| Message ID | 20210604123018.24940-1-michael@walle.cc |
|---|---|
| State | New |
| Headers | show |
| Series | [net-next] net: enetc: use get/put_unaligned() for mac address handling | expand |
> -----Original Message----- > From: Heiner Kallweit <hkallweit1@gmail.com> > Sent: Friday, June 4, 2021 3:44 PM [...] > > On 04.06.2021 14:30, Michael Walle wrote: > > The supplied buffer for the MAC address might not be aligned. Thus > > doing a 32bit (or 16bit) access could be on an unaligned address. For > > now, enetc is only used on aarch64 which can do unaligned accesses, thus > > there is no error. In any case, be correct and use the get/put_unaligned() > > helpers. > > > > Signed-off-by: Michael Walle <michael@walle.cc> > > --- > > drivers/net/ethernet/freescale/enetc/enetc_pf.c | 9 +++++---- > > 1 file changed, 5 insertions(+), 4 deletions(-) > > > > diff --git a/drivers/net/ethernet/freescale/enetc/enetc_pf.c > b/drivers/net/ethernet/freescale/enetc/enetc_pf.c > > index 31274325159a..a96d2acb5e11 100644 > > --- a/drivers/net/ethernet/freescale/enetc/enetc_pf.c > > +++ b/drivers/net/ethernet/freescale/enetc/enetc_pf.c > > @@ -1,6 +1,7 @@ > > // SPDX-License-Identifier: (GPL-2.0+ OR BSD-3-Clause) > > /* Copyright 2017-2019 NXP */ > > > > +#include <asm/unaligned.h> > > #include <linux/mdio.h> > > #include <linux/module.h> > > #include <linux/fsl/enetc_mdio.h> > > @@ -17,15 +18,15 @@ static void enetc_pf_get_primary_mac_addr(struct > enetc_hw *hw, int si, u8 *addr) > > u32 upper = __raw_readl(hw->port + ENETC_PSIPMAR0(si)); > > u16 lower = __raw_readw(hw->port + ENETC_PSIPMAR1(si)); > > > > - *(u32 *)addr = upper; > > - *(u16 *)(addr + 4) = lower; > > + put_unaligned(upper, (u32 *)addr); > > + put_unaligned(lower, (u16 *)(addr + 4)); > > I think you want to write little endian, therefore on a BE platform > this code may be wrong. Better use put_unaligned_le32? > By using these versions of the unaligned helpers you could also > remove the pointer cast. > +1
diff --git a/drivers/net/ethernet/freescale/enetc/enetc_pf.c b/drivers/net/ethernet/freescale/enetc/enetc_pf.c index 31274325159a..a96d2acb5e11 100644 --- a/drivers/net/ethernet/freescale/enetc/enetc_pf.c +++ b/drivers/net/ethernet/freescale/enetc/enetc_pf.c @@ -1,6 +1,7 @@ // SPDX-License-Identifier: (GPL-2.0+ OR BSD-3-Clause) /* Copyright 2017-2019 NXP */ +#include <asm/unaligned.h> #include <linux/mdio.h> #include <linux/module.h> #include <linux/fsl/enetc_mdio.h> @@ -17,15 +18,15 @@ static void enetc_pf_get_primary_mac_addr(struct enetc_hw *hw, int si, u8 *addr) u32 upper = __raw_readl(hw->port + ENETC_PSIPMAR0(si)); u16 lower = __raw_readw(hw->port + ENETC_PSIPMAR1(si)); - *(u32 *)addr = upper; - *(u16 *)(addr + 4) = lower; + put_unaligned(upper, (u32 *)addr); + put_unaligned(lower, (u16 *)(addr + 4)); } static void enetc_pf_set_primary_mac_addr(struct enetc_hw *hw, int si, const u8 *addr) { - u32 upper = *(const u32 *)addr; - u16 lower = *(const u16 *)(addr + 4); + u32 upper = get_unaligned((const u32 *)addr); + u16 lower = get_unaligned((const u16 *)(addr + 4)); __raw_writel(upper, hw->port + ENETC_PSIPMAR0(si)); __raw_writew(lower, hw->port + ENETC_PSIPMAR1(si));
The supplied buffer for the MAC address might not be aligned. Thus doing a 32bit (or 16bit) access could be on an unaligned address. For now, enetc is only used on aarch64 which can do unaligned accesses, thus there is no error. In any case, be correct and use the get/put_unaligned() helpers. Signed-off-by: Michael Walle <michael@walle.cc> --- drivers/net/ethernet/freescale/enetc/enetc_pf.c | 9 +++++---- 1 file changed, 5 insertions(+), 4 deletions(-)