ps3flash.c

Go to the documentation of this file.

/*
 * PS3 FLASH ROM Storage Driver
 *
 * Copyright (C) 2007 Sony Computer Entertainment Inc.
 * Copyright 2007 Sony Corp.
 *
 * This program is free software; you can redistribute it and/or modify it
 * under the terms of the GNU General Public License as published
 * by the Free Software Foundation; version 2 of the License.
 *
 * 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.
 *
 * You should have received a copy of the GNU General Public License along
 * with this program; if not, write to the Free Software Foundation, Inc.,
 * 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA.
 */

#include <linux/fs.h>
#include <linux/miscdevice.h>
#include <linux/slab.h>
#include <linux/uaccess.h>
#include <linux/module.h>

#include <asm/lv1call.h>
#include <asm/ps3stor.h>


#define DEVICE_NAME     "ps3flash"

#define FLASH_BLOCK_SIZE    (256*1024)


struct ps3flash_private {
    struct mutex mutex; /* Bounce buffer mutex */
    u64 chunk_sectors;
    int tag;        /* Start sector of buffer, -1 if invalid */
    bool dirty;
};

static struct ps3_storage_device *ps3flash_dev;

static int ps3flash_read_write_sectors(struct ps3_storage_device *dev,
                       u64 start_sector, int write)
{
    struct ps3flash_private *priv = ps3_system_bus_get_drvdata(&dev->sbd);
    u64 res = ps3stor_read_write_sectors(dev, dev->bounce_lpar,
                         start_sector, priv->chunk_sectors,
                         write);
    if (res) {
        dev_err(&dev->sbd.core, "%s:%u: %s failed 0x%llx\n", __func__,
            __LINE__, write ? "write" : "read", res);
        return -EIO;
    }
    return 0;
}

static int ps3flash_writeback(struct ps3_storage_device *dev)
{
    struct ps3flash_private *priv = ps3_system_bus_get_drvdata(&dev->sbd);
    int res;

    if (!priv->dirty || priv->tag < 0)
        return 0;

    res = ps3flash_read_write_sectors(dev, priv->tag, 1);
    if (res)
        return res;

    priv->dirty = false;
    return 0;
}

static int ps3flash_fetch(struct ps3_storage_device *dev, u64 start_sector)
{
    struct ps3flash_private *priv = ps3_system_bus_get_drvdata(&dev->sbd);
    int res;

    if (start_sector == priv->tag)
        return 0;

    res = ps3flash_writeback(dev);
    if (res)
        return res;

    priv->tag = -1;

    res = ps3flash_read_write_sectors(dev, start_sector, 0);
    if (res)
        return res;

    priv->tag = start_sector;
    return 0;
}

static loff_t ps3flash_llseek(struct file *file, loff_t offset, int origin)
{
    struct ps3_storage_device *dev = ps3flash_dev;
    loff_t res;

    mutex_lock(&file->f_mapping->host->i_mutex);
    switch (origin) {
    case 0:
        break;
    case 1:
        offset += file->f_pos;
        break;
    case 2:
        offset += dev->regions[dev->region_idx].size*dev->blk_size;
        break;
    default:
        offset = -1;
    }
    if (offset < 0) {
        res = -EINVAL;
        goto out;
    }

    file->f_pos = offset;
    res = file->f_pos;

out:
    mutex_unlock(&file->f_mapping->host->i_mutex);
    return res;
}

static ssize_t ps3flash_read(char __user *userbuf, void *kernelbuf,
                 size_t count, loff_t *pos)
{
    struct ps3_storage_device *dev = ps3flash_dev;
    struct ps3flash_private *priv = ps3_system_bus_get_drvdata(&dev->sbd);
    u64 size, sector, offset;
    int res;
    size_t remaining, n;
    const void *src;

    dev_dbg(&dev->sbd.core,
        "%s:%u: Reading %zu bytes at position %lld to U0x%p/K0x%p\n",
        __func__, __LINE__, count, *pos, userbuf, kernelbuf);

    size = dev->regions[dev->region_idx].size*dev->blk_size;
    if (*pos >= size || !count)
        return 0;

    if (*pos + count > size) {
        dev_dbg(&dev->sbd.core,
            "%s:%u Truncating count from %zu to %llu\n", __func__,
            __LINE__, count, size - *pos);
        count = size - *pos;
    }

    sector = *pos / dev->bounce_size * priv->chunk_sectors;
    offset = *pos % dev->bounce_size;

    remaining = count;
    do {
        n = min_t(u64, remaining, dev->bounce_size - offset);
        src = dev->bounce_buf + offset;

        mutex_lock(&priv->mutex);

        res = ps3flash_fetch(dev, sector);
        if (res)
            goto fail;

        dev_dbg(&dev->sbd.core,
            "%s:%u: copy %lu bytes from 0x%p to U0x%p/K0x%p\n",
            __func__, __LINE__, n, src, userbuf, kernelbuf);
        if (userbuf) {
            if (copy_to_user(userbuf, src, n)) {
                res = -EFAULT;
                goto fail;
            }
            userbuf += n;
        }
        if (kernelbuf) {
            memcpy(kernelbuf, src, n);
            kernelbuf += n;
        }

        mutex_unlock(&priv->mutex);

        *pos += n;
        remaining -= n;
        sector += priv->chunk_sectors;
        offset = 0;
    } while (remaining > 0);

    return count;

fail:
    mutex_unlock(&priv->mutex);
    return res;
}

static ssize_t ps3flash_write(const char __user *userbuf,
                  const void *kernelbuf, size_t count, loff_t *pos)
{
    struct ps3_storage_device *dev = ps3flash_dev;
    struct ps3flash_private *priv = ps3_system_bus_get_drvdata(&dev->sbd);
    u64 size, sector, offset;
    int res = 0;
    size_t remaining, n;
    void *dst;

    dev_dbg(&dev->sbd.core,
        "%s:%u: Writing %zu bytes at position %lld from U0x%p/K0x%p\n",
        __func__, __LINE__, count, *pos, userbuf, kernelbuf);

    size = dev->regions[dev->region_idx].size*dev->blk_size;
    if (*pos >= size || !count)
        return 0;

    if (*pos + count > size) {
        dev_dbg(&dev->sbd.core,
            "%s:%u Truncating count from %zu to %llu\n", __func__,
            __LINE__, count, size - *pos);
        count = size - *pos;
    }

    sector = *pos / dev->bounce_size * priv->chunk_sectors;
    offset = *pos % dev->bounce_size;

    remaining = count;
    do {
        n = min_t(u64, remaining, dev->bounce_size - offset);
        dst = dev->bounce_buf + offset;

        mutex_lock(&priv->mutex);

        if (n != dev->bounce_size)
            res = ps3flash_fetch(dev, sector);
        else if (sector != priv->tag)
            res = ps3flash_writeback(dev);
        if (res)
            goto fail;

        dev_dbg(&dev->sbd.core,
            "%s:%u: copy %lu bytes from U0x%p/K0x%p to 0x%p\n",
            __func__, __LINE__, n, userbuf, kernelbuf, dst);
        if (userbuf) {
            if (copy_from_user(dst, userbuf, n)) {
                res = -EFAULT;
                goto fail;
            }
            userbuf += n;
        }
        if (kernelbuf) {
            memcpy(dst, kernelbuf, n);
            kernelbuf += n;
        }

        priv->tag = sector;
        priv->dirty = true;

        mutex_unlock(&priv->mutex);

        *pos += n;
        remaining -= n;
        sector += priv->chunk_sectors;
        offset = 0;
    } while (remaining > 0);

    return count;

fail:
    mutex_unlock(&priv->mutex);
    return res;
}

static ssize_t ps3flash_user_read(struct file *file, char __user *buf,
                  size_t count, loff_t *pos)
{
    return ps3flash_read(buf, NULL, count, pos);
}

static ssize_t ps3flash_user_write(struct file *file, const char __user *buf,
                   size_t count, loff_t *pos)
{
    return ps3flash_write(buf, NULL, count, pos);
}

static ssize_t ps3flash_kernel_read(void *buf, size_t count, loff_t pos)
{
    return ps3flash_read(NULL, buf, count, &pos);
}

static ssize_t ps3flash_kernel_write(const void *buf, size_t count,
                     loff_t pos)
{
    ssize_t res;
    int wb;

    res = ps3flash_write(NULL, buf, count, &pos);
    if (res < 0)
        return res;

    /* Make kernel writes synchronous */
    wb = ps3flash_writeback(ps3flash_dev);
    if (wb)
        return wb;

    return res;
}

static int ps3flash_flush(struct file *file, fl_owner_t id)
{
    return ps3flash_writeback(ps3flash_dev);
}

static int ps3flash_fsync(struct file *file, loff_t start, loff_t end, int datasync)
{
    struct inode *inode = file->f_path.dentry->d_inode;
    int err;
    mutex_lock(&inode->i_mutex);
    err = ps3flash_writeback(ps3flash_dev);
    mutex_unlock(&inode->i_mutex);
    return err;
}

static irqreturn_t ps3flash_interrupt(int irq, void *data)
{
    struct ps3_storage_device *dev = data;
    int res;
    u64 tag, status;

    res = lv1_storage_get_async_status(dev->sbd.dev_id, &tag, &status);

    if (tag != dev->tag)
        dev_err(&dev->sbd.core,
            "%s:%u: tag mismatch, got %llx, expected %llx\n",
            __func__, __LINE__, tag, dev->tag);

    if (res) {
        dev_err(&dev->sbd.core, "%s:%u: res=%d status=0x%llx\n",
            __func__, __LINE__, res, status);
    } else {
        dev->lv1_status = status;
        complete(&dev->done);
    }
    return IRQ_HANDLED;
}

static const struct file_operations ps3flash_fops = {
    .owner  = THIS_MODULE,
    .llseek = ps3flash_llseek,
    .read   = ps3flash_user_read,
    .write  = ps3flash_user_write,
    .flush  = ps3flash_flush,
    .fsync  = ps3flash_fsync,
};

static const struct ps3_os_area_flash_ops ps3flash_kernel_ops = {
    .read   = ps3flash_kernel_read,
    .write  = ps3flash_kernel_write,
};

static struct miscdevice ps3flash_misc = {
    .minor  = MISC_DYNAMIC_MINOR,
    .name   = DEVICE_NAME,
    .fops   = &ps3flash_fops,
};

static int __devinit ps3flash_probe(struct ps3_system_bus_device *_dev)
{
    struct ps3_storage_device *dev = to_ps3_storage_device(&_dev->core);
    struct ps3flash_private *priv;
    int error;
    unsigned long tmp;

    tmp = dev->regions[dev->region_idx].start*dev->blk_size;
    if (tmp % FLASH_BLOCK_SIZE) {
        dev_err(&dev->sbd.core,
            "%s:%u region start %lu is not aligned\n", __func__,
            __LINE__, tmp);
        return -EINVAL;
    }
    tmp = dev->regions[dev->region_idx].size*dev->blk_size;
    if (tmp % FLASH_BLOCK_SIZE) {
        dev_err(&dev->sbd.core,
            "%s:%u region size %lu is not aligned\n", __func__,
            __LINE__, tmp);
        return -EINVAL;
    }

    /* use static buffer, kmalloc cannot allocate 256 KiB */
    if (!ps3flash_bounce_buffer.address)
        return -ENODEV;

    if (ps3flash_dev) {
        dev_err(&dev->sbd.core,
            "Only one FLASH device is supported\n");
        return -EBUSY;
    }

    ps3flash_dev = dev;

    priv = kzalloc(sizeof(*priv), GFP_KERNEL);
    if (!priv) {
        error = -ENOMEM;
        goto fail;
    }

    ps3_system_bus_set_drvdata(&dev->sbd, priv);
    mutex_init(&priv->mutex);
    priv->tag = -1;

    dev->bounce_size = ps3flash_bounce_buffer.size;
    dev->bounce_buf = ps3flash_bounce_buffer.address;
    priv->chunk_sectors = dev->bounce_size / dev->blk_size;

    error = ps3stor_setup(dev, ps3flash_interrupt);
    if (error)
        goto fail_free_priv;

    ps3flash_misc.parent = &dev->sbd.core;
    error = misc_register(&ps3flash_misc);
    if (error) {
        dev_err(&dev->sbd.core, "%s:%u: misc_register failed %d\n",
            __func__, __LINE__, error);
        goto fail_teardown;
    }

    dev_info(&dev->sbd.core, "%s:%u: registered misc device %d\n",
         __func__, __LINE__, ps3flash_misc.minor);

    ps3_os_area_flash_register(&ps3flash_kernel_ops);
    return 0;

fail_teardown:
    ps3stor_teardown(dev);
fail_free_priv:
    kfree(priv);
    ps3_system_bus_set_drvdata(&dev->sbd, NULL);
fail:
    ps3flash_dev = NULL;
    return error;
}

static int ps3flash_remove(struct ps3_system_bus_device *_dev)
{
    struct ps3_storage_device *dev = to_ps3_storage_device(&_dev->core);

    ps3_os_area_flash_register(NULL);
    misc_deregister(&ps3flash_misc);
    ps3stor_teardown(dev);
    kfree(ps3_system_bus_get_drvdata(&dev->sbd));
    ps3_system_bus_set_drvdata(&dev->sbd, NULL);
    ps3flash_dev = NULL;
    return 0;
}


static struct ps3_system_bus_driver ps3flash = {
    .match_id   = PS3_MATCH_ID_STOR_FLASH,
    .core.name  = DEVICE_NAME,
    .core.owner = THIS_MODULE,
    .probe      = ps3flash_probe,
    .remove     = ps3flash_remove,
    .shutdown   = ps3flash_remove,
};


static int __init ps3flash_init(void)
{
    return ps3_system_bus_driver_register(&ps3flash);
}

static void __exit ps3flash_exit(void)
{
    ps3_system_bus_driver_unregister(&ps3flash);
}

module_init(ps3flash_init);
module_exit(ps3flash_exit);

MODULE_LICENSE("GPL");
MODULE_DESCRIPTION("PS3 FLASH ROM Storage Driver");
MODULE_AUTHOR("Sony Corporation");
MODULE_ALIAS(PS3_MODULE_ALIAS_STOR_FLASH);