linux/net/mac80211/debugfs.c

712 lines
18 KiB

mac80211: Implement Airtime-based Queue Limit (AQL) In order for the Fq_CoDel algorithm integrated in mac80211 layer to operate effectively to control excessive queueing latency, the CoDel algorithm requires an accurate measure of how long packets stays in the queue, AKA sojourn time. The sojourn time measured at the mac80211 layer doesn't include queueing latency in the lower layer (firmware/hardware) and CoDel expects lower layer to have a short queue. However, most 802.11ac chipsets offload tasks such TX aggregation to firmware or hardware, thus have a deep lower layer queue. Without a mechanism to control the lower layer queue size, packets only stay in mac80211 layer transiently before being sent to firmware queue. As a result, the sojourn time measured by CoDel in the mac80211 layer is almost always lower than the CoDel latency target, hence CoDel does little to control the latency, even when the lower layer queue causes excessive latency. The Byte Queue Limits (BQL) mechanism is commonly used to address the similar issue with wired network interface. However, this method cannot be applied directly to the wireless network interface. "Bytes" is not a suitable measure of queue depth in the wireless network, as the data rate can vary dramatically from station to station in the same network, from a few Mbps to over Gbps. This patch implements an Airtime-based Queue Limit (AQL) to make CoDel work effectively with wireless drivers that utilized firmware/hardware offloading. AQL allows each txq to release just enough packets to the lower layer to form 1-2 large aggregations to keep hardware fully utilized and retains the rest of the frames in mac80211 layer to be controlled by the CoDel algorithm. Signed-off-by: Kan Yan <kyan@google.com> [ Toke: Keep API to set pending airtime internal, fix nits in commit msg ] Signed-off-by: Toke Høiland-Jørgensen <toke@redhat.com> Link: https://lore.kernel.org/r/20191119060610.76681-4-kyan@google.com Signed-off-by: Johannes Berg <johannes.berg@intel.com>
2019-11-18 22:06:09 -08:00
mac80211: Implement Airtime-based Queue Limit (AQL) In order for the Fq_CoDel algorithm integrated in mac80211 layer to operate effectively to control excessive queueing latency, the CoDel algorithm requires an accurate measure of how long packets stays in the queue, AKA sojourn time. The sojourn time measured at the mac80211 layer doesn't include queueing latency in the lower layer (firmware/hardware) and CoDel expects lower layer to have a short queue. However, most 802.11ac chipsets offload tasks such TX aggregation to firmware or hardware, thus have a deep lower layer queue. Without a mechanism to control the lower layer queue size, packets only stay in mac80211 layer transiently before being sent to firmware queue. As a result, the sojourn time measured by CoDel in the mac80211 layer is almost always lower than the CoDel latency target, hence CoDel does little to control the latency, even when the lower layer queue causes excessive latency. The Byte Queue Limits (BQL) mechanism is commonly used to address the similar issue with wired network interface. However, this method cannot be applied directly to the wireless network interface. "Bytes" is not a suitable measure of queue depth in the wireless network, as the data rate can vary dramatically from station to station in the same network, from a few Mbps to over Gbps. This patch implements an Airtime-based Queue Limit (AQL) to make CoDel work effectively with wireless drivers that utilized firmware/hardware offloading. AQL allows each txq to release just enough packets to the lower layer to form 1-2 large aggregations to keep hardware fully utilized and retains the rest of the frames in mac80211 layer to be controlled by the CoDel algorithm. Signed-off-by: Kan Yan <kyan@google.com> [ Toke: Keep API to set pending airtime internal, fix nits in commit msg ] Signed-off-by: Toke Høiland-Jørgensen <toke@redhat.com> Link: https://lore.kernel.org/r/20191119060610.76681-4-kyan@google.com Signed-off-by: Johannes Berg <johannes.berg@intel.com>
2019-11-18 22:06:09 -08:00
mac80211: Implement Airtime-based Queue Limit (AQL) In order for the Fq_CoDel algorithm integrated in mac80211 layer to operate effectively to control excessive queueing latency, the CoDel algorithm requires an accurate measure of how long packets stays in the queue, AKA sojourn time. The sojourn time measured at the mac80211 layer doesn't include queueing latency in the lower layer (firmware/hardware) and CoDel expects lower layer to have a short queue. However, most 802.11ac chipsets offload tasks such TX aggregation to firmware or hardware, thus have a deep lower layer queue. Without a mechanism to control the lower layer queue size, packets only stay in mac80211 layer transiently before being sent to firmware queue. As a result, the sojourn time measured by CoDel in the mac80211 layer is almost always lower than the CoDel latency target, hence CoDel does little to control the latency, even when the lower layer queue causes excessive latency. The Byte Queue Limits (BQL) mechanism is commonly used to address the similar issue with wired network interface. However, this method cannot be applied directly to the wireless network interface. "Bytes" is not a suitable measure of queue depth in the wireless network, as the data rate can vary dramatically from station to station in the same network, from a few Mbps to over Gbps. This patch implements an Airtime-based Queue Limit (AQL) to make CoDel work effectively with wireless drivers that utilized firmware/hardware offloading. AQL allows each txq to release just enough packets to the lower layer to form 1-2 large aggregations to keep hardware fully utilized and retains the rest of the frames in mac80211 layer to be controlled by the CoDel algorithm. Signed-off-by: Kan Yan <kyan@google.com> [ Toke: Keep API to set pending airtime internal, fix nits in commit msg ] Signed-off-by: Toke Høiland-Jørgensen <toke@redhat.com> Link: https://lore.kernel.org/r/20191119060610.76681-4-kyan@google.com Signed-off-by: Johannes Berg <johannes.berg@intel.com>
2019-11-18 22:06:09 -08:00
mac80211: Implement Airtime-based Queue Limit (AQL) In order for the Fq_CoDel algorithm integrated in mac80211 layer to operate effectively to control excessive queueing latency, the CoDel algorithm requires an accurate measure of how long packets stays in the queue, AKA sojourn time. The sojourn time measured at the mac80211 layer doesn't include queueing latency in the lower layer (firmware/hardware) and CoDel expects lower layer to have a short queue. However, most 802.11ac chipsets offload tasks such TX aggregation to firmware or hardware, thus have a deep lower layer queue. Without a mechanism to control the lower layer queue size, packets only stay in mac80211 layer transiently before being sent to firmware queue. As a result, the sojourn time measured by CoDel in the mac80211 layer is almost always lower than the CoDel latency target, hence CoDel does little to control the latency, even when the lower layer queue causes excessive latency. The Byte Queue Limits (BQL) mechanism is commonly used to address the similar issue with wired network interface. However, this method cannot be applied directly to the wireless network interface. "Bytes" is not a suitable measure of queue depth in the wireless network, as the data rate can vary dramatically from station to station in the same network, from a few Mbps to over Gbps. This patch implements an Airtime-based Queue Limit (AQL) to make CoDel work effectively with wireless drivers that utilized firmware/hardware offloading. AQL allows each txq to release just enough packets to the lower layer to form 1-2 large aggregations to keep hardware fully utilized and retains the rest of the frames in mac80211 layer to be controlled by the CoDel algorithm. Signed-off-by: Kan Yan <kyan@google.com> [ Toke: Keep API to set pending airtime internal, fix nits in commit msg ] Signed-off-by: Toke Høiland-Jørgensen <toke@redhat.com> Link: https://lore.kernel.org/r/20191119060610.76681-4-kyan@google.com Signed-off-by: Johannes Berg <johannes.berg@intel.com>
2019-11-18 22:06:09 -08:00
mac80211: Implement Airtime-based Queue Limit (AQL) In order for the Fq_CoDel algorithm integrated in mac80211 layer to operate effectively to control excessive queueing latency, the CoDel algorithm requires an accurate measure of how long packets stays in the queue, AKA sojourn time. The sojourn time measured at the mac80211 layer doesn't include queueing latency in the lower layer (firmware/hardware) and CoDel expects lower layer to have a short queue. However, most 802.11ac chipsets offload tasks such TX aggregation to firmware or hardware, thus have a deep lower layer queue. Without a mechanism to control the lower layer queue size, packets only stay in mac80211 layer transiently before being sent to firmware queue. As a result, the sojourn time measured by CoDel in the mac80211 layer is almost always lower than the CoDel latency target, hence CoDel does little to control the latency, even when the lower layer queue causes excessive latency. The Byte Queue Limits (BQL) mechanism is commonly used to address the similar issue with wired network interface. However, this method cannot be applied directly to the wireless network interface. "Bytes" is not a suitable measure of queue depth in the wireless network, as the data rate can vary dramatically from station to station in the same network, from a few Mbps to over Gbps. This patch implements an Airtime-based Queue Limit (AQL) to make CoDel work effectively with wireless drivers that utilized firmware/hardware offloading. AQL allows each txq to release just enough packets to the lower layer to form 1-2 large aggregations to keep hardware fully utilized and retains the rest of the frames in mac80211 layer to be controlled by the CoDel algorithm. Signed-off-by: Kan Yan <kyan@google.com> [ Toke: Keep API to set pending airtime internal, fix nits in commit msg ] Signed-off-by: Toke Høiland-Jørgensen <toke@redhat.com> Link: https://lore.kernel.org/r/20191119060610.76681-4-kyan@google.com Signed-off-by: Johannes Berg <johannes.berg@intel.com>
2019-11-18 22:06:09 -08:00
mac80211: Implement Airtime-based Queue Limit (AQL) In order for the Fq_CoDel algorithm integrated in mac80211 layer to operate effectively to control excessive queueing latency, the CoDel algorithm requires an accurate measure of how long packets stays in the queue, AKA sojourn time. The sojourn time measured at the mac80211 layer doesn't include queueing latency in the lower layer (firmware/hardware) and CoDel expects lower layer to have a short queue. However, most 802.11ac chipsets offload tasks such TX aggregation to firmware or hardware, thus have a deep lower layer queue. Without a mechanism to control the lower layer queue size, packets only stay in mac80211 layer transiently before being sent to firmware queue. As a result, the sojourn time measured by CoDel in the mac80211 layer is almost always lower than the CoDel latency target, hence CoDel does little to control the latency, even when the lower layer queue causes excessive latency. The Byte Queue Limits (BQL) mechanism is commonly used to address the similar issue with wired network interface. However, this method cannot be applied directly to the wireless network interface. "Bytes" is not a suitable measure of queue depth in the wireless network, as the data rate can vary dramatically from station to station in the same network, from a few Mbps to over Gbps. This patch implements an Airtime-based Queue Limit (AQL) to make CoDel work effectively with wireless drivers that utilized firmware/hardware offloading. AQL allows each txq to release just enough packets to the lower layer to form 1-2 large aggregations to keep hardware fully utilized and retains the rest of the frames in mac80211 layer to be controlled by the CoDel algorithm. Signed-off-by: Kan Yan <kyan@google.com> [ Toke: Keep API to set pending airtime internal, fix nits in commit msg ] Signed-off-by: Toke Høiland-Jørgensen <toke@redhat.com> Link: https://lore.kernel.org/r/20191119060610.76681-4-kyan@google.com Signed-off-by: Johannes Berg <johannes.berg@intel.com>
2019-11-18 22:06:09 -08:00
mac80211: Implement Airtime-based Queue Limit (AQL) In order for the Fq_CoDel algorithm integrated in mac80211 layer to operate effectively to control excessive queueing latency, the CoDel algorithm requires an accurate measure of how long packets stays in the queue, AKA sojourn time. The sojourn time measured at the mac80211 layer doesn't include queueing latency in the lower layer (firmware/hardware) and CoDel expects lower layer to have a short queue. However, most 802.11ac chipsets offload tasks such TX aggregation to firmware or hardware, thus have a deep lower layer queue. Without a mechanism to control the lower layer queue size, packets only stay in mac80211 layer transiently before being sent to firmware queue. As a result, the sojourn time measured by CoDel in the mac80211 layer is almost always lower than the CoDel latency target, hence CoDel does little to control the latency, even when the lower layer queue causes excessive latency. The Byte Queue Limits (BQL) mechanism is commonly used to address the similar issue with wired network interface. However, this method cannot be applied directly to the wireless network interface. "Bytes" is not a suitable measure of queue depth in the wireless network, as the data rate can vary dramatically from station to station in the same network, from a few Mbps to over Gbps. This patch implements an Airtime-based Queue Limit (AQL) to make CoDel work effectively with wireless drivers that utilized firmware/hardware offloading. AQL allows each txq to release just enough packets to the lower layer to form 1-2 large aggregations to keep hardware fully utilized and retains the rest of the frames in mac80211 layer to be controlled by the CoDel algorithm. Signed-off-by: Kan Yan <kyan@google.com> [ Toke: Keep API to set pending airtime internal, fix nits in commit msg ] Signed-off-by: Toke Høiland-Jørgensen <toke@redhat.com> Link: https://lore.kernel.org/r/20191119060610.76681-4-kyan@google.com Signed-off-by: Johannes Berg <johannes.berg@intel.com>
2019-11-18 22:06:09 -08:00
mac80211: Implement Airtime-based Queue Limit (AQL) In order for the Fq_CoDel algorithm integrated in mac80211 layer to operate effectively to control excessive queueing latency, the CoDel algorithm requires an accurate measure of how long packets stays in the queue, AKA sojourn time. The sojourn time measured at the mac80211 layer doesn't include queueing latency in the lower layer (firmware/hardware) and CoDel expects lower layer to have a short queue. However, most 802.11ac chipsets offload tasks such TX aggregation to firmware or hardware, thus have a deep lower layer queue. Without a mechanism to control the lower layer queue size, packets only stay in mac80211 layer transiently before being sent to firmware queue. As a result, the sojourn time measured by CoDel in the mac80211 layer is almost always lower than the CoDel latency target, hence CoDel does little to control the latency, even when the lower layer queue causes excessive latency. The Byte Queue Limits (BQL) mechanism is commonly used to address the similar issue with wired network interface. However, this method cannot be applied directly to the wireless network interface. "Bytes" is not a suitable measure of queue depth in the wireless network, as the data rate can vary dramatically from station to station in the same network, from a few Mbps to over Gbps. This patch implements an Airtime-based Queue Limit (AQL) to make CoDel work effectively with wireless drivers that utilized firmware/hardware offloading. AQL allows each txq to release just enough packets to the lower layer to form 1-2 large aggregations to keep hardware fully utilized and retains the rest of the frames in mac80211 layer to be controlled by the CoDel algorithm. Signed-off-by: Kan Yan <kyan@google.com> [ Toke: Keep API to set pending airtime internal, fix nits in commit msg ] Signed-off-by: Toke Høiland-Jørgensen <toke@redhat.com> Link: https://lore.kernel.org/r/20191119060610.76681-4-kyan@google.com Signed-off-by: Johannes Berg <johannes.berg@intel.com>
2019-11-18 22:06:09 -08:00
wifi: mac80211: Fix static_branch_dec() underflow for aql_disable. syzbot reported static_branch_dec() underflow in aql_enable_write(). [0] The problem is that aql_enable_write() does not serialise concurrent write()s to the debugfs. aql_enable_write() checks static_key_false(&aql_disable.key) and later calls static_branch_inc() or static_branch_dec(), but the state may change between the two calls. aql_disable does not need to track inc/dec. Let's use static_branch_enable() and static_branch_disable(). [0]: val == 0 WARNING: kernel/jump_label.c:311 at __static_key_slow_dec_cpuslocked.part.0+0x107/0x120 kernel/jump_label.c:311, CPU#0: syz.1.3155/20288 Modules linked in: CPU: 0 UID: 0 PID: 20288 Comm: syz.1.3155 Tainted: G U L syzkaller #0 PREEMPT(full) Tainted: [U]=USER, [L]=SOFTLOCKUP Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/24/2026 RIP: 0010:__static_key_slow_dec_cpuslocked.part.0+0x107/0x120 kernel/jump_label.c:311 Code: f2 c9 ff 5b 5d c3 cc cc cc cc e8 54 f2 c9 ff 48 89 df e8 ac f9 ff ff eb ad e8 45 f2 c9 ff 90 0f 0b 90 eb a2 e8 3a f2 c9 ff 90 <0f> 0b 90 eb 97 48 89 df e8 5c 4b 33 00 e9 36 ff ff ff 0f 1f 80 00 RSP: 0018:ffffc9000b9f7c10 EFLAGS: 00010293 RAX: 0000000000000000 RBX: ffffffff9b3e5d40 RCX: ffffffff823c57b4 RDX: ffff8880285a0000 RSI: ffffffff823c5846 RDI: ffff8880285a0000 RBP: 0000000000000000 R08: 0000000000000005 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000000 R12: 000000000000000a R13: 1ffff9200173ef88 R14: 0000000000000001 R15: ffffc9000b9f7e98 FS: 00007f530dd726c0(0000) GS:ffff8881245e3000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 0000200000001140 CR3: 000000007cc4a000 CR4: 00000000003526f0 Call Trace: <TASK> __static_key_slow_dec_cpuslocked kernel/jump_label.c:297 [inline] __static_key_slow_dec kernel/jump_label.c:321 [inline] static_key_slow_dec+0x7c/0xc0 kernel/jump_label.c:336 aql_enable_write+0x2b2/0x310 net/mac80211/debugfs.c:343 short_proxy_write+0x133/0x1a0 fs/debugfs/file.c:383 vfs_write+0x2aa/0x1070 fs/read_write.c:684 ksys_pwrite64 fs/read_write.c:793 [inline] __do_sys_pwrite64 fs/read_write.c:801 [inline] __se_sys_pwrite64 fs/read_write.c:798 [inline] __x64_sys_pwrite64+0x1eb/0x250 fs/read_write.c:798 do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline] do_syscall_64+0xc9/0xf80 arch/x86/entry/syscall_64.c:94 entry_SYSCALL_64_after_hwframe+0x77/0x7f RIP: 0033:0x7f530cf9aeb9 Code: ff c3 66 2e 0f 1f 84 00 00 00 00 00 0f 1f 44 00 00 48 89 f8 48 89 f7 48 89 d6 48 89 ca 4d 89 c2 4d 89 c8 4c 8b 4c 24 08 0f 05 <48> 3d 01 f0 ff ff 73 01 c3 48 c7 c1 e8 ff ff ff f7 d8 64 89 01 48 RSP: 002b:00007f530dd72028 EFLAGS: 00000246 ORIG_RAX: 0000000000000012 RAX: ffffffffffffffda RBX: 00007f530d215fa0 RCX: 00007f530cf9aeb9 RDX: 0000000000000003 RSI: 0000000000000000 RDI: 0000000000000010 RBP: 00007f530d008c1f R08: 0000000000000000 R09: 0000000000000000 R10: 4200000000000005 R11: 0000000000000246 R12: 0000000000000000 R13: 00007f530d216038 R14: 00007f530d215fa0 R15: 00007ffde89fb978 </TASK> Fixes: e908435e402a ("mac80211: introduce aql_enable node in debugfs") Reported-by: syzbot+feb9ce36a95341bb47a4@syzkaller.appspotmail.com Closes: https://lore.kernel.org/all/69a8979e.a70a0220.b118c.0025.GAE@google.com/ Signed-off-by: Kuniyuki Iwashima <kuniyu@google.com> Link: https://patch.msgid.link/20260306072405.3649474-1-kuniyu@google.com Signed-off-by: Johannes Berg <johannes.berg@intel.com>
2026-03-06 07:24:02 +00:00
mac80211: debugfs option to force TX status frames At Technical University of Munich we use MAC 802.11 TX status frames to perform several measurements in MAC 802.11 setups. With ath based drivers this was possible until commit d94a461d7a7df6 ("ath9k: use ieee80211_tx_status_noskb where possible") as the driver ignored the IEEE80211_TX_CTL_REQ_TX_STATUS flag and always delivered tx_status frames. Since that commit, this behavior was changed and the driver now adheres to IEEE80211_TX_CTL_REQ_TX_STATUS. Due to performance reasons, IEEE80211_TX_CTL_REQ_TX_STATUS is not set for data frames from interfaces in managed mode. Hence, frames that are sent from a managed mode interface do never deliver tx_status frames. This remains true even if a monitor mode interface (the measurement interface) is added to the same ieee80211 physical device. Thus, there is no possibility for receiving tx_status frames for frames sent on an interface in managed mode, if the driver adheres to IEEE80211_TX_CTL_REQ_TX_STATUS. In order to force delivery of tx_status frames for research and debugging purposes, implement a debugfs option force_tx_status for ieee80211 physical devices. When this option is set for a physical device, IEEE80211_TX_CTL_REQ_TX_STATUS is enabled in all packets sent from that device. This option can be set via /sys/kernel/debug/ieee80211/<dev>/force_tx_status. The default is disabled. Co-developed-by: Charlie Groh <ga58taw@mytum.de> Signed-off-by: Charlie Groh <ga58taw@mytum.de> Signed-off-by: Julius Niedworok <julius.n@gmx.net> Signed-off-by: Johannes Berg <johannes.berg@intel.com>
2019-03-28 21:01:06 +01:00
mac80211: debugfs option to force TX status frames At Technical University of Munich we use MAC 802.11 TX status frames to perform several measurements in MAC 802.11 setups. With ath based drivers this was possible until commit d94a461d7a7df6 ("ath9k: use ieee80211_tx_status_noskb where possible") as the driver ignored the IEEE80211_TX_CTL_REQ_TX_STATUS flag and always delivered tx_status frames. Since that commit, this behavior was changed and the driver now adheres to IEEE80211_TX_CTL_REQ_TX_STATUS. Due to performance reasons, IEEE80211_TX_CTL_REQ_TX_STATUS is not set for data frames from interfaces in managed mode. Hence, frames that are sent from a managed mode interface do never deliver tx_status frames. This remains true even if a monitor mode interface (the measurement interface) is added to the same ieee80211 physical device. Thus, there is no possibility for receiving tx_status frames for frames sent on an interface in managed mode, if the driver adheres to IEEE80211_TX_CTL_REQ_TX_STATUS. In order to force delivery of tx_status frames for research and debugging purposes, implement a debugfs option force_tx_status for ieee80211 physical devices. When this option is set for a physical device, IEEE80211_TX_CTL_REQ_TX_STATUS is enabled in all packets sent from that device. This option can be set via /sys/kernel/debug/ieee80211/<dev>/force_tx_status. The default is disabled. Co-developed-by: Charlie Groh <ga58taw@mytum.de> Signed-off-by: Charlie Groh <ga58taw@mytum.de> Signed-off-by: Julius Niedworok <julius.n@gmx.net> Signed-off-by: Johannes Berg <johannes.berg@intel.com>
2019-03-28 21:01:06 +01:00
mac80211: debugfs option to force TX status frames At Technical University of Munich we use MAC 802.11 TX status frames to perform several measurements in MAC 802.11 setups. With ath based drivers this was possible until commit d94a461d7a7df6 ("ath9k: use ieee80211_tx_status_noskb where possible") as the driver ignored the IEEE80211_TX_CTL_REQ_TX_STATUS flag and always delivered tx_status frames. Since that commit, this behavior was changed and the driver now adheres to IEEE80211_TX_CTL_REQ_TX_STATUS. Due to performance reasons, IEEE80211_TX_CTL_REQ_TX_STATUS is not set for data frames from interfaces in managed mode. Hence, frames that are sent from a managed mode interface do never deliver tx_status frames. This remains true even if a monitor mode interface (the measurement interface) is added to the same ieee80211 physical device. Thus, there is no possibility for receiving tx_status frames for frames sent on an interface in managed mode, if the driver adheres to IEEE80211_TX_CTL_REQ_TX_STATUS. In order to force delivery of tx_status frames for research and debugging purposes, implement a debugfs option force_tx_status for ieee80211 physical devices. When this option is set for a physical device, IEEE80211_TX_CTL_REQ_TX_STATUS is enabled in all packets sent from that device. This option can be set via /sys/kernel/debug/ieee80211/<dev>/force_tx_status. The default is disabled. Co-developed-by: Charlie Groh <ga58taw@mytum.de> Signed-off-by: Charlie Groh <ga58taw@mytum.de> Signed-off-by: Julius Niedworok <julius.n@gmx.net> Signed-off-by: Johannes Berg <johannes.berg@intel.com>
2019-03-28 21:01:06 +01:00
mac80211: debugfs option to force TX status frames At Technical University of Munich we use MAC 802.11 TX status frames to perform several measurements in MAC 802.11 setups. With ath based drivers this was possible until commit d94a461d7a7df6 ("ath9k: use ieee80211_tx_status_noskb where possible") as the driver ignored the IEEE80211_TX_CTL_REQ_TX_STATUS flag and always delivered tx_status frames. Since that commit, this behavior was changed and the driver now adheres to IEEE80211_TX_CTL_REQ_TX_STATUS. Due to performance reasons, IEEE80211_TX_CTL_REQ_TX_STATUS is not set for data frames from interfaces in managed mode. Hence, frames that are sent from a managed mode interface do never deliver tx_status frames. This remains true even if a monitor mode interface (the measurement interface) is added to the same ieee80211 physical device. Thus, there is no possibility for receiving tx_status frames for frames sent on an interface in managed mode, if the driver adheres to IEEE80211_TX_CTL_REQ_TX_STATUS. In order to force delivery of tx_status frames for research and debugging purposes, implement a debugfs option force_tx_status for ieee80211 physical devices. When this option is set for a physical device, IEEE80211_TX_CTL_REQ_TX_STATUS is enabled in all packets sent from that device. This option can be set via /sys/kernel/debug/ieee80211/<dev>/force_tx_status. The default is disabled. Co-developed-by: Charlie Groh <ga58taw@mytum.de> Signed-off-by: Charlie Groh <ga58taw@mytum.de> Signed-off-by: Julius Niedworok <julius.n@gmx.net> Signed-off-by: Johannes Berg <johannes.berg@intel.com>
2019-03-28 21:01:06 +01:00
mac80211: debugfs option to force TX status frames At Technical University of Munich we use MAC 802.11 TX status frames to perform several measurements in MAC 802.11 setups. With ath based drivers this was possible until commit d94a461d7a7df6 ("ath9k: use ieee80211_tx_status_noskb where possible") as the driver ignored the IEEE80211_TX_CTL_REQ_TX_STATUS flag and always delivered tx_status frames. Since that commit, this behavior was changed and the driver now adheres to IEEE80211_TX_CTL_REQ_TX_STATUS. Due to performance reasons, IEEE80211_TX_CTL_REQ_TX_STATUS is not set for data frames from interfaces in managed mode. Hence, frames that are sent from a managed mode interface do never deliver tx_status frames. This remains true even if a monitor mode interface (the measurement interface) is added to the same ieee80211 physical device. Thus, there is no possibility for receiving tx_status frames for frames sent on an interface in managed mode, if the driver adheres to IEEE80211_TX_CTL_REQ_TX_STATUS. In order to force delivery of tx_status frames for research and debugging purposes, implement a debugfs option force_tx_status for ieee80211 physical devices. When this option is set for a physical device, IEEE80211_TX_CTL_REQ_TX_STATUS is enabled in all packets sent from that device. This option can be set via /sys/kernel/debug/ieee80211/<dev>/force_tx_status. The default is disabled. Co-developed-by: Charlie Groh <ga58taw@mytum.de> Signed-off-by: Charlie Groh <ga58taw@mytum.de> Signed-off-by: Julius Niedworok <julius.n@gmx.net> Signed-off-by: Johannes Berg <johannes.berg@intel.com>
2019-03-28 21:01:06 +01:00
llseek: automatically add .llseek fop All file_operations should get a .llseek operation so we can make nonseekable_open the default for future file operations without a .llseek pointer. The three cases that we can automatically detect are no_llseek, seq_lseek and default_llseek. For cases where we can we can automatically prove that the file offset is always ignored, we use noop_llseek, which maintains the current behavior of not returning an error from a seek. New drivers should normally not use noop_llseek but instead use no_llseek and call nonseekable_open at open time. Existing drivers can be converted to do the same when the maintainer knows for certain that no user code relies on calling seek on the device file. The generated code is often incorrectly indented and right now contains comments that clarify for each added line why a specific variant was chosen. In the version that gets submitted upstream, the comments will be gone and I will manually fix the indentation, because there does not seem to be a way to do that using coccinelle. Some amount of new code is currently sitting in linux-next that should get the same modifications, which I will do at the end of the merge window. Many thanks to Julia Lawall for helping me learn to write a semantic patch that does all this. ===== begin semantic patch ===== // This adds an llseek= method to all file operations, // as a preparation for making no_llseek the default. // // The rules are // - use no_llseek explicitly if we do nonseekable_open // - use seq_lseek for sequential files // - use default_llseek if we know we access f_pos // - use noop_llseek if we know we don't access f_pos, // but we still want to allow users to call lseek // @ open1 exists @ identifier nested_open; @@ nested_open(...) { <+... nonseekable_open(...) ...+> } @ open exists@ identifier open_f; identifier i, f; identifier open1.nested_open; @@ int open_f(struct inode *i, struct file *f) { <+... ( nonseekable_open(...) | nested_open(...) ) ...+> } @ read disable optional_qualifier exists @ identifier read_f; identifier f, p, s, off; type ssize_t, size_t, loff_t; expression E; identifier func; @@ ssize_t read_f(struct file *f, char *p, size_t s, loff_t *off) { <+... ( *off = E | *off += E | func(..., off, ...) | E = *off ) ...+> } @ read_no_fpos disable optional_qualifier exists @ identifier read_f; identifier f, p, s, off; type ssize_t, size_t, loff_t; @@ ssize_t read_f(struct file *f, char *p, size_t s, loff_t *off) { ... when != off } @ write @ identifier write_f; identifier f, p, s, off; type ssize_t, size_t, loff_t; expression E; identifier func; @@ ssize_t write_f(struct file *f, const char *p, size_t s, loff_t *off) { <+... ( *off = E | *off += E | func(..., off, ...) | E = *off ) ...+> } @ write_no_fpos @ identifier write_f; identifier f, p, s, off; type ssize_t, size_t, loff_t; @@ ssize_t write_f(struct file *f, const char *p, size_t s, loff_t *off) { ... when != off } @ fops0 @ identifier fops; @@ struct file_operations fops = { ... }; @ has_llseek depends on fops0 @ identifier fops0.fops; identifier llseek_f; @@ struct file_operations fops = { ... .llseek = llseek_f, ... }; @ has_read depends on fops0 @ identifier fops0.fops; identifier read_f; @@ struct file_operations fops = { ... .read = read_f, ... }; @ has_write depends on fops0 @ identifier fops0.fops; identifier write_f; @@ struct file_operations fops = { ... .write = write_f, ... }; @ has_open depends on fops0 @ identifier fops0.fops; identifier open_f; @@ struct file_operations fops = { ... .open = open_f, ... }; // use no_llseek if we call nonseekable_open //////////////////////////////////////////// @ nonseekable1 depends on !has_llseek && has_open @ identifier fops0.fops; identifier nso ~= "nonseekable_open"; @@ struct file_operations fops = { ... .open = nso, ... +.llseek = no_llseek, /* nonseekable */ }; @ nonseekable2 depends on !has_llseek @ identifier fops0.fops; identifier open.open_f; @@ struct file_operations fops = { ... .open = open_f, ... +.llseek = no_llseek, /* open uses nonseekable */ }; // use seq_lseek for sequential files ///////////////////////////////////// @ seq depends on !has_llseek @ identifier fops0.fops; identifier sr ~= "seq_read"; @@ struct file_operations fops = { ... .read = sr, ... +.llseek = seq_lseek, /* we have seq_read */ }; // use default_llseek if there is a readdir /////////////////////////////////////////// @ fops1 depends on !has_llseek && !nonseekable1 && !nonseekable2 && !seq @ identifier fops0.fops; identifier readdir_e; @@ // any other fop is used that changes pos struct file_operations fops = { ... .readdir = readdir_e, ... +.llseek = default_llseek, /* readdir is present */ }; // use default_llseek if at least one of read/write touches f_pos ///////////////////////////////////////////////////////////////// @ fops2 depends on !fops1 && !has_llseek && !nonseekable1 && !nonseekable2 && !seq @ identifier fops0.fops; identifier read.read_f; @@ // read fops use offset struct file_operations fops = { ... .read = read_f, ... +.llseek = default_llseek, /* read accesses f_pos */ }; @ fops3 depends on !fops1 && !fops2 && !has_llseek && !nonseekable1 && !nonseekable2 && !seq @ identifier fops0.fops; identifier write.write_f; @@ // write fops use offset struct file_operations fops = { ... .write = write_f, ... + .llseek = default_llseek, /* write accesses f_pos */ }; // Use noop_llseek if neither read nor write accesses f_pos /////////////////////////////////////////////////////////// @ fops4 depends on !fops1 && !fops2 && !fops3 && !has_llseek && !nonseekable1 && !nonseekable2 && !seq @ identifier fops0.fops; identifier read_no_fpos.read_f; identifier write_no_fpos.write_f; @@ // write fops use offset struct file_operations fops = { ... .write = write_f, .read = read_f, ... +.llseek = noop_llseek, /* read and write both use no f_pos */ }; @ depends on has_write && !has_read && !fops1 && !fops2 && !has_llseek && !nonseekable1 && !nonseekable2 && !seq @ identifier fops0.fops; identifier write_no_fpos.write_f; @@ struct file_operations fops = { ... .write = write_f, ... +.llseek = noop_llseek, /* write uses no f_pos */ }; @ depends on has_read && !has_write && !fops1 && !fops2 && !has_llseek && !nonseekable1 && !nonseekable2 && !seq @ identifier fops0.fops; identifier read_no_fpos.read_f; @@ struct file_operations fops = { ... .read = read_f, ... +.llseek = noop_llseek, /* read uses no f_pos */ }; @ depends on !has_read && !has_write && !fops1 && !fops2 && !has_llseek && !nonseekable1 && !nonseekable2 && !seq @ identifier fops0.fops; @@ struct file_operations fops = { ... +.llseek = noop_llseek, /* no read or write fn */ }; ===== End semantic patch ===== Signed-off-by: Arnd Bergmann <arnd@arndb.de> Cc: Julia Lawall <julia@diku.dk> Cc: Christoph Hellwig <hch@infradead.org>
2010-08-15 18:52:59 +02:00
wifi: mac80211: add support for NDP ADDBA/DELBA for S1G S1G defines use of NDP Block Ack (BA) for aggregation, requiring negotiation of NDP ADDBA/DELBA action frames. If the S1G recipient supports HT-immediate block ack, the sender must send an NDP ADDBA Request indicating it expects only NDP BlockAck frames for the agreement. Introduce support for NDP ADDBA and DELBA exchange in mac80211. The implementation negotiates the BA mechanism during setup based on station capabilities and driver support (IEEE80211_HW_SUPPORTS_NDP_BLOCKACK). If negotiation fails due to mismatched expectations, a rejection with status code WLAN_STATUS_REJECTED_NDP_BLOCK_ACK_SUGGESTED is returned as per IEEE 802.11-2024. Trace sample: IEEE 802.11 Wireless Management Fixed parameters Category code: Block Ack (3) Action code: NDP ADDBA Request (0x80) Dialog token: 0x01 Block Ack Parameters: 0x1003, A-MSDUs, Block Ack Policy .... .... .... ...1 = A-MSDUs: Permitted in QoS Data MPDUs .... .... .... ..1. = Block Ack Policy: Immediate Block Ack .... .... ..00 00.. = Traffic Identifier: 0x0 0001 0000 00.. .... = Number of Buffers (1 Buffer = 2304 Bytes): 64 Block Ack Timeout: 0x0000 Block Ack Starting Sequence Control (SSC): 0x0010 .... .... .... 0000 = Fragment: 0 0000 0000 0001 .... = Starting Sequence Number: 1 IEEE 802.11 Wireless Management Fixed parameters Category code: Block Ack (3) Action code: NDP ADDBA Response (0x81) Dialog token: 0x02 Status code: BlockAck negotiation refused because, due to buffer constraints and other unspecified reasons, the recipient prefers to generate only NDP BlockAck frames (0x006d) Block Ack Parameters: 0x1002, Block Ack Policy .... .... .... ...0 = A-MSDUs: Not Permitted .... .... .... ..1. = Block Ack Policy: Immediate Block Ack .... .... ..00 00.. = Traffic Identifier: 0x0 0001 0000 00.. .... = Number of Buffers (1 Buffer = 2304 Bytes): 64 Block Ack Timeout: 0x0000 Signed-off-by: Ria Thomas <ria.thomas@morsemicro.com> Link: https://patch.msgid.link/20260305091304.310990-1-ria.thomas@morsemicro.com Signed-off-by: Johannes Berg <johannes.berg@intel.com>
2026-03-05 14:43:04 +05:30
mac80211: debugfs option to force TX status frames At Technical University of Munich we use MAC 802.11 TX status frames to perform several measurements in MAC 802.11 setups. With ath based drivers this was possible until commit d94a461d7a7df6 ("ath9k: use ieee80211_tx_status_noskb where possible") as the driver ignored the IEEE80211_TX_CTL_REQ_TX_STATUS flag and always delivered tx_status frames. Since that commit, this behavior was changed and the driver now adheres to IEEE80211_TX_CTL_REQ_TX_STATUS. Due to performance reasons, IEEE80211_TX_CTL_REQ_TX_STATUS is not set for data frames from interfaces in managed mode. Hence, frames that are sent from a managed mode interface do never deliver tx_status frames. This remains true even if a monitor mode interface (the measurement interface) is added to the same ieee80211 physical device. Thus, there is no possibility for receiving tx_status frames for frames sent on an interface in managed mode, if the driver adheres to IEEE80211_TX_CTL_REQ_TX_STATUS. In order to force delivery of tx_status frames for research and debugging purposes, implement a debugfs option force_tx_status for ieee80211 physical devices. When this option is set for a physical device, IEEE80211_TX_CTL_REQ_TX_STATUS is enabled in all packets sent from that device. This option can be set via /sys/kernel/debug/ieee80211/<dev>/force_tx_status. The default is disabled. Co-developed-by: Charlie Groh <ga58taw@mytum.de> Signed-off-by: Charlie Groh <ga58taw@mytum.de> Signed-off-by: Julius Niedworok <julius.n@gmx.net> Signed-off-by: Johannes Berg <johannes.berg@intel.com>
2019-03-28 21:01:06 +01:00
mac80211: Add airtime accounting and scheduling to TXQs This adds airtime accounting and scheduling to the mac80211 TXQ scheduler. A new callback, ieee80211_sta_register_airtime(), is added that drivers can call to report airtime usage for stations. When airtime information is present, mac80211 will schedule TXQs (through ieee80211_next_txq()) in a way that enforces airtime fairness between active stations. This scheduling works the same way as the ath9k in-driver airtime fairness scheduling. If no airtime usage is reported by the driver, the scheduler will default to round-robin scheduling. For drivers that don't control TXQ scheduling in software, a new API function, ieee80211_txq_may_transmit(), is added which the driver can use to check if the TXQ is eligible for transmission, or should be throttled to enforce fairness. Calls to this function must also be enclosed in ieee80211_txq_schedule_{start,end}() calls to ensure proper locking. The API ieee80211_txq_may_transmit() also ensures that TXQ list will be aligned aginst driver's own round-robin scheduler list. i.e it rotates the TXQ list till it makes the requested node becomes the first entry in TXQ list. Thus both the TXQ list and driver's list are in sync. Co-developed-by: Rajkumar Manoharan <rmanohar@codeaurora.org> Signed-off-by: Louie Lu <git@louie.lu> [added debugfs write op to reset airtime counter] Signed-off-by: Toke Høiland-Jørgensen <toke@toke.dk> Signed-off-by: Rajkumar Manoharan <rmanohar@codeaurora.org> Signed-off-by: Johannes Berg <johannes.berg@intel.com>
2018-12-18 17:02:08 -08:00
mac80211: Implement Airtime-based Queue Limit (AQL) In order for the Fq_CoDel algorithm integrated in mac80211 layer to operate effectively to control excessive queueing latency, the CoDel algorithm requires an accurate measure of how long packets stays in the queue, AKA sojourn time. The sojourn time measured at the mac80211 layer doesn't include queueing latency in the lower layer (firmware/hardware) and CoDel expects lower layer to have a short queue. However, most 802.11ac chipsets offload tasks such TX aggregation to firmware or hardware, thus have a deep lower layer queue. Without a mechanism to control the lower layer queue size, packets only stay in mac80211 layer transiently before being sent to firmware queue. As a result, the sojourn time measured by CoDel in the mac80211 layer is almost always lower than the CoDel latency target, hence CoDel does little to control the latency, even when the lower layer queue causes excessive latency. The Byte Queue Limits (BQL) mechanism is commonly used to address the similar issue with wired network interface. However, this method cannot be applied directly to the wireless network interface. "Bytes" is not a suitable measure of queue depth in the wireless network, as the data rate can vary dramatically from station to station in the same network, from a few Mbps to over Gbps. This patch implements an Airtime-based Queue Limit (AQL) to make CoDel work effectively with wireless drivers that utilized firmware/hardware offloading. AQL allows each txq to release just enough packets to the lower layer to form 1-2 large aggregations to keep hardware fully utilized and retains the rest of the frames in mac80211 layer to be controlled by the CoDel algorithm. Signed-off-by: Kan Yan <kyan@google.com> [ Toke: Keep API to set pending airtime internal, fix nits in commit msg ] Signed-off-by: Toke Høiland-Jørgensen <toke@redhat.com> Link: https://lore.kernel.org/r/20191119060610.76681-4-kyan@google.com Signed-off-by: Johannes Berg <johannes.berg@intel.com>
2019-11-18 22:06:09 -08:00