// SPDX-License-Identifier: GPL-2.0-only
/*
 * Copyright (c) 2005-2014 Brocade Communications Systems, Inc.
 * Copyright (c) 2014- QLogic Corporation.
 * All rights reserved
 * www.qlogic.com
 *
 * Linux driver for QLogic BR-series Fibre Channel Host Bus Adapter.
 */

#include <linux/debugfs.h>
#include <linux/export.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/pci_dev:<pci_name>
 * where the pci_name corresponds to the one under /sys/bus/pci/drivers/bfa
 *
 * Debugging service available per pci_dev:
 * 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_obj(struct bfad_debug_info);
        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_obj(struct bfad_debug_info);
        if (!fw_debug)
                return -ENOMEM;

        fw_debug->buffer_len = sizeof(struct bfa_trc_mod_s);

        fw_debug->debug_buffer = vzalloc(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;
        }

        spin_lock_irqsave(&bfad->bfad_lock, flags);
        rc = bfa_ioc_debug_fwtrc(&bfad->bfa.ioc,
                        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_obj(struct bfad_debug_info);
        if (!fw_debug)
                return -ENOMEM;

        fw_debug->buffer_len = sizeof(struct bfa_trc_mod_s);

        fw_debug->debug_buffer = vzalloc(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;
        }

        spin_lock_irqsave(&bfad->bfad_lock, flags);
        rc = bfa_ioc_debug_fwsave(&bfad->bfa.ioc,
                        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_obj(struct bfad_debug_info);
        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 = file->private_data;
        return fixed_size_llseek(file, offset, orig,
                                debug->buffer_len);
}

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 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)

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->ioc))
                        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 = simple_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, rc, i;
        u32 len;
        u32 *regbuf;
        void __iomem *rb, *reg_addr;
        unsigned long flags;
        void *kern_buf;

        kern_buf = memdup_user_nul(buf, nbytes);
        if (IS_ERR(kern_buf))
                return PTR_ERR(kern_buf);

        rc = sscanf(kern_buf, "%x:%x", &addr, &len);
        if (rc < 2 || len > (UINT_MAX >> 2)) {
                printk(KERN_INFO
                        "bfad[%d]: %s failed to read user buf\n",
                        bfad->inst_no, __func__);
                kfree(kern_buf);
                return -EINVAL;
        }

        kfree(kern_buf);
        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(ioc);

        /* 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 = readl(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;
        void *kern_buf;

        kern_buf = memdup_user_nul(buf, nbytes);
        if (IS_ERR(kern_buf))
                return PTR_ERR(kern_buf);

        rc = sscanf(kern_buf, "%x:%x", &addr, &val);
        if (rc < 2) {
                printk(KERN_INFO
                        "bfad[%d]: %s failed to read user buf\n",
                        bfad->inst_no, __func__);
                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 = 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 = (bfa_ioc_bar0(ioc)) + addr;
        spin_lock_irqsave(&bfad->bfad_lock, flags);
        writel(val, reg_addr);
        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;

        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;
        umode_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_s *bfad = port->bfad;
        const struct bfad_debugfs_entry *file;
        char name[64];
        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);
        }

        /* Setup the pci_dev debugfs directory for the port */
        snprintf(name, sizeof(name), "pci_dev:%s", bfad->pci_name);
        if (!port->port_debugfs_root) {
                port->port_debugfs_root =
                        debugfs_create_dir(name, bfa_debugfs_root);

                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);
                }
        }

        return;
}

inline void
bfad_debugfs_exit(struct bfad_port_s *port)
{
        struct bfad_s *bfad = 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 pci_dev debugfs directory for the 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;
        }
}