iwlwifi: mvm: add debugfs to trigger fw debug logs collection

This allows to collect the logs even if the firmware hasn't
crashed. Of course, crashing the firmware is an option, but
this is easier and nicer.

Signed-off-by: Emmanuel Grumbach <emmanuel.grumbach@intel.com>

drivers/net/wireless/iwlwifi/iwl-prph.h

@@ -366,11 +366,15 @@ enum secure_load_status_reg {
 #define RXF_FIFO_RD_FENCE_ADDR		(0xa00c0c)
 
 /* FW monitor */
+#define MON_BUFF_SAMPLE_CTL		(0xa03c00)
 #define MON_BUFF_BASE_ADDR		(0xa03c3c)
 #define MON_BUFF_END_ADDR		(0xa03c40)
 #define MON_BUFF_WRPTR			(0xa03c44)
 #define MON_BUFF_CYCLE_CNT		(0xa03c48)
 
+#define DBGC_IN_SAMPLE			(0xa03c00)
+#define DBGC_OUT_CTRL			(0xa03c0c)
+
 /* FW chicken bits */
 #define LMPM_CHICK			0xA01FF8
 enum {

drivers/net/wireless/iwlwifi/mvm/debugfs.c

@@ -945,6 +945,56 @@ iwl_dbgfs_scan_ant_rxchain_write(struct iwl_mvm *mvm, char *buf,
 	return count;
 }
 
+static ssize_t iwl_dbgfs_fw_dbg_conf_read(struct file *file,
+					  char __user *user_buf,
+					  size_t count, loff_t *ppos)
+{
+	struct iwl_mvm *mvm = file->private_data;
+	enum iwl_fw_dbg_conf conf;
+	char buf[8];
+	const size_t bufsz = sizeof(buf);
+	int pos = 0;
+
+	mutex_lock(&mvm->mutex);
+	conf = mvm->fw_dbg_conf;
+	mutex_unlock(&mvm->mutex);
+
+	pos += scnprintf(buf + pos, bufsz - pos, "%d\n", conf);
+
+	return simple_read_from_buffer(user_buf, count, ppos, buf, pos);
+}
+
+static ssize_t iwl_dbgfs_fw_dbg_conf_write(struct iwl_mvm *mvm,
+					   char *buf, size_t count,
+					   loff_t *ppos)
+{
+	int ret, conf_id;
+
+	ret = kstrtoint(buf, 0, &conf_id);
+	if (ret)
+		return ret;
+
+	if (WARN_ON(conf_id >= FW_DBG_MAX))
+		return -EINVAL;
+
+	mutex_lock(&mvm->mutex);
+	ret = iwl_mvm_start_fw_dbg_conf(mvm, conf_id);
+	mutex_unlock(&mvm->mutex);
+
+	return ret ?: count;
+}
+
+static ssize_t iwl_dbgfs_fw_dbg_collect_write(struct iwl_mvm *mvm,
+					      char *buf, size_t count,
+					      loff_t *ppos)
+{
+	mutex_lock(&mvm->mutex);
+	iwl_mvm_fw_dbg_collect(mvm);
+	mutex_unlock(&mvm->mutex);
+
+	return count;
+}
+
 #define ADD_TEXT(...) pos += scnprintf(buf + pos, bufsz - pos, __VA_ARGS__)
 #ifdef CONFIG_IWLWIFI_BCAST_FILTERING
 static ssize_t iwl_dbgfs_bcast_filters_read(struct file *file,
@@ -1459,6 +1509,8 @@ MVM_DEBUGFS_WRITE_FILE_OPS(bt_tx_prio, 10);
 MVM_DEBUGFS_WRITE_FILE_OPS(bt_force_ant, 10);
 MVM_DEBUGFS_READ_WRITE_FILE_OPS(scan_ant_rxchain, 8);
 MVM_DEBUGFS_READ_WRITE_FILE_OPS(d0i3_refs, 8);
+MVM_DEBUGFS_READ_WRITE_FILE_OPS(fw_dbg_conf, 8);
+MVM_DEBUGFS_WRITE_FILE_OPS(fw_dbg_collect, 8);
 
 #ifdef CONFIG_IWLWIFI_BCAST_FILTERING
 MVM_DEBUGFS_READ_WRITE_FILE_OPS(bcast_filters, 256);
@@ -1500,6 +1552,8 @@ int iwl_mvm_dbgfs_register(struct iwl_mvm *mvm, struct dentry *dbgfs_dir)
 			     S_IWUSR | S_IRUSR);
 	MVM_DEBUGFS_ADD_FILE(prph_reg, mvm->debugfs_dir, S_IWUSR | S_IRUSR);
 	MVM_DEBUGFS_ADD_FILE(d0i3_refs, mvm->debugfs_dir, S_IRUSR | S_IWUSR);
+	MVM_DEBUGFS_ADD_FILE(fw_dbg_conf, mvm->debugfs_dir, S_IRUSR | S_IWUSR);
+	MVM_DEBUGFS_ADD_FILE(fw_dbg_collect, mvm->debugfs_dir, S_IWUSR);
 
 #ifdef CONFIG_IWLWIFI_BCAST_FILTERING
 	if (mvm->fw->ucode_capa.flags & IWL_UCODE_TLV_FLAGS_BCAST_FILTERING) {

drivers/net/wireless/iwlwifi/mvm/fw.c

@@ -70,6 +70,7 @@
 #include "iwl-debug.h"
 #include "iwl-csr.h" /* for iwl_mvm_rx_card_state_notif */
 #include "iwl-io.h" /* for iwl_mvm_rx_card_state_notif */
+#include "iwl-prph.h"
 #include "iwl-eeprom-parse.h"
 
 #include "mvm.h"
@@ -399,8 +400,26 @@ int iwl_run_init_mvm_ucode(struct iwl_mvm *mvm, bool read_nvm)
 	return ret;
 }
 
-static int iwl_mvm_start_fw_dbg_conf(struct iwl_mvm *mvm,
-				     enum iwl_fw_dbg_conf conf_id)
+void iwl_mvm_fw_dbg_collect(struct iwl_mvm *mvm)
+{
+	lockdep_assert_held(&mvm->mutex);
+
+	/* stop recording */
+	if (mvm->cfg->device_family == IWL_DEVICE_FAMILY_7000) {
+		iwl_set_bits_prph(mvm->trans, MON_BUFF_SAMPLE_CTL, 0x100);
+	} else {
+		iwl_write_prph(mvm->trans, DBGC_IN_SAMPLE, 0);
+		iwl_write_prph(mvm->trans, DBGC_OUT_CTRL, 0);
+	}
+
+	iwl_mvm_fw_error_dump(mvm);
+
+	/* start recording again */
+	WARN_ON_ONCE(mvm->fw->dbg_dest_tlv &&
+		     iwl_mvm_start_fw_dbg_conf(mvm, mvm->fw_dbg_conf));
+}
+
+int iwl_mvm_start_fw_dbg_conf(struct iwl_mvm *mvm, enum iwl_fw_dbg_conf conf_id)
 {
 	u8 *ptr;
 	int ret;

drivers/net/wireless/iwlwifi/mvm/mvm.h

@@ -1371,4 +1371,7 @@ struct ieee80211_vif *iwl_mvm_get_bss_vif(struct iwl_mvm *mvm);
 void iwl_mvm_nic_restart(struct iwl_mvm *mvm, bool fw_error);
 void iwl_mvm_fw_error_dump(struct iwl_mvm *mvm);
 
+int iwl_mvm_start_fw_dbg_conf(struct iwl_mvm *mvm, enum iwl_fw_dbg_conf id);
+void iwl_mvm_fw_dbg_collect(struct iwl_mvm *mvm);
+
 #endif /* __IWL_MVM_H__ */