drivers: Push down BKL into various drivers
[safe/jmp/linux-2.6] / drivers / char / ps3flash.c
index afbe456..606048b 100644 (file)
@@ -20,6 +20,7 @@
 
 #include <linux/fs.h>
 #include <linux/miscdevice.h>
+#include <linux/slab.h>
 #include <linux/uaccess.h>
 
 #include <asm/lv1call.h>
 
 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 start_sector, int write)
 {
-       u64 res = ps3stor_read_write_sectors(dev, lpar, start_sector, sectors,
+       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 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;
 
-       lpar = dev->bounce_lpar + sector_offset * dev->blk_size;
-       return ps3flash_read_write_sectors(dev, lpar, start_sector, sectors,
-                                          0);
+       res = ps3flash_read_write_sectors(dev, priv->tag, 1);
+       if (res)
+               return res;
+
+       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 = 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);
+       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)
@@ -104,18 +121,19 @@ out:
        return res;
 }
 
-static ssize_t ps3flash_read(struct file *file, char __user *buf, size_t count,
-                            loff_t *pos)
+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 = dev->sbd.core.driver_data;
-       u64 size, start_sector, end_sector, offset;
-       ssize_t sectors_read;
+       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 user 0x%p\n",
-               __func__, __LINE__, count, *pos, buf);
+               "%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)
@@ -128,61 +146,63 @@ static ssize_t ps3flash_read(struct file *file, char __user *buf, size_t count,
                count = size - *pos;
        }
 
-       start_sector = *pos / dev->blk_size;
-       offset = *pos % dev->blk_size;
-       end_sector = DIV_ROUND_UP(*pos + count, dev->blk_size);
+       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);
 
-               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, sector);
+               if (res)
                        goto fail;
-               }
 
-               n = min_t(u64, 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;
+                       "%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;
-               buf += n;
                remaining -= n;
-               start_sector += sectors_read;
+               sector += priv->chunk_sectors;
                offset = 0;
        } while (remaining > 0);
 
        return count;
 
 fail:
-       return sectors_read;
+       mutex_unlock(&priv->mutex);
+       return res;
 }
 
-static ssize_t ps3flash_write(struct file *file, const char __user *buf,
-                             size_t count, loff_t *pos)
+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 = 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;
+       struct ps3flash_private *priv = ps3_system_bus_get_drvdata(&dev->sbd);
+       u64 size, sector, offset;
+       int res = 0;
        size_t remaining, n;
-       unsigned int sec_off;
+       void *dst;
 
        dev_dbg(&dev->sbd.core,
-               "%s:%u: Writing %zu bytes at position %lld from user 0x%p\n",
-               __func__, __LINE__, count, *pos, buf);
+               "%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)
@@ -195,89 +215,46 @@ static ssize_t ps3flash_write(struct file *file, const char __user *buf,
                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);
+               dst = dev->bounce_buf + 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)
+               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;
-               } 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;
                        }
+                       userbuf += n;
                }
-
-               n = min_t(u64, 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;
+               if (kernelbuf) {
+                       memcpy(dst, kernelbuf, n);
+                       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;
-               buf += n;
                remaining -= n;
-               start_write_sector += chunk_sectors;
-               head = 0;
+               sector += priv->chunk_sectors;
                offset = 0;
        } while (remaining > 0);
 
@@ -288,6 +265,51 @@ fail:
        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, struct dentry *dentry,
+                         int datasync)
+{
+       return ps3flash_writeback(ps3flash_dev);
+}
 
 static irqreturn_t ps3flash_interrupt(int irq, void *data)
 {
@@ -312,12 +334,18 @@ static irqreturn_t ps3flash_interrupt(int irq, void *data)
        return IRQ_HANDLED;
 }
 
-
 static const struct file_operations ps3flash_fops = {
        .owner  = THIS_MODULE,
        .llseek = ps3flash_llseek,
-       .read   = ps3flash_read,
-       .write  = ps3flash_write,
+       .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 = {
@@ -366,11 +394,13 @@ static int __devinit ps3flash_probe(struct ps3_system_bus_device *_dev)
                goto fail;
        }
 
-       dev->sbd.core.driver_data = priv;
+       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)
@@ -386,13 +416,15 @@ static int __devinit ps3flash_probe(struct ps3_system_bus_device *_dev)
 
        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);
-       dev->sbd.core.driver_data = NULL;
+       ps3_system_bus_set_drvdata(&dev->sbd, NULL);
 fail:
        ps3flash_dev = NULL;
        return error;
@@ -402,10 +434,11 @@ 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(dev->sbd.core.driver_data);
-       dev->sbd.core.driver_data = NULL;
+       kfree(ps3_system_bus_get_drvdata(&dev->sbd));
+       ps3_system_bus_set_drvdata(&dev->sbd, NULL);
        ps3flash_dev = NULL;
        return 0;
 }