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linux/drivers/char/nwflash.c
Linus Torvalds 96d4f267e4 Remove 'type' argument from access_ok() function 
Nobody has actually used the type (VERIFY_READ vs VERIFY_WRITE) argument
of the user address range verification function since we got rid of the
old racy i386-only code to walk page tables by hand.

It existed because the original 80386 would not honor the write protect
bit when in kernel mode, so you had to do COW by hand before doing any
user access.  But we haven't supported that in a long time, and these
days the 'type' argument is a purely historical artifact.

A discussion about extending 'user_access_begin()' to do the range
checking resulted this patch, because there is no way we're going to
move the old VERIFY_xyz interface to that model.  And it's best done at
the end of the merge window when I've done most of my merges, so let's
just get this done once and for all.

This patch was mostly done with a sed-script, with manual fix-ups for
the cases that weren't of the trivial 'access_ok(VERIFY_xyz' form.

There were a couple of notable cases:

 - csky still had the old "verify_area()" name as an alias.

 - the iter_iov code had magical hardcoded knowledge of the actual
   values of VERIFY_{READ,WRITE} (not that they mattered, since nothing
   really used it)

 - microblaze used the type argument for a debug printout

but other than those oddities this should be a total no-op patch.

I tried to fix up all architectures, did fairly extensive grepping for
access_ok() uses, and the changes are trivial, but I may have missed
something.  Any missed conversion should be trivially fixable, though.

Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2019-01-03 18:57:57 -08:00

626 lines
13 KiB
C
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/*
* Flash memory interface rev.5 driver for the Intel
* Flash chips used on the NetWinder.
*
* 20/08/2000 RMK use __ioremap to map flash into virtual memory
* make a few more places use "volatile"
* 22/05/2001 RMK - Lock read against write
* - merge printk level changes (with mods) from Alan Cox.
* - use *ppos as the file position, not file->f_pos.
* - fix check for out of range pos and r/w size
*
* Please note that we are tampering with the only flash chip in the
* machine, which contains the bootup code. We therefore have the
* power to convert these machines into doorstops...
*/
#include <linux/module.h>
#include <linux/types.h>
#include <linux/fs.h>
#include <linux/errno.h>
#include <linux/mm.h>
#include <linux/delay.h>
#include <linux/proc_fs.h>
#include <linux/miscdevice.h>
#include <linux/spinlock.h>
#include <linux/rwsem.h>
#include <linux/init.h>
#include <linux/mutex.h>
#include <linux/jiffies.h>
#include <asm/hardware/dec21285.h>
#include <asm/io.h>
#include <asm/mach-types.h>
#include <linux/uaccess.h>
/*****************************************************************************/
#include <asm/nwflash.h>
#define NWFLASH_VERSION "6.4"
static DEFINE_MUTEX(flash_mutex);
static void kick_open(void);
static int get_flash_id(void);
static int erase_block(int nBlock);
static int write_block(unsigned long p, const char __user *buf, int count);
#define KFLASH_SIZE 1024*1024 //1 Meg
#define KFLASH_SIZE4 4*1024*1024 //4 Meg
#define KFLASH_ID 0x89A6 //Intel flash
#define KFLASH_ID4 0xB0D4 //Intel flash 4Meg
static bool flashdebug; //if set - we will display progress msgs
static int gbWriteEnable;
static int gbWriteBase64Enable;
static volatile unsigned char *FLASH_BASE;
static int gbFlashSize = KFLASH_SIZE;
static DEFINE_MUTEX(nwflash_mutex);
static int get_flash_id(void)
{
volatile unsigned int c1, c2;
/*
* try to get flash chip ID
*/
kick_open();
c2 = inb(0x80);
*(volatile unsigned char *) (FLASH_BASE + 0x8000) = 0x90;
udelay(15);
c1 = *(volatile unsigned char *) FLASH_BASE;
c2 = inb(0x80);
/*
* on 4 Meg flash the second byte is actually at offset 2...
*/
if (c1 == 0xB0)
c2 = *(volatile unsigned char *) (FLASH_BASE + 2);
else
c2 = *(volatile unsigned char *) (FLASH_BASE + 1);
c2 += (c1 << 8);
/*
* set it back to read mode
*/
*(volatile unsigned char *) (FLASH_BASE + 0x8000) = 0xFF;
if (c2 == KFLASH_ID4)
gbFlashSize = KFLASH_SIZE4;
return c2;
}
static long flash_ioctl(struct file *filep, unsigned int cmd, unsigned long arg)
{
mutex_lock(&flash_mutex);
switch (cmd) {
case CMD_WRITE_DISABLE:
gbWriteBase64Enable = 0;
gbWriteEnable = 0;
break;
case CMD_WRITE_ENABLE:
gbWriteEnable = 1;
break;
case CMD_WRITE_BASE64K_ENABLE:
gbWriteBase64Enable = 1;
break;
default:
gbWriteBase64Enable = 0;
gbWriteEnable = 0;
mutex_unlock(&flash_mutex);
return -EINVAL;
}
mutex_unlock(&flash_mutex);
return 0;
}
static ssize_t flash_read(struct file *file, char __user *buf, size_t size,
loff_t *ppos)
{
ssize_t ret;
if (flashdebug)
printk(KERN_DEBUG "flash_read: flash_read: offset=0x%llx, "
"buffer=%p, count=0x%zx.\n", *ppos, buf, size);
/*
* We now lock against reads and writes. --rmk
*/
if (mutex_lock_interruptible(&nwflash_mutex))
return -ERESTARTSYS;
ret = simple_read_from_buffer(buf, size, ppos, (void *)FLASH_BASE, gbFlashSize);
mutex_unlock(&nwflash_mutex);
return ret;
}
static ssize_t flash_write(struct file *file, const char __user *buf,
size_t size, loff_t * ppos)
{
unsigned long p = *ppos;
unsigned int count = size;
int written;
int nBlock, temp, rc;
int i, j;
if (flashdebug)
printk("flash_write: offset=0x%lX, buffer=0x%p, count=0x%X.\n",
p, buf, count);
if (!gbWriteEnable)
return -EINVAL;
if (p < 64 * 1024 && (!gbWriteBase64Enable))
return -EINVAL;
/*
* check for out of range pos or count
*/
if (p >= gbFlashSize)
return count ? -ENXIO : 0;
if (count > gbFlashSize - p)
count = gbFlashSize - p;
if (!access_ok(buf, count))
return -EFAULT;
/*
* We now lock against reads and writes. --rmk
*/
if (mutex_lock_interruptible(&nwflash_mutex))
return -ERESTARTSYS;
written = 0;
nBlock = (int) p >> 16; //block # of 64K bytes
/*
* # of 64K blocks to erase and write
*/
temp = ((int) (p + count) >> 16) - nBlock + 1;
/*
* write ends at exactly 64k boundary?
*/
if (((int) (p + count) & 0xFFFF) == 0)
temp -= 1;
if (flashdebug)
printk(KERN_DEBUG "flash_write: writing %d block(s) "
"starting at %d.\n", temp, nBlock);
for (; temp; temp--, nBlock++) {
if (flashdebug)
printk(KERN_DEBUG "flash_write: erasing block %d.\n", nBlock);
/*
* first we have to erase the block(s), where we will write...
*/
i = 0;
j = 0;
RetryBlock:
do {
rc = erase_block(nBlock);
i++;
} while (rc && i < 10);
if (rc) {
printk(KERN_ERR "flash_write: erase error %x\n", rc);
break;
}
if (flashdebug)
printk(KERN_DEBUG "flash_write: writing offset %lX, "
"from buf %p, bytes left %X.\n", p, buf,
count - written);
/*
* write_block will limit write to space left in this block
*/
rc = write_block(p, buf, count - written);
j++;
/*
* if somehow write verify failed? Can't happen??
*/
if (!rc) {
/*
* retry up to 10 times
*/
if (j < 10)
goto RetryBlock;
else
/*
* else quit with error...
*/
rc = -1;
}
if (rc < 0) {
printk(KERN_ERR "flash_write: write error %X\n", rc);
break;
}
p += rc;
buf += rc;
written += rc;
*ppos += rc;
if (flashdebug)
printk(KERN_DEBUG "flash_write: written 0x%X bytes OK.\n", written);
}
mutex_unlock(&nwflash_mutex);
return written;
}
/*
* The memory devices use the full 32/64 bits of the offset, and so we cannot
* check against negative addresses: they are ok. The return value is weird,
* though, in that case (0).
*
* also note that seeking relative to the "end of file" isn't supported:
* it has no meaning, so it returns -EINVAL.
*/
static loff_t flash_llseek(struct file *file, loff_t offset, int orig)
{
loff_t ret;
mutex_lock(&flash_mutex);
if (flashdebug)
printk(KERN_DEBUG "flash_llseek: offset=0x%X, orig=0x%X.\n",
(unsigned int) offset, orig);
ret = no_seek_end_llseek_size(file, offset, orig, gbFlashSize);
mutex_unlock(&flash_mutex);
return ret;
}
/*
* assume that main Write routine did the parameter checking...
* so just go ahead and erase, what requested!
*/
static int erase_block(int nBlock)
{
volatile unsigned int c1;
volatile unsigned char *pWritePtr;
unsigned long timeout;
int temp, temp1;
/*
* reset footbridge to the correct offset 0 (...0..3)
*/
*CSR_ROMWRITEREG = 0;
/*
* dummy ROM read
*/
c1 = *(volatile unsigned char *) (FLASH_BASE + 0x8000);
kick_open();
/*
* reset status if old errors
*/
*(volatile unsigned char *) (FLASH_BASE + 0x8000) = 0x50;
/*
* erase a block...
* aim at the middle of a current block...
*/
pWritePtr = (unsigned char *) ((unsigned int) (FLASH_BASE + 0x8000 + (nBlock << 16)));
/*
* dummy read
*/
c1 = *pWritePtr;
kick_open();
/*
* erase
*/
*(volatile unsigned char *) pWritePtr = 0x20;
/*
* confirm
*/
*(volatile unsigned char *) pWritePtr = 0xD0;
/*
* wait 10 ms
*/
msleep(10);
/*
* wait while erasing in process (up to 10 sec)
*/
timeout = jiffies + 10 * HZ;
c1 = 0;
while (!(c1 & 0x80) && time_before(jiffies, timeout)) {
msleep(10);
/*
* read any address
*/
c1 = *(volatile unsigned char *) (pWritePtr);
// printk("Flash_erase: status=%X.\n",c1);
}
/*
* set flash for normal read access
*/
kick_open();
// *(volatile unsigned char*)(FLASH_BASE+0x8000) = 0xFF;
*(volatile unsigned char *) pWritePtr = 0xFF; //back to normal operation
/*
* check if erase errors were reported
*/
if (c1 & 0x20) {
printk(KERN_ERR "flash_erase: err at %p\n", pWritePtr);
/*
* reset error
*/
*(volatile unsigned char *) (FLASH_BASE + 0x8000) = 0x50;
return -2;
}
/*
* just to make sure - verify if erased OK...
*/
msleep(10);
pWritePtr = (unsigned char *) ((unsigned int) (FLASH_BASE + (nBlock << 16)));
for (temp = 0; temp < 16 * 1024; temp++, pWritePtr += 4) {
if ((temp1 = *(volatile unsigned int *) pWritePtr) != 0xFFFFFFFF) {
printk(KERN_ERR "flash_erase: verify err at %p = %X\n",
pWritePtr, temp1);
return -1;
}
}
return 0;
}
/*
* write_block will limit number of bytes written to the space in this block
*/
static int write_block(unsigned long p, const char __user *buf, int count)
{
volatile unsigned int c1;
volatile unsigned int c2;
unsigned char *pWritePtr;
unsigned int uAddress;
unsigned int offset;
unsigned long timeout;
unsigned long timeout1;
pWritePtr = (unsigned char *) ((unsigned int) (FLASH_BASE + p));
/*
* check if write will end in this block....
*/
offset = p & 0xFFFF;
if (offset + count > 0x10000)
count = 0x10000 - offset;
/*
* wait up to 30 sec for this block
*/
timeout = jiffies + 30 * HZ;
for (offset = 0; offset < count; offset++, pWritePtr++) {
uAddress = (unsigned int) pWritePtr;
uAddress &= 0xFFFFFFFC;
if (__get_user(c2, buf + offset))
return -EFAULT;
WriteRetry:
/*
* dummy read
*/
c1 = *(volatile unsigned char *) (FLASH_BASE + 0x8000);
/*
* kick open the write gate
*/
kick_open();
/*
* program footbridge to the correct offset...0..3
*/
*CSR_ROMWRITEREG = (unsigned int) pWritePtr & 3;
/*
* write cmd
*/
*(volatile unsigned char *) (uAddress) = 0x40;
/*
* data to write
*/
*(volatile unsigned char *) (uAddress) = c2;
/*
* get status
*/
*(volatile unsigned char *) (FLASH_BASE + 0x10000) = 0x70;
c1 = 0;
/*
* wait up to 1 sec for this byte
*/
timeout1 = jiffies + 1 * HZ;
/*
* while not ready...
*/
while (!(c1 & 0x80) && time_before(jiffies, timeout1))
c1 = *(volatile unsigned char *) (FLASH_BASE + 0x8000);
/*
* if timeout getting status
*/
if (time_after_eq(jiffies, timeout1)) {
kick_open();
/*
* reset err
*/
*(volatile unsigned char *) (FLASH_BASE + 0x8000) = 0x50;
goto WriteRetry;
}
/*
* switch on read access, as a default flash operation mode
*/
kick_open();
/*
* read access
*/
*(volatile unsigned char *) (FLASH_BASE + 0x8000) = 0xFF;
/*
* if hardware reports an error writing, and not timeout -
* reset the chip and retry
*/
if (c1 & 0x10) {
kick_open();
/*
* reset err
*/
*(volatile unsigned char *) (FLASH_BASE + 0x8000) = 0x50;
/*
* before timeout?
*/
if (time_before(jiffies, timeout)) {
if (flashdebug)
printk(KERN_DEBUG "write_block: Retrying write at 0x%X)n",
pWritePtr - FLASH_BASE);
/*
* wait couple ms
*/
msleep(10);
goto WriteRetry;
} else {
printk(KERN_ERR "write_block: timeout at 0x%X\n",
pWritePtr - FLASH_BASE);
/*
* return error -2
*/
return -2;
}
}
}
msleep(10);
pWritePtr = (unsigned char *) ((unsigned int) (FLASH_BASE + p));
for (offset = 0; offset < count; offset++) {
char c, c1;
if (__get_user(c, buf))
return -EFAULT;
buf++;
if ((c1 = *pWritePtr++) != c) {
printk(KERN_ERR "write_block: verify error at 0x%X (%02X!=%02X)\n",
pWritePtr - FLASH_BASE, c1, c);
return 0;
}
}
return count;
}
static void kick_open(void)
{
unsigned long flags;
/*
* we want to write a bit pattern XXX1 to Xilinx to enable
* the write gate, which will be open for about the next 2ms.
*/
raw_spin_lock_irqsave(&nw_gpio_lock, flags);
nw_cpld_modify(CPLD_FLASH_WR_ENABLE, CPLD_FLASH_WR_ENABLE);
raw_spin_unlock_irqrestore(&nw_gpio_lock, flags);
/*
* let the ISA bus to catch on...
*/
udelay(25);
}
static const struct file_operations flash_fops =
{
.owner = THIS_MODULE,
.llseek = flash_llseek,
.read = flash_read,
.write = flash_write,
.unlocked_ioctl = flash_ioctl,
};
static struct miscdevice flash_miscdev =
{
FLASH_MINOR,
"nwflash",
&flash_fops
};
static int __init nwflash_init(void)
{
int ret = -ENODEV;
if (machine_is_netwinder()) {
int id;
FLASH_BASE = ioremap(DC21285_FLASH, KFLASH_SIZE4);
if (!FLASH_BASE)
goto out;
id = get_flash_id();
if ((id != KFLASH_ID) && (id != KFLASH_ID4)) {
ret = -ENXIO;
iounmap((void *)FLASH_BASE);
printk("Flash: incorrect ID 0x%04X.\n", id);
goto out;
}
printk("Flash ROM driver v.%s, flash device ID 0x%04X, size %d Mb.\n",
NWFLASH_VERSION, id, gbFlashSize / (1024 * 1024));
ret = misc_register(&flash_miscdev);
if (ret < 0) {
iounmap((void *)FLASH_BASE);
}
}
out:
return ret;
}
static void __exit nwflash_exit(void)
{
misc_deregister(&flash_miscdev);
iounmap((void *)FLASH_BASE);
}
MODULE_LICENSE("GPL");
module_param(flashdebug, bool, 0644);
module_init(nwflash_init);
module_exit(nwflash_exit);
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