ocfs2: fix several issues of append dio

[linux/fpc-iii.git] / drivers / scsi / fnic / fnic_trace.c

/*
 * Copyright 2012 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/spinlock.h>
#include <linux/kallsyms.h>
#include <linux/time.h>
#include <linux/vmalloc.h>
#include "fnic_io.h"
#include "fnic.h"

unsigned int trace_max_pages;
static int fnic_max_trace_entries;

static unsigned long fnic_trace_buf_p;
static DEFINE_SPINLOCK(fnic_trace_lock);

static fnic_trace_dbg_t fnic_trace_entries;
int fnic_tracing_enabled = 1;

/* static char *fnic_fc_ctlr_trace_buf_p; */

static int fc_trace_max_entries;
static unsigned long fnic_fc_ctlr_trace_buf_p;
static fnic_trace_dbg_t fc_trace_entries;
int fnic_fc_tracing_enabled = 1;
int fnic_fc_trace_cleared = 1;
static DEFINE_SPINLOCK(fnic_fc_trace_lock);


/*
 * fnic_trace_get_buf - Give buffer pointer to user to fill up trace information
 *
 * Description:
 * This routine gets next available trace buffer entry location @wr_idx
 * from allocated trace buffer pages and give that memory location
 * to user to store the trace information.
 *
 * Return Value:
 * This routine returns pointer to next available trace entry
 * @fnic_buf_head for user to fill trace information.
 */
fnic_trace_data_t *fnic_trace_get_buf(void)
{
        unsigned long fnic_buf_head;
        unsigned long flags;

        spin_lock_irqsave(&fnic_trace_lock, flags);

        /*
         * Get next available memory location for writing trace information
         * at @wr_idx and increment @wr_idx
         */
        fnic_buf_head =
                fnic_trace_entries.page_offset[fnic_trace_entries.wr_idx];
        fnic_trace_entries.wr_idx++;

        /*
         * Verify if trace buffer is full then change wd_idx to
         * start from zero
         */
        if (fnic_trace_entries.wr_idx >= fnic_max_trace_entries)
                fnic_trace_entries.wr_idx = 0;

        /*
         * Verify if write index @wr_idx and read index @rd_idx are same then
         * increment @rd_idx to move to next entry in trace buffer
         */
        if (fnic_trace_entries.wr_idx == fnic_trace_entries.rd_idx) {
                fnic_trace_entries.rd_idx++;
                if (fnic_trace_entries.rd_idx >= fnic_max_trace_entries)
                        fnic_trace_entries.rd_idx = 0;
        }
        spin_unlock_irqrestore(&fnic_trace_lock, flags);
        return (fnic_trace_data_t *)fnic_buf_head;
}

/*
 * fnic_get_trace_data - Copy trace buffer to a memory file
 * @fnic_dbgfs_t: pointer to debugfs trace buffer
 *
 * Description:
 * This routine gathers the fnic trace debugfs data from the fnic_trace_data_t
 * buffer and dumps it to fnic_dbgfs_t. It will start at the rd_idx entry in
 * the log and process the log until the end of the buffer. Then it will gather
 * from the beginning of the log and process until the current entry @wr_idx.
 *
 * Return Value:
 * This routine returns the amount of bytes that were dumped into fnic_dbgfs_t
 */
int fnic_get_trace_data(fnic_dbgfs_t *fnic_dbgfs_prt)
{
        int rd_idx;
        int wr_idx;
        int len = 0;
        unsigned long flags;
        char str[KSYM_SYMBOL_LEN];
        struct timespec val;
        fnic_trace_data_t *tbp;

        spin_lock_irqsave(&fnic_trace_lock, flags);
        rd_idx = fnic_trace_entries.rd_idx;
        wr_idx = fnic_trace_entries.wr_idx;
        if (wr_idx < rd_idx) {
                while (1) {
                        /* Start from read index @rd_idx */
                        tbp = (fnic_trace_data_t *)
                                  fnic_trace_entries.page_offset[rd_idx];
                        if (!tbp) {
                                spin_unlock_irqrestore(&fnic_trace_lock, flags);
                                return 0;
                        }
                        /* Convert function pointer to function name */
                        if (sizeof(unsigned long) < 8) {
                                sprint_symbol(str, tbp->fnaddr.low);
                                jiffies_to_timespec(tbp->timestamp.low, &val);
                        } else {
                                sprint_symbol(str, tbp->fnaddr.val);
                                jiffies_to_timespec(tbp->timestamp.val, &val);
                        }
                        /*
                         * Dump trace buffer entry to memory file
                         * and increment read index @rd_idx
                         */
                        len += snprintf(fnic_dbgfs_prt->buffer + len,
                                  (trace_max_pages * PAGE_SIZE * 3) - len,
                                  "%16lu.%16lu %-50s %8x %8x %16llx %16llx "
                                  "%16llx %16llx %16llx\n", val.tv_sec,
                                  val.tv_nsec, str, tbp->host_no, tbp->tag,
                                  tbp->data[0], tbp->data[1], tbp->data[2],
                                  tbp->data[3], tbp->data[4]);
                        rd_idx++;
                        /*
                         * If rd_idx is reached to maximum trace entries
                         * then move rd_idx to zero
                         */
                        if (rd_idx > (fnic_max_trace_entries-1))
                                rd_idx = 0;
                        /*
                         * Continure dumpping trace buffer entries into
                         * memory file till rd_idx reaches write index
                         */
                        if (rd_idx == wr_idx)
                                break;
                }
        } else if (wr_idx > rd_idx) {
                while (1) {
                        /* Start from read index @rd_idx */
                        tbp = (fnic_trace_data_t *)
                                  fnic_trace_entries.page_offset[rd_idx];
                        if (!tbp) {
                                spin_unlock_irqrestore(&fnic_trace_lock, flags);
                                return 0;
                        }
                        /* Convert function pointer to function name */
                        if (sizeof(unsigned long) < 8) {
                                sprint_symbol(str, tbp->fnaddr.low);
                                jiffies_to_timespec(tbp->timestamp.low, &val);
                        } else {
                                sprint_symbol(str, tbp->fnaddr.val);
                                jiffies_to_timespec(tbp->timestamp.val, &val);
                        }
                        /*
                         * Dump trace buffer entry to memory file
                         * and increment read index @rd_idx
                         */
                        len += snprintf(fnic_dbgfs_prt->buffer + len,
                                  (trace_max_pages * PAGE_SIZE * 3) - len,
                                  "%16lu.%16lu %-50s %8x %8x %16llx %16llx "
                                  "%16llx %16llx %16llx\n", val.tv_sec,
                                  val.tv_nsec, str, tbp->host_no, tbp->tag,
                                  tbp->data[0], tbp->data[1], tbp->data[2],
                                  tbp->data[3], tbp->data[4]);
                        rd_idx++;
                        /*
                         * Continue dumpping trace buffer entries into
                         * memory file till rd_idx reaches write index
                         */
                        if (rd_idx == wr_idx)
                                break;
                }
        }
        spin_unlock_irqrestore(&fnic_trace_lock, flags);
        return len;
}

/*
 * fnic_get_stats_data - Copy fnic stats buffer to a memory file
 * @fnic_dbgfs_t: pointer to debugfs fnic stats buffer
 *
 * Description:
 * This routine gathers the fnic stats debugfs data from the fnic_stats struct
 * and dumps it to stats_debug_info.
 *
 * Return Value:
 * This routine returns the amount of bytes that were dumped into
 * stats_debug_info
 */
int fnic_get_stats_data(struct stats_debug_info *debug,
                        struct fnic_stats *stats)
{
        int len = 0;
        int buf_size = debug->buf_size;
        struct timespec val1, val2;

        len = snprintf(debug->debug_buffer + len, buf_size - len,
                  "------------------------------------------\n"
                  "\t\tIO Statistics\n"
                  "------------------------------------------\n");
        len += snprintf(debug->debug_buffer + len, buf_size - len,
                  "Number of Active IOs: %lld\nMaximum Active IOs: %lld\n"
                  "Number of IOs: %lld\nNumber of IO Completions: %lld\n"
                  "Number of IO Failures: %lld\nNumber of IO NOT Found: %lld\n"
                  "Number of Memory alloc Failures: %lld\n"
                  "Number of IOREQ Null: %lld\n"
                  "Number of SCSI cmd pointer Null: %lld\n",
                  (u64)atomic64_read(&stats->io_stats.active_ios),
                  (u64)atomic64_read(&stats->io_stats.max_active_ios),
                  (u64)atomic64_read(&stats->io_stats.num_ios),
                  (u64)atomic64_read(&stats->io_stats.io_completions),
                  (u64)atomic64_read(&stats->io_stats.io_failures),
                  (u64)atomic64_read(&stats->io_stats.io_not_found),
                  (u64)atomic64_read(&stats->io_stats.alloc_failures),
                  (u64)atomic64_read(&stats->io_stats.ioreq_null),
                  (u64)atomic64_read(&stats->io_stats.sc_null));

        len += snprintf(debug->debug_buffer + len, buf_size - len,
                  "\n------------------------------------------\n"
                  "\t\tAbort Statistics\n"
                  "------------------------------------------\n");
        len += snprintf(debug->debug_buffer + len, buf_size - len,
                  "Number of Aborts: %lld\n"
                  "Number of Abort Failures: %lld\n"
                  "Number of Abort Driver Timeouts: %lld\n"
                  "Number of Abort FW Timeouts: %lld\n"
                  "Number of Abort IO NOT Found: %lld\n",
                  (u64)atomic64_read(&stats->abts_stats.aborts),
                  (u64)atomic64_read(&stats->abts_stats.abort_failures),
                  (u64)atomic64_read(&stats->abts_stats.abort_drv_timeouts),
                  (u64)atomic64_read(&stats->abts_stats.abort_fw_timeouts),
                  (u64)atomic64_read(&stats->abts_stats.abort_io_not_found));

        len += snprintf(debug->debug_buffer + len, buf_size - len,
                  "\n------------------------------------------\n"
                  "\t\tTerminate Statistics\n"
                  "------------------------------------------\n");
        len += snprintf(debug->debug_buffer + len, buf_size - len,
                  "Number of Terminates: %lld\n"
                  "Maximum Terminates: %lld\n"
                  "Number of Terminate Driver Timeouts: %lld\n"
                  "Number of Terminate FW Timeouts: %lld\n"
                  "Number of Terminate IO NOT Found: %lld\n"
                  "Number of Terminate Failures: %lld\n",
                  (u64)atomic64_read(&stats->term_stats.terminates),
                  (u64)atomic64_read(&stats->term_stats.max_terminates),
                  (u64)atomic64_read(&stats->term_stats.terminate_drv_timeouts),
                  (u64)atomic64_read(&stats->term_stats.terminate_fw_timeouts),
                  (u64)atomic64_read(&stats->term_stats.terminate_io_not_found),
                  (u64)atomic64_read(&stats->term_stats.terminate_failures));

        len += snprintf(debug->debug_buffer + len, buf_size - len,
                  "\n------------------------------------------\n"
                  "\t\tReset Statistics\n"
                  "------------------------------------------\n");

        len += snprintf(debug->debug_buffer + len, buf_size - len,
                  "Number of Device Resets: %lld\n"
                  "Number of Device Reset Failures: %lld\n"
                  "Number of Device Reset Aborts: %lld\n"
                  "Number of Device Reset Timeouts: %lld\n"
                  "Number of Device Reset Terminates: %lld\n"
                  "Number of FW Resets: %lld\n"
                  "Number of FW Reset Completions: %lld\n"
                  "Number of FW Reset Failures: %lld\n"
                  "Number of Fnic Reset: %lld\n"
                  "Number of Fnic Reset Completions: %lld\n"
                  "Number of Fnic Reset Failures: %lld\n",
                  (u64)atomic64_read(&stats->reset_stats.device_resets),
                  (u64)atomic64_read(&stats->reset_stats.device_reset_failures),
                  (u64)atomic64_read(&stats->reset_stats.device_reset_aborts),
                  (u64)atomic64_read(&stats->reset_stats.device_reset_timeouts),
                  (u64)atomic64_read(
                          &stats->reset_stats.device_reset_terminates),
                  (u64)atomic64_read(&stats->reset_stats.fw_resets),
                  (u64)atomic64_read(&stats->reset_stats.fw_reset_completions),
                  (u64)atomic64_read(&stats->reset_stats.fw_reset_failures),
                  (u64)atomic64_read(&stats->reset_stats.fnic_resets),
                  (u64)atomic64_read(
                          &stats->reset_stats.fnic_reset_completions),
                  (u64)atomic64_read(&stats->reset_stats.fnic_reset_failures));

        len += snprintf(debug->debug_buffer + len, buf_size - len,
                  "\n------------------------------------------\n"
                  "\t\tFirmware Statistics\n"
                  "------------------------------------------\n");

        len += snprintf(debug->debug_buffer + len, buf_size - len,
                  "Number of Active FW Requests %lld\n"
                  "Maximum FW Requests: %lld\n"
                  "Number of FW out of resources: %lld\n"
                  "Number of FW IO errors: %lld\n",
                  (u64)atomic64_read(&stats->fw_stats.active_fw_reqs),
                  (u64)atomic64_read(&stats->fw_stats.max_fw_reqs),
                  (u64)atomic64_read(&stats->fw_stats.fw_out_of_resources),
                  (u64)atomic64_read(&stats->fw_stats.io_fw_errs));

        len += snprintf(debug->debug_buffer + len, buf_size - len,
                  "\n------------------------------------------\n"
                  "\t\tVlan Discovery Statistics\n"
                  "------------------------------------------\n");

        len += snprintf(debug->debug_buffer + len, buf_size - len,
                  "Number of Vlan Discovery Requests Sent %lld\n"
                  "Vlan Response Received with no FCF VLAN ID: %lld\n"
                  "No solicitations recvd after vlan set, expiry count: %lld\n"
                  "Flogi rejects count: %lld\n",
                  (u64)atomic64_read(&stats->vlan_stats.vlan_disc_reqs),
                  (u64)atomic64_read(&stats->vlan_stats.resp_withno_vlanID),
                  (u64)atomic64_read(&stats->vlan_stats.sol_expiry_count),
                  (u64)atomic64_read(&stats->vlan_stats.flogi_rejects));

        len += snprintf(debug->debug_buffer + len, buf_size - len,
                  "\n------------------------------------------\n"
                  "\t\tOther Important Statistics\n"
                  "------------------------------------------\n");

        jiffies_to_timespec(stats->misc_stats.last_isr_time, &val1);
        jiffies_to_timespec(stats->misc_stats.last_ack_time, &val2);

        len += snprintf(debug->debug_buffer + len, buf_size - len,
                  "Last ISR time: %llu (%8lu.%8lu)\n"
                  "Last ACK time: %llu (%8lu.%8lu)\n"
                  "Number of ISRs: %lld\n"
                  "Maximum CQ Entries: %lld\n"
                  "Number of ACK index out of range: %lld\n"
                  "Number of data count mismatch: %lld\n"
                  "Number of FCPIO Timeouts: %lld\n"
                  "Number of FCPIO Aborted: %lld\n"
                  "Number of SGL Invalid: %lld\n"
                  "Number of Copy WQ Alloc Failures for ABTs: %lld\n"
                  "Number of Copy WQ Alloc Failures for Device Reset: %lld\n"
                  "Number of Copy WQ Alloc Failures for IOs: %lld\n"
                  "Number of no icmnd itmf Completions: %lld\n"
                  "Number of QUEUE Fulls: %lld\n"
                  "Number of rport not ready: %lld\n"
                  "Number of receive frame errors: %lld\n",
                  (u64)stats->misc_stats.last_isr_time,
                  val1.tv_sec, val1.tv_nsec,
                  (u64)stats->misc_stats.last_ack_time,
                  val2.tv_sec, val2.tv_nsec,
                  (u64)atomic64_read(&stats->misc_stats.isr_count),
                  (u64)atomic64_read(&stats->misc_stats.max_cq_entries),
                  (u64)atomic64_read(&stats->misc_stats.ack_index_out_of_range),
                  (u64)atomic64_read(&stats->misc_stats.data_count_mismatch),
                  (u64)atomic64_read(&stats->misc_stats.fcpio_timeout),
                  (u64)atomic64_read(&stats->misc_stats.fcpio_aborted),
                  (u64)atomic64_read(&stats->misc_stats.sgl_invalid),
                  (u64)atomic64_read(
                          &stats->misc_stats.abts_cpwq_alloc_failures),
                  (u64)atomic64_read(
                          &stats->misc_stats.devrst_cpwq_alloc_failures),
                  (u64)atomic64_read(&stats->misc_stats.io_cpwq_alloc_failures),
                  (u64)atomic64_read(&stats->misc_stats.no_icmnd_itmf_cmpls),
                  (u64)atomic64_read(&stats->misc_stats.queue_fulls),
                  (u64)atomic64_read(&stats->misc_stats.rport_not_ready),
                  (u64)atomic64_read(&stats->misc_stats.frame_errors));

        return len;

}

/*
 * fnic_trace_buf_init - Initialize fnic trace buffer logging facility
 *
 * Description:
 * Initialize trace buffer data structure by allocating required memory and
 * setting page_offset information for every trace entry by adding trace entry
 * length to previous page_offset value.
 */
int fnic_trace_buf_init(void)
{
        unsigned long fnic_buf_head;
        int i;
        int err = 0;

        trace_max_pages = fnic_trace_max_pages;
        fnic_max_trace_entries = (trace_max_pages * PAGE_SIZE)/
                                          FNIC_ENTRY_SIZE_BYTES;

        fnic_trace_buf_p = (unsigned long)vmalloc((trace_max_pages * PAGE_SIZE));
        if (!fnic_trace_buf_p) {
                printk(KERN_ERR PFX "Failed to allocate memory "
                                  "for fnic_trace_buf_p\n");
                err = -ENOMEM;
                goto err_fnic_trace_buf_init;
        }
        memset((void *)fnic_trace_buf_p, 0, (trace_max_pages * PAGE_SIZE));

        fnic_trace_entries.page_offset = vmalloc(fnic_max_trace_entries *
                                                  sizeof(unsigned long));
        if (!fnic_trace_entries.page_offset) {
                printk(KERN_ERR PFX "Failed to allocate memory for"
                                  " page_offset\n");
                if (fnic_trace_buf_p) {
                        vfree((void *)fnic_trace_buf_p);
                        fnic_trace_buf_p = 0;
                }
                err = -ENOMEM;
                goto err_fnic_trace_buf_init;
        }
        memset((void *)fnic_trace_entries.page_offset, 0,
                  (fnic_max_trace_entries * sizeof(unsigned long)));
        fnic_trace_entries.wr_idx = fnic_trace_entries.rd_idx = 0;
        fnic_buf_head = fnic_trace_buf_p;

        /*
         * Set page_offset field of fnic_trace_entries struct by
         * calculating memory location for every trace entry using
         * length of each trace entry
         */
        for (i = 0; i < fnic_max_trace_entries; i++) {
                fnic_trace_entries.page_offset[i] = fnic_buf_head;
                fnic_buf_head += FNIC_ENTRY_SIZE_BYTES;
        }
        err = fnic_trace_debugfs_init();
        if (err < 0) {
                pr_err("fnic: Failed to initialize debugfs for tracing\n");
                goto err_fnic_trace_debugfs_init;
        }
        pr_info("fnic: Successfully Initialized Trace Buffer\n");
        return err;
err_fnic_trace_debugfs_init:
        fnic_trace_free();
err_fnic_trace_buf_init:
        return err;
}

/*
 * fnic_trace_free - Free memory of fnic trace data structures.
 */
void fnic_trace_free(void)
{
        fnic_tracing_enabled = 0;
        fnic_trace_debugfs_terminate();
        if (fnic_trace_entries.page_offset) {
                vfree((void *)fnic_trace_entries.page_offset);
                fnic_trace_entries.page_offset = NULL;
        }
        if (fnic_trace_buf_p) {
                vfree((void *)fnic_trace_buf_p);
                fnic_trace_buf_p = 0;
        }
        printk(KERN_INFO PFX "Successfully Freed Trace Buffer\n");
}

/*
 * fnic_fc_ctlr_trace_buf_init -
 * Initialize trace buffer to log fnic control frames
 * Description:
 * Initialize trace buffer data structure by allocating
 * required memory for trace data as well as for Indexes.
 * Frame size is 256 bytes and
 * memory is allocated for 1024 entries of 256 bytes.
 * Page_offset(Index) is set to the address of trace entry
 * and page_offset is initialized by adding frame size
 * to the previous page_offset entry.
 */

int fnic_fc_trace_init(void)
{
        unsigned long fc_trace_buf_head;
        int err = 0;
        int i;

        fc_trace_max_entries = (fnic_fc_trace_max_pages * PAGE_SIZE)/
                                FC_TRC_SIZE_BYTES;
        fnic_fc_ctlr_trace_buf_p = (unsigned long)vmalloc(
                                        fnic_fc_trace_max_pages * PAGE_SIZE);
        if (!fnic_fc_ctlr_trace_buf_p) {
                pr_err("fnic: Failed to allocate memory for "
                       "FC Control Trace Buf\n");
                err = -ENOMEM;
                goto err_fnic_fc_ctlr_trace_buf_init;
        }

        memset((void *)fnic_fc_ctlr_trace_buf_p, 0,
                        fnic_fc_trace_max_pages * PAGE_SIZE);

        /* Allocate memory for page offset */
        fc_trace_entries.page_offset = vmalloc(fc_trace_max_entries *
                                                sizeof(unsigned long));
        if (!fc_trace_entries.page_offset) {
                pr_err("fnic:Failed to allocate memory for page_offset\n");
                if (fnic_fc_ctlr_trace_buf_p) {
                        pr_err("fnic: Freeing FC Control Trace Buf\n");
                        vfree((void *)fnic_fc_ctlr_trace_buf_p);
                        fnic_fc_ctlr_trace_buf_p = 0;
                }
                err = -ENOMEM;
                goto err_fnic_fc_ctlr_trace_buf_init;
        }
        memset((void *)fc_trace_entries.page_offset, 0,
               (fc_trace_max_entries * sizeof(unsigned long)));

        fc_trace_entries.rd_idx = fc_trace_entries.wr_idx = 0;
        fc_trace_buf_head = fnic_fc_ctlr_trace_buf_p;

        /*
        * Set up fc_trace_entries.page_offset field with memory location
        * for every trace entry
        */
        for (i = 0; i < fc_trace_max_entries; i++) {
                fc_trace_entries.page_offset[i] = fc_trace_buf_head;
                fc_trace_buf_head += FC_TRC_SIZE_BYTES;
        }
        err = fnic_fc_trace_debugfs_init();
        if (err < 0) {
                pr_err("fnic: Failed to initialize FC_CTLR tracing.\n");
                goto err_fnic_fc_ctlr_trace_debugfs_init;
        }
        pr_info("fnic: Successfully Initialized FC_CTLR Trace Buffer\n");
        return err;

err_fnic_fc_ctlr_trace_debugfs_init:
        fnic_fc_trace_free();
err_fnic_fc_ctlr_trace_buf_init:
        return err;
}

/*
 * Fnic_fc_ctlr_trace_free - Free memory of fnic_fc_ctlr trace data structures.
 */
void fnic_fc_trace_free(void)
{
        fnic_fc_tracing_enabled = 0;
        fnic_fc_trace_debugfs_terminate();
        if (fc_trace_entries.page_offset) {
                vfree((void *)fc_trace_entries.page_offset);
                fc_trace_entries.page_offset = NULL;
        }
        if (fnic_fc_ctlr_trace_buf_p) {
                vfree((void *)fnic_fc_ctlr_trace_buf_p);
                fnic_fc_ctlr_trace_buf_p = 0;
        }
        pr_info("fnic:Successfully FC_CTLR Freed Trace Buffer\n");
}

/*
 * fnic_fc_ctlr_set_trace_data:
 *       Maintain rd & wr idx accordingly and set data
 * Passed parameters:
 *       host_no: host number accociated with fnic
 *       frame_type: send_frame, rece_frame or link event
 *       fc_frame: pointer to fc_frame
 *       frame_len: Length of the fc_frame
 * Description:
 *   This routine will get next available wr_idx and
 *   copy all passed trace data to the buffer pointed by wr_idx
 *   and increment wr_idx. It will also make sure that we dont
 *   overwrite the entry which we are reading and also
 *   wrap around if we reach the maximum entries.
 * Returned Value:
 *   It will return 0 for success or -1 for failure
 */
int fnic_fc_trace_set_data(u32 host_no, u8 frame_type,
                                char *frame, u32 fc_trc_frame_len)
{
        unsigned long flags;
        struct fc_trace_hdr *fc_buf;
        unsigned long eth_fcoe_hdr_len;
        char *fc_trace;

        if (fnic_fc_tracing_enabled == 0)
                return 0;

        spin_lock_irqsave(&fnic_fc_trace_lock, flags);

        if (fnic_fc_trace_cleared == 1) {
                fc_trace_entries.rd_idx = fc_trace_entries.wr_idx = 0;
                pr_info("fnic: Resetting the read idx\n");
                memset((void *)fnic_fc_ctlr_trace_buf_p, 0,
                                fnic_fc_trace_max_pages * PAGE_SIZE);
                fnic_fc_trace_cleared = 0;
        }

        fc_buf = (struct fc_trace_hdr *)
                fc_trace_entries.page_offset[fc_trace_entries.wr_idx];

        fc_trace_entries.wr_idx++;

        if (fc_trace_entries.wr_idx >= fc_trace_max_entries)
                fc_trace_entries.wr_idx = 0;

        if (fc_trace_entries.wr_idx == fc_trace_entries.rd_idx) {
                fc_trace_entries.rd_idx++;
                if (fc_trace_entries.rd_idx >= fc_trace_max_entries)
                        fc_trace_entries.rd_idx = 0;
        }

        fc_buf->time_stamp = CURRENT_TIME;
        fc_buf->host_no = host_no;
        fc_buf->frame_type = frame_type;

        fc_trace = (char *)FC_TRACE_ADDRESS(fc_buf);

        /* During the receive path, we do not have eth hdr as well as fcoe hdr
         * at trace entry point so we will stuff 0xff just to make it generic.
         */
        if (frame_type == FNIC_FC_RECV) {
                eth_fcoe_hdr_len = sizeof(struct ethhdr) +
                                        sizeof(struct fcoe_hdr);
                memset((char *)fc_trace, 0xff, eth_fcoe_hdr_len);
                /* Copy the rest of data frame */
                memcpy((char *)(fc_trace + eth_fcoe_hdr_len), (void *)frame,
                min_t(u8, fc_trc_frame_len,
                        (u8)(FC_TRC_SIZE_BYTES - FC_TRC_HEADER_SIZE
                                                - eth_fcoe_hdr_len)));
        } else {
                memcpy((char *)fc_trace, (void *)frame,
                min_t(u8, fc_trc_frame_len,
                        (u8)(FC_TRC_SIZE_BYTES - FC_TRC_HEADER_SIZE)));
        }

        /* Store the actual received length */
        fc_buf->frame_len = fc_trc_frame_len;

        spin_unlock_irqrestore(&fnic_fc_trace_lock, flags);
        return 0;
}

/*
 * fnic_fc_ctlr_get_trace_data: Copy trace buffer to a memory file
 * Passed parameter:
 *       @fnic_dbgfs_t: pointer to debugfs trace buffer
 *       rdata_flag: 1 => Unformated file
 *                   0 => formated file
 * Description:
 *       This routine will copy the trace data to memory file with
 *       proper formatting and also copy to another memory
 *       file without formatting for further procesing.
 * Retrun Value:
 *       Number of bytes that were dumped into fnic_dbgfs_t
 */

int fnic_fc_trace_get_data(fnic_dbgfs_t *fnic_dbgfs_prt, u8 rdata_flag)
{
        int rd_idx, wr_idx;
        unsigned long flags;
        int len = 0, j;
        struct fc_trace_hdr *tdata;
        char *fc_trace;

        spin_lock_irqsave(&fnic_fc_trace_lock, flags);
        if (fc_trace_entries.wr_idx == fc_trace_entries.rd_idx) {
                spin_unlock_irqrestore(&fnic_fc_trace_lock, flags);
                pr_info("fnic: Buffer is empty\n");
                return 0;
        }
        rd_idx = fc_trace_entries.rd_idx;
        wr_idx = fc_trace_entries.wr_idx;
        if (rdata_flag == 0) {
                len += snprintf(fnic_dbgfs_prt->buffer + len,
                        (fnic_fc_trace_max_pages * PAGE_SIZE * 3) - len,
                        "Time Stamp (UTC)\t\t"
                        "Host No:   F Type:  len:     FCoE_FRAME:\n");
        }

        while (rd_idx != wr_idx) {
                tdata = (struct fc_trace_hdr *)
                        fc_trace_entries.page_offset[rd_idx];
                if (!tdata) {
                        pr_info("fnic: Rd data is NULL\n");
                        spin_unlock_irqrestore(&fnic_fc_trace_lock, flags);
                        return 0;
                }
                if (rdata_flag == 0) {
                        copy_and_format_trace_data(tdata,
                                fnic_dbgfs_prt, &len, rdata_flag);
                } else {
                        fc_trace = (char *)tdata;
                        for (j = 0; j < FC_TRC_SIZE_BYTES; j++) {
                                len += snprintf(fnic_dbgfs_prt->buffer + len,
                                (fnic_fc_trace_max_pages * PAGE_SIZE * 3)
                                - len, "%02x", fc_trace[j] & 0xff);
                        } /* for loop */
                        len += snprintf(fnic_dbgfs_prt->buffer + len,
                                (fnic_fc_trace_max_pages * PAGE_SIZE * 3) - len,
                                "\n");
                }
                rd_idx++;
                if (rd_idx > (fc_trace_max_entries - 1))
                        rd_idx = 0;
        }

        spin_unlock_irqrestore(&fnic_fc_trace_lock, flags);
        return len;
}

/*
 * copy_and_format_trace_data: Copy formatted data to char * buffer
 * Passed Parameter:
 *      @fc_trace_hdr_t: pointer to trace data
 *      @fnic_dbgfs_t: pointer to debugfs trace buffer
 *      @orig_len: pointer to len
 *      rdata_flag: 0 => Formated file, 1 => Unformated file
 * Description:
 *      This routine will format and copy the passed trace data
 *      for formated file or unformated file accordingly.
 */

void copy_and_format_trace_data(struct fc_trace_hdr *tdata,
                                fnic_dbgfs_t *fnic_dbgfs_prt, int *orig_len,
                                u8 rdata_flag)
{
        struct tm tm;
        int j, i = 1, len;
        char *fc_trace, *fmt;
        int ethhdr_len = sizeof(struct ethhdr) - 1;
        int fcoehdr_len = sizeof(struct fcoe_hdr);
        int fchdr_len = sizeof(struct fc_frame_header);
        int max_size = fnic_fc_trace_max_pages * PAGE_SIZE * 3;

        tdata->frame_type = tdata->frame_type & 0x7F;

        len = *orig_len;

        time_to_tm(tdata->time_stamp.tv_sec, 0, &tm);

        fmt = "%02d:%02d:%04ld %02d:%02d:%02d.%09lu ns%8x       %c%8x\t";
        len += snprintf(fnic_dbgfs_prt->buffer + len,
                max_size - len,
                fmt,
                tm.tm_mon + 1, tm.tm_mday, tm.tm_year + 1900,
                tm.tm_hour, tm.tm_min, tm.tm_sec,
                tdata->time_stamp.tv_nsec, tdata->host_no,
                tdata->frame_type, tdata->frame_len);

        fc_trace = (char *)FC_TRACE_ADDRESS(tdata);

        for (j = 0; j < min_t(u8, tdata->frame_len,
                (u8)(FC_TRC_SIZE_BYTES - FC_TRC_HEADER_SIZE)); j++) {
                if (tdata->frame_type == FNIC_FC_LE) {
                        len += snprintf(fnic_dbgfs_prt->buffer + len,
                                max_size - len, "%c", fc_trace[j]);
                } else {
                        len += snprintf(fnic_dbgfs_prt->buffer + len,
                                max_size - len, "%02x", fc_trace[j] & 0xff);
                        len += snprintf(fnic_dbgfs_prt->buffer + len,
                                max_size - len, " ");
                        if (j == ethhdr_len ||
                                j == ethhdr_len + fcoehdr_len ||
                                j == ethhdr_len + fcoehdr_len + fchdr_len ||
                                (i > 3 && j%fchdr_len == 0)) {
                                len += snprintf(fnic_dbgfs_prt->buffer
                                        + len, max_size - len,
                                        "\n\t\t\t\t\t\t\t\t");
                                i++;
                        }
                } /* end of else*/
        } /* End of for loop*/
        len += snprintf(fnic_dbgfs_prt->buffer + len,
                max_size - len, "\n");
        *orig_len = len;
}