1 files changed, 19 insertions, 12 deletions

diff --git a/drivers/firmware/efi/efi.c b/drivers/firmware/efi/efi.c
index 72a4da76d274..fad7c62cfc0e 100644
--- a/drivers/firmware/efi/efi.c
+++ b/drivers/firmware/efi/efi.c
@@ -967,36 +967,43 @@ 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)
 {
-        struct linux_efi_memreserve *rsv, *parent;
+        struct linux_efi_memreserve *rsv;
 
-        if (efi.mem_reserve == EFI_INVALID_TABLE_ADDR)
+        if (!efi_memreserve_root)
                 return -ENODEV;
 
-        rsv = kmalloc(sizeof(*rsv), GFP_KERNEL);
+        rsv = kmalloc(sizeof(*rsv), GFP_ATOMIC);
         if (!rsv)
                 return -ENOMEM;
 
-        parent = memremap(efi.mem_reserve, sizeof(*rsv), MEMREMAP_WB);
-        if (!parent) {
-                kfree(rsv);
-                return -ENOMEM;
-        }
-
         rsv->base = addr;
         rsv->size = size;
 
         spin_lock(&efi_mem_reserve_persistent_lock);
-        rsv->next = parent->next;
-        parent->next = __pa(rsv);
+        rsv->next = efi_memreserve_root->next;
+        efi_memreserve_root->next = __pa(rsv);
         spin_unlock(&efi_mem_reserve_persistent_lock);
 
-        memunmap(parent);
+        return 0;
+}
 
+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;
         return 0;
 }
+early_initcall(efi_memreserve_root_init);
 
 #ifdef CONFIG_KEXEC
 static int update_efi_random_seed(struct notifier_block *nb,