static errval_t do_single_map(struct pmap_arm *pmap, genvaddr_t vaddr, genvaddr_t vend,
struct capref frame, size_t offset, size_t pte_count,
vregion_flags_t flags)
{
// Get the page table
struct vnode *ptable;
errval_t err = get_ptable(pmap, vaddr, &ptable);
if (err_is_fail(err)) {
return err_push(err, LIB_ERR_PMAP_GET_PTABLE);
}
uintptr_t pmap_flags = vregion_flags_to_kpi_paging_flags(flags);
// XXX: reassess the following note -SG
// NOTE: strictly speaking a l2 entry only has 8 bits, but due to the way
// Barrelfish allocates l1 and l2 tables, we use 10 bits for the tracking
// index here and in the map syscall
uintptr_t index = ARM_USER_L2_OFFSET(vaddr);
// Create user level datastructure for the mapping
bool has_page = has_vnode(ptable, index, pte_count);
assert(!has_page);
struct vnode *page = slab_alloc(&pmap->slab);
assert(page);
page->is_vnode = false;
page->entry = index;
page->next = ptable->u.vnode.children;
ptable->u.vnode.children = page;
page->u.frame.cap = frame;
page->u.frame.pte_count = pte_count;
// Map entry into the page table
err = vnode_map(ptable->u.vnode.cap, frame, index,
pmap_flags, offset, pte_count);
if (err_is_fail(err)) {
return err_push(err, LIB_ERR_VNODE_MAP);
}
return SYS_ERR_OK;
}
// this should work for x86_64 and x86_32.
bool has_vnode(struct vnode *root, uint32_t entry, size_t len,
bool only_pages)
{
assert(root != NULL);
assert(root->is_vnode);
struct vnode *n;
uint32_t end_entry = entry + len;
// region we check [entry .. end_entry)
for (n = root->u.vnode.children; n; n = n->next) {
// n is page table, we need to check if it's anywhere inside the
// region to check [entry .. end_entry)
// this amounts to n->entry == entry for len = 1
if (n->is_vnode && n->entry >= entry && n->entry < end_entry) {
if (only_pages) {
return has_vnode(n, 0, PTABLE_SIZE, true);
}
#ifdef LIBBARRELFISH_DEBUG_PMAP
debug_printf("1: found page table inside our region\n");
#endif
return true;
} else if (n->is_vnode) {
// all other vnodes do not overlap with us, so go to next
assert(n->entry < entry || n->entry >= end_entry);
continue;
}
// this remains the same regardless of `only_pages`.
// n is frame [n->entry .. end)
// 3 cases:
// 1) entry < n->entry && end_entry >= end --> n is a strict subset of
// our region
// 2) entry inside n (entry >= n->entry && entry < end)
// 3) end_entry inside n (end_entry >= n->entry && end_entry < end)
uint32_t end = n->entry + n->u.frame.pte_count;
if (entry < n->entry && end_entry >= end) {
#ifdef LIBBARRELFISH_DEBUG_PMAP
debug_printf("2: found a strict subset of our region: (%"
PRIu32"--%"PRIu32") < (%"PRIu32"--%"PRIu32")\n",
n->entry, end, entry, end_entry);
#endif
return true;
}
if (entry >= n->entry && entry < end) {
#ifdef LIBBARRELFISH_DEBUG_PMAP
debug_printf("3: found a region starting inside our region: (%"
PRIu32"--%"PRIu32") <> (%"PRIu32"--%"PRIu32")\n",
n->entry, end, entry, end_entry);
#endif
return true;
}
if (end_entry > n->entry && end_entry < end) {
#ifdef LIBBARRELFISH_DEBUG_PMAP
debug_printf("4: found a region ending inside our region: (%"
PRIu32"--%"PRIu32") <> (%"PRIu32"--%"PRIu32")\n",
n->entry, end, entry, end_entry);
#endif
return true;
}
}
return false;
}