diff options
| -rw-r--r-- | memory.c | 62 | ||||
| -rw-r--r-- | memory.h | 39 |
2 files changed, 101 insertions, 0 deletions
@@ -515,6 +515,20 @@ static AddressSpace address_space_io = { .ops = &address_space_ops_io, }; +static AddressSpace *memory_region_to_address_space(MemoryRegion *mr) +{ + while (mr->parent) { + mr = mr->parent; + } + if (mr == address_space_memory.root) { + return &address_space_memory; + } + if (mr == address_space_io.root) { + return &address_space_io; + } + abort(); +} + /* Render a memory region into the global view. Ranges in @view obscure * ranges in @mr. */ @@ -1386,6 +1400,54 @@ void memory_region_set_alias_offset(MemoryRegion *mr, target_phys_addr_t offset) memory_region_update_topology(mr); } +static int cmp_flatrange_addr(const void *addr_, const void *fr_) +{ + const AddrRange *addr = addr_; + const FlatRange *fr = fr_; + + if (int128_le(addrrange_end(*addr), fr->addr.start)) { + return -1; + } else if (int128_ge(addr->start, addrrange_end(fr->addr))) { + return 1; + } + return 0; +} + +static FlatRange *address_space_lookup(AddressSpace *as, AddrRange addr) +{ + return bsearch(&addr, as->current_map.ranges, as->current_map.nr, + sizeof(FlatRange), cmp_flatrange_addr); +} + +MemoryRegionSection memory_region_find(MemoryRegion *address_space, + target_phys_addr_t addr, uint64_t size) +{ + AddressSpace *as = memory_region_to_address_space(address_space); + AddrRange range = addrrange_make(int128_make64(addr), + int128_make64(size)); + FlatRange *fr = address_space_lookup(as, range); + MemoryRegionSection ret = { .mr = NULL, .size = 0 }; + + if (!fr) { + return ret; + } + + while (fr > as->current_map.ranges + && addrrange_intersects(fr[-1].addr, range)) { + --fr; + } + + ret.mr = fr->mr; + range = addrrange_intersection(range, fr->addr); + ret.offset_within_region = fr->offset_in_region; + ret.offset_within_region += int128_get64(int128_sub(range.start, + fr->addr.start)); + ret.size = int128_get64(range.size); + ret.offset_within_address_space = int128_get64(range.start); + return ret; +} + + void set_system_memory_map(MemoryRegion *mr) { address_space_memory.root = mr; @@ -148,6 +148,24 @@ struct MemoryRegionPortio { #define PORTIO_END_OF_LIST() { } +typedef struct MemoryRegionSection MemoryRegionSection; + +/** + * MemoryRegionSection: describes a fragment of a #MemoryRegion + * + * @mr: the region, or %NULL if empty + * @offset_within_region: the beginning of the section, relative to @mr's start + * @size: the size of the section; will not exceed @mr's boundaries + * @offset_within_address_space: the address of the first byte of the section + * relative to the region's address space + */ +struct MemoryRegionSection { + MemoryRegion *mr; + target_phys_addr_t offset_within_region; + uint64_t size; + target_phys_addr_t offset_within_address_space; +}; + /** * memory_region_init: Initialize a memory region * @@ -569,6 +587,27 @@ void memory_region_set_alias_offset(MemoryRegion *mr, target_phys_addr_t offset); /** + * memory_region_find: locate a MemoryRegion in an address space + * + * Locates the first #MemoryRegion within an address space given by + * @address_space that overlaps the range given by @addr and @size. + * + * Returns a #MemoryRegionSection that describes a contiguous overlap. + * It will have the following characteristics: + * .@offset_within_address_space >= @addr + * .@offset_within_address_space + .@size <= @addr + @size + * .@size = 0 iff no overlap was found + * .@mr is non-%NULL iff an overlap was found + * + * @address_space: a top-level (i.e. parentless) region that contains + * the region to be found + * @addr: start of the area within @address_space to be searched + * @size: size of the area to be searched + */ +MemoryRegionSection memory_region_find(MemoryRegion *address_space, + target_phys_addr_t addr, uint64_t size); + +/** * memory_region_transaction_begin: Start a transaction. * * During a transaction, changes will be accumulated and made visible |