Re: [PATCH wireless-next] wifi: brcm80211: change current_bss to a FAM

[Arend van Spriel <arend.vanspriel@broadcom.com>]

On 01/04/2026 01:32, Rosen Penev wrote:
> Change to a single allocation with kzalloc_flex and remove some
> boilerplate.
> 
> Done as a FAM instead of value to keep -> usage in codebase.

I get it and it looks a bit like a trick, but....

> Signed-off-by: Rosen Penev <rosenp@gmail.com>
> ---
>   .../broadcom/brcm80211/brcmsmac/main.c        | 32 ++-----------------
>   .../broadcom/brcm80211/brcmsmac/main.h        |  2 +-
>   2 files changed, 3 insertions(+), 31 deletions(-)
> 
> diff --git a/drivers/net/wireless/broadcom/brcm80211/brcmsmac/main.c b/drivers/net/wireless/broadcom/brcm80211/brcmsmac/main.c
> index c7eaf160e1fa..4f57d64b1dd3 100644
> --- a/drivers/net/wireless/broadcom/brcm80211/brcmsmac/main.c
> +++ b/drivers/net/wireless/broadcom/brcm80211/brcmsmac/main.c
> @@ -418,21 +418,12 @@ static int brcms_chspec_bw(u16 chanspec)
>   	return BRCMS_10_MHZ;
>   }
> 
> -static void brcms_c_bsscfg_mfree(struct brcms_bss_cfg *cfg)
> -{
> -	if (cfg == NULL)
> -		return;
> -
> -	kfree(cfg->current_bss);
> -	kfree(cfg);
> -}
> -

... it does clearly give some code reduction.

>   static void brcms_c_detach_mfree(struct brcms_c_info *wlc)
>   {
>   	if (wlc == NULL)
>   		return;
> 
> -	brcms_c_bsscfg_mfree(wlc->bsscfg);
> +	kfree(wlc->bsscfg);
>   	kfree(wlc->pub);
>   	kfree(wlc->modulecb);
>   	kfree(wlc->default_bss);

[...]

> @@ -527,7 +499,7 @@ brcms_c_attach_malloc(uint unit, uint *err, uint devid)
>   		goto fail;
>   	}
> 
> -	wlc->bsscfg = brcms_c_bsscfg_malloc(unit);
> +	wlc->bsscfg = kzalloc_flex(*wlc->bsscfg, current_bss, 1, GFP_ATOMIC);
>   	if (wlc->bsscfg == NULL) {
>   		*err = 1011;
>   		goto fail;
> diff --git a/drivers/net/wireless/broadcom/brcm80211/brcmsmac/main.h b/drivers/net/wireless/broadcom/brcm80211/brcmsmac/main.h
> index b7ca0d9891c4..e9cbb95a5a17 100644
> --- a/drivers/net/wireless/broadcom/brcm80211/brcmsmac/main.h
> +++ b/drivers/net/wireless/broadcom/brcm80211/brcmsmac/main.h
> @@ -614,7 +614,7 @@ struct brcms_bss_cfg {
>   	u8 SSID_len;
>   	u8 SSID[IEEE80211_MAX_SSID_LEN];
>   	u8 BSSID[ETH_ALEN];
> -	struct brcms_bss_info *current_bss;
> +	struct brcms_bss_info current_bss[];

It does feel icky to use a flex array for 1:1 object relation. It seems 
the lifetime of both objects is exactly the same so I would consider 
using the value instead of FAM. It would give the same code reduction, 
but making the patch slightly larger.

main.c:	kfree(cfg->current_bss);
main.c:	cfg->current_bss = kzalloc_obj(*cfg->current_bss, GFP_ATOMIC);
main.c:	if (cfg->current_bss == NULL)
main.c:			wlc->bsscfg->current_bss->chanspec = chanspec;
main.c:		rs = &wlc->bsscfg->current_bss->rateset;
main.c:			mcsset_bss = wlc->bsscfg->current_bss;
main.c:		bi = wlc->bsscfg->current_bss->beacon_period << 10;

So it is used in just 4 places not counting the first 3 hits for obvious 
reasons. Not too much effort to use value here so please do that.

Regards,
Arend