/*
* This funcion reads the *physical* memory. The f_pos points directly to the
* memory location.
*/
static ssize_t read_mem(struct file * file, char __user * buf,
size_t count, loff_t *ppos)
{
unsigned long p = *ppos;
ssize_t read;
if (!valid_phys_addr_range(p, &count))
return -EFAULT;
read = 0;
#if defined(__sparc__) || (defined(__mc68000__) && defined(CONFIG_MMU))
/* we don't have page 0 mapped on sparc and m68k.. */
if (p < PAGE_SIZE) {
unsigned long sz = PAGE_SIZE-p;
if (sz > count)
sz = count;
if (sz > 0) {
if (clear_user(buf, sz))
return -EFAULT;
buf += sz;
p += sz;
count -= sz;
read += sz;
}
}
#endif
if (copy_to_user(buf, __va(p), count))
return -EFAULT;
read += count;
*ppos += read;
return read;
}
static ssize_t write_mem(struct file * file, const char __user * buf,
size_t count, loff_t *ppos)
{
unsigned long p = *ppos;
if (!valid_phys_addr_range(p, &count))
return -EFAULT;
return do_write_mem(__va(p), p, buf, count, ppos);
}
/*
* This funcion reads the *physical* memory. The f_pos points directly to the
* memory location.
*/
static ssize_t read_mem(struct file * file, char __user * buf,
size_t count, loff_t *ppos)
{
unsigned long p = *ppos;
ssize_t read, sz;
char *ptr;
if (!valid_phys_addr_range(p, &count))
return -EFAULT;
read = 0;
#ifdef __ARCH_HAS_NO_PAGE_ZERO_MAPPED
/* we don't have page 0 mapped on sparc and m68k.. */
if (p < PAGE_SIZE) {
sz = PAGE_SIZE - p;
if (sz > count)
sz = count;
if (sz > 0) {
if (clear_user(buf, sz))
return -EFAULT;
buf += sz;
p += sz;
count -= sz;
read += sz;
}
}
#endif
while (count > 0) {
/*
* Handle first page in case it's not aligned
*/
if (-p & (PAGE_SIZE - 1))
sz = -p & (PAGE_SIZE - 1);
else
sz = PAGE_SIZE;
sz = min_t(unsigned long, sz, count);
/*
* On ia64 if a page has been mapped somewhere as
* uncached, then it must also be accessed uncached
* by the kernel or data corruption may occur
*/
ptr = xlate_dev_mem_ptr(p);
if (copy_to_user(buf, ptr, sz))
return -EFAULT;
buf += sz;
p += sz;
count -= sz;
read += sz;
}
*ppos += read;
return read;
}
static int log_buf_open(struct inode *inode, struct file *filp)
{
void *base;
/* determine the ram area is valid or not. */
if (!valid_phys_addr_range(log_start, log_size)
|| !memblock_is_region_reserved(log_start, log_size)) {
pr_err("%s: check memory range failed!\n", __func__);
return -EINVAL;
}
base = ioremap(log_start, log_size);
filp->private_data = base;
if (!base) {
pr_err("%s: remap error!\n", __func__);
return -ENOMEM;
}
return 0;
}
static ssize_t write_mem(struct file * file, const char __user * buf,
size_t count, loff_t *ppos)
{
unsigned long p = *ppos;
ssize_t written, sz;
unsigned long copied;
void *ptr;
if (!valid_phys_addr_range(p, &count))
return -EFAULT;
written = 0;
#ifdef __ARCH_HAS_NO_PAGE_ZERO_MAPPED
/* we don't have page 0 mapped on sparc and m68k.. */
if (p < PAGE_SIZE) {
unsigned long sz = PAGE_SIZE - p;
if (sz > count)
sz = count;
/* Hmm. Do something? */
buf += sz;
p += sz;
count -= sz;
written += sz;
}
#endif
while (count > 0) {
/*
* Handle first page in case it's not aligned
*/
if (-p & (PAGE_SIZE - 1))
sz = -p & (PAGE_SIZE - 1);
else
sz = PAGE_SIZE;
sz = min_t(unsigned long, sz, count);
/*
* On ia64 if a page has been mapped somewhere as
* uncached, then it must also be accessed uncached
* by the kernel or data corruption may occur
*/
ptr = xlate_dev_mem_ptr(p);
copied = copy_from_user(ptr, buf, sz);
if (copied) {
ssize_t ret;
ret = written + (sz - copied);
if (ret)
return ret;
return -EFAULT;
}
buf += sz;
p += sz;
count -= sz;
written += sz;
}
*ppos += written;
return written;
}
