[RFC] trace-cmd: plugin_mac80211: add parsing for the new drv_switch_vif_chanctx

[Luca Coelho <luca@coelho.fi>]

From: Luciano Coelho <luciano.coelho@intel.com>

This new command has a complex trace, with a variable number of struct
elements in an array and needs special parsing.  Add a parsing
function to handle it.

Signed-off-by: Luciano Coelho <luciano.coelho@intel.com>
---
 I'm sending this to linux-wireless as an RFC before sending it to
Steven to get some comments and because the new function hasn't yet
gotten to linux-wireless/mainline.

 plugin_mac80211.c | 93 +++++++++++++++++++++++++++++++++++++++++++++++++++++++
 1 file changed, 93 insertions(+)

diff --git a/plugin_mac80211.c b/plugin_mac80211.c
index f35cb80..0b4835e 100644
--- a/plugin_mac80211.c
+++ b/plugin_mac80211.c
@@ -191,12 +191,105 @@ static int drv_config(struct trace_seq *s, struct pevent_record *record,
 	return 0;
 }
 
+struct trace_vif_entry {
+	int vif_type;
+	bool p2p;
+	char vif_name[8];
+} __attribute__((packed));
+
+struct trace_chandef_entry {
+	unsigned int control_freq;
+	unsigned int chan_width;
+	unsigned int center_freq1;
+	unsigned int center_freq2;
+} __attribute__((packed));
+
+struct trace_switch_entry {
+	struct trace_vif_entry vif;
+	struct trace_chandef_entry old_chandef;
+	struct trace_chandef_entry new_chandef;
+} __attribute__((packed));
+
+static int drv_switch_vif_chanctx(struct trace_seq *s,
+				  struct pevent_record *record,
+				  struct event_format *event, void *context)
+{
+	struct format_field *f = pevent_find_field(event, "n_vifs");
+	unsigned int i, offset, len;
+	long long unsigned int n_vifs;
+	void *data = record->data;
+	struct trace_switch_entry *vifs;
+
+	if (!f) {
+		trace_seq_printf(s, "NOTFOUND: n_vifs");
+		return 0;
+	}
+
+	if (pevent_read_number_field(f, data, &n_vifs)) {
+		trace_seq_puts(s, "field-invalid: n_vifs");
+		return 0;
+	}
+
+	f = pevent_find_field(event, "vifs");
+
+	if (!f) {
+		trace_seq_printf(s, "NOTFOUND: vifs");
+		return 0;
+	}
+
+	offset = f->offset;
+	len = f->size;
+	if (f->flags & FIELD_IS_DYNAMIC) {
+		long long unsigned int val;
+
+		val = pevent_read_number(event->pevent, data + offset, len);
+		offset = val;
+		len = offset >> 16;
+		offset &= 0xffff;
+	}
+
+	if (len != sizeof(*vifs) * n_vifs) {
+		trace_seq_printf(s, "field-invalid: vifs");
+		return 0;
+	}
+
+	print_string(s, event, "wiphy_name", data);
+	pevent_print_num_field(s, " n_vifs:%d ", event, "n_vifs", record, 1);
+	print_enum(s, event, "mode", data,
+		   { 0, "REASSIGN_VIF" },
+		   { 1, "SWAP_CONTEXTS"} );
+
+	vifs = (void *) (char *) data + offset;
+
+	for (i = 0; i < n_vifs; i++) {
+		trace_seq_printf(s, "\n%*s\t", INDENT, "");
+		trace_seq_printf(s, "vif %d:\tname: %s type: %d p2p: %d",
+				 i, vifs[i].vif.vif_name, vifs[i].vif.vif_type,
+				 vifs[i].vif.p2p);
+		trace_seq_printf(s, "\n%*s\t\t", INDENT, "");
+		trace_seq_printf(s, "old_ctx: control_freq: %d chan_width: %d center_freq1: %d center_freq2: %d",
+				 vifs[i].old_chandef.control_freq,
+				 vifs[i].old_chandef.chan_width,
+				 vifs[i].old_chandef.center_freq1,
+				 vifs[i].old_chandef.center_freq2);
+		trace_seq_printf(s, "\n%*s\t\t", INDENT, "");
+		trace_seq_printf(s, "new_ctx: control_freq: %d chan_width: %d center_freq1: %d center_freq2: %d",
+				 vifs[i].new_chandef.control_freq,
+				 vifs[i].new_chandef.chan_width,
+				 vifs[i].new_chandef.center_freq1,
+				 vifs[i].new_chandef.center_freq2);
+	}
+
+	return 0;
+}
 int PEVENT_PLUGIN_LOADER(struct pevent *pevent)
 {
 	pevent_register_event_handler(pevent, -1, "mac80211", "drv_bss_info_changed",
 				      drv_bss_info_changed, NULL);
 	pevent_register_event_handler(pevent, -1, "mac80211", "drv_config",
 				      drv_config, NULL);
+	pevent_register_event_handler(pevent, -1, "mac80211", "drv_switch_vif_chanctx",
+				      drv_switch_vif_chanctx, NULL);
 
 	return 0;
 }
-- 
2.0.0.rc0