[PATCH v3 2/2] efi_loader: support fmp versioning for multi bank update

[Masahisa Kojima]

This commit stores the firmware version into the array
of fmp_state structure to support the fmp versioning
for multi bank update. The index of the array is identified
by the bank index.

This modification keeps the backward compatibility with
the existing versioning feature.

Signed-off-by: Masahisa Kojima <masahisa.kojima at linaro.org>
---
 lib/efi_loader/efi_firmware.c | 75 ++++++++++++++++++++++++++++-------
 1 file changed, 60 insertions(+), 15 deletions(-)

diff --git a/lib/efi_loader/efi_firmware.c b/lib/efi_loader/efi_firmware.c
index e558336bc1..9fd13297a6 100644
--- a/lib/efi_loader/efi_firmware.c
+++ b/lib/efi_loader/efi_firmware.c
@@ -206,18 +206,10 @@ void efi_firmware_fill_version_info(struct efi_firmware_image_descriptor *image_
 {
 	u16 varname[13]; /* u"FmpStateXXXX" */
 	efi_status_t ret;
-	efi_uintn_t size;
-	struct fmp_state var_state = { 0 };
-
-	efi_create_indexed_name(varname, sizeof(varname), "FmpState",
-				fw_array->image_index);
-	size = sizeof(var_state);
-	ret = efi_get_variable_int(varname, &fw_array->image_type_id,
-				   NULL, &size, &var_state, NULL);
-	if (ret == EFI_SUCCESS)
-		image_info->version = var_state.fw_version;
-	else
-		image_info->version = 0;
+	efi_uintn_t size, expected_size;
+	uint num_banks = 1;
+	uint active_index = 0;
+	struct fmp_state *var_state;
 
 	efi_firmware_get_lsv_from_dtb(fw_array->image_index,
 				      &fw_array->image_type_id,
@@ -226,6 +218,31 @@ void efi_firmware_fill_version_info(struct efi_firmware_image_descriptor *image_
 	image_info->version_name = NULL; /* not supported */
 	image_info->last_attempt_version = 0;
 	image_info->last_attempt_status = LAST_ATTEMPT_STATUS_SUCCESS;
+	image_info->version = 0;
+
+	/* get the fw_version */
+	efi_create_indexed_name(varname, sizeof(varname), "FmpState",
+				fw_array->image_index);
+	if (IS_ENABLED(CONFIG_FWU_MULTI_BANK_UPDATE)) {
+		ret = fwu_get_active_index(&active_index);
+		if (ret)
+			return;
+
+		num_banks = CONFIG_FWU_NUM_BANKS;
+	}
+
+	size = num_banks * sizeof(*var_state);
+	expected_size = size;
+	var_state = calloc(1, size);
+	if (!var_state)
+		return;
+
+	ret = efi_get_variable_int(varname, &fw_array->image_type_id,
+				   NULL, &size, var_state, NULL);
+	if (ret == EFI_SUCCESS && expected_size == size)
+		image_info->version = var_state[active_index].fw_version;
+
+	free(var_state);
 }
 
 /**
@@ -361,8 +378,11 @@ efi_status_t efi_firmware_set_fmp_state_var(struct fmp_state *state, u8 image_in
 {
 	u16 varname[13]; /* u"FmpStateXXXX" */
 	efi_status_t ret;
+	uint num_banks = 1;
+	uint update_bank = 0;
+	efi_uintn_t size;
 	efi_guid_t *image_type_id;
-	struct fmp_state var_state = { 0 };
+	struct fmp_state *var_state;
 
 	image_type_id = efi_firmware_get_image_type_id(image_index);
 	if (!image_type_id)
@@ -371,19 +391,44 @@ efi_status_t efi_firmware_set_fmp_state_var(struct fmp_state *state, u8 image_in
 	efi_create_indexed_name(varname, sizeof(varname), "FmpState",
 				image_index);
 
+	if (IS_ENABLED(CONFIG_FWU_MULTI_BANK_UPDATE)) {
+		ret = fwu_plat_get_update_index(&update_bank);
+		if (ret)
+			return EFI_INVALID_PARAMETER;
+
+		num_banks = CONFIG_FWU_NUM_BANKS;
+	}
+
+	size = num_banks * sizeof(*var_state);
+	var_state = calloc(1, size);
+	if (!var_state)
+		return EFI_OUT_OF_RESOURCES;
+
+	/*
+	 * GetVariable may fail, EFI_NOT_FOUND is returned if FmpState
+	 * variable has not been set yet.
+	 * Ignore the error here since the correct FmpState variable
+	 * is set later.
+	 */
+	efi_get_variable_int(varname, image_type_id, NULL, &size, var_state,
+			     NULL);
+
 	/*
 	 * Only the fw_version is set here.
 	 * lowest_supported_version in FmpState variable is ignored since
 	 * it can be tampered if the file based EFI variable storage is used.
 	 */
-	var_state.fw_version = state->fw_version;
+	var_state[update_bank].fw_version = state->fw_version;
 
+	size = num_banks * sizeof(*var_state);
 	ret = efi_set_variable_int(varname, image_type_id,
 				   EFI_VARIABLE_READ_ONLY |
 				   EFI_VARIABLE_NON_VOLATILE |
 				   EFI_VARIABLE_BOOTSERVICE_ACCESS |
 				   EFI_VARIABLE_RUNTIME_ACCESS,
-				   sizeof(var_state), &var_state, false);
+				   size, var_state, false);
+
+	free(var_state);
 
 	return ret;
 }
-- 
2.34.1