| /* |
| * Copyright (C) 2017 Oracle Corporation |
| * |
| * Permission is hereby granted, free of charge, to any person obtaining a |
| * copy of this software and associated documentation files (the |
| * "Software"), to deal in the Software without restriction, including |
| * without limitation the rights to use, copy, modify, merge, publish, |
| * distribute, sub license, and/or sell copies of the Software, and to |
| * permit persons to whom the Software is furnished to do so, subject to |
| * the following conditions: |
| * |
| * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR |
| * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY, |
| * FITNESS FOR A PARTICULAR PURPOSE AND NON-INFRINGEMENT. IN NO EVENT SHALL |
| * THE COPYRIGHT HOLDERS, AUTHORS AND/OR ITS SUPPLIERS BE LIABLE FOR ANY CLAIM, |
| * DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR |
| * OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE |
| * USE OR OTHER DEALINGS IN THE SOFTWARE. |
| * |
| * The above copyright notice and this permission notice (including the |
| * next paragraph) shall be included in all copies or substantial portions |
| * of the Software. |
| * |
| * Authors: Hans de Goede <hdegoede@redhat.com> |
| */ |
| |
| #include "vbox_drv.h" |
| #include "vboxvideo_vbe.h" |
| #include "hgsmi_defs.h" |
| |
| /* One-at-a-Time Hash from http://www.burtleburtle.net/bob/hash/doobs.html */ |
| static u32 hgsmi_hash_process(u32 hash, const u8 *data, int size) |
| { |
| while (size--) { |
| hash += *data++; |
| hash += (hash << 10); |
| hash ^= (hash >> 6); |
| } |
| |
| return hash; |
| } |
| |
| static u32 hgsmi_hash_end(u32 hash) |
| { |
| hash += (hash << 3); |
| hash ^= (hash >> 11); |
| hash += (hash << 15); |
| |
| return hash; |
| } |
| |
| /* Not really a checksum but that is the naming used in all vbox code */ |
| static u32 hgsmi_checksum(u32 offset, |
| const struct hgsmi_buffer_header *header, |
| const struct hgsmi_buffer_tail *tail) |
| { |
| u32 checksum; |
| |
| checksum = hgsmi_hash_process(0, (u8 *)&offset, sizeof(offset)); |
| checksum = hgsmi_hash_process(checksum, (u8 *)header, sizeof(*header)); |
| /* 4 -> Do not checksum the checksum itself */ |
| checksum = hgsmi_hash_process(checksum, (u8 *)tail, 4); |
| |
| return hgsmi_hash_end(checksum); |
| } |
| |
| void *hgsmi_buffer_alloc(struct gen_pool *guest_pool, size_t size, |
| u8 channel, u16 channel_info) |
| { |
| struct hgsmi_buffer_header *h; |
| struct hgsmi_buffer_tail *t; |
| size_t total_size; |
| dma_addr_t offset; |
| |
| total_size = size + sizeof(*h) + sizeof(*t); |
| h = gen_pool_dma_alloc(guest_pool, total_size, &offset); |
| if (!h) |
| return NULL; |
| |
| t = (struct hgsmi_buffer_tail *)((u8 *)h + sizeof(*h) + size); |
| |
| h->flags = HGSMI_BUFFER_HEADER_F_SEQ_SINGLE; |
| h->data_size = size; |
| h->channel = channel; |
| h->channel_info = channel_info; |
| memset(&h->u.header_data, 0, sizeof(h->u.header_data)); |
| |
| t->reserved = 0; |
| t->checksum = hgsmi_checksum(offset, h, t); |
| |
| return (u8 *)h + sizeof(*h); |
| } |
| |
| void hgsmi_buffer_free(struct gen_pool *guest_pool, void *buf) |
| { |
| struct hgsmi_buffer_header *h = |
| (struct hgsmi_buffer_header *)((u8 *)buf - sizeof(*h)); |
| size_t total_size = h->data_size + sizeof(*h) + |
| sizeof(struct hgsmi_buffer_tail); |
| |
| gen_pool_free(guest_pool, (unsigned long)h, total_size); |
| } |
| |
| int hgsmi_buffer_submit(struct gen_pool *guest_pool, void *buf) |
| { |
| phys_addr_t offset; |
| |
| offset = gen_pool_virt_to_phys(guest_pool, (unsigned long)buf - |
| sizeof(struct hgsmi_buffer_header)); |
| outl(offset, VGA_PORT_HGSMI_GUEST); |
| /* Make the compiler aware that the host has changed memory. */ |
| mb(); |
| |
| return 0; |
| } |