blob: 28a49256765b303f9116c550edb3a5da0d8f0ef0 [file] [log] [blame]
/*
* Copyright (c) 2022, Arm Limited. All rights reserved.
*
* SPDX-License-Identifier: BSD-3-Clause
*/
#include <stdint.h>
#include <string.h>
#include <common/debug.h>
#include <drivers/arm/mhu.h>
#include <drivers/arm/rss_comms.h>
#include <initial_attestation.h>
#include <psa/client.h>
#include <platform_def.h>
#define TYPE_OFFSET U(16)
#define TYPE_MASK (0xFFFFUL << TYPE_OFFSET)
#define IN_LEN_OFFSET U(8)
#define IN_LEN_MASK (0xFFUL << IN_LEN_OFFSET)
#define OUT_LEN_OFFSET U(0)
#define OUT_LEN_MASK (0xFFUL << OUT_LEN_OFFSET)
#define PARAM_PACK(type, in_len, out_len) \
(((((uint32_t)type) << TYPE_OFFSET) & TYPE_MASK) | \
((((uint32_t)in_len) << IN_LEN_OFFSET) & IN_LEN_MASK) | \
((((uint32_t)out_len) << OUT_LEN_OFFSET) & OUT_LEN_MASK))
#define PARAM_UNPACK_IN_LEN(ctrl_param) \
((size_t)(((ctrl_param) & IN_LEN_MASK) >> IN_LEN_OFFSET))
/* Message types */
struct __packed packed_psa_call_t {
uint8_t protocol_ver;
uint8_t seq_num;
uint16_t client_id;
psa_handle_t handle;
uint32_t ctrl_param; /* type, in_len, out_len */
uint16_t io_size[4];
};
struct __packed packed_psa_reply_t {
uint8_t protocol_ver;
uint8_t seq_num;
uint16_t client_id;
int32_t return_val;
uint16_t out_size[4];
};
/*
* In the current implementation the RoT Service request that requires the
* biggest message buffer is the RSS_ATTEST_GET_TOKEN. The maximum required
* buffer size is calculated based on the platform-specific needs of
* this request.
*/
#define MAX_REQUEST_PAYLOAD_SIZE (PSA_INITIAL_ATTEST_CHALLENGE_SIZE_64 \
+ PLAT_ATTEST_TOKEN_MAX_SIZE)
/* Buffer to store the messages to be sent/received. */
static uint8_t message_buf[MAX_REQUEST_PAYLOAD_SIZE] __aligned(4);
static int32_t pack_params(const psa_invec *invecs,
size_t in_len,
uint8_t *buf,
size_t *buf_len)
{
uint32_t i;
size_t payload_size = 0U;
for (i = 0U; i < in_len; ++i) {
if (invecs[i].len > *buf_len - payload_size) {
return -1;
}
memcpy(buf + payload_size, invecs[i].base, invecs[i].len);
payload_size += invecs[i].len;
}
*buf_len = payload_size;
return 0;
}
static int serialise_message(const struct packed_psa_call_t *msg,
const psa_invec *invecs,
uint8_t *payload_buf,
size_t *payload_len)
{
size_t message_len = 0U;
size_t len;
/* Copy the message header into the payload buffer. */
len = sizeof(*msg);
if (len > *payload_len) {
ERROR("[RSS-COMMS] Message buffer too small.\n");
return -1;
}
memcpy(payload_buf, (const void *)msg, len);
message_len += len;
/* The input data will follow the message header in the payload buffer. */
len = *payload_len - message_len;
if (pack_params(invecs, PARAM_UNPACK_IN_LEN(msg->ctrl_param),
payload_buf + message_len, &len) != 0) {
ERROR("[RSS-COMMS] Message buffer too small.\n");
return -1;
}
message_len += len;
*payload_len = message_len;
return 0;
}
static void unpack_params(const uint8_t *buf,
psa_outvec *outvecs,
size_t out_len)
{
size_t i;
for (i = 0U; i < out_len; ++i) {
memcpy(outvecs[i].base, buf, outvecs[i].len);
buf += outvecs[i].len;
}
}
static void deserialise_reply(struct packed_psa_reply_t *reply,
psa_outvec *outvecs,
size_t outlen,
const uint8_t *message,
size_t message_len)
{
uint32_t i;
memcpy(reply, message, sizeof(*reply));
/* Outvecs */
for (i = 0U; i < outlen; ++i) {
outvecs[i].len = reply->out_size[i];
}
unpack_params(message + sizeof(*reply), outvecs, outlen);
}
psa_status_t psa_call(psa_handle_t handle, int32_t type,
const psa_invec *in_vec, size_t in_len,
psa_outvec *out_vec, size_t out_len)
{
enum mhu_error_t err;
static uint32_t seq_num = 1U;
struct packed_psa_call_t msg = {
.protocol_ver = 0U,
.seq_num = seq_num,
/* No need to distinguish callers (currently concurrent calls are not supported). */
.client_id = 1U,
.handle = handle,
.ctrl_param = PARAM_PACK(type, in_len, out_len),
};
struct packed_psa_reply_t reply = {0};
size_t message_size;
uint32_t i;
/* Fill msg iovec lengths */
for (i = 0U; i < in_len; ++i) {
msg.io_size[i] = in_vec[i].len;
}
for (i = 0U; i < out_len; ++i) {
msg.io_size[in_len + i] = out_vec[i].len;
}
message_size = sizeof(message_buf);
if (serialise_message(&msg, in_vec, message_buf, &message_size)) {
/* Local buffer is probably too small. */
return PSA_ERROR_INSUFFICIENT_MEMORY;
}
err = mhu_send_data(message_buf, message_size);
if (err != MHU_ERR_NONE) {
return PSA_ERROR_COMMUNICATION_FAILURE;
}
message_size = sizeof(message_buf);
#if DEBUG
/*
* Poisoning the message buffer (with a known pattern).
* Helps in detecting hypothetical RSS communication bugs.
*/
memset(message_buf, 0xA5, message_size);
#endif
err = mhu_receive_data(message_buf, &message_size);
if (err != MHU_ERR_NONE) {
return PSA_ERROR_COMMUNICATION_FAILURE;
}
deserialise_reply(&reply, out_vec, out_len, message_buf, message_size);
seq_num++;
VERBOSE("[RSS-COMMS] Received reply\n");
VERBOSE("protocol_ver=%d\n", reply.protocol_ver);
VERBOSE("seq_num=%d\n", reply.seq_num);
VERBOSE("client_id=%d\n", reply.client_id);
VERBOSE("return_val=%d\n", reply.return_val);
VERBOSE("out_size[0]=%d\n", reply.out_size[0]);
return reply.return_val;
}
int rss_comms_init(uintptr_t mhu_sender_base, uintptr_t mhu_receiver_base)
{
enum mhu_error_t err;
err = mhu_init_sender(mhu_sender_base);
if (err != MHU_ERR_NONE) {
ERROR("[RSS-COMMS] Host to RSS MHU driver initialization failed: %d\n", err);
return -1;
}
err = mhu_init_receiver(mhu_receiver_base);
if (err != MHU_ERR_NONE) {
ERROR("[RSS-COMMS] RSS to Host MHU driver initialization failed: %d\n", err);
return -1;
}
return 0;
}