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>

3 files changed, 457 insertions, 0 deletions

diff --git a/arch/powerpc/platforms/ps3/Kconfig b/arch/powerpc/platforms/ps3/Kconfig
index f6092916ebc..d4fc74f7bb1 100644
--- a/arch/powerpc/platforms/ps3/Kconfig
+++ b/arch/powerpc/platforms/ps3/Kconfig
@@ -123,4 +123,19 @@ config PS3_ROM
 	  In general, all users will say Y or M.
 	  Also make sure to say Y or M to "SCSI CDROM support" later.
 
+config PS3_FLASH
+	tristate "PS3 FLASH ROM Storage Driver"
+	depends on PPC_PS3
+	select PS3_STORAGE
+	help
+	  Include support for the PS3 FLASH ROM Storage.
+
+	  This support is required to access the PS3 FLASH ROM, which
+	  contains the boot loader and some boot options.
+	  In general, all users will say Y or M.
+
+	  As this driver needs a fixed buffer of 256 KiB of memory, it can
+	  be disabled on the kernel command line using "ps3flash=off", to
+	  not allocate this fixed buffer.
+
 endmenu
diff --git a/drivers/char/Makefile b/drivers/char/Makefile
index 4e6f387fd18..8fecaf4010b 100644
--- a/drivers/char/Makefile
+++ b/drivers/char/Makefile
@@ -107,6 +107,8 @@ obj-$(CONFIG_IPMI_HANDLER)	+= ipmi/
 obj-$(CONFIG_HANGCHECK_TIMER)	+= hangcheck-timer.o
 obj-$(CONFIG_TCG_TPM)		+= tpm/
 
+obj-$(CONFIG_PS3_FLASH)		+= ps3flash.o
+
 # Files generated that shall be removed upon make clean
 clean-files := consolemap_deftbl.c defkeymap.c
 
diff --git a/drivers/char/ps3flash.c b/drivers/char/ps3flash.c
new file mode 100644
index 00000000000..79b6f461be7
--- /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);