2 * Copyright (C) 2017 Oracle Corporation
4 * Permission is hereby granted, free of charge, to any person obtaining a
5 * copy of this software and associated documentation files (the
6 * "Software"), to deal in the Software without restriction, including
7 * without limitation the rights to use, copy, modify, merge, publish,
8 * distribute, sub license, and/or sell copies of the Software, and to
9 * permit persons to whom the Software is furnished to do so, subject to
10 * the following conditions:
12 * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
13 * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
14 * FITNESS FOR A PARTICULAR PURPOSE AND NON-INFRINGEMENT. IN NO EVENT SHALL
15 * THE COPYRIGHT HOLDERS, AUTHORS AND/OR ITS SUPPLIERS BE LIABLE FOR ANY CLAIM,
16 * DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR
17 * OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE
18 * USE OR OTHER DEALINGS IN THE SOFTWARE.
20 * The above copyright notice and this permission notice (including the
21 * next paragraph) shall be included in all copies or substantial portions
24 * Authors: Hans de Goede <hdegoede@redhat.com>
28 #include "vboxvideo_vbe.h"
29 #include "hgsmi_defs.h"
31 /* One-at-a-Time Hash from http://www.burtleburtle.net/bob/hash/doobs.html */
32 static u32 hgsmi_hash_process(u32 hash, const u8 *data, int size)
43 static u32 hgsmi_hash_end(u32 hash)
52 /* Not really a checksum but that is the naming used in all vbox code */
53 static u32 hgsmi_checksum(u32 offset,
54 const struct hgsmi_buffer_header *header,
55 const struct hgsmi_buffer_tail *tail)
59 checksum = hgsmi_hash_process(0, (u8 *)&offset, sizeof(offset));
60 checksum = hgsmi_hash_process(checksum, (u8 *)header, sizeof(*header));
61 /* 4 -> Do not checksum the checksum itself */
62 checksum = hgsmi_hash_process(checksum, (u8 *)tail, 4);
64 return hgsmi_hash_end(checksum);
67 void *hgsmi_buffer_alloc(struct gen_pool *guest_pool, size_t size,
68 u8 channel, u16 channel_info)
70 struct hgsmi_buffer_header *h;
71 struct hgsmi_buffer_tail *t;
75 total_size = size + sizeof(*h) + sizeof(*t);
76 h = gen_pool_dma_alloc(guest_pool, total_size, &offset);
80 t = (struct hgsmi_buffer_tail *)((u8 *)h + sizeof(*h) + size);
82 h->flags = HGSMI_BUFFER_HEADER_F_SEQ_SINGLE;
85 h->channel_info = channel_info;
86 memset(&h->u.header_data, 0, sizeof(h->u.header_data));
89 t->checksum = hgsmi_checksum(offset, h, t);
91 return (u8 *)h + sizeof(*h);
94 void hgsmi_buffer_free(struct gen_pool *guest_pool, void *buf)
96 struct hgsmi_buffer_header *h =
97 (struct hgsmi_buffer_header *)((u8 *)buf - sizeof(*h));
98 size_t total_size = h->data_size + sizeof(*h) +
99 sizeof(struct hgsmi_buffer_tail);
101 gen_pool_free(guest_pool, (unsigned long)h, total_size);
104 int hgsmi_buffer_submit(struct gen_pool *guest_pool, void *buf)
108 offset = gen_pool_virt_to_phys(guest_pool, (unsigned long)buf -
109 sizeof(struct hgsmi_buffer_header));
110 outl(offset, VGA_PORT_HGSMI_GUEST);
111 /* Make the compiler aware that the host has changed memory. */