Re: [PATCH net] octeontx2-af: Initialize bitmap arrays.

[Brett Creeley <bcreeley@amd.com>]

On 1/22/2024 9:12 PM, Ratheesh Kannoth wrote:
> Caution: This message originated from an External Source. Use proper caution when opening attachments, clicking links, or responding.
> 
> 
> kmalloc_array() does not initializes memory to zero.
> This causes issues with bitmap. Use devm_kcalloc()
> to fix the issue.
> 

Is there any reason to not use:

bitmap_zalloc() and bitmap_free()?

> Fixes: dd7842878633 ("octeontx2-af: Add new devlink param to configure maximum usable NIX block LFs")
> Signed-off-by: Ratheesh Kannoth <rkannoth@marvell.com>
> ---
>   .../ethernet/marvell/octeontx2/af/rvu_npc.c   | 55 ++++++++++---------
>   1 file changed, 28 insertions(+), 27 deletions(-)
> 
> diff --git a/drivers/net/ethernet/marvell/octeontx2/af/rvu_npc.c b/drivers/net/ethernet/marvell/octeontx2/af/rvu_npc.c
> index 167145bdcb75..7539e6f0290a 100644
> --- a/drivers/net/ethernet/marvell/octeontx2/af/rvu_npc.c
> +++ b/drivers/net/ethernet/marvell/octeontx2/af/rvu_npc.c
> @@ -1850,13 +1850,13 @@ void npc_mcam_rsrcs_deinit(struct rvu *rvu)
>   {
>          struct npc_mcam *mcam = &rvu->hw->mcam;
> 
> -       kfree(mcam->bmap);
> -       kfree(mcam->bmap_reverse);
> -       kfree(mcam->entry2pfvf_map);
> -       kfree(mcam->cntr2pfvf_map);
> -       kfree(mcam->entry2cntr_map);
> -       kfree(mcam->cntr_refcnt);
> -       kfree(mcam->entry2target_pffunc);
> +       devm_kfree(rvu->dev, mcam->bmap);
> +       devm_kfree(rvu->dev, mcam->bmap_reverse);
> +       devm_kfree(rvu->dev, mcam->entry2pfvf_map);
> +       devm_kfree(rvu->dev, mcam->cntr2pfvf_map);
> +       devm_kfree(rvu->dev, mcam->entry2cntr_map);
> +       devm_kfree(rvu->dev, mcam->cntr_refcnt);
> +       devm_kfree(rvu->dev, mcam->entry2target_pffunc);
>          kfree(mcam->counters.bmap);
>   }
> 
> @@ -1904,21 +1904,22 @@ int npc_mcam_rsrcs_init(struct rvu *rvu, int blkaddr)
>          mcam->pf_offset = mcam->nixlf_offset + nixlf_count;
> 
>          /* Allocate bitmaps for managing MCAM entries */
> -       mcam->bmap = kmalloc_array(BITS_TO_LONGS(mcam->bmap_entries),
> -                                  sizeof(long), GFP_KERNEL);
> +       mcam->bmap = devm_kcalloc(rvu->dev, BITS_TO_LONGS(mcam->bmap_entries),
> +                                 sizeof(long), GFP_KERNEL);

This is pretty much bitmap_zalloc(), except with devm. As Simon is 
asking, is devm really necessary? If not bitmap_zalloc() and 
bitmap_free() seem to fit your use well if I'm not mistaken.

Thanks,

Brett
>          if (!mcam->bmap)
>                  return -ENOMEM;
> 
> -       mcam->bmap_reverse = kmalloc_array(BITS_TO_LONGS(mcam->bmap_entries),
> -                                          sizeof(long), GFP_KERNEL);
> +       mcam->bmap_reverse = devm_kcalloc(rvu->dev,
> +                                         BITS_TO_LONGS(mcam->bmap_entries),
> +                                         sizeof(long), GFP_KERNEL);
>          if (!mcam->bmap_reverse)
>                  goto free_bmap;
> 
>          mcam->bmap_fcnt = mcam->bmap_entries;
> 
>          /* Alloc memory for saving entry to RVU PFFUNC allocation mapping */
> -       mcam->entry2pfvf_map = kmalloc_array(mcam->bmap_entries,
> -                                            sizeof(u16), GFP_KERNEL);
> +       mcam->entry2pfvf_map = devm_kcalloc(rvu->dev, mcam->bmap_entries,
> +                                           sizeof(u16), GFP_KERNEL);
>          if (!mcam->entry2pfvf_map)
>                  goto free_bmap_reverse;
> 
> @@ -1941,27 +1942,27 @@ int npc_mcam_rsrcs_init(struct rvu *rvu, int blkaddr)
>          if (err)
>                  goto free_entry_map;
> 
> -       mcam->cntr2pfvf_map = kmalloc_array(mcam->counters.max,
> -                                           sizeof(u16), GFP_KERNEL);
> +       mcam->cntr2pfvf_map = devm_kcalloc(rvu->dev, mcam->counters.max,
> +                                          sizeof(u16), GFP_KERNEL);
>          if (!mcam->cntr2pfvf_map)
>                  goto free_cntr_bmap;
> 
>          /* Alloc memory for MCAM entry to counter mapping and for tracking
>           * counter's reference count.
>           */
> -       mcam->entry2cntr_map = kmalloc_array(mcam->bmap_entries,
> -                                            sizeof(u16), GFP_KERNEL);
> +       mcam->entry2cntr_map = devm_kcalloc(rvu->dev, mcam->bmap_entries,
> +                                           sizeof(u16), GFP_KERNEL);
>          if (!mcam->entry2cntr_map)
>                  goto free_cntr_map;
> 
> -       mcam->cntr_refcnt = kmalloc_array(mcam->counters.max,
> -                                         sizeof(u16), GFP_KERNEL);
> +       mcam->cntr_refcnt = devm_kcalloc(rvu->dev, mcam->counters.max,
> +                                        sizeof(u16), GFP_KERNEL);
>          if (!mcam->cntr_refcnt)
>                  goto free_entry_cntr_map;
> 
>          /* Alloc memory for saving target device of mcam rule */
> -       mcam->entry2target_pffunc = kmalloc_array(mcam->total_entries,
> -                                                 sizeof(u16), GFP_KERNEL);
> +       mcam->entry2target_pffunc = devm_kcalloc(rvu->dev, mcam->total_entries,
> +                                                sizeof(u16), GFP_KERNEL);
>          if (!mcam->entry2target_pffunc)
>                  goto free_cntr_refcnt;
> 
> @@ -1978,19 +1979,19 @@ int npc_mcam_rsrcs_init(struct rvu *rvu, int blkaddr)
>          return 0;
> 
>   free_cntr_refcnt:
> -       kfree(mcam->cntr_refcnt);
> +       devm_kfree(rvu->dev, mcam->cntr_refcnt);
>   free_entry_cntr_map:
> -       kfree(mcam->entry2cntr_map);
> +       devm_kfree(rvu->dev, mcam->entry2cntr_map);
>   free_cntr_map:
> -       kfree(mcam->cntr2pfvf_map);
> +       devm_kfree(rvu->dev, mcam->cntr2pfvf_map);
>   free_cntr_bmap:
>          kfree(mcam->counters.bmap);
>   free_entry_map:
> -       kfree(mcam->entry2pfvf_map);
> +       devm_kfree(rvu->dev, mcam->entry2pfvf_map);
>   free_bmap_reverse:
> -       kfree(mcam->bmap_reverse);
> +       devm_kfree(rvu->dev, mcam->bmap_reverse);
>   free_bmap:
> -       kfree(mcam->bmap);
> +       devm_kfree(rvu->dev, mcam->bmap);
> 
>          return -ENOMEM;
>   }
> --
> 2.25.1
> 
>