| Message ID | 20200927195659.4951-1-W_Armin@gmx.de |
|---|---|
| State | New |
| Headers | show |
| Series | [net-next] lib8390: Replace panic() call with BUILD_BUG_ON | expand |
From: Armin Wolf <W_Armin@gmx.de> Date: Sun, 27 Sep 2020 21:56:59 +0200 > Replace panic() call in lib8390.c with BUILD_BUG_ON() > since checking the size of struct e8390_pkt_hdr should > happen at compile-time. Also add __packed to e8390_pkt_hdr > to prevent padding. > > Signed-off-by: Armin Wolf <W_Armin@gmx.de> > --- > drivers/net/ethernet/8390/8390.h | 2 +- > drivers/net/ethernet/8390/lib8390.c | 4 ++-- > 2 files changed, 3 insertions(+), 3 deletions(-) > > diff --git a/drivers/net/ethernet/8390/8390.h b/drivers/net/ethernet/8390/8390.h > index e52264465998..e7d6fd55f6a5 100644 > --- a/drivers/net/ethernet/8390/8390.h > +++ b/drivers/net/ethernet/8390/8390.h > @@ -21,7 +21,7 @@ struct e8390_pkt_hdr { > unsigned char status; /* status */ > unsigned char next; /* pointer to next packet. */ > unsigned short count; /* header + packet length in bytes */ > -}; > +} __packed; This is completely unnecessary and hurts performance on some cpus as __packed forces the compiler to be unable to assume the alignment of any member of said data structure. I'm not applying this.
diff --git a/drivers/net/ethernet/8390/8390.h b/drivers/net/ethernet/8390/8390.h index e52264465998..e7d6fd55f6a5 100644 --- a/drivers/net/ethernet/8390/8390.h +++ b/drivers/net/ethernet/8390/8390.h @@ -21,7 +21,7 @@ struct e8390_pkt_hdr { unsigned char status; /* status */ unsigned char next; /* pointer to next packet. */ unsigned short count; /* header + packet length in bytes */ -}; +} __packed; #ifdef CONFIG_NET_POLL_CONTROLLER void ei_poll(struct net_device *dev); diff --git a/drivers/net/ethernet/8390/lib8390.c b/drivers/net/ethernet/8390/lib8390.c index 1f48d7f6365c..deba94d2c909 100644 --- a/drivers/net/ethernet/8390/lib8390.c +++ b/drivers/net/ethernet/8390/lib8390.c @@ -50,6 +50,7 @@ */ +#include <linux/build_bug.h> #include <linux/module.h> #include <linux/kernel.h> #include <linux/jiffies.h> @@ -1018,8 +1019,7 @@ static void __NS8390_init(struct net_device *dev, int startp) ? (0x48 | ENDCFG_WTS | (ei_local->bigendian ? ENDCFG_BOS : 0)) : 0x48; - if (sizeof(struct e8390_pkt_hdr) != 4) - panic("8390.c: header struct mispacked\n"); + BUILD_BUG_ON(sizeof(struct e8390_pkt_hdr) != 4); /* Follow National Semi's recommendations for initing the DP83902. */ ei_outb_p(E8390_NODMA+E8390_PAGE0+E8390_STOP, e8390_base+E8390_CMD); /* 0x21 */ ei_outb_p(endcfg, e8390_base + EN0_DCFG); /* 0x48 or 0x49 */
Replace panic() call in lib8390.c with BUILD_BUG_ON() since checking the size of struct e8390_pkt_hdr should happen at compile-time. Also add __packed to e8390_pkt_hdr to prevent padding. Signed-off-by: Armin Wolf <W_Armin@gmx.de> --- drivers/net/ethernet/8390/8390.h | 2 +- drivers/net/ethernet/8390/lib8390.c | 4 ++-- 2 files changed, 3 insertions(+), 3 deletions(-) -- 2.20.1