[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;
+        }
+}