lib/arm64/call.h

/*
 * Adapted from Hafnium.
 * TODO: Figure out the right way of specifying the license.
 */

/*
 * Copyright 2018 The Hafnium Authors.
 *
 * Licensed under the Apache License, Version 2.0 (the "License");
 * you may not use this file except in compliance with the License.
 * You may obtain a copy of the License at
 *
 *     https://www.apache.org/licenses/LICENSE-2.0
 *
 * Unless required by applicable law or agreed to in writing, software
 * distributed under the License is distributed on an "AS IS" BASIS,
 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
 * See the License for the specific language governing permissions and
 * limitations under the License.
 */

#pragma once

#include "ffa.h"

/**
 * This function must be implemented to trigger the architecture-specific
 * mechanism to call to the hypervisor.
 */
struct ffa_value ffa_call(struct ffa_value args);

/**
 * Hafnium-specific hypervisor calling function.
 */
int64_t hf_call(uint64_t arg0, uint64_t arg1, uint64_t arg2, uint64_t arg3);

/**
 * Returns the VM's own ID.
 */
static inline struct ffa_value ffa_id_get(void)
{
	return ffa_call((struct ffa_value){.func = FFA_ID_GET_32});
}

/**
 * Runs the given vCPU of the given VM.
 */
static inline struct ffa_value ffa_run(ffa_vm_id_t vm_id,
				       ffa_vcpu_index_t vcpu_idx)
{
	return ffa_call((struct ffa_value){.func = FFA_RUN_32,
					   ffa_vm_vcpu(vm_id, vcpu_idx)});
}

/**
 * Hints that the vCPU is willing to yield its current use of the physical CPU.
 * This call always returns FFA_SUCCESS.
 */
static inline struct ffa_value ffa_yield(void)
{
	return ffa_call((struct ffa_value){.func = FFA_YIELD_32});
}

/**
 * Configures the pages to send/receive data through. The pages must not be
 * shared.
 *
 * Returns:
 *  - FFA_ERROR FFA_INVALID_PARAMETERS if the given addresses are not properly
 *    aligned or are the same.
 *  - FFA_ERROR FFA_NO_MEMORY if the hypervisor was unable to map the buffers
 *    due to insuffient page table memory.
 *  - FFA_ERROR FFA_DENIED if the pages are already mapped or are not owned by
 *    the caller.
 *  - FFA_SUCCESS on success if no further action is needed.
 *  - FFA_RX_RELEASE if it was called by the primary VM and the primary VM now
 *    needs to wake up or kick waiters.
 */
static inline struct ffa_value ffa_rxtx_map(phys_addr_t send, phys_addr_t recv)
{
	return ffa_call(
		(struct ffa_value){.func = FFA_RXTX_MAP_64,
				   .arg1 = send,
				   .arg2 = recv,
				   .arg3 = FFA_MAILBOX_SIZE / FFA_PAGE_SIZE});
}

/**
 * Copies data from the sender's send buffer to the recipient's receive buffer.
 *
 * If the recipient's receive buffer is busy, it can optionally register the
 * caller to be notified when the recipient's receive buffer becomes available.
 *
 * Attributes may include:
 *  - FFA_MSG_SEND_NOTIFY, to notify the caller when it should try again.
 *  - FFA_MSG_SEND_LEGACY_MEMORY_*, to send a legacy architected memory sharing
 *    message.
 *
 * Returns FFA_SUCCESS if the message is sent, or an error code otherwise:
 *  - INVALID_PARAMETERS: one or more of the parameters do not conform.
 *  - BUSY: the message could not be delivered either because the mailbox
 *    was full or the target VM is not yet set up.
 */
static inline struct ffa_value ffa_msg_send(ffa_vm_id_t sender_vm_id,
					    ffa_vm_id_t target_vm_id,
					    uint32_t size, uint32_t attributes)
{
	return ffa_call((struct ffa_value){
		.func = FFA_MSG_SEND_32,
		.arg1 = ((uint64_t)sender_vm_id << 16) | target_vm_id,
		.arg3 = size,
		.arg4 = attributes});
}

static inline struct ffa_value ffa_mem_donate(uint32_t length,
					      uint32_t fragment_length)
{
	return ffa_call((struct ffa_value){.func = FFA_MEM_DONATE_32,
					   .arg1 = length,
					   .arg2 = fragment_length});
}

static inline struct ffa_value ffa_mem_lend(uint32_t length,
					    uint32_t fragment_length)
{
	return ffa_call((struct ffa_value){.func = FFA_MEM_LEND_32,
					   .arg1 = length,
					   .arg2 = fragment_length});
}

static inline struct ffa_value ffa_mem_share(uint32_t length,
					     uint32_t fragment_length)
{
	return ffa_call((struct ffa_value){.func = FFA_MEM_SHARE_32,
					   .arg1 = length,
					   .arg2 = fragment_length});
}

static inline struct ffa_value ffa_mem_retrieve_req(uint32_t length,
						    uint32_t fragment_length)
{
	return ffa_call((struct ffa_value){.func = FFA_MEM_RETRIEVE_REQ_32,
					   .arg1 = length,
					   .arg2 = fragment_length});
}

static inline struct ffa_value ffa_mem_relinquish(void)
{
	return ffa_call((struct ffa_value){.func = FFA_MEM_RELINQUISH_32});
}

static inline struct ffa_value ffa_mem_reclaim(ffa_memory_handle_t handle,
					       ffa_memory_region_flags_t flags)
{
	return ffa_call((struct ffa_value){.func = FFA_MEM_RECLAIM_32,
					   .arg1 = (uint32_t)handle,
					   .arg2 = (uint32_t)(handle >> 32),
					   .arg3 = flags});
}

static inline struct ffa_value ffa_mem_frag_rx(ffa_memory_handle_t handle,
					       uint32_t fragment_offset)
{
	/* Note that sender MBZ at virtual instance. */
	return ffa_call((struct ffa_value){.func = FFA_MEM_FRAG_RX_32,
					   .arg1 = (uint32_t)handle,
					   .arg2 = (uint32_t)(handle >> 32),
					   .arg3 = fragment_offset});
}

static inline struct ffa_value ffa_mem_frag_tx(ffa_memory_handle_t handle,
					       uint32_t fragment_length)
{
	/* Note that sender MBZ at virtual instance. */
	return ffa_call((struct ffa_value){.func = FFA_MEM_FRAG_TX_32,
					   .arg1 = (uint32_t)handle,
					   .arg2 = (uint32_t)(handle >> 32),
					   .arg3 = fragment_length});
}

/**
 * Called by secondary VMs to receive a message. This will block until a message
 * is received.
 *
 * The mailbox must be cleared before a new message can be received.
 *
 * If no message is immediately available and there are no enabled and pending
 * interrupts (irrespective of whether interrupts are enabled globally), then
 * this will block until a message is available or an enabled interrupt becomes
 * pending. This matches the behaviour of the WFI instruction on AArch64, except
 * that a message becoming available is also treated like a wake-up event.
 *
 * Returns:
 *  - FFA_MSG_SEND if a message is successfully received.
 *  - FFA_ERROR FFA_NOT_SUPPORTED if called from the primary VM.
 *  - FFA_ERROR FFA_INTERRUPTED if an interrupt happened during the call.
 */
static inline struct ffa_value ffa_msg_wait(void)
{
	return ffa_call((struct ffa_value){.func = FFA_MSG_WAIT_32});
}

/**
 * Called by secondary VMs to receive a message. The call will return whether or
 * not a message is available.
 *
 * The mailbox must be cleared before a new message can be received.
 *
 * Returns:
 *  - FFA_MSG_SEND if a message is successfully received.
 *  - FFA_ERROR FFA_NOT_SUPPORTED if called from the primary VM.
 *  - FFA_ERROR FFA_INTERRUPTED if an interrupt happened during the call.
 *  - FFA_ERROR FFA_RETRY if there was no pending message.
 */
static inline struct ffa_value ffa_msg_poll(void)
{
	return ffa_call((struct ffa_value){.func = FFA_MSG_POLL_32});
}

/**
 * Releases the caller's mailbox so that a new message can be received. The
 * caller must have copied out all data they wish to preserve as new messages
 * will overwrite the old and will arrive asynchronously.
 *
 * Returns:
 *  - FFA_ERROR FFA_DENIED on failure, if the mailbox hasn't been read.
 *  - FFA_SUCCESS on success if no further action is needed.
 *  - FFA_RX_RELEASE if it was called by the primary VM and the primary VM now
 *    needs to wake up or kick waiters. Waiters should be retrieved by calling
 *    hf_mailbox_waiter_get.
 */
static inline struct ffa_value ffa_rx_release(void)
{
	return ffa_call((struct ffa_value){.func = FFA_RX_RELEASE_32});
}

/** Obtains the Hafnium's version of the implemented FF-A specification. */
static inline int32_t ffa_version(uint32_t requested_version)
{
	return ffa_call((struct ffa_value){.func = FFA_VERSION_32,
					   .arg1 = requested_version})
		.func;
}

/**
 * Discovery function returning information about the implementation of optional
 * FF-A interfaces.
 *
 * Returns:
 *  - FFA_SUCCESS in .func if the optional interface with function_id is
 * implemented.
 *  - FFA_ERROR in .func if the optional interface with function_id is not
 * implemented.
 */
static inline struct ffa_value ffa_features(uint32_t function_id)
{
	return ffa_call((struct ffa_value){.func = FFA_FEATURES_32,
					   .arg1 = function_id});
}