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/*
* Freescale GPMI NFC NAND Flash Driver
*
* Copyright (C) 2010 Freescale Semiconductor, Inc.
* Copyright (C) 2008 Embedded Alley Solutions, Inc.
*
* This program is free software; you can redistribute it and/or modify
* it under the terms of the GNU General Public License as published by
* the Free Software Foundation; either version 2 of the License, or
* (at your option) any later version.
*
* This program is distributed in the hope that it will be useful,
* but WITHOUT ANY WARRANTY; without even the implied warranty of
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
* GNU General Public License for more details.
*
* You should have received a copy of the GNU General Public License along
* with this program; if not, write to the Free Software Foundation, Inc.,
* 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA.
*/
#include "gpmi-nfc.h"
#if defined(EVENT_REPORTING)
/*
* This variable and module parameter controls whether the driver reports event
* information by printing to the console.
*/
static int report_events;
module_param(report_events, int, 0600);
/**
* struct event - A single record in the event trace.
*
* @time: The time at which the event occurred.
* @nesting: Indicates function call nesting.
* @description: A description of the event.
*/
struct event {
ktime_t time;
unsigned int nesting;
char *description;
};
/**
* The event trace.
*
* @overhead: The delay to take a time stamp and nothing else.
* @nesting: The current nesting level.
* @overflow: Indicates the trace overflowed.
* @next: Index of the next event to write.
* @events: The array of events.
*/
#define MAX_EVENT_COUNT (200)
static struct {
ktime_t overhead;
int nesting;
int overflow;
unsigned int next;
struct event events[MAX_EVENT_COUNT];
} event_trace;
/**
* gpmi_nfc_reset_event_trace() - Resets the event trace.
*/
void gpmi_nfc_reset_event_trace(void)
{
event_trace.nesting = 0;
event_trace.overflow = false;
event_trace.next = 0;
}
/**
* gpmi_nfc_add_event() - Adds an event to the event trace.
*
* @description: A description of the event.
* @delta: A delta to the nesting level for this event [-1, 0, 1].
*/
void gpmi_nfc_add_event(char *description, int delta)
{
struct event *event;
if (!report_events)
return;
if (event_trace.overflow)
return;
if (event_trace.next >= MAX_EVENT_COUNT) {
event_trace.overflow = true;
return;
}
event = event_trace.events + event_trace.next;
event->time = ktime_get();
event->description = description;
if (!delta)
event->nesting = event_trace.nesting;
else if (delta < 0) {
event->nesting = event_trace.nesting - 1;
event_trace.nesting -= 2;
} else {
event->nesting = event_trace.nesting + 1;
event_trace.nesting += 2;
}
if (event_trace.nesting < 0)
event_trace.nesting = 0;
event_trace.next++;
}
/**
* gpmi_nfc_start_event_trace() - Starts an event trace.
*
* @description: A description of the first event.
*/
void gpmi_nfc_start_event_trace(char *description)
{
ktime_t t0;
ktime_t t1;
if (!report_events)
return;
gpmi_nfc_reset_event_trace();
t0 = ktime_get();
t1 = ktime_get();
event_trace.overhead = ktime_sub(t1, t0);
gpmi_nfc_add_event(description, 1);
}
/**
* gpmi_nfc_dump_event_trace() - Dumps the event trace.
*/
void gpmi_nfc_dump_event_trace(void)
{
unsigned int i;
time_t seconds;
long nanoseconds;
char line[100];
int o;
struct event *first_event;
struct event *last_event;
struct event *matching_event;
struct event *event;
ktime_t delta;
/* Check if event reporting is turned off. */
if (!report_events)
return;
/* Print important facts about this event trace. */
pr_info("\n+----------------\n");
pr_info("| Overhead : [%d:%d]\n", event_trace.overhead.tv.sec,
event_trace.overhead.tv.nsec);
if (!event_trace.next) {
pr_info("| No Events\n");
return;
}
first_event = event_trace.events;
last_event = event_trace.events + (event_trace.next - 1);
delta = ktime_sub(last_event->time, first_event->time);
pr_info("| Elapsed Time: [%d:%d]\n", delta.tv.sec, delta.tv.nsec);
if (event_trace.overflow)
pr_info("| Overflow!\n");
/* Print the events in this history. */
for (i = 0, event = event_trace.events;
i < event_trace.next; i++, event++) {
/* Get the delta between this event and the previous event. */
if (!i) {
seconds = 0;
nanoseconds = 0;
} else {
delta = ktime_sub(event[0].time, event[-1].time);
seconds = delta.tv.sec;
nanoseconds = delta.tv.nsec;
}
/* Print the current event. */
o = 0;
o = snprintf(line, sizeof(line) - o, "| [%ld:% 10ld]%*s %s",
seconds, nanoseconds,
event->nesting, "",
event->description);
/* Check if this is the last event in a nested series. */
if (i && (event[0].nesting < event[-1].nesting)) {
for (matching_event = event - 1;; matching_event--) {
if (matching_event < event_trace.events) {
matching_event = 0;
break;
}
if (matching_event->nesting == event->nesting)
break;
}
if (matching_event) {
delta = ktime_sub(event->time,
matching_event->time);
o += snprintf(line + o, sizeof(line) - o,
" <%d:%d]", delta.tv.sec,
delta.tv.nsec);
}
}
/* Check if this is the first event in a nested series. */
if ((i < event_trace.next - 1) &&
(event[0].nesting < event[1].nesting)) {
for (matching_event = event + 1;; matching_event++) {
if (matching_event >=
(event_trace.events+event_trace.next)) {
matching_event = 0;
break;
}
if (matching_event->nesting == event->nesting)
break;
}
if (matching_event) {
delta = ktime_sub(matching_event->time,
event->time);
o += snprintf(line + o, sizeof(line) - o,
" [%d:%d>", delta.tv.sec,
delta.tv.nsec);
}
}
pr_info("%s\n", line);
}
pr_info("+----------------\n");
}
/**
* gpmi_nfc_stop_event_trace() - Stops an event trace.
*
* @description: A description of the last event.
*/
void gpmi_nfc_stop_event_trace(char *description)
{
struct event *event;
if (!report_events)
return;
/*
* We want the end of the trace, no matter what happens. If the trace
* has already overflowed, or is about to, just jam this event into the
* last spot. Otherwise, add this event like any other.
*/
if (event_trace.overflow || (event_trace.next >= MAX_EVENT_COUNT)) {
event = event_trace.events + (MAX_EVENT_COUNT - 1);
event->time = ktime_get();
event->description = description;
event->nesting = 0;
} else {
gpmi_nfc_add_event(description, -1);
}
gpmi_nfc_dump_event_trace();
gpmi_nfc_reset_event_trace();
}
#endif /* EVENT_REPORTING */
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