efi: libstub: simplify efi_get_memory_map() and struct efi_boot_memmap

Currently, struct efi_boot_memmap is a struct that is passed around
between callers of efi_get_memory_map() and the users of the resulting
data, and which carries pointers to various variables whose values are
provided by the EFI GetMemoryMap() boot service.

This is overly complex, and it is much easier to carry these values in
the struct itself. So turn the struct into one that carries these data
items directly, including a flex array for the variable number of EFI
memory descriptors that the boot service may return.

Signed-off-by: Ard Biesheuvel <ardb@kernel.org>

1 files changed, 5 insertions, 15 deletions

diff --git a/drivers/firmware/efi/libstub/x86-stub.c b/drivers/firmware/efi/libstub/x86-stub.c
index 05ae8bcc9d67..1ae1e7e576b9 100644
--- a/drivers/firmware/efi/libstub/x86-stub.c
+++ b/drivers/firmware/efi/libstub/x86-stub.c
@@ -716,32 +716,22 @@ static efi_status_t exit_boot_func(struct efi_boot_memmap *map,
 
 	efi_set_u64_split((unsigned long)efi_system_table,
 			  &p->efi->efi_systab, &p->efi->efi_systab_hi);
-	p->efi->efi_memdesc_size	= *map->desc_size;
-	p->efi->efi_memdesc_version	= *map->desc_ver;
-	efi_set_u64_split((unsigned long)*map->map,
+	p->efi->efi_memdesc_size	= map->desc_size;
+	p->efi->efi_memdesc_version	= map->desc_ver;
+	efi_set_u64_split((unsigned long)map->map,
 			  &p->efi->efi_memmap, &p->efi->efi_memmap_hi);
-	p->efi->efi_memmap_size		= *map->map_size;
+	p->efi->efi_memmap_size		= map->map_size;
 
 	return EFI_SUCCESS;
 }
 
 static efi_status_t exit_boot(struct boot_params *boot_params, void *handle)
 {
-	unsigned long map_sz, key, desc_size, buff_size;
-	efi_memory_desc_t *mem_map;
 	struct setup_data *e820ext = NULL;
 	__u32 e820ext_size = 0;
 	efi_status_t status;
-	__u32 desc_version;
-	struct efi_boot_memmap map;
 	struct exit_boot_struct priv;
 
-	map.map			= &mem_map;
-	map.map_size		= &map_sz;
-	map.desc_size		= &desc_size;
-	map.desc_ver		= &desc_version;
-	map.key_ptr		= &key;
-	map.buff_size		= &buff_size;
 	priv.boot_params	= boot_params;
 	priv.efi		= &boot_params->efi_info;
 
@@ -750,7 +740,7 @@ static efi_status_t exit_boot(struct boot_params *boot_params, void *handle)
 		return status;
 
 	/* Might as well exit boot services now */
-	status = efi_exit_boot_services(handle, &map, &priv, exit_boot_func);
+	status = efi_exit_boot_services(handle, &priv, exit_boot_func);
 	if (status != EFI_SUCCESS)
 		return status;