linux-stable/drivers/char/ps3flash.c
Uwe Kleine-König 6d247e4d26 powerpc/ps3: make system bus's remove and shutdown callbacks return void
The driver core ignores the return value of struct device_driver::remove
because there is only little that can be done. For the shutdown callback
it's ps3_system_bus_shutdown() which ignores the return value.

To simplify the quest to make struct device_driver::remove return void,
let struct ps3_system_bus_driver::remove return void, too. All users
already unconditionally return 0, this commit makes it obvious that
returning an error code is a bad idea and ensures future users behave
accordingly.

Signed-off-by: Uwe Kleine-König <u.kleine-koenig@pengutronix.de>
Reviewed-by: Geert Uytterhoeven <geert@linux-m68k.org>
Acked-by: Takashi Iwai <tiwai@suse.de>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Link: https://lore.kernel.org/r/20201126165950.2554997-2-u.kleine-koenig@pengutronix.de
2020-12-04 01:01:22 +11:00

445 lines
10 KiB
C

// SPDX-License-Identifier: GPL-2.0-only
/*
* PS3 FLASH ROM Storage Driver
*
* Copyright (C) 2007 Sony Computer Entertainment Inc.
* Copyright 2007 Sony Corp.
*/
#include <linux/fs.h>
#include <linux/miscdevice.h>
#include <linux/slab.h>
#include <linux/uaccess.h>
#include <linux/module.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 */
u64 chunk_sectors;
int tag; /* Start sector of buffer, -1 if invalid */
bool dirty;
};
static struct ps3_storage_device *ps3flash_dev;
static int ps3flash_read_write_sectors(struct ps3_storage_device *dev,
u64 start_sector, int write)
{
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 0;
}
static int ps3flash_writeback(struct ps3_storage_device *dev)
{
struct ps3flash_private *priv = ps3_system_bus_get_drvdata(&dev->sbd);
int res;
if (!priv->dirty || priv->tag < 0)
return 0;
res = ps3flash_read_write_sectors(dev, priv->tag, 1);
if (res)
return res;
priv->dirty = false;
return 0;
}
static int ps3flash_fetch(struct ps3_storage_device *dev, u64 start_sector)
{
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)
{
struct ps3_storage_device *dev = ps3flash_dev;
return generic_file_llseek_size(file, offset, origin, MAX_LFS_FILESIZE,
dev->regions[dev->region_idx].size*dev->blk_size);
}
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 = 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 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)
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;
}
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);
res = ps3flash_fetch(dev, sector);
if (res)
goto fail;
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)) {
res = -EFAULT;
goto fail;
}
userbuf += n;
}
if (kernelbuf) {
memcpy(kernelbuf, src, n);
kernelbuf += n;
}
mutex_unlock(&priv->mutex);
*pos += n;
remaining -= n;
sector += priv->chunk_sectors;
offset = 0;
} while (remaining > 0);
return count;
fail:
mutex_unlock(&priv->mutex);
return res;
}
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 = ps3_system_bus_get_drvdata(&dev->sbd);
u64 size, sector, offset;
int res = 0;
size_t remaining, n;
void *dst;
dev_dbg(&dev->sbd.core,
"%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)
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;
}
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);
dst = dev->bounce_buf + offset;
mutex_lock(&priv->mutex);
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;
}
userbuf += n;
}
if (kernelbuf) {
memcpy(dst, kernelbuf, n);
kernelbuf += n;
}
priv->tag = sector;
priv->dirty = true;
mutex_unlock(&priv->mutex);
*pos += n;
remaining -= n;
sector += priv->chunk_sectors;
offset = 0;
} while (remaining > 0);
return count;
fail:
mutex_unlock(&priv->mutex);
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, loff_t start, loff_t end, int datasync)
{
struct inode *inode = file_inode(file);
int err;
inode_lock(inode);
err = ps3flash_writeback(ps3flash_dev);
inode_unlock(inode);
return err;
}
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 %llx, expected %llx\n",
__func__, __LINE__, tag, dev->tag);
if (res) {
dev_err(&dev->sbd.core, "%s:%u: res=%d status=0x%llx\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_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 = {
.minor = MISC_DYNAMIC_MINOR,
.name = DEVICE_NAME,
.fops = &ps3flash_fops,
};
static int 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;
}
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)
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);
ps3_os_area_flash_register(&ps3flash_kernel_ops);
return 0;
fail_teardown:
ps3stor_teardown(dev);
fail_free_priv:
kfree(priv);
ps3_system_bus_set_drvdata(&dev->sbd, NULL);
fail:
ps3flash_dev = NULL;
return error;
}
static void 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(ps3_system_bus_get_drvdata(&dev->sbd));
ps3_system_bus_set_drvdata(&dev->sbd, NULL);
ps3flash_dev = NULL;
}
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);