diff options
| -rw-r--r-- | exec.c | 28 |
1 files changed, 17 insertions, 11 deletions
@@ -193,19 +193,20 @@ static unsigned phys_sections_nb, phys_sections_nb_alloc; static uint16_t phys_section_unassigned; struct PhysPageEntry { - /* index into phys_sections (last level) or phys_map_nodes (others) */ - uint16_t ptr; + uint16_t is_leaf : 1; + /* index into phys_sections (is_leaf) or phys_map_nodes (!is_leaf) */ + uint16_t ptr : 15; }; /* Simple allocator for PhysPageEntry nodes */ static PhysPageEntry (*phys_map_nodes)[L2_SIZE]; static unsigned phys_map_nodes_nb, phys_map_nodes_nb_alloc; -#define PHYS_MAP_NODE_NIL ((uint16_t)~0) +#define PHYS_MAP_NODE_NIL (((uint16_t)~0) >> 1) /* This is a multi-level map on the physical address space. The bottom level has pointers to MemoryRegionSections. */ -static PhysPageEntry phys_map = { .ptr = PHYS_MAP_NODE_NIL }; +static PhysPageEntry phys_map = { .ptr = PHYS_MAP_NODE_NIL, .is_leaf = 0 }; static void io_mem_init(void); static void memory_map_init(void); @@ -423,6 +424,7 @@ static uint16_t phys_map_node_alloc(void) assert(ret != PHYS_MAP_NODE_NIL); assert(ret != phys_map_nodes_nb_alloc); for (i = 0; i < L2_SIZE; ++i) { + phys_map_nodes[ret][i].is_leaf = 0; phys_map_nodes[ret][i].ptr = PHYS_MAP_NODE_NIL; } return ret; @@ -440,12 +442,14 @@ static void phys_page_set_level(PhysPageEntry *lp, target_phys_addr_t *index, { PhysPageEntry *p; int i; + target_phys_addr_t step = (target_phys_addr_t)1 << (level * L2_BITS); - if (lp->ptr == PHYS_MAP_NODE_NIL) { + if (!lp->is_leaf && lp->ptr == PHYS_MAP_NODE_NIL) { lp->ptr = phys_map_node_alloc(); p = phys_map_nodes[lp->ptr]; if (level == 0) { for (i = 0; i < L2_SIZE; i++) { + p[i].is_leaf = 1; p[i].ptr = phys_section_unassigned; } } @@ -455,10 +459,11 @@ static void phys_page_set_level(PhysPageEntry *lp, target_phys_addr_t *index, lp = &p[(*index >> (level * L2_BITS)) & (L2_SIZE - 1)]; while (*nb && lp < &p[L2_SIZE]) { - if (level == 0) { + if ((*index & (step - 1)) == 0 && *nb >= step) { + lp->is_leaf = true; lp->ptr = leaf; - ++*index; - --*nb; + *index += step; + *nb -= step; } else { phys_page_set_level(lp, index, nb, leaf, level - 1); } @@ -470,7 +475,7 @@ static void phys_page_set(target_phys_addr_t index, target_phys_addr_t nb, uint16_t leaf) { /* Wildly overreserve - it doesn't matter much. */ - phys_map_node_reserve((nb + L2_SIZE - 1) / L2_SIZE * P_L2_LEVELS); + phys_map_node_reserve(3 * P_L2_LEVELS); phys_page_set_level(&phys_map, &index, &nb, leaf, P_L2_LEVELS - 1); } @@ -484,7 +489,7 @@ static MemoryRegionSection phys_page_find(target_phys_addr_t index) target_phys_addr_t delta; uint16_t s_index = phys_section_unassigned; - for (i = P_L2_LEVELS - 1; i >= 0; i--) { + for (i = P_L2_LEVELS - 1; i >= 0 && !lp.is_leaf; i--) { if (lp.ptr == PHYS_MAP_NODE_NIL) { goto not_found; } @@ -2580,12 +2585,13 @@ static void destroy_l2_mapping(PhysPageEntry *lp, unsigned level) p = phys_map_nodes[lp->ptr]; for (i = 0; i < L2_SIZE; ++i) { - if (level > 0) { + if (!p[i].is_leaf) { destroy_l2_mapping(&p[i], level - 1); } else { destroy_page_desc(p[i].ptr); } } + lp->is_leaf = 0; lp->ptr = PHYS_MAP_NODE_NIL; } |