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Message-Id: <1667780192-3700-4-git-send-email-michael.chan@broadcom.com>
Date: Sun, 6 Nov 2022 19:16:32 -0500
From: Michael Chan <michael.chan@...adcom.com>
To: davem@...emloft.net
Cc: netdev@...r.kernel.org, kuba@...nel.org, edumazet@...gle.com,
pabeni@...hat.com, gospo@...adcom.com, pavan.chebbi@...adcom.com
Subject: [PATCH net-next 3/3] bnxt_en: Add a non-real time mode to access NIC clock
From: Pavan Chebbi <pavan.chebbi@...adcom.com>
When using a PHC that is shared between multiple hosts,
in order to achieve consistent timestamps across all hosts,
we need to isolate the PHC from any host making frequency
adjustments.
This patch adds a non-real time mode for this purpose.
The implementation is based on a free running NIC hardware timer
which is used as the timestamper time-base. Each host implements
individual adjustments to a local timecounter based on the NIC free
running timer.
Cc: Richard Cochran <richardcochran@...il.com>
Signed-off-by: Pavan Chebbi <pavan.chebbi@...adcom.com>
Reviewed-by: Andy Gospodarek <andrew.gospodarek@...adcom.com>
Signed-off-by: Michael Chan <michael.chan@...adcom.com>
---
drivers/net/ethernet/broadcom/bnxt/bnxt.c | 5 ++-
drivers/net/ethernet/broadcom/bnxt/bnxt_ptp.c | 45 ++++++++++++++-----
drivers/net/ethernet/broadcom/bnxt/bnxt_ptp.h | 7 ++-
3 files changed, 42 insertions(+), 15 deletions(-)
diff --git a/drivers/net/ethernet/broadcom/bnxt/bnxt.c b/drivers/net/ethernet/broadcom/bnxt/bnxt.c
index d18e55b16375..d9ad325f7840 100644
--- a/drivers/net/ethernet/broadcom/bnxt/bnxt.c
+++ b/drivers/net/ethernet/broadcom/bnxt/bnxt.c
@@ -6985,8 +6985,11 @@ static int bnxt_hwrm_func_qcfg(struct bnxt *bp)
if (flags & FUNC_QCFG_RESP_FLAGS_FW_DCBX_AGENT_ENABLED)
bp->fw_cap |= BNXT_FW_CAP_DCBX_AGENT;
}
- if (BNXT_PF(bp) && (flags & FUNC_QCFG_RESP_FLAGS_MULTI_HOST))
+ if (BNXT_PF(bp) && (flags & FUNC_QCFG_RESP_FLAGS_MULTI_HOST)) {
bp->flags |= BNXT_FLAG_MULTI_HOST;
+ if (bp->fw_cap & BNXT_FW_CAP_PTP_RTC)
+ bp->fw_cap &= ~BNXT_FW_CAP_PTP_RTC;
+ }
if (flags & FUNC_QCFG_RESP_FLAGS_RING_MONITOR_ENABLED)
bp->fw_cap |= BNXT_FW_CAP_RING_MONITOR;
diff --git a/drivers/net/ethernet/broadcom/bnxt/bnxt_ptp.c b/drivers/net/ethernet/broadcom/bnxt/bnxt_ptp.c
index 2132ce63193c..460cb20599f6 100644
--- a/drivers/net/ethernet/broadcom/bnxt/bnxt_ptp.c
+++ b/drivers/net/ethernet/broadcom/bnxt/bnxt_ptp.c
@@ -14,6 +14,7 @@
#include <linux/net_tstamp.h>
#include <linux/timekeeping.h>
#include <linux/ptp_classify.h>
+#include <linux/clocksource.h>
#include "bnxt_hsi.h"
#include "bnxt.h"
#include "bnxt_hwrm.h"
@@ -210,18 +211,37 @@ static int bnxt_ptp_adjfreq(struct ptp_clock_info *ptp_info, s32 ppb)
ptp_info);
struct hwrm_port_mac_cfg_input *req;
struct bnxt *bp = ptp->bp;
- int rc;
+ int rc = 0;
- rc = hwrm_req_init(bp, req, HWRM_PORT_MAC_CFG);
- if (rc)
- return rc;
+ if (!(ptp->bp->fw_cap & BNXT_FW_CAP_PTP_RTC)) {
+ int neg_adj = 0;
+ u32 diff;
+ u64 adj;
- req->ptp_freq_adj_ppb = cpu_to_le32(ppb);
- req->enables = cpu_to_le32(PORT_MAC_CFG_REQ_ENABLES_PTP_FREQ_ADJ_PPB);
- rc = hwrm_req_send(ptp->bp, req);
- if (rc)
- netdev_err(ptp->bp->dev,
- "ptp adjfreq failed. rc = %d\n", rc);
+ if (ppb < 0) {
+ neg_adj = 1;
+ ppb = -ppb;
+ }
+ adj = ptp->cmult;
+ adj *= ppb;
+ diff = div_u64(adj, 1000000000ULL);
+
+ spin_lock_bh(&ptp->ptp_lock);
+ timecounter_read(&ptp->tc);
+ ptp->cc.mult = neg_adj ? ptp->cmult - diff : ptp->cmult + diff;
+ spin_unlock_bh(&ptp->ptp_lock);
+ } else {
+ rc = hwrm_req_init(bp, req, HWRM_PORT_MAC_CFG);
+ if (rc)
+ return rc;
+
+ req->ptp_freq_adj_ppb = cpu_to_le32(ppb);
+ req->enables = cpu_to_le32(PORT_MAC_CFG_REQ_ENABLES_PTP_FREQ_ADJ_PPB);
+ rc = hwrm_req_send(ptp->bp, req);
+ if (rc)
+ netdev_err(ptp->bp->dev,
+ "ptp adjfreq failed. rc = %d\n", rc);
+ }
return rc;
}
@@ -846,8 +866,9 @@ static void bnxt_ptp_timecounter_init(struct bnxt *bp, bool init_tc)
memset(&ptp->cc, 0, sizeof(ptp->cc));
ptp->cc.read = bnxt_cc_read;
ptp->cc.mask = CYCLECOUNTER_MASK(48);
- ptp->cc.shift = 0;
- ptp->cc.mult = 1;
+ ptp->cc.shift = BNXT_CYCLES_SHIFT;
+ ptp->cc.mult = clocksource_khz2mult(BNXT_DEVCLK_FREQ, ptp->cc.shift);
+ ptp->cmult = ptp->cc.mult;
ptp->next_overflow_check = jiffies + BNXT_PHC_OVERFLOW_PERIOD;
}
if (init_tc)
diff --git a/drivers/net/ethernet/broadcom/bnxt/bnxt_ptp.h b/drivers/net/ethernet/broadcom/bnxt/bnxt_ptp.h
index 4ce0a14c1e23..34162e07a119 100644
--- a/drivers/net/ethernet/broadcom/bnxt/bnxt_ptp.h
+++ b/drivers/net/ethernet/broadcom/bnxt/bnxt_ptp.h
@@ -17,6 +17,8 @@
#define BNXT_PTP_GRC_WIN_BASE 0x6000
#define BNXT_MAX_PHC_DRIFT 31000000
+#define BNXT_CYCLES_SHIFT 23
+#define BNXT_DEVCLK_FREQ 1000000
#define BNXT_LO_TIMER_MASK 0x0000ffffffffUL
#define BNXT_HI_TIMER_MASK 0xffff00000000UL
@@ -88,8 +90,9 @@ struct bnxt_ptp_cfg {
u64 old_time;
unsigned long next_period;
unsigned long next_overflow_check;
- /* 48-bit PHC overflows in 78 hours. Check overflow every 19 hours. */
- #define BNXT_PHC_OVERFLOW_PERIOD (19 * 3600 * HZ)
+ u32 cmult;
+ /* a 23b shift cyclecounter will overflow in ~36 mins. Check overflow every 18 mins. */
+ #define BNXT_PHC_OVERFLOW_PERIOD (18 * 60 * HZ)
u16 tx_seqid;
u16 tx_hdr_off;
--
2.18.1
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