1*4882a593Smuzhiyun // SPDX-License-Identifier: MIT
2*4882a593Smuzhiyun /*
3*4882a593Smuzhiyun * Copyright (C) 2017 Oracle Corporation
4*4882a593Smuzhiyun * Authors: Hans de Goede <hdegoede@redhat.com>
5*4882a593Smuzhiyun */
6*4882a593Smuzhiyun
7*4882a593Smuzhiyun #include "vbox_drv.h"
8*4882a593Smuzhiyun #include "vboxvideo_vbe.h"
9*4882a593Smuzhiyun #include "hgsmi_defs.h"
10*4882a593Smuzhiyun
11*4882a593Smuzhiyun /* One-at-a-Time Hash from https://www.burtleburtle.net/bob/hash/doobs.html */
hgsmi_hash_process(u32 hash,const u8 * data,int size)12*4882a593Smuzhiyun static u32 hgsmi_hash_process(u32 hash, const u8 *data, int size)
13*4882a593Smuzhiyun {
14*4882a593Smuzhiyun while (size--) {
15*4882a593Smuzhiyun hash += *data++;
16*4882a593Smuzhiyun hash += (hash << 10);
17*4882a593Smuzhiyun hash ^= (hash >> 6);
18*4882a593Smuzhiyun }
19*4882a593Smuzhiyun
20*4882a593Smuzhiyun return hash;
21*4882a593Smuzhiyun }
22*4882a593Smuzhiyun
hgsmi_hash_end(u32 hash)23*4882a593Smuzhiyun static u32 hgsmi_hash_end(u32 hash)
24*4882a593Smuzhiyun {
25*4882a593Smuzhiyun hash += (hash << 3);
26*4882a593Smuzhiyun hash ^= (hash >> 11);
27*4882a593Smuzhiyun hash += (hash << 15);
28*4882a593Smuzhiyun
29*4882a593Smuzhiyun return hash;
30*4882a593Smuzhiyun }
31*4882a593Smuzhiyun
32*4882a593Smuzhiyun /* 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)33*4882a593Smuzhiyun static u32 hgsmi_checksum(u32 offset,
34*4882a593Smuzhiyun const struct hgsmi_buffer_header *header,
35*4882a593Smuzhiyun const struct hgsmi_buffer_tail *tail)
36*4882a593Smuzhiyun {
37*4882a593Smuzhiyun u32 checksum;
38*4882a593Smuzhiyun
39*4882a593Smuzhiyun checksum = hgsmi_hash_process(0, (u8 *)&offset, sizeof(offset));
40*4882a593Smuzhiyun checksum = hgsmi_hash_process(checksum, (u8 *)header, sizeof(*header));
41*4882a593Smuzhiyun /* 4 -> Do not checksum the checksum itself */
42*4882a593Smuzhiyun checksum = hgsmi_hash_process(checksum, (u8 *)tail, 4);
43*4882a593Smuzhiyun
44*4882a593Smuzhiyun return hgsmi_hash_end(checksum);
45*4882a593Smuzhiyun }
46*4882a593Smuzhiyun
hgsmi_buffer_alloc(struct gen_pool * guest_pool,size_t size,u8 channel,u16 channel_info)47*4882a593Smuzhiyun void *hgsmi_buffer_alloc(struct gen_pool *guest_pool, size_t size,
48*4882a593Smuzhiyun u8 channel, u16 channel_info)
49*4882a593Smuzhiyun {
50*4882a593Smuzhiyun struct hgsmi_buffer_header *h;
51*4882a593Smuzhiyun struct hgsmi_buffer_tail *t;
52*4882a593Smuzhiyun size_t total_size;
53*4882a593Smuzhiyun dma_addr_t offset;
54*4882a593Smuzhiyun
55*4882a593Smuzhiyun total_size = size + sizeof(*h) + sizeof(*t);
56*4882a593Smuzhiyun h = gen_pool_dma_alloc(guest_pool, total_size, &offset);
57*4882a593Smuzhiyun if (!h)
58*4882a593Smuzhiyun return NULL;
59*4882a593Smuzhiyun
60*4882a593Smuzhiyun t = (struct hgsmi_buffer_tail *)((u8 *)h + sizeof(*h) + size);
61*4882a593Smuzhiyun
62*4882a593Smuzhiyun h->flags = HGSMI_BUFFER_HEADER_F_SEQ_SINGLE;
63*4882a593Smuzhiyun h->data_size = size;
64*4882a593Smuzhiyun h->channel = channel;
65*4882a593Smuzhiyun h->channel_info = channel_info;
66*4882a593Smuzhiyun memset(&h->u.header_data, 0, sizeof(h->u.header_data));
67*4882a593Smuzhiyun
68*4882a593Smuzhiyun t->reserved = 0;
69*4882a593Smuzhiyun t->checksum = hgsmi_checksum(offset, h, t);
70*4882a593Smuzhiyun
71*4882a593Smuzhiyun return (u8 *)h + sizeof(*h);
72*4882a593Smuzhiyun }
73*4882a593Smuzhiyun
hgsmi_buffer_free(struct gen_pool * guest_pool,void * buf)74*4882a593Smuzhiyun void hgsmi_buffer_free(struct gen_pool *guest_pool, void *buf)
75*4882a593Smuzhiyun {
76*4882a593Smuzhiyun struct hgsmi_buffer_header *h =
77*4882a593Smuzhiyun (struct hgsmi_buffer_header *)((u8 *)buf - sizeof(*h));
78*4882a593Smuzhiyun size_t total_size = h->data_size + sizeof(*h) +
79*4882a593Smuzhiyun sizeof(struct hgsmi_buffer_tail);
80*4882a593Smuzhiyun
81*4882a593Smuzhiyun gen_pool_free(guest_pool, (unsigned long)h, total_size);
82*4882a593Smuzhiyun }
83*4882a593Smuzhiyun
hgsmi_buffer_submit(struct gen_pool * guest_pool,void * buf)84*4882a593Smuzhiyun int hgsmi_buffer_submit(struct gen_pool *guest_pool, void *buf)
85*4882a593Smuzhiyun {
86*4882a593Smuzhiyun phys_addr_t offset;
87*4882a593Smuzhiyun
88*4882a593Smuzhiyun offset = gen_pool_virt_to_phys(guest_pool, (unsigned long)buf -
89*4882a593Smuzhiyun sizeof(struct hgsmi_buffer_header));
90*4882a593Smuzhiyun outl(offset, VGA_PORT_HGSMI_GUEST);
91*4882a593Smuzhiyun /* Make the compiler aware that the host has changed memory. */
92*4882a593Smuzhiyun mb();
93*4882a593Smuzhiyun
94*4882a593Smuzhiyun return 0;
95*4882a593Smuzhiyun }
96