[PATCH v4 06/11] wifi: rtw88: iterate over vif/sta list non-atomically

Sascha Hauer
2022-11-29T10:09:09Z

The driver uses ieee80211_iterate_active_interfaces_atomic()
and ieee80211_iterate_stations_atomic() in several places and does
register accesses in the iterators. This doesn't cope with upcoming
USB support as registers can only be accessed non-atomically.

Split these into a two stage process: First use the atomic iterator
functions to collect all active interfaces or stations on a list, then
iterate over the list non-atomically and call the iterator on each
entry.

Signed-off-by: Sascha Hauer <s.hauer@pengutronix.de>
Suggested-by: Ping-Ke shih <pkshih@realtek.com>
Reviewed-by: Ping-Ke Shih <pkshih@realtek.com>
---

Notes:
Changes since v1:
- Change subject
- Add some lockdep_assert_held(&rtwdev->mutex);
- make locally used functions static
- Add comment how &rtwdev->mutex protects us from stations/interfaces
being deleted between collecting them and iterating over them.

drivers/net/wireless/realtek/rtw88/phy.c | 6 +-
drivers/net/wireless/realtek/rtw88/ps.c | 2 +-
drivers/net/wireless/realtek/rtw88/util.c | 103 ++++++++++++++++++++++
drivers/net/wireless/realtek/rtw88/util.h | 12 ++-
4 files changed, 116 insertions(+), 7 deletions(-)

diff --git a/drivers/net/wireless/realtek/rtw88/phy.c b/drivers/net/wireless/realtek/rtw88/phy.c
index bd7d05e080848..128e75a81bf3c 100644
--- a/drivers/net/wireless/realtek/rtw88/phy.c
+++ b/drivers/net/wireless/realtek/rtw88/phy.c
@@ -300,7 +300,7 @@ static void rtw_phy_stat_rssi(struct rtw_dev *rtwdev)

data.rtwdev = rtwdev;
data.min_rssi = U8_MAX;
- rtw_iterate_stas_atomic(rtwdev, rtw_phy_stat_rssi_iter, &data);
+ rtw_iterate_stas(rtwdev, rtw_phy_stat_rssi_iter, &data);

dm_info->pre_min_rssi = dm_info->min_rssi;
dm_info->min_rssi = data.min_rssi;
@@ -544,7 +544,7 @@ static void rtw_phy_ra_info_update(struct rtw_dev *rtwdev)
if (rtwdev->watch_dog_cnt & 0x3)
return;

- rtw_iterate_stas_atomic(rtwdev, rtw_phy_ra_info_update_iter, rtwdev);
+ rtw_iterate_stas(rtwdev, rtw_phy_ra_info_update_iter, rtwdev);
}

static u32 rtw_phy_get_rrsr_mask(struct rtw_dev *rtwdev, u8 rate_idx)
@@ -597,7 +597,7 @@ static void rtw_phy_rrsr_update(struct rtw_dev *rtwdev)
struct rtw_dm_info *dm_info = &rtwdev->dm_info;

dm_info->rrsr_mask_min = RRSR_RATE_ORDER_MAX;
- rtw_iterate_stas_atomic(rtwdev, rtw_phy_rrsr_mask_min_iter, rtwdev);
+ rtw_iterate_stas(rtwdev, rtw_phy_rrsr_mask_min_iter, rtwdev);
rtw_write32(rtwdev, REG_RRSR, dm_info->rrsr_val_init & dm_info->rrsr_mask_min);
}

diff --git a/drivers/net/wireless/realtek/rtw88/ps.c b/drivers/net/wireless/realtek/rtw88/ps.c
index c93da743681fc..11594940d6b00 100644
--- a/drivers/net/wireless/realtek/rtw88/ps.c
+++ b/drivers/net/wireless/realtek/rtw88/ps.c
@@ -61,7 +61,7 @@ int rtw_leave_ips(struct rtw_dev *rtwdev)
return ret;
}

- rtw_iterate_vifs_atomic(rtwdev, rtw_restore_port_cfg_iter, rtwdev);
+ rtw_iterate_vifs(rtwdev, rtw_restore_port_cfg_iter, rtwdev);

rtw_coex_ips_notify(rtwdev, COEX_IPS_LEAVE);

diff --git a/drivers/net/wireless/realtek/rtw88/util.c b/drivers/net/wireless/realtek/rtw88/util.c
index cdfd66a85075a..ff3c269fb1a72 100644
--- a/drivers/net/wireless/realtek/rtw88/util.c
+++ b/drivers/net/wireless/realtek/rtw88/util.c
@@ -105,3 +105,106 @@ void rtw_desc_to_mcsrate(u16 rate, u8 *mcs, u8 *nss)
*mcs = rate - DESC_RATEMCS0;
}
}
+
+struct rtw_stas_entry {
+ struct list_head list;
+ struct ieee80211_sta *sta;
+};
+
+struct rtw_iter_stas_data {
+ struct rtw_dev *rtwdev;
+ struct list_head list;
+};
+
+static void rtw_collect_sta_iter(void *data, struct ieee80211_sta *sta)
+{
+ struct rtw_iter_stas_data *iter_stas = data;
+ struct rtw_stas_entry *stas_entry;
+
+ stas_entry = kmalloc(sizeof(*stas_entry), GFP_ATOMIC);
+ if (!stas_entry)
+ return;
+
+ stas_entry->sta = sta;
+ list_add_tail(&stas_entry->list, &iter_stas->list);
+}
+
+void rtw_iterate_stas(struct rtw_dev *rtwdev,
+ void (*iterator)(void *data,
+ struct ieee80211_sta *sta),
+ void *data)
+{
+ struct rtw_iter_stas_data iter_data;
+ struct rtw_stas_entry *sta_entry, *tmp;
+
+ /* &rtwdev->mutex makes sure no stations can be removed between
+ * collecting the stations and iterating over them.
+ */
+ lockdep_assert_held(&rtwdev->mutex);
+
+ iter_data.rtwdev = rtwdev;
+ INIT_LIST_HEAD(&iter_data.list);
+
+ ieee80211_iterate_stations_atomic(rtwdev->hw, rtw_collect_sta_iter,
+ &iter_data);
+
+ list_for_each_entry_safe(sta_entry, tmp, &iter_data.list,
+ list) {
+ list_del_init(&sta_entry->list);
+ iterator(data, sta_entry->sta);
+ kfree(sta_entry);
+ }
+}
+
+struct rtw_vifs_entry {
+ struct list_head list;
+ struct ieee80211_vif *vif;
+ u8 mac[ETH_ALEN];
+};
+
+struct rtw_iter_vifs_data {
+ struct rtw_dev *rtwdev;
+ struct list_head list;
+};
+
+static void rtw_collect_vif_iter(void *data, u8 *mac, struct ieee80211_vif *vif)
+{
+ struct rtw_iter_vifs_data *iter_stas = data;
+ struct rtw_vifs_entry *vifs_entry;
+
+ vifs_entry = kmalloc(sizeof(*vifs_entry), GFP_ATOMIC);
+ if (!vifs_entry)
+ return;
+
+ vifs_entry->vif = vif;
+ ether_addr_copy(vifs_entry->mac, mac);
+ list_add_tail(&vifs_entry->list, &iter_stas->list);
+}
+
+void rtw_iterate_vifs(struct rtw_dev *rtwdev,
+ void (*iterator)(void *data, u8 *mac,
+ struct ieee80211_vif *vif),
+ void *data)
+{
+ struct rtw_iter_vifs_data iter_data;
+ struct rtw_vifs_entry *vif_entry, *tmp;
+
+ /* &rtwdev->mutex makes sure no interfaces can be removed between
+ * collecting the interfaces and iterating over them.
+ */
+ lockdep_assert_held(&rtwdev->mutex);
+
+ iter_data.rtwdev = rtwdev;
+ INIT_LIST_HEAD(&iter_data.list);
+
+ ieee80211_iterate_active_interfaces_atomic(rtwdev->hw,
+ IEEE80211_IFACE_ITER_NORMAL,
+ rtw_collect_vif_iter, &iter_data);
+
+ list_for_each_entry_safe(vif_entry, tmp, &iter_data.list,
+ list) {
+ list_del_init(&vif_entry->list);
+ iterator(data, vif_entry->mac, vif_entry->vif);
+ kfree(vif_entry);
+ }
+}
diff --git a/drivers/net/wireless/realtek/rtw88/util.h b/drivers/net/wireless/realtek/rtw88/util.h
index 0c23b5069be0b..dc89655254002 100644
--- a/drivers/net/wireless/realtek/rtw88/util.h
+++ b/drivers/net/wireless/realtek/rtw88/util.h
@@ -7,9 +7,6 @@

struct rtw_dev;

-#define rtw_iterate_vifs(rtwdev, iterator, data) \
- ieee80211_iterate_active_interfaces(rtwdev->hw, \
- IEEE80211_IFACE_ITER_NORMAL, iterator, data)
#define rtw_iterate_vifs_atomic(rtwdev, iterator, data) \
ieee80211_iterate_active_interfaces_atomic(rtwdev->hw, \
IEEE80211_IFACE_ITER_NORMAL, iterator, data)
@@ -20,6 +17,15 @@ struct rtw_dev;
#define rtw_iterate_keys_rcu(rtwdev, vif, iterator, data) \
ieee80211_iter_keys_rcu((rtwdev)->hw, vif, iterator, data)

+void rtw_iterate_vifs(struct rtw_dev *rtwdev,
+ void (*iterator)(void *data, u8 *mac,
+ struct ieee80211_vif *vif),
+ void *data);
+void rtw_iterate_stas(struct rtw_dev *rtwdev,
+ void (*iterator)(void *data,
+ struct ieee80211_sta *sta),
+ void *data);
+
static inline u8 *get_hdr_bssid(struct ieee80211_hdr *hdr)
{
__le16 fc = hdr->frame_control;
--
2.30.2