On 15/02/2019 02:15, Sasha Levin wrote:
> From: Edward Cree <ec...@solarflare.com>
> 
> [ Upstream commit 3366463513f544c12c6b88c13da4462ee9e7a1a1 ]
> 
> Use a bitmap to keep track of which partition types we've already seen;
>  for duplicates, return -EEXIST from efx_ef10_mtd_probe_partition() and
>  thus skip adding that partition.
> Duplicate partitions occur because of the A/B backup scheme used by newer
>  sfc NICs.  Prior to this patch they cause sysfs_warn_dup errors because
>  they have the same name, causing us not to expose any MTDs at all.
> 
> Signed-off-by: Edward Cree <ec...@solarflare.com>
> Signed-off-by: David S. Miller <da...@davemloft.net>
> Signed-off-by: Sasha Levin <sas...@kernel.org>

I don't think this particularly needs to go to stable, but if it does it
should be accompanied by:
  c65285428b6e ("sfc: initialise found bitmap in efx_ef10_mtd_probe")

Bert.

> ---
>  drivers/net/ethernet/sfc/ef10.c | 29 +++++++++++++++++++++--------
>  1 file changed, 21 insertions(+), 8 deletions(-)
> 
> diff --git a/drivers/net/ethernet/sfc/ef10.c b/drivers/net/ethernet/sfc/ef10.c
> index 010009d64017..84a17b41313c 100644
> --- a/drivers/net/ethernet/sfc/ef10.c
> +++ b/drivers/net/ethernet/sfc/ef10.c
> @@ -3407,22 +3407,25 @@ static const struct efx_ef10_nvram_type_info 
> efx_ef10_nvram_types[] = {
>       { NVRAM_PARTITION_TYPE_LICENSE,            0,    0, "sfc_license" },
>       { NVRAM_PARTITION_TYPE_PHY_MIN,            0xff, 0, "sfc_phy_fw" },
>  };
> +#define EF10_NVRAM_PARTITION_COUNT   ARRAY_SIZE(efx_ef10_nvram_types)
>  
>  static int efx_ef10_mtd_probe_partition(struct efx_nic *efx,
>                                       struct efx_mcdi_mtd_partition *part,
> -                                     unsigned int type)
> +                                     unsigned int type,
> +                                     unsigned long *found)
>  {
>       MCDI_DECLARE_BUF(inbuf, MC_CMD_NVRAM_METADATA_IN_LEN);
>       MCDI_DECLARE_BUF(outbuf, MC_CMD_NVRAM_METADATA_OUT_LENMAX);
>       const struct efx_ef10_nvram_type_info *info;
>       size_t size, erase_size, outlen;
> +     int type_idx = 0;
>       bool protected;
>       int rc;
>  
> -     for (info = efx_ef10_nvram_types; ; info++) {
> -             if (info ==
> -                 efx_ef10_nvram_types + ARRAY_SIZE(efx_ef10_nvram_types))
> +     for (type_idx = 0; ; type_idx++) {
> +             if (type_idx == EF10_NVRAM_PARTITION_COUNT)
>                       return -ENODEV;
> +             info = efx_ef10_nvram_types + type_idx;
>               if ((type & ~info->type_mask) == info->type)
>                       break;
>       }
> @@ -3435,6 +3438,13 @@ static int efx_ef10_mtd_probe_partition(struct efx_nic 
> *efx,
>       if (protected)
>               return -ENODEV; /* hide it */
>  
> +     /* If we've already exposed a partition of this type, hide this
> +      * duplicate.  All operations on MTDs are keyed by the type anyway,
> +      * so we can't act on the duplicate.
> +      */
> +     if (__test_and_set_bit(type_idx, found))
> +             return -EEXIST;
> +
>       part->nvram_type = type;
>  
>       MCDI_SET_DWORD(inbuf, NVRAM_METADATA_IN_TYPE, type);
> @@ -3463,6 +3473,7 @@ static int efx_ef10_mtd_probe_partition(struct efx_nic 
> *efx,
>  static int efx_ef10_mtd_probe(struct efx_nic *efx)
>  {
>       MCDI_DECLARE_BUF(outbuf, MC_CMD_NVRAM_PARTITIONS_OUT_LENMAX);
> +     DECLARE_BITMAP(found, EF10_NVRAM_PARTITION_COUNT);
>       struct efx_mcdi_mtd_partition *parts;
>       size_t outlen, n_parts_total, i, n_parts;
>       unsigned int type;
> @@ -3491,11 +3502,13 @@ static int efx_ef10_mtd_probe(struct efx_nic *efx)
>       for (i = 0; i < n_parts_total; i++) {
>               type = MCDI_ARRAY_DWORD(outbuf, NVRAM_PARTITIONS_OUT_TYPE_ID,
>                                       i);
> -             rc = efx_ef10_mtd_probe_partition(efx, &parts[n_parts], type);
> -             if (rc == 0)
> -                     n_parts++;
> -             else if (rc != -ENODEV)
> +             rc = efx_ef10_mtd_probe_partition(efx, &parts[n_parts], type,
> +                                               found);
> +             if (rc == -EEXIST || rc == -ENODEV)
> +                     continue;
> +             if (rc)
>                       goto fail;
> +             n_parts++;
>       }
>  
>       rc = efx_mtd_add(efx, &parts[0].common, n_parts, sizeof(*parts));
> 

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