efi_loader: carve out efi_get_memory_map_alloc()

Carve out code from efidebug command used to read the memory map.

Signed-off-by: Heinrich Schuchardt <heinrich.schuchardt@canonical.com>

3 files changed, 41 insertions, 14 deletions

diff --git a/cmd/efidebug.c b/cmd/efidebug.c
index 569003a..e6959ed 100644
--- a/cmd/efidebug.c
+++ b/cmd/efidebug.c
@@ -591,25 +591,15 @@ static void print_memory_attributes(u64 attributes)
 static int do_efi_show_memmap(struct cmd_tbl *cmdtp, int flag,
 			      int argc, char *const argv[])
 {
-	struct efi_mem_desc *memmap = NULL, *map;
-	efi_uintn_t map_size = 0;
+	struct efi_mem_desc *memmap, *map;
+	efi_uintn_t map_size;
 	const char *type;
 	int i;
 	efi_status_t ret;
 
-	ret = efi_get_memory_map(&map_size, memmap, NULL, NULL, NULL);
-	if (ret == EFI_BUFFER_TOO_SMALL) {
-		map_size += sizeof(struct efi_mem_desc); /* for my own */
-		ret = efi_allocate_pool(EFI_BOOT_SERVICES_DATA, map_size,
-					(void *)&memmap);
-		if (ret != EFI_SUCCESS)
-			return CMD_RET_FAILURE;
-		ret = efi_get_memory_map(&map_size, memmap, NULL, NULL, NULL);
-	}
-	if (ret != EFI_SUCCESS) {
-		efi_free_pool(memmap);
+	ret = efi_get_memory_map_alloc(&map_size, &memmap);
+	if (ret != EFI_SUCCESS)
 		return CMD_RET_FAILURE;
-	}
 
 	printf("Type             Start%.*s End%.*s Attributes\n",
 	       EFI_PHYS_ADDR_WIDTH - 5, spc, EFI_PHYS_ADDR_WIDTH - 3, spc);
diff --git a/include/efi_loader.h b/include/efi_loader.h
index 6991768..f9e427f 100644
--- a/include/efi_loader.h
+++ b/include/efi_loader.h
@@ -736,6 +736,9 @@ efi_status_t efi_allocate_pool(enum efi_memory_type pool_type,
 			       efi_uintn_t size, void **buffer);
 /* EFI pool memory free function. */
 efi_status_t efi_free_pool(void *buffer);
+/* Allocate and retrieve EFI memory map */
+efi_status_t efi_get_memory_map_alloc(efi_uintn_t *map_size,
+				      struct efi_mem_desc **memory_map);
 /* Returns the EFI memory map */
 efi_status_t efi_get_memory_map(efi_uintn_t *memory_map_size,
 				struct efi_mem_desc *memory_map,
diff --git a/lib/efi_loader/efi_memory.c b/lib/efi_loader/efi_memory.c
index 8d347f1..32254d2 100644
--- a/lib/efi_loader/efi_memory.c
+++ b/lib/efi_loader/efi_memory.c
@@ -737,6 +737,40 @@ efi_status_t efi_get_memory_map(efi_uintn_t *memory_map_size,
 }
 
 /**
+ * efi_get_memory_map_alloc() - allocate map describing memory usage
+ *
+ * The caller is responsible for calling FreePool() if the call succeeds.
+ *
+ * @memory_map		buffer to which the memory map is written
+ * @map_size		size of the memory map
+ * Return:		status code
+ */
+efi_status_t efi_get_memory_map_alloc(efi_uintn_t *map_size,
+				      struct efi_mem_desc **memory_map)
+{
+	efi_status_t ret;
+
+	*memory_map = NULL;
+	*map_size = 0;
+	ret = efi_get_memory_map(map_size, *memory_map, NULL, NULL, NULL);
+	if (ret == EFI_BUFFER_TOO_SMALL) {
+		*map_size += sizeof(struct efi_mem_desc); /* for the map */
+		ret = efi_allocate_pool(EFI_BOOT_SERVICES_DATA, *map_size,
+					(void **)memory_map);
+		if (ret != EFI_SUCCESS)
+			return ret;
+		ret = efi_get_memory_map(map_size, *memory_map,
+					 NULL, NULL, NULL);
+		if (ret != EFI_SUCCESS) {
+			efi_free_pool(*memory_map);
+			*memory_map = NULL;
+		}
+	}
+
+	return ret;
+}
+
+/**
  * efi_add_conventional_memory_map() - add a RAM memory area to the map
  *
  * @ram_start:		start address of a RAM memory area