bna: Add debugfs interface.

Change details:
	- Add debugfs support to obtain firmware trace, saved firmware trace on
	  an IOC crash, driver info and read/write to registers.

	- debugfs hierarchy:
	  bna/pci_dev:<pci_name>
	  where the pci_name corresponds to the one under /sys/bus/pci/drivers/bna

	- Following are the new debugfs entries added:
	  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.
	  drvinfo: collect the driver information.

Signed-off-by: Krishna Gudipati <kgudipat@brocade.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

1 files changed, 623 insertions, 0 deletions

diff --git a/drivers/net/ethernet/brocade/bna/bnad_debugfs.c b/drivers/net/ethernet/brocade/bna/bnad_debugfs.c
new file mode 100644
index 000000000000..592ad3929f53
--- /dev/null
+++ b/drivers/net/ethernet/brocade/bna/bnad_debugfs.c
@@ -0,0 +1,623 @@
+/*
+ * Linux network driver for Brocade Converged Network 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.
+ */
+/*
+ * Copyright (c) 2005-2011 Brocade Communications Systems, Inc.
+ * All rights reserved
+ * www.brocade.com
+ */
+
+#include <linux/debugfs.h>
+#include <linux/module.h>
+#include "bnad.h"
+
+/*
+ * BNA debufs interface
+ *
+ * To access the interface, debugfs file system should be mounted
+ * if not already mounted using:
+ *	mount -t debugfs none /sys/kernel/debug
+ *
+ * BNA Hierarchy:
+ *	- bna/pci_dev:<pci_name>
+ * where the pci_name corresponds to the one under /sys/bus/pci/drivers/bna
+ *
+ * Debugging service available per pci_dev:
+ *	fwtrc:  To collect current firmware 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 bnad_debug_info {
+	char *debug_buffer;
+	void *i_private;
+	int buffer_len;
+};
+
+static int
+bnad_debugfs_open_fwtrc(struct inode *inode, struct file *file)
+{
+	struct bnad *bnad = inode->i_private;
+	struct bnad_debug_info *fw_debug;
+	unsigned long flags;
+	int rc;
+
+	fw_debug = kzalloc(sizeof(struct bnad_debug_info), GFP_KERNEL);
+	if (!fw_debug)
+		return -ENOMEM;
+
+	fw_debug->buffer_len = BNA_DBG_FWTRC_LEN;
+
+	fw_debug->debug_buffer = kzalloc(fw_debug->buffer_len, GFP_KERNEL);
+	if (!fw_debug->debug_buffer) {
+		kfree(fw_debug);
+		fw_debug = NULL;
+		pr_warn("bna %s: Failed to allocate fwtrc buffer\n",
+			pci_name(bnad->pcidev));
+		return -ENOMEM;
+	}
+
+	spin_lock_irqsave(&bnad->bna_lock, flags);
+	rc = bfa_nw_ioc_debug_fwtrc(&bnad->bna.ioceth.ioc,
+			fw_debug->debug_buffer,
+			&fw_debug->buffer_len);
+	spin_unlock_irqrestore(&bnad->bna_lock, flags);
+	if (rc != BFA_STATUS_OK) {
+		kfree(fw_debug->debug_buffer);
+		fw_debug->debug_buffer = NULL;
+		kfree(fw_debug);
+		fw_debug = NULL;
+		pr_warn("bnad %s: Failed to collect fwtrc\n",
+			pci_name(bnad->pcidev));
+		return -ENOMEM;
+	}
+
+	file->private_data = fw_debug;
+
+	return 0;
+}
+
+static int
+bnad_debugfs_open_fwsave(struct inode *inode, struct file *file)
+{
+	struct bnad *bnad = inode->i_private;
+	struct bnad_debug_info *fw_debug;
+	unsigned long flags;
+	int rc;
+
+	fw_debug = kzalloc(sizeof(struct bnad_debug_info), GFP_KERNEL);
+	if (!fw_debug)
+		return -ENOMEM;
+
+	fw_debug->buffer_len = BNA_DBG_FWTRC_LEN;
+
+	fw_debug->debug_buffer = kzalloc(fw_debug->buffer_len, GFP_KERNEL);
+	if (!fw_debug->debug_buffer) {
+		kfree(fw_debug);
+		fw_debug = NULL;
+		pr_warn("bna %s: Failed to allocate fwsave buffer\n",
+			pci_name(bnad->pcidev));
+		return -ENOMEM;
+	}
+
+	spin_lock_irqsave(&bnad->bna_lock, flags);
+	rc = bfa_nw_ioc_debug_fwsave(&bnad->bna.ioceth.ioc,
+			fw_debug->debug_buffer,
+			&fw_debug->buffer_len);
+	spin_unlock_irqrestore(&bnad->bna_lock, flags);
+	if (rc != BFA_STATUS_OK && rc != BFA_STATUS_ENOFSAVE) {
+		kfree(fw_debug->debug_buffer);
+		fw_debug->debug_buffer = NULL;
+		kfree(fw_debug);
+		fw_debug = NULL;
+		pr_warn("bna %s: Failed to collect fwsave\n",
+			pci_name(bnad->pcidev));
+		return -ENOMEM;
+	}
+
+	file->private_data = fw_debug;
+
+	return 0;
+}
+
+static int
+bnad_debugfs_open_reg(struct inode *inode, struct file *file)
+{
+	struct bnad_debug_info *reg_debug;
+
+	reg_debug = kzalloc(sizeof(struct bnad_debug_info), GFP_KERNEL);
+	if (!reg_debug)
+		return -ENOMEM;
+
+	reg_debug->i_private = inode->i_private;
+
+	file->private_data = reg_debug;
+
+	return 0;
+}
+
+static int
+bnad_get_debug_drvinfo(struct bnad *bnad, void *buffer, u32 len)
+{
+	struct bnad_drvinfo *drvinfo = (struct bnad_drvinfo *) buffer;
+	struct bnad_iocmd_comp fcomp;
+	unsigned long flags = 0;
+	int ret = BFA_STATUS_FAILED;
+
+	/* Get IOC info */
+	spin_lock_irqsave(&bnad->bna_lock, flags);
+	bfa_nw_ioc_get_attr(&bnad->bna.ioceth.ioc, &drvinfo->ioc_attr);
+	spin_unlock_irqrestore(&bnad->bna_lock, flags);
+
+	/* Retrieve CEE related info */
+	fcomp.bnad = bnad;
+	fcomp.comp_status = 0;
+	init_completion(&fcomp.comp);
+	spin_lock_irqsave(&bnad->bna_lock, flags);
+	ret = bfa_nw_cee_get_attr(&bnad->bna.cee, &drvinfo->cee_attr,
+				bnad_cb_completion, &fcomp);
+	if (ret != BFA_STATUS_OK) {
+		spin_unlock_irqrestore(&bnad->bna_lock, flags);
+		goto out;
+	}
+	spin_unlock_irqrestore(&bnad->bna_lock, flags);
+	wait_for_completion(&fcomp.comp);
+	drvinfo->cee_status = fcomp.comp_status;
+
+	/* Retrieve flash partition info */
+	fcomp.comp_status = 0;
+	init_completion(&fcomp.comp);
+	spin_lock_irqsave(&bnad->bna_lock, flags);
+	ret = bfa_nw_flash_get_attr(&bnad->bna.flash, &drvinfo->flash_attr,
+				bnad_cb_completion, &fcomp);
+	if (ret != BFA_STATUS_OK) {
+		spin_unlock_irqrestore(&bnad->bna_lock, flags);
+		goto out;
+	}
+	spin_unlock_irqrestore(&bnad->bna_lock, flags);
+	wait_for_completion(&fcomp.comp);
+	drvinfo->flash_status = fcomp.comp_status;
+out:
+	return ret;
+}
+
+static int
+bnad_debugfs_open_drvinfo(struct inode *inode, struct file *file)
+{
+	struct bnad *bnad = inode->i_private;
+	struct bnad_debug_info *drv_info;
+	int rc;
+
+	drv_info = kzalloc(sizeof(struct bnad_debug_info), GFP_KERNEL);
+	if (!drv_info)
+		return -ENOMEM;
+
+	drv_info->buffer_len = sizeof(struct bnad_drvinfo);
+
+	drv_info->debug_buffer = kzalloc(drv_info->buffer_len, GFP_KERNEL);
+	if (!drv_info->debug_buffer) {
+		kfree(drv_info);
+		drv_info = NULL;
+		pr_warn("bna %s: Failed to allocate drv info buffer\n",
+			pci_name(bnad->pcidev));
+		return -ENOMEM;
+	}
+
+	mutex_lock(&bnad->conf_mutex);
+	rc = bnad_get_debug_drvinfo(bnad, drv_info->debug_buffer,
+				drv_info->buffer_len);
+	mutex_unlock(&bnad->conf_mutex);
+	if (rc != BFA_STATUS_OK) {
+		kfree(drv_info->debug_buffer);
+		drv_info->debug_buffer = NULL;
+		kfree(drv_info);
+		drv_info = NULL;
+		pr_warn("bna %s: Failed to collect drvinfo\n",
+			pci_name(bnad->pcidev));
+		return -ENOMEM;
+	}
+
+	file->private_data = drv_info;
+
+	return 0;
+}
+
+/* Changes the current file position */
+static loff_t
+bnad_debugfs_lseek(struct file *file, loff_t offset, int orig)
+{
+	loff_t pos = file->f_pos;
+	struct bnad_debug_info *debug = file->private_data;
+
+	if (!debug)
+		return -EINVAL;
+
+	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
+bnad_debugfs_read(struct file *file, char __user *buf,
+		  size_t nbytes, loff_t *pos)
+{
+	struct bnad_debug_info *debug = file->private_data;
+
+	if (!debug || !debug->debug_buffer)
+		return 0;
+
+	return simple_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(__ioc)	\
+	((u32)(bfa_asic_id_ctc(bfa_ioc_devid(__ioc)) ?  \
+	 BFA_REG_CT_ADDRSZ : BFA_REG_CB_ADDRSZ))
+#define BFA_REG_ADDRMSK(__ioc)	(BFA_REG_ADDRSZ(__ioc) - 1)
+
+/*
+ * Function to check if the register offset passed is valid.
+ */
+static int
+bna_reg_offset_check(struct bfa_ioc *ioc, 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(ioc))
+			return BFA_STATUS_EINVAL;
+	}
+	return BFA_STATUS_OK;
+}
+
+static ssize_t
+bnad_debugfs_read_regrd(struct file *file, char __user *buf,
+			size_t nbytes, loff_t *pos)
+{
+	struct bnad_debug_info *regrd_debug = file->private_data;
+	struct bnad *bnad = (struct bnad *)regrd_debug->i_private;
+	ssize_t rc;
+
+	if (!bnad->regdata)
+		return 0;
+
+	rc = simple_read_from_buffer(buf, nbytes, pos,
+			bnad->regdata, bnad->reglen);
+
+	if ((*pos + nbytes) >= bnad->reglen) {
+		kfree(bnad->regdata);
+		bnad->regdata = NULL;
+		bnad->reglen = 0;
+	}
+
+	return rc;
+}
+
+static ssize_t
+bnad_debugfs_write_regrd(struct file *file, const char __user *buf,
+		size_t nbytes, loff_t *ppos)
+{
+	struct bnad_debug_info *regrd_debug = file->private_data;
+	struct bnad *bnad = (struct bnad *)regrd_debug->i_private;
+	struct bfa_ioc *ioc = &bnad->bna.ioceth.ioc;
+	int addr, len, rc, i;
+	u32 *regbuf;
+	void __iomem *rb, *reg_addr;
+	unsigned long flags;
+	void *kern_buf;
+
+	/* Allocate memory to store the user space buf */
+	kern_buf = kzalloc(nbytes, GFP_KERNEL);
+	if (!kern_buf) {
+		pr_warn("bna %s: Failed to allocate user buffer\n",
+			pci_name(bnad->pcidev));
+		return -ENOMEM;
+	}
+
+	if (copy_from_user(kern_buf, (void  __user *)buf, nbytes)) {
+		kfree(kern_buf);
+		return -ENOMEM;
+	}
+
+	rc = sscanf(kern_buf, "%x:%x", &addr, &len);
+	if (rc < 2) {
+		pr_warn("bna %s: Failed to read user buffer\n",
+			pci_name(bnad->pcidev));
+		kfree(kern_buf);
+		return -EINVAL;
+	}
+
+	kfree(kern_buf);
+	kfree(bnad->regdata);
+	bnad->regdata = NULL;
+	bnad->reglen = 0;
+
+	bnad->regdata = kzalloc(len << 2, GFP_KERNEL);
+	if (!bnad->regdata) {
+		pr_warn("bna %s: Failed to allocate regrd buffer\n",
+			pci_name(bnad->pcidev));
+		return -ENOMEM;
+	}
+
+	bnad->reglen = len << 2;
+	rb = bfa_ioc_bar0(ioc);
+	addr &= BFA_REG_ADDRMSK(ioc);
+
+	/* offset and len sanity check */
+	rc = bna_reg_offset_check(ioc, addr, len);
+	if (rc) {
+		pr_warn("bna %s: Failed reg offset check\n",
+			pci_name(bnad->pcidev));
+		kfree(bnad->regdata);
+		bnad->regdata = NULL;
+		bnad->reglen = 0;
+		return -EINVAL;
+	}
+
+	reg_addr = rb + addr;
+	regbuf =  (u32 *)bnad->regdata;
+	spin_lock_irqsave(&bnad->bna_lock, flags);
+	for (i = 0; i < len; i++) {
+		*regbuf = readl(reg_addr);
+		regbuf++;
+		reg_addr += sizeof(u32);
+	}
+	spin_unlock_irqrestore(&bnad->bna_lock, flags);
+
+	return nbytes;
+}
+
+static ssize_t
+bnad_debugfs_write_regwr(struct file *file, const char __user *buf,
+		size_t nbytes, loff_t *ppos)
+{
+	struct bnad_debug_info *debug = file->private_data;
+	struct bnad *bnad = (struct bnad *)debug->i_private;
+	struct bfa_ioc *ioc = &bnad->bna.ioceth.ioc;
+	int addr, val, rc;
+	void __iomem *reg_addr;
+	unsigned long flags;
+	void *kern_buf;
+
+	/* Allocate memory to store the user space buf */
+	kern_buf = kzalloc(nbytes, GFP_KERNEL);
+	if (!kern_buf) {
+		pr_warn("bna %s: Failed to allocate user buffer\n",
+			pci_name(bnad->pcidev));
+		return -ENOMEM;
+	}
+
+	if (copy_from_user(kern_buf, (void  __user *)buf, nbytes)) {
+		kfree(kern_buf);
+		return -ENOMEM;
+	}
+
+	rc = sscanf(kern_buf, "%x:%x", &addr, &val);
+	if (rc < 2) {
+		pr_warn("bna %s: Failed to read user buffer\n",
+			pci_name(bnad->pcidev));
+		kfree(kern_buf);
+		return -EINVAL;
+	}
+	kfree(kern_buf);
+
+	addr &= BFA_REG_ADDRMSK(ioc); /* offset only 17 bit and word align */
+
+	/* offset and len sanity check */
+	rc = bna_reg_offset_check(ioc, addr, 1);
+	if (rc) {
+		pr_warn("bna %s: Failed reg offset check\n",
+			pci_name(bnad->pcidev));
+		return -EINVAL;
+	}
+
+	reg_addr = (bfa_ioc_bar0(ioc)) + addr;
+	spin_lock_irqsave(&bnad->bna_lock, flags);
+	writel(val, reg_addr);
+	spin_unlock_irqrestore(&bnad->bna_lock, flags);
+
+	return nbytes;
+}
+
+static int
+bnad_debugfs_release(struct inode *inode, struct file *file)
+{
+	struct bnad_debug_info *debug = file->private_data;
+
+	if (!debug)
+		return 0;
+
+	file->private_data = NULL;
+	kfree(debug);
+	return 0;
+}
+
+static int
+bnad_debugfs_buffer_release(struct inode *inode, struct file *file)
+{
+	struct bnad_debug_info *debug = file->private_data;
+
+	if (!debug)
+		return 0;
+
+	kfree(debug->debug_buffer);
+
+	file->private_data = NULL;
+	kfree(debug);
+	debug = NULL;
+	return 0;
+}
+
+static const struct file_operations bnad_debugfs_op_fwtrc = {
+	.owner		=	THIS_MODULE,
+	.open		=	bnad_debugfs_open_fwtrc,
+	.llseek		=	bnad_debugfs_lseek,
+	.read		=	bnad_debugfs_read,
+	.release	=	bnad_debugfs_buffer_release,
+};
+
+static const struct file_operations bnad_debugfs_op_fwsave = {
+	.owner		=	THIS_MODULE,
+	.open		=	bnad_debugfs_open_fwsave,
+	.llseek		=	bnad_debugfs_lseek,
+	.read		=	bnad_debugfs_read,
+	.release	=	bnad_debugfs_buffer_release,
+};
+
+static const struct file_operations bnad_debugfs_op_regrd = {
+	.owner		=       THIS_MODULE,
+	.open		=	bnad_debugfs_open_reg,
+	.llseek		=	bnad_debugfs_lseek,
+	.read		=	bnad_debugfs_read_regrd,
+	.write		=	bnad_debugfs_write_regrd,
+	.release	=	bnad_debugfs_release,
+};
+
+static const struct file_operations bnad_debugfs_op_regwr = {
+	.owner		=	THIS_MODULE,
+	.open		=	bnad_debugfs_open_reg,
+	.llseek		=	bnad_debugfs_lseek,
+	.write		=	bnad_debugfs_write_regwr,
+	.release	=	bnad_debugfs_release,
+};
+
+static const struct file_operations bnad_debugfs_op_drvinfo = {
+	.owner		=	THIS_MODULE,
+	.open		=	bnad_debugfs_open_drvinfo,
+	.llseek		=	bnad_debugfs_lseek,
+	.read		=	bnad_debugfs_read,
+	.release	=	bnad_debugfs_buffer_release,
+};
+
+struct bnad_debugfs_entry {
+	const char *name;
+	mode_t  mode;
+	const struct file_operations *fops;
+};
+
+static const struct bnad_debugfs_entry bnad_debugfs_files[] = {
+	{ "fwtrc",  S_IFREG|S_IRUGO, &bnad_debugfs_op_fwtrc, },
+	{ "fwsave", S_IFREG|S_IRUGO, &bnad_debugfs_op_fwsave, },
+	{ "regrd",  S_IFREG|S_IRUGO|S_IWUSR, &bnad_debugfs_op_regrd, },
+	{ "regwr",  S_IFREG|S_IWUSR, &bnad_debugfs_op_regwr, },
+	{ "drvinfo", S_IFREG|S_IRUGO, &bnad_debugfs_op_drvinfo, },
+};
+
+static struct dentry *bna_debugfs_root;
+static atomic_t bna_debugfs_port_count;
+
+/* Initialize debugfs interface for BNA */
+void
+bnad_debugfs_init(struct bnad *bnad)
+{
+	const struct bnad_debugfs_entry *file;
+	char name[64];
+	int i;
+
+	/* Setup the BNA debugfs root directory*/
+	if (!bna_debugfs_root) {
+		bna_debugfs_root = debugfs_create_dir("bna", NULL);
+		atomic_set(&bna_debugfs_port_count, 0);
+		if (!bna_debugfs_root) {
+			pr_warn("BNA: debugfs root dir creation failed\n");
+			return;
+		}
+	}
+
+	/* Setup the pci_dev debugfs directory for the port */
+	snprintf(name, sizeof(name), "pci_dev:%s", pci_name(bnad->pcidev));
+	if (!bnad->port_debugfs_root) {
+		bnad->port_debugfs_root =
+			debugfs_create_dir(name, bna_debugfs_root);
+		if (!bnad->port_debugfs_root) {
+			pr_warn("bna pci_dev %s: root dir creation failed\n",
+				pci_name(bnad->pcidev));
+			return;
+		}
+
+		atomic_inc(&bna_debugfs_port_count);
+
+		for (i = 0; i < ARRAY_SIZE(bnad_debugfs_files); i++) {
+			file = &bnad_debugfs_files[i];
+			bnad->bnad_dentry_files[i] =
+					debugfs_create_file(file->name,
+							file->mode,
+							bnad->port_debugfs_root,
+							bnad,
+							file->fops);
+			if (!bnad->bnad_dentry_files[i]) {
+				pr_warn(
+				     "BNA pci_dev:%s: create %s entry failed\n",
+				     pci_name(bnad->pcidev), file->name);
+				return;
+			}
+		}
+	}
+}
+
+/* Uninitialize debugfs interface for BNA */
+void
+bnad_debugfs_uninit(struct bnad *bnad)
+{
+	int i;
+
+	for (i = 0; i < ARRAY_SIZE(bnad_debugfs_files); i++) {
+		if (bnad->bnad_dentry_files[i]) {
+			debugfs_remove(bnad->bnad_dentry_files[i]);
+			bnad->bnad_dentry_files[i] = NULL;
+		}
+	}
+
+	/* Remove the pci_dev debugfs directory for the port */
+	if (bnad->port_debugfs_root) {
+		debugfs_remove(bnad->port_debugfs_root);
+		bnad->port_debugfs_root = NULL;
+		atomic_dec(&bna_debugfs_port_count);
+	}
+
+	/* Remove the BNA debugfs root directory */
+	if (atomic_read(&bna_debugfs_port_count) == 0) {
+		debugfs_remove(bna_debugfs_root);
+		bna_debugfs_root = NULL;
+	}
+}