1 files changed, 273 insertions, 0 deletions
diff --git a/drivers/scsi/fnic/fnic_trace.c b/drivers/scsi/fnic/fnic_trace.c
new file mode 100644
index 00000000000..23a60e3d852
--- /dev/null
+++ b/drivers/scsi/fnic/fnic_trace.c
@@ -0,0 +1,273 @@
+/*
+ * 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 "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;
+
+/*
+ * 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_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) {
+		printk(KERN_ERR PFX "Failed to initialize debugfs for tracing\n");
+		goto err_fnic_trace_debugfs_init;
+	}
+	printk(KERN_INFO PFX "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");
+}