/*
* Return -1 if there is some form of error (couldn't find ring
* buffer, or buffer is of inappropriate size), 1 if there is no
* error, but there is no available buffer, 0 if found_buff and
* found_len are set to the buffer's values.
*
* See cos_types.h for a description of the structure of the buffer.
*/
int rb_retrieve_buff(struct thread *brand, int desired_len,
void **found_buf, int *found_len)
{
ring_buff_t *rb;
int position;
void *addr;
vaddr_t kaddr;
unsigned short int status, len;
struct spd *bspd;
assert(brand);
rb = brand->k_rb;
if (!rb) {
return -1;
}
position = brand->rb_next;
addr = rb->packets[position].ptr;
len = rb->packets[position].len;
status = rb->packets[position].status;
if (RB_READY != status || NULL == addr) {
return 1;
}
if (len < desired_len) {
printk("ring_buff: length of user buffer not sufficient.\n");
return -1;
}
bspd = thd_get_thd_spd(brand);
kaddr = chal_pgtbl_vaddr2kaddr(bspd->spd_info.pg_tbl, (unsigned long)addr);
if (!kaddr || !user_struct_fits_on_page(kaddr, len)) {
rb->packets[position].status = RB_ERR;
brand->rb_next = (position+1) & (RB_SIZE-1);
printk("ring_buff: user buffer either not in memory, or not page_aligned.\n");
return -1;
}
assert(kaddr);
// printk("kaddr to copy to is %x from ptr %x\n", kaddr, addr);
*found_buf = (void*)kaddr;
*found_len = len;
rb->packets[position].status = RB_USED;
brand->rb_next = (position+1) & (RB_SIZE-1);
return 0;
}
unsigned int *
pgtbl_module_to_vaddr(unsigned long addr)
{
return (unsigned int *)chal_pgtbl_vaddr2kaddr((paddr_t)chal_va2pa(current->mm->pgd), addr);
}
