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path: root/drivers/gpu/drm/vboxvideo/vbox_hgsmi.c
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Diffstat (limited to 'drivers/gpu/drm/vboxvideo/vbox_hgsmi.c')
-rw-r--r--drivers/gpu/drm/vboxvideo/vbox_hgsmi.c95
1 files changed, 95 insertions, 0 deletions
diff --git a/drivers/gpu/drm/vboxvideo/vbox_hgsmi.c b/drivers/gpu/drm/vboxvideo/vbox_hgsmi.c
new file mode 100644
index 000000000000..94b60654a012
--- /dev/null
+++ b/drivers/gpu/drm/vboxvideo/vbox_hgsmi.c
@@ -0,0 +1,95 @@
+// SPDX-License-Identifier: MIT
+/*
+ * Copyright (C) 2017 Oracle Corporation
+ * 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;
+}