[PATCH 6/21] d80211: get rid of sta_aid in favour of keeping track of TIM
From: Jiri Benc <hidden>
Date: 2006-08-23 19:24:15
Subsystem:
networking [general], the rest · Maintainers:
"David S. Miller", Eric Dumazet, Jakub Kicinski, Paolo Abeni, Linus Torvalds
From: Johannes Berg <johannes@sipsolutions.net> This patch gets rid of the HUGE sta_aid array that was there in the access point structure and instead keeps track of the TIM. Also reduces stack usage of the ieee80211_beacon_add_tim() function considerably, and fixes a bug where removing a station that had frames buffered wouldn't update the hardware TIM (if necessary). It also removes the MAX_AID_TABLE_SIZE pseudo-configuration option (it was a define with a comment indicating it could be changed) since now having all AIDs available is no longer expensive. Signed-off-by: Johannes Berg <johannes@sipsolutions.net> Signed-off-by: Jiri Benc <redacted> --- include/net/d80211.h | 3 ++ net/d80211/ieee80211.c | 68 ++++++++++++++++++++++-------------------- net/d80211/ieee80211_i.h | 28 +++++++++++++---- net/d80211/ieee80211_ioctl.c | 6 +--- net/d80211/ieee80211_sysfs.c | 2 - net/d80211/sta_info.c | 15 ++++----- net/d80211/sta_info.h | 4 -- 7 files changed, 68 insertions(+), 58 deletions(-) 358fd4b6115683d3a8f88308268cfd6062c31f47
diff --git a/include/net/d80211.h b/include/net/d80211.h
index ba5cb4c..da1892f 100644
--- a/include/net/d80211.h
+++ b/include/net/d80211.h@@ -967,8 +967,11 @@ #define IEEE80211_STYPE_QOS_CFPOLL 0x00 #define IEEE80211_STYPE_QOS_CFACKPOLL 0x00F0 +/* miscellaneous IEEE 802.11 constants */ #define IEEE80211_MAX_FRAG_THRESHOLD 2346 #define IEEE80211_MAX_RTS_THRESHOLD 2347 +#define IEEE80211_MAX_AID 2007 +#define IEEE80211_MAX_TIM_LEN 251 struct ieee80211_hdr { __le16 frame_control;
diff --git a/net/d80211/ieee80211.c b/net/d80211/ieee80211.c
index 05a88f1..1846d3e 100644
--- a/net/d80211/ieee80211.c
+++ b/net/d80211/ieee80211.c@@ -21,6 +21,7 @@ #include <linux/wireless.h> #include <linux/rtnetlink.h> #include <net/iw_handler.h> #include <linux/compiler.h> +#include <linux/bitmap.h> #include <net/d80211.h> #include <net/d80211_common.h>
@@ -1047,8 +1048,12 @@ #endif /* IEEE80211_VERBOSE_DEBUG_PS */ } else tx->local->total_ps_buffered++; /* Queue frame to be sent after STA sends an PS Poll frame */ - if (skb_queue_empty(&sta->ps_tx_buf) && tx->local->hw->set_tim) - tx->local->hw->set_tim(tx->dev, sta->aid, 1); + if (skb_queue_empty(&sta->ps_tx_buf)) { + if (tx->local->hw->set_tim) + tx->local->hw->set_tim(tx->dev, sta->aid, 1); + if (tx->sdata->bss) + bss_tim_set(tx->local, tx->sdata->bss, sta->aid); + } pkt_data = (struct ieee80211_tx_packet_data *)tx->skb->cb; pkt_data->jiffies = jiffies; skb_queue_tail(&sta->ps_tx_buf, tx->skb);
@@ -1687,25 +1692,16 @@ static void ieee80211_beacon_add_tim(str { u8 *pos, *tim; int aid0 = 0; - int i, num_bits = 0, n1, n2; - u8 bitmap[251]; + int i, have_bits = 0, n1, n2; /* Generate bitmap for TIM only if there are any STAs in power save * mode. */ - if (atomic_read(&bss->num_sta_ps) > 0 && bss->max_aid > 0) { - memset(bitmap, 0, sizeof(bitmap)); - spin_lock_bh(&local->sta_lock); - for (i = 0; i < bss->max_aid; i++) { - if (bss->sta_aid[i] && - (!skb_queue_empty(&bss->sta_aid[i]->ps_tx_buf) || - !skb_queue_empty(&bss->sta_aid[i]->tx_filtered))) - { - bitmap[(i + 1) / 8] |= 1 << (i + 1) % 8; - num_bits++; - } - } - spin_unlock_bh(&local->sta_lock); - } + spin_lock_bh(&local->sta_lock); + if (atomic_read(&bss->num_sta_ps) > 0) + /* in the hope that this is faster than + * checking byte-for-byte */ + have_bits = !bitmap_empty((unsigned long*)bss->tim, + IEEE80211_MAX_AID+1); if (bss->dtim_count == 0) bss->dtim_count = bss->dtim_period - 1;
@@ -1718,40 +1714,40 @@ static void ieee80211_beacon_add_tim(str *pos++ = bss->dtim_count; *pos++ = bss->dtim_period; - if (bss->dtim_count == 0 && !skb_queue_empty(&bss->ps_bc_buf)) { + if (bss->dtim_count == 0 && !skb_queue_empty(&bss->ps_bc_buf)) aid0 = 1; - } - if (num_bits) { + if (have_bits) { /* Find largest even number N1 so that bits numbered 1 through * (N1 x 8) - 1 in the bitmap are 0 and number N2 so that bits * (N2 + 1) x 8 through 2007 are 0. */ n1 = 0; - for (i = 0; i < sizeof(bitmap); i++) { - if (bitmap[i]) { + for (i = 0; i < IEEE80211_MAX_TIM_LEN; i++) { + if (bss->tim[i]) { n1 = i & 0xfe; break; } } n2 = n1; - for (i = sizeof(bitmap) - 1; i >= n1; i--) { - if (bitmap[i]) { + for (i = IEEE80211_MAX_TIM_LEN - 1; i >= n1; i--) { + if (bss->tim[i]) { n2 = i; break; } } /* Bitmap control */ - *pos++ = n1 | (aid0 ? 1 : 0); + *pos++ = n1 | aid0; /* Part Virt Bitmap */ - memcpy(pos, bitmap + n1, n2 - n1 + 1); + memcpy(pos, bss->tim + n1, n2 - n1 + 1); tim[1] = n2 - n1 + 4; skb_put(skb, n2 - n1); } else { - *pos++ = aid0 ? 1 : 0; /* Bitmap control */ + *pos++ = aid0; /* Bitmap control */ *pos++ = 0; /* Part Virt Bitmap */ } + spin_unlock_bh(&local->sta_lock); }
@@ -2713,8 +2709,12 @@ static int ap_sta_ps_end(struct net_devi atomic_dec(&sdata->bss->num_sta_ps); sta->flags &= ~(WLAN_STA_PS | WLAN_STA_TIM); sta->pspoll = 0; - if (!skb_queue_empty(&sta->ps_tx_buf) && local->hw->set_tim) - local->hw->set_tim(dev, sta->aid, 0); + if (!skb_queue_empty(&sta->ps_tx_buf)) { + if (local->hw->set_tim) + local->hw->set_tim(dev, sta->aid, 0); + if (sdata->bss) + bss_tim_clear(local, sdata->bss, sta->aid); + } #ifdef IEEE80211_VERBOSE_DEBUG_PS printk(KERN_DEBUG "%s: STA " MAC_FMT " aid %d exits power " "save mode\n", dev->name, MAC_ARG(sta->addr), sta->aid);
@@ -2789,8 +2789,12 @@ #endif /* IEEE80211_VERBOSE_DEBUG_PS */ dev_queue_xmit(skb); - if (no_pending_pkts && rx->local->hw->set_tim) - rx->local->hw->set_tim(rx->dev, rx->sta->aid, 0); + if (no_pending_pkts) { + if (rx->local->hw->set_tim) + rx->local->hw->set_tim(rx->dev, rx->sta->aid, 0); + if (rx->sdata->bss) + bss_tim_clear(rx->local, rx->sdata->bss, rx->sta->aid); + } #ifdef IEEE80211_VERBOSE_DEBUG_PS } else if (!rx->u.rx.sent_ps_buffered) { printk(KERN_DEBUG "%s: STA " MAC_FMT " sent PS Poll even "
diff --git a/net/d80211/ieee80211_i.h b/net/d80211/ieee80211_i.h
index bdaaf5e..f38eea0 100644
--- a/net/d80211/ieee80211_i.h
+++ b/net/d80211/ieee80211_i.h@@ -18,6 +18,8 @@ #include <linux/list.h> #include <linux/netdevice.h> #include <linux/skbuff.h> #include <linux/workqueue.h> +#include <linux/types.h> +#include <linux/spinlock.h> #include "ieee80211_key.h" #include "sta_info.h"
@@ -211,13 +213,10 @@ struct ieee80211_if_ap { u8 *generic_elem; size_t generic_elem_len; - /* TODO: sta_aid could be replaced by 2008-bit large bitfield of - * that could be used in TIM element generation. This would also - * make TIM element generation a bit faster. */ - /* AID mapping to station data. NULL, if AID is free. AID is in the - * range 1..2007 and sta_aid[i] corresponds to AID i+1. */ - struct sta_info *sta_aid[MAX_AID_TABLE_SIZE]; - int max_aid; /* largest aid currently in use */ + /* yes, this looks ugly, but guarantees that we can later use + * bitmap_empty :) + * NB: don't ever use set_bit, use bss_tim_set/bss_tim_clear! */ + u8 tim[sizeof(unsigned long) * BITS_TO_LONGS(IEEE80211_MAX_AID + 1)]; atomic_t num_sta_ps; /* number of stations in PS mode */ struct sk_buff_head ps_bc_buf; int dtim_period, dtim_count;
@@ -545,6 +544,21 @@ struct sta_attribute { ssize_t (*store)(struct sta_info *, const char *buf, size_t count); }; +static inline void bss_tim_set(struct ieee80211_local *local, + struct ieee80211_if_ap *bss, int aid) +{ + spin_lock(&local->sta_lock); + bss->tim[(aid)/8] |= 1<<((aid) % 8); + spin_unlock(&local->sta_lock); +} + +static inline void bss_tim_clear(struct ieee80211_local *local, + struct ieee80211_if_ap *bss, int aid) +{ + spin_lock(&local->sta_lock); + bss->tim[(aid)/8] &= !(1<<((aid) % 8)); + spin_unlock(&local->sta_lock); +} /* ieee80211.c */ void ieee80211_release_hw(struct ieee80211_local *local);
diff --git a/net/d80211/ieee80211_ioctl.c b/net/d80211/ieee80211_ioctl.c
index f134f2a..db8e8ba 100644
--- a/net/d80211/ieee80211_ioctl.c
+++ b/net/d80211/ieee80211_ioctl.c@@ -296,12 +296,8 @@ static int ieee80211_ioctl_add_sta(struc sta->flags |= WLAN_STA_AUTH | WLAN_STA_ASSOC; sta->aid = param->u.add_sta.aid; - if (sta->aid > MAX_AID_TABLE_SIZE) + if (sta->aid > IEEE80211_MAX_AID) sta->aid = 0; - if (sta->aid > 0 && sdata->bss) - sdata->bss->sta_aid[sta->aid - 1] = sta; - if (sdata->bss && sta->aid > sdata->bss->max_aid) - sdata->bss->max_aid = sta->aid; rates = 0; for (i = 0; i < sizeof(param->u.add_sta.supp_rates); i++) {
diff --git a/net/d80211/ieee80211_sysfs.c b/net/d80211/ieee80211_sysfs.c
index 6725ff7..bb93723 100644
--- a/net/d80211/ieee80211_sysfs.c
+++ b/net/d80211/ieee80211_sysfs.c@@ -471,7 +471,6 @@ static ssize_t ieee80211_if_fmt_flags(co __IEEE80211_IF_SHOW(flags); /* AP attributes */ -IEEE80211_IF_SHOW(max_aid, u.ap.max_aid, DEC); IEEE80211_IF_SHOW(num_sta_ps, u.ap.num_sta_ps, ATOMIC); IEEE80211_IF_SHOW(dtim_period, u.ap.dtim_period, DEC); IEEE80211_IF_SHOW(dtim_count, u.ap.dtim_count, DEC);
@@ -549,7 +548,6 @@ static struct attribute *ieee80211_ap_at &class_device_attr_drop_unencrypted.attr, &class_device_attr_eapol.attr, &class_device_attr_ieee8021_x.attr, - &class_device_attr_max_aid.attr, &class_device_attr_num_sta_ps.attr, &class_device_attr_dtim_period.attr, &class_device_attr_dtim_count.attr,
diff --git a/net/d80211/sta_info.c b/net/d80211/sta_info.c
index d8f044e..dd5bc97 100644
--- a/net/d80211/sta_info.c
+++ b/net/d80211/sta_info.c@@ -421,16 +421,15 @@ void sta_info_remove_aid_ptr(struct sta_ { struct ieee80211_sub_if_data *sdata; - sdata = IEEE80211_DEV_TO_SUB_IF(sta->dev); - if (sta->aid <= 0 || !sdata->bss) + if (sta->aid <= 0) return; - sdata->bss->sta_aid[sta->aid - 1] = NULL; - if (sta->aid == sdata->bss->max_aid) { - while (sdata->bss->max_aid > 0 && - !sdata->bss->sta_aid[sdata->bss->max_aid - 1]) - sdata->bss->max_aid--; - } + sdata = IEEE80211_DEV_TO_SUB_IF(sta->dev); + + if (sdata->local->hw->set_tim) + sdata->local->hw->set_tim(sta->dev, sta->aid, 0); + if (sdata->bss) + bss_tim_clear(sdata->local, sdata->bss, sta->aid); }
diff --git a/net/d80211/sta_info.h b/net/d80211/sta_info.h
index 70334e5..1f0f845 100644
--- a/net/d80211/sta_info.h
+++ b/net/d80211/sta_info.h@@ -114,10 +114,6 @@ #endif /* CONFIG_D80211_DEBUG_COUNTERS * /* Maximum number of concurrently registered stations */ #define MAX_STA_COUNT 2007 -/* Maximum number of AIDs to use for STAs; must be 2007 or lower - * (IEEE 802.11 beacon format limitation) */ -#define MAX_AID_TABLE_SIZE 2007 - #define STA_HASH_SIZE 256 #define STA_HASH(sta) (sta[5])
--
1.3.0