1 files changed, 104 insertions, 105 deletions

diff --git a/drivers/char/ps3flash.c b/drivers/char/ps3flash.c
index f7f21f47ea02..d884d31491d2 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)