source: mainline/boot/arch/riscv64/src/ucb.c@ ae8d7b0

lfn serial ticket/834-toolchain-update topic/msim-upgrade topic/simplify-dev-export
Last change on this file since ae8d7b0 was ae8d7b0, checked in by Martin Decky <martin@…>, 8 years ago

riscv64: update to the latest Privileged Architecture specification (1.10)

  • Property mode set to 100644
File size: 1.9 KB
Line 
1/*
2 * Copyright (c) 2016 Martin Decky
3 * All rights reserved.
4 *
5 * Redistribution and use in source and binary forms, with or without
6 * modification, are permitted provided that the following conditions
7 * are met:
8 *
9 * - Redistributions of source code must retain the above copyright
10 * notice, this list of conditions and the following disclaimer.
11 * - Redistributions in binary form must reproduce the above copyright
12 * notice, this list of conditions and the following disclaimer in the
13 * documentation and/or other materials provided with the distribution.
14 * - The name of the author may not be used to endorse or promote products
15 * derived from this software without specific prior written permission.
16 *
17 * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR
18 * IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
19 * OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED.
20 * IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT,
21 * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT
22 * NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
23 * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
24 * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
25 * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF
26 * THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
27 */
28
29#include <arch/ucb.h>
30#include <arch/arch.h>
31#include <macros.h>
32
33volatile uint64_t tohost __attribute__((section(".htif")));
34volatile uint64_t fromhost __attribute__((section(".htif")));
35
36static void poll_fromhost()
37{
38 uint64_t val = fromhost;
39 if (!val)
40 return;
41
42 fromhost = 0;
43}
44
45void htif_cmd(uint8_t device, uint8_t cmd, uint64_t payload)
46{
47 uint64_t val = (((uint64_t) device) << 56) |
48 (((uint64_t) cmd) << 48) |
49 (payload & UINT64_C(0xffffffffffff));
50
51 while (tohost)
52 poll_fromhost();
53
54 tohost = val;
55}
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