[PATCH] drivers: net: fsl_enetc: Pass on primary MAC address to Linux

[Alexandru Marginean]

On 12/10/2019 3:54 PM, Vladimir Oltean wrote:
> Hi Alex,
> 
> On Tue, 10 Dec 2019 at 16:21, Alex Marginean
> <alexandru.marginean at nxp.com> wrote:
>>
>> Passes on the primary address used by u-boot to Linux.  The code does a DT
>> fix-up for ENETC PFs and sets the primary MAC address in IERB.  The address
>> in IERB is restored on ENETC PCI functions at FLR.
>>
>> Signed-off-by: Alex Marginean <alexandru.marginean at nxp.com>
>> ---
>>
>> The code is called fom ft_board_setup in board/freescale/ls1028a/ls1028a.c
>> mostly for consistency with other LS parts.  I'm open to suggestions though.
>>
>>   board/freescale/ls1028a/ls1028a.c |  4 ++
>>   drivers/net/fsl_enetc.c           | 65 ++++++++++++++++++++++++++++++-
>>   2 files changed, 68 insertions(+), 1 deletion(-)
>>
>> diff --git a/board/freescale/ls1028a/ls1028a.c b/board/freescale/ls1028a/ls1028a.c
>> index 3977ecf896..fac03f55e9 100644
>> --- a/board/freescale/ls1028a/ls1028a.c
>> +++ b/board/freescale/ls1028a/ls1028a.c
>> @@ -150,6 +150,10 @@ int ft_board_setup(void *blob, bd_t *bd)
>>
>>          fdt_fixup_icid(blob);
>>
>> +#ifdef CONFIG_FSL_ENETC
>> +       fdt_fixup_enetc_mac(blob);
>> +#endif
>> +
>>          return 0;
>>   }
>>   #endif
>> diff --git a/drivers/net/fsl_enetc.c b/drivers/net/fsl_enetc.c
>> index 02c1ee70d9..f8fe7d4d8d 100644
>> --- a/drivers/net/fsl_enetc.c
>> +++ b/drivers/net/fsl_enetc.c
>> @@ -14,6 +14,69 @@
>>
>>   #include "fsl_enetc.h"
>>
>> +#define ENETC_DRIVER_NAME      "enetc_eth"
>> +
>> +/*
>> + * sets the MAC address in IERB registers, this setting is persistent and
>> + * carried over to Linux.
>> + */
>> +static void enetc_set_ierb_primary_mac(struct udevice *dev, int devfn,
>> +                                      const u8 *enetaddr)
>> +{
>> +#ifdef CONFIG_ARCH_LS1028A
>> +/*
>> + * LS1028A is the only part with IERB at this time and there are plans to change
>> + * its structure, keep this LS1028A specific for now
>> + */
>> +#define IERB_BASE              0x1f0800000ULL
>> +#define IERB_PFMAC(pf, vf, n)  (IERB_BASE + 0x8000 + (pf) * 0x100 + (vf) * 8 \
>> +                                + (n) * 4)
>> +
>> +static int ierb_fn_to_pf[] = {0, 1, 2, -1, -1, -1, 3};
>> +
>> +       u16 lower = *(const u16 *)(enetaddr + 4);
>> +       u32 upper = *(const u32 *)enetaddr;
>> +
>> +       if (ierb_fn_to_pf[devfn] < 0)
>> +               return;
>> +
>> +       out_le32(IERB_PFMAC(ierb_fn_to_pf[devfn], 0, 0), upper);
>> +       out_le32(IERB_PFMAC(ierb_fn_to_pf[devfn], 0, 1), (u32)lower);
>> +#endif
>> +}
>> +
>> +/* sets up primary MAC addresses in DT/IERB */
>> +void fdt_fixup_enetc_mac(void *blob)
>> +{
>> +       struct pci_child_platdata *ppdata;
>> +       struct eth_pdata *pdata;
>> +       struct udevice *dev;
>> +       struct uclass *uc;
>> +       char path[256];
>> +       int offset;
>> +       int devfn;
>> +
>> +       uclass_get(UCLASS_ETH, &uc);
>> +       uclass_foreach_dev(dev, uc) {
>> +               if (!dev->driver || !dev->driver->name ||
>> +                   strcmp(dev->driver->name, ENETC_DRIVER_NAME))
>> +                       continue;
>> +
>> +               pdata = dev_get_platdata(dev);
>> +               ppdata = dev_get_parent_platdata(dev);
>> +               devfn = PCI_FUNC(ppdata->devfn);
>> +
>> +               enetc_set_ierb_primary_mac(dev, devfn, pdata->enetaddr);
>> +
>> +               snprintf(path, 256, "/soc/pcie at 1f0000000/ethernet@%x,%x",
>> +                        PCI_DEV(ppdata->devfn), PCI_FUNC(ppdata->devfn));
>> +               offset = fdt_path_offset(blob, path);
>> +               if (offset < 0)
>> +                       continue;
>> +               fdt_setprop(blob, offset, "mac-address", pdata->enetaddr, 6);
> 
> The Linux Documentation/devicetree/bindings/net/ethernet.txt says:
> 
> - local-mac-address: array of 6 bytes, specifies the MAC address that was
>    assigned to the network device;
> - mac-address: array of 6 bytes, specifies the MAC address that was last used by
>    the boot program; should be used in cases where the MAC address assigned to
>    the device by the boot program is different from the "local-mac-address"
>    property;
> 
> I'm not sure which property should be used here, but I think local-mac-address.


U-Boot does use (well, if needed) that address, if that is of any 
importance.
of_get_mac_address in Linux has this comment:
/**
  * Search the device tree for the best MAC address to use. 
'mac-address' is
  * checked first, because that is supposed to contain to "most recent" MAC
  * address. If that isn't set, then 'local-mac-address' is checked next,
  * because that is the default address. If that isn't set, then the 
obsolete
  * 'address' is checked, just in case we're using an old device tree. 
If any
  * of the above isn't set, then try to get MAC address from nvmem cell 
named
  * 'mac-address'.


I think mac-address is fine, we can leave local-mac-address to be used 
with some default in Linux DT, in case mac-address is missing.
I don't have a strong opinion either way though.

Thanks!
Alex

> 
> 
>> +       }
>> +}
>> +
>>   /*
>>    * Bind the device:
>>    * - set a more explicit name on the interface
>> @@ -551,7 +614,7 @@ static const struct eth_ops enetc_ops = {
>>   };
>>
>>   U_BOOT_DRIVER(eth_enetc) = {
>> -       .name   = "enetc_eth",
>> +       .name   = ENETC_DRIVER_NAME,
>>          .id     = UCLASS_ETH,
>>          .bind   = enetc_bind,
>>          .probe  = enetc_probe,
>> --
>> 2.17.1
>>
> 
> Thanks,
> -Vladimir
>