There are events that would be used to notify other interested modules of any changes in available and occupied memory. This would happen when a module allocates or reserves memory, or frees up memory. These changes in memory map should be notified to other interested modules so that the allocated memory does not get overwritten. Add an event handler in the EFI memory module to update the EFI memory map accordingly when such changes happen. As a consequence, any subsequent memory request would honour the updated memory map and only available memory would be allocated from.
Signed-off-by: Sughosh Ganu <[email protected]> --- lib/efi_loader/Kconfig | 2 ++ lib/efi_loader/efi_memory.c | 35 +++++++++++++++++++++++++++++++++++ 2 files changed, 37 insertions(+) diff --git a/lib/efi_loader/Kconfig b/lib/efi_loader/Kconfig index 911d4c6bbe..41d51987c3 100644 --- a/lib/efi_loader/Kconfig +++ b/lib/efi_loader/Kconfig @@ -16,9 +16,11 @@ config EFI_LOADER select CHARSET # We need to send DM events, dynamically, in the EFI block driver select DM_EVENT + select EVENT select EVENT_DYNAMIC select LIB_UUID select LMB + select MEM_MAP_UPDATE_NOTIFY imply PARTITION_UUIDS select REGEX imply FAT diff --git a/lib/efi_loader/efi_memory.c b/lib/efi_loader/efi_memory.c index 90e07ed6a2..900d3c12f1 100644 --- a/lib/efi_loader/efi_memory.c +++ b/lib/efi_loader/efi_memory.c @@ -44,6 +44,10 @@ static LIST_HEAD(efi_mem); void *efi_bounce_buffer; #endif +#define MAP_OP_RESERVE (u8)0x1 +#define MAP_OP_FREE (u8)0x2 +#define MAP_OP_ADD (u8)0x3 + /** * struct efi_pool_allocation - memory block allocated from pool * @@ -919,3 +923,34 @@ int efi_memory_init(void) return 0; } + +#if CONFIG_IS_ENABLED(MEM_MAP_UPDATE_NOTIFY) +static int lmb_mem_map_update_sync(void *ctx, struct event *event) +{ + u8 op; + u64 addr; + u64 pages; + efi_status_t status; + struct event_lmb_map_update *lmb_map = &event->data.lmb_map; + + addr = (uintptr_t)map_sysmem(lmb_map->base, 0); + pages = efi_size_in_pages(lmb_map->size + (addr & EFI_PAGE_MASK)); + op = lmb_map->op; + addr &= ~EFI_PAGE_MASK; + + if (op != MAP_OP_RESERVE && op != MAP_OP_FREE && op != MAP_OP_ADD) { + log_debug("Invalid map update op received (%d)\n", op); + return -1; + } + + status = efi_add_memory_map_pg(addr, pages, + op == MAP_OP_RESERVE ? + EFI_BOOT_SERVICES_DATA : + EFI_CONVENTIONAL_MEMORY, + op == MAP_OP_RESERVE ? true : false); + + return status == EFI_SUCCESS ? 0 : -1; +} + +EVENT_SPY_FULL(EVT_LMB_MAP_UPDATE, lmb_mem_map_update_sync); +#endif /* MEM_MAP_UPDATE_NOTIFY */ -- 2.34.1
