1 files changed, 58 insertions, 1 deletions

diff --git a/drivers/firmware/efi/efi.c b/drivers/firmware/efi/efi.c
index 2a29dd9c986d..249eb70691b0 100644
--- a/drivers/firmware/efi/efi.c
+++ b/drivers/firmware/efi/efi.c
@@ -52,7 +52,8 @@ struct efi __read_mostly efi = {
 	.properties_table	= EFI_INVALID_TABLE_ADDR,
 	.mem_attr_table		= EFI_INVALID_TABLE_ADDR,
 	.rng_seed		= EFI_INVALID_TABLE_ADDR,
-	.tpm_log		= EFI_INVALID_TABLE_ADDR
+	.tpm_log		= EFI_INVALID_TABLE_ADDR,
+	.mem_reserve		= EFI_INVALID_TABLE_ADDR,
 };
 EXPORT_SYMBOL(efi);
 
@@ -484,6 +485,7 @@ static __initdata efi_config_table_type_t common_tables[] = {
 	{EFI_MEMORY_ATTRIBUTES_TABLE_GUID, "MEMATTR", &efi.mem_attr_table},
 	{LINUX_EFI_RANDOM_SEED_TABLE_GUID, "RNG", &efi.rng_seed},
 	{LINUX_EFI_TPM_EVENT_LOG_GUID, "TPMEventLog", &efi.tpm_log},
+	{LINUX_EFI_MEMRESERVE_TABLE_GUID, "MEMRESERVE", &efi.mem_reserve},
 	{NULL_GUID, NULL, NULL},
 };
 
@@ -591,6 +593,29 @@ int __init efi_config_parse_tables(void *config_tables, int count, int sz,
 		early_memunmap(tbl, sizeof(*tbl));
 	}
 
+	if (efi.mem_reserve != EFI_INVALID_TABLE_ADDR) {
+		unsigned long prsv = efi.mem_reserve;
+
+		while (prsv) {
+			struct linux_efi_memreserve *rsv;
+
+			/* reserve the entry itself */
+			memblock_reserve(prsv, sizeof(*rsv));
+
+			rsv = early_memremap(prsv, sizeof(*rsv));
+			if (rsv == NULL) {
+				pr_err("Could not map UEFI memreserve entry!\n");
+				return -ENOMEM;
+			}
+
+			if (rsv->size)
+				memblock_reserve(rsv->base, rsv->size);
+
+			prsv = rsv->next;
+			early_memunmap(rsv, sizeof(*rsv));
+		}
+	}
+
 	return 0;
 }
 
@@ -937,6 +962,38 @@ bool efi_is_table_address(unsigned long phys_addr)
 	return false;
 }
 
+static DEFINE_SPINLOCK(efi_mem_reserve_persistent_lock);
+
+int efi_mem_reserve_persistent(phys_addr_t addr, u64 size)
+{
+	struct linux_efi_memreserve *rsv, *parent;
+
+	if (efi.mem_reserve == EFI_INVALID_TABLE_ADDR)
+		return -ENODEV;
+
+	rsv = kmalloc(sizeof(*rsv), GFP_KERNEL);
+	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);
+	spin_unlock(&efi_mem_reserve_persistent_lock);
+
+	memunmap(parent);
+
+	return 0;
+}
+
 #ifdef CONFIG_KEXEC
 static int update_efi_random_seed(struct notifier_block *nb,
 				  unsigned long code, void *unused)