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#include <apos/dmem.h>
static struct mem_region_root pre_ram = { 0 };
static struct mem_region_root post_ram = { 0 };
pm_t __pre_base = 0;
pm_t __pre_top = 0;
pm_t __post_base = 0;
pm_t __post_top = 0;
stat_t init_devmem(pm_t ram_base, pm_t ram_top)
{
pm_t mem_top = (pm_t)-1;
__pre_base = 0;
__pre_top = ram_base - 1;
__post_base = ram_top;
__post_top = mem_top;
size_t pre_pages = __pages(__pre_top);
size_t post_pages = __pages(__post_top) - __pages(__post_base);
init_region(&pre_ram, __pre_base, pre_pages);
init_region(&post_ram, __post_base, post_pages);
return OK;
}
stat_t dev_alloc_wrapper(struct vm_branch *b, pm_t *offset, vm_t vaddr,
vmflags_t flags, enum mm_order order)
{
map_vpage(b, *offset, vaddr, flags, order);
*offset += __o_size(order);
return OK;
}
stat_t dev_free_wrapper(struct vm_branch *b, pm_t *offset, vm_t vaddr,
vmflags_t flags, enum mm_order order)
{
UNUSED(offset);
UNUSED(flags);
pm_t paddr = 0;
enum mm_order v_order = 0;
stat_vpage(b, vaddr, &paddr, &v_order, 0);
if (order != v_order)
return REGION_TRY_AGAIN;
unmap_vpage(b, vaddr);
return OK;
}
vm_t alloc_devmem(struct tcb *t, pm_t dev_start, size_t bytes, vmflags_t flags)
{
vm_t region = 0;
if (dev_start < __pre_top)
region = alloc_region(&pre_ram, bytes, 0, flags);
if (dev_start > __post_base)
region = alloc_region(&post_ram, bytes, 0, flags);
if (!region)
return 0;
return map_fill_region(t->b_r, &dev_alloc_wrapper, dev_start, region,
bytes, flags);
}
stat_t free_devmem(struct tcb *t, vm_t dev_start)
{
pm_t dev_paddr = 0;
stat_vpage(t->b_r, dev_start, &dev_paddr, 0, 0);
if (dev_paddr >= __pre_top && dev_paddr <= __post_base)
return ERR_ADDR;
struct mem_region *m = 0;
if (dev_paddr < __pre_top)
m = find_used_region(&pre_ram, dev_paddr);
if (dev_paddr > __post_base)
m = find_used_region(&post_ram, dev_paddr);
if (!m)
return ERR_NF;
size_t region_size = __addr(m->end - m->start);
map_fill_region(t->b_r, &dev_free_wrapper, dev_paddr, dev_start,
region_size, 0);
if (dev_paddr < __pre_top)
free_region(&pre_ram, dev_paddr);
if (dev_paddr > __post_base)
free_region(&post_ram, dev_paddr);
return OK;
}
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