[dpdk-dev] [PATCH] net/af_xdp: do not use fixed size storage for pointer

[Loftus, Ciara]

> 
> 'uint64_t' is used to hold the pointer, for 32-bits build this
> assumption is wrong and giving following build error:
> 
> rte_eth_af_xdp.c: In function ‘xdp_umem_configure’:
> rte_eth_af_xdp.c:970:15:
>     error: cast to pointer from integer of different size
>            [-Werror=int-to-pointer-cast]
>   970 |   base_addr = (void *)get_base_addr(mb_pool, &align);
>       |               ^
> 
> Replacing the 'uint64_t' return type of the 'get_base_addr()' to the
> 'uintptr_t'.
> Although not sure if the overall logic supports the 32-bits, using
> 'uintptr_t' should be safe both for 64/32 bits.
> 
> Fixes: d8a210774e1d ("net/af_xdp: support unaligned umem chunks")
> Cc: stable at dpdk.org
> 
> Signed-off-by: Ferruh Yigit <ferruh.yigit at intel.com>
> 
> ---
> 
> Hi Ciara,
> 
> I am not sure if 32-bit is supported for the af_xdp, but even not does
> this change make sense for the 64-bits?

Hi Ferruh,

LGTM. I've tested it for 64bit and all looks good to me.

Tested-by: Ciara Loftus <ciara.loftus at intel.com>

I've been looking into 32-bit compatibility and will submit a patch for at least the docs when I've verified what works.

Thanks,
Ciara

> ---
>  drivers/net/af_xdp/rte_eth_af_xdp.c | 6 +++---
>  1 file changed, 3 insertions(+), 3 deletions(-)
> 
> diff --git a/drivers/net/af_xdp/rte_eth_af_xdp.c
> b/drivers/net/af_xdp/rte_eth_af_xdp.c
> index 4076ff797c..2c7892bd7e 100644
> --- a/drivers/net/af_xdp/rte_eth_af_xdp.c
> +++ b/drivers/net/af_xdp/rte_eth_af_xdp.c
> @@ -910,13 +910,13 @@ eth_link_update(struct rte_eth_dev *dev
> __rte_unused,
>  }
> 
>  #if defined(XDP_UMEM_UNALIGNED_CHUNK_FLAG)
> -static inline uint64_t get_base_addr(struct rte_mempool *mp, uint64_t
> *align)
> +static inline uintptr_t get_base_addr(struct rte_mempool *mp, uint64_t
> *align)
>  {
>  	struct rte_mempool_memhdr *memhdr;
> -	uint64_t memhdr_addr, aligned_addr;
> +	uintptr_t memhdr_addr, aligned_addr;
> 
>  	memhdr = STAILQ_FIRST(&mp->mem_list);
> -	memhdr_addr = (uint64_t)memhdr->addr;
> +	memhdr_addr = (uintptr_t)memhdr->addr;
>  	aligned_addr = memhdr_addr & ~(getpagesize() - 1);
>  	*align = memhdr_addr - aligned_addr;
> 
> --
> 2.26.2