Please see inline.
On 2/17/22 6:50 PM, Jerin Jacob wrote:
On Mon, Feb 7, 2022 at 1:00 PM Nithin Dabilpuram
<ndabilpu...@marvell.com> wrote:
From: Satha Rao <skotesh...@marvell.com>
New api to get floor values for a requested shaper rate, which can assure
Since it is internal API, no need to mention in the comment log
packets should never be transmitted at a rate higher than configured.
Keep the old api to get HW suggested values.
And introduce new parameter to select appropriate api.
api -> API
Signed-off-by: Satha Rao <skotesh...@marvell.com>
---
+static uint64_t
+nix_tm_shaper_rate_conv_floor(uint64_t value, uint64_t *exponent_p,
+ uint64_t *mantissa_p, uint64_t *div_exp_p)
+{
+ uint64_t div_exp, exponent, mantissa;
+
+ /* Boundary checks */
+ if (value < NIX_TM_MIN_SHAPER_RATE || value > NIX_TM_MAX_SHAPER_RATE)
+ return 0;
+
+ if (value <= NIX_TM_SHAPER_RATE(0, 0, 0)) {
+ /* Calculate rate div_exp and mantissa using
+ * the following formula:
+ *
+ * value = (2E6 * (256 + mantissa)
+ * / ((1 << div_exp) * 256))
+ */
+ div_exp = 0;
+ exponent = 0;
+ mantissa = NIX_TM_MAX_RATE_MANTISSA;
+
+ while (value <= (NIX_TM_SHAPER_RATE_CONST / (1 << div_exp)))
+ div_exp += 1;
+
+ while (value <= ((NIX_TM_SHAPER_RATE_CONST * (256 + mantissa)) /
+ ((1 << div_exp) * 256)))
+ mantissa -= 1;
Please move this as another static function.
This is not same as the non-floor function though it looks same. The
while loops terminate in <= in this function. Do you still need sub
functions for these ?
+ } else {
+ /* Calculate rate exponent and mantissa using
+ * the following formula:
+ *
+ * value = (2E6 * ((256 + mantissa) << exponent)) / 256
+ *
+ */
+ div_exp = 0;
+ exponent = NIX_TM_MAX_RATE_EXPONENT;
+ mantissa = NIX_TM_MAX_RATE_MANTISSA;
+
+ while (value <= (NIX_TM_SHAPER_RATE_CONST * (1 << exponent)))
+ exponent -= 1;
+
+ while (value <= ((NIX_TM_SHAPER_RATE_CONST *
+ ((256 + mantissa) << exponent)) /
+ 256))
+ mantissa -= 1;
Please move this as another static function.
Same comment as above.
+ }
+
+ if (div_exp > NIX_TM_MAX_RATE_DIV_EXP ||
+ exponent > NIX_TM_MAX_RATE_EXPONENT ||
+ mantissa > NIX_TM_MAX_RATE_MANTISSA)
+ return 0;
+
+ if (div_exp_p)
+ *div_exp_p = div_exp;
+ if (exponent_p)
+ *exponent_p = exponent;
+ if (mantissa_p)
+ *mantissa_p = mantissa;
+
+ /* Calculate real rate value */
+ return NIX_TM_SHAPER_RATE(exponent, mantissa, div_exp);
+}
+
+static uint64_t
+nix_tm_shaper_rate_conv_exact(uint64_t value, uint64_t *exponent_p,
+ uint64_t *mantissa_p, uint64_t *div_exp_p)
{
uint64_t div_exp, exponent, mantissa;
@@ -188,6 +251,23 @@ nix_tm_shaper_rate_conv(uint64_t value, uint64_t
*exponent_p,
return NIX_TM_SHAPER_RATE(exponent, mantissa, div_exp);
}
+/* With zero accuracy we will tune parameters as defined by HW,
+ * non zero accuracy will keep the parameters close to lower values
+ * and make sure long term shaper rate will not exceed requested rate.
long-term
requested -> the requested
