linux-stable/drivers/scsi/snic/snic_trc.c
Greg Kroah-Hartman fd84ec206d scsi: snic: no need to check return value of debugfs_create functions
When calling debugfs functions, there is no need to ever check the return
value.  The function can work or not, but the code logic should never do
something different based on this.

Cc: Karan Tilak Kumar <kartilak@cisco.com>
Cc: Sesidhar Baddela <sebaddel@cisco.com>
Cc: "James E.J. Bottomley" <jejb@linux.ibm.com>
Cc: "Martin K. Petersen" <martin.petersen@oracle.com>
Cc: linux-scsi@vger.kernel.org
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com>
2019-01-29 00:40:54 -05:00

170 lines
3.8 KiB
C

/*
* Copyright 2014 Cisco Systems, Inc. All rights reserved.
*
* This program is free software; you may redistribute it and/or modify
* it under the terms of the GNU General Public License as published by
* the Free Software Foundation; version 2 of the License.
*
* THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND,
* EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF
* MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND
* NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS
* BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN
* ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN
* CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
* SOFTWARE.
*/
#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 */