From patchwork Fri Oct 25 19:47:53 2024 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Vadim Fedorenko X-Patchwork-Id: 13851487 X-Patchwork-Delegate: kuba@kernel.org Received: from mx0a-00082601.pphosted.com (mx0a-00082601.pphosted.com [67.231.145.42]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by smtp.subspace.kernel.org (Postfix) with ESMTPS id 093141B07D4 for ; Fri, 25 Oct 2024 19:48:32 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=67.231.145.42 ARC-Seal: i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1729885715; cv=none; b=YvAuVu99x70zIAHVLC8yVzXv7BXhw9Ke1rIirq/KYXpxRj09SNbhSYinfiGOUTViS9muSTa8jpdxIddWEpm59cHo6/2YWAtxqbCDJ4t7qlonytkWWzJmGtExlNDkZBbmpYAIBP8qflaX4DfrW3k+FsDTJbqOLBrKZmvQn6COoSE= ARC-Message-Signature: i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1729885715; c=relaxed/simple; bh=dGBfjG8ggJmUcTXlvm0QZPyj5SkI3yFpYLX8m0Oo55Y=; h=From:To:CC:Subject:Date:Message-ID:In-Reply-To:References: MIME-Version:Content-Type; b=jHhywXvAZwe/7l7CxFimkwLh7rmkWsNu9nRkysD8s7B3ZEZYtijUnVnUF4flUQbUQrhSCyQTuDf0YQTC7r/pTTY9HRArN9XRUMd6YlVufxOtDBxFpgEbellQEDYl32uffqpIKS5JxpT8s0EJg01QuP7UAIgD/sa629VOCFsWUhw= ARC-Authentication-Results: i=1; smtp.subspace.kernel.org; dmarc=pass (p=reject dis=none) header.from=meta.com; spf=pass smtp.mailfrom=meta.com; dkim=pass (2048-bit key) header.d=meta.com header.i=@meta.com header.b=SdH1llf0; arc=none smtp.client-ip=67.231.145.42 Authentication-Results: smtp.subspace.kernel.org; dmarc=pass (p=reject dis=none) header.from=meta.com Authentication-Results: smtp.subspace.kernel.org; spf=pass smtp.mailfrom=meta.com Authentication-Results: smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=meta.com header.i=@meta.com header.b="SdH1llf0" Received: from pps.filterd (m0148461.ppops.net [127.0.0.1]) by mx0a-00082601.pphosted.com (8.18.1.2/8.18.1.2) with ESMTP id 49PJ5LE6015903; Fri, 25 Oct 2024 12:48:20 -0700 DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=meta.com; h=cc :content-transfer-encoding:content-type:date:from:in-reply-to :message-id:mime-version:references:subject:to; s=s2048-2021-q4; bh=4yPFaBtKGefKagURgm4Ye0CoZ/9fggfVEEvMvBQ+n3I=; b=SdH1llf0hO0A D+7uylop7aU5yUQdwKRacfwKsMy7iXZ7tSzQnVtLSyuYQM7zKo5MW5AhpiSDlcck Kzc/f8GLhJzbF7I7f6SEbEADmHCjGg7EXZfJpmy5OqB/sK1i91ohPW0QAyOPBYrC y7WZL12g6c5M8GxtIsGr7nTn9oNNqcUa8sXBLxAl1B2B5v1vWQESxOgzsovebUY2 u96cxjRmxibYwI+Ph+cZv5pVWmLpAZO+hRdnAYKFuqqw8v6Gr8ofqwBWTIw6I0vC ol4tFwJXnC7QTm0fbLo04tQbdS84xuz0zA6wovNaj0SllW4/Aa7m/koza8Y62La8 2FdwaZqxLA== Received: from maileast.thefacebook.com ([163.114.135.16]) by mx0a-00082601.pphosted.com (PPS) with ESMTPS id 42gg1rrtnw-2 (version=TLSv1.2 cipher=ECDHE-RSA-AES128-GCM-SHA256 bits=128 verify=NOT); Fri, 25 Oct 2024 12:48:20 -0700 (PDT) Received: from devvm4158.cln0.facebook.com (2620:10d:c0a8:1c::11) by mail.thefacebook.com (2620:10d:c0a9:6f::237c) with Microsoft SMTP Server id 15.2.1544.11; Fri, 25 Oct 2024 19:48:18 +0000 From: Vadim Fedorenko To: Vadim Fedorenko , Michael Chan , Pavan Chebbi , "Jakub Kicinski" CC: Andrew Lunn , Paolo Abeni , "David S. Miller" , , "Richard Cochran" , Vadim Fedorenko Subject: [PATCH net-next v2 2/2] bnxt_en: replace PTP spinlock with seqlock Date: Fri, 25 Oct 2024 12:47:53 -0700 Message-ID: <20241025194753.3070604-2-vadfed@meta.com> X-Mailer: git-send-email 2.43.5 In-Reply-To: <20241025194753.3070604-1-vadfed@meta.com> References: <20241025194753.3070604-1-vadfed@meta.com> Precedence: bulk X-Mailing-List: netdev@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 X-Proofpoint-GUID: iSb-lI3bcxodIAMJJ4LRWX84OMaYYu0j X-Proofpoint-ORIG-GUID: iSb-lI3bcxodIAMJJ4LRWX84OMaYYu0j X-Proofpoint-Virus-Version: vendor=baseguard engine=ICAP:2.0.293,Aquarius:18.0.1051,Hydra:6.0.680,FMLib:17.12.62.30 definitions=2024-10-05_03,2024-10-04_01,2024-09-30_01 X-Patchwork-Delegate: kuba@kernel.org We can see high contention on ptp_lock while doing RX timestamping on high packet rates over several queues. Spinlock is not effecient to protect timecounter for RX timestamps when reads are the most usual operations and writes are only occasional. It's better to use seqlock in such cases. Signed-off-by: Vadim Fedorenko --- v2: - use read_excl lock to serialize reg access with FW reset --- drivers/net/ethernet/broadcom/bnxt/bnxt.c | 18 ++--- drivers/net/ethernet/broadcom/bnxt/bnxt_ptp.c | 73 ++++++------------- drivers/net/ethernet/broadcom/bnxt/bnxt_ptp.h | 14 +++- 3 files changed, 46 insertions(+), 59 deletions(-) diff --git a/drivers/net/ethernet/broadcom/bnxt/bnxt.c b/drivers/net/ethernet/broadcom/bnxt/bnxt.c index 6dd6541d8619..f5ddd01c78eb 100644 --- a/drivers/net/ethernet/broadcom/bnxt/bnxt.c +++ b/drivers/net/ethernet/broadcom/bnxt/bnxt.c @@ -2256,9 +2256,7 @@ static int bnxt_rx_pkt(struct bnxt *bp, struct bnxt_cp_ring_info *cpr, struct bnxt_ptp_cfg *ptp = bp->ptp_cfg; unsigned long flags; - spin_lock_irqsave(&ptp->ptp_lock, flags); - ns = timecounter_cyc2time(&ptp->tc, ts); - spin_unlock_irqrestore(&ptp->ptp_lock, flags); + ns = bnxt_timecounter_cyc2time(ptp, ts); memset(skb_hwtstamps(skb), 0, sizeof(*skb_hwtstamps(skb))); skb_hwtstamps(skb)->hwtstamp = ns_to_ktime(ns); @@ -2764,12 +2762,12 @@ static int bnxt_async_event_process(struct bnxt *bp, if (!ptp) goto async_event_process_exit; - spin_lock_irqsave(&ptp->ptp_lock, flags); bnxt_ptp_update_current_time(bp); ns = (((u64)BNXT_EVENT_PHC_RTC_UPDATE(data1) << BNXT_PHC_BITS) | ptp->current_time); + write_seqlock_irqsave(&ptp->ptp_lock, flags); bnxt_ptp_rtc_timecounter_init(ptp, ns); - spin_unlock_irqrestore(&ptp->ptp_lock, flags); + write_sequnlock_irqrestore(&ptp->ptp_lock, flags); } break; } @@ -13496,12 +13494,13 @@ static void bnxt_force_fw_reset(struct bnxt *bp) test_bit(BNXT_STATE_IN_FW_RESET, &bp->state)) return; + /* we have to serialize with bnxt_refclk_read()*/ if (ptp) { unsigned long flags; - spin_lock_irqsave(&ptp->ptp_lock, flags); + write_seqlock_irqsave(&ptp->ptp_lock, flags); set_bit(BNXT_STATE_IN_FW_RESET, &bp->state); - spin_unlock_irqrestore(&ptp->ptp_lock, flags); + write_sequnlock_irqrestore(&ptp->ptp_lock, flags); } else { set_bit(BNXT_STATE_IN_FW_RESET, &bp->state); } @@ -13565,12 +13564,13 @@ void bnxt_fw_reset(struct bnxt *bp) struct bnxt_ptp_cfg *ptp = bp->ptp_cfg; int n = 0, tmo; + /* we have to serialize with bnxt_refclk_read()*/ if (ptp) { unsigned long flags; - spin_lock_irqsave(&ptp->ptp_lock, flags); + write_seqlock_irqsave(&ptp->ptp_lock, flags); set_bit(BNXT_STATE_IN_FW_RESET, &bp->state); - spin_unlock_irqrestore(&ptp->ptp_lock, flags); + write_sequnlock_irqrestore(&ptp->ptp_lock, flags); } else { set_bit(BNXT_STATE_IN_FW_RESET, &bp->state); } diff --git a/drivers/net/ethernet/broadcom/bnxt/bnxt_ptp.c b/drivers/net/ethernet/broadcom/bnxt/bnxt_ptp.c index c7e626b9098a..6c507fd5689c 100644 --- a/drivers/net/ethernet/broadcom/bnxt/bnxt_ptp.c +++ b/drivers/net/ethernet/broadcom/bnxt/bnxt_ptp.c @@ -67,19 +67,21 @@ static int bnxt_ptp_settime(struct ptp_clock_info *ptp_info, if (BNXT_PTP_USE_RTC(ptp->bp)) return bnxt_ptp_cfg_settime(ptp->bp, ns); - spin_lock_irqsave(&ptp->ptp_lock, flags); + write_seqlock_irqsave(&ptp->ptp_lock, flags); timecounter_init(&ptp->tc, &ptp->cc, ns); - spin_unlock_irqrestore(&ptp->ptp_lock, flags); + write_sequnlock_irqrestore(&ptp->ptp_lock, flags); return 0; } -/* Caller holds ptp_lock */ static int bnxt_refclk_read(struct bnxt *bp, struct ptp_system_timestamp *sts, u64 *ns) { struct bnxt_ptp_cfg *ptp = bp->ptp_cfg; u32 high_before, high_now, low; + unsigned long flags; + /* We have to serialize reg access and FW reset */ + read_seqlock_excl_irqsave(&ptp->ptp_lock, flags); if (test_bit(BNXT_STATE_IN_FW_RESET, &bp->state)) return -EIO; @@ -93,6 +95,7 @@ static int bnxt_refclk_read(struct bnxt *bp, struct ptp_system_timestamp *sts, low = readl(bp->bar0 + ptp->refclk_mapped_regs[0]); ptp_read_system_postts(sts); } + read_sequnlock_excl_irqrestore(&ptp->ptp_lock, flags); *ns = ((u64)high_now << 32) | low; return 0; @@ -101,14 +104,11 @@ static int bnxt_refclk_read(struct bnxt *bp, struct ptp_system_timestamp *sts, static void bnxt_ptp_get_current_time(struct bnxt *bp) { struct bnxt_ptp_cfg *ptp = bp->ptp_cfg; - unsigned long flags; if (!ptp) return; - spin_lock_irqsave(&ptp->ptp_lock, flags); WRITE_ONCE(ptp->old_time, (u32)(ptp->current_time >> 24)); bnxt_refclk_read(bp, NULL, &ptp->current_time); - spin_unlock_irqrestore(&ptp->ptp_lock, flags); } static int bnxt_hwrm_port_ts_query(struct bnxt *bp, u32 flags, u64 *ts, @@ -151,24 +151,19 @@ static int bnxt_ptp_gettimex(struct ptp_clock_info *ptp_info, { struct bnxt_ptp_cfg *ptp = container_of(ptp_info, struct bnxt_ptp_cfg, ptp_info); - unsigned long flags; u64 ns, cycles; int rc; - spin_lock_irqsave(&ptp->ptp_lock, flags); rc = bnxt_refclk_read(ptp->bp, sts, &cycles); - if (rc) { - spin_unlock_irqrestore(&ptp->ptp_lock, flags); + if (rc) return rc; - } - ns = timecounter_cyc2time(&ptp->tc, cycles); - spin_unlock_irqrestore(&ptp->ptp_lock, flags); + + ns = bnxt_timecounter_cyc2time(ptp, cycles); *ts = ns_to_timespec64(ns); return 0; } -/* Caller holds ptp_lock */ void bnxt_ptp_update_current_time(struct bnxt *bp) { struct bnxt_ptp_cfg *ptp = bp->ptp_cfg; @@ -180,7 +175,6 @@ void bnxt_ptp_update_current_time(struct bnxt *bp) static int bnxt_ptp_adjphc(struct bnxt_ptp_cfg *ptp, s64 delta) { struct hwrm_port_mac_cfg_input *req; - unsigned long flags; int rc; rc = hwrm_req_init(ptp->bp, req, HWRM_PORT_MAC_CFG); @@ -194,9 +188,7 @@ static int bnxt_ptp_adjphc(struct bnxt_ptp_cfg *ptp, s64 delta) if (rc) { netdev_err(ptp->bp->dev, "ptp adjphc failed. rc = %x\n", rc); } else { - spin_lock_irqsave(&ptp->ptp_lock, flags); bnxt_ptp_update_current_time(ptp->bp); - spin_unlock_irqrestore(&ptp->ptp_lock, flags); } return rc; @@ -211,9 +203,9 @@ static int bnxt_ptp_adjtime(struct ptp_clock_info *ptp_info, s64 delta) if (BNXT_PTP_USE_RTC(ptp->bp)) return bnxt_ptp_adjphc(ptp, delta); - spin_lock_irqsave(&ptp->ptp_lock, flags); + write_seqlock_irqsave(&ptp->ptp_lock, flags); timecounter_adjtime(&ptp->tc, delta); - spin_unlock_irqrestore(&ptp->ptp_lock, flags); + write_sequnlock_irqrestore(&ptp->ptp_lock, flags); return 0; } @@ -246,10 +238,10 @@ static int bnxt_ptp_adjfine(struct ptp_clock_info *ptp_info, long scaled_ppm) if (!BNXT_MH(bp)) return bnxt_ptp_adjfine_rtc(bp, scaled_ppm); - spin_lock_irqsave(&ptp->ptp_lock, flags); + write_seqlock_irqsave(&ptp->ptp_lock, flags); timecounter_read(&ptp->tc); ptp->cc.mult = adjust_by_scaled_ppm(ptp->cmult, scaled_ppm); - spin_unlock_irqrestore(&ptp->ptp_lock, flags); + write_sequnlock_irqrestore(&ptp->ptp_lock, flags); return 0; } @@ -257,13 +249,10 @@ void bnxt_ptp_pps_event(struct bnxt *bp, u32 data1, u32 data2) { struct bnxt_ptp_cfg *ptp = bp->ptp_cfg; struct ptp_clock_event event; - unsigned long flags; u64 ns, pps_ts; pps_ts = EVENT_PPS_TS(data2, data1); - spin_lock_irqsave(&ptp->ptp_lock, flags); - ns = timecounter_cyc2time(&ptp->tc, pps_ts); - spin_unlock_irqrestore(&ptp->ptp_lock, flags); + ns = bnxt_timecounter_cyc2time(ptp, pps_ts); switch (EVENT_DATA2_PPS_EVENT_TYPE(data2)) { case ASYNC_EVENT_CMPL_PPS_TIMESTAMP_EVENT_DATA2_EVENT_TYPE_INTERNAL: @@ -400,17 +389,13 @@ static int bnxt_get_target_cycles(struct bnxt_ptp_cfg *ptp, u64 target_ns, { u64 cycles_now; u64 nsec_now, nsec_delta; - unsigned long flags; int rc; - spin_lock_irqsave(&ptp->ptp_lock, flags); rc = bnxt_refclk_read(ptp->bp, NULL, &cycles_now); - if (rc) { - spin_unlock_irqrestore(&ptp->ptp_lock, flags); + if (rc) return rc; - } - nsec_now = timecounter_cyc2time(&ptp->tc, cycles_now); - spin_unlock_irqrestore(&ptp->ptp_lock, flags); + + nsec_now = bnxt_timecounter_cyc2time(ptp, cycles_now); nsec_delta = target_ns - nsec_now; *cycles_delta = div64_u64(nsec_delta << ptp->cc.shift, ptp->cc.mult); @@ -697,7 +682,6 @@ static int bnxt_stamp_tx_skb(struct bnxt *bp, int slot) struct skb_shared_hwtstamps timestamp; struct bnxt_ptp_tx_req *txts_req; unsigned long now = jiffies; - unsigned long flags; u64 ts = 0, ns = 0; u32 tmo = 0; int rc; @@ -711,9 +695,7 @@ static int bnxt_stamp_tx_skb(struct bnxt *bp, int slot) tmo, slot); if (!rc) { memset(×tamp, 0, sizeof(timestamp)); - spin_lock_irqsave(&ptp->ptp_lock, flags); - ns = timecounter_cyc2time(&ptp->tc, ts); - spin_unlock_irqrestore(&ptp->ptp_lock, flags); + ns = bnxt_timecounter_cyc2time(ptp, ts); timestamp.hwtstamp = ns_to_ktime(ns); skb_tstamp_tx(txts_req->tx_skb, ×tamp); ptp->stats.ts_pkts++; @@ -767,9 +749,9 @@ static long bnxt_ptp_ts_aux_work(struct ptp_clock_info *ptp_info) bnxt_ptp_get_current_time(bp); ptp->next_period = now + HZ; if (time_after_eq(now, ptp->next_overflow_check)) { - spin_lock_irqsave(&ptp->ptp_lock, flags); + write_seqlock_irqsave(&ptp->ptp_lock, flags); timecounter_read(&ptp->tc); - spin_unlock_irqrestore(&ptp->ptp_lock, flags); + write_sequnlock_irqrestore(&ptp->ptp_lock, flags); ptp->next_overflow_check = now + BNXT_PHC_OVERFLOW_PERIOD; } if (rc == -EAGAIN) @@ -829,7 +811,6 @@ void bnxt_tx_ts_cmp(struct bnxt *bp, struct bnxt_napi *bnapi, u32 opaque = tscmp->tx_ts_cmp_opaque; struct bnxt_tx_ring_info *txr; struct bnxt_sw_tx_bd *tx_buf; - unsigned long flags; u64 ts, ns; u16 cons; @@ -844,9 +825,7 @@ void bnxt_tx_ts_cmp(struct bnxt *bp, struct bnxt_napi *bnapi, le32_to_cpu(tscmp->tx_ts_cmp_flags_type), le32_to_cpu(tscmp->tx_ts_cmp_errors_v)); } else { - spin_lock_irqsave(&ptp->ptp_lock, flags); - ns = timecounter_cyc2time(&ptp->tc, ts); - spin_unlock_irqrestore(&ptp->ptp_lock, flags); + ns = bnxt_timecounter_cyc2time(ptp, ts); timestamp.hwtstamp = ns_to_ktime(ns); skb_tstamp_tx(tx_buf->skb, ×tamp); } @@ -1005,9 +984,9 @@ int bnxt_ptp_init_rtc(struct bnxt *bp, bool phc_cfg) if (rc) return rc; } - spin_lock_irqsave(&bp->ptp_cfg->ptp_lock, flags); + write_seqlock_irqsave(&bp->ptp_cfg->ptp_lock, flags); bnxt_ptp_rtc_timecounter_init(bp->ptp_cfg, ns); - spin_unlock_irqrestore(&bp->ptp_cfg->ptp_lock, flags); + write_sequnlock_irqrestore(&bp->ptp_cfg->ptp_lock, flags); return 0; } @@ -1042,7 +1021,7 @@ int bnxt_ptp_init(struct bnxt *bp, bool phc_cfg) bnxt_ptp_free(bp); WRITE_ONCE(ptp->tx_avail, BNXT_MAX_TX_TS); - spin_lock_init(&ptp->ptp_lock); + seqlock_init(&ptp->ptp_lock); spin_lock_init(&ptp->ptp_tx_lock); if (BNXT_PTP_USE_RTC(bp)) { @@ -1075,12 +1054,8 @@ int bnxt_ptp_init(struct bnxt *bp, bool phc_cfg) atomic64_set(&ptp->stats.ts_err, 0); if (bp->flags & BNXT_FLAG_CHIP_P5_PLUS) { - unsigned long flags; - - spin_lock_irqsave(&ptp->ptp_lock, flags); bnxt_refclk_read(bp, NULL, &ptp->current_time); WRITE_ONCE(ptp->old_time, (u32)(ptp->current_time >> 24)); - spin_unlock_irqrestore(&ptp->ptp_lock, flags); ptp_schedule_worker(ptp->ptp_clock, 0); } ptp->txts_tmo = BNXT_PTP_DFLT_TX_TMO; diff --git a/drivers/net/ethernet/broadcom/bnxt/bnxt_ptp.h b/drivers/net/ethernet/broadcom/bnxt/bnxt_ptp.h index 80046bd314db..e2b401251399 100644 --- a/drivers/net/ethernet/broadcom/bnxt/bnxt_ptp.h +++ b/drivers/net/ethernet/broadcom/bnxt/bnxt_ptp.h @@ -102,7 +102,7 @@ struct bnxt_ptp_cfg { struct timecounter tc; struct bnxt_pps pps_info; /* serialize timecounter access */ - spinlock_t ptp_lock; + seqlock_t ptp_lock; /* serialize ts tx request queuing */ spinlock_t ptp_tx_lock; u64 current_time; @@ -168,4 +168,16 @@ void bnxt_ptp_rtc_timecounter_init(struct bnxt_ptp_cfg *ptp, u64 ns); int bnxt_ptp_init_rtc(struct bnxt *bp, bool phc_cfg); int bnxt_ptp_init(struct bnxt *bp, bool phc_cfg); void bnxt_ptp_clear(struct bnxt *bp); +static inline u64 bnxt_timecounter_cyc2time(struct bnxt_ptp_cfg *ptp, u64 ts) +{ + unsigned int seq; + u64 ns; + + do { + seq = read_seqbegin(&ptp->ptp_lock); + ns = timecounter_cyc2time(&ptp->tc, ts); + } while (read_seqretry(&ptp->ptp_lock, seq)); + + return ns; +} #endif