qib_fs.c

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/*
 * Copyright (c) 2012 Intel Corporation. All rights reserved.
 * Copyright (c) 2006 - 2012 QLogic Corporation. All rights reserved.
 * Copyright (c) 2006 PathScale, Inc. All rights reserved.
 *
 * This software is available to you under a choice of one of two
 * licenses.  You may choose to be licensed under the terms of the GNU
 * General Public License (GPL) Version 2, available from the file
 * COPYING in the main directory of this source tree, or the
 * OpenIB.org BSD license below:
 *
 *     Redistribution and use in source and binary forms, with or
 *     without modification, are permitted provided that the following
 *     conditions are met:
 *
 *      - Redistributions of source code must retain the above
 *        copyright notice, this list of conditions and the following
 *        disclaimer.
 *
 *      - Redistributions in binary form must reproduce the above
 *        copyright notice, this list of conditions and the following
 *        disclaimer in the documentation and/or other materials
 *        provided with the distribution.
 *
 * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND,
 * EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF
 * MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND
 * NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS
 * BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN
 * ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN
 * CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
 * SOFTWARE.
 */

#include <linux/module.h>
#include <linux/fs.h>
#include <linux/mount.h>
#include <linux/pagemap.h>
#include <linux/init.h>
#include <linux/namei.h>

#include "qib.h"

#define QIBFS_MAGIC 0x726a77

static struct super_block *qib_super;

#define private2dd(file) ((file)->f_dentry->d_inode->i_private)

static int qibfs_mknod(struct inode *dir, struct dentry *dentry,
               umode_t mode, const struct file_operations *fops,
               void *data)
{
    int error;
    struct inode *inode = new_inode(dir->i_sb);

    if (!inode) {
        error = -EPERM;
        goto bail;
    }

    inode->i_ino = get_next_ino();
    inode->i_mode = mode;
    inode->i_uid = GLOBAL_ROOT_UID;
    inode->i_gid = GLOBAL_ROOT_GID;
    inode->i_blocks = 0;
    inode->i_atime = CURRENT_TIME;
    inode->i_mtime = inode->i_atime;
    inode->i_ctime = inode->i_atime;
    inode->i_private = data;
    if (S_ISDIR(mode)) {
        inode->i_op = &simple_dir_inode_operations;
        inc_nlink(inode);
        inc_nlink(dir);
    }

    inode->i_fop = fops;

    d_instantiate(dentry, inode);
    error = 0;

bail:
    return error;
}

static int create_file(const char *name, umode_t mode,
               struct dentry *parent, struct dentry **dentry,
               const struct file_operations *fops, void *data)
{
    int error;

    *dentry = NULL;
    mutex_lock(&parent->d_inode->i_mutex);
    *dentry = lookup_one_len(name, parent, strlen(name));
    if (!IS_ERR(*dentry))
        error = qibfs_mknod(parent->d_inode, *dentry,
                    mode, fops, data);
    else
        error = PTR_ERR(*dentry);
    mutex_unlock(&parent->d_inode->i_mutex);

    return error;
}

static ssize_t driver_stats_read(struct file *file, char __user *buf,
                 size_t count, loff_t *ppos)
{
    return simple_read_from_buffer(buf, count, ppos, &qib_stats,
                       sizeof qib_stats);
}

/*
 * driver stats field names, one line per stat, single string.  Used by
 * programs like ipathstats to print the stats in a way which works for
 * different versions of drivers, without changing program source.
 * if qlogic_ib_stats changes, this needs to change.  Names need to be
 * 12 chars or less (w/o newline), for proper display by ipathstats utility.
 */
static const char qib_statnames[] =
    "KernIntr\n"
    "ErrorIntr\n"
    "Tx_Errs\n"
    "Rcv_Errs\n"
    "H/W_Errs\n"
    "NoPIOBufs\n"
    "CtxtsOpen\n"
    "RcvLen_Errs\n"
    "EgrBufFull\n"
    "EgrHdrFull\n"
    ;

static ssize_t driver_names_read(struct file *file, char __user *buf,
                 size_t count, loff_t *ppos)
{
    return simple_read_from_buffer(buf, count, ppos, qib_statnames,
        sizeof qib_statnames - 1); /* no null */
}

static const struct file_operations driver_ops[] = {
    { .read = driver_stats_read, .llseek = generic_file_llseek, },
    { .read = driver_names_read, .llseek = generic_file_llseek, },
};

/* read the per-device counters */
static ssize_t dev_counters_read(struct file *file, char __user *buf,
                 size_t count, loff_t *ppos)
{
    u64 *counters;
    size_t avail;
    struct qib_devdata *dd = private2dd(file);

    avail = dd->f_read_cntrs(dd, *ppos, NULL, &counters);
    return simple_read_from_buffer(buf, count, ppos, counters, avail);
}

/* read the per-device counters */
static ssize_t dev_names_read(struct file *file, char __user *buf,
                  size_t count, loff_t *ppos)
{
    char *names;
    size_t avail;
    struct qib_devdata *dd = private2dd(file);

    avail = dd->f_read_cntrs(dd, *ppos, &names, NULL);
    return simple_read_from_buffer(buf, count, ppos, names, avail);
}

static const struct file_operations cntr_ops[] = {
    { .read = dev_counters_read, .llseek = generic_file_llseek, },
    { .read = dev_names_read, .llseek = generic_file_llseek, },
};

/*
 * Could use file->f_dentry->d_inode->i_ino to figure out which file,
 * instead of separate routine for each, but for now, this works...
 */

/* read the per-port names (same for each port) */
static ssize_t portnames_read(struct file *file, char __user *buf,
                  size_t count, loff_t *ppos)
{
    char *names;
    size_t avail;
    struct qib_devdata *dd = private2dd(file);

    avail = dd->f_read_portcntrs(dd, *ppos, 0, &names, NULL);
    return simple_read_from_buffer(buf, count, ppos, names, avail);
}

/* read the per-port counters for port 1 (pidx 0) */
static ssize_t portcntrs_1_read(struct file *file, char __user *buf,
                size_t count, loff_t *ppos)
{
    u64 *counters;
    size_t avail;
    struct qib_devdata *dd = private2dd(file);

    avail = dd->f_read_portcntrs(dd, *ppos, 0, NULL, &counters);
    return simple_read_from_buffer(buf, count, ppos, counters, avail);
}

/* read the per-port counters for port 2 (pidx 1) */
static ssize_t portcntrs_2_read(struct file *file, char __user *buf,
                size_t count, loff_t *ppos)
{
    u64 *counters;
    size_t avail;
    struct qib_devdata *dd = private2dd(file);

    avail = dd->f_read_portcntrs(dd, *ppos, 1, NULL, &counters);
    return simple_read_from_buffer(buf, count, ppos, counters, avail);
}

static const struct file_operations portcntr_ops[] = {
    { .read = portnames_read, .llseek = generic_file_llseek, },
    { .read = portcntrs_1_read, .llseek = generic_file_llseek, },
    { .read = portcntrs_2_read, .llseek = generic_file_llseek, },
};

/*
 * read the per-port QSFP data for port 1 (pidx 0)
 */
static ssize_t qsfp_1_read(struct file *file, char __user *buf,
               size_t count, loff_t *ppos)
{
    struct qib_devdata *dd = private2dd(file);
    char *tmp;
    int ret;

    tmp = kmalloc(PAGE_SIZE, GFP_KERNEL);
    if (!tmp)
        return -ENOMEM;

    ret = qib_qsfp_dump(dd->pport, tmp, PAGE_SIZE);
    if (ret > 0)
        ret = simple_read_from_buffer(buf, count, ppos, tmp, ret);
    kfree(tmp);
    return ret;
}

/*
 * read the per-port QSFP data for port 2 (pidx 1)
 */
static ssize_t qsfp_2_read(struct file *file, char __user *buf,
               size_t count, loff_t *ppos)
{
    struct qib_devdata *dd = private2dd(file);
    char *tmp;
    int ret;

    if (dd->num_pports < 2)
        return -ENODEV;

    tmp = kmalloc(PAGE_SIZE, GFP_KERNEL);
    if (!tmp)
        return -ENOMEM;

    ret = qib_qsfp_dump(dd->pport + 1, tmp, PAGE_SIZE);
    if (ret > 0)
        ret = simple_read_from_buffer(buf, count, ppos, tmp, ret);
    kfree(tmp);
    return ret;
}

static const struct file_operations qsfp_ops[] = {
    { .read = qsfp_1_read, .llseek = generic_file_llseek, },
    { .read = qsfp_2_read, .llseek = generic_file_llseek, },
};

static ssize_t flash_read(struct file *file, char __user *buf,
              size_t count, loff_t *ppos)
{
    struct qib_devdata *dd;
    ssize_t ret;
    loff_t pos;
    char *tmp;

    pos = *ppos;

    if (pos < 0) {
        ret = -EINVAL;
        goto bail;
    }

    if (pos >= sizeof(struct qib_flash)) {
        ret = 0;
        goto bail;
    }

    if (count > sizeof(struct qib_flash) - pos)
        count = sizeof(struct qib_flash) - pos;

    tmp = kmalloc(count, GFP_KERNEL);
    if (!tmp) {
        ret = -ENOMEM;
        goto bail;
    }

    dd = private2dd(file);
    if (qib_eeprom_read(dd, pos, tmp, count)) {
        qib_dev_err(dd, "failed to read from flash\n");
        ret = -ENXIO;
        goto bail_tmp;
    }

    if (copy_to_user(buf, tmp, count)) {
        ret = -EFAULT;
        goto bail_tmp;
    }

    *ppos = pos + count;
    ret = count;

bail_tmp:
    kfree(tmp);

bail:
    return ret;
}

static ssize_t flash_write(struct file *file, const char __user *buf,
               size_t count, loff_t *ppos)
{
    struct qib_devdata *dd;
    ssize_t ret;
    loff_t pos;
    char *tmp;

    pos = *ppos;

    if (pos != 0) {
        ret = -EINVAL;
        goto bail;
    }

    if (count != sizeof(struct qib_flash)) {
        ret = -EINVAL;
        goto bail;
    }

    tmp = kmalloc(count, GFP_KERNEL);
    if (!tmp) {
        ret = -ENOMEM;
        goto bail;
    }

    if (copy_from_user(tmp, buf, count)) {
        ret = -EFAULT;
        goto bail_tmp;
    }

    dd = private2dd(file);
    if (qib_eeprom_write(dd, pos, tmp, count)) {
        ret = -ENXIO;
        qib_dev_err(dd, "failed to write to flash\n");
        goto bail_tmp;
    }

    *ppos = pos + count;
    ret = count;

bail_tmp:
    kfree(tmp);

bail:
    return ret;
}

static const struct file_operations flash_ops = {
    .read = flash_read,
    .write = flash_write,
    .llseek = default_llseek,
};

static int add_cntr_files(struct super_block *sb, struct qib_devdata *dd)
{
    struct dentry *dir, *tmp;
    char unit[10];
    int ret, i;

    /* create the per-unit directory */
    snprintf(unit, sizeof unit, "%u", dd->unit);
    ret = create_file(unit, S_IFDIR|S_IRUGO|S_IXUGO, sb->s_root, &dir,
              &simple_dir_operations, dd);
    if (ret) {
        pr_err("create_file(%s) failed: %d\n", unit, ret);
        goto bail;
    }

    /* create the files in the new directory */
    ret = create_file("counters", S_IFREG|S_IRUGO, dir, &tmp,
              &cntr_ops[0], dd);
    if (ret) {
        pr_err("create_file(%s/counters) failed: %d\n",
               unit, ret);
        goto bail;
    }
    ret = create_file("counter_names", S_IFREG|S_IRUGO, dir, &tmp,
              &cntr_ops[1], dd);
    if (ret) {
        pr_err("create_file(%s/counter_names) failed: %d\n",
               unit, ret);
        goto bail;
    }
    ret = create_file("portcounter_names", S_IFREG|S_IRUGO, dir, &tmp,
              &portcntr_ops[0], dd);
    if (ret) {
        pr_err("create_file(%s/%s) failed: %d\n",
               unit, "portcounter_names", ret);
        goto bail;
    }
    for (i = 1; i <= dd->num_pports; i++) {
        char fname[24];

        sprintf(fname, "port%dcounters", i);
        /* create the files in the new directory */
        ret = create_file(fname, S_IFREG|S_IRUGO, dir, &tmp,
                  &portcntr_ops[i], dd);
        if (ret) {
            pr_err("create_file(%s/%s) failed: %d\n",
                unit, fname, ret);
            goto bail;
        }
        if (!(dd->flags & QIB_HAS_QSFP))
            continue;
        sprintf(fname, "qsfp%d", i);
        ret = create_file(fname, S_IFREG|S_IRUGO, dir, &tmp,
                  &qsfp_ops[i - 1], dd);
        if (ret) {
            pr_err("create_file(%s/%s) failed: %d\n",
                unit, fname, ret);
            goto bail;
        }
    }

    ret = create_file("flash", S_IFREG|S_IWUSR|S_IRUGO, dir, &tmp,
              &flash_ops, dd);
    if (ret)
        pr_err("create_file(%s/flash) failed: %d\n",
            unit, ret);
bail:
    return ret;
}

static int remove_file(struct dentry *parent, char *name)
{
    struct dentry *tmp;
    int ret;

    tmp = lookup_one_len(name, parent, strlen(name));

    if (IS_ERR(tmp)) {
        ret = PTR_ERR(tmp);
        goto bail;
    }

    spin_lock(&tmp->d_lock);
    if (!(d_unhashed(tmp) && tmp->d_inode)) {
        dget_dlock(tmp);
        __d_drop(tmp);
        spin_unlock(&tmp->d_lock);
        simple_unlink(parent->d_inode, tmp);
    } else {
        spin_unlock(&tmp->d_lock);
    }

    ret = 0;
bail:
    /*
     * We don't expect clients to care about the return value, but
     * it's there if they need it.
     */
    return ret;
}

static int remove_device_files(struct super_block *sb,
                   struct qib_devdata *dd)
{
    struct dentry *dir, *root;
    char unit[10];
    int ret, i;

    root = dget(sb->s_root);
    mutex_lock(&root->d_inode->i_mutex);
    snprintf(unit, sizeof unit, "%u", dd->unit);
    dir = lookup_one_len(unit, root, strlen(unit));

    if (IS_ERR(dir)) {
        ret = PTR_ERR(dir);
        pr_err("Lookup of %s failed\n", unit);
        goto bail;
    }

    remove_file(dir, "counters");
    remove_file(dir, "counter_names");
    remove_file(dir, "portcounter_names");
    for (i = 0; i < dd->num_pports; i++) {
        char fname[24];

        sprintf(fname, "port%dcounters", i + 1);
        remove_file(dir, fname);
        if (dd->flags & QIB_HAS_QSFP) {
            sprintf(fname, "qsfp%d", i + 1);
            remove_file(dir, fname);
        }
    }
    remove_file(dir, "flash");
    d_delete(dir);
    ret = simple_rmdir(root->d_inode, dir);

bail:
    mutex_unlock(&root->d_inode->i_mutex);
    dput(root);
    return ret;
}

/*
 * This fills everything in when the fs is mounted, to handle umount/mount
 * after device init.  The direct add_cntr_files() call handles adding
 * them from the init code, when the fs is already mounted.
 */
static int qibfs_fill_super(struct super_block *sb, void *data, int silent)
{
    struct qib_devdata *dd, *tmp;
    unsigned long flags;
    int ret;

    static struct tree_descr files[] = {
        [2] = {"driver_stats", &driver_ops[0], S_IRUGO},
        [3] = {"driver_stats_names", &driver_ops[1], S_IRUGO},
        {""},
    };

    ret = simple_fill_super(sb, QIBFS_MAGIC, files);
    if (ret) {
        pr_err("simple_fill_super failed: %d\n", ret);
        goto bail;
    }

    spin_lock_irqsave(&qib_devs_lock, flags);

    list_for_each_entry_safe(dd, tmp, &qib_dev_list, list) {
        spin_unlock_irqrestore(&qib_devs_lock, flags);
        ret = add_cntr_files(sb, dd);
        if (ret)
            goto bail;
        spin_lock_irqsave(&qib_devs_lock, flags);
    }

    spin_unlock_irqrestore(&qib_devs_lock, flags);

bail:
    return ret;
}

static struct dentry *qibfs_mount(struct file_system_type *fs_type, int flags,
            const char *dev_name, void *data)
{
    struct dentry *ret;
    ret = mount_single(fs_type, flags, data, qibfs_fill_super);
    if (!IS_ERR(ret))
        qib_super = ret->d_sb;
    return ret;
}

static void qibfs_kill_super(struct super_block *s)
{
    kill_litter_super(s);
    qib_super = NULL;
}

int qibfs_add(struct qib_devdata *dd)
{
    int ret;

    /*
     * On first unit initialized, qib_super will not yet exist
     * because nobody has yet tried to mount the filesystem, so
     * we can't consider that to be an error; if an error occurs
     * during the mount, that will get a complaint, so this is OK.
     * add_cntr_files() for all units is done at mount from
     * qibfs_fill_super(), so one way or another, everything works.
     */
    if (qib_super == NULL)
        ret = 0;
    else
        ret = add_cntr_files(qib_super, dd);
    return ret;
}

int qibfs_remove(struct qib_devdata *dd)
{
    int ret = 0;

    if (qib_super)
        ret = remove_device_files(qib_super, dd);

    return ret;
}

static struct file_system_type qibfs_fs_type = {
    .owner =        THIS_MODULE,
    .name =         "ipathfs",
    .mount =        qibfs_mount,
    .kill_sb =      qibfs_kill_super,
};

int __init qib_init_qibfs(void)
{
    return register_filesystem(&qibfs_fs_type);
}

int __exit qib_exit_qibfs(void)
{
    return unregister_filesystem(&qibfs_fs_type);
}