diff --git a/drivers/firmware/efi/efi.c b/drivers/firmware/efi/efi.c index fad7c62cfc0e..415849bab233 100644 --- a/drivers/firmware/efi/efi.c +++ b/drivers/firmware/efi/efi.c @@ -969,13 +969,33 @@ bool efi_is_table_address(unsigned long phys_addr) static DEFINE_SPINLOCK(efi_mem_reserve_persistent_lock); static struct linux_efi_memreserve *efi_memreserve_root __ro_after_init; -int efi_mem_reserve_persistent(phys_addr_t addr, u64 size) +static int __init efi_memreserve_map_root(void) +{ + if (efi.mem_reserve == EFI_INVALID_TABLE_ADDR) + return -ENODEV; + + efi_memreserve_root = memremap(efi.mem_reserve, + sizeof(*efi_memreserve_root), + MEMREMAP_WB); + if (WARN_ON_ONCE(!efi_memreserve_root)) + return -ENOMEM; + return 0; +} + +int __ref efi_mem_reserve_persistent(phys_addr_t addr, u64 size) { struct linux_efi_memreserve *rsv; + int rc; - if (!efi_memreserve_root) + if (efi_memreserve_root == (void *)ULONG_MAX) return -ENODEV; + if (!efi_memreserve_root) { + rc = efi_memreserve_map_root(); + if (rc) + return rc; + } + rsv = kmalloc(sizeof(*rsv), GFP_ATOMIC); if (!rsv) return -ENOMEM; @@ -993,14 +1013,10 @@ int efi_mem_reserve_persistent(phys_addr_t addr, u64 size) static int __init efi_memreserve_root_init(void) { - if (efi.mem_reserve == EFI_INVALID_TABLE_ADDR) - return -ENODEV; - - efi_memreserve_root = memremap(efi.mem_reserve, - sizeof(*efi_memreserve_root), - MEMREMAP_WB); - if (!efi_memreserve_root) - return -ENOMEM; + if (efi_memreserve_root) + return 0; + if (efi_memreserve_map_root()) + efi_memreserve_root = (void *)ULONG_MAX; return 0; } early_initcall(efi_memreserve_root_init);