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Diffstat (limited to '')
| -rw-r--r-- | drivers/arm/rss/rss_comms.c | 170 |
1 files changed, 170 insertions, 0 deletions
diff --git a/drivers/arm/rss/rss_comms.c b/drivers/arm/rss/rss_comms.c new file mode 100644 index 0000000..5e224e1 --- /dev/null +++ b/drivers/arm/rss/rss_comms.c @@ -0,0 +1,170 @@ +/* + * 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 <psa/client.h> +#include <rss_comms_protocol.h> + +/* Union as message space and reply space are never used at the same time, and this saves space as + * we can overlap them. + */ +union __packed __attribute__((aligned(4))) rss_comms_io_buffer_t { + struct serialized_rss_comms_msg_t msg; + struct serialized_rss_comms_reply_t reply; +}; + +static uint8_t select_protocol_version(const psa_invec *in_vec, size_t in_len, + const psa_outvec *out_vec, size_t out_len) +{ + size_t comms_mhu_msg_size; + size_t comms_embed_msg_min_size; + size_t comms_embed_reply_min_size; + size_t in_size_total = 0; + size_t out_size_total = 0; + size_t i; + + for (i = 0U; i < in_len; ++i) { + in_size_total += in_vec[i].len; + } + for (i = 0U; i < out_len; ++i) { + out_size_total += out_vec[i].len; + } + + comms_mhu_msg_size = mhu_get_max_message_size(); + + comms_embed_msg_min_size = sizeof(struct serialized_rss_comms_header_t) + + sizeof(struct rss_embed_msg_t) - + PLAT_RSS_COMMS_PAYLOAD_MAX_SIZE; + + comms_embed_reply_min_size = sizeof(struct serialized_rss_comms_header_t) + + sizeof(struct rss_embed_reply_t) - + PLAT_RSS_COMMS_PAYLOAD_MAX_SIZE; + + /* Use embed if we can pack into one message and reply, else use + * pointer_access. The underlying MHU transport protocol uses a + * single uint32_t to track the length, so the amount of data that + * can be in a message is 4 bytes less than mhu_get_max_message_size + * reports. + * + * TODO tune this with real performance numbers, it's possible a + * pointer_access message is less performant than multiple embed + * messages due to ATU configuration costs to allow access to the + * pointers. + */ + if ((comms_embed_msg_min_size + in_size_total > comms_mhu_msg_size - sizeof(uint32_t)) + || (comms_embed_reply_min_size + out_size_total > comms_mhu_msg_size) - sizeof(uint32_t)) { + return RSS_COMMS_PROTOCOL_POINTER_ACCESS; + } else { + return RSS_COMMS_PROTOCOL_EMBED; + } +} + +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) +{ + /* Declared statically to avoid using huge amounts of stack space. Maybe revisit if + * functions not being reentrant becomes a problem. + */ + static union rss_comms_io_buffer_t io_buf; + enum mhu_error_t err; + psa_status_t status; + static uint8_t seq_num = 1U; + size_t msg_size; + size_t reply_size = sizeof(io_buf.reply); + psa_status_t return_val; + size_t idx; + + if (type > INT16_MAX || type < INT16_MIN || in_len > PSA_MAX_IOVEC + || out_len > PSA_MAX_IOVEC) { + return PSA_ERROR_INVALID_ARGUMENT; + } + + io_buf.msg.header.seq_num = seq_num, + /* No need to distinguish callers (currently concurrent calls are not supported). */ + io_buf.msg.header.client_id = 1U, + io_buf.msg.header.protocol_ver = select_protocol_version(in_vec, in_len, out_vec, out_len); + + status = rss_protocol_serialize_msg(handle, type, in_vec, in_len, out_vec, + out_len, &io_buf.msg, &msg_size); + if (status != PSA_SUCCESS) { + return status; + } + + VERBOSE("[RSS-COMMS] Sending message\n"); + VERBOSE("protocol_ver=%u\n", io_buf.msg.header.protocol_ver); + VERBOSE("seq_num=%u\n", io_buf.msg.header.seq_num); + VERBOSE("client_id=%u\n", io_buf.msg.header.client_id); + for (idx = 0; idx < in_len; idx++) { + VERBOSE("in_vec[%lu].len=%lu\n", idx, in_vec[idx].len); + VERBOSE("in_vec[%lu].buf=%p\n", idx, (void *)in_vec[idx].base); + } + + err = mhu_send_data((uint8_t *)&io_buf.msg, msg_size); + if (err != MHU_ERR_NONE) { + return PSA_ERROR_COMMUNICATION_FAILURE; + } + +#if DEBUG + /* + * Poisoning the message buffer (with a known pattern). + * Helps in detecting hypothetical RSS communication bugs. + */ + memset(&io_buf.msg, 0xA5, msg_size); +#endif + + err = mhu_receive_data((uint8_t *)&io_buf.reply, &reply_size); + if (err != MHU_ERR_NONE) { + return PSA_ERROR_COMMUNICATION_FAILURE; + } + + VERBOSE("[RSS-COMMS] Received reply\n"); + VERBOSE("protocol_ver=%u\n", io_buf.reply.header.protocol_ver); + VERBOSE("seq_num=%u\n", io_buf.reply.header.seq_num); + VERBOSE("client_id=%u\n", io_buf.reply.header.client_id); + + status = rss_protocol_deserialize_reply(out_vec, out_len, &return_val, + &io_buf.reply, reply_size); + if (status != PSA_SUCCESS) { + return status; + } + + VERBOSE("return_val=%d\n", return_val); + for (idx = 0U; idx < out_len; idx++) { + VERBOSE("out_vec[%lu].len=%lu\n", idx, out_vec[idx].len); + VERBOSE("out_vec[%lu].buf=%p\n", idx, (void *)out_vec[idx].base); + } + + /* Clear the MHU message buffer to remove assets from memory */ + memset(&io_buf, 0x0, sizeof(io_buf)); + + seq_num++; + + return 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; +} |