efi/arm/libstub: Make screen_info accessible to the UEFI stub

[people/arne_f/kernel.git] / drivers / firmware / efi / libstub / arm32-stub.c

diff --git a/drivers/firmware/efi/libstub/arm32-stub.c b/drivers/firmware/efi/libstub/arm32-stub.c
index 6f42be4d0084f1befcceb329758513b5f2c50781..e1f0b28e1dcbbf9cde9a1e882ba6212fb165c55e 100644 (file)
--- a/drivers/firmware/efi/libstub/arm32-stub.c
+++ b/drivers/firmware/efi/libstub/arm32-stub.c
@@ -26,6 +26,43 @@ efi_status_t check_platform_features(efi_system_table_t *sys_table_arg)
        return EFI_SUCCESS;
 }
 
+static efi_guid_t screen_info_guid = LINUX_EFI_ARM_SCREEN_INFO_TABLE_GUID;
+
+struct screen_info *alloc_screen_info(efi_system_table_t *sys_table_arg)
+{
+       struct screen_info *si;
+       efi_status_t status;
+
+       /*
+        * Unlike on arm64, where we can directly fill out the screen_info
+        * structure from the stub, we need to allocate a buffer to hold
+        * its contents while we hand over to the kernel proper from the
+        * decompressor.
+        */
+       status = efi_call_early(allocate_pool, EFI_RUNTIME_SERVICES_DATA,
+                               sizeof(*si), (void **)&si);
+
+       if (status != EFI_SUCCESS)
+               return NULL;
+
+       status = efi_call_early(install_configuration_table,
+                               &screen_info_guid, si);
+       if (status == EFI_SUCCESS)
+               return si;
+
+       efi_call_early(free_pool, si);
+       return NULL;
+}
+
+void free_screen_info(efi_system_table_t *sys_table_arg, struct screen_info *si)
+{
+       if (!si)
+               return;
+
+       efi_call_early(install_configuration_table, &screen_info_guid, NULL);
+       efi_call_early(free_pool, si);
+}
+
 efi_status_t handle_kernel_image(efi_system_table_t *sys_table,
                                 unsigned long *image_addr,
                                 unsigned long *image_size,