stored as file /ubootefi.var on the EFI system partition.
config EFI_MM_COMM_TEE
- bool "UEFI variables storage service via OP-TEE"
- depends on OPTEE
+ bool "UEFI variables storage service via the trusted world"
+ select ARM_FFA_TRANSPORT
+ select TEE
+ select OPTEE
help
+ Allowing access to the MM SP services (SPs such as StandAlonneMM, smm-gateway).
+ When using the u-boot OP-TEE driver, StandAlonneMM is supported.
+ When using the u-boot FF-A driver any MM SP is supported.
+
If OP-TEE is present and running StandAloneMM, dispatch all UEFI
variable related operations to that. The application will verify,
authenticate and store the variables on an RPMB.
+ When ARM_FFA_TRANSPORT is used, dispatch all UEFI variable related
+ operations to the MM SP running in the secure world.
+ A door bell mechanism is used to notify the SP when there is data in the shared
+ MM buffer. The data is copied by u-boot to the shared buffer before issuing
+ the door bell event.
+
+config FFA_SHARED_MM_BUF_SIZE
+ int "Memory size of the shared MM communication buffer"
+ default 0
+ depends on EFI_MM_COMM_TEE
+ help
+ This defines the size in bytes of the memory area reserved for the shared
+ buffer used for communication between the MM feature in U-Boot and
+ the MM SP in secure world.
+ The size of the memory region must be a multiple of the size of the maximum
+ translation granule size that is specified in the ID_AA64MMFR0_EL1 System register.
+ It is assumed that the MM SP knows the size of the shared MM communication buffer.
+
+config FFA_SHARED_MM_BUF_OFFSET
+ int "Data offset in the shared MM communication buffer"
+ default 0
+ depends on EFI_MM_COMM_TEE
+ help
+ This defines the offset in bytes of the data read or written to in the shared
+ buffer by the MM SP.
+
+config FFA_SHARED_MM_BUF_ADDR
+ hex "Define the address of the shared MM communication buffer"
+ default 0x0
+ depends on EFI_MM_COMM_TEE
+ help
+ This defines the address of the shared MM communication buffer
+ used for communication between the MM feature in U-Boot and
+ the MM SP in secure world.
+ It is assumed that the MM SP knows the address of the shared MM communication buffer.
+
config EFI_VARIABLE_NO_STORE
bool "Don't persist non-volatile UEFI variables"
help
*
* Copyright (C) 2019 Linaro Ltd. <sughosh.ganu@linaro.org>
* Copyright (C) 2019 Linaro Ltd. <ilias.apalodimas@linaro.org>
+ * Copyright 2022-2023 Arm Limited and/or its affiliates <open-source-office@arm.com>
+ *
+ * Authors:
+ * Abdellatif El Khlifi <abdellatif.elkhlifi@arm.com>
*/
#include <common.h>
+#include <arm_ffa.h>
+#include <cpu_func.h>
+#include <dm.h>
#include <efi.h>
#include <efi_api.h>
#include <efi_loader.h>
#include <efi_variable.h>
-#include <tee.h>
#include <malloc.h>
+#include <mapmem.h>
#include <mm_communication.h>
+#include <tee.h>
+
+/* MM return codes */
+#define MM_SUCCESS (0)
+#define MM_NOT_SUPPORTED (-1)
+#define MM_INVALID_PARAMETER (-2)
+#define MM_DENIED (-3)
+#define MM_NO_MEMORY (-5)
+static const char *mm_sp_svc_uuid = MM_SP_UUID;
+static u16 mm_sp_id;
extern struct efi_var_file __efi_runtime_data *efi_var_buf;
static efi_uintn_t max_buffer_size; /* comm + var + func + data */
static efi_uintn_t max_payload_size; /* func + data */
}
/**
- * mm_communicate() - Adjust the cmonnucation buffer to StandAlonneMM and send
+ * ffa_notify_mm_sp() - Announce there is data in the shared buffer
+ *
+ * Notify the MM partition in the trusted world that
+ * data is available in the shared buffer.
+ * This is a blocking call during which trusted world has exclusive access
+ * to the MM shared buffer.
+ *
+ * Return:
+ *
+ * 0 on success
+ */
+static int ffa_notify_mm_sp(void)
+{
+ struct ffa_send_direct_data msg = {0};
+ int ret;
+ int sp_event_ret;
+ struct udevice *dev;
+
+ ret = uclass_first_device_err(UCLASS_FFA, &dev);
+ if (ret) {
+ log_err("EFI: Cannot find FF-A bus device, notify MM SP failure\n");
+ return ret;
+ }
+
+ msg.data0 = CONFIG_FFA_SHARED_MM_BUF_OFFSET; /* x3 */
+
+ ret = ffa_sync_send_receive(dev, mm_sp_id, &msg, 1);
+ if (ret)
+ return ret;
+
+ sp_event_ret = msg.data0; /* x3 */
+
+ switch (sp_event_ret) {
+ case MM_SUCCESS:
+ ret = 0;
+ break;
+ case MM_NOT_SUPPORTED:
+ ret = -EINVAL;
+ break;
+ case MM_INVALID_PARAMETER:
+ ret = -EPERM;
+ break;
+ case MM_DENIED:
+ ret = -EACCES;
+ break;
+ case MM_NO_MEMORY:
+ ret = -EBUSY;
+ break;
+ default:
+ ret = -EACCES;
+ }
+
+ return ret;
+}
+
+/**
+ * ffa_discover_mm_sp_id() - Query the MM partition ID
+ *
+ * Use the FF-A driver to get the MM partition ID.
+ * If multiple partitions are found, use the first one.
+ * This is a boot time function.
+ *
+ * Return:
+ *
+ * 0 on success
+ */
+static int ffa_discover_mm_sp_id(void)
+{
+ u32 count = 0;
+ int ret;
+ struct ffa_partition_desc *descs;
+ struct udevice *dev;
+
+ ret = uclass_first_device_err(UCLASS_FFA, &dev);
+ if (ret) {
+ log_err("EFI: Cannot find FF-A bus device, MM SP discovery failure\n");
+ return ret;
+ }
+
+ /* Ask the driver to fill the buffer with the SPs info */
+ ret = ffa_partition_info_get(dev, mm_sp_svc_uuid, &count, &descs);
+ if (ret) {
+ log_err("EFI: Failure in querying SPs info (%d), MM SP discovery failure\n", ret);
+ return ret;
+ }
+
+ /* MM SPs found , use the first one */
+
+ mm_sp_id = descs[0].info.id;
+
+ log_info("EFI: MM partition ID 0x%x\n", mm_sp_id);
+
+ return 0;
+}
+
+/**
+ * ffa_mm_communicate() - Exchange EFI services data with the MM partition using FF-A
+ * @comm_buf: locally allocated communication buffer used for rx/tx
+ * @dsize: communication buffer size
+ *
+ * Issue a door bell event to notify the MM partition (SP) running in OP-TEE
+ * that there is data to read from the shared buffer.
+ * Communication with the MM SP is performed using FF-A transport.
+ * On the event, MM SP can read the data from the buffer and
+ * update the MM shared buffer with response data.
+ * The response data is copied back to the communication buffer.
+ *
+ * Return:
+ *
+ * EFI status code
+ */
+static efi_status_t ffa_mm_communicate(void *comm_buf, ulong comm_buf_size)
+{
+ ulong tx_data_size;
+ int ffa_ret;
+ efi_status_t efi_ret;
+ struct efi_mm_communicate_header *mm_hdr;
+ void *virt_shared_buf;
+
+ if (!comm_buf)
+ return EFI_INVALID_PARAMETER;
+
+ /* Discover MM partition ID at boot time */
+ if (!mm_sp_id && ffa_discover_mm_sp_id()) {
+ log_err("EFI: Failure to discover MM SP ID at boot time, FF-A MM comms failure\n");
+ return EFI_UNSUPPORTED;
+ }
+
+ mm_hdr = (struct efi_mm_communicate_header *)comm_buf;
+ tx_data_size = mm_hdr->message_len + sizeof(efi_guid_t) + sizeof(size_t);
+
+ if (comm_buf_size != tx_data_size || tx_data_size > CONFIG_FFA_SHARED_MM_BUF_SIZE)
+ return EFI_INVALID_PARAMETER;
+
+ /* Copy the data to the shared buffer */
+
+ virt_shared_buf = map_sysmem((phys_addr_t)CONFIG_FFA_SHARED_MM_BUF_ADDR, 0);
+ memcpy(virt_shared_buf, comm_buf, tx_data_size);
+
+ /*
+ * The secure world might have cache disabled for
+ * the device region used for shared buffer (which is the case for Optee).
+ * In this case, the secure world reads the data from DRAM.
+ * Let's flush the cache so the DRAM is updated with the latest data.
+ */
+#ifdef CONFIG_ARM64
+ invalidate_dcache_all();
+#endif
+
+ /* Announce there is data in the shared buffer */
+
+ ffa_ret = ffa_notify_mm_sp();
+
+ switch (ffa_ret) {
+ case 0: {
+ ulong rx_data_size;
+ /* Copy the MM SP response from the shared buffer to the communication buffer */
+ rx_data_size = ((struct efi_mm_communicate_header *)virt_shared_buf)->message_len +
+ sizeof(efi_guid_t) +
+ sizeof(size_t);
+
+ if (rx_data_size > comm_buf_size) {
+ efi_ret = EFI_OUT_OF_RESOURCES;
+ break;
+ }
+
+ memcpy(comm_buf, virt_shared_buf, rx_data_size);
+ efi_ret = EFI_SUCCESS;
+ break;
+ }
+ case -EINVAL:
+ efi_ret = EFI_DEVICE_ERROR;
+ break;
+ case -EPERM:
+ efi_ret = EFI_INVALID_PARAMETER;
+ break;
+ case -EACCES:
+ efi_ret = EFI_ACCESS_DENIED;
+ break;
+ case -EBUSY:
+ efi_ret = EFI_OUT_OF_RESOURCES;
+ break;
+ default:
+ efi_ret = EFI_ACCESS_DENIED;
+ }
+
+ unmap_sysmem(virt_shared_buf);
+ return efi_ret;
+}
+
+/**
+ * get_mm_comms() - detect the available MM transport
+ *
+ * Make sure the FF-A bus is probed successfully
+ * which means FF-A communication with secure world works and ready
+ * for use.
+ *
+ * If FF-A bus is not ready, use OPTEE comms.
+ *
+ * Return:
+ *
+ * MM_COMMS_FFA or MM_COMMS_OPTEE
+ */
+static enum mm_comms_select get_mm_comms(void)
+{
+ struct udevice *dev;
+ int ret;
+
+ ret = uclass_first_device_err(UCLASS_FFA, &dev);
+ if (ret) {
+ log_err("EFI: Cannot find FF-A bus device, trying Optee comms\n");
+ return MM_COMMS_OPTEE;
+ }
+
+ return MM_COMMS_FFA;
+}
+
+/**
+ * mm_communicate() - Adjust the communication buffer to the MM SP and send
* it to OP-TEE
*
- * @comm_buf: locally allocted communcation buffer
+ * @comm_buf: locally allocated communication buffer
* @dsize: buffer size
+ *
+ * The SP (also called partition) can be any MM SP such as StandAlonneMM or smm-gateway.
+ * The comm_buf format is the same for both partitions.
+ * When using the u-boot OP-TEE driver, StandAlonneMM is supported.
+ * When using the u-boot FF-A driver, any MM SP is supported.
+ *
* Return: status code
*/
static efi_status_t mm_communicate(u8 *comm_buf, efi_uintn_t dsize)
{
efi_status_t ret;
+ enum mm_comms_select mm_comms;
struct efi_mm_communicate_header *mm_hdr;
struct smm_variable_communicate_header *var_hdr;
mm_hdr = (struct efi_mm_communicate_header *)comm_buf;
var_hdr = (struct smm_variable_communicate_header *)mm_hdr->data;
- ret = optee_mm_communicate(comm_buf, dsize);
+ mm_comms = get_mm_comms();
+ if (mm_comms == MM_COMMS_FFA)
+ ret = ffa_mm_communicate(comm_buf, dsize);
+ else
+ ret = optee_mm_communicate(comm_buf, dsize);
+
if (ret != EFI_SUCCESS) {
log_err("%s failed!\n", __func__);
return ret;
ret = EFI_NOT_FOUND;
if (ret != EFI_SUCCESS)
- log_err("Unable to notify StMM for ExitBootServices\n");
+ log_err("Unable to notify the MM partition for ExitBootServices\n");
free(comm_buf);
/*
projects / u-boot.git / commitdiff