[SCSI] bfa: add debugfs support

- Add debugfs support to obtain firmware trace, driver trace
  and read/write to registers.

- debugfs hierarchy:
  /sys/kernel/debug/bfa/host#
   where the host number corresponds to the one under /sys/class/scsi_host/host#

- Following are the new debugfs entries added:
  drvtrc: collect current driver trace
  fwtrc: collect current firmware trace.
  fwsave: collect last saved fw trace as a result of firmware crash.
  regwr: write one word to chip register
  regrd: read one or more words from chip register.

Signed-off-by: Jing Huang <huangj@brocade.com>
Signed-off-by: James Bottomley <James.Bottomley@suse.de>

1 files changed, 547 insertions, 0 deletions

diff --git a/drivers/scsi/bfa/bfad_debugfs.c b/drivers/scsi/bfa/bfad_debugfs.c
new file mode 100644
index 000000000000..4b82f12aad62
--- /dev/null
+++ b/drivers/scsi/bfa/bfad_debugfs.c
@@ -0,0 +1,547 @@
+/*
+ * Copyright (c) 2005-2010 Brocade Communications Systems, Inc.
+ * All rights reserved
+ * www.brocade.com
+ *
+ * Linux driver for Brocade Fibre Channel Host Bus Adapter.
+ *
+ * This program is free software; you can redistribute it and/or modify it
+ * under the terms of the GNU General Public License (GPL) Version 2 as
+ * published by the Free Software Foundation
+ *
+ * This program is distributed in the hope that it will be useful, but
+ * WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
+ * General Public License for more details.
+ */
+
+#include <linux/debugfs.h>
+
+#include <bfad_drv.h>
+#include <bfad_im.h>
+
+/*
+ * BFA debufs interface
+ *
+ * To access the interface, debugfs file system should be mounted
+ * if not already mounted using:
+ * mount -t debugfs none /sys/kernel/debug
+ *
+ * BFA Hierarchy:
+ * 	- bfa/host#
+ * where the host number corresponds to the one under /sys/class/scsi_host/host#
+ *
+ * Debugging service available per host:
+ * fwtrc:  To collect current firmware trace.
+ * drvtrc: To collect current driver trace
+ * fwsave: To collect last saved fw trace as a result of firmware crash.
+ * regwr:  To write one word to chip register
+ * regrd:  To read one or more words from chip register.
+ */
+
+struct bfad_debug_info {
+	char *debug_buffer;
+	void *i_private;
+	int buffer_len;
+};
+
+static int
+bfad_debugfs_open_drvtrc(struct inode *inode, struct file *file)
+{
+	struct bfad_port_s *port = inode->i_private;
+	struct bfad_s *bfad = port->bfad;
+	struct bfad_debug_info *debug;
+
+	debug = kzalloc(sizeof(struct bfad_debug_info), GFP_KERNEL);
+	if (!debug)
+		return -ENOMEM;
+
+	debug->debug_buffer = (void *) bfad->trcmod;
+	debug->buffer_len = sizeof(struct bfa_trc_mod_s);
+
+	file->private_data = debug;
+
+	return 0;
+}
+
+static int
+bfad_debugfs_open_fwtrc(struct inode *inode, struct file *file)
+{
+	struct bfad_port_s *port = inode->i_private;
+	struct bfad_s *bfad = port->bfad;
+	struct bfad_debug_info *fw_debug;
+	unsigned long flags;
+	int rc;
+
+	fw_debug = kzalloc(sizeof(struct bfad_debug_info), GFP_KERNEL);
+	if (!fw_debug)
+		return -ENOMEM;
+
+	fw_debug->buffer_len = sizeof(struct bfa_trc_mod_s);
+
+	fw_debug->debug_buffer = vmalloc(fw_debug->buffer_len);
+	if (!fw_debug->debug_buffer) {
+		kfree(fw_debug);
+		printk(KERN_INFO "bfad[%d]: Failed to allocate fwtrc buffer\n",
+				bfad->inst_no);
+		return -ENOMEM;
+	}
+
+	memset(fw_debug->debug_buffer, 0, fw_debug->buffer_len);
+
+	spin_lock_irqsave(&bfad->bfad_lock, flags);
+	rc = bfa_debug_fwtrc(&bfad->bfa,
+			fw_debug->debug_buffer,
+			&fw_debug->buffer_len);
+	spin_unlock_irqrestore(&bfad->bfad_lock, flags);
+	if (rc != BFA_STATUS_OK) {
+		vfree(fw_debug->debug_buffer);
+		fw_debug->debug_buffer = NULL;
+		kfree(fw_debug);
+		printk(KERN_INFO "bfad[%d]: Failed to collect fwtrc\n",
+				bfad->inst_no);
+		return -ENOMEM;
+	}
+
+	file->private_data = fw_debug;
+
+	return 0;
+}
+
+static int
+bfad_debugfs_open_fwsave(struct inode *inode, struct file *file)
+{
+	struct bfad_port_s *port = inode->i_private;
+	struct bfad_s *bfad = port->bfad;
+	struct bfad_debug_info *fw_debug;
+	unsigned long flags;
+	int rc;
+
+	fw_debug = kzalloc(sizeof(struct bfad_debug_info), GFP_KERNEL);
+	if (!fw_debug)
+		return -ENOMEM;
+
+	fw_debug->buffer_len = sizeof(struct bfa_trc_mod_s);
+
+	fw_debug->debug_buffer = vmalloc(fw_debug->buffer_len);
+	if (!fw_debug->debug_buffer) {
+		kfree(fw_debug);
+		printk(KERN_INFO "bfad[%d]: Failed to allocate fwsave buffer\n",
+				bfad->inst_no);
+		return -ENOMEM;
+	}
+
+	memset(fw_debug->debug_buffer, 0, fw_debug->buffer_len);
+
+	spin_lock_irqsave(&bfad->bfad_lock, flags);
+	rc = bfa_debug_fwsave(&bfad->bfa,
+			fw_debug->debug_buffer,
+			&fw_debug->buffer_len);
+	spin_unlock_irqrestore(&bfad->bfad_lock, flags);
+	if (rc != BFA_STATUS_OK) {
+		vfree(fw_debug->debug_buffer);
+		fw_debug->debug_buffer = NULL;
+		kfree(fw_debug);
+		printk(KERN_INFO "bfad[%d]: Failed to collect fwsave\n",
+				bfad->inst_no);
+		return -ENOMEM;
+	}
+
+	file->private_data = fw_debug;
+
+	return 0;
+}
+
+static int
+bfad_debugfs_open_reg(struct inode *inode, struct file *file)
+{
+	struct bfad_debug_info *reg_debug;
+
+	reg_debug = kzalloc(sizeof(struct bfad_debug_info), GFP_KERNEL);
+	if (!reg_debug)
+		return -ENOMEM;
+
+	reg_debug->i_private = inode->i_private;
+
+	file->private_data = reg_debug;
+
+	return 0;
+}
+
+/* Changes the current file position */
+static loff_t
+bfad_debugfs_lseek(struct file *file, loff_t offset, int orig)
+{
+	struct bfad_debug_info *debug;
+	loff_t pos = file->f_pos;
+
+	debug = file->private_data;
+
+	switch (orig) {
+	case 0:
+		file->f_pos = offset;
+		break;
+	case 1:
+		file->f_pos += offset;
+		break;
+	case 2:
+		file->f_pos = debug->buffer_len - offset;
+		break;
+	default:
+		return -EINVAL;
+	}
+
+	if (file->f_pos < 0 || file->f_pos > debug->buffer_len) {
+		file->f_pos = pos;
+		return -EINVAL;
+	}
+
+	return file->f_pos;
+}
+
+static ssize_t
+bfad_debugfs_read(struct file *file, char __user *buf,
+			size_t nbytes, loff_t *pos)
+{
+	struct bfad_debug_info *debug = file->private_data;
+
+	if (!debug || !debug->debug_buffer)
+		return 0;
+
+	return memory_read_from_buffer(buf, nbytes, pos,
+				debug->debug_buffer, debug->buffer_len);
+}
+
+#define BFA_REG_CT_ADDRSZ	(0x40000)
+#define BFA_REG_CB_ADDRSZ	(0x20000)
+#define BFA_REG_ADDRSZ(__bfa)	\
+	((bfa_ioc_devid(&(__bfa)->ioc) == BFA_PCI_DEVICE_ID_CT) ?	\
+		BFA_REG_CT_ADDRSZ : BFA_REG_CB_ADDRSZ)
+#define BFA_REG_ADDRMSK(__bfa)  ((uint32_t)(BFA_REG_ADDRSZ(__bfa) - 1))
+
+static bfa_status_t
+bfad_reg_offset_check(struct bfa_s *bfa, u32 offset, u32 len)
+{
+	u8	area;
+
+	/* check [16:15] */
+	area = (offset >> 15) & 0x7;
+	if (area == 0) {
+		/* PCIe core register */
+		if ((offset + (len<<2)) > 0x8000)    /* 8k dwords or 32KB */
+			return BFA_STATUS_EINVAL;
+	} else if (area == 0x1) {
+		/* CB 32 KB memory page */
+		if ((offset + (len<<2)) > 0x10000)    /* 8k dwords or 32KB */
+			return BFA_STATUS_EINVAL;
+	} else {
+		/* CB register space 64KB */
+		if ((offset + (len<<2)) > BFA_REG_ADDRMSK(bfa))
+			return BFA_STATUS_EINVAL;
+	}
+	return BFA_STATUS_OK;
+}
+
+static ssize_t
+bfad_debugfs_read_regrd(struct file *file, char __user *buf,
+		size_t nbytes, loff_t *pos)
+{
+	struct bfad_debug_info *regrd_debug = file->private_data;
+	struct bfad_port_s *port = (struct bfad_port_s *)regrd_debug->i_private;
+	struct bfad_s *bfad = port->bfad;
+	ssize_t rc;
+
+	if (!bfad->regdata)
+		return 0;
+
+	rc = memory_read_from_buffer(buf, nbytes, pos,
+			bfad->regdata, bfad->reglen);
+
+	if ((*pos + nbytes) >= bfad->reglen) {
+		kfree(bfad->regdata);
+		bfad->regdata = NULL;
+		bfad->reglen = 0;
+	}
+
+	return rc;
+}
+
+static ssize_t
+bfad_debugfs_write_regrd(struct file *file, const char __user *buf,
+		size_t nbytes, loff_t *ppos)
+{
+	struct bfad_debug_info *regrd_debug = file->private_data;
+	struct bfad_port_s *port = (struct bfad_port_s *)regrd_debug->i_private;
+	struct bfad_s *bfad = port->bfad;
+	struct bfa_s *bfa = &bfad->bfa;
+	struct bfa_ioc_s *ioc = &bfa->ioc;
+	int addr, len, rc, i;
+	u32 *regbuf;
+	void __iomem *rb, *reg_addr;
+	unsigned long flags;
+
+	rc = sscanf(buf, "%x:%x", &addr, &len);
+	if (rc < 2) {
+		printk(KERN_INFO
+			"bfad[%d]: %s failed to read user buf\n",
+			bfad->inst_no, __func__);
+		return -EINVAL;
+	}
+
+	kfree(bfad->regdata);
+	bfad->regdata = NULL;
+	bfad->reglen = 0;
+
+	bfad->regdata = kzalloc(len << 2, GFP_KERNEL);
+	if (!bfad->regdata) {
+		printk(KERN_INFO "bfad[%d]: Failed to allocate regrd buffer\n",
+				bfad->inst_no);
+		return -ENOMEM;
+	}
+
+	bfad->reglen = len << 2;
+	rb = bfa_ioc_bar0(ioc);
+	addr &= BFA_REG_ADDRMSK(bfa);
+
+	/* offset and len sanity check */
+	rc = bfad_reg_offset_check(bfa, addr, len);
+	if (rc) {
+		printk(KERN_INFO "bfad[%d]: Failed reg offset check\n",
+				bfad->inst_no);
+		kfree(bfad->regdata);
+		bfad->regdata = NULL;
+		bfad->reglen = 0;
+		return -EINVAL;
+	}
+
+	reg_addr = rb + addr;
+	regbuf =  (u32 *)bfad->regdata;
+	spin_lock_irqsave(&bfad->bfad_lock, flags);
+	for (i = 0; i < len; i++) {
+		*regbuf = bfa_reg_read(reg_addr);
+		regbuf++;
+		reg_addr += sizeof(u32);
+	}
+	spin_unlock_irqrestore(&bfad->bfad_lock, flags);
+
+	return nbytes;
+}
+
+static ssize_t
+bfad_debugfs_write_regwr(struct file *file, const char __user *buf,
+		size_t nbytes, loff_t *ppos)
+{
+	struct bfad_debug_info *debug = file->private_data;
+	struct bfad_port_s *port = (struct bfad_port_s *)debug->i_private;
+	struct bfad_s *bfad = port->bfad;
+	struct bfa_s *bfa = &bfad->bfa;
+	struct bfa_ioc_s *ioc = &bfa->ioc;
+	int addr, val, rc;
+	void __iomem *reg_addr;
+	unsigned long flags;
+
+	rc = sscanf(buf, "%x:%x", &addr, &val);
+	if (rc < 2) {
+		printk(KERN_INFO
+			"bfad[%d]: %s failed to read user buf\n",
+			bfad->inst_no, __func__);
+		return -EINVAL;
+	}
+
+	addr &= BFA_REG_ADDRMSK(bfa); /* offset only 17 bit and word align */
+
+	/* offset and len sanity check */
+	rc = bfad_reg_offset_check(bfa, addr, 1);
+	if (rc) {
+		printk(KERN_INFO
+			"bfad[%d]: Failed reg offset check\n",
+			bfad->inst_no);
+		return -EINVAL;
+	}
+
+	reg_addr = (uint32_t *) ((uint8_t *) bfa_ioc_bar0(ioc) + addr);
+	spin_lock_irqsave(&bfad->bfad_lock, flags);
+	bfa_reg_write(reg_addr, val);
+	spin_unlock_irqrestore(&bfad->bfad_lock, flags);
+
+	return nbytes;
+}
+
+static int
+bfad_debugfs_release(struct inode *inode, struct file *file)
+{
+	struct bfad_debug_info *debug = file->private_data;
+
+	if (!debug)
+		return 0;
+
+	file->private_data = NULL;
+	kfree(debug);
+	return 0;
+}
+
+static int
+bfad_debugfs_release_fwtrc(struct inode *inode, struct file *file)
+{
+	struct bfad_debug_info *fw_debug = file->private_data;
+
+	if (!fw_debug)
+		return 0;
+
+	if (fw_debug->debug_buffer)
+		vfree(fw_debug->debug_buffer);
+
+	file->private_data = NULL;
+	kfree(fw_debug);
+	return 0;
+}
+
+static const struct file_operations bfad_debugfs_op_drvtrc = {
+	.owner		=	THIS_MODULE,
+	.open		=	bfad_debugfs_open_drvtrc,
+	.llseek		=	bfad_debugfs_lseek,
+	.read		=	bfad_debugfs_read,
+	.release	=	bfad_debugfs_release,
+};
+
+static const struct file_operations bfad_debugfs_op_fwtrc = {
+	.owner		=	THIS_MODULE,
+	.open		=	bfad_debugfs_open_fwtrc,
+	.llseek		=	bfad_debugfs_lseek,
+	.read		=	bfad_debugfs_read,
+	.release	=	bfad_debugfs_release_fwtrc,
+};
+
+static const struct file_operations bfad_debugfs_op_fwsave = {
+	.owner		=	THIS_MODULE,
+	.open		=	bfad_debugfs_open_fwsave,
+	.llseek		=	bfad_debugfs_lseek,
+	.read		=	bfad_debugfs_read,
+	.release	=	bfad_debugfs_release_fwtrc,
+};
+
+static const struct file_operations bfad_debugfs_op_regrd = {
+	.owner		=	THIS_MODULE,
+	.open		=	bfad_debugfs_open_reg,
+	.llseek		=	bfad_debugfs_lseek,
+	.read		=	bfad_debugfs_read_regrd,
+	.write		=	bfad_debugfs_write_regrd,
+	.release	=	bfad_debugfs_release,
+};
+
+static const struct file_operations bfad_debugfs_op_regwr = {
+	.owner		=	THIS_MODULE,
+	.open		=	bfad_debugfs_open_reg,
+	.llseek		=	bfad_debugfs_lseek,
+	.write		=	bfad_debugfs_write_regwr,
+	.release	=	bfad_debugfs_release,
+};
+
+struct bfad_debugfs_entry {
+	const char *name;
+	mode_t	mode;
+	const struct file_operations *fops;
+};
+
+static const struct bfad_debugfs_entry bfad_debugfs_files[] = {
+	{ "drvtrc", S_IFREG|S_IRUGO, &bfad_debugfs_op_drvtrc, },
+	{ "fwtrc",  S_IFREG|S_IRUGO, &bfad_debugfs_op_fwtrc,  },
+	{ "fwsave", S_IFREG|S_IRUGO, &bfad_debugfs_op_fwsave, },
+	{ "regrd",  S_IFREG|S_IRUGO|S_IWUSR, &bfad_debugfs_op_regrd,  },
+	{ "regwr",  S_IFREG|S_IWUSR, &bfad_debugfs_op_regwr,  },
+};
+
+static struct dentry *bfa_debugfs_root;
+static atomic_t bfa_debugfs_port_count;
+
+inline void
+bfad_debugfs_init(struct bfad_port_s *port)
+{
+	struct bfad_im_port_s *im_port = port->im_port;
+	struct bfad_s *bfad = im_port->bfad;
+	struct Scsi_Host *shost = im_port->shost;
+	const struct bfad_debugfs_entry *file;
+	char name[16];
+	int i;
+
+	if (!bfa_debugfs_enable)
+		return;
+
+	/* Setup the BFA debugfs root directory*/
+	if (!bfa_debugfs_root) {
+		bfa_debugfs_root = debugfs_create_dir("bfa", NULL);
+		atomic_set(&bfa_debugfs_port_count, 0);
+		if (!bfa_debugfs_root) {
+			printk(KERN_WARNING
+				"BFA debugfs root dir creation failed\n");
+			goto err;
+		}
+	}
+
+	/*
+	 * Setup the host# directory for the port,
+	 * corresponds to the scsi_host num of this port.
+	 */
+	snprintf(name, sizeof(name), "host%d", shost->host_no);
+	if (!port->port_debugfs_root) {
+		port->port_debugfs_root =
+			debugfs_create_dir(name, bfa_debugfs_root);
+		if (!port->port_debugfs_root) {
+			printk(KERN_WARNING
+				"BFA host root dir creation failed\n");
+			goto err;
+		}
+
+		atomic_inc(&bfa_debugfs_port_count);
+
+		for (i = 0; i < ARRAY_SIZE(bfad_debugfs_files); i++) {
+			file = &bfad_debugfs_files[i];
+			bfad->bfad_dentry_files[i] =
+					debugfs_create_file(file->name,
+							file->mode,
+							port->port_debugfs_root,
+							port,
+							file->fops);
+			if (!bfad->bfad_dentry_files[i]) {
+				printk(KERN_WARNING
+					"BFA host%d: create %s entry failed\n",
+					shost->host_no, file->name);
+				goto err;
+			}
+		}
+	}
+
+err:
+	return;
+}
+
+inline void
+bfad_debugfs_exit(struct bfad_port_s *port)
+{
+	struct bfad_im_port_s *im_port = port->im_port;
+	struct bfad_s *bfad = im_port->bfad;
+	int i;
+
+	for (i = 0; i < ARRAY_SIZE(bfad_debugfs_files); i++) {
+		if (bfad->bfad_dentry_files[i]) {
+			debugfs_remove(bfad->bfad_dentry_files[i]);
+			bfad->bfad_dentry_files[i] = NULL;
+		}
+	}
+
+	/*
+	 * Remove the host# directory for the port,
+	 * corresponds to the scsi_host num of this port.
+	*/
+	if (port->port_debugfs_root) {
+		debugfs_remove(port->port_debugfs_root);
+		port->port_debugfs_root = NULL;
+		atomic_dec(&bfa_debugfs_port_count);
+	}
+
+	/* Remove the BFA debugfs root directory */
+	if (atomic_read(&bfa_debugfs_port_count) == 0) {
+		debugfs_remove(bfa_debugfs_root);
+		bfa_debugfs_root = NULL;
+	}
+}