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: Alex Elder <elder@linaro.org>
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
This commit is contained in:
Alex Elder 2022-09-22 17:20:54 -05:00 committed by Jakub Kicinski
parent a50d37b756
commit 8be440e17b

View File

@ -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);
}