block_timer_qtime_val() so
their names are both verbs ending in "encode".  Rename the "limit"
argument to the former to be "milliseconds" for consistency.

Signed-off-by: default avatarAlex Elder <elder@linaro.org>
Signed-off-by: default avatarJakub Kicinski <kuba@kernel.org>
parent a50d37b7

drivers/net/ipa/ipa_endpoint.c

+44 −36
Original line number Diff line number Diff line
@@ -725,17 +725,42 @@ static u32 aggr_byte_limit_encoded(enum ipa_version version, u32 limit) 
	return u32_encode_bits(limit, aggr_byte_limit_fmask(false));

}



/* For IPA v4.5+, times are expressed using Qtime.  The AP uses one of two

 * pulse generators (0 and 1) to measure elapsed time.  In ipa_qtime_config()

 * they're configured to have granularity 100 usec and 1 msec, respectively.

 *

 * The return value is the positive or negative Qtime value to use to

 * express the (microsecond) time provided.  A positive return value

 * means pulse generator 0 can be used; otherwise use pulse generator 1.

 */

static int ipa_qtime_val(u32 microseconds, u32 max)

{

	u32 val;



	/* Use 100 microsecond granularity if possible */

	val = DIV_ROUND_CLOSEST(microseconds, 100);

	if (val <= max)

		return (int)val;



	/* Have to use pulse generator 1 (millisecond granularity) */

	val = DIV_ROUND_CLOSEST(microseconds, 1000);

	WARN_ON(val > max);



	return (int)-val;

}



/* Encode the aggregation timer limit (microseconds) based on IPA version */

static u32 aggr_time_limit_encoded(enum ipa_version version, u32 limit)

static u32 aggr_time_limit_encode(enum ipa_version version, u32 microseconds)

{

	u32 gran_sel;

	u32 fmask;

	u32 val;

	int ret;



	if (version < IPA_VERSION_4_5) {

		/* We set aggregation granularity in ipa_hardware_config() */

		fmask = aggr_time_limit_fmask(true);

		val = DIV_ROUND_CLOSEST(limit, IPA_AGGR_GRANULARITY);

		val = DIV_ROUND_CLOSEST(microseconds, IPA_AGGR_GRANULARITY);

		WARN(val > field_max(fmask),

		     "aggr_time_limit too large (%u > %u usec)\n",

		     val, field_max(fmask) * IPA_AGGR_GRANULARITY);
@@ -743,23 +768,14 @@ static u32 aggr_time_limit_encoded(enum ipa_version version, u32 limit) 
		return u32_encode_bits(val, fmask);

	}



	/* IPA v4.5 expresses the time limit using Qtime.  The AP has

	 * pulse generators 0 and 1 available, which were configured

	 * in ipa_qtime_config() to have granularity 100 usec and

	 * 1 msec, respectively.  Use pulse generator 0 if possible,

	 * otherwise fall back to pulse generator 1.

	 */

	/* Compute the Qtime limit value to use */

	fmask = aggr_time_limit_fmask(false);

	val = DIV_ROUND_CLOSEST(limit, 100);

	if (val > field_max(fmask)) {

		/* Have to use pulse generator 1 (millisecond granularity) */

	ret = ipa_qtime_val(microseconds, field_max(fmask));

	if (ret < 0) {

		val = -ret;

		gran_sel = AGGR_GRAN_SEL_FMASK;

		val = DIV_ROUND_CLOSEST(limit, 1000);

		WARN(val > field_max(fmask),

		     "aggr_time_limit too large (%u > %u usec)\n",

		     limit, field_max(fmask) * 1000);

	} else {

		/* We can use pulse generator 0 (100 usec granularity) */

		val = ret;

		gran_sel = 0;

	}
@@ -799,7 +815,7 @@ static void ipa_endpoint_init_aggr(struct ipa_endpoint *endpoint) 
			val |= aggr_byte_limit_encoded(version, limit);



			limit = rx_config->aggr_time_limit;

			val |= aggr_time_limit_encoded(version, limit);

			val |= aggr_time_limit_encode(version, limit);



			/* AGGR_PKT_LIMIT is 0 (unlimited) */
@@ -825,24 +841,18 @@ static void ipa_endpoint_init_aggr(struct ipa_endpoint *endpoint) 
 * represents the given number of microseconds.  The result

 * includes both the timer value and the selected timer granularity.

 */

static u32 hol_block_timer_qtime_val(struct ipa *ipa, u32 microseconds)

static u32 hol_block_timer_qtime_encode(struct ipa *ipa, u32 microseconds)

{

	u32 gran_sel;

	u32 val;

	int ret;



	/* IPA v4.5 expresses time limits using Qtime.  The AP has

	 * pulse generators 0 and 1 available, which were configured

	 * in ipa_qtime_config() to have granularity 100 usec and

	 * 1 msec, respectively.  Use pulse generator 0 if possible,

	 * otherwise fall back to pulse generator 1.

	 */

	val = DIV_ROUND_CLOSEST(microseconds, 100);

	if (val > field_max(TIME_LIMIT_FMASK)) {

		/* Have to use pulse generator 1 (millisecond granularity) */

	ret = ipa_qtime_val(microseconds, field_max(TIME_LIMIT_FMASK));

	if (ret < 0) {

		val = -ret;

		gran_sel = GRAN_SEL_FMASK;

		val = DIV_ROUND_CLOSEST(microseconds, 1000);

	} else {

		/* We can use pulse generator 0 (100 usec granularity) */

		val = ret;

		gran_sel = 0;

	}
@@ -854,12 +864,10 @@ static u32 hol_block_timer_qtime_val(struct ipa *ipa, u32 microseconds) 
 * derived from the 19.2 MHz SoC XO clock.  For older IPA versions

 * each tick represents 128 cycles of the IPA core clock.

 *

 * Return the encoded value that should be written to that register

 * that represents the timeout period provided.  For IPA v4.2 this

 * encodes a base and scale value, while for earlier versions the

 * value is a simple tick count.

 * Return the encoded value representing the timeout period provided

 * that should be written to the ENDP_INIT_HOL_BLOCK_TIMER register.

 */

static u32 hol_block_timer_val(struct ipa *ipa, u32 microseconds)

static u32 hol_block_timer_encode(struct ipa *ipa, u32 microseconds)

{

	u32 width;

	u32 scale;
@@ -872,7 +880,7 @@ static u32 hol_block_timer_val(struct ipa *ipa, u32 microseconds) 
		return 0;	/* Nothing to compute if timer period is 0 */



	if (ipa->version >= IPA_VERSION_4_5)

		return hol_block_timer_qtime_val(ipa, microseconds);

		return hol_block_timer_qtime_encode(ipa, microseconds);



	/* Use 64 bit arithmetic to avoid overflow... */

	rate = ipa_core_clock_rate(ipa);
@@ -920,7 +928,7 @@ static void ipa_endpoint_init_hol_block_timer(struct ipa_endpoint *endpoint, 


	/* This should only be changed when HOL_BLOCK_EN is disabled */

	offset = IPA_REG_ENDP_INIT_HOL_BLOCK_TIMER_N_OFFSET(endpoint_id);

	val = hol_block_timer_val(ipa, microseconds);

	val = hol_block_timer_encode(ipa, microseconds);

	iowrite32(val, ipa->reg_virt + offset);

}