Hi there...
I am trying to make a device driver (Kernel module) for a Virtex4 PowerPC, and i have a small problem...
The powerpc is byte addressable (little endian) but i my kernel functions as to return a int (32bit's) i already have a functional module but is not optimized
What i wold like to do is get a int without making the * and / (they take lot of CPU time). I think there is a way with some masks with FFFFFFFC using a AND. Is this possible i do not understand how it works...
does anyone have any ideas??
I am trying to make a device driver (Kernel module) for a Virtex4 PowerPC, and i have a small problem...
The powerpc is byte addressable (little endian) but i my kernel functions as to return a int (32bit's) i already have a functional module but is not optimized
Code:
ssize_t fpga_write(struct file *filp, int *buf, size_t count, loff_t *f_pos)
{
void *add;
int *kbuf;
kbuf = kmalloc(count, GFP_KERNEL);
int ret = copy_from_user(kbuf, buf, count);
int i;
for(i = *f_pos/4; i < count/4 + *f_pos/4; i++)
{
add = io_base + (i*4);
__raw_writel(kbuf[i - *f_pos], add);
}
kfree(kbuf);
return 1;
}What i wold like to do is get a int without making the * and / (they take lot of CPU time). I think there is a way with some masks with FFFFFFFC using a AND. Is this possible i do not understand how it works...
does anyone have any ideas??