ps3: FLASH ROM Storage Driver

Add a FLASH ROM Storage Driver for the PS3:
  - Implemented as a misc character device driver
  - Uses a fixed 256 KiB buffer allocated from boot memory as the hypervisor
    requires the writing of aligned 256 KiB blocks

Cc: Geoff Levand <geoffrey.levand@am.sony.com>
Signed-off-by: Geert Uytterhoeven <Geert.Uytterhoeven@sonycom.com>
Cc: Jens Axboe <jens.axboe@oracle.com>
Cc: James Bottomley <James.Bottomley@steeleye.com>
Cc: Paul Mackerras <paulus@samba.org>
Cc: Benjamin Herrenschmidt <benh@kernel.crashing.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

1 files changed, 440 insertions, 0 deletions

diff --git a/drivers/char/ps3flash.c b/drivers/char/ps3flash.c
new file mode 100644
index 000000000000..79b6f461be75
--- /dev/null
+++ b/drivers/char/ps3flash.c
@@ -0,0 +1,440 @@
+/*
+ * 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/uaccess.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 */
+};
+
+static struct ps3_storage_device *ps3flash_dev;
+
+static ssize_t ps3flash_read_write_sectors(struct ps3_storage_device *dev,
+                                           u64 lpar, u64 start_sector,
+                                           u64 sectors, int write)
+{
+        u64 res = ps3stor_read_write_sectors(dev, lpar, start_sector, sectors,
+                                             write);
+        if (res) {
+                dev_err(&dev->sbd.core, "%s:%u: %s failed 0x%lx\n", __func__,
+                        __LINE__, write ? "write" : "read", res);
+                return -EIO;
+        }
+        return sectors;
+}
+
+static ssize_t ps3flash_read_sectors(struct ps3_storage_device *dev,
+                                     u64 start_sector, u64 sectors,
+                                     unsigned int sector_offset)
+{
+        u64 max_sectors, lpar;
+
+        max_sectors = dev->bounce_size / dev->blk_size;
+        if (sectors > max_sectors) {
+                dev_dbg(&dev->sbd.core, "%s:%u Limiting sectors to %lu\n",
+                        __func__, __LINE__, max_sectors);
+                sectors = max_sectors;
+        }
+
+        lpar = dev->bounce_lpar + sector_offset * dev->blk_size;
+        return ps3flash_read_write_sectors(dev, lpar, start_sector, sectors,
+                                           0);
+}
+
+static ssize_t ps3flash_write_chunk(struct ps3_storage_device *dev,
+                                    u64 start_sector)
+{
+       u64 sectors = dev->bounce_size / dev->blk_size;
+       return ps3flash_read_write_sectors(dev, dev->bounce_lpar, start_sector,
+                                          sectors, 1);
+}
+
+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 1:
+                offset += file->f_pos;
+                break;
+        case 2:
+                offset += dev->regions[dev->region_idx].size*dev->blk_size;
+                break;
+        }
+        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(struct file *file, char __user *buf, size_t count,
+                             loff_t *pos)
+{
+        struct ps3_storage_device *dev = ps3flash_dev;
+        struct ps3flash_private *priv = dev->sbd.core.driver_data;
+        u64 size, start_sector, end_sector, offset;
+        ssize_t sectors_read;
+        size_t remaining, n;
+
+        dev_dbg(&dev->sbd.core,
+                "%s:%u: Reading %zu bytes at position %lld to user 0x%p\n",
+                __func__, __LINE__, count, *pos, buf);
+
+        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;
+        }
+
+        start_sector = *pos / dev->blk_size;
+        offset = *pos % dev->blk_size;
+        end_sector = DIV_ROUND_UP(*pos + count, dev->blk_size);
+
+        remaining = count;
+        do {
+                mutex_lock(&priv->mutex);
+
+                sectors_read = ps3flash_read_sectors(dev, start_sector,
+                                                     end_sector-start_sector,
+                                                     0);
+                if (sectors_read < 0) {
+                        mutex_unlock(&priv->mutex);
+                        goto fail;
+                }
+
+                n = min(remaining, sectors_read*dev->blk_size-offset);
+                dev_dbg(&dev->sbd.core,
+                        "%s:%u: copy %lu bytes from 0x%p to user 0x%p\n",
+                        __func__, __LINE__, n, dev->bounce_buf+offset, buf);
+                if (copy_to_user(buf, dev->bounce_buf+offset, n)) {
+                        mutex_unlock(&priv->mutex);
+                        sectors_read = -EFAULT;
+                        goto fail;
+                }
+
+                mutex_unlock(&priv->mutex);
+
+                *pos += n;
+                buf += n;
+                remaining -= n;
+                start_sector += sectors_read;
+                offset = 0;
+        } while (remaining > 0);
+
+        return count;
+
+fail:
+        return sectors_read;
+}
+
+static ssize_t ps3flash_write(struct file *file, const char __user *buf,
+                              size_t count, loff_t *pos)
+{
+        struct ps3_storage_device *dev = ps3flash_dev;
+        struct ps3flash_private *priv = dev->sbd.core.driver_data;
+        u64 size, chunk_sectors, start_write_sector, end_write_sector,
+            end_read_sector, start_read_sector, head, tail, offset;
+        ssize_t res;
+        size_t remaining, n;
+        unsigned int sec_off;
+
+        dev_dbg(&dev->sbd.core,
+                "%s:%u: Writing %zu bytes at position %lld from user 0x%p\n",
+                __func__, __LINE__, count, *pos, buf);
+
+        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;
+        }
+
+        chunk_sectors = dev->bounce_size / dev->blk_size;
+
+        start_write_sector = *pos / dev->bounce_size * chunk_sectors;
+        offset = *pos % dev->bounce_size;
+        end_write_sector = DIV_ROUND_UP(*pos + count, dev->bounce_size) *
+                           chunk_sectors;
+
+        end_read_sector = DIV_ROUND_UP(*pos, dev->blk_size);
+        start_read_sector = (*pos + count) / dev->blk_size;
+
+        /*
+         * As we have to write in 256 KiB chunks, while we can read in blk_size
+         * (usually 512 bytes) chunks, we perform the following steps:
+         *   1. Read from start_write_sector to end_read_sector ("head")
+         *   2. Read from start_read_sector to end_write_sector ("tail")
+         *   3. Copy data to buffer
+         *   4. Write from start_write_sector to end_write_sector
+         * All of this is complicated by using only one 256 KiB bounce buffer.
+         */
+
+        head = end_read_sector - start_write_sector;
+        tail = end_write_sector - start_read_sector;
+
+        remaining = count;
+        do {
+                mutex_lock(&priv->mutex);
+
+                if (end_read_sector >= start_read_sector) {
+                        /* Merge head and tail */
+                        dev_dbg(&dev->sbd.core,
+                                "Merged head and tail: %lu sectors at %lu\n",
+                                chunk_sectors, start_write_sector);
+                        res = ps3flash_read_sectors(dev, start_write_sector,
+                                                    chunk_sectors, 0);
+                        if (res < 0)
+                                goto fail;
+                } else {
+                        if (head) {
+                                /* Read head */
+                                dev_dbg(&dev->sbd.core,
+                                        "head: %lu sectors at %lu\n", head,
+                                        start_write_sector);
+                                res = ps3flash_read_sectors(dev,
+                                                            start_write_sector,
+                                                            head, 0);
+                                if (res < 0)
+                                        goto fail;
+                        }
+                        if (start_read_sector <
+                            start_write_sector+chunk_sectors) {
+                                /* Read tail */
+                                dev_dbg(&dev->sbd.core,
+                                        "tail: %lu sectors at %lu\n", tail,
+                                        start_read_sector);
+                                sec_off = start_read_sector-start_write_sector;
+                                res = ps3flash_read_sectors(dev,
+                                                            start_read_sector,
+                                                            tail, sec_off);
+                                if (res < 0)
+                                        goto fail;
+                        }
+                }
+
+                n = min(remaining, dev->bounce_size-offset);
+                dev_dbg(&dev->sbd.core,
+                        "%s:%u: copy %lu bytes from user 0x%p to 0x%p\n",
+                        __func__, __LINE__, n, buf, dev->bounce_buf+offset);
+                if (copy_from_user(dev->bounce_buf+offset, buf, n)) {
+                        res = -EFAULT;
+                        goto fail;
+                }
+
+                res = ps3flash_write_chunk(dev, start_write_sector);
+                if (res < 0)
+                        goto fail;
+
+                mutex_unlock(&priv->mutex);
+
+                *pos += n;
+                buf += n;
+                remaining -= n;
+                start_write_sector += chunk_sectors;
+                head = 0;
+                offset = 0;
+        } while (remaining > 0);
+
+        return count;
+
+fail:
+        mutex_unlock(&priv->mutex);
+        return res;
+}
+
+
+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 %lx, expected %lx\n",
+                        __func__, __LINE__, tag, dev->tag);
+
+        if (res) {
+                dev_err(&dev->sbd.core, "%s:%u: res=%d status=0x%lx\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_read,
+        .write  = ps3flash_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;
+        }
+
+        dev->sbd.core.driver_data = priv;
+        mutex_init(&priv->mutex);
+
+        dev->bounce_size = ps3flash_bounce_buffer.size;
+        dev->bounce_buf = ps3flash_bounce_buffer.address;
+
+        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);
+        return 0;
+
+fail_teardown:
+        ps3stor_teardown(dev);
+fail_free_priv:
+        kfree(priv);
+        dev->sbd.core.driver_data = 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);
+
+        misc_deregister(&ps3flash_misc);
+        ps3stor_teardown(dev);
+        kfree(dev->sbd.core.driver_data);
+        dev->sbd.core.driver_data = 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);