1 /*
2 * Copyright (C) 2017 Oracle Corporation
3 *
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:
11 *
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.
19 *
20 * The above copyright notice and this permission notice (including the
21 * next paragraph) shall be included in all copies or substantial portions
22 * of the Software.
23 *
24 * Authors: Hans de Goede <hdegoede@redhat.com>
25 */
26
27 #include "vbox_drv.h"
28 #include "vboxvideo_vbe.h"
29 #include "hgsmi_defs.h"
30
31 /* One-at-a-Time Hash from http://www.burtleburtle.net/bob/hash/doobs.html */
hgsmi_hash_process(u32 hash,const u8 * data,int size)32 static u32 hgsmi_hash_process(u32 hash, const u8 *data, int size)
33 {
34 while (size--) {
35 hash += *data++;
36 hash += (hash << 10);
37 hash ^= (hash >> 6);
38 }
39
40 return hash;
41 }
42
hgsmi_hash_end(u32 hash)43 static u32 hgsmi_hash_end(u32 hash)
44 {
45 hash += (hash << 3);
46 hash ^= (hash >> 11);
47 hash += (hash << 15);
48
49 return hash;
50 }
51
52 /* Not really a checksum but that is the naming used in all vbox code */
hgsmi_checksum(u32 offset,const struct hgsmi_buffer_header * header,const struct hgsmi_buffer_tail * tail)53 static u32 hgsmi_checksum(u32 offset,
54 const struct hgsmi_buffer_header *header,
55 const struct hgsmi_buffer_tail *tail)
56 {
57 u32 checksum;
58
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);
63
64 return hgsmi_hash_end(checksum);
65 }
66
hgsmi_buffer_alloc(struct gen_pool * guest_pool,size_t size,u8 channel,u16 channel_info)67 void *hgsmi_buffer_alloc(struct gen_pool *guest_pool, size_t size,
68 u8 channel, u16 channel_info)
69 {
70 struct hgsmi_buffer_header *h;
71 struct hgsmi_buffer_tail *t;
72 size_t total_size;
73 dma_addr_t offset;
74
75 total_size = size + sizeof(*h) + sizeof(*t);
76 h = gen_pool_dma_alloc(guest_pool, total_size, &offset);
77 if (!h)
78 return NULL;
79
80 t = (struct hgsmi_buffer_tail *)((u8 *)h + sizeof(*h) + size);
81
82 h->flags = HGSMI_BUFFER_HEADER_F_SEQ_SINGLE;
83 h->data_size = size;
84 h->channel = channel;
85 h->channel_info = channel_info;
86 memset(&h->u.header_data, 0, sizeof(h->u.header_data));
87
88 t->reserved = 0;
89 t->checksum = hgsmi_checksum(offset, h, t);
90
91 return (u8 *)h + sizeof(*h);
92 }
93
hgsmi_buffer_free(struct gen_pool * guest_pool,void * buf)94 void hgsmi_buffer_free(struct gen_pool *guest_pool, void *buf)
95 {
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);
100
101 gen_pool_free(guest_pool, (unsigned long)h, total_size);
102 }
103
hgsmi_buffer_submit(struct gen_pool * guest_pool,void * buf)104 int hgsmi_buffer_submit(struct gen_pool *guest_pool, void *buf)
105 {
106 phys_addr_t offset;
107
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. */
112 mb();
113
114 return 0;
115 }
116