1 files changed, 104 insertions, 105 deletions

diff --git a/drivers/char/ps3flash.c b/drivers/char/ps3flash.c
index f7f21f4..d884d31 100644
--- a/drivers/char/ps3flash.c
+++ b/drivers/char/ps3flash.c
@@ -33,13 +33,16 @@
 
 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 ssize_t ps3flash_read_write_sectors(struct ps3_storage_device *dev,
-					   u64 lpar, u64 start_sector,
-					   u64 sectors, int write)
+static int 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);
@@ -48,33 +51,55 @@ static ssize_t ps3flash_read_write_sectors(struct ps3_storage_device *dev,
 			__LINE__, write ? "write" : "read", res);
 		return -EIO;
 	}
-	return sectors;
+	return 0;
 }
 
-static ssize_t ps3flash_read_sectors(struct ps3_storage_device *dev,
-				     u64 start_sector, u64 sectors,
-				     unsigned int sector_offset)
+static int ps3flash_writeback(struct ps3_storage_device *dev)
 {
-	u64 max_sectors, lpar;
+	struct ps3flash_private *priv = ps3_system_bus_get_drvdata(&dev->sbd);
+	int res;
 
-	max_sectors = dev->bounce_size / dev->blk_size;
-	if (sectors > max_sectors) {
-		dev_dbg(&dev->sbd.core, "%s:%u Limiting sectors to %llu\n",
-			__func__, __LINE__, max_sectors);
-		sectors = max_sectors;
-	}
+	if (!priv->dirty || priv->tag < 0)
+		return 0;
+
+	res = ps3flash_read_write_sectors(dev, dev->bounce_lpar, priv->tag,
+					  priv->chunk_sectors, 1);
+	if (res)
+		return res;
 
-	lpar = dev->bounce_lpar + sector_offset * dev->blk_size;
-	return ps3flash_read_write_sectors(dev, lpar, start_sector, sectors,
-					   0);
+	priv->dirty = false;
+	return 0;
 }
 
-static ssize_t ps3flash_write_chunk(struct ps3_storage_device *dev,
-				    u64 start_sector)
+static int ps3flash_fetch(struct ps3_storage_device *dev, u64 start_sector,
+			  u64 sectors)
 {
-       u64 sectors = dev->bounce_size / dev->blk_size;
-       return ps3flash_read_write_sectors(dev, dev->bounce_lpar, start_sector,
-					  sectors, 1);
+	struct ps3flash_private *priv = ps3_system_bus_get_drvdata(&dev->sbd);
+	unsigned int tag, offset;
+	u64 lpar;
+	int res;
+
+	offset = start_sector % priv->chunk_sectors;
+	tag = start_sector - offset;
+	if (tag == priv->tag)
+		return 0;
+
+	res = ps3flash_writeback(dev);
+	if (res)
+		return res;
+
+	priv->tag = -1;
+
+	lpar = dev->bounce_lpar + offset * dev->blk_size;
+	res = ps3flash_read_write_sectors(dev, lpar, start_sector, sectors, 0);
+	if (res)
+		return res;
+
+	/* We don't bother caching reads smaller than the chunk size */
+	if (sectors == priv->chunk_sectors)
+		priv->tag = tag;
+
+	return 0;
 }
 
 static loff_t ps3flash_llseek(struct file *file, loff_t offset, int origin)
@@ -109,8 +134,8 @@ static ssize_t ps3flash_read(char __user *userbuf, void *kernelbuf,
 {
 	struct ps3_storage_device *dev = ps3flash_dev;
 	struct ps3flash_private *priv = ps3_system_bus_get_drvdata(&dev->sbd);
-	u64 size, start_sector, end_sector, offset;
-	ssize_t sectors_read;
+	u64 size, start_sector, end_sector, offset, sectors;
+	int res;
 	size_t remaining, n;
 	const void *src;
 
@@ -130,30 +155,29 @@ static ssize_t ps3flash_read(char __user *userbuf, void *kernelbuf,
 	}
 
 	start_sector = *pos / dev->blk_size;
-	offset = *pos % dev->blk_size;
+	offset = *pos % dev->bounce_size;
 	end_sector = DIV_ROUND_UP(*pos + count, dev->blk_size);
 
 	remaining = count;
 	do {
+		sectors = min(end_sector - start_sector,
+			      priv->chunk_sectors -
+			      start_sector % priv->chunk_sectors);
+
 		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);
+		res = ps3flash_fetch(dev, start_sector, sectors);
+		if (res)
 			goto fail;
-		}
 
-		n = min_t(u64, remaining, sectors_read*dev->blk_size-offset);
-		src = dev->bounce_buf+offset;
+		n = min_t(u64, remaining, dev->bounce_size - offset);
+		src = dev->bounce_buf + offset;
 		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)) {
-				mutex_unlock(&priv->mutex);
-				sectors_read = -EFAULT;
+				res = -EFAULT;
 				goto fail;
 			}
 			userbuf += n;
@@ -167,14 +191,15 @@ static ssize_t ps3flash_read(char __user *userbuf, void *kernelbuf,
 
 		*pos += n;
 		remaining -= n;
-		start_sector += sectors_read;
+		start_sector += sectors;
 		offset = 0;
 	} while (remaining > 0);
 
 	return count;
 
 fail:
-	return sectors_read;
+	mutex_unlock(&priv->mutex);
+	return res;
 }
 
 static ssize_t ps3flash_write(const char __user *userbuf,
@@ -182,11 +207,9 @@ static ssize_t ps3flash_write(const char __user *userbuf,
 {
 	struct ps3_storage_device *dev = ps3flash_dev;
 	struct ps3flash_private *priv = ps3_system_bus_get_drvdata(&dev->sbd);
-	u64 size, chunk_sectors, start_write_sector, end_write_sector,
-	    end_read_sector, start_read_sector, head, tail, offset;
-	ssize_t res;
+	u64 size, sector, offset;
+	int res = 0;
 	size_t remaining, n;
-	unsigned int sec_off;
 	void *dst;
 
 	dev_dbg(&dev->sbd.core,
@@ -204,71 +227,23 @@ static ssize_t ps3flash_write(const char __user *userbuf,
 		count = size - *pos;
 	}
 
-	chunk_sectors = dev->bounce_size / dev->blk_size;
-
-	start_write_sector = *pos / dev->bounce_size * chunk_sectors;
+	sector = *pos / dev->bounce_size * priv->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 {
+		n = min_t(u64, remaining, dev->bounce_size - offset);
+
 		mutex_lock(&priv->mutex);
 
-		if (end_read_sector >= start_read_sector) {
-			/* Merge head and tail */
-			dev_dbg(&dev->sbd.core,
-				"Merged head and tail: %llu sectors at %llu\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: %llu sectors at %llu\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: %llu sectors at %llu\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;
-			}
-		}
+		if (n != dev->bounce_size)
+			res = ps3flash_fetch(dev, sector, priv->chunk_sectors);
+		else if (sector != priv->tag)
+			res = ps3flash_writeback(dev);
+		if (res)
+			goto fail;
 
-		n = min_t(u64, remaining, dev->bounce_size-offset);
-		dst = dev->bounce_buf+offset;
+		dst = dev->bounce_buf + offset;
 		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);
@@ -284,16 +259,14 @@ static ssize_t ps3flash_write(const char __user *userbuf,
 			kernelbuf += n;
 		}
 
-		res = ps3flash_write_chunk(dev, start_write_sector);
-		if (res < 0)
-			goto fail;
+		priv->tag = sector;
+		priv->dirty = true;
 
 		mutex_unlock(&priv->mutex);
 
 		*pos += n;
 		remaining -= n;
-		start_write_sector += chunk_sectors;
-		head = 0;
+		sector += priv->chunk_sectors;
 		offset = 0;
 	} while (remaining > 0);
 
@@ -324,9 +297,31 @@ static ssize_t ps3flash_kernel_read(void *buf, size_t count, loff_t pos)
 static ssize_t ps3flash_kernel_write(const void *buf, size_t count,
 				     loff_t pos)
 {
-	return ps3flash_write(NULL, buf, count, &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, struct dentry *dentry,
+			  int datasync)
+{
+	return ps3flash_writeback(ps3flash_dev);
+}
 
 static irqreturn_t ps3flash_interrupt(int irq, void *data)
 {
@@ -356,6 +351,8 @@ static const struct file_operations ps3flash_fops = {
 	.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 = {
@@ -411,9 +408,11 @@ static int __devinit ps3flash_probe(struct ps3_system_bus_device *_dev)
 
 	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)