diff mbox series

[1/8] wifi: ath12k: Add MLO station state change handling

Message ID 20241106142617.660901-2-kvalo@kernel.org (mailing list archive)
State Under Review
Delegated to: Jeff Johnson
Headers show
Series wifi: ath12k: MLO support part 3 | expand

Commit Message

Kalle Valo Nov. 6, 2024, 2:26 p.m. UTC
From: Sriram R <quic_srirrama@quicinc.com>

Add changes to handle multi-link station state change with proper
link handling and add code changes for ML peer creation, peer deletion.

In ath12k_mac_assign_link_sta() initialise all arsta fields first and only then
call rcu_assign_pointer(). This is to make sure that readers don't have access
to arsta which is still modified.

Tested-on: QCN9274 hw2.0 PCI WLAN.WBE.1.3.1-00173-QCAHKSWPL_SILICONZ-1
Tested-on: WCN7850 hw2.0 PCI WLAN.HMT.1.0.c5-00481-QCAHMTSWPL_V1.0_V2.0_SILICONZ-3

Signed-off-by: Sriram R <quic_srirrama@quicinc.com>
Signed-off-by: Harshitha Prem <quic_hprem@quicinc.com>
Signed-off-by: Kalle Valo <quic_kvalo@quicinc.com>
---
 drivers/net/wireless/ath/ath12k/core.h |   4 +
 drivers/net/wireless/ath/ath12k/mac.c  | 235 +++++++++++++++++++++----
 drivers/net/wireless/ath/ath12k/mac.h  |   1 +
 drivers/net/wireless/ath/ath12k/peer.c |  92 +++++++++-
 drivers/net/wireless/ath/ath12k/peer.h |   1 +
 5 files changed, 294 insertions(+), 39 deletions(-)

Comments

Jeff Johnson Nov. 6, 2024, 4:33 p.m. UTC | #1
On 11/6/2024 6:26 AM, Kalle Valo wrote:
> From: Sriram R <quic_srirrama@quicinc.com>
> 
> Add changes to handle multi-link station state change with proper
> link handling and add code changes for ML peer creation, peer deletion.
> 
> In ath12k_mac_assign_link_sta() initialise all arsta fields first and only then
> call rcu_assign_pointer(). This is to make sure that readers don't have access
> to arsta which is still modified.
> 
> Tested-on: QCN9274 hw2.0 PCI WLAN.WBE.1.3.1-00173-QCAHKSWPL_SILICONZ-1
> Tested-on: WCN7850 hw2.0 PCI WLAN.HMT.1.0.c5-00481-QCAHMTSWPL_V1.0_V2.0_SILICONZ-3
> 
> Signed-off-by: Sriram R <quic_srirrama@quicinc.com>
> Signed-off-by: Harshitha Prem <quic_hprem@quicinc.com>
> Signed-off-by: Kalle Valo <quic_kvalo@quicinc.com>
Acked-by: Jeff Johnson <quic_jjohnson@quicinc.com>
Baochen Qiang Nov. 7, 2024, 2:26 a.m. UTC | #2
On 11/6/2024 10:26 PM, Kalle Valo wrote:
> +static int ath12k_mac_assign_link_sta(struct ath12k_hw *ah,
> +				      struct ath12k_sta *ahsta,
> +				      struct ath12k_link_sta *arsta,
> +				      struct ath12k_vif *ahvif,
> +				      u8 link_id)
> +{
> +	struct ieee80211_sta *sta = ath12k_ahsta_to_sta(ahsta);
> +	struct ieee80211_link_sta *link_sta;
> +	struct ath12k_link_vif *arvif;
> +
> +	lockdep_assert_wiphy(ah->hw->wiphy);
> +
> +	if (!arsta || link_id >= IEEE80211_MLD_MAX_NUM_LINKS)
> +		return -EINVAL;
> +
> +	arvif = wiphy_dereference(ah->hw->wiphy, ahvif->link[link_id]);
> +	if (!arvif)
> +		return -EINVAL;
> +
> +	memset(arsta, 0, sizeof(*arsta));
> +
> +	link_sta = wiphy_dereference(ah->hw->wiphy, sta->link[link_id]);
> +	if (!link_sta)
> +		return -EINVAL;
> +
> +	ether_addr_copy(arsta->addr, link_sta->addr);
> +
> +	/* logical index of the link sta in order of creation */
> +	arsta->link_idx = ahsta->num_peer++;
> +
> +	arsta->link_id = link_id;
> +	ahsta->links_map |= BIT(arsta->link_id);
would be better to put this after rcu_assign_pointer()?

> +	arsta->arvif = arvif;
> +	arsta->ahsta = ahsta;
> +	arsta->state = IEEE80211_STA_NONE;
> +	wiphy_work_init(&arsta->update_wk, ath12k_sta_rc_update_wk);
> +
> +	rcu_assign_pointer(ahsta->link[link_id], arsta);
> +
> +	synchronize_rcu();
what are we waiting for here?

> +
> +	return 0;
> +}
> +
Baochen Qiang Nov. 7, 2024, 2:45 a.m. UTC | #3
On 11/6/2024 10:26 PM, Kalle Valo wrote:
> +static void ath12k_mac_unassign_link_sta(struct ath12k_hw *ah,
> +					 struct ath12k_sta *ahsta,
> +					 u8 link_id)
> +{
> +	lockdep_assert_wiphy(ah->hw->wiphy);
> +
> +	ahsta->links_map &= ~BIT(link_id);
> +	rcu_assign_pointer(ahsta->link[link_id], NULL);
> +
> +	synchronize_rcu();
this looks strange: generally we call synchronize_rcu() to wait for any RCU readers to finish, such that we can then safely free something. but here we do nothing ...

> +}
> +
> +static void ath12k_mac_free_unassign_link_sta(struct ath12k_hw *ah,
> +					      struct ath12k_sta *ahsta,
> +					      u8 link_id)
> +{
> +	struct ath12k_link_sta *arsta;
> +
> +	lockdep_assert_wiphy(ah->hw->wiphy);
> +
> +	if (WARN_ON(link_id >= IEEE80211_MLD_MAX_NUM_LINKS))
> +		return;
> +
> +	arsta = wiphy_dereference(ah->hw->wiphy, ahsta->link[link_id]);
> +
> +	if (WARN_ON(!arsta))
> +		return;
> +
> +	ath12k_mac_unassign_link_sta(ah, ahsta, link_id);
> +
> +	arsta->link_id = ATH12K_INVALID_LINK_ID;
> +	arsta->ahsta = NULL;
> +	arsta->arvif = NULL;
if arsta is not deflink and would be freed, can we avoid these cleanup?

> +
> +	if (arsta != &ahsta->deflink)
> +		kfree(arsta);
I know the actual free happens here, but why split them?

these two hunks give me the impression that we may (in the future?) have cases to call ath12k_mac_unassign_link_sta() alone somewhere else rather than directly calling ath12k_mac_free_unassign_link_sta(). am I feeling right? what are those cases?

> +}
> +
Kalle Valo Nov. 12, 2024, 4:03 p.m. UTC | #4
Baochen Qiang <quic_bqiang@quicinc.com> writes:

> On 11/6/2024 10:26 PM, Kalle Valo wrote:
>> +static int ath12k_mac_assign_link_sta(struct ath12k_hw *ah,
>> +				      struct ath12k_sta *ahsta,
>> +				      struct ath12k_link_sta *arsta,
>> +				      struct ath12k_vif *ahvif,
>> +				      u8 link_id)
>> +{
>> +	struct ieee80211_sta *sta = ath12k_ahsta_to_sta(ahsta);
>> +	struct ieee80211_link_sta *link_sta;
>> +	struct ath12k_link_vif *arvif;
>> +
>> +	lockdep_assert_wiphy(ah->hw->wiphy);
>> +
>> +	if (!arsta || link_id >= IEEE80211_MLD_MAX_NUM_LINKS)
>> +		return -EINVAL;
>> +
>> +	arvif = wiphy_dereference(ah->hw->wiphy, ahvif->link[link_id]);
>> +	if (!arvif)
>> +		return -EINVAL;
>> +
>> +	memset(arsta, 0, sizeof(*arsta));
>> +
>> +	link_sta = wiphy_dereference(ah->hw->wiphy, sta->link[link_id]);
>> +	if (!link_sta)
>> +		return -EINVAL;
>> +
>> +	ether_addr_copy(arsta->addr, link_sta->addr);
>> +
>> +	/* logical index of the link sta in order of creation */
>> +	arsta->link_idx = ahsta->num_peer++;
>> +
>> +	arsta->link_id = link_id;
>> +	ahsta->links_map |= BIT(arsta->link_id);
>
> would be better to put this after rcu_assign_pointer()?

My thinking is that it's racy anyway so it doesn't really matter.
links_map is not really protected properly right now but luckily there's
only one function which accesses outside of the wiphy lock. My plan is
to fix that in a later patch.

>> +	arsta->arvif = arvif;
>> +	arsta->ahsta = ahsta;
>> +	arsta->state = IEEE80211_STA_NONE;
>> +	wiphy_work_init(&arsta->update_wk, ath12k_sta_rc_update_wk);
>> +
>> +	rcu_assign_pointer(ahsta->link[link_id], arsta);
>> +
>> +	synchronize_rcu();
>
> what are we waiting for here?

That's a good question. I didn't analyse that thoroughly but I'm just
making sure here that all readers have access to the new arsta before we
return to mac80211. The delay shouldn't be that long anyway, I hope.
Kalle Valo Nov. 12, 2024, 5:10 p.m. UTC | #5
Baochen Qiang <quic_bqiang@quicinc.com> writes:

> On 11/6/2024 10:26 PM, Kalle Valo wrote:
>> +static void ath12k_mac_unassign_link_sta(struct ath12k_hw *ah,
>> +					 struct ath12k_sta *ahsta,
>> +					 u8 link_id)
>> +{
>> +	lockdep_assert_wiphy(ah->hw->wiphy);
>> +
>> +	ahsta->links_map &= ~BIT(link_id);
>> +	rcu_assign_pointer(ahsta->link[link_id], NULL);
>> +
>> +	synchronize_rcu();
>
> this looks strange: generally we call synchronize_rcu() to wait for
> any RCU readers to finish, such that we can then safely free
> something. but here we do nothing ...

Same comment as in the other email, this is to make sure that we don't
continue the mac80211 call flow before all readers have the new value.
Is that a problem? And we can always optimise later.

>> +static void ath12k_mac_free_unassign_link_sta(struct ath12k_hw *ah,
>> +					      struct ath12k_sta *ahsta,
>> +					      u8 link_id)
>> +{
>> +	struct ath12k_link_sta *arsta;
>> +
>> +	lockdep_assert_wiphy(ah->hw->wiphy);
>> +
>> +	if (WARN_ON(link_id >= IEEE80211_MLD_MAX_NUM_LINKS))
>> +		return;
>> +
>> +	arsta = wiphy_dereference(ah->hw->wiphy, ahsta->link[link_id]);
>> +
>> +	if (WARN_ON(!arsta))
>> +		return;
>> +
>> +	ath12k_mac_unassign_link_sta(ah, ahsta, link_id);
>> +
>> +	arsta->link_id = ATH12K_INVALID_LINK_ID;
>> +	arsta->ahsta = NULL;
>> +	arsta->arvif = NULL;
>
> if arsta is not deflink and would be freed, can we avoid these
> cleanup?

I think that's something we can cleanup later if needed. Sure, it's
extra assignments but it's not really doing any harm.

>> +	if (arsta != &ahsta->deflink)
>> +		kfree(arsta);
>
> I know the actual free happens here, but why split them?

You mean why have a separate function ath12k_mac_unassign_link_sta() and
instead just have all code the in ath12k_mac_free_unassign_link_sta()?

> these two hunks give me the impression that we may (in the future?)
> have cases to call ath12k_mac_unassign_link_sta() alone somewhere else
> rather than directly calling ath12k_mac_free_unassign_link_sta(). am I
> feeling right? what are those cases?

At least I'm not aware of anything else calling
ath12k_mac_unassign_link_sta(). So I'll just remove that function and
move the code to ath12k_mac_free_unassign_link_sta().
Baochen Qiang Nov. 13, 2024, 2:33 a.m. UTC | #6
On 11/13/2024 12:03 AM, Kalle Valo wrote:
> Baochen Qiang <quic_bqiang@quicinc.com> writes:
> 
>> On 11/6/2024 10:26 PM, Kalle Valo wrote:
>>> +static int ath12k_mac_assign_link_sta(struct ath12k_hw *ah,
>>> +				      struct ath12k_sta *ahsta,
>>> +				      struct ath12k_link_sta *arsta,
>>> +				      struct ath12k_vif *ahvif,
>>> +				      u8 link_id)
>>> +{
>>> +	struct ieee80211_sta *sta = ath12k_ahsta_to_sta(ahsta);
>>> +	struct ieee80211_link_sta *link_sta;
>>> +	struct ath12k_link_vif *arvif;
>>> +
>>> +	lockdep_assert_wiphy(ah->hw->wiphy);
>>> +
>>> +	if (!arsta || link_id >= IEEE80211_MLD_MAX_NUM_LINKS)
>>> +		return -EINVAL;
>>> +
>>> +	arvif = wiphy_dereference(ah->hw->wiphy, ahvif->link[link_id]);
>>> +	if (!arvif)
>>> +		return -EINVAL;
>>> +
>>> +	memset(arsta, 0, sizeof(*arsta));
>>> +
>>> +	link_sta = wiphy_dereference(ah->hw->wiphy, sta->link[link_id]);
>>> +	if (!link_sta)
>>> +		return -EINVAL;
>>> +
>>> +	ether_addr_copy(arsta->addr, link_sta->addr);
>>> +
>>> +	/* logical index of the link sta in order of creation */
>>> +	arsta->link_idx = ahsta->num_peer++;
>>> +
>>> +	arsta->link_id = link_id;
>>> +	ahsta->links_map |= BIT(arsta->link_id);
>>
>> would be better to put this after rcu_assign_pointer()?
> 
> My thinking is that it's racy anyway so it doesn't really matter.
> links_map is not really protected properly right now but luckily there's
> only one function which accesses outside of the wiphy lock. My plan is
> to fix that in a later patch.
> 
>>> +	arsta->arvif = arvif;
>>> +	arsta->ahsta = ahsta;
>>> +	arsta->state = IEEE80211_STA_NONE;
>>> +	wiphy_work_init(&arsta->update_wk, ath12k_sta_rc_update_wk);
>>> +
>>> +	rcu_assign_pointer(ahsta->link[link_id], arsta);
>>> +
>>> +	synchronize_rcu();
>>
>> what are we waiting for here?
> 
> That's a good question. I didn't analyse that thoroughly but I'm just
> making sure here that all readers have access to the new arsta before we
> return to mac80211. 
why would readers have to access arsta BEFORE returning to mac80211? any potential race conditions?

and even if it is necessary, how could synchronize_rcu() guarantee that? synchronize_rcu() is used to make sure all readers have exited from RCU read critical section, I don;t see how it could make sure a newly assigned entry get accessed.

> The delay shouldn't be that long anyway, I hope.
>
Baochen Qiang Nov. 13, 2024, 2:55 a.m. UTC | #7
On 11/13/2024 1:10 AM, Kalle Valo wrote:
> Baochen Qiang <quic_bqiang@quicinc.com> writes:
> 
>> On 11/6/2024 10:26 PM, Kalle Valo wrote:
>>> +static void ath12k_mac_unassign_link_sta(struct ath12k_hw *ah,
>>> +					 struct ath12k_sta *ahsta,
>>> +					 u8 link_id)
>>> +{
>>> +	lockdep_assert_wiphy(ah->hw->wiphy);
>>> +
>>> +	ahsta->links_map &= ~BIT(link_id);
>>> +	rcu_assign_pointer(ahsta->link[link_id], NULL);
>>> +
>>> +	synchronize_rcu();
>>
>> this looks strange: generally we call synchronize_rcu() to wait for
>> any RCU readers to finish, such that we can then safely free
>> something. but here we do nothing ...
> 
> Same comment as in the other email, this is to make sure that we don't
> continue the mac80211 call flow before all readers have the new value.
> Is that a problem? And we can always optimise later.
here this is a different situation from that in the other email you referred to: we are clearing an RCU pointer here, so a synchronize_rcu() is necessary for the purpose of safely freeing arsta. But ideally the code flow should look like:

	rcu_assign_pointer(ahsta->link[link_id], NULL)	
	synchronize_rcu()
	if (arsta != &ahsta->deflink)
		kfree(arsta);

However the patch is doing nothing after synchronize_rcu().

I know the actual free happens immediately after ath12k_mac_unassign_link_sta() returns, so there should be no problem. But it really looks odd to get them split.

> 
>>> +static void ath12k_mac_free_unassign_link_sta(struct ath12k_hw *ah,
>>> +					      struct ath12k_sta *ahsta,
>>> +					      u8 link_id)
>>> +{
>>> +	struct ath12k_link_sta *arsta;
>>> +
>>> +	lockdep_assert_wiphy(ah->hw->wiphy);
>>> +
>>> +	if (WARN_ON(link_id >= IEEE80211_MLD_MAX_NUM_LINKS))
>>> +		return;
>>> +
>>> +	arsta = wiphy_dereference(ah->hw->wiphy, ahsta->link[link_id]);
>>> +
>>> +	if (WARN_ON(!arsta))
>>> +		return;
>>> +
>>> +	ath12k_mac_unassign_link_sta(ah, ahsta, link_id);
>>> +
>>> +	arsta->link_id = ATH12K_INVALID_LINK_ID;
>>> +	arsta->ahsta = NULL;
>>> +	arsta->arvif = NULL;
>>
>> if arsta is not deflink and would be freed, can we avoid these
>> cleanup?
> 
> I think that's something we can cleanup later if needed. Sure, it's
> extra assignments but it's not really doing any harm.
exactly, but ideally we should avoid unnecessary effort if possible.

> 
>>> +	if (arsta != &ahsta->deflink)
>>> +		kfree(arsta);
>>
>> I know the actual free happens here, but why split them?
> 
> You mean why have a separate function ath12k_mac_unassign_link_sta() and
> instead just have all code the in ath12k_mac_free_unassign_link_sta()?
yes. such that we can have synchronize_rcu() and kfree() located together.

> 
>> these two hunks give me the impression that we may (in the future?)
>> have cases to call ath12k_mac_unassign_link_sta() alone somewhere else
>> rather than directly calling ath12k_mac_free_unassign_link_sta(). am I
>> feeling right? what are those cases?
> 
> At least I'm not aware of anything else calling
> ath12k_mac_unassign_link_sta(). So I'll just remove that function and
> move the code to ath12k_mac_free_unassign_link_sta().
>
Kalle Valo Nov. 20, 2024, 3:57 p.m. UTC | #8
Baochen Qiang <quic_bqiang@quicinc.com> writes:

>>>> +	arsta->arvif = arvif;
>>>> +	arsta->ahsta = ahsta;
>>>> +	arsta->state = IEEE80211_STA_NONE;
>>>> +	wiphy_work_init(&arsta->update_wk, ath12k_sta_rc_update_wk);
>>>> +
>>>> +	rcu_assign_pointer(ahsta->link[link_id], arsta);
>>>> +
>>>> +	synchronize_rcu();
>>>
>>> what are we waiting for here?
>> 
>> That's a good question. I didn't analyse that thoroughly but I'm just
>> making sure here that all readers have access to the new arsta before we
>> return to mac80211.
>
> why would readers have to access arsta BEFORE returning to mac80211?
> any potential race conditions?
>
> and even if it is necessary, how could synchronize_rcu() guarantee
> that? synchronize_rcu() is used to make sure all readers have exited
> from RCU read critical section, I don;t see how it could make sure a
> newly assigned entry get accessed.

Yeah, I'm not making any sense. I'll remove synchronize_rcu() in v2.
Kalle Valo Nov. 20, 2024, 7:32 p.m. UTC | #9
Baochen Qiang <quic_bqiang@quicinc.com> writes:

>>>> +static void ath12k_mac_free_unassign_link_sta(struct ath12k_hw *ah,
>>>> +					      struct ath12k_sta *ahsta,
>>>> +					      u8 link_id)
>>>> +{
>>>> +	struct ath12k_link_sta *arsta;
>>>> +
>>>> +	lockdep_assert_wiphy(ah->hw->wiphy);
>>>> +
>>>> +	if (WARN_ON(link_id >= IEEE80211_MLD_MAX_NUM_LINKS))
>>>> +		return;
>>>> +
>>>> +	arsta = wiphy_dereference(ah->hw->wiphy, ahsta->link[link_id]);
>>>> +
>>>> +	if (WARN_ON(!arsta))
>>>> +		return;
>>>> +
>>>> +	ath12k_mac_unassign_link_sta(ah, ahsta, link_id);
>>>> +
>>>> +	arsta->link_id = ATH12K_INVALID_LINK_ID;
>>>> +	arsta->ahsta = NULL;
>>>> +	arsta->arvif = NULL;
>>>
>>> if arsta is not deflink and would be freed, can we avoid these
>>> cleanup?
>> 
>> I think that's something we can cleanup later if needed. Sure, it's
>> extra assignments but it's not really doing any harm.
> exactly, but ideally we should avoid unnecessary effort if possible.
>
>> 
>>>> +	if (arsta != &ahsta->deflink)
>>>> +		kfree(arsta);
>>>
>>> I know the actual free happens here, but why split them?
>> 
>> You mean why have a separate function ath12k_mac_unassign_link_sta() and
>> instead just have all code the in
>> ath12k_mac_free_unassign_link_sta()?
>
> yes. such that we can have synchronize_rcu() and kfree() located together.

Ok, I think I now get what you mean. Does this look better:

static void ath12k_mac_free_unassign_link_sta(struct ath12k_hw *ah,
					      struct ath12k_sta *ahsta,
					      u8 link_id)
{
	struct ath12k_link_sta *arsta;

	lockdep_assert_wiphy(ah->hw->wiphy);

	if (WARN_ON(link_id >= IEEE80211_MLD_MAX_NUM_LINKS))
		return;

	arsta = wiphy_dereference(ah->hw->wiphy, ahsta->link[link_id]);
	if (WARN_ON(!arsta))
		return;

	ahsta->links_map &= ~BIT(link_id);
	rcu_assign_pointer(ahsta->link[link_id], NULL);

	if (arsta == &ahsta->deflink) {
		arsta->link_id = ATH12K_INVALID_LINK_ID;
		arsta->ahsta = NULL;
		arsta->arvif = NULL;
		return;
	}

	synchronize_rcu();
	kfree(arsta);
}

BTW your lines are really long, please check your settings:

https://patchwork.kernel.org/project/linux-wireless/patch/20241106142617.660901-2-kvalo@kernel.org/
Baochen Qiang Nov. 21, 2024, 3:35 a.m. UTC | #10
On 11/21/2024 3:32 AM, Kalle Valo wrote:
> Baochen Qiang <quic_bqiang@quicinc.com> writes:
> 
>>>>> +static void ath12k_mac_free_unassign_link_sta(struct ath12k_hw *ah,
>>>>> +					      struct ath12k_sta *ahsta,
>>>>> +					      u8 link_id)
>>>>> +{
>>>>> +	struct ath12k_link_sta *arsta;
>>>>> +
>>>>> +	lockdep_assert_wiphy(ah->hw->wiphy);
>>>>> +
>>>>> +	if (WARN_ON(link_id >= IEEE80211_MLD_MAX_NUM_LINKS))
>>>>> +		return;
>>>>> +
>>>>> +	arsta = wiphy_dereference(ah->hw->wiphy, ahsta->link[link_id]);
>>>>> +
>>>>> +	if (WARN_ON(!arsta))
>>>>> +		return;
>>>>> +
>>>>> +	ath12k_mac_unassign_link_sta(ah, ahsta, link_id);
>>>>> +
>>>>> +	arsta->link_id = ATH12K_INVALID_LINK_ID;
>>>>> +	arsta->ahsta = NULL;
>>>>> +	arsta->arvif = NULL;
>>>>
>>>> if arsta is not deflink and would be freed, can we avoid these
>>>> cleanup?
>>>
>>> I think that's something we can cleanup later if needed. Sure, it's
>>> extra assignments but it's not really doing any harm.
>> exactly, but ideally we should avoid unnecessary effort if possible.
>>
>>>
>>>>> +	if (arsta != &ahsta->deflink)
>>>>> +		kfree(arsta);
>>>>
>>>> I know the actual free happens here, but why split them?
>>>
>>> You mean why have a separate function ath12k_mac_unassign_link_sta() and
>>> instead just have all code the in
>>> ath12k_mac_free_unassign_link_sta()?
>>
>> yes. such that we can have synchronize_rcu() and kfree() located together.
> 
> Ok, I think I now get what you mean. Does this look better:
> 
> static void ath12k_mac_free_unassign_link_sta(struct ath12k_hw *ah,
> 					      struct ath12k_sta *ahsta,
> 					      u8 link_id)
> {
> 	struct ath12k_link_sta *arsta;
> 
> 	lockdep_assert_wiphy(ah->hw->wiphy);
> 
> 	if (WARN_ON(link_id >= IEEE80211_MLD_MAX_NUM_LINKS))
> 		return;
> 
> 	arsta = wiphy_dereference(ah->hw->wiphy, ahsta->link[link_id]);
> 	if (WARN_ON(!arsta))
> 		return;
> 
> 	ahsta->links_map &= ~BIT(link_id);
> 	rcu_assign_pointer(ahsta->link[link_id], NULL);
below synchronize_rcu() should be moved to here, such that any change to arsta can happen only AFTER all existing RCU readers finish accessing it.

> 
> 	if (arsta == &ahsta->deflink) {
> 		arsta->link_id = ATH12K_INVALID_LINK_ID;
> 		arsta->ahsta = NULL;
> 		arsta->arvif = NULL;
> 		return;
> 	}
> 
> 	synchronize_rcu();
> 	kfree(arsta);
> }
other than that this change looks good to me.

> 
> BTW your lines are really long, please check your settings:
sure, will check.

> 
> https://patchwork.kernel.org/project/linux-wireless/patch/20241106142617.660901-2-kvalo@kernel.org/
>
Kalle Valo Nov. 21, 2024, 2:51 p.m. UTC | #11
Baochen Qiang <quic_bqiang@quicinc.com> writes:

>> Ok, I think I now get what you mean. Does this look better:
>> 
>> static void ath12k_mac_free_unassign_link_sta(struct ath12k_hw *ah,
>> 					      struct ath12k_sta *ahsta,
>> 					      u8 link_id)
>> {
>> 	struct ath12k_link_sta *arsta;
>> 
>> 	lockdep_assert_wiphy(ah->hw->wiphy);
>> 
>> 	if (WARN_ON(link_id >= IEEE80211_MLD_MAX_NUM_LINKS))
>> 		return;
>> 
>> 	arsta = wiphy_dereference(ah->hw->wiphy, ahsta->link[link_id]);
>> 	if (WARN_ON(!arsta))
>> 		return;
>> 
>> 	ahsta->links_map &= ~BIT(link_id);
>> 	rcu_assign_pointer(ahsta->link[link_id], NULL);
>
> below synchronize_rcu() should be moved to here, such that any change
> to arsta can happen only AFTER all existing RCU readers finish
> accessing it.

Good point, I'll move it.
diff mbox series

Patch

diff --git a/drivers/net/wireless/ath/ath12k/core.h b/drivers/net/wireless/ath/ath12k/core.h
index 8dbdf6818f58..46aabd66a83e 100644
--- a/drivers/net/wireless/ath/ath12k/core.h
+++ b/drivers/net/wireless/ath/ath12k/core.h
@@ -501,6 +501,8 @@  struct ath12k_link_sta {
 
 	 /* for firmware use only */
 	u8 link_idx;
+
+	enum ieee80211_sta_state state;
 };
 
 struct ath12k_sta {
@@ -510,7 +512,9 @@  struct ath12k_sta {
 	struct ath12k_link_sta __rcu *link[IEEE80211_MLD_MAX_NUM_LINKS];
 	/* indicates bitmap of link sta created in FW */
 	u16 links_map;
+	u8 assoc_link_id;
 	u16 ml_peer_id;
+	u8 num_peer;
 };
 
 #define ATH12K_MIN_5G_FREQ 4150
diff --git a/drivers/net/wireless/ath/ath12k/mac.c b/drivers/net/wireless/ath/ath12k/mac.c
index ad27a2552a2c..0ff886e4b3ed 100644
--- a/drivers/net/wireless/ath/ath12k/mac.c
+++ b/drivers/net/wireless/ath/ath12k/mac.c
@@ -254,6 +254,9 @@  static int ath12k_start_vdev_delay(struct ath12k *ar,
 static void ath12k_mac_stop(struct ath12k *ar);
 static int ath12k_mac_vdev_create(struct ath12k *ar, struct ath12k_link_vif *arvif);
 static int ath12k_mac_vdev_delete(struct ath12k *ar, struct ath12k_link_vif *arvif);
+static void ath12k_mac_free_unassign_link_sta(struct ath12k_hw *ah,
+					      struct ath12k_sta *ahsta,
+					      u8 link_id);
 
 static const char *ath12k_mac_phymode_str(enum wmi_phy_mode mode)
 {
@@ -1251,7 +1254,7 @@  static int ath12k_mac_monitor_stop(struct ath12k *ar)
 	return ret;
 }
 
-static int ath12k_mac_vdev_stop(struct ath12k_link_vif *arvif)
+int ath12k_mac_vdev_stop(struct ath12k_link_vif *arvif)
 {
 	struct ath12k_vif *ahvif = arvif->ahvif;
 	struct ath12k *ar = arvif->ar;
@@ -4871,7 +4874,6 @@  static void ath12k_mac_station_post_remove(struct ath12k *ar,
 {
 	struct ieee80211_vif *vif = ath12k_ahvif_to_vif(arvif->ahvif);
 	struct ieee80211_sta *sta = ath12k_ahsta_to_sta(arsta->ahsta);
-	struct ath12k_sta *ahsta = arsta->ahsta;
 	struct ath12k_peer *peer;
 
 	lockdep_assert_wiphy(ath12k_ar_to_hw(ar)->wiphy);
@@ -4894,14 +4896,6 @@  static void ath12k_mac_station_post_remove(struct ath12k *ar,
 
 	kfree(arsta->rx_stats);
 	arsta->rx_stats = NULL;
-
-	if (arsta->link_id < IEEE80211_MLD_MAX_NUM_LINKS) {
-		ahsta->links_map &= ~(BIT(arsta->link_id));
-		rcu_assign_pointer(ahsta->link[arsta->link_id], NULL);
-		synchronize_rcu();
-		arsta->link_id = ATH12K_INVALID_LINK_ID;
-		arsta->ahsta = NULL;
-	}
 }
 
 static int ath12k_mac_station_unauthorize(struct ath12k *ar,
@@ -5003,6 +4997,10 @@  static int ath12k_mac_station_remove(struct ath12k *ar,
 
 	ath12k_mac_station_post_remove(ar, arvif, arsta);
 
+	if (sta->valid_links)
+		ath12k_mac_free_unassign_link_sta(ahvif->ah,
+						  arsta->ahsta, arsta->link_id);
+
 	return ret;
 }
 
@@ -5114,20 +5112,137 @@  static u32 ath12k_mac_ieee80211_sta_bw_to_wmi(struct ath12k *ar,
 	return bw;
 }
 
+static int ath12k_mac_assign_link_sta(struct ath12k_hw *ah,
+				      struct ath12k_sta *ahsta,
+				      struct ath12k_link_sta *arsta,
+				      struct ath12k_vif *ahvif,
+				      u8 link_id)
+{
+	struct ieee80211_sta *sta = ath12k_ahsta_to_sta(ahsta);
+	struct ieee80211_link_sta *link_sta;
+	struct ath12k_link_vif *arvif;
+
+	lockdep_assert_wiphy(ah->hw->wiphy);
+
+	if (!arsta || link_id >= IEEE80211_MLD_MAX_NUM_LINKS)
+		return -EINVAL;
+
+	arvif = wiphy_dereference(ah->hw->wiphy, ahvif->link[link_id]);
+	if (!arvif)
+		return -EINVAL;
+
+	memset(arsta, 0, sizeof(*arsta));
+
+	link_sta = wiphy_dereference(ah->hw->wiphy, sta->link[link_id]);
+	if (!link_sta)
+		return -EINVAL;
+
+	ether_addr_copy(arsta->addr, link_sta->addr);
+
+	/* logical index of the link sta in order of creation */
+	arsta->link_idx = ahsta->num_peer++;
+
+	arsta->link_id = link_id;
+	ahsta->links_map |= BIT(arsta->link_id);
+	arsta->arvif = arvif;
+	arsta->ahsta = ahsta;
+	arsta->state = IEEE80211_STA_NONE;
+	wiphy_work_init(&arsta->update_wk, ath12k_sta_rc_update_wk);
+
+	rcu_assign_pointer(ahsta->link[link_id], arsta);
+
+	synchronize_rcu();
+
+	return 0;
+}
+
+static void ath12k_mac_unassign_link_sta(struct ath12k_hw *ah,
+					 struct ath12k_sta *ahsta,
+					 u8 link_id)
+{
+	lockdep_assert_wiphy(ah->hw->wiphy);
+
+	ahsta->links_map &= ~BIT(link_id);
+	rcu_assign_pointer(ahsta->link[link_id], NULL);
+
+	synchronize_rcu();
+}
+
+static void ath12k_mac_free_unassign_link_sta(struct ath12k_hw *ah,
+					      struct ath12k_sta *ahsta,
+					      u8 link_id)
+{
+	struct ath12k_link_sta *arsta;
+
+	lockdep_assert_wiphy(ah->hw->wiphy);
+
+	if (WARN_ON(link_id >= IEEE80211_MLD_MAX_NUM_LINKS))
+		return;
+
+	arsta = wiphy_dereference(ah->hw->wiphy, ahsta->link[link_id]);
+
+	if (WARN_ON(!arsta))
+		return;
+
+	ath12k_mac_unassign_link_sta(ah, ahsta, link_id);
+
+	arsta->link_id = ATH12K_INVALID_LINK_ID;
+	arsta->ahsta = NULL;
+	arsta->arvif = NULL;
+
+	if (arsta != &ahsta->deflink)
+		kfree(arsta);
+}
+
+static void ath12k_mac_ml_station_remove(struct ath12k_vif *ahvif,
+					 struct ath12k_sta *ahsta)
+{
+	struct ieee80211_sta *sta = ath12k_ahsta_to_sta(ahsta);
+	struct ath12k_hw *ah = ahvif->ah;
+	struct ath12k_link_vif *arvif;
+	struct ath12k_link_sta *arsta;
+	unsigned long links;
+	struct ath12k *ar;
+	u8 link_id;
+
+	lockdep_assert_wiphy(ah->hw->wiphy);
+
+	ath12k_peer_mlo_link_peers_delete(ahvif, ahsta);
+
+	/* validate link station removal and clear arsta links */
+	links = ahsta->links_map;
+	for_each_set_bit(link_id, &links, IEEE80211_MLD_MAX_NUM_LINKS) {
+		arvif = wiphy_dereference(ah->hw->wiphy, ahvif->link[link_id]);
+		arsta = wiphy_dereference(ah->hw->wiphy, ahsta->link[link_id]);
+		if (!arvif || !arsta)
+			continue;
+
+		ar = arvif->ar;
+
+		ath12k_mac_station_post_remove(ar, arvif, arsta);
+
+		ath12k_mac_free_unassign_link_sta(ah, ahsta, link_id);
+	}
+
+	ath12k_peer_ml_delete(ah, sta);
+}
+
 static int ath12k_mac_handle_link_sta_state(struct ieee80211_hw *hw,
 					    struct ath12k_link_vif *arvif,
 					    struct ath12k_link_sta *arsta,
 					    enum ieee80211_sta_state old_state,
 					    enum ieee80211_sta_state new_state)
 {
-	struct ath12k *ar = arvif->ar;
 	struct ieee80211_vif *vif = ath12k_ahvif_to_vif(arvif->ahvif);
 	struct ieee80211_sta *sta = ath12k_ahsta_to_sta(arsta->ahsta);
-	struct ath12k_sta *ahsta = arsta->ahsta;
+	struct ath12k *ar = arvif->ar;
 	int ret = 0;
 
 	lockdep_assert_wiphy(hw->wiphy);
 
+	ath12k_dbg(ar->ab, ATH12K_DBG_MAC, "mac handle link %u sta %pM state %d -> %d\n",
+		   arsta->link_id, arsta->addr, old_state, new_state);
+
 	/* IEEE80211_STA_NONE -> IEEE80211_STA_NOTEXIST: Remove the station
 	 * from driver
 	 */
@@ -5141,24 +5256,13 @@  static int ath12k_mac_handle_link_sta_state(struct ieee80211_hw *hw,
 		if (ret) {
 			ath12k_warn(ar->ab, "Failed to remove station: %pM for VDEV: %d\n",
 				    arsta->addr, arvif->vdev_id);
+			goto exit;
 		}
 	}
 
 	/* IEEE80211_STA_NOTEXIST -> IEEE80211_STA_NONE: Add new station to driver */
 	if (old_state == IEEE80211_STA_NOTEXIST &&
 	    new_state == IEEE80211_STA_NONE) {
-		memset(arsta, 0, sizeof(*arsta));
-		rcu_assign_pointer(ahsta->link[0], arsta);
-		/* TODO use appropriate link id once MLO support is added  */
-		arsta->link_id = ATH12K_DEFAULT_LINK_ID;
-		ahsta->links_map = BIT(arsta->link_id);
-		arsta->ahsta = ahsta;
-		arsta->arvif = arvif;
-		ether_addr_copy(arsta->addr, sta->addr);
-		wiphy_work_init(&arsta->update_wk, ath12k_sta_rc_update_wk);
-
-		synchronize_rcu();
-
 		ret = ath12k_mac_station_add(ar, arvif, arsta);
 		if (ret)
 			ath12k_warn(ar->ab, "Failed to add station: %pM for VDEV: %d\n",
@@ -5200,6 +5304,7 @@  static int ath12k_mac_handle_link_sta_state(struct ieee80211_hw *hw,
 	} else if (old_state == IEEE80211_STA_AUTHORIZED &&
 		   new_state == IEEE80211_STA_ASSOC) {
 		ath12k_mac_station_unauthorize(ar, arvif, arsta);
+
 	/* IEEE80211_STA_ASSOC -> IEEE80211_STA_AUTH: disassoc peer connected to
 	 * AP/mesh/ADHOC vif type.
 	 */
@@ -5214,6 +5319,9 @@  static int ath12k_mac_handle_link_sta_state(struct ieee80211_hw *hw,
 				    sta->addr);
 	}
 
+exit:
+	arsta->state = new_state;
+
 	return ret;
 }
 
@@ -5225,10 +5333,12 @@  static int ath12k_mac_op_sta_state(struct ieee80211_hw *hw,
 {
 	struct ath12k_vif *ahvif = ath12k_vif_to_ahvif(vif);
 	struct ath12k_sta *ahsta = ath12k_sta_to_ahsta(sta);
+	struct ath12k_hw *ah = ath12k_hw_to_ah(hw);
 	struct ath12k_link_vif *arvif;
 	struct ath12k_link_sta *arsta;
-	int ret;
+	unsigned long valid_links;
 	u8 link_id = 0;
+	int ret;
 
 	lockdep_assert_wiphy(hw->wiphy);
 
@@ -5237,27 +5347,78 @@  static int ath12k_mac_op_sta_state(struct ieee80211_hw *hw,
 		link_id = ffs(sta->valid_links) - 1;
 	}
 
-	/* Handle for non-ML station */
-	if (!sta->mlo) {
-		arvif = wiphy_dereference(hw->wiphy, ahvif->link[link_id]);
-		arsta = &ahsta->deflink;
-		arsta->ahsta = ahsta;
+	/* IEEE80211_STA_NOTEXIST -> IEEE80211_STA_NONE:
+	 * New station add received. If this is a ML station then
+	 * ahsta->links_map will be zero and sta->valid_links will be 1.
+	 * Assign default link to the first link sta.
+	 */
+	if (old_state == IEEE80211_STA_NOTEXIST &&
+	    new_state == IEEE80211_STA_NONE) {
+		memset(ahsta, 0, sizeof(*ahsta));
 
-		if (WARN_ON(!arvif || !arsta)) {
-			ret = -EINVAL;
+		arsta = &ahsta->deflink;
+
+		/* ML sta */
+		if (sta->mlo && !ahsta->links_map &&
+		    (hweight16(sta->valid_links) == 1)) {
+			ret = ath12k_peer_ml_create(ah, sta);
+			if (ret) {
+				ath12k_hw_warn(ah, "unable to create ML peer for sta %pM",
+					       sta->addr);
+				goto exit;
+			}
+		}
+
+		ret = ath12k_mac_assign_link_sta(ah, ahsta, arsta, ahvif,
+						 link_id);
+		if (ret) {
+			ath12k_hw_warn(ah, "unable assign link %d for sta %pM",
+				       link_id, sta->addr);
 			goto exit;
 		}
 
+		/* above arsta will get memset, hence do this after assign
+		 * link sta
+		 */
+		if (sta->mlo) {
+			arsta->is_assoc_link = true;
+			ahsta->assoc_link_id = link_id;
+		}
+	}
+
+	/* IEEE80211_STA_NONE -> IEEE80211_STA_NOTEXIST:
+	 * Remove the station from driver (handle ML sta here since that
+	 * needs special handling. Normal sta will be handled in generic
+	 * handler below
+	 */
+	if (old_state == IEEE80211_STA_NONE &&
+	    new_state == IEEE80211_STA_NOTEXIST &&
+	    sta->mlo) {
+		ath12k_mac_ml_station_remove(ahvif, ahsta);
+		/* nothing left to do */
+		goto exit;
+	}
+
+	/* Handle all the other state transitions in generic way */
+	valid_links = ahsta->links_map;
+	for_each_set_bit(link_id, &valid_links, IEEE80211_MLD_MAX_NUM_LINKS) {
+		arvif = wiphy_dereference(hw->wiphy, ahvif->link[link_id]);
+		arsta = wiphy_dereference(hw->wiphy, ahsta->link[link_id]);
+		/* some assumptions went wrong! */
+		if (WARN_ON(!arvif || !arsta))
+			continue;
+
 		/* vdev might be in deleted */
-		if (WARN_ON(!arvif->ar)) {
-			ret = -EINVAL;
-			goto exit;
-		}
+		if (WARN_ON(!arvif->ar))
+			continue;
 
 		ret = ath12k_mac_handle_link_sta_state(hw, arvif, arsta,
 						       old_state, new_state);
-		if (ret)
+		if (ret) {
+			ath12k_hw_warn(ah, "unable to move link sta %d of sta %pM from state %d to %d",
+				       link_id, arsta->addr, old_state, new_state);
 			goto exit;
+		}
 	}
 
 	ret = 0;
diff --git a/drivers/net/wireless/ath/ath12k/mac.h b/drivers/net/wireless/ath/ath12k/mac.h
index d382337ba649..c13630ee479a 100644
--- a/drivers/net/wireless/ath/ath12k/mac.h
+++ b/drivers/net/wireless/ath/ath12k/mac.h
@@ -89,5 +89,6 @@  int ath12k_mac_vif_set_keepalive(struct ath12k_link_vif *arvif,
 				 enum wmi_sta_keepalive_method method,
 				 u32 interval);
 u8 ath12k_mac_get_target_pdev_id(struct ath12k *ar);
+int ath12k_mac_vdev_stop(struct ath12k_link_vif *arvif);
 
 #endif
diff --git a/drivers/net/wireless/ath/ath12k/peer.c b/drivers/net/wireless/ath/ath12k/peer.c
index 0e86847edd6e..50e0d3d90bf6 100644
--- a/drivers/net/wireless/ath/ath12k/peer.c
+++ b/drivers/net/wireless/ath/ath12k/peer.c
@@ -264,8 +264,9 @@  int ath12k_wait_for_peer_delete_done(struct ath12k *ar, u32 vdev_id,
 	return 0;
 }
 
-int ath12k_peer_delete(struct ath12k *ar, u32 vdev_id, u8 *addr)
+static int ath12k_peer_delete_send(struct ath12k *ar, u32 vdev_id, const u8 *addr)
 {
+	struct ath12k_base *ab = ar->ab;
 	int ret;
 
 	lockdep_assert_wiphy(ath12k_ar_to_hw(ar)->wiphy);
@@ -274,12 +275,25 @@  int ath12k_peer_delete(struct ath12k *ar, u32 vdev_id, u8 *addr)
 
 	ret = ath12k_wmi_send_peer_delete_cmd(ar, addr, vdev_id);
 	if (ret) {
-		ath12k_warn(ar->ab,
+		ath12k_warn(ab,
 			    "failed to delete peer vdev_id %d addr %pM ret %d\n",
 			    vdev_id, addr, ret);
 		return ret;
 	}
 
+	return 0;
+}
+
+int ath12k_peer_delete(struct ath12k *ar, u32 vdev_id, u8 *addr)
+{
+	int ret;
+
+	lockdep_assert_wiphy(ath12k_ar_to_hw(ar)->wiphy);
+
+	ret = ath12k_peer_delete_send(ar, vdev_id, addr);
+	if (ret)
+		return ret;
+
 	ret = ath12k_wait_for_peer_delete_done(ar, vdev_id, addr);
 	if (ret)
 		return ret;
@@ -456,3 +470,77 @@  int ath12k_peer_ml_delete(struct ath12k_hw *ah, struct ieee80211_sta *sta)
 
 	return 0;
 }
+
+int ath12k_peer_mlo_link_peers_delete(struct ath12k_vif *ahvif, struct ath12k_sta *ahsta)
+{
+	struct ieee80211_sta *sta = ath12k_ahsta_to_sta(ahsta);
+	struct ath12k_hw *ah = ahvif->ah;
+	struct ath12k_link_vif *arvif;
+	struct ath12k_link_sta *arsta;
+	unsigned long links;
+	struct ath12k *ar;
+	int ret, err_ret = 0;
+	u8 link_id;
+
+	lockdep_assert_wiphy(ah->hw->wiphy);
+
+	if (!sta->mlo)
+		return -EINVAL;
+
+	/* FW expects delete of all link peers at once before waiting for reception
+	 * of peer unmap or delete responses
+	 */
+	links = ahsta->links_map;
+	for_each_set_bit(link_id, &links, IEEE80211_MLD_MAX_NUM_LINKS) {
+		arvif = wiphy_dereference(ah->hw->wiphy, ahvif->link[link_id]);
+		arsta = wiphy_dereference(ah->hw->wiphy, ahsta->link[link_id]);
+		if (!arvif || !arsta)
+			continue;
+
+		ar = arvif->ar;
+		if (!ar)
+			continue;
+
+		wiphy_work_cancel(ath12k_ar_to_hw(ar)->wiphy, &arsta->update_wk);
+
+		if (ahvif->vdev_type == WMI_VDEV_TYPE_STA) {
+			ret = ath12k_mac_vdev_stop(arvif);
+			if (ret)
+				ath12k_warn(ar->ab, "failed to stop vdev %i: %d\n",
+					    arvif->vdev_id, ret);
+		}
+
+		ath12k_dp_peer_cleanup(ar, arvif->vdev_id, arsta->addr);
+
+		ret = ath12k_peer_delete_send(ar, arvif->vdev_id, arsta->addr);
+		if (ret) {
+			ath12k_warn(ar->ab,
+				    "failed to delete peer vdev_id %d addr %pM ret %d\n",
+				    arvif->vdev_id, arsta->addr, ret);
+			err_ret = ret;
+			continue;
+		}
+	}
+
+	/* Ensure all link peers are deleted and unmapped */
+	links = ahsta->links_map;
+	for_each_set_bit(link_id, &links, IEEE80211_MLD_MAX_NUM_LINKS) {
+		arvif = wiphy_dereference(ah->hw->wiphy, ahvif->link[link_id]);
+		arsta = wiphy_dereference(ah->hw->wiphy, ahsta->link[link_id]);
+		if (!arvif || !arsta)
+			continue;
+
+		ar = arvif->ar;
+		if (!ar)
+			continue;
+
+		ret = ath12k_wait_for_peer_delete_done(ar, arvif->vdev_id, arsta->addr);
+		if (ret) {
+			err_ret = ret;
+			continue;
+		}
+		ar->num_peers--;
+	}
+
+	return err_ret;
+}
diff --git a/drivers/net/wireless/ath/ath12k/peer.h b/drivers/net/wireless/ath/ath12k/peer.h
index c28aca5d88a0..e398d5a3fdc8 100644
--- a/drivers/net/wireless/ath/ath12k/peer.h
+++ b/drivers/net/wireless/ath/ath12k/peer.h
@@ -78,5 +78,6 @@  bool ath12k_peer_exist_by_vdev_id(struct ath12k_base *ab, int vdev_id);
 struct ath12k_peer *ath12k_peer_find_by_ast(struct ath12k_base *ab, int ast_hash);
 int ath12k_peer_ml_create(struct ath12k_hw *ah, struct ieee80211_sta *sta);
 int ath12k_peer_ml_delete(struct ath12k_hw *ah, struct ieee80211_sta *sta);
+int ath12k_peer_mlo_link_peers_delete(struct ath12k_vif *ahvif, struct ath12k_sta *ahsta);
 
 #endif /* _PEER_H_ */