diff options
Diffstat (limited to 'src/pmem.c')
| -rw-r--r-- | src/pmem.c | 40 |
1 files changed, 39 insertions, 1 deletions
@@ -436,11 +436,23 @@ static void __mark_area_used(pm_t base, pm_t top) mark_used(BASE_PAGE, runner); } +/** Helper for keeping track of which memory regions to avoid placing data into. */ struct avoid_region { + /** Base address of region. */ pm_t base; + + /** Size of region. */ pm_t size; }; +/** + * @param base1 + * @param size1 + * @param base2 + * @param size2 + * @return \ref true if the memory regions indicated have some overlap, + * \ref false otherwise. + */ static bool overlaps(pm_t base1, pm_t size1, pm_t base2, pm_t size2) { bool b = base1 >= base2 && base1 < base2 + size2; @@ -451,7 +463,11 @@ static bool overlaps(pm_t base1, pm_t size1, pm_t base2, pm_t size2) /** * Mark reserved memory region used, to avoid it getting accidentally allocated. * - * @param fdt Global FDT pointer. + * @param ram_base RAM base address in kernelspace. + * @param ram_size RAM size. + * @param avoid_count How many regions to avoid. + * @param avoid Regions to avoid. Should all be in kernelspace, everything + * outside RAM is ignored. */ static void __mark_reserved(pm_t ram_base, pm_t ram_size, size_t avoid_count, struct avoid_region avoid[64]) @@ -469,6 +485,15 @@ static void __mark_reserved(pm_t ram_base, pm_t ram_size, size_t avoid_count, } } +/** + * Figure out what if any regions of RAM are reserved and append them to \p + * avoid. + * + * @param exists How many elements are currently in \p avoid. + * @param avoid Array of regions to avoid, must not be sparse. + * @param fdt Flattened device tree. + * @return Total number of regions avoid. + */ static size_t build_reserved_map(size_t exists, struct avoid_region avoid[64], void *fdt) { @@ -490,6 +515,19 @@ static size_t build_reserved_map(size_t exists, struct avoid_region avoid[64], return exists; } +/** + * Selects a fitting base address for a block of memory of size \p size, while + * avoiding overwriting anything in \p avoid. + * Addresses to be avoided are allowed to be outside of RAM, + * for example in ROM, in which case they are just ignored. + * + * @param ram_base Base address of RAM. + * @param ram_size Size of RAM. + * @param size Size of block to find. + * @param avoid_count How many elements in the \p avoid array. + * @param avoid Which memory regions to avoid. + * @return A suitable base address, aligned on a word boundary. + */ static pm_t select_base(pm_t ram_base, pm_t ram_size, pm_t size, pm_t avoid_count, struct avoid_region avoid[64]) |