[PATCH net-next v3] net: enetc: Replace ifdef with IS_ENABLED

[PATCH net-next v3] net: enetc: Replace ifdef with IS_ENABLED

[Martyn Welch]

The enetc driver uses ifdefs when checking whether
CONFIG_FSL_ENETC_PTP_CLOCK is enabled in a number of places. This works
if the driver is compiled in but fails if the driver is available as a
kernel module. Replace the instances of ifdef with use of the IS_ENABLED
macro, that will evaluate as true when this feature is built as a kernel
module and follows the kernel's coding style.

Signed-off-by: Martyn Welch <martyn.welch@collabora.com>
Reviewed-by: Vadim Fedorenko <vadim.fedorenko@linux.dev>
---

Changes since v1:
  - Switched from preprocessor conditionals to normal C conditionals.

Changes since v2:
  - Reworked enetc_ethtool.c changes to fit around changes merged in
    net-next.

 drivers/net/ethernet/freescale/enetc/enetc.c  | 34 +++++++++----------
 drivers/net/ethernet/freescale/enetc/enetc.h  |  9 ++---
 .../ethernet/freescale/enetc/enetc_ethtool.c  | 12 ++++---
 3 files changed, 27 insertions(+), 28 deletions(-)

diff --git a/drivers/net/ethernet/freescale/enetc/enetc.c b/drivers/net/ethernet/freescale/enetc/enetc.c
index 5c45f42232d3..361464a5b6c4 100644
--- a/drivers/net/ethernet/freescale/enetc/enetc.c
+++ b/drivers/net/ethernet/freescale/enetc/enetc.c
@@ -977,10 +977,9 @@ static int enetc_refill_rx_ring(struct enetc_bdr *rx_ring, const int buff_cnt)
 	return j;
 }
 
-#ifdef CONFIG_FSL_ENETC_PTP_CLOCK
-static void enetc_get_rx_tstamp(struct net_device *ndev,
-				union enetc_rx_bd *rxbd,
-				struct sk_buff *skb)
+static void __maybe_unused enetc_get_rx_tstamp(struct net_device *ndev,
+					       union enetc_rx_bd *rxbd,
+					       struct sk_buff *skb)
 {
 	struct skb_shared_hwtstamps *shhwtstamps = skb_hwtstamps(skb);
 	struct enetc_ndev_priv *priv = netdev_priv(ndev);
@@ -1001,7 +1000,6 @@ static void enetc_get_rx_tstamp(struct net_device *ndev,
 		shhwtstamps->hwtstamp = ns_to_ktime(tstamp);
 	}
 }
-#endif
 
 static void enetc_get_offloads(struct enetc_bdr *rx_ring,
 			       union enetc_rx_bd *rxbd, struct sk_buff *skb)
@@ -1041,10 +1039,9 @@ static void enetc_get_offloads(struct enetc_bdr *rx_ring,
 		__vlan_hwaccel_put_tag(skb, tpid, le16_to_cpu(rxbd->r.vlan_opt));
 	}
 
-#ifdef CONFIG_FSL_ENETC_PTP_CLOCK
-	if (priv->active_offloads & ENETC_F_RX_TSTAMP)
+	if (IS_ENABLED(CONFIG_FSL_ENETC_PTP_CLOCK) &&
+	    (priv->active_offloads & ENETC_F_RX_TSTAMP))
 		enetc_get_rx_tstamp(rx_ring->ndev, rxbd, skb);
-#endif
 }
 
 /* This gets called during the non-XDP NAPI poll cycle as well as on XDP_PASS,
@@ -2882,8 +2879,8 @@ void enetc_set_features(struct net_device *ndev, netdev_features_t features)
 }
 EXPORT_SYMBOL_GPL(enetc_set_features);
 
-#ifdef CONFIG_FSL_ENETC_PTP_CLOCK
-static int enetc_hwtstamp_set(struct net_device *ndev, struct ifreq *ifr)
+static int __maybe_unused enetc_hwtstamp_set(struct net_device *ndev,
+					     struct ifreq *ifr)
 {
 	struct enetc_ndev_priv *priv = netdev_priv(ndev);
 	int err, new_offloads = priv->active_offloads;
@@ -2931,7 +2928,8 @@ static int enetc_hwtstamp_set(struct net_device *ndev, struct ifreq *ifr)
 	       -EFAULT : 0;
 }
 
-static int enetc_hwtstamp_get(struct net_device *ndev, struct ifreq *ifr)
+static int __maybe_unused enetc_hwtstamp_get(struct net_device *ndev,
+					     struct ifreq *ifr)
 {
 	struct enetc_ndev_priv *priv = netdev_priv(ndev);
 	struct hwtstamp_config config;
@@ -2951,17 +2949,17 @@ static int enetc_hwtstamp_get(struct net_device *ndev, struct ifreq *ifr)
 	return copy_to_user(ifr->ifr_data, &config, sizeof(config)) ?
 	       -EFAULT : 0;
 }
-#endif
 
 int enetc_ioctl(struct net_device *ndev, struct ifreq *rq, int cmd)
 {
 	struct enetc_ndev_priv *priv = netdev_priv(ndev);
-#ifdef CONFIG_FSL_ENETC_PTP_CLOCK
-	if (cmd == SIOCSHWTSTAMP)
-		return enetc_hwtstamp_set(ndev, rq);
-	if (cmd == SIOCGHWTSTAMP)
-		return enetc_hwtstamp_get(ndev, rq);
-#endif
+
+	if (IS_ENABLED(CONFIG_FSL_ENETC_PTP_CLOCK)) {
+		if (cmd == SIOCSHWTSTAMP)
+			return enetc_hwtstamp_set(ndev, rq);
+		if (cmd == SIOCGHWTSTAMP)
+			return enetc_hwtstamp_get(ndev, rq);
+	}
 
 	if (!priv->phylink)
 		return -EOPNOTSUPP;
diff --git a/drivers/net/ethernet/freescale/enetc/enetc.h b/drivers/net/ethernet/freescale/enetc/enetc.h
index a9c2ff22431c..97524dfa234c 100644
--- a/drivers/net/ethernet/freescale/enetc/enetc.h
+++ b/drivers/net/ethernet/freescale/enetc/enetc.h
@@ -184,10 +184,9 @@ static inline union enetc_rx_bd *enetc_rxbd(struct enetc_bdr *rx_ring, int i)
 {
 	int hw_idx = i;
 
-#ifdef CONFIG_FSL_ENETC_PTP_CLOCK
-	if (rx_ring->ext_en)
+	if (IS_ENABLED(CONFIG_FSL_ENETC_PTP_CLOCK) && rx_ring->ext_en)
 		hw_idx = 2 * i;
-#endif
+
 	return &(((union enetc_rx_bd *)rx_ring->bd_base)[hw_idx]);
 }
 
@@ -199,10 +198,8 @@ static inline void enetc_rxbd_next(struct enetc_bdr *rx_ring,
 
 	new_rxbd++;
 
-#ifdef CONFIG_FSL_ENETC_PTP_CLOCK
-	if (rx_ring->ext_en)
+	if (IS_ENABLED(CONFIG_FSL_ENETC_PTP_CLOCK) && rx_ring->ext_en)
 		new_rxbd++;
-#endif
 
 	if (unlikely(++new_index == rx_ring->bd_count)) {
 		new_rxbd = rx_ring->bd_base;
diff --git a/drivers/net/ethernet/freescale/enetc/enetc_ethtool.c b/drivers/net/ethernet/freescale/enetc/enetc_ethtool.c
index 47c478e08d44..2563eb8ac7b6 100644
--- a/drivers/net/ethernet/freescale/enetc/enetc_ethtool.c
+++ b/drivers/net/ethernet/freescale/enetc/enetc_ethtool.c
@@ -851,7 +851,12 @@ static int enetc_get_ts_info(struct net_device *ndev,
 		symbol_put(enetc_phc_index);
 	}
 
-#ifdef CONFIG_FSL_ENETC_PTP_CLOCK
+	if (!IS_ENABLED(CONFIG_FSL_ENETC_PTP_CLOCK)) {
+		info->so_timestamping = SOF_TIMESTAMPING_TX_SOFTWARE;
+
+		return 0;
+	}
+
 	info->so_timestamping = SOF_TIMESTAMPING_TX_HARDWARE |
 				SOF_TIMESTAMPING_RX_HARDWARE |
 				SOF_TIMESTAMPING_RAW_HARDWARE |
@@ -860,11 +865,10 @@ static int enetc_get_ts_info(struct net_device *ndev,
 	info->tx_types = (1 << HWTSTAMP_TX_OFF) |
 			 (1 << HWTSTAMP_TX_ON) |
 			 (1 << HWTSTAMP_TX_ONESTEP_SYNC);
+
 	info->rx_filters = (1 << HWTSTAMP_FILTER_NONE) |
 			   (1 << HWTSTAMP_FILTER_ALL);
-#else
-	info->so_timestamping = SOF_TIMESTAMPING_TX_SOFTWARE;
-#endif
+
 	return 0;
 }
 
-- 
2.45.2

Re: [PATCH net-next v3] net: enetc: Replace ifdef with IS_ENABLED

[Vadim Fedorenko]

On 04/09/2024 11:51, Martyn Welch wrote:
> The enetc driver uses ifdefs when checking whether
> CONFIG_FSL_ENETC_PTP_CLOCK is enabled in a number of places. This works
> if the driver is compiled in but fails if the driver is available as a
> kernel module. Replace the instances of ifdef with use of the IS_ENABLED
> macro, that will evaluate as true when this feature is built as a kernel
> module and follows the kernel's coding style.
> 
> Signed-off-by: Martyn Welch <martyn.welch@collabora.com>
> Reviewed-by: Vadim Fedorenko <vadim.fedorenko@linux.dev>

If there will be v4, please, put yours SoB as the last tag after all
other tags.

Thanks,
Vadim

Re: [PATCH net-next v3] net: enetc: Replace ifdef with IS_ENABLED

[Vladimir Oltean]

On Wed, Sep 04, 2024 at 12:11:31PM +0100, Vadim Fedorenko wrote:
> On 04/09/2024 11:51, Martyn Welch wrote:
> > The enetc driver uses ifdefs when checking whether
> > CONFIG_FSL_ENETC_PTP_CLOCK is enabled in a number of places. This works
> > if the driver is compiled in but fails if the driver is available as a
> > kernel module. Replace the instances of ifdef with use of the IS_ENABLED
> > macro, that will evaluate as true when this feature is built as a kernel
> > module and follows the kernel's coding style.
> > 
> > Signed-off-by: Martyn Welch <martyn.welch@collabora.com>
> > Reviewed-by: Vadim Fedorenko <vadim.fedorenko@linux.dev>
> 
> If there will be v4, please, put yours SoB as the last tag after all
> other tags.
> 
> Thanks,
> Vadim

What's the deal with this? If I give my review tag now, and the patch
will subsequently be applied, my Reviewed-by: tag will also appear after
his SoB.

Re: [PATCH net-next v3] net: enetc: Replace ifdef with IS_ENABLED

[Vadim Fedorenko]

On 04/09/2024 12:13, Vladimir Oltean wrote:
> On Wed, Sep 04, 2024 at 12:11:31PM +0100, Vadim Fedorenko wrote:
>> On 04/09/2024 11:51, Martyn Welch wrote:
>>> The enetc driver uses ifdefs when checking whether
>>> CONFIG_FSL_ENETC_PTP_CLOCK is enabled in a number of places. This works
>>> if the driver is compiled in but fails if the driver is available as a
>>> kernel module. Replace the instances of ifdef with use of the IS_ENABLED
>>> macro, that will evaluate as true when this feature is built as a kernel
>>> module and follows the kernel's coding style.
>>>
>>> Signed-off-by: Martyn Welch <martyn.welch@collabora.com>
>>> Reviewed-by: Vadim Fedorenko <vadim.fedorenko@linux.dev>
>>
>> If there will be v4, please, put yours SoB as the last tag after all
>> other tags.
>>
>> Thanks,
>> Vadim
> 
> What's the deal with this? If I give my review tag now, and the patch
> will subsequently be applied, my Reviewed-by: tag will also appear after
> his SoB.

I think it was discussed several times on the mailing list already,
the latest discussion was recently in this thread:
https://lore.kernel.org/netdev/20240903072417.GN23170@kernel.org/

But I have also seen this suggestion from different maintainers.
As you said that if the patch will be applied the tags will go in
historical order. In case of re-submission, historically Reviewed-by
will be earlier in time line, so should be before SoB, AFAIU.

Thanks,
Vadim

Re: [PATCH net-next v3] net: enetc: Replace ifdef with IS_ENABLED

[Vladimir Oltean]

On Wed, Sep 04, 2024 at 11:51:41AM +0100, Martyn Welch wrote:
> The enetc driver uses ifdefs when checking whether
> CONFIG_FSL_ENETC_PTP_CLOCK is enabled in a number of places. This works
> if the driver is compiled in but fails if the driver is available as a
> kernel module. Replace the instances of ifdef with use of the IS_ENABLED
> macro, that will evaluate as true when this feature is built as a kernel
> module and follows the kernel's coding style.
> 
> Signed-off-by: Martyn Welch <martyn.welch@collabora.com>
> Reviewed-by: Vadim Fedorenko <vadim.fedorenko@linux.dev>
> ---

Reviewed-by: Vladimir Oltean <vladimir.oltean@nxp.com>

Re: [PATCH net-next v3] net: enetc: Replace ifdef with IS_ENABLED

[Jakub Kicinski]

On Wed,  4 Sep 2024 11:51:41 +0100 Martyn Welch wrote:
> -#ifdef CONFIG_FSL_ENETC_PTP_CLOCK
> -static void enetc_get_rx_tstamp(struct net_device *ndev,
> -				union enetc_rx_bd *rxbd,
> -				struct sk_buff *skb)
> +static void __maybe_unused enetc_get_rx_tstamp(struct net_device *ndev,
> +					       union enetc_rx_bd *rxbd,
> +					       struct sk_buff *skb)

Are you sure you need the __maybe_used's ?
Nice thing about the IS_ENABLED() is that the code is still visible to
the compiler, even if dead code elimination removes it the compiler
shouldn't really warn about unused code.
-- 
pw-bot: cr

Re: [PATCH net-next v3] net: enetc: Replace ifdef with IS_ENABLED

[Martyn Welch]

On Fri, 2024-09-06 at 18:20 -0700, Jakub Kicinski wrote:
> On Wed,  4 Sep 2024 11:51:41 +0100 Martyn Welch wrote:
> > -#ifdef CONFIG_FSL_ENETC_PTP_CLOCK
> > -static void enetc_get_rx_tstamp(struct net_device *ndev,
> > -				union enetc_rx_bd *rxbd,
> > -				struct sk_buff *skb)
> > +static void __maybe_unused enetc_get_rx_tstamp(struct net_device
> > *ndev,
> > +					       union enetc_rx_bd
> > *rxbd,
> > +					       struct sk_buff
> > *skb)
> 
> Are you sure you need the __maybe_used's ?
> Nice thing about the IS_ENABLED() is that the code is still visible
> to
> the compiler, even if dead code elimination removes it the compiler
> shouldn't really warn about unused code.

Hi Jakub,

I thought that was required, but upon re-reading the Linux kernel
coding style documentation on the subject, I see that I miss-
understood. I will check and see.

Martyn