diff mbox series

[net-next,5/7] i40e: convert .adjfreq to .adjfine

Message ID 20220728181836.3387862-6-anthony.l.nguyen@intel.com (mailing list archive)
State Accepted
Commit ccd3bf98592117f59be2daa0f2ca00f352d7abbc
Delegated to: Netdev Maintainers
Headers show
Series 1GbE Intel Wired LAN Driver Updates 2022-07-28 | expand

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netdev/patch_count success Link
netdev/header_inline success No static functions without inline keyword in header files
netdev/build_32bit success Errors and warnings before: 0 this patch: 0
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netdev/module_param success Was 0 now: 0
netdev/verify_signedoff success Signed-off-by tag matches author and committer
netdev/check_selftest success No net selftest shell script
netdev/verify_fixes success No Fixes tag
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netdev/checkpatch success total: 0 errors, 0 warnings, 0 checks, 48 lines checked
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netdev/source_inline success Was 0 now: 0

Commit Message

Tony Nguyen July 28, 2022, 6:18 p.m. UTC 
From: Jacob Keller <jacob.e.keller@intel.com>

The i40e driver currently implements the .adjfreq handler for frequency
adjustments. This takes the adjustment parameter in parts per billion. The
PTP core supports .adjfine which provides an adjustment in scaled parts per
million. This has a higher resolution and can result in more precise
adjustments for small corrections.

Convert the existing .adjfreq implementation to the newer .adjfine
implementation. This is trivial since it just requires changing the divisor
from 1000000000ULL to (1000000ULL << 16) in the mul_u64_u64_div_u64 call.

This improves the precision of the adjustments and gets us one driver
closer to removing the old .adjfreq support from the kernel.

Signed-off-by: Jacob Keller <jacob.e.keller@intel.com>
Tested-by: Gurucharan <gurucharanx.g@intel.com> (A Contingent worker at Intel)
Signed-off-by: Tony Nguyen <anthony.l.nguyen@intel.com>
---
 drivers/net/ethernet/intel/i40e/i40e_ptp.c | 22 ++++++++++++----------
 1 file changed, 12 insertions(+), 10 deletions(-)
diff mbox series

Patch

diff --git a/drivers/net/ethernet/intel/i40e/i40e_ptp.c b/drivers/net/ethernet/intel/i40e/i40e_ptp.c
index 15de918abc41..2d3533f38d7b 100644
--- a/drivers/net/ethernet/intel/i40e/i40e_ptp.c
+++ b/drivers/net/ethernet/intel/i40e/i40e_ptp.c
@@ -334,29 +334,31 @@  static void i40e_ptp_convert_to_hwtstamp(struct skb_shared_hwtstamps *hwtstamps,
 }
 
 /**
- * i40e_ptp_adjfreq - Adjust the PHC frequency
+ * i40e_ptp_adjfine - Adjust the PHC frequency
  * @ptp: The PTP clock structure
- * @ppb: Parts per billion adjustment from the base
+ * @scaled_ppm: Scaled parts per million adjustment from base
  *
- * Adjust the frequency of the PHC by the indicated parts per billion from the
- * base frequency.
+ * Adjust the frequency of the PHC by the indicated delta from the base
+ * frequency.
+ *
+ * Scaled parts per million is ppm with a 16 bit binary fractional field.
  **/
-static int i40e_ptp_adjfreq(struct ptp_clock_info *ptp, s32 ppb)
+static int i40e_ptp_adjfine(struct ptp_clock_info *ptp, long scaled_ppm)
 {
 	struct i40e_pf *pf = container_of(ptp, struct i40e_pf, ptp_caps);
 	struct i40e_hw *hw = &pf->hw;
 	u64 adj, freq, diff;
 	int neg_adj = 0;
 
-	if (ppb < 0) {
+	if (scaled_ppm < 0) {
 		neg_adj = 1;
-		ppb = -ppb;
+		scaled_ppm = -scaled_ppm;
 	}
 
 	smp_mb(); /* Force any pending update before accessing. */
 	freq = I40E_PTP_40GB_INCVAL * READ_ONCE(pf->ptp_adj_mult);
-	diff = mul_u64_u64_div_u64(freq, (u64)ppb,
-				   1000000000ULL);
+	diff = mul_u64_u64_div_u64(freq, (u64)scaled_ppm,
+				   1000000ULL << 16);
 
 	if (neg_adj)
 		adj = I40E_PTP_40GB_INCVAL - diff;
@@ -1392,7 +1394,7 @@  static long i40e_ptp_create_clock(struct i40e_pf *pf)
 		sizeof(pf->ptp_caps.name) - 1);
 	pf->ptp_caps.owner = THIS_MODULE;
 	pf->ptp_caps.max_adj = 999999999;
-	pf->ptp_caps.adjfreq = i40e_ptp_adjfreq;
+	pf->ptp_caps.adjfine = i40e_ptp_adjfine;
 	pf->ptp_caps.adjtime = i40e_ptp_adjtime;
 	pf->ptp_caps.gettimex64 = i40e_ptp_gettimex;
 	pf->ptp_caps.settime64 = i40e_ptp_settime;