From nobody Thu Apr 2 20:37:56 2026 Received: from mail-pl1-f202.google.com (mail-pl1-f202.google.com [209.85.214.202]) (using TLSv1.2 with cipher ECDHE-RSA-AES128-GCM-SHA256 (128/128 bits)) (No client certificate requested) by smtp.subspace.kernel.org (Postfix) with ESMTPS id 4FCB2346FA6 for ; Thu, 26 Mar 2026 22:45:35 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=209.85.214.202 ARC-Seal: i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1774565136; cv=none; b=ZKpN4u+b0W9RDwEE8Vu9cfRmXXJJhj5OVFDV619zzAq2FJQhBZv8xHupAzMC+C19CeK2S1/68KZeZt8s4mw2EzC0iRbE6cJuqTe3kCiR7QgWlVFBrLcSgOz9FDPPCh7WyEsnEJ5v/jU10wHQhVRhIPUZdomdgohdWbhQH7zxmsI= ARC-Message-Signature: i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1774565136; c=relaxed/simple; bh=5Txi5dwhnQhZbwtiLFvwxvxiOL2+dETMit3sCsC05fs=; h=Date:In-Reply-To:Mime-Version:References:Message-ID:Subject:From: To:Cc:Content-Type; b=Tp4gZxMwOnZEYbYjz7UEhGNQ7H0MRPLr5i2Acd1b5dxHlEQ73lzUqEMZ5gYIgkdBfzhPHPSS4XltAr0uo8F9vqWNl6uNwcacJDIPnTKJ1Y/m6+yKKouyWDHZIYM+Y3vsI2JWgac2gGRNICL5Yn1QlKZGxvSjHDECpxa1h0pksck= ARC-Authentication-Results: i=1; smtp.subspace.kernel.org; dmarc=pass (p=reject dis=none) header.from=google.com; spf=pass smtp.mailfrom=flex--hramamurthy.bounces.google.com; dkim=pass (2048-bit key) header.d=google.com header.i=@google.com header.b=k7hmAYUf; arc=none smtp.client-ip=209.85.214.202 Authentication-Results: smtp.subspace.kernel.org; dmarc=pass (p=reject dis=none) header.from=google.com Authentication-Results: smtp.subspace.kernel.org; spf=pass smtp.mailfrom=flex--hramamurthy.bounces.google.com Authentication-Results: smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=google.com header.i=@google.com header.b="k7hmAYUf" Received: by mail-pl1-f202.google.com with SMTP id d9443c01a7336-2b068299665so17488705ad.3 for ; Thu, 26 Mar 2026 15:45:35 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=google.com; s=20251104; t=1774565135; x=1775169935; darn=vger.kernel.org; h=cc:to:from:subject:message-id:references:mime-version:in-reply-to :date:from:to:cc:subject:date:message-id:reply-to; bh=UBqjipqe1hWrqGUrEp4FoAUnPSZh4H54A4uK3kM6Occ=; b=k7hmAYUf/SkMqVS5ApGgaNZy+iSJvnwxBRUnsWNe82Grv3xHSG0djWyB+k9AzELHPo 7EbrUmLYfSiKlJaQIK5JZ4yoaq+eFnJi02RSq5His1isYkZQrwzfg45Yn7AGjmhHesDv X+rEaw+mwS1qCsAUe0xBUO9lIMfr2Pr8TMMpjmFx+8Pn/Z1IhBuMtd8msg8Cb2f1YBaj 8zb8KxYfvNtKCquCbkTXAXR6P2w+GXyau5bOC1HRNLpXWG2eROvCYb7ed+Zd6r8BTYAe MUzH6vqvE7+mOD/cHjHdnYdei41eElm0/KJM1CDvso0pSX4ueI77ya/NXD172tdJHW2+ UaSg== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20251104; t=1774565135; x=1775169935; h=cc:to:from:subject:message-id:references:mime-version:in-reply-to :date:x-gm-message-state:from:to:cc:subject:date:message-id:reply-to; bh=UBqjipqe1hWrqGUrEp4FoAUnPSZh4H54A4uK3kM6Occ=; b=blm4FkUKvaAdgG410B73JhGx0o50LA/LFweHsAFhuR9Ck/YL0EFESr1MU0he5wh8qm gaAoPaZGBB9nIns7YztwJtLXLJf90WKxDU1lesJM9HERN47HN8sZ9WjheXpQGwREEtuZ bgXUG9YQjrLsxd4Q0fRmJsmiRhsIbFX7Eu3LvWcT2OBtzWH67M+nxBy0AmDR980BO72F z0EWHb1+PLpoNrDccttzzrjharBS2NMhIK5EhUJ1rpwkHSYB5opQPoos7L8sZ3kjUbuV AEMCyi+btYStZhkMpiK1eq75iHKXTU6syxY7gVt6ZKgkG2nyIIOTYBEBZ0a0Byj8RKBe hP+w== X-Forwarded-Encrypted: i=1; AJvYcCVAif6R2lZwgVuvmUFqHYYRsqXUV5XR6Nit9xK41GdzCE6zZ6EiydG28OxTp34tEDsqSHdF3aTQYhApUwg=@vger.kernel.org X-Gm-Message-State: AOJu0YwdixoxYvw+viHS417XHOzGwzJyJy2H+feEy2CjYktUdmmmKsvf DaMJZExppVJhk0bSpMEVFMAoO3uDT5S58384aviC39KaPYfrk7Keji0EHa4gjm9i5Mgq/ChgXes veaGQuyset5H3zpzrYnphKyG4Ng== X-Received: from pgvf17.prod.google.com ([2002:a65:6291:0:b0:c73:97d4:afe0]) (user=hramamurthy job=prod-delivery.src-stubby-dispatcher) by 2002:a05:6a20:432b:b0:39b:8b8b:39ed with SMTP id adf61e73a8af0-39c87c0179fmr368442637.68.1774565134419; Thu, 26 Mar 2026 15:45:34 -0700 (PDT) Date: Thu, 26 Mar 2026 22:45:26 +0000 In-Reply-To: <20260326224527.1044097-1-hramamurthy@google.com> Precedence: bulk X-Mailing-List: linux-kernel@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: Mime-Version: 1.0 References: <20260326224527.1044097-1-hramamurthy@google.com> X-Mailer: git-send-email 2.53.0.1018.g2bb0e51243-goog Message-ID: <20260326224527.1044097-3-hramamurthy@google.com> Subject: [PATCH net-next v2 2/3] gve: make nic clock reads thread safe From: Harshitha Ramamurthy To: netdev@vger.kernel.org Cc: joshwash@google.com, hramamurthy@google.com, andrew+netdev@lunn.ch, davem@davemloft.net, edumazet@google.com, kuba@kernel.org, pabeni@redhat.com, richardcochran@gmail.com, willemb@google.com, nktgrg@google.com, jfraker@google.com, ziweixiao@google.com, maolson@google.com, thostet@google.com, jordanrhee@google.com, jefrogers@google.com, alok.a.tiwari@oracle.com, yyd@google.com, linux-kernel@vger.kernel.org Content-Transfer-Encoding: quoted-printable Content-Type: text/plain; charset="utf-8" From: Ankit Garg Add a mutex to protect the shared DMA buffer that receives NIC timestamp reports. The NIC timestamp will be read from two different threads: the periodic worker and upcoming `gettimex64`. Reviewed-by: Joshua Washington Signed-off-by: Ankit Garg Signed-off-by: Jordan Rhee Signed-off-by: Harshitha Ramamurthy --- drivers/net/ethernet/google/gve/gve.h | 6 +---- drivers/net/ethernet/google/gve/gve_ptp.c | 32 +++++++++++++++-------- 2 files changed, 22 insertions(+), 16 deletions(-) diff --git a/drivers/net/ethernet/google/gve/gve.h b/drivers/net/ethernet/g= oogle/gve/gve.h index 1d66d3834f7e..7b8f78bd1968 100644 --- a/drivers/net/ethernet/google/gve/gve.h +++ b/drivers/net/ethernet/google/gve/gve.h @@ -923,6 +923,7 @@ struct gve_priv { bool nic_timestamp_supported; struct gve_ptp *ptp; struct kernel_hwtstamp_config ts_config; + struct mutex nic_ts_read_lock; /* Protects nic_ts_report */ struct gve_nic_ts_report *nic_ts_report; dma_addr_t nic_ts_report_bus; u64 last_sync_nic_counter; /* Clock counter from last NIC TS report */ @@ -1321,14 +1322,9 @@ int gve_flow_rules_reset(struct gve_priv *priv); int gve_init_rss_config(struct gve_priv *priv, u16 num_queues); /* PTP and timestamping */ #if IS_ENABLED(CONFIG_PTP_1588_CLOCK) -int gve_clock_nic_ts_read(struct gve_priv *priv); int gve_init_clock(struct gve_priv *priv); void gve_teardown_clock(struct gve_priv *priv); #else /* CONFIG_PTP_1588_CLOCK */ -static inline int gve_clock_nic_ts_read(struct gve_priv *priv) -{ - return -EOPNOTSUPP; -} =20 static inline int gve_init_clock(struct gve_priv *priv) { diff --git a/drivers/net/ethernet/google/gve/gve_ptp.c b/drivers/net/ethern= et/google/gve/gve_ptp.c index 06b1cf4a5efc..140b8fbce4f4 100644 --- a/drivers/net/ethernet/google/gve/gve_ptp.c +++ b/drivers/net/ethernet/google/gve/gve_ptp.c @@ -11,19 +11,20 @@ #define GVE_NIC_TS_SYNC_INTERVAL_MS 250 =20 /* Read the nic timestamp from hardware via the admin queue. */ -int gve_clock_nic_ts_read(struct gve_priv *priv) +static int gve_clock_nic_ts_read(struct gve_priv *priv, u64 *nic_raw) { - u64 nic_raw; int err; =20 + mutex_lock(&priv->nic_ts_read_lock); err =3D gve_adminq_report_nic_ts(priv, priv->nic_ts_report_bus); if (err) - return err; + goto out; =20 - nic_raw =3D be64_to_cpu(priv->nic_ts_report->nic_timestamp); - WRITE_ONCE(priv->last_sync_nic_counter, nic_raw); + *nic_raw =3D be64_to_cpu(priv->nic_ts_report->nic_timestamp); =20 - return 0; +out: + mutex_unlock(&priv->nic_ts_read_lock); + return err; } =20 static int gve_ptp_gettimex64(struct ptp_clock_info *info, @@ -43,15 +44,19 @@ static long gve_ptp_do_aux_work(struct ptp_clock_info *= info) { const struct gve_ptp *ptp =3D container_of(info, struct gve_ptp, info); struct gve_priv *priv =3D ptp->priv; + u64 nic_raw; int err; =20 if (gve_get_reset_in_progress(priv) || !gve_get_admin_queue_ok(priv)) goto out; =20 - err =3D gve_clock_nic_ts_read(priv); - if (err && net_ratelimit()) - dev_err(&priv->pdev->dev, - "%s read err %d\n", __func__, err); + err =3D gve_clock_nic_ts_read(priv, &nic_raw); + if (err) { + dev_err_ratelimited(&priv->pdev->dev, "%s read err %d\n", + __func__, err); + goto out; + } + WRITE_ONCE(priv->last_sync_nic_counter, nic_raw); =20 out: return msecs_to_jiffies(GVE_NIC_TS_SYNC_INTERVAL_MS); @@ -109,6 +114,7 @@ static void gve_ptp_release(struct gve_priv *priv) =20 int gve_init_clock(struct gve_priv *priv) { + u64 nic_raw; int err; =20 err =3D gve_ptp_init(priv); @@ -125,17 +131,20 @@ int gve_init_clock(struct gve_priv *priv) err =3D -ENOMEM; goto release_ptp; } - err =3D gve_clock_nic_ts_read(priv); + mutex_init(&priv->nic_ts_read_lock); + err =3D gve_clock_nic_ts_read(priv, &nic_raw); if (err) { dev_err(&priv->pdev->dev, "failed to read NIC clock %d\n", err); goto release_nic_ts_report; } + WRITE_ONCE(priv->last_sync_nic_counter, nic_raw); ptp_schedule_worker(priv->ptp->clock, msecs_to_jiffies(GVE_NIC_TS_SYNC_INTERVAL_MS)); =20 return 0; =20 release_nic_ts_report: + mutex_destroy(&priv->nic_ts_read_lock); dma_free_coherent(&priv->pdev->dev, sizeof(struct gve_nic_ts_report), priv->nic_ts_report, priv->nic_ts_report_bus); @@ -150,6 +159,7 @@ void gve_teardown_clock(struct gve_priv *priv) gve_ptp_release(priv); =20 if (priv->nic_ts_report) { + mutex_destroy(&priv->nic_ts_read_lock); dma_free_coherent(&priv->pdev->dev, sizeof(struct gve_nic_ts_report), priv->nic_ts_report, priv->nic_ts_report_bus); --=20 2.53.0.1018.g2bb0e51243-goog