Subject: Re: [PATCH RFC] brcmfmac: support deleting MBSS AP interfaces

From: Arend van Spriel <[email-masked]>
Date: Wed, 1 Jun 2016 21:00:40 +0200

On 01-06-16 16:36, Rafał Miłecki wrote:
> We already support adding extra (AP) interfaces so it also makes an
> obvious sense to allow deleting them.
> 
> Adding a new interface is implemented by sending request to firmware for
> creating a new BSS and waiting for a proper event. Ideally deleting
> interface should be handled in a similar way. There should be a request
> to firmware for deleting BSS and firmware should respond with an event.
> 
> Unfortunately it doesn't seem to work with recent firmwares. They never
> seem to delete BSS and never send BRCMF_E_IF_DEL. As a workaround this
> patch deletes Linux interface while keeping a track of BSSes present in
> a firmware. If there is request for adding a new interface this code is
> capable of reusing existing BSS-es.

It is not so much an issue of recent firmware. Actually, on recent
firmware 7.x.y.z and higher there are other command to create *and*
delete additional interfaces. On the other hand we aim to support a
large number of devices going back to bcm4329 so we have to come up with
a scheme to use the new commands or fallback to old api. Let's hope we
can reuse much of this effort you put in.

> Signed-off-by: Rafał Miłecki <[email-masked]>
> ---
>  .../broadcom/brcm80211/brcmfmac/cfg80211.c         | 84 +++++++++++++++-------
>  .../wireless/broadcom/brcm80211/brcmfmac/core.c    |  6 +-
>  .../wireless/broadcom/brcm80211/brcmfmac/core.h    |  4 +-
>  .../wireless/broadcom/brcm80211/brcmfmac/fweh.c    |  4 +-
>  4 files changed, 71 insertions(+), 27 deletions(-)
> 
> diff --git a/drivers/net/wireless/broadcom/brcm80211/brcmfmac/cfg80211.c b/drivers/net/wireless/broadcom/brcm80211/brcmfmac/cfg80211.c
> index d23b95e..ce35ada 100644
> --- a/drivers/net/wireless/broadcom/brcm80211/brcmfmac/cfg80211.c
> +++ b/drivers/net/wireless/broadcom/brcm80211/brcmfmac/cfg80211.c
> @@ -35,6 +35,7 @@
>  #include "cfg80211.h"
>  #include "feature.h"
>  #include "fwil.h"
> +#include "fwsignal.h"
>  #include "proto.h"
>  #include "vendor.h"
>  #include "bus.h"
> @@ -556,10 +557,10 @@ static int brcmf_get_first_free_bsscfgidx(struct brcmf_pub *drvr)
>  	return -ENOMEM;
>  }
>  
> -static int brcmf_cfg80211_request_ap_if(struct brcmf_if *ifp)
> +static int brcmf_cfg80211_request_ap_if(struct brcmf_cfg80211_info *cfg, int bsscfgidx)
>  {
> +	struct brcmf_if *ifp = netdev_priv(cfg_to_ndev(cfg));
>  	struct brcmf_mbss_ssid_le mbss_ssid_le;
> -	int bsscfgidx;
>  	int err;
>  
>  	memset(&mbss_ssid_le, 0, sizeof(mbss_ssid_le));
> @@ -594,6 +595,7 @@ struct wireless_dev *brcmf_ap_add_vif(struct wiphy *wiphy, const char *name,
>  	struct brcmf_cfg80211_info *cfg = wiphy_to_cfg(wiphy);
>  	struct brcmf_if *ifp = netdev_priv(cfg_to_ndev(cfg));
>  	struct brcmf_cfg80211_vif *vif;
> +	int bsscfgidx;
>  	int err;
>  
>  	if (brcmf_cfg80211_vif_event_armed(cfg))
> @@ -605,30 +607,49 @@ struct wireless_dev *brcmf_ap_add_vif(struct wiphy *wiphy, const char *name,
>  	if (IS_ERR(vif))
>  		return (struct wireless_dev *)vif;
>  
> -	brcmf_cfg80211_arm_vif_event(cfg, vif);
> +	bsscfgidx = brcmf_get_first_free_bsscfgidx(cfg->pub);
> +	brcmf_err("bsscfgidx:%d cfg->pub->bss2if[bsscfgidx]:%d\n", bsscfgidx, cfg->pub->bss2if[bsscfgidx]);

Looks like debugging code. If you want to keep it, make it
brcmf_dbg(INFO, ...).

> +	if (cfg->pub->bss2if[bsscfgidx] != BRCMF_IDX_INVALID) {
> +		ifp = brcmf_add_if(cfg->pub, bsscfgidx, cfg->pub->bss2if[bsscfgidx], false, "wlan%d", params->macaddr);
> +		if (IS_ERR(ifp)) {
> +			err = PTR_ERR(ifp);
> +			goto fail;
> +		}
> +		brcmf_fws_add_interface(ifp);
>  
> -	err = brcmf_cfg80211_request_ap_if(ifp);
> -	if (err) {
> -		brcmf_cfg80211_arm_vif_event(cfg, NULL);
> -		goto fail;
> -	}
> +		ifp->vif = vif;
> +		vif->ifp = ifp;
> +		if (ifp->ndev) {
> +			vif->wdev.netdev = ifp->ndev;
> +			ifp->ndev->ieee80211_ptr = &vif->wdev;
> +			SET_NETDEV_DEV(ifp->ndev, wiphy_dev(cfg->wiphy));
> +		}
> +	} else {
> +		brcmf_cfg80211_arm_vif_event(cfg, vif);
>  
> -	/* wait for firmware event */
> -	err = brcmf_cfg80211_wait_vif_event(cfg, BRCMF_E_IF_ADD,
> -					    BRCMF_VIF_EVENT_TIMEOUT);
> -	brcmf_cfg80211_arm_vif_event(cfg, NULL);
> -	if (!err) {
> -		brcmf_err("timeout occurred\n");
> -		err = -EIO;
> -		goto fail;
> -	}
> +		err = brcmf_cfg80211_request_ap_if(cfg, bsscfgidx);
> +		if (err) {
> +			brcmf_cfg80211_arm_vif_event(cfg, NULL);
> +			goto fail;
> +		}
>  
> -	/* interface created in firmware */
> -	ifp = vif->ifp;
> -	if (!ifp) {
> -		brcmf_err("no if pointer provided\n");
> -		err = -ENOENT;
> -		goto fail;
> +		/* wait for firmware event */
> +		err = brcmf_cfg80211_wait_vif_event(cfg, BRCMF_E_IF_ADD,
> +						BRCMF_VIF_EVENT_TIMEOUT);
> +		brcmf_cfg80211_arm_vif_event(cfg, NULL);
> +		if (!err) {
> +			brcmf_err("timeout occurred\n");
> +			err = -EIO;
> +			goto fail;
> +		}
> +
> +		/* interface created in firmware */
> +		ifp = vif->ifp;
> +		if (!ifp) {
> +			brcmf_err("no if pointer provided\n");
> +			err = -ENOENT;
> +			goto fail;
> +		}
>  	}
>  
>  	strncpy(ifp->ndev->name, name, sizeof(ifp->ndev->name) - 1);
> @@ -781,12 +802,26 @@ s32 brcmf_notify_escan_complete(struct brcmf_cfg80211_info *cfg,
>  	return err;
>  }
>  
> +static int brcmf_cfg80211_del_ap_iface(struct wiphy *wiphy,
> +				       struct wireless_dev *wdev)
> +{
> +	struct net_device *ndev = wdev->netdev;
> +	struct brcmf_if *ifp = netdev_priv(ndev);
> +
> +	brcmf_remove_interface(ifp);
> +
> +	return 0;
> +}
> +
>  static
>  int brcmf_cfg80211_del_iface(struct wiphy *wiphy, struct wireless_dev *wdev)
>  {
>  	struct brcmf_cfg80211_info *cfg = wiphy_priv(wiphy);
>  	struct net_device *ndev = wdev->netdev;
>  
> +	if (ndev == cfg_to_ndev(cfg))
> +		return -ENOTSUPP;
> +
>  	/* vif event pending in firmware */
>  	if (brcmf_cfg80211_vif_event_armed(cfg))
>  		return -EBUSY;
> @@ -803,12 +838,13 @@ int brcmf_cfg80211_del_iface(struct wiphy *wiphy, struct wireless_dev *wdev)
>  	switch (wdev->iftype) {
>  	case NL80211_IFTYPE_ADHOC:
>  	case NL80211_IFTYPE_STATION:
> -	case NL80211_IFTYPE_AP:
>  	case NL80211_IFTYPE_AP_VLAN:
>  	case NL80211_IFTYPE_WDS:
>  	case NL80211_IFTYPE_MONITOR:
>  	case NL80211_IFTYPE_MESH_POINT:
>  		return -EOPNOTSUPP;
> +	case NL80211_IFTYPE_AP:
> +		return brcmf_cfg80211_del_ap_iface(wiphy, wdev);
>  	case NL80211_IFTYPE_P2P_CLIENT:
>  	case NL80211_IFTYPE_P2P_GO:
>  	case NL80211_IFTYPE_P2P_DEVICE:
> diff --git a/drivers/net/wireless/broadcom/brcm80211/brcmfmac/core.c b/drivers/net/wireless/broadcom/brcm80211/brcmfmac/core.c
> index 6a76480..1208c21 100644
> --- a/drivers/net/wireless/broadcom/brcm80211/brcmfmac/core.c
> +++ b/drivers/net/wireless/broadcom/brcm80211/brcmfmac/core.c
> @@ -634,7 +634,7 @@ fail:
>  }
>  
>  struct brcmf_if *brcmf_add_if(struct brcmf_pub *drvr, s32 bsscfgidx, s32 ifidx,
> -			      bool is_p2pdev, char *name, u8 *mac_addr)
> +			      bool is_p2pdev, const char *name, u8 *mac_addr)

Seems like an unrelated change.

>  {
>  	struct brcmf_if *ifp;
>  	struct net_device *ndev;
> @@ -680,6 +680,8 @@ struct brcmf_if *brcmf_add_if(struct brcmf_pub *drvr, s32 bsscfgidx, s32 ifidx,
>  		/* store mapping ifidx to bsscfgidx */
>  		if (drvr->if2bss[ifidx] == BRCMF_BSSIDX_INVALID)
>  			drvr->if2bss[ifidx] = bsscfgidx;
> +		if (drvr->bss2if[bsscfgidx] == BRCMF_IDX_INVALID)
> +			drvr->bss2if[bsscfgidx] = ifidx;
>  	}
>  
>  	ifp->drvr = drvr;
> @@ -910,6 +912,8 @@ int brcmf_attach(struct device *dev, struct brcmf_mp_device *settings)
>  
>  	for (i = 0; i < ARRAY_SIZE(drvr->if2bss); i++)
>  		drvr->if2bss[i] = BRCMF_BSSIDX_INVALID;
> +	for (i = 0; i < ARRAY_SIZE(drvr->bss2if); i++)
> +		drvr->bss2if[i] = BRCMF_IDX_INVALID;

both have size BRCMF_MAX_IFS so might stick with one loop as it is
unlikely the size of these two arrays will ever differ.

>  	mutex_init(&drvr->proto_block);
>  
> diff --git a/drivers/net/wireless/broadcom/brcm80211/brcmfmac/core.h b/drivers/net/wireless/broadcom/brcm80211/brcmfmac/core.h
> index 2a075c5..edd322a 100644
> --- a/drivers/net/wireless/broadcom/brcm80211/brcmfmac/core.h
> +++ b/drivers/net/wireless/broadcom/brcm80211/brcmfmac/core.h
> @@ -29,6 +29,7 @@
>  
>  /* For supporting multiple interfaces */
>  #define BRCMF_MAX_IFS	16
> +#define BRCMF_IDX_INVALID	-1
>  
>  /* Small, medium and maximum buffer size for dcmd
>   */
> @@ -125,6 +126,7 @@ struct brcmf_pub {
>  
>  	struct brcmf_if *iflist[BRCMF_MAX_IFS];
>  	s32 if2bss[BRCMF_MAX_IFS];
> +	s32 bss2if[BRCMF_MAX_IFS];
>  
>  	struct mutex proto_block;
>  	unsigned char proto_buf[BRCMF_DCMD_MAXLEN];
> @@ -215,7 +217,7 @@ char *brcmf_ifname(struct brcmf_if *ifp);
>  struct brcmf_if *brcmf_get_ifp(struct brcmf_pub *drvr, int ifidx);
>  int brcmf_net_attach(struct brcmf_if *ifp, bool rtnl_locked);
>  struct brcmf_if *brcmf_add_if(struct brcmf_pub *drvr, s32 bsscfgidx, s32 ifidx,
> -			      bool is_p2pdev, char *name, u8 *mac_addr);
> +			      bool is_p2pdev, const char *name, u8 *mac_addr);
>  void brcmf_remove_interface(struct brcmf_if *ifp);
>  void brcmf_txflowblock_if(struct brcmf_if *ifp,
>  			  enum brcmf_netif_stop_reason reason, bool state);
> diff --git a/drivers/net/wireless/broadcom/brcm80211/brcmfmac/fweh.c b/drivers/net/wireless/broadcom/brcm80211/brcmfmac/fweh.c
> index b390561..5bde857 100644
> --- a/drivers/net/wireless/broadcom/brcm80211/brcmfmac/fweh.c
> +++ b/drivers/net/wireless/broadcom/brcm80211/brcmfmac/fweh.c
> @@ -182,8 +182,10 @@ static void brcmf_fweh_handle_if_event(struct brcmf_pub *drvr,
>  
>  	err = brcmf_fweh_call_event_handler(ifp, emsg->event_code, emsg, data);
>  
> -	if (ifp && ifevent->action == BRCMF_E_IF_DEL)
> +	if (ifp && ifevent->action == BRCMF_E_IF_DEL) {
>  		brcmf_remove_interface(ifp);
> +		drvr->bss2if[ifp->bsscfgidx] = BRCMF_IDX_INVALID;

Why not do this in brcmf_remove_interface(). Seems more clean to me.

Regards,
Arend