https://github.com/torvalds/linux
Tip revision: 6465e260f48790807eef06b583b38ca9789b6072 authored by Linus Torvalds on 24 September 2023, 21:31:13 UTC
Linux 6.6-rc3
Linux 6.6-rc3
Tip revision: 6465e26
snic_trc.c
// SPDX-License-Identifier: GPL-2.0-only
// Copyright 2014 Cisco Systems, Inc. All rights reserved.
#include <linux/module.h>
#include <linux/mempool.h>
#include <linux/errno.h>
#include <linux/vmalloc.h>
#include "snic_io.h"
#include "snic.h"
/*
* snic_get_trc_buf : Allocates a trace record and returns.
*/
struct snic_trc_data *
snic_get_trc_buf(void)
{
struct snic_trc *trc = &snic_glob->trc;
struct snic_trc_data *td = NULL;
unsigned long flags;
spin_lock_irqsave(&trc->lock, flags);
td = &trc->buf[trc->wr_idx];
trc->wr_idx++;
if (trc->wr_idx == trc->max_idx)
trc->wr_idx = 0;
if (trc->wr_idx != trc->rd_idx) {
spin_unlock_irqrestore(&trc->lock, flags);
goto end;
}
trc->rd_idx++;
if (trc->rd_idx == trc->max_idx)
trc->rd_idx = 0;
td->ts = 0; /* Marker for checking the record, for complete data*/
spin_unlock_irqrestore(&trc->lock, flags);
end:
return td;
} /* end of snic_get_trc_buf */
/*
* snic_fmt_trc_data : Formats trace data for printing.
*/
static int
snic_fmt_trc_data(struct snic_trc_data *td, char *buf, int buf_sz)
{
int len = 0;
struct timespec64 tmspec;
jiffies_to_timespec64(td->ts, &tmspec);
len += snprintf(buf, buf_sz,
"%llu.%09lu %-25s %3d %4x %16llx %16llx %16llx %16llx %16llx\n",
tmspec.tv_sec,
tmspec.tv_nsec,
td->fn,
td->hno,
td->tag,
td->data[0], td->data[1], td->data[2], td->data[3],
td->data[4]);
return len;
} /* end of snic_fmt_trc_data */
/*
* snic_get_trc_data : Returns a formatted trace buffer.
*/
int
snic_get_trc_data(char *buf, int buf_sz)
{
struct snic_trc_data *td = NULL;
struct snic_trc *trc = &snic_glob->trc;
unsigned long flags;
spin_lock_irqsave(&trc->lock, flags);
if (trc->rd_idx == trc->wr_idx) {
spin_unlock_irqrestore(&trc->lock, flags);
return -1;
}
td = &trc->buf[trc->rd_idx];
if (td->ts == 0) {
/* write in progress. */
spin_unlock_irqrestore(&trc->lock, flags);
return -1;
}
trc->rd_idx++;
if (trc->rd_idx == trc->max_idx)
trc->rd_idx = 0;
spin_unlock_irqrestore(&trc->lock, flags);
return snic_fmt_trc_data(td, buf, buf_sz);
} /* end of snic_get_trc_data */
/*
* snic_trc_init() : Configures Trace Functionality for snic.
*/
int
snic_trc_init(void)
{
struct snic_trc *trc = &snic_glob->trc;
void *tbuf = NULL;
int tbuf_sz = 0, ret;
tbuf_sz = (snic_trace_max_pages * PAGE_SIZE);
tbuf = vzalloc(tbuf_sz);
if (!tbuf) {
SNIC_ERR("Failed to Allocate Trace Buffer Size. %d\n", tbuf_sz);
SNIC_ERR("Trace Facility not enabled.\n");
ret = -ENOMEM;
return ret;
}
trc->buf = (struct snic_trc_data *) tbuf;
spin_lock_init(&trc->lock);
snic_trc_debugfs_init();
trc->max_idx = (tbuf_sz / SNIC_TRC_ENTRY_SZ);
trc->rd_idx = trc->wr_idx = 0;
trc->enable = true;
SNIC_INFO("Trace Facility Enabled.\n Trace Buffer SZ %lu Pages.\n",
tbuf_sz / PAGE_SIZE);
ret = 0;
return ret;
} /* end of snic_trc_init */
/*
* snic_trc_free : Releases the trace buffer and disables the tracing.
*/
void
snic_trc_free(void)
{
struct snic_trc *trc = &snic_glob->trc;
trc->enable = false;
snic_trc_debugfs_term();
if (trc->buf) {
vfree(trc->buf);
trc->buf = NULL;
}
SNIC_INFO("Trace Facility Disabled.\n");
} /* end of snic_trc_free */