iwlwifi: mvm: support setting minimum quota from debugfs

For debug purposes, allow setting minimum quota (for a single
virtual interface) from debugfs. This is an absolute minimum,
so it can only be set up to 95%.

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

3 files changed, 73 insertions, 0 deletions

diff --git a/drivers/net/wireless/intel/iwlwifi/mvm/debugfs-vif.c b/drivers/net/wireless/intel/iwlwifi/mvm/debugfs-vif.c
index c286a5f8d8bd..14004456bf55 100644
--- a/drivers/net/wireless/intel/iwlwifi/mvm/debugfs-vif.c
+++ b/drivers/net/wireless/intel/iwlwifi/mvm/debugfs-vif.c
@@ -1372,6 +1372,59 @@ static ssize_t iwl_dbgfs_rx_phyinfo_read(struct file *file,
         return simple_read_from_buffer(user_buf, count, ppos, buf, sizeof(buf));
 }
 
+static void iwl_dbgfs_quota_check(void *data, u8 *mac,
+                                  struct ieee80211_vif *vif)
+{
+        struct iwl_mvm_vif *mvmvif = iwl_mvm_vif_from_mac80211(vif);
+        int *ret = data;
+
+        if (mvmvif->dbgfs_quota_min)
+                *ret = -EINVAL;
+}
+
+static ssize_t iwl_dbgfs_quota_min_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;
+        u16 value;
+        int ret;
+
+        ret = kstrtou16(buf, 0, &value);
+        if (ret)
+                return ret;
+
+        if (value > 95)
+                return -EINVAL;
+
+        mutex_lock(&mvm->mutex);
+
+        mvmvif->dbgfs_quota_min = 0;
+        ieee80211_iterate_interfaces(mvm->hw, IEEE80211_IFACE_ITER_NORMAL,
+                                     iwl_dbgfs_quota_check, &ret);
+        if (ret == 0) {
+                mvmvif->dbgfs_quota_min = value;
+                iwl_mvm_update_quotas(mvm, false, NULL);
+        }
+        mutex_unlock(&mvm->mutex);
+
+        return ret ?: count;
+}
+
+static ssize_t iwl_dbgfs_quota_min_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[10];
+        int len;
+
+        len = snprintf(buf, sizeof(buf), "%d\n", mvmvif->dbgfs_quota_min);
+
+        return simple_read_from_buffer(user_buf, count, ppos, buf, len);
+}
+
 #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) \
@@ -1395,6 +1448,7 @@ MVM_DEBUGFS_READ_WRITE_FILE_OPS(tof_range_req_ext, 32);
 MVM_DEBUGFS_READ_WRITE_FILE_OPS(tof_range_abort, 32);
 MVM_DEBUGFS_READ_FILE_OPS(tof_range_response);
 MVM_DEBUGFS_READ_WRITE_FILE_OPS(tof_responder_params, 32);
+MVM_DEBUGFS_READ_WRITE_FILE_OPS(quota_min, 32);
 
 void iwl_mvm_vif_dbgfs_register(struct iwl_mvm *mvm, struct ieee80211_vif *vif)
 {
@@ -1432,6 +1486,8 @@ void iwl_mvm_vif_dbgfs_register(struct iwl_mvm *mvm, struct ieee80211_vif *vif)
                                  S_IRUSR | S_IWUSR);
         MVM_DEBUGFS_ADD_FILE_VIF(rx_phyinfo, mvmvif->dbgfs_dir,
                                  S_IRUSR | S_IWUSR);
+        MVM_DEBUGFS_ADD_FILE_VIF(quota_min, 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/intel/iwlwifi/mvm/mvm.h b/drivers/net/wireless/intel/iwlwifi/mvm/mvm.h
index 418aeffd9bab..5a34808fdeed 100644
--- a/drivers/net/wireless/intel/iwlwifi/mvm/mvm.h
+++ b/drivers/net/wireless/intel/iwlwifi/mvm/mvm.h
@@ -433,6 +433,7 @@ struct iwl_mvm_vif {
         struct iwl_dbgfs_pm dbgfs_pm;
         struct iwl_dbgfs_bf dbgfs_bf;
         struct iwl_mac_power_cmd mac_pwr_cmd;
+        int dbgfs_quota_min;
 #endif
 
         enum ieee80211_smps_mode smps_requests[NUM_IWL_MVM_SMPS_REQ];
diff --git a/drivers/net/wireless/intel/iwlwifi/mvm/quota.c b/drivers/net/wireless/intel/iwlwifi/mvm/quota.c
index 0b762b4f8fad..2141db5bff82 100644
--- a/drivers/net/wireless/intel/iwlwifi/mvm/quota.c
+++ b/drivers/net/wireless/intel/iwlwifi/mvm/quota.c
@@ -7,6 +7,7 @@
  *
  * Copyright(c) 2012 - 2014 Intel Corporation. All rights reserved.
  * Copyright(c) 2013 - 2014 Intel Mobile Communications GmbH
+ * Copyright(c) 2016        Intel Deutschland GmbH
  *
  * This program is free software; you can redistribute it and/or modify
  * it under the terms of version 2 of the GNU General Public License as
@@ -33,6 +34,7 @@
  *
  * Copyright(c) 2012 - 2014 Intel Corporation. All rights reserved.
  * Copyright(c) 2013 - 2014 Intel Mobile Communications GmbH
+ * Copyright(c) 2016        Intel Deutschland GmbH
  * All rights reserved.
  *
  * Redistribution and use in source and binary forms, with or without
@@ -74,6 +76,9 @@ struct iwl_mvm_quota_iterator_data {
         int n_interfaces[MAX_BINDINGS];
         int colors[MAX_BINDINGS];
         int low_latency[MAX_BINDINGS];
+#ifdef CONFIG_IWLWIFI_DEBUGFS
+        int dbgfs_min[MAX_BINDINGS];
+#endif
         int n_low_latency_bindings;
         struct ieee80211_vif *disabled_vif;
 };
@@ -129,6 +134,12 @@ static void iwl_mvm_quota_iterator(void *_data, u8 *mac,
 
         data->n_interfaces[id]++;
 
+#ifdef CONFIG_IWLWIFI_DEBUGFS
+        if (mvmvif->dbgfs_quota_min)
+                data->dbgfs_min[id] = max(data->dbgfs_min[id],
+                                          mvmvif->dbgfs_quota_min);
+#endif
+
         if (iwl_mvm_vif_low_latency(mvmvif) && !data->low_latency[id]) {
                 data->n_low_latency_bindings++;
                 data->low_latency[id] = true;
@@ -259,6 +270,11 @@ int iwl_mvm_update_quotas(struct iwl_mvm *mvm,
 
                 if (data.n_interfaces[i] <= 0)
                         cmd.quotas[idx].quota = cpu_to_le32(0);
+#ifdef CONFIG_IWLWIFI_DEBUGFS
+                else if (data.dbgfs_min[i])
+                        cmd.quotas[idx].quota =
+                                cpu_to_le32(data.dbgfs_min[i] * QUOTA_100 / 100);
+#endif
                 else if (data.n_low_latency_bindings == 1 && n_non_lowlat &&
                          data.low_latency[i])
                         /*