iwlwifi: mvm: add low-latency framework

For various traffic use cases, we want to be able to treat multi-
channel scenarios differently. Introduce a low-latency framework
that currently only has a debugfs file to enable low-latency mode,
but can later be extended.

Signed-off-by: Johannes Berg <johannes.berg@intel.com>
Signed-off-by: Emmanuel Grumbach <emmanuel.grumbach@intel.com>

3 files changed, 74 insertions, 1 deletions

diff --git a/drivers/net/wireless/iwlwifi/mvm/debugfs-vif.c b/drivers/net/wireless/iwlwifi/mvm/debugfs-vif.c
index 0e29cd83a06a..19ecade5ec5f 100644
--- a/drivers/net/wireless/iwlwifi/mvm/debugfs-vif.c
+++ b/drivers/net/wireless/iwlwifi/mvm/debugfs-vif.c
@@ -460,6 +460,41 @@ static ssize_t iwl_dbgfs_bf_params_read(struct file *file,
         return simple_read_from_buffer(user_buf, count, ppos, buf, pos);
 }
 
+static ssize_t iwl_dbgfs_low_latency_write(struct ieee80211_vif *vif, char *buf,
+                                           size_t count, loff_t *ppos)
+{
+        struct iwl_mvm_vif *mvmvif = iwl_mvm_vif_from_mac80211(vif);
+        struct iwl_mvm *mvm = mvmvif->mvm;
+        u8 value;
+        int ret;
+
+        ret = kstrtou8(buf, 0, &value);
+        if (ret)
+                return ret;
+        if (value > 1)
+                return -EINVAL;
+
+        mutex_lock(&mvm->mutex);
+        iwl_mvm_update_low_latency(mvm, vif, value);
+        mutex_unlock(&mvm->mutex);
+
+        return count;
+}
+
+static ssize_t iwl_dbgfs_low_latency_read(struct file *file,
+                                          char __user *user_buf,
+                                          size_t count, loff_t *ppos)
+{
+        struct ieee80211_vif *vif = file->private_data;
+        struct iwl_mvm_vif *mvmvif = iwl_mvm_vif_from_mac80211(vif);
+        char buf[3];
+
+        buf[0] = mvmvif->low_latency ? '1' : '0';
+        buf[1] = '\n';
+        buf[2] = '\0';
+        return simple_read_from_buffer(user_buf, count, ppos, buf, sizeof(buf));
+}
+
 #define MVM_DEBUGFS_WRITE_FILE_OPS(name, bufsz) \
         _MVM_DEBUGFS_WRITE_FILE_OPS(name, bufsz, struct ieee80211_vif)
 #define MVM_DEBUGFS_READ_WRITE_FILE_OPS(name, bufsz) \
@@ -473,6 +508,7 @@ static ssize_t iwl_dbgfs_bf_params_read(struct file *file,
 MVM_DEBUGFS_READ_FILE_OPS(mac_params);
 MVM_DEBUGFS_READ_WRITE_FILE_OPS(pm_params, 32);
 MVM_DEBUGFS_READ_WRITE_FILE_OPS(bf_params, 256);
+MVM_DEBUGFS_READ_WRITE_FILE_OPS(low_latency, 10);
 
 void iwl_mvm_vif_dbgfs_register(struct iwl_mvm *mvm, struct ieee80211_vif *vif)
 {
@@ -505,6 +541,8 @@ void iwl_mvm_vif_dbgfs_register(struct iwl_mvm *mvm, struct ieee80211_vif *vif)
 
         MVM_DEBUGFS_ADD_FILE_VIF(mac_params, mvmvif->dbgfs_dir,
                                  S_IRUSR);
+        MVM_DEBUGFS_ADD_FILE_VIF(low_latency, mvmvif->dbgfs_dir,
+                                 S_IRUSR | S_IWUSR);
 
         if (vif->type == NL80211_IFTYPE_STATION && !vif->p2p &&
             mvmvif == mvm->bf_allowed_vif)
diff --git a/drivers/net/wireless/iwlwifi/mvm/mvm.h b/drivers/net/wireless/iwlwifi/mvm/mvm.h
index 02e4bdc80de2..00bc4ce06cca 100644
--- a/drivers/net/wireless/iwlwifi/mvm/mvm.h
+++ b/drivers/net/wireless/iwlwifi/mvm/mvm.h
@@ -269,7 +269,9 @@ struct iwl_mvm_vif_bf_data {
  * @ap_ibss_active: indicates that AP/IBSS is configured and that the interface
  *      should get quota etc.
  * @monitor_active: indicates that monitor context is configured, and that the
- * interface should get quota etc.
+ *      interface should get quota etc.
+ * @low_latency: indicates that this interface is in low-latency mode
+ *      (VMACLowLatencyMode)
  * @queue_params: QoS params for this MAC
  * @bcast_sta: station used for broadcast packets. Used by the following
  *  vifs: P2P_DEVICE, GO and AP.
@@ -285,6 +287,7 @@ struct iwl_mvm_vif {
         bool uploaded;
         bool ap_ibss_active;
         bool monitor_active;
+        bool low_latency;
         struct iwl_mvm_vif_bf_data bf_data;
 
         u32 ap_beacon_time;
@@ -909,6 +912,26 @@ void iwl_mvm_update_smps(struct iwl_mvm *mvm, struct ieee80211_vif *vif,
                                 enum iwl_mvm_smps_type_request req_type,
                                 enum ieee80211_smps_mode smps_request);
 
+/* Low latency */
+int iwl_mvm_update_low_latency(struct iwl_mvm *mvm, struct ieee80211_vif *vif,
+                               bool value);
+/* get VMACLowLatencyMode */
+static inline bool iwl_mvm_vif_low_latency(struct iwl_mvm_vif *mvmvif)
+{
+        /*
+         * should this consider associated/active/... state?
+         *
+         * Normally low-latency should only be active on interfaces
+         * that are active, but at least with debugfs it can also be
+         * enabled on interfaces that aren't active. However, when
+         * interface aren't active then they aren't added into the
+         * binding, so this has no real impact. For now, just return
+         * the current desired low-latency state.
+         */
+
+        return mvmvif->low_latency;
+}
+
 /* Thermal management and CT-kill */
 void iwl_mvm_tt_handler(struct iwl_mvm *mvm);
 void iwl_mvm_tt_initialize(struct iwl_mvm *mvm);
diff --git a/drivers/net/wireless/iwlwifi/mvm/utils.c b/drivers/net/wireless/iwlwifi/mvm/utils.c
index a4a5e25623c3..e2cc876d9388 100644
--- a/drivers/net/wireless/iwlwifi/mvm/utils.c
+++ b/drivers/net/wireless/iwlwifi/mvm/utils.c
@@ -536,3 +536,15 @@ void iwl_mvm_update_smps(struct iwl_mvm *mvm, struct ieee80211_vif *vif,
 
         ieee80211_request_smps(vif, smps_mode);
 }
+
+int iwl_mvm_update_low_latency(struct iwl_mvm *mvm, struct ieee80211_vif *vif,
+                               bool value)
+{
+        struct iwl_mvm_vif *mvmvif = iwl_mvm_vif_from_mac80211(vif);
+
+        lockdep_assert_held(&mvm->mutex);
+
+        mvmvif->low_latency = value;
+
+        return iwl_mvm_update_quotas(mvm, NULL);
+}