Subject: Re: [PATCH net v3] octeontx2-af: Initialize maps.

From: Simon Horman <[email-masked]>
Date: Thu, 1 Feb 2024 10:31:19 +0100

On Wed, Jan 31, 2024 at 08:11:18AM +0530, Ratheesh Kannoth wrote:
> kmalloc_array() without __GFP_ZERO flag does not initialize
> memory to zero. This causes issues. Use __GFP_ZERO flag for maps and
> bitmap_zalloc() for bimaps.
> 
> Fixes: dd7842878633 ("octeontx2-af: Add new devlink param to configure maximum usable NIX block LFs")
> Signed-off-by: Ratheesh Kannoth <[email-masked]>
> ---
> 
> ChangeLogs:
> v2 -> v3: Used GFP_ZERO for normal map arrays
> v1 -> v2: Used bitmap_zalloc() API.
> v0 -> v1: Removed devm_kcalloc()._
> ---
>  .../ethernet/marvell/octeontx2/af/rvu_npc.c   | 26 ++++++++++---------
>  1 file changed, 14 insertions(+), 12 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..6a8f0efd96a5 100644
> --- a/drivers/net/ethernet/marvell/octeontx2/af/rvu_npc.c
> +++ b/drivers/net/ethernet/marvell/octeontx2/af/rvu_npc.c
> @@ -1850,8 +1850,8 @@ void npc_mcam_rsrcs_deinit(struct rvu *rvu)
>  {
>  	struct npc_mcam *mcam = &rvu->hw->mcam;
> 
> -	kfree(mcam->bmap);
> -	kfree(mcam->bmap_reverse);
> +	bitmap_free(mcam->bmap);
> +	bitmap_free(mcam->bmap_reverse);
>  	kfree(mcam->entry2pfvf_map);
>  	kfree(mcam->cntr2pfvf_map);
>  	kfree(mcam->entry2cntr_map);
> @@ -1904,13 +1904,11 @@ 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 = bitmap_zalloc(mcam->bmap_entries, GFP_KERNEL);
>  	if (!mcam->bmap)
>  		return -ENOMEM;
> 
> -	mcam->bmap_reverse = kmalloc_array(BITS_TO_LONGS(mcam->bmap_entries),
> -					   sizeof(long), GFP_KERNEL);
> +	mcam->bmap_reverse = bitmap_zalloc(mcam->bmap_entries, GFP_KERNEL);
>  	if (!mcam->bmap_reverse)
>  		goto free_bmap;
> 
> @@ -1918,7 +1916,8 @@ int npc_mcam_rsrcs_init(struct rvu *rvu, int blkaddr)
> 
>  	/* Alloc memory for saving entry to RVU PFFUNC allocation mapping */
>  	mcam->entry2pfvf_map = kmalloc_array(mcam->bmap_entries,
> -					     sizeof(u16), GFP_KERNEL);
> +					     sizeof(u16),
> +					     GFP_KERNEL | __GFP_ZERO);

Hi Ratheesh,

The use of bitmap_zalloc()/bitmap_free() looks good to me.
But for the kmalloc_array(..., GFP_KERNEL | __GFP_ZERO) cases
I think kcalloc() is the way to go.

>  	if (!mcam->entry2pfvf_map)
>  		goto free_bmap_reverse;
> 
> @@ -1942,7 +1941,8 @@ int npc_mcam_rsrcs_init(struct rvu *rvu, int blkaddr)
>  		goto free_entry_map;
> 
>  	mcam->cntr2pfvf_map = kmalloc_array(mcam->counters.max,
> -					    sizeof(u16), GFP_KERNEL);
> +					    sizeof(u16),
> +					    GFP_KERNEL | __GFP_ZERO);
>  	if (!mcam->cntr2pfvf_map)
>  		goto free_cntr_bmap;
> 
> @@ -1950,12 +1950,14 @@ int npc_mcam_rsrcs_init(struct rvu *rvu, int blkaddr)
>  	 * counter's reference count.
>  	 */
>  	mcam->entry2cntr_map = kmalloc_array(mcam->bmap_entries,
> -					     sizeof(u16), GFP_KERNEL);
> +					     sizeof(u16),
> +					     GFP_KERNEL | __GFP_ZERO);
>  	if (!mcam->entry2cntr_map)
>  		goto free_cntr_map;
> 
>  	mcam->cntr_refcnt = kmalloc_array(mcam->counters.max,
> -					  sizeof(u16), GFP_KERNEL);
> +					  sizeof(u16),
> +					  GFP_KERNEL | __GFP_ZERO);
>  	if (!mcam->cntr_refcnt)
>  		goto free_entry_cntr_map;
> 
> @@ -1988,9 +1990,9 @@ int npc_mcam_rsrcs_init(struct rvu *rvu, int blkaddr)
>  free_entry_map:
>  	kfree(mcam->entry2pfvf_map);
>  free_bmap_reverse:
> -	kfree(mcam->bmap_reverse);
> +	bitmap_free(mcam->bmap_reverse);
>  free_bmap:
> -	kfree(mcam->bmap);
> +	bitmap_free(mcam->bmap);
> 
>  	return -ENOMEM;
>  }
> --
> 2.25.1
> 

-- 
pw-bot: changes-requested