fnic: fnic Control Path Trace Utility

Fnic Ctlr Path Trace utility is a tracing functionality built directly into fnic
driver to trace the control path frames like discovery, FLOGI request/reply,
PLOGI request/reply, link event etc.  It will be one trace file for all fnics.
It will help us to debug and resolve the discovery and initialization related
issues in more convenient way. This trace information includes time stamp,
Host Number, Frame type, Frame Length and Frame. By default,64 pages are
allocated but we can change the number of allocated pages by module parameter
fnic_fc_trace_max_page. Each entry is of 256 byte and available entries are
depends on allocated number of pages. We can turn on or off the fnic control
path trace functionality by module paramter fc_trace_enable and/or reset the
trace contain by module paramter fc_trace_clear.

Signed-off-by: Hiral Shah <hishah@cisco.com>
Signed-off-by: Sesidhar Baddela <sebaddel@cisco.com>
Signed-off-by: Christoph Hellwig <hch@lst.de>

1 files changed, 324 insertions, 2 deletions

diff --git a/drivers/scsi/fnic/fnic_trace.c b/drivers/scsi/fnic/fnic_trace.c
index e002e7187dc0..c77285926827 100644
--- a/drivers/scsi/fnic/fnic_trace.c
+++ b/drivers/scsi/fnic/fnic_trace.c
@@ -20,6 +20,7 @@
 #include <linux/errno.h>
 #include <linux/spinlock.h>
 #include <linux/kallsyms.h>
+#include <linux/time.h>
 #include "fnic_io.h"
 #include "fnic.h"
 
@@ -32,6 +33,16 @@ 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
  *
@@ -428,10 +439,10 @@ int fnic_trace_buf_init(void)
 	}
 	err = fnic_trace_debugfs_init();
 	if (err < 0) {
-		printk(KERN_ERR PFX "Failed to initialize debugfs for tracing\n");
+		pr_err("fnic: Failed to initialize debugfs for tracing\n");
 		goto err_fnic_trace_debugfs_init;
 	}
-	printk(KERN_INFO PFX "Successfully Initialized Trace Buffer\n");
+	pr_info("fnic: Successfully Initialized Trace Buffer\n");
 	return err;
 err_fnic_trace_debugfs_init:
 	fnic_trace_free();
@@ -456,3 +467,314 @@ void fnic_trace_free(void)
 	}
 	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: Reseting 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);
+		fc_trc_frame_len = fc_trc_frame_len + eth_fcoe_hdr_len;
+		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)));
+	} 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,
+		(fnic_fc_trace_max_pages * PAGE_SIZE * 3) - 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, (fnic_fc_trace_max_pages
+					* PAGE_SIZE * 3) - 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;
+}