brcmfmac: add mutex to protect pno requests

The request references kept in pno are accessed in user-space context
and in firmware event handler context. As such we need to protect it
with a lock. As both context allow sleep a mutex seems appropriate.

Reviewed-by: Hante Meuleman <hante.meuleman@broadcom.com>
Reviewed-by: Pieter-Paul Giesberts <pieter-paul.giesberts@broadcom.com>
Reviewed-by: Franky Lin <franky.lin@broadcom.com>
Signed-off-by: Arend van Spriel <arend.vanspriel@broadcom.com>
Signed-off-by: Kalle Valo <kvalo@codeaurora.org>

diff --git a/drivers/net/wireless/broadcom/brcm80211/brcmfmac/pno.c b/drivers/net/wireless/broadcom/brcm80211/brcmfmac/pno.c
index a4207754075bc8077f7dabbe580bfad31837de4d..e488bebd01e1ab6fa7e06ede3994e5d8d39e0d70 100644 (file)
--- a/drivers/net/wireless/broadcom/brcm80211/brcmfmac/pno.c
+++ b/drivers/net/wireless/broadcom/brcm80211/brcmfmac/pno.c
@@ -43,6 +43,7 @@
 struct brcmf_pno_info {
        int n_reqs;
        struct cfg80211_sched_scan_request *reqs[BRCMF_PNO_MAX_BUCKETS];
+       struct mutex req_lock;
 };
 
 #define ifp_to_pno(_ifp)       ((_ifp)->drvr->config->pno)
@@ -55,13 +56,17 @@ static int brcmf_pno_store_request(struct brcmf_pno_info *pi,
                return -ENOSPC;
 
        brcmf_dbg(SCAN, "reqid=%llu\n", req->reqid);
+       mutex_lock(&pi->req_lock);
        pi->reqs[pi->n_reqs++] = req;
+       mutex_unlock(&pi->req_lock);
        return 0;
 }
 
 static int brcmf_pno_remove_request(struct brcmf_pno_info *pi, u64 reqid)
 {
-       int i;
+       int i, err = 0;
+
+       mutex_lock(&pi->req_lock);
 
        /* find request */
        for (i = 0; i < pi->n_reqs; i++) {
@@ -70,7 +75,8 @@ static int brcmf_pno_remove_request(struct brcmf_pno_info *pi, u64 reqid)
        }
        /* request not found */
        if (WARN(i == pi->n_reqs, "reqid not found\n")) {
-               return -ENOENT;
+               err = -ENOENT;
+               goto done;
        }
 
        brcmf_dbg(SCAN, "reqid=%llu\n", reqid);
@@ -78,14 +84,17 @@ static int brcmf_pno_remove_request(struct brcmf_pno_info *pi, u64 reqid)
 
        /* if last we are done */
        if (!pi->n_reqs || i == pi->n_reqs)
-               return 0;
+               goto done;
 
        /* fill the gap with remaining requests */
        while (i <= pi->n_reqs - 1) {
                pi->reqs[i] = pi->reqs[i + 1];
                i++;
        }
-       return 0;
+
+done:
+       mutex_unlock(&pi->req_lock);
+       return err;
 }
 
 static int brcmf_pno_channel_config(struct brcmf_if *ifp,
@@ -488,6 +497,7 @@ int brcmf_pno_attach(struct brcmf_cfg80211_info *cfg)
                return -ENOMEM;
 
        cfg->pno = pi;
+       mutex_init(&pi->req_lock);
        return 0;
 }
 
@@ -500,6 +510,7 @@ void brcmf_pno_detach(struct brcmf_cfg80211_info *cfg)
        cfg->pno = NULL;
 
        WARN_ON(pi->n_reqs);
+       mutex_destroy(&pi->req_lock);
        kfree(pi);
 }
 
@@ -515,11 +526,15 @@ void brcmf_pno_wiphy_params(struct wiphy *wiphy, bool gscan)
 
 u64 brcmf_pno_find_reqid_by_bucket(struct brcmf_pno_info *pi, u32 bucket)
 {
-       /* bucket appears to be gone */
-       if (bucket >= pi->n_reqs)
-               return 0;
+       u64 reqid = 0;
+
+       mutex_lock(&pi->req_lock);
+
+       if (bucket < pi->n_reqs)
+               reqid = pi->reqs[bucket]->reqid;
 
-       return pi->reqs[bucket]->reqid;
+       mutex_unlock(&pi->req_lock);
+       return reqid;
 }
 
 u32 brcmf_pno_get_bucket_map(struct brcmf_pno_info *pi,
@@ -530,6 +545,7 @@ u32 brcmf_pno_get_bucket_map(struct brcmf_pno_info *pi,
        u32 bucket_map = 0;
        int i, j;
 
+       mutex_lock(&pi->req_lock);
        for (i = 0; i < pi->n_reqs; i++) {
                req = pi->reqs[i];
 
@@ -544,5 +560,6 @@ u32 brcmf_pno_get_bucket_map(struct brcmf_pno_info *pi,
                        }
                }
        }
+       mutex_unlock(&pi->req_lock);
        return bucket_map;
 }