int add_memarea_element(size_t start_address, int required_pages){
//Return -1 on error 0 on success
int posizione;
posizione = mem_info->next_free;
if(posizione>0 && posizione<510){
#ifdef DEBUG
printf("Posizione <510\n");
#endif
mem_info->pages_info[posizione].inizio = (void*)start_address;
mem_info->pages_info[posizione].num_pagine = required_pages;
mem_info->next_free++;
return 0;
}
else {
mem_info->next = request_pages(1, NOT_ADD_LIST);
mem_info = (mem_area_pointer) mem_info->next;
if(mem_info->next!=NULL){
mem_info = (mem_area_pointer)mem_info->next;
#ifdef DEBUG
printf("Posizione >510\n");
#endif
mem_info->pages_info[0].inizio = (void*)start_address;
mem_info->pages_info[0].num_pagine = required_pages;
mem_info->next_free = 1;
}
else return -1;
return 0;
}
return -1;
}
static struct page *
alloc_new_pte_page(struct pte_cache_list *clist)
{
struct page *page;
unsigned long pte_free_base = 0;
if (!clist->pte_free_size) {
/*
* alloc new page for pte pgt
*/
page = request_pages(1, GFP_PGT);
if (!page)
return NULL;
add_page_to_list_tail(page, &clist->pte_list);
clist->pte_alloc_size += PAGE_SIZE;
} else {
/*
* fetch a new page from the pte_list
*/
clist->pte_current_page =
list_next(clist->pte_current_page);
page = list_to_page(clist->pte_current_page);
clist->pte_free_size -= PAGE_SIZE;
}
pte_free_base = page_to_va(page);
memset((char *)pte_free_base, 0, PAGE_SIZE);
return page;
}
/*Da spostare appena termintao il gestore della memoria*/
void *fis_malloc(const size_t size){
return request_pages(size % 4096 ? size / 4096 + 1 : size / 4096, ADD_LIST);
}
int init_task_page_table(struct task_page_table *table)
{
unsigned long base = 0;
struct page *page;
struct pgt_temp_buffer *tb = &table->pgt_temp_buffer;
if (!table)
return -EINVAL;
/*
* if the page table has been alloced
* we reinit the pde and pte page table
*/
if (!table->pde_base) {
memset((char *)table, 0,
sizeof(struct task_page_table));
page = alloc_new_pde();
if (!page) {
kernel_error("No memory for task PDE\n");
return -ENOMEM;
}
table->pde_base = page_to_va(page);
table->pde_base_pa = page_to_pa(page);
/*
* init temp buffer
*/
tb->tbuf_pte_page = request_pages(1, GFP_PGT);
if (!tb->tbuf_pte_page) {
release_pde(base);
return -ENOMEM;
}
tb->tbuf_pte_base =
page_to_va(tb->tbuf_pte_page);
tb->tbuf_page_nr = PTES_PER_PDE;
}
/*
* if do memset op here, it will cause much time
* to be fix
*/
mmu_copy_kernel_pde(table->pde_base);
init_pte(table);
/*
* init temp_buffer member
*/
base = pgt_get_pde_entry_addr(table->pde_base,
KERNEL_TEMP_BUFFER_BASE);
mmu_create_pde_entry(base,
page_to_pa(tb->tbuf_pte_page),
KERNEL_TEMP_BUFFER_BASE);
table->mmap_current_base = PROCESS_USER_MMAP_BASE;
return 0;
}
