[PATCH] r/o bind mount prepwork: inc_nlink() helper

[linux-2.6.git] / drivers / infiniband / hw / ipath / ipath_fs.c

/*
 * Copyright (c) 2006 QLogic, Inc. 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/version.h>
#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 <linux/pci.h>

#include "ipath_kernel.h"

#define IPATHFS_MAGIC 0x726a77

static struct super_block *ipath_super;

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

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

        inode->i_mode = mode;
        inode->i_uid = 0;
        inode->i_gid = 0;
        inode->i_blocks = 0;
        inode->i_atime = inode->i_mtime = inode->i_ctime = CURRENT_TIME;
        inode->i_private = data;
        if ((mode & S_IFMT) == S_IFDIR) {
                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, mode_t mode,
                       struct dentry *parent, struct dentry **dentry,
                       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 = ipathfs_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 atomic_stats_read(struct file *file, char __user *buf,
                                 size_t count, loff_t *ppos)
{
        return simple_read_from_buffer(buf, count, ppos, &ipath_stats,
                                       sizeof ipath_stats);
}

static struct file_operations atomic_stats_ops = {
        .read = atomic_stats_read,
};

#define NUM_COUNTERS sizeof(struct infinipath_counters) / sizeof(u64)

static ssize_t atomic_counters_read(struct file *file, char __user *buf,
                                    size_t count, loff_t *ppos)
{
        u64 counters[NUM_COUNTERS];
        u16 i;
        struct ipath_devdata *dd;

        dd = file->f_dentry->d_inode->i_private;

        for (i = 0; i < NUM_COUNTERS; i++)
                counters[i] = ipath_snap_cntr(dd, i);

        return simple_read_from_buffer(buf, count, ppos, counters,
                                       sizeof counters);
}

static struct file_operations atomic_counters_ops = {
        .read = atomic_counters_read,
};

static ssize_t atomic_node_info_read(struct file *file, char __user *buf,
                                     size_t count, loff_t *ppos)
{
        u32 nodeinfo[10];
        struct ipath_devdata *dd;
        u64 guid;

        dd = file->f_dentry->d_inode->i_private;

        guid = be64_to_cpu(dd->ipath_guid);

        nodeinfo[0] =                   /* BaseVersion is SMA */
                /* ClassVersion is SMA */
                (1 << 8)                /* NodeType  */
                | (1 << 0);             /* NumPorts */
        nodeinfo[1] = (u32) (guid >> 32);
        nodeinfo[2] = (u32) (guid & 0xffffffff);
        /* PortGUID == SystemImageGUID for us */
        nodeinfo[3] = nodeinfo[1];
        /* PortGUID == SystemImageGUID for us */
        nodeinfo[4] = nodeinfo[2];
        /* PortGUID == NodeGUID for us */
        nodeinfo[5] = nodeinfo[3];
        /* PortGUID == NodeGUID for us */
        nodeinfo[6] = nodeinfo[4];
        nodeinfo[7] = (4 << 16) /* we support 4 pkeys */
                | (dd->ipath_deviceid << 0);
        /* our chip version as 16 bits major, 16 bits minor */
        nodeinfo[8] = dd->ipath_minrev | (dd->ipath_majrev << 16);
        nodeinfo[9] = (dd->ipath_unit << 24) | (dd->ipath_vendorid << 0);

        return simple_read_from_buffer(buf, count, ppos, nodeinfo,
                                       sizeof nodeinfo);
}

static struct file_operations atomic_node_info_ops = {
        .read = atomic_node_info_read,
};

static ssize_t atomic_port_info_read(struct file *file, char __user *buf,
                                     size_t count, loff_t *ppos)
{
        u32 portinfo[13];
        u32 tmp, tmp2;
        struct ipath_devdata *dd;

        dd = file->f_dentry->d_inode->i_private;

        /* so we only initialize non-zero fields. */
        memset(portinfo, 0, sizeof portinfo);

        /*
         * Notimpl yet M_Key (64)
         * Notimpl yet GID (64)
         */

        portinfo[4] = (dd->ipath_lid << 16);

        /*
         * Notimpl yet SMLID.
         * CapabilityMask is 0, we don't support any of these
         * DiagCode is 0; we don't store any diag info for now Notimpl yet
         * M_KeyLeasePeriod (we don't support M_Key)
         */

        /* LocalPortNum is whichever port number they ask for */
        portinfo[7] = (dd->ipath_unit << 24)
                /* LinkWidthEnabled */
                | (2 << 16)
                /* LinkWidthSupported (really 2, but not IB valid) */
                | (3 << 8)
                /* LinkWidthActive */
                | (2 << 0);
        tmp = dd->ipath_lastibcstat & IPATH_IBSTATE_MASK;
        tmp2 = 5;
        if (tmp == IPATH_IBSTATE_INIT)
                tmp = 2;
        else if (tmp == IPATH_IBSTATE_ARM)
                tmp = 3;
        else if (tmp == IPATH_IBSTATE_ACTIVE)
                tmp = 4;
        else {
                tmp = 0;        /* down */
                tmp2 = tmp & 0xf;
        }

        portinfo[8] = (1 << 28) /* LinkSpeedSupported */
                | (tmp << 24)   /* PortState */
                | (tmp2 << 20)  /* PortPhysicalState */
                | (2 << 16)

                /* LinkDownDefaultState */
                /* M_KeyProtectBits == 0 */
                /* NotImpl yet LMC == 0 (we can support all values) */
                | (1 << 4)      /* LinkSpeedActive */
                | (1 << 0);     /* LinkSpeedEnabled */
        switch (dd->ipath_ibmtu) {
        case 4096:
                tmp = 5;
                break;
        case 2048:
                tmp = 4;
                break;
        case 1024:
                tmp = 3;
                break;
        case 512:
                tmp = 2;
                break;
        case 256:
                tmp = 1;
                break;
        default:                /* oops, something is wrong */
                ipath_dbg("Problem, ipath_ibmtu 0x%x not a valid IB MTU, "
                          "treat as 2048\n", dd->ipath_ibmtu);
                tmp = 4;
                break;
        }
        portinfo[9] = (tmp << 28)
                /* NeighborMTU */
                /* Notimpl MasterSMSL */
                | (1 << 20)

                /* VLCap */
                /* Notimpl InitType (actually, an SMA decision) */
                /* VLHighLimit is 0 (only one VL) */
                ; /* VLArbitrationHighCap is 0 (only one VL) */
        portinfo[10] =  /* VLArbitrationLowCap is 0 (only one VL) */
                /* InitTypeReply is SMA decision */
                (5 << 16)       /* MTUCap 4096 */
                | (7 << 13)     /* VLStallCount */
                | (0x1f << 8)   /* HOQLife */
                | (1 << 4)

                /* OperationalVLs 0 */
                /* PartitionEnforcementInbound */
                /* PartitionEnforcementOutbound not enforced */
                /* FilterRawinbound not enforced */
                ;               /* FilterRawOutbound not enforced */
        /* M_KeyViolations are not counted by hardware, SMA can count */
        tmp = ipath_read_creg32(dd, dd->ipath_cregs->cr_errpkey);
        /* P_KeyViolations are counted by hardware. */
        portinfo[11] = ((tmp & 0xffff) << 0);
        portinfo[12] =
                /* Q_KeyViolations are not counted by hardware */
                (1 << 8)

                /* GUIDCap */
                /* SubnetTimeOut handled by SMA */
                /* RespTimeValue handled by SMA */
                ;
        /* LocalPhyErrors are programmed to max */
        portinfo[12] |= (0xf << 20)
                | (0xf << 16)   /* OverRunErrors are programmed to max */
                ;

        return simple_read_from_buffer(buf, count, ppos, portinfo,
                                       sizeof portinfo);
}

static struct file_operations atomic_port_info_ops = {
        .read = atomic_port_info_read,
};

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

        pos = *ppos;

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

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

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

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

        dd = file->f_dentry->d_inode->i_private;
        if (ipath_eeprom_read(dd, pos, tmp, count)) {
                ipath_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 ipath_devdata *dd;
        ssize_t ret;
        loff_t pos;
        char *tmp;

        pos = *ppos;

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

        if (count != sizeof(struct ipath_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 = file->f_dentry->d_inode->i_private;
        if (ipath_eeprom_write(dd, pos, tmp, count)) {
                ret = -ENXIO;
                ipath_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 struct file_operations flash_ops = {
        .read = flash_read,
        .write = flash_write,
};

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

        snprintf(unit, sizeof unit, "%02d", dd->ipath_unit);
        ret = create_file(unit, S_IFDIR|S_IRUGO|S_IXUGO, sb->s_root, &dir,
                          (struct file_operations *) &simple_dir_operations,
                          dd);
        if (ret) {
                printk(KERN_ERR "create_file(%s) failed: %d\n", unit, ret);
                goto bail;
        }

        ret = create_file("atomic_counters", S_IFREG|S_IRUGO, dir, &tmp,
                          &atomic_counters_ops, dd);
        if (ret) {
                printk(KERN_ERR "create_file(%s/atomic_counters) "
                       "failed: %d\n", unit, ret);
                goto bail;
        }

        ret = create_file("node_info", S_IFREG|S_IRUGO, dir, &tmp,
                          &atomic_node_info_ops, dd);
        if (ret) {
                printk(KERN_ERR "create_file(%s/node_info) "
                       "failed: %d\n", unit, ret);
                goto bail;
        }

        ret = create_file("port_info", S_IFREG|S_IRUGO, dir, &tmp,
                          &atomic_port_info_ops, dd);
        if (ret) {
                printk(KERN_ERR "create_file(%s/port_info) "
                       "failed: %d\n", unit, ret);
                goto bail;
        }

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

bail:
        return ret;
}

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

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

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

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

        root = dget(sb->s_root);
        mutex_lock(&root->d_inode->i_mutex);
        snprintf(unit, sizeof unit, "%02d", dd->ipath_unit);
        dir = lookup_one_len(unit, root, strlen(unit));

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

        remove_file(dir, "flash");
        remove_file(dir, "port_info");
        remove_file(dir, "node_info");
        remove_file(dir, "atomic_counters");
        d_delete(dir);
        ret = simple_rmdir(root->d_inode, dir);

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

static int ipathfs_fill_super(struct super_block *sb, void *data,
                              int silent)
{
        struct ipath_devdata *dd, *tmp;
        unsigned long flags;
        int ret;

        static struct tree_descr files[] = {
                [1] = {"atomic_stats", &atomic_stats_ops, S_IRUGO},
                {""},
        };

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

        spin_lock_irqsave(&ipath_devs_lock, flags);

        list_for_each_entry_safe(dd, tmp, &ipath_dev_list, ipath_list) {
                spin_unlock_irqrestore(&ipath_devs_lock, flags);
                ret = create_device_files(sb, dd);
                if (ret) {
                        deactivate_super(sb);
                        goto bail;
                }
                spin_lock_irqsave(&ipath_devs_lock, flags);
        }

        spin_unlock_irqrestore(&ipath_devs_lock, flags);

bail:
        return ret;
}

static int ipathfs_get_sb(struct file_system_type *fs_type, int flags,
                        const char *dev_name, void *data, struct vfsmount *mnt)
{
        int ret = get_sb_single(fs_type, flags, data,
                                    ipathfs_fill_super, mnt);
        if (ret >= 0)
                ipath_super = mnt->mnt_sb;
        return ret;
}

static void ipathfs_kill_super(struct super_block *s)
{
        kill_litter_super(s);
        ipath_super = NULL;
}

int ipathfs_add_device(struct ipath_devdata *dd)
{
        int ret;

        if (ipath_super == NULL) {
                ret = 0;
                goto bail;
        }

        ret = create_device_files(ipath_super, dd);

bail:
        return ret;
}

int ipathfs_remove_device(struct ipath_devdata *dd)
{
        int ret;

        if (ipath_super == NULL) {
                ret = 0;
                goto bail;
        }

        ret = remove_device_files(ipath_super, dd);

bail:
        return ret;
}

static struct file_system_type ipathfs_fs_type = {
        .owner =        THIS_MODULE,
        .name =         "ipathfs",
        .get_sb =       ipathfs_get_sb,
        .kill_sb =      ipathfs_kill_super,
};

int __init ipath_init_ipathfs(void)
{
        return register_filesystem(&ipathfs_fs_type);
}

void __exit ipath_exit_ipathfs(void)
{
        unregister_filesystem(&ipathfs_fs_type);
}